The Analysis of 

Regulated Contaminant 

Occurrence Data from 

Public Water Systems in 

Support of the Second 

Six-Year Review of 

National Primary Drinking 

Water Regulations 
Office of Water (4607M)

EPA-815-B-09-006 

Revised September 2010 

www.epa.gov/safewater
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Disclaimer 

This report is in support of the preliminary revise/take no action decisions for EPA’s

Second Six-Year Review of Existing Drinking Water Standards Federal Register Notice. This 

report is intended to provide technical background for the second Six-Year Review. 

This document is not a regulation itself, and it does not substitute for the Safe Drinking 

Water Act (SDWA) or EPA’s regulations. Mention of trade names or commercial products does 

not constitute endorsement or recommendation for use. 

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Acknowledgements 

EPA’s Office of Ground Water and Drinking Water (OGWDW) conducted the national 

assessments of regulated contaminant occurrence in public drinking water presented in this 

report in support of the second Six-Year Review of National Primary Drinking Water 

Regulations. This effort was directed by Ms. Karen Wirth and Mr. Rajiv Khera. 

EPA would like to thank the many states, territories, and tribes and their staff who 

contributed datasets and valuable advice during EPA’s compilation and review of the 

contaminant occurrence (compliance monitoring) data. Thank you also to the many public water 

systems and their staff who conducted the monitoring that provided the extensive amount of 

regulated contaminant occurrence data used in this report. 

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Executive Summary

The 1996 Amendments to the Safe Drinking Water Act (SDWA) require that the 

Environmental Protection Agency (EPA) “shall, at least once every six years, review and revise, 

as appropriate, each National Primary Drinking Water Regulation (NPDWR).” The NPDWRs 

are often referred to as the national drinking water contaminant regulations or drinking water 

standards. The ‘Six-Year Review’ process is an assessment of new information on the health 

effects and national occurrence, and the new capabilities of treatment technologies and 

laboratory analytical methods for the regulated contaminants. Through this process, EPA 

determines whether the new information and technical capabilities provide a scientific basis to 

support a revision of existing regulations that will improve public health protection. 

This report presents the national contaminant occurrence assessments conducted in 

support of EPA’s second Six-Year Review of NPDWRs. Included are detailed descriptions of the 

national contaminant occurrence dataset compiled, the data management procedures conducted 

to develop the national dataset, and the statistical analytical methods employed (using the 

national dataset) to generate national estimates of regulated contaminant occurrence in public 

drinking water systems. 

Because there is no national database that receives and stores all relevant data regarding 

the occurrence of regulated contaminants in public drinking water systems, EPA conducted a 

voluntary data call-in from the states, territories, and tribes to obtain the data. EPA worked with 

the states and primacy agencies to receive the states’ and agencies’ complete records of 

compliance monitoring data (public drinking water system regulated contaminant occurrence 

data) for 1998 through 2005. The compliance monitoring data were obtained through the 

Information Collection Request (ICR) process. 

Data management and quality assurance evaluations were conducted on all data received 

to establish a high quality, national contaminant occurrence dataset consisting of data from 47 

states/primacy agencies (45 states plus Region 8 and Region 9 tribes). The contaminant 

occurrence data from these 47 entities comprise more than 15 million analytical records from 

approximately 132,000 public water systems (PWSs) that serve approximately 254 million 

people nationally. This dataset, the National Compliance Monitoring ICR Dataset for the second 

Six-Year Review (or “Six-Year Review-ICR Dataset”), is the largest and most comprehensive 

contaminant occurrence dataset ever compiled and analyzed by EPA’s Drinking Water Program.

A two-stage analytical approach was conducted to estimate national contaminant 

occurrence using the Six-Year Review-ICR Dataset. In the first stage of analysis (the “Stage 1 

analysis”), the occurrence data were reviewed, quality-checked, characterized, and then analyzed 

to generate simple non-parametric estimates of national contaminant occurrence in PWSs. 

Simple counts were made of the number and percentage of systems, and population served by 

systems, with at least one compliance monitoring sample result greater than a specified 

contaminant concentration threshold. This Stage 1 analysis, based on maximum sample 

concentration values, is inherently conservative; it is designed not to underestimate contaminant 

occurrence for the consideration of public health protection. The Stage 1 analysis provides 

occurrence assessments that may be more reflective of potential acute exposure. EPA selected a 
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set of contaminants and also conducted additional parametric statistical estimations (the “Stage 2 

analyses”). The Stage 2 analysis estimates long-term mean concentrations of contaminants in all 

systems nationwide, generating occurrence analyses that are less conservative than the Stage 1 

analysis. The Stage 2 analysis also provides occurrence assessments that may be more reflective 

of potential chronic exposure. 

Stage 1 analyses of approximate peak concentration measures were used to assess the 

national occurrence of 65 regulated chemical and 4 radiological contaminants. Additional Stage 

2 analyses using mean concentration measures were conducted for 22 of the 65 regulated 

chemical contaminants. Several different variations of the Stage 1 and Stage 2 analyses were 

conducted to broadly characterize national occurrence and are described and presented in this 

report and its appendices. One variation of Stage 1 analyses estimates the percentage of 

population served by systems nationwide that reported at least one sample analytical result 

greater than the concentration equal to a contaminant’s Maximum Contaminant Level (MCL; the 

contaminant’s drinking water standard). Using this measure, the range of occurrence and the top 

five occurring regulated contaminants were estimated and summarized below grouped by 

inorganic chemicals (IOCs), synthetic organic chemicals (SOCs), and volatile organic chemicals 

(VOCs). The Stage 1 occurrence analyses conducted in this report, based roughly on peak 

occurrence, are different from the occurrence analyses formally conducted to assess compliance 

with contaminant drinking water standards (see Section 5.3 for details). 

IOC occurrence based on the Stage 1 analysis relative to the MCL concentration ranged 

from a high of nitrate with 7.310% of the total population served by systems reporting at least 

one detection greater than the nitrate MCL concentration to the low of barium with 0.092% of 

the total population served by systems reporting at least one detection greater than the barium 

MCL concentration. The top five occurring IOCs based on this Stage 1 MCL measure are nitrate 

(7.310%), nitrite (4.840%), antimony (1.505%), beryllium (1.386%), and arsenic (1.240%). The 

percentage of arsenic relative to the MCL concentration is based on the former MCL of 0.05 

mg/L.

SOC occurrence (based on the same Stage 1 analysis relative to the MCL concentration)

ranged from a high of di(2-ethylhexyl)phthalate with 6.397% of the total population served by 

systems reporting at least one detection greater than the MCL concentration to a low of no 

detections greater than the MCL concentrations for carbofuran, diquat, glyphosate, 

hexachlorocyclopentadiene, methoxychlor, picloram and 2,4,5-trichlorophenoxypropionic acid 

(silvex). The top five occurring SOCs based on this Stage 1 MCL measure are di(2-

ethylhexyl)phthalate (6.397%), 1,2-dibromo-3-chloropropane (DBCP) (1.627%), atrazine 

(1.551%), ethylene dibromide (1.201%), and benzo(a)pyrene (0.117%). 

VOC occurrence (also based on the Stage 1 analysis relative to the MCL concentration)

ranged from a high of tetrachloroethylene with 6.448% of the total population served by systems 

reporting at least one detection greater than the tetrachloroethylene MCL concentration to a low 

of no detections greater than the MCL concentrations for 1,2-dichlorobenzene, trans-1,2-

dichloroethylene, ethylbenzene, monochlorobenzene, 1,2,4-trichlorobenzene and total xylenes. 

The top five occurring VOCs based on this Stage 1 MCL measure are tetrachloroethylene 

(6.448%), trichloroethylene (5.264%), 1,1-dichloroethylene (2.517%), carbon tetrachloride 

(2.189%), and dichloromethane (1.298%). These population-related occurrence measures 
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(approximate measures of potential exposure) for IOCs, SOCs, and VOCs track closely with 

measures of occurrence based on the number of PWSs with at least one detection at a systemlevel, rather than population served- level measure of occurrence.

The national occurrence of four radionuclides was also assessed using the same Stage 1 

analysis that provides a preliminary estimate of potential exposure. Based on the estimated 

percent of total population served by PWSs reporting at least one detection greater than each 

contaminant’s MCL concentration, the highest occurring radionuclide is uranium (11.884%). 

Additionally, eleven SOCs and eleven VOCs were assessed using the Stage 2 analytical 

approach. The Stage 2 occurrence analyses conducted in this report, based roughly on long-term, 

multi-year average contaminant occurrence, are not the same as the occurrence analyses formally

conducted to assess compliance with contaminant drinking water standards (which for most 

contaminants are based on annual average contaminant occurrence; see Section 5.3 for details). 

Based on the population served by systems nationally with an estimated long-term mean 

contaminant concentration greater than the respective MCL concentration, the SOCs had 

occurrence as high as 0.014% (toxaphene) and as low as 0.000% (carbofuran, 2,4-

dichlorophenoxyacetic acid, endothall, hexachlorocyclopentadiene, and oxamyl). The two 

highest occurring VOCs were tetrachloroethylene with 0.277% of the population served by 

systems with a long-term mean greater than its MCL concentration, and trichloroethylene with 

0.181% of the population served by systems with a long-term mean greater than its MCL 

concentration. For three of the VOCs evaluated using the Stage 2 analysis –1,2-dichloropropane, 

1,1,2-trichloroethane, and total xylenes– no PWS nationally had an estimated long-term mean 

greater than each contaminant’s respective MCL concentration.

Background information regarding the national contaminant occurrence data and data 

management is presented in Sections 1 through 5 of this report. The summary of the Stage 1 

analytical findings is presented in Section 6, with complete, detailed Stage 1 analysis findings for 

all 65 chemical and 4 radiological contaminants included in Appendix A. The summary of the 

Stage 2 analytical findings for 22 select contaminants is presented in Section 7, with complete 

detailed Stage 2 occurrence findings for the 22 contaminants included in Appendix B. 

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Contents 

Disclaimer ...................................................................................................................................... iii

Acknowledgements ......................................................................................................................... v

Executive Summary ...................................................................................................................... vii

Contents ......................................................................................................................................... xi

1 Introduction ............................................................................................................................. 1

1.1 Purpose and Scope ................................................................................................ 2

1.2 Data Sources .......................................................................................................... 2

1.3 Data Analysis ........................................................................................................ 2

2 The National Compliance Monitoring-ICR Dataset for the Second Six-Year Review .......... 4

2.1 Completeness and Representativeness of the Six-Year Review-ICR Dataset ...... 5

3 Data Management ................................................................................................................. 11

3.1 Dataset Consistency and Restructuring ............................................................... 13

3.2 Conversion to Complete and Unique Non-Detection Records ........................... 14

3.3 Identifying and Replacing Non-Numeric or Incorrect Non-Detection Records . 15

3.4 Establishing Consistent Data Fields for Analytical Results ................................ 16

3.5 Establishing Consistent Analytical Units ............................................................ 16

3.6 Records Excluded from Analyses ....................................................................... 16

3.7 Missing System Inventory Data .......................................................................... 18

3.8 Adjustments of Population Served by Public Water Systems............................. 18

4 Data Quality Assurance/Quality Control .............................................................................. 20

4.1 Review of Dataset Content .................................................................................. 20

4.2 Data Element Completeness................................................................................ 20

4.3 Potential Outliers and Incorrect Units ................................................................. 23

5 Summary of the Compliance Monitoring Data ..................................................................... 26

5.1 Characteristics of the Data - States, Systems and Records ................................. 26

5.2 Occurrence Variability Assessment .................................................................... 33

5.3 Threshold Evaluations ......................................................................................... 35

6 Stage 1 Analysis .................................................................................................................... 36

6.1 Summary of Stage 1 Contaminant Occurrence Findings .................................... 36

6.2 Comparison of Stage 1 Analysis of First and Second Six-Year Reviews ........... 46

6.3 System Sample Point Level Analysis.................................................................. 49

7 Stage 2 Analysis .................................................................................................................... 54

7.1 Summary of Occurrence Estimations .................................................................. 55

8 Summary of Findings ............................................................................................................ 57

9 References ............................................................................................................................. 59

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Exhibits 

Exhibit 2-1. States with Compliance Monitoring Data Included in the Six-Year Review-ICR 

Dataset................................................................................................................................. 4

Exhibit 2-2. Comparison of the Total Number of Systems and Population Served by Systems in 

the Baseline Handbook (2003) and the Six-Year Review-ICR Dataset, By State 1

 ........... 8

Exhibit 2-3. Comparison of the Total Number of Systems and Population Served by Systems in 

the Baseline Handbook and the Six-Year Review-ICR Dataset, By Source Water Type 

and System Type 1

 ............................................................................................................ 10

Exhibit 3-1. Summary of Compliance Monitoring Data Provided by States for the Second SixYear Review...................................................................................................................... 11

Exhibit 3-2. Chemical Group Monitoring Requirements ............................................................. 17

Exhibit 4-1. Requested Data Elements ......................................................................................... 21

Exhibit 4-2. List of Contaminants for Which Data Were Requested from States ........................ 22

Exhibit 5-1. Number of Systems and Population Served by Systems in the Six-Year ReviewICR Dataset, by Source Water Type ................................................................................. 26

Exhibit 5-2. Number of Systems and Population Served by Systems in the Six-Year Review-ICR 

Dataset, by System Size .................................................................................................... 26

Exhibit 5-3. Number of Systems and Population Served by Systems in the Six-Year Review-ICR 

Dataset, by System Type................................................................................................... 27

Exhibit 5-4. An Inventory of Contaminant Occurrence Data in the Six-Year Review-ICR 

Dataset, by State................................................................................................................ 28

Exhibit 5-5. An Inventory of the Contaminant Occurrence Data in the Six-Year Review-ICR 

Dataset, by Contaminant ................................................................................................... 30

Exhibit 6-1. Summary of Stage 1 Contaminant Occurrence Findings – Systems and Population 

Served by Systems ............................................................................................................ 40

Exhibit 6-2. Number and Percent of Systems and Population Served by Systems with Detections 

Greater than the MCL Concentration ............................................................................... 43

Exhibit 6-3. Comparison of Stage 1 Analyses of the First Six-Year Review and the Second SixYear Review based on the Percent of Systems ................................................................. 46

Exhibit 6-4. Summary of Stage 1 Contaminant Occurrence Findings – Sample Points and 

Population Served by Sample Points ................................................................................ 51

Exhibit 7-1. Comparison of Stage 1 and Stage 2 Analytical Results - Percent of Systems and 

Population Served by Systems Greater than the MCL Concentration .............................. 55

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Appendices

APPENDIX A. Stage 1 Analysis Occurrence Measures for 65 Regulated Chemical and 4 

Radionuclide Contaminants

APPENDIX B. Stage 2 Analysis Occurrence Measures for 22 Select Regulated Chemical 

Contaminants

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Acronyms

CAS Chemical Abstracts Service

CWS Community Water System

DBCP 1,2-Dibromo-3-chloropropane

DEHA Di(2-ethylhexyl)adipate

DEHP Di(2-ethylhexyl)phthalate

EDB Ethylene dibromide

EPA Environmental Protection Agency (United States)

EQL Estimated Quantitation Level

GW Ground Water

GWUDI Ground Water Under Direct Influence (of Surface Water)

ICR Information Collection Request

IOC Inorganic Chemical

LCR Lead and Copper Rule

MCL Maximum Contaminant Level

MDL Method Detection Limit 

MFL Million Fibers per Liter

mg/L Milligrams per Liter

mrem/yr Millirem per year

MRL Minimum Reporting Level

ND Non-detect or Non-detection

NPDWR National Primary Drinking Water Regulation

NTNCWS Non-Transient Non-Community Water System
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OGWDW Office of Ground Water and Drinking Water

PCBs Polychlorinated Biphenyls

pCi/L Picocuries per Liter

PWS Public Water System

PWSID Public Water System Identification Number

QA Quality Assurance

QC Quality Control

SDWA Safe Drinking Water Act

SDWIS/Fed Safe Drinking Water Information System / Federal Version

SDWIS/State Safe Drinking Water Information System / State Version

SOC Synthetic Organic Chemical

SP Sample Point 

SW Surface Water

TCE Trichloroethylene

TCR Total Coliform Rule

TNCWS Transient Non-Community Water System

USEPA United States Environmental Protection Agency

μg/L Micrograms per Liter

VOC Volatile Organic Chemical
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1 Introduction 

Pursuant to the 1996 Safe Drinking Water Act (SDWA) Amendments, the Environmental 

Protection Agency (EPA) conducts, at least every six years, a review of the National Primary 

Drinking Water Regulations (NPDWRs). For this “Six-Year Review” of the nation’s public 

drinking water standards, EPA assesses the occurrence of regulated contaminants in public water 

systems (PWSs) in conjunction with other complementary assessments of health effects, 

analytical feasibility, and treatment feasibility. Assessments are conducted to determine if 

revisions to the existing NPDWRs (public drinking water standards) are appropriate. EPA 

completed and published the results of its first Six-Year Review of NPDWRs in July of 2003 (68 

FR 42908, USEPA, 2003a) after developing a systematic approach, or protocol, for the review. 

EPA has applied the same protocol with minor refinements to the current, second Six-Year 

Review of NPDWRs (“Six-Year Review 2”). This report presents the assessments of national 

contaminant occurrence in PWSs in the United States in support of EPA’s second Six-Year 

Review of NPDWRs.

Because there exists no national database of regulated drinking water contaminant 

occurrence data for public drinking water systems, EPA conducted a voluntary data call-in from 

the states, territories, and tribes to obtain the data using the Information Collection Request 

(ICR) process. EPA worked with states and primacy agencies to receive their complete 

compliance monitoring data for 1998 through 2005, and state data management staff were 

consulted to resolve any questions about the data submitted. EPA conducted data management 

and quality assurance (QA) evaluations to establish a high quality, national contaminant 

occurrence database consisting of data from 47 states/primacy agencies (45 states plus Region 8 

and Region 9 tribes). This dataset, referred to as the National Compliance Monitoring ICR 

Dataset for the Second Six-Year Review (or “Six-Year Review-ICR Dataset”), is the largest and 

most comprehensive compliance monitoring dataset ever compiled and analyzed by EPA’s 

Drinking Water Program. Using this dataset, EPA employed a two-stage analytical approach to 

estimate a variety of occurrence measures to characterize the national occurrence of regulated 

contaminants in systems to support the Six-Year Review process.

This report describes the extensive data management and data quality checks conducted 

as part of the development of the Six-Year Review-ICR Dataset, explains the analytical approach 

used to estimate the various measures of national contaminant occurrence, and presents and 

describes the resulting national contaminant occurrence estimates. This report presents many 

different measures and estimates of national occurrence. Some of the contaminant occurrence 

measures are presented in this report as “preliminary exposure estimates.” This means that they 

are not formal exposure estimates, but estimates of the population served by systems found to 

have some degree of contaminant occurrence in their drinking water samples. In addition to this 

report, there are also two accompanying reports that present a shorter summary of contaminant 

occurrence and preliminary exposure estimates as well as important background information on 

each contaminant reviewed (USEPA, 2009a and b).
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1.1 Purpose and Scope

EPA’s Office of Ground Water and Drinking Water (OGWDW) is responsible for 

implementing the provisions of SDWA. Under SDWA, OGWDW develops regulations to 

address the public health risks from contaminated drinking water and develops related programs 

to protect ground water (GW) and surface water (SW) supplies. The 1996 Amendments to 

SDWA require that EPA shall, at least once every six years, review and revise, as appropriate, 

each NPDWR promulgated by the Agency. SDWA specifies that revision of a NPDWR shall 

maintain or provide for greater protection of public health. Any revision of the regulations will 

be partially dependent on contaminant occurrence findings, and on the reevaluation of the 

public’s exposure to the contaminants and the potential adverse health effects from that 

exposure. The purpose of this report is to describe the contaminant occurrence data, data 

management, and statistical methods used to develop the national contaminant occurrence 

estimations in support of EPA’s second Six-Year Review.

1.2 Data Sources

To estimate national occurrence of regulated contaminants in PWSs, it is necessary to 

have all contaminant occurrence sample results including all sample analytical detections and

non-detections (NDs). The Federal Safe Drinking Water Information System database 

(SDWIS/Fed) contains complete maximum contaminant level (MCL) violation data; however, 

SDWIS/Fed does not receive or store complete compliance monitoring (parametric) records. 

These data are collected by states and primacy agencies but are not required to be submitted to 

SDWIS/Fed. Therefore, to obtain the necessary compliance monitoring parametric data to 

support national occurrence assessments for the second Six-Year Review, EPA conducted a 

voluntary data call-in from the states and primacy agencies. This data call-in was conducted 

through the ICR process. The second Six-Year Review ICR document (USEPA, 2006) describes 

the process undertaken to request the voluntary submission of compliance monitoring data by the 

states.

Through the ICR process, EPA requested that states and primacy agencies voluntarily 

submit their SDWA compliance monitoring data including all parametric data with complete 

records of all sample detections and non-detections collected between January 1998 and 

December 2005. Forty-six states and five other primacy agencies provided compliance 

monitoring data that included parametric records. Through extensive data management efforts

and quality assurance evaluations as well as communications and consultations with state data 

management staffs, EPA established a high quality contaminant occurrence dataset (the Six-Year 

Review-ICR Dataset) that consists of data from 47 states/primacy agencies (45 states plus 

Region 8 and Region 9 tribes). Data received from one state and three primacy agencies could 

not be included in the second Six-Year data analyses. See Section 2 for details on states included 

in the Six-Year Review-ICR Dataset.

1.3 Data Analysis

EPA used a two-stage analytical approach to estimate the national contaminant 

occurrence using the Six-Year Review-ICR Dataset. The first stage of analysis provides a 

simple, straightforward evaluation of occurrence of all contaminants. The “Stage 1 analysis” of 

occurrence assesses the data sources, quality, and characteristics, and then uses the data to 
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generate summary statistics of each contaminant’s occurrence as well as national estimates of 

occurrence that are simple, non-parametric, and conservative.1 Occurrence analyses for each 

contaminant are conducted for samples, systems, population served by systems, and system 

sample point (SP) locations. A typical Stage 1 analysis is a simple count of the number or 

percentage of systems reporting at least one sample detection of a specific contaminant, or at 

least one sample detection with a concentration greater than the MCL value of the contaminant.

The details of the Stage 1 analysis methods are described in Section 6. 

Based on the findings of the Stage 1 analysis, EPA selected a set of contaminants for 

which additional parametric statistical estimations were warranted (referred to as “Stage 2 

analyses”). The Stage 2 analysis estimates national contaminant occurrence by generating 

estimated long-term mean concentrations of contaminants for each system. This provides 

occurrence analyses that are less conservative than the Stage 1 analysis, since the Stage 2 

analysis is based on estimated mean concentrations rather than on a single maximum 

concentration. Also, because the Stage 2 analyses generate long-term (multi-year) mean 

concentration estimates for contaminant occurrence at systems, the analyses can support 

assessments of population served by systems with detections or “preliminary exposure” 

assessments that may be more reflective of potential chronic exposure than the assessments from 

the Stage 1 analyses. Section 7 describes the details of the Stage 2 analysis.

The Stage 1 analysis reflects a rough approximation of peak occurrence while the Stage 2 

analysis is based on estimated long-term average occurrence. This fundamental difference 

between the two analytical approaches has a very direct implication: regardless of the 

contaminant concentration value assessed, the Stage 1 analysis findings will always exceed, or in 

some cases be approximately equal to, the Stage 2 analysis findings. For example, the Stage 1 

analysis of the number of systems with at least one detection of benzene greater than the MCL 

concentration will always be greater than, or perhaps equal to, the Stage 2 analysis showing the 

number of systems with a mean concentration of benzene greater than the MCL concentration. 

This two-stage analytical approach was previously developed for other EPA OGWDW 

national occurrence studies, including those conducted for the first Six-Year Review of 

NPDWRs (USEPA, 2003b) and the first and second Regulatory Determinations for 

Contaminants from the Drinking Water Contaminant Candidate List (USEPA, 2002, 2008a, and 

2008b). The overall data management and general two-stage occurrence analytical approach used 

for these OGWDW projects was peer-reviewed for use under the first Six-Year Review, which 

assessed regulated contaminant occurrence data collected from 1993 to 1997. The Stage 2 

analysis used for this second Six-Year Review has been simplified from the Stage 2 analysis 

used for the first Six-Year Review. This was possible because a significantly larger number of 

states provided contaminant occurrence data for the second Six-Year Review. See Section 7 for a 

description of the new Stage 2 analysis. 

1 The Stage 1 analyses are conservative in the sense that they are protective of human health (i.e., because they are 

based on a single, maximum sample detection value rather than an average value for each system, the Stage 1 

analyses are more likely to overestimate occurrence and potential risks to human health than underestimate them).
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2 The National Compliance Monitoring-ICR Dataset for

the Second Six-Year Review

Through the ICR process, EPA conducted a voluntary data call-in for states’ compliance 

monitoring records and received data from a total of 51 states/primacy agencies: 46 states;

American Samoa; Washington, D.C.; Region 8 tribes; Region 9 tribes, and the Navajo Nation.

Through extensive data management efforts, quality assurance evaluations, and communications 

with state data management staff, EPA established the Six-Year Review-ICR Dataset. This high 

quality, national contaminant occurrence database consists of data from 45 states and 2 primacy 

agencies (see Exhibit 2-1 below). The data received from American Samoa, Washington, D.C., 

and the Navajo Nation was not included in the second Six-Year data analyses because those 

datasets were in significantly different formats that would require excessive effort to transform.

The data from Kansas were received after the data assessment and quality assurance measures 

were completed and were not included in this occurrence analysis.

Exhibit 2-1. States with Compliance Monitoring Data Included 

in the Six-Year Review-ICR Dataset

The compliance monitoring contaminant occurrence data from these 47 states/primacy 

agencies comprise more than 15 million analytical records from approximately 132,000 systems.

Approximately 254 million people are served by these systems nationally.
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Data quality, completeness, and representativeness are key considerations for the dataset. 

Given the size, scope, and variety of formats of the datasets received from the states, EPA 

conducted extensive data management and quality assurance/quality control (QA/QC) 

assessments on the data to be included in the Six-Year Review-ICR Dataset. A review of 

completeness and representativeness is presented later in this section, with other details of data 

management and quality assessments presented in the following three sections.

2.1 Completeness and Representativeness of the Six-Year Review-ICR

Dataset

The final Six-Year Review-ICR Dataset consists of compliance monitoring data received 

from 47 out of 59 states/primacy agencies representing a very large sample and the largest 

compliance monitoring dataset ever compiled and analyzed by EPA’s Drinking Water Program. 

The 45 states that provided data for the Six-Year Review-ICR Dataset comprise 88% of all 

public drinking water systems and 89% of the total population served by PWSs nationally, and 

represent all regions nationally.2 The states not included in the Six-Year Review-ICR Dataset 

(see Exhibit 2-1) represent approximately 12% of systems and 11% of the population served by 

systems nationally. These five states are geographically distributed across the United States and 

reflect a diverse mix of urban, agricultural, and industrial areas. The five states not providing 

compliance monitoring contaminant occurrence data are not clustered in a single region so no 

regional geologic terrain, climatic or hydrologic zone, geography, or socio-economic activity is 

unrepresented in the dataset. Although two neighboring states on the Gulf Coast, Louisiana and 

Mississippi, did not provide data, the three other Gulf Coast states did provide data, allowing for 

significant regional coverage, especially from a population-based perspective. The Six-Year 

Review-ICR Dataset, with 45 of the 50 states represented, is therefore considered reasonably 

complete and nationally representative as the basis of the contaminant occurrence estimates

presented in this report.

The absence of data from five states in the final Six-Year Review-ICR Dataset could 

potentially bias how well this dataset represents the national occurrence of particular 

contaminants. However, in a general sense, the five states, representing about 11% of PWSs and 

population served by PWSs nationally, have a fairly small influence relative to a national 

aggregate occurrence rate based on 45 states, representing about 89% of the PWSs and 

population served by PWSs nationally. To address the issue of potential bias, though, EPA 

conducted an assessment for each contaminant by comparing occurrence in the 5 states to that in 

the 45 states.

Because a complete compliance monitoring dataset of all 50 states does not exist, it is not 

possible to know the true national occurrence for a particular contaminant or how occurrence 

rates for a particular contaminant in the 5 missing states compare to occurrence in the other 45 

states. Therefore, an indicator of occurrence was developed using data available from the 

SDWIS/Fed database. EPA compiled SDWIS/Fed records of MCL violations by state for the 

2 This completeness assessment focuses on the 50 states and does not include the primacy entities (territories and 

tribes), given the total population-served by PWSs in the states as compared to the primacy entities.
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same years (1998-2005) as the Six-Year Review-ICR Dataset.3 The MCL violation records were 

used to determine if the violation rate, the indicator of contaminant occurrence, in the five 

missing states was greater than, less than, or about the same as the violation rate in the 45 states 

in the dataset. This assessment was conducted for all individual contaminants.

The mean MCL violation rate, the percentage of systems with at least one MCL violation,

for each contaminant was calculated in aggregate for the 45 states in the dataset and separately in 

aggregate for the 5 states not in the Six Year Review-ICR Dataset. For each contaminant, these 

two estimated means (45 state vs. 5 state) were compared with a simple statistical t-test to 

determine if the mean MCL violation rate for the 5 missing states was significantly different 

from the mean MCL violation rate for the 45 states.4

Of the 69 contaminants evaluated, 58 had no significant difference in MCL violation 

rates between the 5-state and the 45-state groups. For four contaminants – arsenic, nitrate, 

tetrachloroethylene, and trichloroethylene – the MCL violation rate for the five missing states 

was statistically determined to be higher than the rate for the 45 states in the dataset. This finding 

suggests that the absence of system compliance monitoring data from the five states might result 

in some slight amount of under-estimation of occurrence for those four contaminants. For seven 

contaminants; fluoride, asbestos, di(2-ethylhexyl)phthalate (DEHP), 1,2-dibromo-3-

chloropropane (DBCP), alpha particles, uranium, and combined radium-226/228, the MCL 

violation rate for the five missing states was statistically determined to be lower than the rate for 

the 45 states in the dataset. This suggests that the absence of system compliance monitoring data 

from the five states might result in some slight amount of over-estimation of occurrence for those 

seven contaminants. These findings are most appropriately used as context or background for the 

quantitative occurrence findings presented in Sections 6 and 7 of this report.

To further evaluate the completeness of each state’s dataset, EPA compared the number 

of systems in each state’s submitted Six-Year Review-ICR data to the number of systems listed 

as operating in each state according to the latest edition of the Drinking Water Baseline 

Handbook (USEPA, 2003c). The “Baseline Handbook” is a standard source for national PWS 

inventory information (Exhibits 2-2 and 2-3). These comparisons indicate that the data in the 

Six-Year Review-ICR Dataset are reasonably complete. Because of differences between the 

system inventory information contained in the Baseline Handbook versus that in the Six Year 

Review-ICR Dataset, this completeness assessment is more general than specific.

The system inventory information represented in the two data sources is quite similar 

though not equivalent. The main difference is that the Six-Year Review-ICR Dataset reflects the 

total number of systems with compliance monitoring data in any of the eight years represented in 

the dataset (1998-2005), while the Baseline Handbook numbers reflect the number of systems in 

a single year (2002). Since systems open, close, and consolidate over time, the number of 

3 While the SDWIS/Fed database does not store complete compliance monitoring parametric records, the database 

does maintain the most current and complete national and state records of contaminant MCL violations. Annual 

MCL data were downloaded from http://www.epa.gov/safewater/data/pivottables.html.

4 The t-test calculation used considered the variance, mean, and sample size of each of the two groups of states to 

estimate the probability that the observed difference in sample means represents an actual difference in contaminant 

occurrence and not just a statistical inconsistency resulting from low sample sizes.
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systems in each state will understandably be somewhat different between the two data sources.

Population changes in system service areas over time could also contribute to differences in 

population served numbers for systems between the two data sources. Also, the numbers 

presented for the Baseline Handbook do not include tribal water systems and the Six-Year 

Review-ICR Dataset includes data for Region 8 and Region 9 tribes. In addition, the Baseline 

Handbook numbers include both “purchased systems” (systems that purchase 100% of their 

water) and “non-purchased systems” (systems that self-source water and/or buy less than 100% 

of their water) while the Six-Year Review-ICR Dataset excludes systems that purchase 100% of 

their water. Purchased systems do not have the same compliance monitoring requirements as 

other systems so the purchased systems were excluded from these occurrence analyses.

However, because their populations are at risk of exposure to a contaminant, EPA adjusted the 

population served numbers for the state datasets to account for populations that are served by 

purchased systems. These adjusted population served values should approximately equal the raw, 

unadjusted population served values for all purchased and non-purchased systems in the Baseline 

Handbook.5 Therefore, only general comparisons can be made. Nonetheless, the system and 

population served values from both sources of data compare fairly well; it appears that the states

provided essentially all compliance monitoring records as specified in the Six-Year Review-ICR 

data request, and the comparison suggests that the Six-Year Review-ICR Dataset is essentially 

complete.

Overall, for the 45 states in the dataset there is an approximately 0.1% difference between 

the number of systems listed in the Baseline Handbook compared to the number of systems in 

the data submitted by the 45 states for the second Six-Year Review (Exhibit 2-2). Comparing the 

number of systems for each state, the percentage difference between the Baseline Handbook and 

the Six-Year Review-ICR data ranges from less than 1% difference (e.g., Oklahoma and Rhode 

Island) to almost a 50% difference (e.g., Montana and Virginia) in the number of systems. Based 

on the population served by systems, for the overall national 45-state total , there is a 1.8% 

difference between the total population-served by systems listed in the Baseline Handbook 

compared to the population served by systems in the data submitted by the 45 states for the 

second Six-Year Review. Comparing individual state population served values, the percentage 

differences between the Baseline Handbook and the Six-Year states ranges from less than a 1% 

difference (e.g., Arkansas and West Virginia) to approximately a 50% difference (e.g., Nevada). 

In communications with states’ data management staff, several mentioned that population growth 

in the Southwestern United States probably accounts for some of the population differences 

between the Baseline Handbook estimates (from 2003 and earlier) to the estimates from the SixYear Review-ICR Dataset (with most system population information from 2005). Also, in 

Nevada, for the population adjustments made regarding purchased systems, it was not possible to 

determine seller-purchaser links for a single very large system serving about 1 million people. 

Therefore, the Nevada population served total for the Six-Year Review-ICR data are 

approximately 1 million less that the number presented in the Baseline Handbook. See Section 

3.8 for details of the population adjustments and seller-purchaser links.

5 The adjusted population-served values reflect the addition of the population-served by systems that purchase 100%

of their water because the population-served by those 100% purchasing systems would otherwise be excluded from 

the Six-Year Review analyses. Details on this adjustment are presented in Section 3.8.
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Exhibit 2-2. Comparison of the Total Number of Systems and Population Served

by Systems in the Baseline Handbook (2003) and the Six-Year Review-ICR 

Dataset, By State 1

State

Total Number of Systems2 Total Population Served by All Systems

Baseline 

Handbook3

Six-Year 

Review-ICR 

Data

Percent 

Difference

Baseline 

Handbook3,4

Six-Year 

Review-ICR 

Data5

Percent 

Difference

Alabama 433 425 1.8% 5,140,563 4,741,994 7.8%

Alaska 1,516 1,477 2.6% 597,332 712,666 -19.3%

Arizona 1,594 1,663 -4.3% 4,991,548 6,292,843 -26.1%

Arkansas 776 456 41.2% 2,469,902 2,453,733 0.7%

California 5,710 7,605 -33.2% 32,654,400 38,646,745 -18.4%

Colorado 1,922 1,748 9.1% 5,753,222 5,259,232 8.6%

Connecticut 3,016 2,918 3.2% 2,862,278 2,787,413 2.6%

Delaware 555 580 -4.5% 894,435 778,333 13.0%

Florida 6,327 6,261 1.0% 16,699,708 18,939,279 -13.4%

Georgia 2,411 1,931 19.9% 7,215,332 7,500,353 -4.0%

Hawaii 112 116 -3.6% 1,292,059 1,310,187 -1.4%

Idaho 2,032 1,955 3.8% 1,074,492 1,206,368 -12.3%

Illinois 4,675 3,957 15.4% 11,770,883 9,630,392 18.2%

Indiana 4,235 5,338 -26.0% 5,065,608 5,492,975 -8.4%

Iowa 1,750 1,899 -8.5% 2,626,823 2,653,189 -1.0%

Kentucky 449 298 33.6% 4,469,109 4,619,135 -3.4%

Maine 1,980 2,257 -14.0% 887,053 950,371 -7.1%

Maryland 3,742 4,105 -9.7% 4,759,189 5,279,878 -10.9%

Massachusetts 1,502 1,697 -13.0% 7,122,088 8,738,481 -22.7%

Michigan 11,900 14,521 -22.0% 8,957,282 8,850,281 1.2%

Minnesota 7,869 9,408 -19.6% 4,557,788 4,898,639 -7.5%

Missouri 2,473 2,691 -8.8% 5,035,937 4,976,894 1.2%

Montana 1,830 1,014 44.6% 911,871 786,930 13.7%

Nebraska 1,225 792 35.3% 1,528,468 1,469,627 3.8%

Nevada6 595 577 3.0% 1,981,791 998,101 49.6%

New Hampshire 2,143 2,643 -23.3% 1,090,766 1,282,866 -17.6%

New Jersey 4,046 4,221 -4.3% 8,431,376 8,258,339 2.1%

New Mexico 1,246 885 29.0% 1,807,797 1,735,210 4.0%

New York 9,340 6,677 28.5% 18,925,806 14,827,610 21.7%

North Carolina 7,213 6,559 9.1% 6,809,879 7,351,966 -8.0%

North Dakota 392 218 44.4% 570,872 563,112 1.4%

Ohio 5,373 5,078 5.5% 10,840,585 10,691,928 1.4%

Oklahoma 1,043 1,036 0.7% 3,476,517 3,173,290 8.7%

Oregon 2,625 2,672 -1.8% 3,132,622 3,182,082 -1.6%

Rhode Island 468 470 -0.4% 1,350,943 968,684 28.3%

South Carolina 1,290 1,650 -27.9% 3,413,847 3,777,736 -10.7%

South Dakota 521 432 17.1% 688,061 676,911 1.6%

Tennessee 841 369 56.1% 5,422,136 5,686,766 -4.9%

Texas 5,670 6,453 -13.8% 22,385,504 25,418,822 -13.6%

Utah 859 999 -16.3% 3,813,258 2,638,287 30.8%

Vermont 1,368 1,317 3.7% 647,415 596,375 7.9%
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State

Total Number of Systems2 Total Population Served by All Systems

Baseline 

Handbook3

Six-Year 

Review-ICR 

Data

Percent 

Difference

Baseline 

Handbook3,4

Six-Year 

Review-ICR 

Data5

Percent 

Difference

Virginia 3,369 1,820 46.0% 8,495,323 6,245,276 26.5%

West Virginia 1,066 1,123 -5.3% 1,502,322 1,503,712 -0.1%

Wisconsin 11,455 7,013 38.8% 4,665,249 4,719,892 -1.2%

Wyoming 681 636 6.6% 527,201 521,508 1.1%

Total 131,638 127,960 0.1% 249,316,640 253,794,411 -1.8%

1. The number of systems and population served by tribal water systems in Regions 8 and 9 are not included in the 

Baseline Handbook numbers in this table.

2. As indicated in Exhibit 5-3, approximately 58% of the total number of water systems whose data were submitted by 

states for the second Six-Year Review are transient non-community water systems. Because only the nitrate/nitrite 

regulations require compliance monitoring by these transient systems (see Exhibit 3-2), data from the transient 

systems were included only for the nitrate and nitrite occurrence analyses and were excluded for all occurrence 

analyses for inorganic chemicals (IOCs), synthetic organic chemicals (SOCs), volatile organic chemicals (VOCs), and 

radiological contaminants. The tables in Appendix A present the total number of community plus non-transient noncommunity water systems included in the occurrence analyses for each state for all IOCs, SOCs, VOCs, the total 

number of community plus non-transient non-community plus transient non-community water systems for nitrate and 

nitrite, and the total number of community water systems for radionuclides.

3. The source of these data is the Drinking Water Baseline Handbook, Fourth edition (USEPA, 2003c).

4. The Baseline Handbook population numbers in this column represent the population served by purchased and

non-purchased systems.

5. The Six-Year Review-ICR data population numbers in this column represent the adjusted wholesale/retail 

population served by all non-purchased systems. See Section 3.8 for details on the population adjustments.

6. For the population adjustments made regarding purchased systems, it was not possible to determine sellerpurchaser links for a single very large system in Nevada serving about 1 million people. Therefore, the Nevada 

population served total for the Six-Year Review-ICR data are approximately 1 million less that the number presented 

in the Baseline Handbook. See Section 3.8 regarding population adjustments and seller-purchaser links.

Exhibit 2-3 compares the number of non-purchased systems and population served by 

these systems in the Baseline Handbook and the Six-Year Review-ICR Dataset stratified by 

source water type and system type. The overall national 45-state totals indicate about 0.1% less 

systems and a 1.8% more population served in the Six-Year Review-ICR Dataset than is 

represented in the Baseline Handbook. For community water systems (CWSs), there is about a 

2% difference based on the number of systems and a 2% difference based on the population 

served by systems. Percentage differences were larger for ground water systems than surface 

water systems. For non-transient non-community water systems (NTNCWSs), there is about a 

14% difference based on the number of systems and a 10% difference based on the population 

served by systems. For transient non-community water systems (TNCWSs), there is about a 4% 

difference based on the number of systems and a 10% difference based on the population served

by systems. CWSs account for approximately 94% of the total population served by systems in 

the United States.
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Exhibit 2-3. Comparison of the Total Number of Systems and Population Served by Systems in the Baseline 

Handbook and the Six-Year Review-ICR Dataset, By Source Water Type and System Type 1

Source 

Water Type

Community 

Water Systems (CWS)

Non-Transient 

Non-Community 

Water Systems

(NCNCWS)

Transient 

Non-Community 

Water Systems (TNCWS)

Unknown System Type 2 Total

Baseline

Handbook

Six-Year 

Review-ICR 

Data

Baseline 

Handbook

Six-Year 

Review-ICR 

Data

Baseline 

Handbook

Six-Year 

Review-ICR 

Data

Baseline 

Handbook

Six-Year 

Review-ICR 

Data

Baseline 

Handbook

Six-Year 

Review-ICR 

Data

Number of Non-Purchased Systems

Ground Water (GW) 32,343 33,080 15,809 18,002 77,658 74,690 0 307 125,810 126,079Surface Water (SW) 4,215 4,134 327 319 1,286 1,011 0 7 5,828 5,471Total 36,558 37,214 16,136 18,321 78,944 75,701 0 314 131,638 131,550

Total Population Served 3

Ground Water (GW) 72,377,555 85,195,608 4,432,931 4,931,440 10,891,422 9,946,745 0 22,122 87,701,908 100,095,915Surface Water (SW) 160,485,186 152,805,883 419,062 398,629 710,484 492,774 0 1,210 161,614,732 153,698,496Total 232,862,741 238,001,491 4,851,993 5,330,069 11,601,906 10,439,519 0 23,332 249,316,640 253,794,4111. The number of systems and population served by tribal water systems in Regions 8 and 9 are not included in the Baseline Handbook numbers in this table.

2. Systems with unknown system type (i.e., no system type was specified in the data) were included in the second Six-Year Review analyses. None of the occurrence analyses conducted for the second Six-Year Review required specifying the system type.3. The Baseline Handbook population numbers represent the population served by purchased and non-purchased systems. The Six-Year Review-ICR data populationnumbers represent the adjusted wholesale/retail population served by all non-purchased systems. See Section 3.8 for details on the population adjustments.
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3 Data Management

The data received from the states and primacy agencies were in a variety of formats and 

data structures, and required reformatting to an exact uniform structure to enable the national 

contaminant occurrence analyses. This section provides an overview of the data management 

efforts that were conducted to enable and facilitate the contaminant occurrence analyses. Details 

of the data management measures can be found in the report titled “The Data Management and 

Quality Assurance/Quality Control Process Used to Edit the State Compliance Monitoring 

Datasets Submitted for the Six-Year Review” (Cadmus, 2008).

More than half of all states currently store and manage at least portions of their 

compliance monitoring data in the Safe Drinking Water Information System/State Version 

(SDWIS/State). The majority of states using SDWIS/State that submitted data to EPA used a 

SDWIS Query Extract Tool, developed and provided by EPA, to extract and compile the 

compliance monitoring data requested by EPA. (Only two states that use SDWIS/State did not 

use the SDWIS Query Extract Tool to compile the requested data. These states submitted their 

data to EPA for use in the Six-Year Review before the SDWIS Query Extract Tool was available 

to the states.) The Extract Tool enabled a streamlined effort by states to select, compile, and 

format the requested data, and generally resulted in state submission of complete datasets that 

were uniform in format. The states not using SDWIS/State submitted their compliance 

monitoring data “as is,” resulting in a variety of formats of datasets submitted to EPA.

Exhibit 3-1 summarizes the types of files, SDWIS/State status, use of the extract tool, and 

date range of the data provided by states. Note that SDWIS/State status is based on status at the 

time the voluntary data call-in was conducted and does not reflect subsequent changes in status.

Exhibit 3-1. Summary of Compliance Monitoring Data Provided by States for the

Second Six-Year Review

State/Tribe File Type SDWIS/

State User

SDWIS

Extract Tool Date Range

Alabama Access Yes Yes 1/5/1998 - 12/30/2005

Alaska Access Yes Yes 1/5/1998 - 12/31/2005

Arizona Access Yes Yes 1/1/1998 - 12/31/2005

Arkansas Access Yes No 1/1/1998 - 12/31/2005

California dBase No N/A 1/1995 - 4/2007

Colorado Access Yes Yes 1/1/1998 - 12/30/2005

Connecticut Access Yes Yes 1/1/2002 - 12/31/2005

Delaware Access Yes Yes

10/22/1998 - 12/28/2005 (IOCs) 

9/13/2000 - 12/28/2005 (VOCs) 

1/1/2001 - 12/28/2005 (SOCs)1

Florida Excel No N/A 1/2/2004 - 12/31/2005

Georgia Access Yes Yes 3/10/1998 - 12/31/2005
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State/Tribe File Type SDWIS/

State User

SDWIS

Extract Tool Date Range

Hawaii Excel No N/A 1/3/2000 - 12/15/2005

Idaho Access Yes Yes 1/1/1998 - 12/31/2005

Illinois Access (CWS); 

Excel (NTNC) Yes No 1/5/1998 - 12/31/2005

Indiana Access Yes Yes 1/1/1998 - 12/31/2005

Iowa Access Yes Yes 1/1/1998 - 12/31/2005

Kentucky Access Yes Yes 1/2/1998 - 12/30/2005

Maine Access Yes Yes 1/5/1998 - 12/31/2005

Maryland Excel No N/A 1/1/1998 - 12/31/2005

Massachusetts Access No N/A 1/2/1998 - 12/30/2005

Michigan Comma delimited No N/A 1/1/1998 - 12/31/2005

Minnesota Text No N/A 1/1/1998 - 12/29/2005

Missouri Access Yes Yes 1/1/1998 - 12/31/2005

Montana Access Yes Yes 1/5/1998 - 12/31/2005

Nebraska Access Yes Yes 1/1/1998 - 12/31/2005

Nevada Access Yes Yes 1/1/1998 - 12/31/2005

New Hampshire Comma delimited No N/A 4/1/1998 - 10/31/2005

New Jersey Access Yes Yes 1/2/1998 - 12/30/2005

New Mexico Access Yes Yes 1/5/1998 - 12/31/2005

New York Access Yes Yes 1/5/1998 - 12/31/2005

North Carolina Oracle No N/A 1/1/1998 - 12/31/2005

North Dakota Access Yes Yes 1/1/1998 - 12/31/2005

Ohio Access Yes Yes 1/5/1998 - 12/31/2005

Oklahoma Access Yes Yes 1/2/1998 - 12/30/2005

Oregon Access Yes Yes 4/8/1998 - 12/31/2005

Region 8 tribes Access Yes Yes 1/5/1998 - 12/31/2005

Region 9 tribes Access No N/A 1/5/1998 - 12/30/2005

Rhode Island Access Yes Yes 1/5/1998 - 12/30/2005

South Carolina Access Yes Yes 1/1/2001 - 12/31/2005

South Dakota dBase No N/A 1/26/1993 - 2/26/2007

Tennessee Excel No N/A 1/5/1998 - 12/30/2005

Texas Text No No 1/2/1998 - 12/31/2005

Utah Text Yes Yes 1/5/1998 - 12/30/2005

Vermont Access Yes Yes 1/4/1998 - 12/30/2005
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State/Tribe File Type SDWIS/

State User

SDWIS

Extract Tool Date Range

Virginia Access Yes Yes 1/3/1998 - 12/31/2005

West Virginia Access Yes Yes 1/5/1998 - 12/31/2005

Wisconsin Tab delimited No N/A 1/2/1998 - 6/8/2007

Wyoming Access Yes Yes 1/1/1998 - 12/30/2005

1. Inorganic chemicals (IOCs), volatile organic chemicals (VOCs) and synthetic organic chemicals (SOCs).

3.1 Dataset Consistency and Restructuring

Upon receipt of each state dataset, a state-specific directory was created to contain the 

raw data. The original dataset was saved and maintained exactly as received. All subsequent 

changes were made and saved to a copy of the original dataset and each change was documented.

Status documentation for each state was maintained and periodically sent to EPA. The 

status update documented and described the datasets received to date, as well as the date 

received, file type, whether or not the SDWIS Query Extract Tool was used, and the date range 

of the data. The status update also described any current or ongoing state-specific notes, issues or 

concerns.

Thirty-one states and one tribe used the SDWIS Query Extract Tool to extract all or some 

of their chemical data; therefore, those datasets were all submitted in a similar format. States that 

did not use the SDWIS Query Extract Tool were restructured into a format similar to the data 

structure of the SDWIS Query Extract Tool. Some notable exceptions were a few states that 

compiled and sent one portion of their data using the SDWIS Query Extract Tool and the 

remainder of their data in another structure (for example, South Carolina). The data submitted by 

these states required extensive QA/QC and formatting effort to prepare for analyses because the 

multiple data structures for a single state’s dataset had to be separately formatted and then 

combined.

The SDWIS Query Tool extracts the SDWIS/State data into Microsoft Access. The 15 

states that did not use the SDWIS Query Extract Tool submitted data in a variety of formats, 

including dBase, Oracle, Microsoft Access, comma delimited, tab delimited, Text, and Excel. All 

of these datasets were converted to Microsoft Access to enable a detailed QA/QC review.

For the 15 states and one tribe for which the SDWIS Query Extract Tool was not used or 

was not applicable, the datasets were converted to similar formats and data structure to facilitate 

data management and analysis. In all cases, the converted datasets were compared to the original 

datasets to ensure all data were converted accurately. A few states submitted their data in several 

different files that were in different structures or software (California, Illinois, Maryland, 

Michigan, South Carolina, South Dakota, and Texas). These states submitted datasets that were 

divided or organized by chemical group, date range, system type, or by some other system 

reflecting multiple data management schemes within the particular state. The multiple structures 

for each of these states’ datasets had to be separately formatted and then combined.
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3.2 Conversion to Complete and Unique Non-Detection Records

To conduct contaminant occurrence estimates, each contaminant sample record must 

have an analytical result, whether that sample result is a detection (sample analytical result 

greater than or equal to the minimum reporting level (MRL)) or a non-detection. Sample records 

reported as non-detects tend to be less uniform and less complete than sample records for 

detections. Of the 47 states/primacy agencies that submitted compliance monitoring data for the 

second Six-Year Review, only 33 submitted at least some records that were explicitly labeled as 

MRL data. See Section 3.3 for additional details on MRLs. Approximately 70% of the system 

sample records submitted by those 33 states included explicitly labeled MRL information. Some 

systems in a particular state might report all MRL data while other systems in the same state 

might report only partial or no MRL data. 

EPA replaced any missing non-detect results with the most common modal MRL value 

for the state in which the system was located. In some cases, though, all MRL data for a specific 

contaminant’s data from an entire state were missing. In these cases, the missing values were 

replaced with the national modal MRL derived as the mode of all the state modal MRL values 

for that contaminant.

Several states submitted datasets with incomplete sample non-detect records due to 

aggregated or summarized non-detection results for multi-analyte laboratory methods. Records 

contained a single “0” or “ND” for all contaminants not detected and individual, unique numeric 

detection records only for those contaminants with a positive result. Special processing was 

required to establish complete non-detect records for all contaminants analyzed with the multianalyte method. For example, one specific EPA-certified laboratory method can analyze for 21 

different volatile organic chemicals (VOCs). If none of the 21 VOCs is detected, these states 

simply enter a single code such as “21 VOCs” in the contaminant identification field and a “0” or 

“ND” in the results field. In these cases, the single reported non-detection record was expanded 

to 21 separate records each with the appropriate unique contaminant identification code and each 

record was given a “<MRL” (non-detection) result. 

If one or more of the 21 VOCs were detected, the individual detected contaminant was 

entered in the contaminant identification field and the concentration detected was entered in the 

analytical results field as an individual observation, but the remaining VOCs with non-detections 

were again aggregated into a single record with a “0” or “ND” result. To address this, the 

specific contaminants with non-detects had to be identified. A separate record and unique 

contaminant identification code for each was established, and each record was given a “<MRL” 

or non-detection result.
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3.3 Identifying and Replacing Non-Numeric or Incorrect Non-Detection 

Records

The MRL is defined as the lowest concentration value that can be reliably achieved 

within specified limits of precision and accuracy under routine laboratory operating conditions.6

For the states that did report MRL data for systems, some recorded it in the analytical result field 

and also included a “<” in a corresponding field to identify the record as a non-detection. Other 

states simply included a zero or negative result in the analytical result field to signify a nondetection.

The Six-Year Review Stage 1 non-parametric analyses are not affected by how nondetections are recorded. However, to estimate mean contaminant concentration values for each 

system in the Stage 2 analyses, a non-zero MRL numeric value must replace all analytical results 

that were reported either as zero, “non-detection,” “ND,” etc.

Similar to replacing missing MRL data above, a convention was developed to replace any 

non-numeric non-detection results from a particular system using the modal MRL value for the 

state in which the system was located. If a state reported no MRL data, the non-numeric values 

were replaced with the national modal MRL, derived as the mode of all state modal MRL values 

reported for that contaminant.

EPA used similar data management measures when states reported MRL values that were 

extremely low or high. A process was developed for identifying and replacing such values with 

more reasonable MRL values. Reported MRL values that were below the minimum Method 

Detection Limit (MDL)7 or greater than the national modal MRL or missing were replaced with 

the national modal MRL.8

6 In other words, the MRL is the lowest contaminant concentration that can be dependably quantified in the 

laboratory and reported in the contaminant occurrence data used for analyses. Contaminant sample records reported 

as “<MRL”, therefore, reflect contaminants that are either truly absent in a sample or that occur in a sample at a

concentration value below the MRL. Sample analytical results reported as “<MRL” are often referred to as “nondetections” since the contaminant has not been detected at concentrations at or above the MRL. 

Approximately 60% of non-detections in the Six-Year Review-ICR 

7 The Method Detection Limit, MDL, is defined as the minimum concentration of a substance that can be measured 

and reported with 99% confidence, based on an analyte concentration being greater than zero as determined from 

analysis of a sample in a given matrix containing the analyte. In other words, the MDL is the concentration at which 

presence or absence of an analyte can be dependably determined. This contrasts with the MRL, which is a 

concentration above the MDL, typically set 2 to 10 times the MDL, that enables reporting at specified levels of 

precision and accuracy of the actual concentration of the analyte present in the sample.

8 All the Stage 2 analyses presented in this report were conducted using a “simple substitution” approach that 

substitutes MRL values for reported analytical non-detections. The specific MRL values used were derived by 

determining modal MRL values for each contaminant based on PWS compliance monitoring analytical records 

provided by the states and compiled by EPA into the Six Year Review-ICR Dataset. The modal MRL values used to 

support the Stage 2 analyses in this report are the same as those used in the EPA Estimated Quantitation Limit 

(EQL) analyses in a separate EPA report; however, the number of analytical records used to derive the modal MRL 

values in this report is lower than the number of records used in the EQL report. Some analytical records (e.g., 

samples from transient non-community water systems) were excluded from the dataset used for the occurrence 

analyses because those records do not meet the requirements of NPDWR compliance monitoring. However, such 

records still provide valid information for analytical method assessments and therefore were retained for EPA’s EQL 

analyses.
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dataset were updated with a national modal MRL value because the data submitted by the 

states/primacy agencies did not specify an MRL. Less than 1% of the data were updated with a 

national modal MRL because the original MRL supplied was less than the minimum MDL, and 

therefore appeared to be incorrect. Approximately 5% of the non-detection data were replaced 

with the national modal MRL because the original value was greater than the national modal 

MRL. While MRLs approaching the MCL concentration are possible, their inclusion could 

inflate Stage 2 occurrence estimates that generate system long-term mean concentrations using 

the MRL values as surrogates for sample non-detections. In these calculations, the MRL values 

used have a very limited effect on the resulting estimates of contaminant mean concentrations. 

See Section 7 for details on the Stage 2 analysis. 

3.4 Establishing Consistent Data Fields for Analytical Results 

The datasets of those states that used the SDWIS Query Extract Tool, as well as the 

datasets of some of the states that did not, included analytical results signs (e.g., “<” for nondetections or “=” for detections), detection limits, and analytical results data in multiple fields. 

For this analysis, however, it was important to have a single data element for the result sign, 

indicating whether the record was less than or equal to the corresponding number in the Value 

field, and a single data element for the Value, equal to the analytical result if the record is a 

detect and equal to the detection limit if the record is a non-detect. A “Detect” field was added to 

all of the state datasets to identify the results sign. Wherever the analytical result was greater 

than zero and the result sign indicated a detection, then Detect was set equal to 1, representing a 

detection. When the analytical result was equal to zero and/or the result sign indicated a nondetection, then Detect was set equal to 0 (i.e., a non-detect). A “Value” field was also added to 

all of the state datasets. For all non-detections, Value was set equal to the detection limit; for all 

detects, Value was set equal to the analytical result.

3.5 Establishing Consistent Analytical Units 

Data were received in a variety of units. However, the data for each individual 

contaminant needed to be expressed in a single unit in order to facilitate analysis. Chemical 

monitoring data were received in both milligrams per liter (mg/L) and micrograms per liter 

(μg/L). For this analysis, all data for IOCs were converted to mg/L, while all data for the 

synthetic organic chemicals SOCs, VOCs, and uranium were converted to μg/L. Data for alpha 

particles, beta particles,9

 and combined radium-226/228 were analyzed in picocuries per liter 

(pCi/L).

3.6 Records Excluded from Analyses 

All monitoring data from purchased systems (systems that purchase 100% of their water) 

were excluded from the final Six-Year Review-ICR Dataset because these systems have different 

9 Although the MCL for beta particles, 4 mrem/yr, is in the unit of measure of millirem per year (mrem/yr), the 

primary unit of analytical measure is picocuries per liter (pCi/L). This unit of measure relates to screening thresholds 

of 15 pCi/L and 50 pCi/L that are defined in the 2000 Radionuclides Rule. More than 95% of all compliance 

monitoring data for beta particles submitted by the states to EPA were in units of pCi/L. The analyses presented here 

are based on compliance monitoring data represented in units of pCi/L and are conducted relative to the screening 

threshold of 50 pCi/L.
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monitoring requirements than the non-purchased water systems that provide the compliance 

monitoring data for the second Six-Year Review occurrence analyses.

All monitoring data from non-public water systems (systems with fewer than 25 service 

connections and that serve a population of fewer than 25) were also excluded from the analysis.10

Non-public water systems are not required to collect compliance monitoring data for regulated 

contaminants. All of the states that used the SDWIS Query Extract Tool had data from nonpublic water systems in their original data submittal.

Furthermore, only standard SDWA compliance samples for regulated contaminants were 

analyzed to generate national contaminant occurrence estimates. Any “special” or 

“investigation” samples were excluded from the working dataset. If necessary, those data could 

be managed and quality-checked separately for possible use in supplementary occurrence 

analyses. For example, any high frequency samples could support assessments of the seasonal 

occurrence of pesticides. The SDWIS Query Extract Tool was designed to pull only compliance 

monitoring data. Several states submitted non-compliance monitoring results: Arkansas, Hawaii, 

Illinois, Massachusetts, Maryland, Michigan, New Hampshire, New York, Region 9 tribes, South 

Carolina, Tennessee, and Wisconsin. In addition, the following states submitted data for 

unregulated contaminants: California, Florida, Illinois, Michigan, Minnesota, North Carolina, 

Nebraska, Region 9 tribes, South Dakota, Tennessee, Texas, and Wisconsin.

Exhibit 3-2 lists the systems that are required to sample for the contaminants within each 

chemical group. All data that passed the QA/QC process from these systems were included in the 

second Six-Year Review analyses. Data from systems that were not required to sample for a 

given contaminant (e.g., SOC data from transient systems or radionuclide data from transient or 

non-transient non-community systems) were excluded from the second Six-Year Review 

analyses.

Exhibit 3-2. Chemical Group Monitoring Requirements

Chemical Group System Types Required to Sample 

(sample data included in analyses)

System Types Not

(sample data excluded from analyses)

Required to Sample 

Inorganic 

Chemicals (IOCs)

All non-purchased community water systems 

and non-transient non-community water 

systems are required to sample for IOCs.

All purchased systems and transient noncommunity water systems are not required to 

sample for IOCs.

Nitrate and Nitrite

Non-purchased community water systems, 

non-transient non-community water systems, 

and transient non-community water systems 

are all required to sample for nitrate and

nitrite. 

All purchased systems are not required to 

sample for nitrate and nitrite

Synthetic Organic 

Chemicals 

(SOCs)

All non-purchased community water systems 

and non-transient non-community water 

systems are required to sample for SOCs. 

All purchased systems and transient noncommunity water systems are not required to 

sample for SOCs.

10 The compliance monitoring requirements for non-public water systems differ from state to state. Therefore, for 

consistency for the national occurrence analyses conducted for the second Six-Year Review, the data from all nonpublic water systems were excluded from the Six-Year Review-ICR Dataset. Collectively, the non-public water 

systems represent a very small fraction of the national population-served by public drinking water systems.
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Chemical Group System Types Required to Sample 

(sample data included in analyses)

System Types Not

(sample data excluded from analyses)

Required to Sample 

Volatile Organic 

Chemicals 

(VOCs)

All non-purchased community water systems 

and non-transient non-community water 

systems are required to sample for VOCs. 

All purchased systems and transient noncommunity water systems are not required to 

sample for VOCs.

Radiological 

Contaminants

All non-purchased community water systems 

are required to sample for the radionuclides. 

All purchased systems and non-purchased nontransient non-community and non-purchased 

transient non-community water systems are not 

required to sample for radionuclides. 

3.7 Missing System Inventory Data

For the Six-Year Review analysis, each system must have a single source water type and 

population served designation to define each system in a unique source water type/population 

size strata. Systems using both ground water and surface water, and systems using ground water 

under direct influence of surface water (GWUDI), were considered surface water systems for 

analysis. Systems with more than one specified value of their population served in the original 

data were included using their most frequently occurring population served value.

Several state datasets were missing source water type and/or population served data 

(California, Florida, South Dakota, Tennessee, and Texas). Other datasets did not include any 

inventory information in their data submittal (Massachusetts, Michigan, and Wisconsin). For 

missing system inventory data, the SDWIS/Fed database was accessed to obtain the correct 

inventory data using the unique public water system identification number, or PWSID. The 

SDWIS/Fed version accessed to obtain this inventory data was the third quarter of 2006. For 

those systems whose inventory gaps could not be filled in by SDWIS/Fed, the 1998 Drinking 

Water Needs Survey was consulted. Systems whose population and/or source water type data 

could not be found were excluded from the Six-Year 2 analyses.

3.8 Adjustments of Population Served by Public Water Systems

All purchased systems (systems purchasing 100% of their water from other systems) 

were excluded from the analyses since the compliance monitoring requirements for purchased 

systems are generally different from those for non-purchased systems. However, by excluding 

these systems, the population served by those systems would also be excluded from the 

preliminary exposure estimates conducted for the Six-Year Review. Therefore, the population 

served values of the purchased systems were linked to those systems they purchased from (the 

“wholesale systems”) and that were included in the occurrence and exposure analyses. To do 

this, EPA compiled a list of all systems that sell water directly to the consumer (“retail systems”) 

and of all retail systems that purchase 100% their water. In the list, the purchased systems were 

linked to the wholesale system from which they purchased water. The population served by each 

purchased system was added to the population served by its wholesale system. The contaminant 

occurrence measures that include these wholesale systems with their “adjusted” population 

served values include the population served by the purchased systems. 

A secondary adjustment was made to the wholesalers’ total population served values to 

address a known source of potential multiple counting of population possibly served by systems 
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with contaminant occurrence. A total of 889 purchased systems actually purchase water from 

more than one seller. There are no data available on the actual relative quantities of water 

purchased from the different wholesalers. Therefore, in the cases of multiple wholesalers, the 

population served by the purchasing system was assumed to be uniformly distributed across, and 

therefore added to, each of the wholesaler systems. Populations served would otherwise be 

counted multiple times if the entire population served of a purchased system is added to the 

population served of each and every of its multiple wholesalers. To illustrate this simple uniform 

distribution, consider a single large system serving a population of 60,300 that purchases 100% 

of its water from three different systems. The compliance monitoring data from that purchasing 

system is excluded from the occurrence analyses because it is a purchased system; however, onethird of its population served (60,300 ÷ 3 = 20,100) would be added to each of the three systems 

from which it purchases water. This way, the population served values of purchased systems are 

included in the analyses and considerations for the Six-Year Review.
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4 Data Quality Assurance/Quality Control

A significant effort was undertaken to ensure the quality of the data submitted for the 

Six-Year Review. This QA/QC effort encountered a range of data quality across the different 

contaminants and different states. Included below is a summary description of the QA/QC 

measures that were conducted on the datasets submitted by the states before the analyses of those 

state occurrence data were conducted. Not all QA/QC measures described were conducted on all 

states, as noted below. For complete details of the data QA/QC measures, refer to Cadmus

(2008).

4.1 Review of Dataset Content

When submitted by the states, data dictionary files were reviewed for a definition of the 

various data elements, field/row headings, codes, acronyms, etc. Data dictionaries were also used 

to verify that all fields of data contained only the available codes listed by the state. Data 

dictionaries were not required for data review of data from states that used the SDWIS Query 

Extract Tool to extract their data. The following states that did not use the SDWIS Query Extract 

Tool submitted data dictionaries with their datasets: California, Illinois (NTNCWS data only), 

Maryland, and New Hampshire. The other non-SDWIS Query tool states did not submit a data 

dictionary with their datasets, which necessitated extensive, often multiple, follow-up

communications with the state’s data management staff. Most of these states were contacted with 

questions regarding non-intuitive data element names, definitions of field headings, or nonstandard codes.

Field names were all standardized (e.g., changing “source” or “water type” to “source 

water type”) and data types were changed to similar formats (e.g., changing text fields to 

numeric where appropriate and setting field lengths). Data reported for each field were also 

standardized (e.g., in the “source water type” field, changed “SW” or “S” to “surface water”).

4.2 Data Element Completeness

One of the first quality checks was to verify that all of the necessary data elements were 

included in datasets submitted by the states. Many of the states not using the SDWIS Query 

Extract Tool submitted datasets with more data elements than necessary. In those cases, it was 

necessary to determine which data elements were needed for the Six-Year Review occurrence 

analyses and which were not. Exhibit 4-1 provides a detailed list of the 17 data elements 

requested by EPA for the Six-Year Review. EPA requested that, at a minimum, states provide 

the nine data elements that are in bold and marked with an asterisk to enable dependable 

occurrence analyses. Ideally, states submitted all 17 data elements with their occurrence data.
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Exhibit 4-1. Requested Data Elements

Data Element Description

Inventory Data

*

Public Water System 

Identification Number 

(PWSID)

The code used to identify each PWS. The code begins with the standard 2-character 

postal state abbreviation or Region code; the remaining 7 numbers are unique to each 

PWS in the state.

System Name Name of the PWS.

Federal Public Water 

System Type Code

A code to identify whether a system is:

• Community Water System (CWS);

• Non-transient Non-community Water System (NTNCWS); or 

• Transient Non-community Water System (TNCWS).

Population served Highest average daily number of people served by a PWS, when in operation.

Source Water Type

Type of water at the source. Source water type can be:

• Ground water (GW); or

• Surface water (SW); or

• Ground water under the direct influence of surface water (GWUDI).

Sample-Specific Information

* Sample Point 

Identification Code

A sampling point identifier established by the state, unique within each applicable 

facility, for each applicable sampling location (e.g., entry point to the distribution 

system). This information enables occurrence assessments that address intra-system 

variability.

Sample Identification 

Number Identifier assigned by state or the laboratory that uniquely identifies a sample.

* Sample Collection Date Date the sample is collected, including month, day, and year.

* Sample Purpose Indicates why the sample is being collected (e.g., compliance/routine, confirmation, 

duplicate, repeat, special, special duplicate, etc.).

* Sample Analysis Type 

Code

Code for type of water sample collected.

• Raw (Untreated) water sample

• Finished (Treated) water sample

For lead and copper only:

• Source

• Tap

For Total Coliform Rule (TCR) Repeats only; indicator of sampling location relative to 

sample point where positive sample was originally collected:

• Upstream

• Downstream

• Original

* Contaminant Contaminant name, 4-digit SDWIS contaminant identification number, or Chemical 

Abstracts Service (CAS) Registry Number for which the sample is being analyzed.

* Sample Analytical Result 

– Sign

The sign indicates whether the sample analytical result was:

• (<) "less than" means the contaminant was not detected or was detected at a level 

"less than" the MRL.

• (=) "equal to" means the contaminant was detected at a level "equal to" the value 

reported in "Sample Analytical Result - Value."

(Not required for Total Coliform Rule (TCR) data)

* Sample Analytical Result 

– Value

Actual numeric decimal value of the analysis for the chemical results, or the MRL if 

the analytical result is less than the contaminant's MRL.

For the TCR, results will indicate presence/absence. For Lead and Copper Rule 

(LCR), value requested is the 90th percentile tap water monitoring result.

* Sample Analytical Result 

– Unit of Measure

Unit of measurement for the analytical results reported (usually expressed in either 

μg/L or mg/L for chemicals; or pCi/L or mrem/yr for radionuclides).

(Not required for TCR data)
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Data Element Description

Sample Analytical Method 

Number

EPA identification number of the analytical method used to analyze the sample for a 

given contaminant.

Minimum Reporting Level 

(MRL) - Value

MRL refers to the lowest concentration of an analyte that may be reported.

(Not required for TCR data)

MRL - Unit of Measure Unit of measure to express the concentration value of a contaminant's MRL.

(Not required for TCR data)

EPA requested compliance monitoring information for chemical contaminants regulated 

under Phase I, II, IIb, and V Rules; the Arsenic Rule; and the Radionuclides Rule. EPA also 

requested data for lead, copper, acrylamide, and epichlorohydrin. Lead and copper occurrence 

data were not analyzed as part of this second Six-Year Review because occurrence analyses are 

being conducted as part of other ongoing EPA reviews specific to lead and copper. Although 

acrylamide and epichlorohydrin are regulated contaminants and are included in the second SixYear Review process, there are currently no acceptable laboratory analytical methods for 

detecting acrylamide or epichlorohydrin in drinking water.11 Therefore, given very limited 

monitoring data that are neither complete nor representative, no occurrence analyses were 

conducted for acrylamide or epichlorohydrin.

EPA also requested data for total coliforms, fecal coliforms, and Escherichia coli (E.

coli); similarly, these data are being assessed separately under the current Total Coliform Rule

(TCR) development and were not assessed here as part of the second Six-Year Review. Exhibit 

4-2, below, lists the specific contaminants for which EPA requested monitoring data. It was 

necessary to confirm that all of the requested contaminants were included in each state dataset. 

When a state was missing data for a contaminant, the state was contacted to identify the reason

for the omission, such as a statewide waiver for the contaminant(s).

Exhibit 4-2. List of Contaminants for Which Data Were Requested from States

Chemical Contaminants (Phase I, II, IIB, and V Rules; Arsenic Rule; Lead and Copper Rule)

Acrylamide 1,2-Dichloroethane 

(Ethylene dichloride)

Lindane (gammaHexachlorocyclohexane)

Alachlor 1,1-Dichloroethylene Mercury (Inorganic)

Antimony cis-1,2-Dichloroethylene Methoxychlor

Arsenic trans-1,2-Dichloroethylene Nitrate (as N)

Asbestos Dichloromethane (Methylene chloride) Nitrite (as N)

Atrazine 1,2-Dichloropropane Oxamyl (Vydate)

Barium Di(2-ethylhexyl)adipate (DEHA) Pentachlorophenol

Benzene Di(2-ethylhexyl)phthalate (DEHP) Picloram

11 Both acrylamide and epichlorohydrin are sometimes used in drinking water treatment processes. In lieu of an 

MCL and compliance monitoring that enables assessments of occurrence relative to an MCL, each water system 

must certify, in writing, to the state, using third-party or manufacturer's certification, that when acrylamide and 

epichlorohydrin are used in drinking water systems, the combination, or product of dose and monomer level does 

not exceed the levels specified, as follows: acrylamide = 0.05% dosed at 1 mg/L and epichlorohydrin = 0.01% dosed 

at 20 mg/L.
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Chemical Contaminants (Phase I, II, IIB, and V Rules; Arsenic Rule; Lead and Copper Rule)

Benzo[a]pyrene Dinoseb Polychlorinated biphenyls (PCBs)

Beryllium 2,3,7,8-TCDD (Dioxin) Selenium

Cadmium Diquat Simazine

Carbofuran Endothall Styrene

Carbon tetrachloride Endrin Tetrachloroethylene (PCE)

Chlordane Epichlorohydrin Thallium

Monochlorobenzene Ethylbenzene Toluene

Chromium (Total) Ethylene dibromide (EDB) Toxaphene

Copper Fluoride 2,4,5-Trichlorophenoxypropionic

Acid (Silvex)

Cyanide Glyphosate 1,2,4-Trichlorobenzene

2,4-Dichlorophenoxyacetic acid

(2,4-D) Heptachlor 1,1,1-Trichloroethane

Dalapon Heptachlor epoxide 1,1,2-Trichloroethane

1,2-Dibromo-3-chloropropane (DBCP) Hexachlorobenzene Trichloroethylene (TCE)

1,2-Dichlorobenzene 

(o-Dichlorobenzene) Hexachlorocyclopentadiene Vinyl chloride

1,4-Dichlorobenzene 

(p-Dichlorobenzene) Lead Xylenes (Total)

Radiological Contaminants

Combined Radium-226/228; and 

Radium-226 & Radium-228 (if 

available)

Beta particles Tritium

Iodine-131

Uranium

Alpha particles Strontium-90

Microbiological Contaminants

Total coliforms Fecal coliforms Escherichia coli (E. coli)

The date range of each state’s compliance monitoring sample collection was also 

reviewed to determine if all of the requested years of data were included. Any data not collected 

between 1998 and 2005 were removed from the working datasets. Some states were not able to 

submit all requested years of data because they only began storing their data electronically 

sometime after 1998 (e.g., Arkansas, Connecticut, Delaware, and Hawaii). Some states alerted

EPA of this issue when they submitted their data; other states had to be contacted to confirm that 

the missing years of data were not available electronically. In addition, any records from 

obviously incorrect sample dates (e.g., data from year “1900”) were removed. 

4.3 Potential Outliers and Incorrect Units 

To address the data management steps described above, for example, obviously incorrect 

sample dates, it was seldom necessary to discuss the corrections with state data management 

staff. However, to resolve data quality issues that required significant corrections to the raw data, 

such as identifying and deleting outliers or identifying and changing incorrect units, state data 

management staff were consulted when appropriate before any data corrections were completed.
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For each state and contaminant, EPA conducted a review for possible outliers or units 

problems by calculating basic summary statistics, such as the minimum, median and maximum 

of detections and non-detections. Summary statistics for each contaminant were compared across 

states to check for reasonableness and general consistency regarding range of values. The 

distributions of all detection and non-detection values were also compiled and ranked to facilitate

assessment. Generally, there should be a smooth, continuous distribution of the actual quantified 

concentrations of contaminants detected and a somewhat step-wise distribution of non-detections 

reflecting the different concentrations marking the different analytical methods’ reporting levels. 

Any detected values that are, for example, a thousand-fold lower than most other low detection 

values likely reflect an analytical unit conversion problem (mg/L versus μg/L) in the original raw 

data. Furthermore, all detection values that were less than one-tenth the MDL were flagged and 

investigated as potential outliers. All detections with values greater than 10 times the MCL 

concentration were also flagged and investigated as potential outliers or units problems. In 

addition, these records were compared to MCL violation records contained in the SDWIS/Fed 

database.

The water source type (i.e., raw or finished) of each outlier was also investigated. In 

some states, systems are allowed to monitor at source (raw) water sampling points. If a 

contaminant is detected in a source water sample, the system is required to collect a follow-up

sample at the entry point to the distribution system, unless there was no treatment. If an outlier 

was from raw water and it had a corresponding finished water sample (i.e., a finished water 

sample from the same or next day), then the raw water outlier was removed from the dataset. If 

there was no corresponding finished water sample and the sample was marked as a compliance 

sample, then the raw water outlier was usually retained in the dataset, unless there was further 

evidence to remove the record. Some states stored raw water non-compliance samples along with 

finished water samples; those non-compliance samples were removed from the dataset.

About 30 states were contacted about apparently incorrect units of measure for particular 

contaminants. Note that states were contacted even when only a small number of records were in 

what appeared to be incorrect units. For example, asbestos data are typically expressed in million 

fibers per liter (MFL). However, a small portion of asbestos data in numerous state datasets were

expressed in mg/L. In all cases, the states verified that there was a data entry error in the unit of 

measure field and the data should have been reported in MFL. Similarly, alpha particles and 

combined radium data are typically expressed in pCi/L. State data management staff were

contacted when alpha particles and/or combined radium data were listed in the database in mg/L 

or μg/L. Again, in most cases, states verified that there had been a data entry error and the data 

were indeed in pCi/L.

The apparent very high or very low detections records (i.e., potential outliers) comprised

less than 0.5% of total detections. Forty-two of the 45 state datasets contained potential outliers 

in their chemical or radionuclide data. Less than 0.5% of the total number of analytical results 

was identified as having been recorded in the incorrect units. Less than 0.06% of the analytical 

detections were changed to non-detections after investigation. Of the total number of records 

excluded from analysis, less than 0.04% of the total number of analytical results were removed 

as suspected or confirmed outliers. Less than 3% of the total number of records compiled were 

removed for other reasons including: records were not for compliance (i.e., records from 

transient non-community water systems for chemicals other than nitrate and nitrite), records 
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were for “special” or “investigation” studies, or records were raw water/non-compliance samples 

or further communications with states suggested records were not dependable or were probable 

data entry errors.
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5 Summary of the Compliance Monitoring Data

This section provides an overview of the data that were received, passed the QA/QC 

process, and were analyzed for second Six-Year Review. Also provided is information on the 

total number of systems in the final Six-Year Review-ICR dataset, characteristics of the systems 

such as system types, source water types, population served, the number of records from each 

state, and the number of records for each contaminant. An assessment of contaminant occurrence 

variability over the eight years was also conducted.

5.1 Characteristics of the Data - States, Systems and Records

Exhibit 5-1 shows the number and percent of systems and population served by systems 

according to source water type in the Six-Year Review-ICR Dataset. Exhibit 5-2 shows the 

number and percent of systems and population served by systems according to source water type

and system size. Source water types are stratified by all classifications, and summaries of GW 

and SW groupings are also presented. For analysis of these data, EPA followed its standard 

practice of treating GWUDI as surface water.

Exhibit 5-1. Number of Systems and Population Served by Systems in the 

Six-Year Review-ICR Dataset, by Source Water Type

Source Water Type

Systems Population Served

Number Percent of Total Number Percent of Total

Ground Water (GW) 126,079 95.8% 100,095,915 39.4%

Ground Water Under the Direct 

Influence of Surface Water (GWUDI) 759 0.6% 2,294,688 0.9%

Surface Water (SW) 4,712 3.6% 151,403,808 59.7%

Total 131,550 100.0% 253,794,411 100.0%

Exhibit 5-2. Number of Systems and Population Served by Systems in the

Six-Year Review-ICR Dataset, by System Size

System Size

(Population 

Served by the 

System)

Ground Water (GW) Surface Water (SW) Total

Number of 

Systems

Population 

Served by 

Systems

Number of 

Systems

Population 

Served by 

Systems

Number of 

Systems

Population 

Served by 

Systems

< 50 43,465 1,233,869 488 13,349 43,953 1,247,218

50 – 100 32,778 2,398,181 456 33,810 33,234 2,431,991

101 – 500 33,927 7,923,786 958 49,671 34,885 8,173,457

501 – 1,000 6,606 4,835,018 368 281,406 6,974 5,116,424
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System Size

(Population 

Served by the 

System)

Ground Water (GW) Surface Water (SW) Total

Number of 

Systems

Population 

Served by 

Systems

Number of 

Systems

Population 

Served by 

Systems

Number of 

Systems

Population 

Served by 

Systems

1,001 – 3,300 5,363 9,785,319 848 1,722,092 6,211 11,507,411

3,301 – 10,000 2,440 13,919,445 900 5,601,547 3,340 19,520,992

10,001 – 50,000 1,239 26,598,895 962 22,503,031 2,201 49,101,926

50,001 – 100,000 176 11,885,651 227 15,707,058 403 27,592,709

100,001 – 1million 83 17,866,469 244 63,627,821 327 81,494,290

> 1 million 2 3,649,282 20 43,958,711 22 47,607,993

Total 126,079 100,095,915 5,471 153,698,496 131,550 253,794,411

Exhibit 5-3 shows the number and percent of systems in the Six-Year Review-ICR 

dataset by system type. Although almost 60% of the systems are transient water systems, more 

than 90% of the population is served by CWSs. Only a small fraction of transient systems 

collected data for most of the Six-Year contaminants, as transient systems are only required to 

collect nitrate and nitrite samples.

Exhibit 5-3. Number of Systems and Population Served by Systems in the

Six-Year Review-ICR Dataset, by System Type

System Type

Systems Population Served

Number Percent of Total Number Percent of Total

Community Water System 

(CWS) 37,214 28.3% 238,001,491 93.8%

Non-Transient Non-Community 

Water System (NTNCWS) 18,321 13.9% 5,330,069 2.1%

Transient Non-Community 

Water System (TNCWS)1 75,701 57.5% 10,439,519 4.1%

Unknown2 314 0.2% 23,332 0.0%

Total 131,550 100.0% 253,794,411 100.0%

1. Only the nitrate/nitrite regulations require compliance monitoring by these transient systems; thus, data from the 

transient systems were included only for the nitrate and nitrite occurrence analyses and were excluded for all 

occurrence analyses for IOCs, SOCs, VOCs, and radiological contaminants. 

2. Systems with unknown system type were included in the second Six-Year Review analyses. None of the 

occurrence analyses conducted for the second Six-Year Review required specifying the system type.

Exhibit 5-4 lists the total number of records, systems and population served by systems in 

each of the 47 state/tribal datasets used in the second Six-Year Review analyses. In addition, the 

last column of the table lists any contaminant(s) for which the state did not provide data.
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Exhibit 5-4. An Inventory of Contaminant Occurrence Data in 

the Six-Year Review-ICR Dataset, by State

State

Number of 

Records for 

Regulated 

Contaminants

Number of 

Systems with 

Data for 

Regulated 

Contaminants

Population 

Served by 

Systems with 

Data for 

Regulated 

Contaminants

Did not submit useable data for 

the following regulated contaminants:

Alabama 76,160 425 4,741,994 Uranium

Alaska 97,245 1,477 712,666

Arizona 562,499 1,663 6,292,843

Arkansas 136,204 456 2,453,733

Nitrate; Nitrite; Asbestos; Dioxin; 1,4-

Dichlorobenzene; Alpha Particles; Uranium; 

Combined Radium-226/228

California 3,119,746 7,605 38,646,890 Alpha Particles

Colorado 200,141 1,748 5,259,232

Connecticut 243,589 2,918 2,787,413

Delaware 64,598 580 778,333 Dioxin; Alpha Particles; Uranium

Florida 213,208 6,261 18,939,279 Combined Radium-226/228; Beta Particles

Georgia 236,424 1,931 7,500,353 Alpha Particles; Uranium; Beta Particles

Hawaii 89,664 116 1,310,187

Asbestos; Dalapon; Diquat; Endothall; Di(2-

ethylhexyl)adipate; Di(2-

ethylhexyl)phthalate; Picloram; Dinoseb; 

Dioxin; 2,4-D; Silvex; Benzo[a]pyrene; 

Pentachlorophenol; cis-1,2-

Dichloroethylene; PCBs; Xylenes (Total); 

trans-1,2-Dichloroethylene; 

Monochlorobenzene; Alpha Particles;

Uranium; Combined Radium-226/228; Beta

Particles

Idaho 196,392 1,955 1,206,368

Illinois 338,647 3,957 9,630,392 Dioxin; Alpha Particles

Indiana 255,992 5,338 5,492,975 Uranium

Iowa 116,123 1,899 2,653,189 Dioxin

Kentucky 151,467 298 4,619,135 Uranium

Maine 167,518 2,257 950,371 Dioxin; Beta Particles

Maryland 302,133 4,105 5,279,878 Ethylene dibromide

Massachusetts 487,119 1,697 8,738,481 PCBs; Alpha Particles; Combined Radium226/228

Michigan 648,331 14,521 8,850,281 Asbestos; Dioxin; PCBs; Uranium; 

Combined Radium-226/228; Beta Particles

Minnesota 462,853 9,408 4,898,639 Asbestos; Diquat; Endothall; Dioxin; PCBs; 

Combined Radium-226/228

Missouri 422,324 2,691 4,976,894 Asbestos; Diquat; Endothall; Glyphosate; 

Dioxin; PCBs

Montana 208,602 1,014 786,930

Nebraska 280,012 792 1,469,627 PCBs; Beta Particles

Nevada 154,959 577 998,101

New Hampshire 376,523 2,643 1,282,866 Dalapon; Diquat; Endothall; Dioxin; PCBs; 

Alpha Particles; Uranium; Combined 
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State

Number of 

Records for 

Regulated 

Contaminants

Number of 

Systems with 

Data for 

Regulated 

Contaminants

Population 

Served by 

Systems with 

Data for 

Regulated 

Contaminants

Did not submit useable data for 

the following regulated contaminants:

Radium-226/228; Beta Particles

New Jersey 602,842 4,221 8,258,339 Dioxin; PCBs

New Mexico 302,188 885 1,735,210

New York 297,902 6,677 14,827,610

North Carolina 944,007 6,559 7,351,966 Diquat; Endothall; Glyphosate

North Dakota 23,272 218 563,112 Beta Particles

Ohio 353,781 5,078 10,691,928

Oklahoma 125,218 1,036 3,173,290

Asbestos; Endrin; Lindane; Methoxychlor; 

Toxaphene; Dalapon; Diquat; Endothall; 

Di(2-ethylhexyl)adipate; Simazine; Di(2-

ethylhexyl)phthalate; Picloram; Dinoseb; 

Hexachlorocyclopentadiene; Atrazine; 

Alachlor; Dioxin; Heptachlor; Heptachlor 

Epoxide; 2,4-D; Silvex; 

Hexachlorobenzene; Benzo[a]pyrene; 

Pentachlorophenol; PCBs; DBCP; Ethylene 

dibromide; Chlordane; Alpha Particles; 

Uranium; Combined Radium-226/228; Beta 

Particles

Oregon 140,912 2,672 3,182,082

Rhode Island 85,834 470 968,684 Dioxin; PCBs

South Carolina 228,336 1,650 3,777,736 Cyanide; Dioxin; PCBs; Beta Particles

South Dakota 52,155 432 676,911 Dioxin

Tennessee 1 93,045 369 5,686,766 Uranium; Combined Radium-226/228; Beta 

Particles

Texas 1,186,434 6,453 25,418,822 Asbestos; Diquat; Endothall; Glyphosate; 

Dioxin

Utah 478,540 999 2,638,287 Uranium

Vermont 159,271 1,317 596,375

Virginia 153,870 1,820 6,245,276 Dioxin

West Virginia 59,916 1,123 1,503,712 Dioxin

Wisconsin 439,365 7,013 4,418,338 Di(2-ethylhexyl)phthalate; Alpha Particles

Wyoming 86,661 636 521,508

Total 15,450,283 127,960 253,794,411 

1. Tennessee submitted data from a total of 807 PWSs. Data from 392 of these systems, with an associated 

population served of 73,512, were inadvertently excluded from the Six-Year Review analyses and the error was not 

discovered until after all analyses had been conducted. Only 38 of these systems, with an associated population 

served of 14,771, were non-purchased community or non-transient non-community water systems that would have 

been analyzed as part of the second Six-Year Review, with the exception of nitrate and nitrite. The omission of this 

small number of systems (0.03% of the national total) has very little effect on the national occurrence estimates 

generated with the Six-Year Review-ICR dataset. Contaminant occurrence rates were generated for the omitted 

systems (e.g., percent of sample detections and percent of systems with at least one detection) and the occurrence 

rates for the omitted PWSs were very similar to the overall national rates. Of the omitted Tennessee systems, 

approximately 390 and 190 were non-purchased water systems (CWSs, NTNCWSs, and TNCWSs) that provided 

nitrate and nitrite data, respectively. Nitrate and nitrite occurrence rates were generated for the omitted systems and 
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the occurrence rates for the omitted PWSs were, again, very similar to, and often less than, the overall national rates 

of nitrate and nitrite occurrence.

Exhibit 5-5 summarizes the Six-Year Review-ICR Data by contaminant. For each 

contaminant, this table includes MCL concentration values, the number of states with data, total 

number of records, systems, and the population served by systems that have data represented in 

the Six-Year Review-ICR Dataset. Also presented are the modal MRL values for each 

contaminant, derived as the mode of state modal MRLs. See Section 3.3 for details regarding 

modal MRL values.

Exhibit 5-5. An Inventory of the Contaminant Occurrence Data in 

the Six-Year Review-ICR Dataset, by Contaminant

Contaminant

(MCL Concentration)

Number 

of States 

with Data

Total 

Number of 

Records

Total 

Number of 

Systems

Total 

Population

Served by 

Systems

MRL

Inorganic Chemicals

Antimony

(0.006 mg/L) 45 185,986 49,016 223,251,662 0.001 mg/L

Arsenic 1

(0.05 mg/L) 45 224,035 49,473 230,393,228 0.005 mg/L

Asbestos

(7 MFL) 38 18,181 8,278 85,161,934 0.2 MFL

Barium

(2 mg/L) 45 183,118 49,125 229,775,707 0.1 mg/L

Beryllium

(0.004 mg/L) 45 183,575 48,021 221,383,819 0.001 mg/L

Cadmium

(0.005 mg/L) 45 181,667 48,920 229,685,370 0.001 mg/L

Chromium (Total)

(0.1 mg/L) 45 185,952 48,908 229,628,430 0.01 mg/L

Cyanide

(0.2 mg/L) 44 120,368 32,067 162,458,600 0.005 mg/L

Fluoride

(4 mg/L) 45 333,211 48,600 233,569,199 0.1 mg/L

Mercury (Inorganic)

(0.002 mg/L) 45 181,629 48,859 229,853,379 0.0002 mg/L

Nitrate (as N)

(10 mg/L) 44 1,052,487 119,537 229,508,036 0.1 mg/L

Nitrite (as N)

(1 mg/L) 44 397,175 86,313 207,984,813 0.1 mg/L

Selenium

(0.05 mg/L) 45 181,684 48,925 229,863,411 0.005 mg/L

Thallium

(0.002 mg/L) 45 185,047 48,925 223,324,845 0.0005 mg/L

Synthetic Organic Chemicals 2

Alachlor

(2 μg/L) 44 155,989 36,845 197,311,966 0.2 μg/L

Atrazine

(3 μg/L) 44 161,690 37,215 200,372,590 0.1 μg/L

Benzo(a)pyrene

(0.2 μg/L) 43 119,871 28,578 184,144,163 0.02 μg/L
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Contaminant

(MCL Concentration)

Number 

of States 

with Data

Total 

Number of 

Records

Total 

Number of 

Systems

Total 

Population

Served by 

Systems

MRL

Carbofuran

(40 μg/L) 45 114,142 31,097 167,973,342 0.9 μg/L

Chlordane

(2 μg/L) 44 128,453 31,841 182,036,975 0.2 μg/L

Dalapon

(200 μg/L) 42 112,423 28,387 178,186,111 1 μg/L

Di(2-ethylhexyl)adipate (DEHA)

(400 μg/L) 43 121,792 28,902 184,134,674 0.02 μg/L

Di(2-ethylhexyl)phthalate (DEHP)

(6 μg/L) 42 120,846 27,667 179,948,572 0.6 μg/L

1,2-Dibromo-3-chloropropane 

(DBCP) (0.2 μg/L) 44 231,169 37,618 193,749,339 0.6 μg/L

2,4-Dichlorophenoxyacetic acid

(70 μg/L) 43 124,285 33,187 187,451,183 0.1 μg/L

Dinoseb

(7 μg/L) 43 121,896 32,713 182,919,390 0.2 μg/L

Diquat

(20 μg/L) 38 55,634 15,595 120,622,647 2 μg/L

Endothall

(100 μg/L) 38 49,820 14,156 118,536,801 9 μg/L

Endrin

(2 μg/L) 44 134,336 32,783 184,043,162 0.01 μg/L

Ethylene Dibromide (EDB)

(0.05 μg/L) 43 218,797 36,215 188,153,915 0.01 μg/L

Glyphosate

(700 μg/L) 42 58,174 16,351 116,276,011 6 μg/L

Heptachlor

(0.4 μg/L) 44 133,726 33,020 184,443,784 0.04 μg/L

Heptachlor Epoxide

(0.2 μg/L) 44 134,708 33,015 184,477,775 0.02 μg/L

Hexachlorobenzene

(1 μg/L) 44 135,512 32,826 184,124,823 0.1 μg/L

Hexachlorocyclopentadiene

(50 μg/L) 44 135,290 32,801 184,738,430 0.1 μg/L

Lindane (gammaHexachlorocyclohexane) (0.2 μg/L) 44 135,585 33,265 187,258,935 0.02 μg/L

Methoxychlor

(40 μg/L) 44 137,068 33,421 187,636,119 0.1 μg/L

Oxamyl (Vydate)

(200 μg/L) 45 113,380 30,876 167,378,431 2 μg/L

Pentachlorophenol

(1 μg/L) 43 136,475 34,339 190,507,709 0.04 μg/L

Picloram

(500 μg/L) 43 121,920 32,910 186,386,430 0.1 μg/L

Polychlorinated biphenyls (PCBs)

(0.5 μg/L) 34 67,216 18,393 124,114,208 0.1 μg/L

Simazine

(4 μg/L) 44 158,256 36,830 196,986,505 0.07 μg/L

Toxaphene

(3 μg/L) 44 115,403 30,387 160,012,134 1 μg/L

2,3,7,8-TCDD (Dioxin)

(0.00003 μg/L) 27 11,076 2,383 52,854,445 0.000005 μg/L

2,4,5-Trichlorophenoxypropionic 

Acid (Silvex) (50 μg/L) 43 122,713 32,887 183,000,768 0.2 μg/L
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Contaminant

(MCL Concentration)

Number 

of States 

with Data

Total 

Number of 

Records

Total 

Number of 

Systems

Total 

Population

Served by 

Systems

MRL

Volatile Organic Chemicals

Benzene

(5 μg/L) 45 374,503 50,435 226,947,293 0.5 μg/L

Carbon Tetrachloride

(5 μg/L) 45 385,864 50,446 226,934,787 0.5 μg/L

1,2-Dichlorobenzene

(600 μg/L) 45 372,946 50,422 226,929,816 0.5 μg/L

1,4-Dichlorobenzene

(75 μg/L) 44 370,698 49,969 224,476,625 0.5 μg/L

1,2-Dichloroethane

(5 μg/L) 45 375,636 50,442 226,933,991 0.5 μg/L

1,1-Dichloroethylene

(7 μg/L) 45 378,630 50,425 226,909,664 0.5 μg/L

cis-1,2-Dichloroethylene

(70 μg/L) 44 373,316 50,314 225,615,734 0.5 μg/L

trans-1,2-Dichloroethylene

(100 μg/L) 44 371,258 50,319 225,611,137 0.5 μg/L

Dichloromethane (Methylene 

Chloride) (5 μg/L) 45 372,009 50,169 226,844,060 0.5 μg/L

1,2-Dichloropropane

(5 μg/L) 45 374,409 50,437 226,912,134 0.5 μg/L

Ethylbenzene

(700 μg/L) 45 374,141 50,447 226,939,375 0.5 μg/L

Monochlorobenzene

(100 μg/L) 44 370,519 50,311 225,627,782 0.5 μg/L

Styrene

(100 μg/L) 45 372,269 50,421 226,933,636 0.5 μg/L

Tetrachloroethylene (PCE)

(5 μg/L) 45 410,042 50,436 227,008,555 0.5 μg/L

Toluene

(1,000 μg/L) 45 374,250 50,451 226,955,301 0.5 μg/L

1,2,4-Trichlorobenzene

(70 μg/L) 45 371,132 50,135 226,842,102 0.5 μg/L

1,1,1-Trichloroethane

(200 μg/L) 45 374,950 50,440 226,931,546 0.5 μg/L

1,1,2-Trichloroethane

(5 μg/L) 45 372,386 50,195 226,851,469 0.5 μg/L

Trichloroethylene (TCE)

(5 μg/L) 45 403,609 50,432 226,907,686 0.5 μg/L

Vinyl Chloride

(2 μg/L) 45 373,161 50,411 226,464,423 0.5 μg/L

Xylenes (Total) 

(10,000 μg/L) 44 363,466 47,698 218,071,535 0.5 μg/L

Radiological Contaminants

Alpha Particles

(15 pCi/L) 35 73,002 18,653 121,170,400 1 pCi/L

Beta Particles

(screening level = 50 pCi/L) 3 34 59,983 14,231 120,274,924 4 pCi/L

Combined Radium-226 & -228

(original Radionuclides rule)

(5 pCi/L) 4 35 18,452 6,884 47,422,440 1 pCi/L
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Contaminant

(MCL Concentration)

Number 

of States 

with Data

Total 

Number of 

Records

Total 

Number of 

Systems

Total 

Population

Served by 

Systems

MRL

Combined Radium-226 & -228

(revised Radionuclides rule)

(5 pCi/L) 4 33 18,050 3,893 41,426,437 1 pCi/L

Uranium

(30 μg/L) 33 41,581 5,921 70,631,392 0.001 μg/L

1. The MCL concentration for arsenic is currently 0.01 mg/L. The Six-Year data were analyzed relative to the former 

MCL concentration of 0.05 mg/L because that was the MCL during the period of review for the Six-Year 2 analysis,

1998 through 2005. However, additional analyses relative to the new arsenic MCL concentration are included in 

Appendix A.

2. The reduced number of systems sampling for SOC data, as compared to IOCs and VOCs, likely relates to state 

waivers for pesticides and herbicides.

3. Although the MCL for beta particles, 4 millirem per year (mrem/yr), is in the unit of measure of mrem/yr, the primary 

unit of analytical measure is picocuries per liter (pCi/L). This unit of measure relates to screening thresholds of 15 

pCi/L and 50 pCi/L that are defined in the 2000 Radionuclides Rule. More than 95% of all compliance monitoring data 

for beta particles submitted by the states to EPA were in units of pCi/L. The analyses presented here are based on 

compliance monitoring data represented in units of pCi/L and are conducted relative to the screening threshold of 50 

pCi/L.

4. The revised Radionuclides Rule, published in 2000, went into effect on December 8, 2003 so combined radium226 and -228 occurrence data collected before December 8, 2003 were analyzed and are presented in the row

labeled “original Radionuclides rule” and data collected after December 8, 2003 were analyzed and are presented in 

the row labeled “revised Radionuclides rule.”

5.2 Occurrence Variability Assessment

For the second Six-Year Review, EPA collected and analyzed eight years of compliance 

monitoring data, 1998 through 2005. The eight years of data were used to develop aggregate 

measures of occurrence (i.e., a single measure of occurrence that is based on all eight years of 

data). For example, a typical measure is the percent of systems with at least one detection of a 

particular contaminant greater than its MCL concentration. This single measure would reflect a 

count of each and every unique system with at least one detection in any of the eight years 

considered and then present a single percentage of systems with at least one detection. 

Recognizing that occurrence of a particular contaminant might vary over an eight-year period, 

EPA conducted assessments to determine if the compliance monitoring data in the Second SixYear Review-ICR dataset exhibit significant variability over time. 

To make these assessments, it was not possible to simply evaluate yearly sample 

detection rates for each contaminant at the national level. Monitoring schedules for a particular 

contaminant can differ from system-to-system and year-to-year (e.g., not all surface water 

systems monitor all contaminants quarterly). Therefore, a national comparison of system 

monitoring data from different years will typically be a comparison of data from different subsets 

of systems nationally. The variation in compliance monitoring schedules generally corresponds 

to the assessed chance of contaminant occurrence based on historic monitoring results at each 

system. If a contaminant is shown not to occur at a system through a specified period of routine 

compliance monitoring, that system is authorized to conduct a reduced monitoring schedule for 

that contaminant. Some systems monitor contaminants as infrequently as once every year, every 

three years, or even every nine years. Because of this variability in monitoring schedules and its 
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implications (i.e., the frequency and timing of sampling are not random), a simple year-to-year 

assessment of occurrence across all systems does not provide a clear, unambiguous assessment 

of occurrence variability.

To evaluate that the observed variability in the occurrence measures are due to changes in 

contaminant occurrence rather than differences or changes in monitoring schedules, EPA 

identified systems that collected at least one sample in the 1998-2001 period of data and at least 

one sample in the 2002-2005 period. This enabled a comparison of occurrence based on a more 

consistent set of systems. EPA then quantified contaminant occurrence at the system level in the 

first four years and in the second four years, and used standard statistical t-tests to determine 

whether system level occurrence in the first four years was significantly different from system 

level occurrence in the second four years.

There is no single “correct” measure of occurrence for assessing variability. Contaminant 

occurrence variability can be based on a number of different measures such as contaminant 

detection rates, concentration averages, or the frequency at which systems find a contaminant 

above some concentration threshold. Occurrence also is defined by a relatively small number of 

samples from each system, as expected given compliance monitoring requirements. Given these 

factors, the variability assessments are subject to some uncertainty and results varied depending 

on the specific measures employed, such as detection rates, concentration averages, etc. The 

results also depended on which systems were included in the assessment. One group of 

assessments included only systems with at least one sample in each of the eight years of data 

while the second group of assessments included only systems with at least one annual sample 

during 1998-2001 and another during 2002-2005.

EPA conducted six different time-dependent variability assessments, comparing

measures of detection rates, concentration averages, and exceedance rates for the two different 

groups of systems described above. Findings of variability are based on the collective results of 

these six assessments. For 62 of the 69 contaminants assessed, there is no statistically significant 

variability in occurrence between the 1998-2001 and 2002-2005 time periods, regardless of the 

specific occurrence measure assessed. For the other seven contaminants, at least one occurrence

measure for each of the contaminants was statistically found to be different in the two time 

periods.12

12 Variability of occurrence over time was determined using t-tests to measure whether or not there was a 

statistically significant difference between occurrence measures from the two time periods. Statistical significance 

was determined by the use of standard t-tests which compare two sets of values, such as estimated average detection 

rates, and calculates the probability that the mean value or central tendency, of the first set of data is the same as the 

mean value of the second set of values. If this calculated probability is low (<5% is a common defining threshold), 

then the conclusion is that the central tendency of the first set of values is “significantly” different from the central 

tendency of the second set. The t-tests used means, variances, and sample sizes to determine whether the likelihood 

of the null hypothesis which is that the data were not significantly different, was less than 5% (i.e., a p-value less 

than 0.05).

Most of the contaminants with occurrence variability over time had a decrease in 

occurrence over the eight-year period including thallium in SW, 1,1,1-trichloroethane in GW , 

and dichloromethane, 1,2-dichloroethane, and carbon tetrachloride in GW and SW. Showing an

increase in occurrence over the eight-year period was fluoride in GW and 

hexachlorocyclopentadiene in SW. Since multiple measures of occurrence were assessed, it is 

difficult to define an actual quantitative amount of decrease or increase for these seven 

contaminants over the eight-year period. Generally, these findings indicate that it is appropriate 
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to use an aggregation of the eight years of data for the occurrence estimates for the second SixYear Review. For the nine contaminants with at least some statistically significant measure of 

increasing or decreasing occurrence, these findings are most appropriately used as context or 

background for the quantitative occurrence findings presented in Sections 6 and 7 of this report. 

5.3 Threshold Evaluations

EPA assessed the occurrence of the regulated contaminants relative to several different 

thresholds or concentration values. Stage 1 and Stage 2 assessments of occurrence were made 

relative to the MRL, identifying the simple presence/absence of a detection of a contaminant. A

sample analytical result is defined as a “detection” if the quantified sample concentration of the 

contaminant is equal to or greater than that contaminant’s MRL.

Contaminant occurrence was also evaluated relative to higher contaminant concentration 

thresholds including a contaminant’s MCL concentration. For Stage 1 and Stage 2 analyses 

relative to an MCL concentration, the criterion is for any analytical results to exceed the 

concentration value of a specific contaminant’s MCL. The Stage 1 analyses would identify any 

single result greater than the MCL concentration and the Stage 2 analyses would identify system 

estimated long-term (multi-year) average concentrations greater than the MCL concentration. 

The analyses conducted here, though, are not equivalent to the analyses conducted to 

estimate a potential MCL violation. Both these Stage 1 and Stage 2 analyses are based on every 

analytical sample result from all years with data in the Six Year Review-ICR Dataset. The Stage 

2 analysis (based on an estimated long-term average concentration) is similar to the calculation 

conducted to determine an MCL violation, but the two calculations are different. For most 

regulated drinking water contaminants, an MCL violation occurs when the concentration equal to 

a contaminant’s MCL is exceeded by the estimated annual average concentration based on a 

limited number of consecutive quarterly compliance monitoring samples (typically four for 

surface water systems and two for ground water systems).13 In contrast, a “Stage 2 MCL

exceedance” occurs when the concentration threshold equal to a particular contaminant’s MCL is 

exceeded by the estimated system average concentration based on multiple years (not two or four

consecutive quarters) of compliance monitoring samples. Calculations of MCL violations are not

conducted in this report.

13 For nitrate and nitrite, if a single sample result is greater than or equal to the MCL, the system must collect a 

confirmation sample and average it with the original sample. If that average is greater than the MCL, then an MCL 

violation has occurred.
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6 Stage 1 Analysis

The Stage 1 statistical analysis of the second Six-Year Review-ICR dataset consists of 

simple counts and descriptive statistics of the occurrence data for each of the regulated 

contaminants assessed. National contaminant occurrence estimates are conducted relative to 

contaminant MRLs and MCL concentrations and are presented by systems and population served 

by systems in Section 6.1. A comparison of the summary Stage 1 analysis results from the first 

Six-Year Review with data from 1993-1997 and the current Six-Year Review with data from 

1998-2005, is presented in Section 6.2. A supplemental measure of occurrence, based on 

occurrence at sample point locations within each system, using the 1998-2005 data is described 

in Section 6.3 with summary sample point estimates presented in Exhibit 6-3.

Also included in Appendix A are additional occurrence measures conducted for samples, 

systems, and population served by systems. These additional occurrence findings are presented 

by state and for the nation as a whole. For the sample occurrence assessments, occurrence 

measures include the number and percent of samples for each contaminant with analytical 

detections; and the minimum, median, maximum, and 90th percentile values of those detections.

System-level occurrence measures include the number and percent of systems with one or more 

analytical detections, and the number and percent of systems with one or more analytical 

detections above a health threshold of concern. Population served occurrence measures include

the number and percent of customers by systems with one or more analytical detections, and the 

number and percent of population served by systems with one or more analytical detections of a 

given contaminant above a health threshold of concern.

6.1 Summary of Stage 1 Contaminant Occurrence Findings

Several Stage 1 analyses were conducted to characterize national occurrence of regulated 

contaminants in public drinking water systems and are summarized in Exhibits 6-1 and 6-2.

Stage 1 analyses measured occurrence at systems, for a general system-level assessment of 

occurrence, and for population served by systems, for a preliminary assessment of potential 

exposure to contaminants in drinking water. Both of these occurrence measures were conducted 

relative to a contaminant’s MRL, identifying analytical detections for a broad assessment of the 

rate of occurrence, and relative to each contaminant’s MCL concentration, making a preliminary 

estimate of occurrence and exposure at or above a contaminant’s health-based drinking water 

standard. The percent of systems and population served by systems with at least one detection 

greater than the MCL concentration indicates the proportion of all systems or population served 

by systems with any analytical results exceeding the concentration value of the MCL. Note that 

this does not indicate an MCL violation. An MCL violation occurs when the MCL is exceeded 

by the average results from four consecutive quarterly confirmation samples. These Stage 1 

analytical findings are organized by contaminant group.

Although the various measures of occurrence generally identify similar lists of higher and 

lower occurring contaminants, there are differences in the findings of the different measures and 

these differences can serve to more fully characterize national occurrence of the contaminants. 

For example, xylenes were found to be the highest occurring VOC based on the assessment 

relative to the MRL, but were also one of the lowest occurring VOCs based on the assessment 
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relative to the MCL concentration. Xylenes, in other words, are found to have the highest rate of 

occurrence, but that occurrence is almost exclusively at very low concentrations that are almost 

always below concentration thresholds at which xylenes could potentially have negative health 

effects. Another aspect of the different occurrence measures relates to the size distribution of 

systems with detections, which influences the size of the potentially exposed population. In this 

context, “small” systems serve a small population and “large” systems serve a large population.

A small number of very large systems with contaminant detections will result in a greater 

exposed population than will a larger number of small systems with detections. For example, two 

VOCs, dichloromethane and trichloroethylene, have similar percents of systems (0.293% and 

0.387%, respectively) with at least one detection greater than their respective MCL

concentrations, yet dichloromethane has a significantly smaller percentage of population served

by systems with detections greater than the MCL concentration (1.298%) than does 

trichloroethylene (5.264%).

Inorganic Chemicals

One occurrence measure is the percentage of systems with at least one sample detection 

of a contaminant. Using this measure to assess the regulated IOCs wide range of occurrence was 

found. Percentages ranged from a high of 79.276% of systems with at least one fluoride 

detection to a low of 3.117% of systems with at least one beryllium detection. The five highest 

occurring IOCs based on the percent of systems with detections were fluoride (79.276%), barium 

(72.020%), nitrate (69.942%), arsenic (37.329%), and chromium (24.209%).

A related but different Stage 1 measure, a preliminary estimate of potential drinking 

water exposure to a contaminant, is the percent of the population served by systems with at least 

one sample detection of a particular contaminant. Based on this measure, the five IOCs with the 

highest rates of occurrence/potential exposure are fluoride (with 94.425% of the population 

served by systems with at least one reported detection), nitrate (90.952%), barium (79.473%), 

arsenic (49.309%), and nitrite (44.615%).

In addition to characterizing the rates of contaminant occurrence, the Stage 1 analysis can 

provide information regarding the degree of contaminant occurrence with assessments relative to 

an important health concentration threshold such as a contaminant’s MCL concentration. For 

IOCs, the percentage of systems with at least one sample detection greater than a contaminant’s 

MCL concentration ranged from a high of 2.487% for nitrate to a low of 0.088% for chromium.

The five IOCs with the highest Stage 1 estimated occurrence relative to the MCL concentration 

are nitrate (2.487%), fluoride (1.068%), arsenic (0.750%), nitrite (0.736%) and cadmium 

(0.274%).

A preliminary estimate of drinking water exposure relative to each contaminant’s 

drinking water standard is given by the percentage of the population served by systems with at 

least one sample detection greater than a contaminant’s MCL concentration. Using this measure, 

the five regulated IOCs with the highest occurrence/potential exposure are nitrate (7.310% of the 

population served by systems with at least one detection greater than the nitrate MCL

concentration), nitrite (4.840%), antimony (1.505%), beryllium (1.386%), and arsenic (1.240%).
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Synthetic Organic Chemicals

This same set of occurrence measures was used to assess the regulated SOCs (Exhibits 6-

1 and 6-2). Based on the percentage of systems with at least one sample detection of a 

contaminant, SOC occurrence ranged from a high of 11.197% of systems with at least one di(2-

ethylhexyl)phthalate detection to a low of 0.132% of systems with at least one toxaphene 

detection. The five highest occurring regulated SOCs based on the percent of systems with 

detections were di(2-ethylhexyl)phthalate (11.197%), atrazine (2.386%), dalapon (1.828%), di(2-

ethylhexyl)adipate (1.754%), and 1,2-dibromo-3-chloropropane (1.029%). The high occurrence 

of di(2-ethylhexyl)phthalate could be due, in part, to sample contamination from older generation 

laboratory and field sampling equipment made of plastics that contained (and sometimes 

released) phthalates.

Based on the related but different Stage 1 measure of potential exposure, the percent of 

the population served by systems with at least one sample detection, the five SOCs with the 

highest rates of occurrence/potential exposure are di(2-ethylhexyl)phthalate (with 25.227% of 

the population served by systems with at least one detection), atrazine (17.077%), simazine 

(10.641%), 1,2-dibromo-3-chloropropane (9.268%), and 2,4-dichlorophenoxyacetic acid 

(8.714%).

Based on the assessment of the percent of systems with at least one sample detection 

greater than a contaminant’s MCL concentration, the regulated SOCs ranged from a high of 

1.663% for di(2-ethylhexyl)phthalate to a low of 0.000% (no systems) for carbofuran, diquat, 

glyphosate, hexachlorocyclopentadiene, methoxychlor, picloram, and silvex. The five SOCs with 

the highest Stage 1 estimated occurrence by system relative to the MCL concentration are di(2-

ethylhexyl)phthalate (1.663%), 1,2-dibromo-3-chloropropane (0.388%), atrazine (0.263%), 

ethylene dibromide (0.243%), and benzo(a)pyrene (0.049%).

Based on the percentage of the population served by systems with at least one sample 

detection greater than a contaminant’s MCL concentration, the five SOCs with the highest 

occurrence/ potential exposure are di(2-ethylhexyl)phthalate (6.397%), 1,2-dibromo-3-

chloropropane (1.627%), atrazine (1.551%), ethylene dibromide (1.201%), and benzo(a)pyrene 

(0.117%).

Volatile Organic Chemicals

This same set of occurrence measures was also used to assess the regulated VOCs

(Exhibits 6-1 and 6-2). Based on the percentage of systems with at least one sample detection of 

a contaminant, VOC occurrence ranged from a high of 7.592% of systems with at least one 

xylene detection to a low of 0.179% of systems with at least one 1,1,2-trichloroethane detection.

The five highest occurring regulated VOCs based on the percent of systems with detections were 

xylenes (7.592%), toluene (5.764%), ethylbenezene (3.909%), dichloromethane (3.903%), and 

tetrachloroethylene (2.502%).

Based on the related but different Stage 1 measure of the percent of the population served

by systems with at least one sample detection, the five VOCs with the highest rates of 

occurrence/potential exposure are xylenes (with 17.480% of the population served by systems 
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with at least one xylene detection), dichloromethane (16.542%), tetrachloroethylene (14.076%), 

toluene (13.215%), and trichloroethylene (13.018%).

Based on the assessment of the percent of systems with at least one sample detection 

greater than a contaminant’s MCL concentration, the regulated VOCs ranged from a high of 

0.478% for tetrachloroethylene to a low of 0.000% for six contaminants (1,2-dichlorobenzene; 

trans-1,2-dichloroethylene; ethylbenzene; monochlorobenzene; 1,2,4-trichlorobenzene, and; 

xylenes). The five VOCs with the highest Stage 1 estimated occurrence by system relative to the 

MCL concentration are tetrachloroethylene (0.478%), trichloroethylene (0.387%), 

dichloromethane (0.293%), benzene (0.125%) and carbon tetrachloride (0.113%).

Finally, based on the percentage of the population served by systems reporting at least 

one sample detection greater than a contaminant’s MCL concentration, a preliminary estimate of 

drinking water exposure at or above each contaminant’s drinking water standard, the five VOCs 

with the highest occurrence/potential exposure are tetrachloroethylene (6.448%), 

trichloroethylene (5.264%), 1,1-dichloroethylene (2.517%), carbon tetrachloride (2.189%), and 

dichloromethane (1.298%).

Radionuclides

This same set of occurrence measures was also used to assess the regulated radionuclides 

(Exhibits 6-1 and 6-2). Based on the percentage of systems with at least one sample detection of 

a contaminant, radionuclide occurrence ranged from a high of 74.513% of systems with at least 

one detection of beta particles to a low of 62.188% of systems with at least one combined 

radium-226/-228 detection (pre-December 2003). Based on the related but different Stage 1 

measure of the percent of the population served by systems with at least one sample detection, 

the rates of occurrence/potential exposure for the radionuclides are as follows: beta particles 

(with 86.861% of the population served by systems with at least one beta particle detection), 

uranium (77.256%), combined radium-226/-228 (71.796% pre-December 2003 and 56.754% 

post-December 2003), and alpha particles (68.542%).

Based on the assessment of the percent of systems with at least one sample detection 

greater than a contaminant’s MCL concentration, the regulated radionuclides ranged from a high 

of 11.456% for combined radium-226/-228 (pre-December 2003) to a low of 0.527% for beta 

particles. Based on the percentage of the population served by systems reporting at least one 

sample detection greater than a contaminant’s MCL concentration (a preliminary estimate of 

drinking water exposure at or above each contaminant’s drinking water standard), the 

occurrence/potential exposure for the radionuclides are as follows: uranium (11.884%), 

combined radium-226/-228 (9.620% pre-December 2003 and 9.201% post-December 2003), 

alpha particles (6.208%), and beta particles (1.228%).
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Exhibit 6-1. Summary of Stage 1 Contaminant Occurrence Findings – Systems 

and Population Served by Systems

Contaminant

Systems With 

Detections 

Population Served 

by Systems With 

Detections  Range of Detected 

Concentrations

Number Percent Number Percent

Inorganic Chemicals

Antimony 2,930 5.978% 42,882,761 19.208% 0.000041 - 0.062 mg/L

Arsenic 18,468 37.329% 113,605,034 49.309% 0.000058 - 0.759 mg/L

Asbestos 268 3.237% 13,919,689 16.345% 0.008 - 2,494 MFL

Barium 35,380 72.020% 182,610,220 79.473% 0.000086 - 19 mg/L

Beryllium 1,497 3.117% 30,507,036 13.780% 0.000021 - 0.14 mg/L

Cadmium 2,742 5.605% 38,915,670 16.943% 0.000006 - 0.085 mg/L

Chromium (Total) 11,840 24.209% 94,666,150 41.226% 0.000009 - 5.2 mg/L

Cyanide 1,329 4.144% 28,313,375 17.428% 0.0009 - 1.93 mg/L

Fluoride 38,528 79.276% 220,548,542 94.425% 0.00006 - 38 mg/L

Mercury (Inorganic) 1,937 3.964% 46,091,272 20.052% 0.000021 - 0.104 mg/L

Nitrate (as N) 83,606 69.942% 208,741,341 90.952% 1.04E-06 - 99 mg/L

Nitrite (as N) 19,263 22.318% 92,793,425 44.615% 0.000001 - 13 mg/L

Selenium 8,456 17.284% 85,160,808 37.048% 0.00006 - 0.49 mg/L

Thallium 1,709 3.493% 28,197,102 12.626% 0.00003 - 0.091 mg/L

Synthetic Organic Chemicals

Alachlor 121 0.328% 7,997,150 4.053% 0.01 - 14 μg/L

Atrazine 888 2.386% 34,217,212 17.077% 0.00037 - 27 μg/L

Benzo(a)pyrene 140 0.490% 9,311,608 5.057% 0.007 - 1 μg/L

Carbofuran 45 0.145% 5,568,955 3.315% 0.23 - 8 μg/L

Chlordane 67 0.210% 3,417,785 1.878% 0.005 - 5.4 μg/L

Dalapon 519 1.828% 13,583,043 7.623% 0.01 - 1,210 μg/L

Di(2-ethylhexyl)adipate (DEHA) 507 1.754% 12,459,912 6.767% 0.01 - 1,300 μg/L

Di(2-ethylhexyl)phthalate (DEHP) 3,098 11.197% 45,395,007 25.227% 0.05 - 250 μg/L

1,2-Dibromo-3-chloropropane 

(DBCP) 387 1.029% 17,955,940 9.268% 0.0014 - 10.805 μg/L

2,4-Dichlorophenoxyacetic acid

(2,4-D) 299 0.901% 16,334,821 8.714% 0.009 - 230 μg/L
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Contaminant

Systems With 

Detections 

Population Served 

by Systems With 

Detections  Range of Detected 

Concentrations

Number Percent Number Percent

Dinoseb 87 0.266% 5,646,930 3.087% 0.0355 - 45 μg/L

Diquat 69 0.442% 8,558,497 7.095% 0.08 - 13 μg/L

Endothall 33 0.233% 6,114,200 5.158% 0.1 - 548.1 μg/L

Endrin 47 0.143% 6,951,834 3.777% 0.001 - 3.3 μg/L

Ethylene Dibromide (EDB) 195 0.538% 13,028,187 6.924% 0.001387 - 1.6 μg/L

Glyphosate 29 0.177% 3,542,382 3.047% 2.6 - 700 μg/L

Heptachlor 263 0.796% 8,548,973 4.635% 0.001 - 0.5 μg/L

Heptachlor Epoxide 73 0.221% 3,896,528 2.112% 0.001 - 2 μg/L

Hexachlorobenzene 112 0.341% 3,932,601 2.136% 0.002 - 10 μg/L

Hexachlorocyclopentadiene 225 0.686% 15,372,168 8.321% 0.001 - 15 μg/L

Lindane (gammaHexachlorocyclohexane) 84 0.253% 7,579,836 4.048% 0.001 - 0.69 μg/L

Methoxychlor 53 0.159% 5,546,555 2.956% 0.0073 - 1.1 μg/L

Oxamyl (Vydate) 71 0.230% 6,279,825 3.752% 0.18 - 531.1 μg/L

Pentachlorophenol 251 0.731% 9,703,607 5.094% 0.01 - 10 μg/L

Picloram 136 0.413% 8,526,791 4.575% 0.01 - 190 μg/L

Polychlorinated biphenyls (PCBs) 29 0.158% 3,678,868 2.964% 0.057 - 1.44 μg/L

Simazine 267 0.725% 20,962,003 10.641% 0.01 - 12.4 μg/L

Toxaphene 40 0.132% 3,538,487 2.211% 0.04 - 6.8 μg/L

2,3,7,8-TCDD (Dioxin) 17 0.713% 307,540 0.582% 0.000001 - 0.000178 μg/L

2,4,5-Trichlorophenoxypropionic 

Acid (Silvex) 78 0.237% 4,755,587 2.599% 0.0147 - 28 μg/L

Volatile Organic Chemicals

Benzene 446 0.884% 12,191,524 5.372% 0.031 - 93 μg/L

Carbon Tetrachloride 650 1.289% 22,309,062 9.831% 0.003 - 300 μg/L

1,2-Dichlorobenzene 116 0.230% 3,735,111 1.646% 0.004 - 110 μg/L

1,4-Dichlorobenzene 748 1.497% 7,463,993 3.325% 0.002 - 700 μg/L

1,2-Dichloroethane 376 0.745% 14,019,067 6.178% 0.005 - 135.8 μg/L

1,1-Dichloroethylene 347 0.688% 13,426,923 5.917% 0.054 - 214 μg/L
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Contaminant

Systems With 

Detections 

Population Served 

by Systems With 

Detections  Range of Detected 

Concentrations

Number Percent Number Percent

cis-1,2-Dichloroethylene 485 0.964% 19,038,241 8.438% 0.008 - 220 μg/L

trans-1,2-Dichloroethylene 95 0.189% 3,096,479 1.372% 0.025 - 24 μg/L

Dichloromethane 

(Methylene Chloride) 1,958 3.903% 37,524,772 16.542% 0.0041 - 315.9 μg/L

1,2-Dichloropropane 242 0.480% 10,172,188 4.483% 0.005 - 26.2 μg/L

Ethylbenzene 1,972 3.909% 26,908,998 11.857% 0.002 - 557 μg/L

Monochlorobenzene 135 0.268% 3,529,759 1.564% 0.003 - 42 μg/L

Styrene 528 1.047% 5,685,948 2.506% 0.002 - 710 μg/L

Tetrachloroethylene (PCE) 1,262 2.502% 31,952,900 14.076% 0.001 - 177 μg/L

Toluene 2,908 5.764% 29,991,392 13.215% 0.002 - 5,100 μg/L

1,2,4-Trichlorobenzene 161 0.321% 2,016,307 0.889% 0.003 - 70 μg/L

1,1,1-Trichloroethane 542 1.075% 14,883,555 6.559% 0.009 - 1,400 μg/L

1,1,2-Trichloroethane 90 0.179% 2,060,549 0.908% 0.015 - 40 μg/L

Trichloroethylene (TCE) 1,013 2.009% 29,537,747 13.018% 0.001 - 159 μg/L

Vinyl Chloride 207 0.411% 3,528,685 1.558% 0.013 - 46.5 μg/L

Xylenes (Total) 3,621 7.592% 38,118,213 17.480% 0.002 - 4,000 μg/L

Radiological Contaminants

Alpha Particles 12,699 68.080% 83,052,912 68.542% 8E-10 - 348.33 pCi/L

Beta Particles 10,604 74.513% 104,471,857 86.861% 0.00001 - 488 pCi/L

Combined Radium-226 & -228

(original Radionuclides rule) 4,281 62.188% 34,047,514 71.796% 0.01 - 142 pCi/L

Combined Radium-226 & -228

(revised Radionuclides rule) 2,724 69.972% 23,511,235 56.754% 0.0008 - 56.66 pCi/L

Uranium 4,101 69.262% 54,566,649 77.256% 1.49E-06 - 469 μg/L
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Exhibit 6-2. Number and Percent of Systems and Population Served by Systems 

with Detections Greater than the MCL Concentration

Contaminant

(MCL Concentration)

Systems With 

Detections > MCL Concentration

Population Served by Systems With 

Detections > MCL Concentration

Number Percent Number Percent

Inorganic Chemicals

Antimony

(0.006 mg/L) 130 0.265% 3,360,506 1.505%

Arsenic1

(0.05 mg/L) 371 0.750% 2,855,848 1.240%

Asbestos

(7 MFL) 14 0.169% 253,977 0.298%

Barium

(2 mg/L) 66 0.134% 211,108 0.092%

Beryllium

(0.004 mg/L) 53 0.110% 3,067,277 1.386%

Cadmium

(0.005 mg/L) 134 0.274% 2,399,069 1.045%

Chromium (Total)

(0.1 mg/L) 43 0.088% 716,617 0.312%

Cyanide

(0.2 mg/L) 44 0.137% 256,908 0.158%

Fluoride

(4 mg/L) 519 1.068% 2,823,214 1.209%

Mercury (Inorganic)

(0.002 mg/L) 82 0.168% 2,591,320 1.127%

Nitrate (as N)

(10 mg/L) 2,973 2.487% 16,777,093 7.310%

Nitrite (as N)

(1 mg/L) 635 0.736% 10,067,031 4.840%

Selenium

(0.05 mg/L) 65 0.133% 224,816 0.098%

Thallium

(0.002 mg/L) 125 0.255% 1,831,801 0.820%

Synthetic Organic Chemicals

Alachlor

(2 μg/L) 8 0.022% 25,419 0.013%

Atrazine

(3 μg/L) 98 0.263% 3,108,330 1.551%

Benzo(a)pyrene

(0.2 μg/L) 14 0.049% 214,983 0.117%

Carbofuran

(40 μg/L) 0 0.000% 0 0.000%

Chlordane

(2 μg/L) 4 0.013% 625 0.000%

Dalapon

(200 μg/L) 1 0.004% 20,114 0.011%

Di(2-ethylhexyl)adipate (DEHA)

(400 μg/L) 2 0.007% 22,913 0.012%

Di(2-ethylhexyl)phthalate (DEHP)

(6 μg/L) 460 1.663% 11,510,704 6.397%
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Contaminant

(MCL Concentration)

Systems With 

Detections > MCL Concentration

Population Served by Systems With 

Detections > MCL Concentration

Number Percent Number Percent

1,2-Dibromo-3-chloropropane 

(DBCP) (0.2 μg/L) 146 0.388% 3,151,491 1.627%

2,4-Dichlorophenoxyacetic acid

(70 μg/L) 1 0.003% 13,933 0.007%

Dinoseb

(7 μg/L) 5 0.015% 26,212 0.014%

Diquat

(20 μg/L) 0 0.000% 0 0.000%

Endothall

(100 μg/L) 3 0.021% 74,657 0.063%

Endrin

(2 μg/L) 1 0.003% 300 0.000%

Ethylene Dibromide (EDB)

(0.05 μg/L) 88 0.243% 2,260,060 1.201%

Glyphosate

(700 μg/L) 0 0.000% 0 0.000%

Heptachlor

(0.4 μg/L) 2 0.006% 4,699 0.003%

Heptachlor Epoxide

(0.2 μg/L) 6 0.018% 19,347 0.010%

Hexachlorobenzene

(1 μg/L) 4 0.012% 4,944 0.003%

Hexachlorocyclopentadiene

(50 μg/L) 0 0.000% 0 0.000%

Lindane (gammaHexachlorocyclohexane) (0.2 μg/L) 3 0.009% 4,836 0.003%

Methoxychlor

(40 μg/L) 0 0.000% 0 0.000%

Oxamyl (Vydate)

(200 μg/L) 1 0.003% 200 0.000%

Pentachlorophenol

(1 μg/L) 8 0.023% 11,805 0.006%

Picloram

(500 μg/L) 0 0.000% 0 0.000%

Polychlorinated biphenyls (PCBs)

(0.5 μg/L) 2 0.011% 125,046 0.101%

Simazine

(4 μg/L) 16 0.043% 123,159 0.063%

Toxaphene

(3 μg/L) 5 0.016% 27,063 0.017%

2,3,7,8-TCDD (Dioxin)

(0.00003 μg/L) 1 0.042% 7,100 0.013%

2,4,5-Trichlorophenoxypropionic 

Acid (Silvex) (50 μg/L) 0 0.000% 0 0.000%

Volatile Organic Chemicals

Benzene

(5 μg/L) 63 0.125% 486,938 0.215%

Carbon Tetrachloride

(5 μg/L) 57 0.113% 4,967,564 2.189%

1,2-Dichlorobenzene

(600 μg/L) 0 0.000% 0 0.000%

1,4-Dichlorobenzene

(75 μg/L) 3 0.006% 99,019 0.044%
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Contaminant

(MCL Concentration)

Systems With 

Detections > MCL Concentration

Population Served by Systems With 

Detections > MCL Concentration

Number Percent Number Percent

1,2-Dichloroethane

(5 μg/L) 36 0.071% 438,212 0.193%

1,1-Dichloroethylene

(7 μg/L) 33 0.065% 5,712,193 2.517%

cis-1,2-Dichloroethylene

(70 μg/L) 5 0.010% 166,753 0.074%

trans-1,2-Dichloroethylene

(100 μg/L) 0 0.000% 0 0.000%

Dichloromethane (Methylene 

Chloride) (5 μg/L) 147 0.293% 2,943,449 1.298%

1,2-Dichloropropane

(5 μg/L) 10 0.020% 351,687 0.155%

Ethylbenzene

(700 μg/L) 0 0.000% 0 0.000%

Monochlorobenzene

(100 μg/L) 0 0.000% 0 0.000%

Styrene

(100 μg/L) 4 0.008% 1,310 0.001%

Tetrachloroethylene (PCE)

(5 μg/L) 241 0.478% 14,637,946 6.448%

Toluene

(1,000 μg/L) 1 0.002% 500 0.000%

1,2,4-Trichlorobenzene

(70 μg/L) 0 0.000% 0 0.000%

1,1,1-Trichloroethane

(200 μg/L) 2 0.004% 226 0.000%

1,1,2-Trichloroethane

(5 μg/L) 7 0.014% 126,351 0.056%

Trichloroethylene (TCE)

(5 μg/L) 195 0.387% 11,945,084 5.264%

Vinyl Chloride

(2 μg/L) 41 0.081% 482,079 0.213%

Xylenes (Total) 

(10,000 μg/L) 0 0.000% 0 0.000%

Radiological Contaminants

Alpha Particles

(15 pCi/L) 854 4.578% 7,522,810 6.208%

Beta Particles

(screening level = 50 pCi/L) 75 0.527% 1,477,336 1.228%

Combined Radium-226 & -228

(original Radionuclides rule)

(5 pCi/L)

502 7.292% 4,562,001 9.620%

Combined Radium-226 & -228

(revised Radionuclides rule)

(5 pCi/L)

446 11.456% 3,811,454 9.201%

Uranium

(30 μg/L) 448 7.566% 8,394,113 11.884%
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6.2 Comparison of Stage 1 Analysis of First and Second Six-Year Reviews

Exhibit 6-3 presents a comparison of contaminant occurrence estimates from the first SixYear Review, based on compliance monitoring data from 1993-1997, and the second Six-Year 

Review, based on compliance monitoring data from 1998-2005. Some of the contaminants 

assessed for the second Six-Year Review were not assessed for the first Six-Year Review. The 

occurrence estimates from the first Six-Year Review and the second Six-Year Review appear to 

be broadly similar. Note, however, that comparisons or apparent occurrence changes over time 

must be somewhat qualified given the differences between the two datasets. The first Six-Year 

Review dataset consisted of data from 16 states that were assembled into a “national crosssection” that was indicative, though not statistically representative, of national occurrence. In 

contrast, the second Six-Year Review-ICR Dataset consists of data from 45 states that serve as a 

very large sample that, essentially, is nationally representative. Therefore, it is possible that 

differences in occurrence measures between the first and second Six-Year Review Stage 1 

findings summarized in Exhibit 6-3 reflect differences in the respective datasets rather than 

differences in actual occurrence. Nonetheless, both datasets provided sound assessments of 

national contaminant occurrence in systems, so significant differences in occurrence estimates 

generated for the first and second Six-Year Reviews may provide information on changes in 

occurrence over time. Occurrence evaluations specifically designed to assess occurrence trends 

over time might assess occurrence changes for a particular contaminant only in all the systems 

that were included in both the first and second Six-Year Review datasets. These temporal 

analyses of contaminant occurrence were not conducted for this current assessment.

Exhibit 6-3. Comparison of Stage 1 Analyses of the First Six-Year Review and the 

Second Six-Year Review based on the Percent of Systems

Contaminant 

(MCL Concentration)

Percent of Systems 

With Detections 

Percent of Systems 

With Detections 

> MCL Concentration

Six-Year 11 Six-Year 2 Six-Year 11 Six-Year 2

Inorganic Chemicals

Antimony

(0.006 mg/L) 14.4% 5.98% 0.62% 0.27%

Barium

(2 mg/L) 71.2% 72.02% 0.17% 0.13%

Beryllium

(0.004 mg/L) 3.32% 3.12% 0.22% 0.11%

Cadmium

(0.005 mg/L) 17.6% 5.61% 0.54% 0.27%

Chromium (Total)

(0.1 mg/L) 18.3% 24.21% 0.13% 0.09%

Cyanide

(0.2 mg/L) 17.0% 4.14% 0.17% 0.14%

Fluoride

(4 mg/L) 83.8% 79.28% 1.28% 1.07%

Mercury (Inorganic)

(0.002 mg/L) 17.3% 3.96% 0.26% 0.17%

Selenium

(0.05 mg/L) 22.1% 17.28% 0.11% 0.13%
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Contaminant 

(MCL Concentration)

Percent of Systems 

With Detections 

Percent of Systems 

With Detections 

> MCL Concentration

Six-Year 11 Six-Year 2 Six-Year 11 Six-Year 2

Thallium

(0.002 mg/L) 4.22% 3.49% 0.68% 0.26%

Synthetic Organic Chemicals

Alachlor

(2 μg/L) 0.67% 0.33% 0.00% 0.02%

Atrazine

(3 μg/L) 3.83% 2.39% 0.68% 0.26%

Benzo(a)pyrene

(0.2 μg/L) 0.44% 0.49% 0.05% 0.05%

Carbofuran

(40 μg/L) 0.06% 0.14% 0.00% 0.00%

Chlordane

(2 μg/L) 1.19% 0.21% 0.01% 0.01%

Dalapon

(200 μg/L) 1.10% 1.83% 0.00% 0.00%

Di(2-ethylhexyl)adipate (DEHA)

(400 μg/L) 7.31% 1.75% 0.01% 0.01%

Di(2-ethylhexyl)phthalate (DEHP)

(6 μg/L) 12.5% 11.20% 2.20% 1.66%

1,2-Dibromo-3-chloropropane (DBCP)

(0.2 μg/L) 1.61% 1.03% 0.91% 0.39%

2,4-Dichlorophenoxyacetic acid (2,4-D)

(70 μg/L) 0.12% 0.90% 0.02% 0.00%

Dinoseb

(7 μg/L) 0.24% 0.27% 0.02% 0.02%

Diquat

(20 μg/L) 0.49% 0.44% 0.02% 0.00%

Endothall

(100 μg/L) 0.15% 0.23% 0.03% 0.02%

Endrin

(2 μg/L) 0.18% 0.14% 0.02% 0.00%

Ethylene Dibromide (EDB) 

(0.05 μg/L) 1.06% 0.54% 0.72% 0.24%

Glyphosate

(700 μg/L) 0.10% 0.18% 0.00% 0.00%

Heptachlor

(0.4 μg/L) 0.08% 0.80% 0.01% 0.01%

Heptachlor Epoxide

(0.2 μg/L) 0.09% 0.22% 0.03% 0.02%

Hexachlorobenzene

(1 μg/L) 0.09% 0.34% 0.01% 0.01%

Hexachlorocyclopentadiene

(50 μg/L) 0.89% 0.69% 0.00% 0.00%

Lindane (gamma-Hexachlorocyclohexane)

(0.2 μg/L) 0.16% 0.25% 0.04% 0.01%

Methoxychlor

(40 μg/L) 0.19% 0.16% 0.01% 0.00%

Oxamyl (Vydate)

(200 μg/L) 0.08% 0.23% 0.00% 0.00%

Pentachlorophenol

(1 μg/L) 0.43% 0.73% 0.03% 0.02%

Picloram

(500 μg/L) 0.41% 0.41% 0.00% 0.00%
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Contaminant 

(MCL Concentration)

Percent of Systems 

With Detections 

Percent of Systems 

With Detections 

> MCL Concentration

Six-Year 11 Six-Year 2 Six-Year 11 Six-Year 2

Polychlorinated biphenyls (PCBs)

(0.5 μg/L) 0.09% 0.16% 0.03% 0.01%

Simazine

(4 μg/L) 1.80% 0.72% 0.06% 0.04%

Toxaphene

(3 μg/L) 0.08% 0.13% 0.01% 0.02%

2,4,5-Trichlorophenoxypropionic Acid

(Silvex) (50 μg/L) 0.40% 0.24% 0.00% 0.00%

Volatile Organic Chemicals

Benzene

(5 μg/L) 1.31% 0.88% 0.19% 0.12%

Carbon Tetrachloride

(5 μg/L) 1.99% 1.29% 0.20% 0.11%

1,2-Dichlorobenzene

(600 μg/L) 0.61% 0.23% 0.00% 0.00%

1,4-Dichlorobenzene

(75 μg/L) 1.76% 1.50% 0.00% 0.01%

1,2-Dichloroethane

(5 μg/L) 1.31% 0.75% 0.13% 0.07%

1,1-Dichloroethylene

(7 μg/L) 1.58% 0.69% 0.24% 0.07%

cis-1,2-Dichloroethylene

(70 μg/L) 1.37% 0.96% 0.03% 0.01%

trans-1,2-Dichloroethylene

(100 μg/L) 0.53% 0.19% 0.00% 0.00%

Dichloromethane (Methylene Chloride)

(5 μg/L) 8.59% 3.90% 0.67% 0.29%

1,2-Dichloropropane

(5 μg/L) 0.67% 0.48% 0.07% 0.02%

Ethylbenzene

(700 μg/L) 3.62% 3.91% 0.00% 0.00%

Monochlorobenzene

(100 μg/L) 0.75% 0.27% 0.00% 0.00%

Styrene

(100 μg/L) 0.99% 1.05% 0.00% 0.01%

Tetrachloroethylene (PCE)

(5 μg/L) 3.36% 2.50% 0.78% 0.48%

Toluene

(1,000 μg/L) 4.73% 5.76% 0.00% 0.00%

1,2,4-Trichlorobenzene

(70 μg/L) 0.61% 0.32% 0.00% 0.00%

1,1,1-Trichloroethane

(200 μg/L) 2.50% 1.07% 0.01% 0.00%

1,1,2-Trichloroethane

(5 μg/L) 0.62% 0.18% 0.04% 0.01%

Trichloroethylene (TCE)

(5 μg/L) 2.61% 2.01% 0.65% 0.39%

Vinyl Chloride

(2 μg/L) 0.61% 0.41% 0.11% 0.08%

Xylenes (Total)

(10,000 μg/L) 4.16% 7.59% 0.00% 0.00%

1. The first Six-Year Review occurrence estimate values presented in this table are from the report titled Occurrence 

Estimation Methodology and Occurrence Findings for Six-Year Review of National Primary Drinking Water 

Regulations. EPA Report 815-R-03-006, Office of Water (USEPA, 2003b).
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6.3 System Sample Point Level Analysis

The basic Stage 1 analytical methodology is a conservative approach; occurrence 

measures are based on simple counts of whether or not a system has at least one monitoring 

sample identified with a contaminant detection greater than a specified concentration threshold.

The approach includes another implicit conservative assumption; if a detection is found in a 

single entry point to the distribution system or other formal system sample point (SP), then the 

entire population served by the system is assumed to be potentially exposed to the detected 

contaminant at the system. For example, if a system serves a population of 30,000 and identified 

a detection of a contaminant in one of its two SPs, the primary Stage 1 analytical methodology 

would estimate that the entire population served by the system (30,000) was potentially exposed 

to the maximum detected levels of the contaminant found in the one SP. In this context, sample 

points (SPs) are defined as the authorized drinking water sample locations for compliance 

monitoring of regulated contaminants. SPs primarily are entry points to the distribution system, 

but a small number of states allow for sampling of raw, untreated ground water wells or surface 

water intakes as well.

In reality, many systems get water from multiple water sources, such as a mix of 

purchased and non-purchased water, ground water wells and surface water source intakes, etc. In 

systems with multiple SPs, such as multiple surface water intakes, multiple wells, and/or 

multiple entry points to the distribution system, contaminant occurrence in one source or one SP 

does not necessarily mean contaminant occurrence in all sources or SPs that distribute water to 

consumers. Given this, additional Stage 1 analyses were conducted at the SP-level to provide 

supplementary details of contaminant occurrence.

The SP analysis is a less conservative estimate of the population served by systems with 

contaminant detections. To derive this SP-level measure, an assumption was necessary regarding 

population served by individual SPs at drinking water systems. The population served by each 

SP, and entry point to the distribution system, at a system is often difficult to know and is rarely, 

if ever, reported along with other compliance monitoring records. Therefore, EPA assumed for 

the analysis that the total population served by a particular system is equally distributed across 

all SPs at the system.14 With this assumption, the population served by a SP with a detection of a 

particular contaminant is calculated by multiplying the system’s total population served by the 

portion of that system’s SPs with a contaminant detection. For example, if a system serves a 

population of 30,000 and found detections of a contaminant in one of its two SPs, then a 

population of 15,000 (30,000 x 1⁄2) would be estimated to be potentially exposed to the 

contaminant.

This sample point analysis required determination of the total number of entry points 

and/or other SPs for each system. This was done by counting the total number of unique SPs for 

14 This “proportional population” assumption is based on the idea that for every public water system, each sample 

point serves an equal portion of the system’s total population. How well this assumption reflects actual populations 

potentially exposed to contaminant occurrence at a system will depend on the distribution system and service 

population configurations at individual systems.
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each system over the entire eight years of data. These counts were done separately for each 

contaminant at every system. While conducting these counts, it appeared that some systems may 

have changed their sample point numbering conventions, their “SP identification codes,” the 

formal sample point identification number, at some point over the eight years of data, which 

would result in the number of apparent sample points being higher than the number of actual 

sample points. If so, this approach to sample point counting could potentially overestimate the 

total number of SPs for a system thereby resulting in an underestimate of the population served 

by each SP.15

Exhibit 6-4 presents a summary of the Stage 1 findings based on SPs and population 

served by SPs. Similar to the system-level analysis for the IOCs, fluoride and barium had the 

highest percentage of SPs (78.424% and 67.150%, respectively) with detections at or above the 

MRL. The largest percentage of the population served by SPs with detections at or above the 

MRL was for fluoride (91.005%). Of all the IOCs, nitrate had the highest percent of SPs with 

detections greater than the MCL concentration (2.072%).

Di(2-ethylhexyl)phthalate was the highest occurring SOC based on the percent of SPs

with detections at or above the MRL (8.726%). Atrazine and di(2-ethylhexyl)phthalate had the 

highest percentages of population served by SPs with detections at or above the MRL (13.042 % 

and 12.451%, respectively). In addition, di(2-ethylhexyl)phthalate had the highest percent of SPs 

with detections greater than the MCL concentration of all the SOCs (1.071%). The high 

occurrence of di(2-ethylhexyl)phthalate could be due, in part, to sample contamination from 

older generation laboratory and field sampling equipment made of plastics that contained (and 

sometimes released) phthalates.

Similar to the system-level analysis, total xylenes was the highest occurring VOC, based 

on the percent of SPs with detections at or above the MRL, with 5.386% of SPs detecting. Of all 

the VOCs, tetrachloroethylene and trichloroethylene had the highest percent of SPs with 

detections greater than the MCL concentration (0.522% and 0.473%, respectively) and 

population served by SPs with detections greater than the MCL concentration (1.212% and 

1.452%, respectively).

Uranium was the highest occurring radionuclide, based on the percent of SPs with 

detections at or above the MRL, with 69.796% of SPs detecting. Combined radium-226/-228 had 

the highest percent of SPs with detections greater than the MCL concentration (7.239% preDecember 2003 and 11.329% post-December 2003) and population served by SPs with 

detections greater than the MCL concentration (4.784% pre-December 2003 and 4.729% postDecember 2003).

15 Another method was explored for counting the number of SPs. This other method used the maximum number of 

SPs that sampled in a given year as the system’s “total number of SPs.” This approach likely avoids the issue of 

changing SP numbering conventions over time. However, this method has the potential to underestimate the total 

number of SPs for the system and therefore overestimate the population-served by each SP. For example, a system 

could truly have a total of three SPs but those three SPs might not all sample within the same year, so the number of 

actual SPs sampled over the eight-year period might be underestimated. If a system is on reduced monitoring, each 

SP might only need to sample as often as once every three years.
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Exhibit 6-4. Summary of Stage 1 Contaminant Occurrence Findings – Sample 

Points and Population Served by Sample Points

Contaminant 

(MCL Concentration)

Percent of Sample Points Percent of PopulationServed by Sample Points 

With 

Detections



With 

Detections

> MCL

Concentration

With 

Detections



With 

Detections

> MCL

Concentration

Inorganic Chemicals

Antimony

(0.006 mg/L) 4.407% 0.189% 11.488% 0.587%

Arsenic

(0.05 mg/L) 37.410% 0.628% 36.759% 0.209%

Asbestos

(7 MFL) 2.426% 0.132% 5.984% 0.118%

Barium

(2 mg/L) 67.150% 0.093% 72.546% 0.052%

Beryllium

(0.004 mg/L) 2.220% 0.074% 7.714% 1.213%

Cadmium

(0.005 mg/L) 3.949% 0.184% 8.687% 0.549%

Chromium (Total)

(0.1 mg/L) 21.720% 0.062% 26.425% 0.038%

Cyanide

(0.2 mg/L) 2.915% 0.081% 10.515% 0.030%

Fluoride

(4 mg/L) 78.424% 0.729% 91.005% 0.276%

Mercury (Inorganic)

(0.002 mg/L) 3.245% 0.102% 7.821% 0.204%

Nitrate (as N)

(10 mg/L) 66.205% 2.072% 84.026% 1.943%

Nitrite (as N)

(1 mg/L) 20.351% 0.671% 26.926% 1.155%

Selenium

(0.05 mg/L) 15.632% 0.099% 23.564% 0.024%

Thallium

(0.002 mg/L) 2.817% 0.179% 7.408% 0.213%

Synthetic Organic Chemicals

Alachlor

(2 μg/L) 0.235% 0.013% 3.736% 0.006%

Atrazine

(3 μg/L) 1.971% 0.160% 13.042% 0.783%

Benzo(a)pyrene

(0.2 μg/L) 0.315% 0.031% 4.235% 0.044%

Carbofuran

(40 μg/L) 0.101% 0.000% 3.111% 0.000%

Chlordane

(2 μg/L) 0.146% 0.011% 1.701% 0.000%

Dalapon

(200 μg/L) 1.276% 0.002% 6.027% 0.011%

Di(2-ethylhexyl)adipate (DEHA)

(400 μg/L) 1.286% 0.006% 4.602% 0.012%

Di(2-ethylhexyl)phthalate (DEHP)

(6 μg/L) 8.726% 1.071% 12.451% 1.436%

1,2-Dibromo-3-chloropropane (DBCP)

(0.2 μg/L) 1.616% 0.518% 5.276% 0.422%
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Contaminant 

(MCL Concentration)

Percent of Sample Points Percent of PopulationServed by Sample Points 

With 

Detections



With 

Detections

> MCL

Concentration

With 

Detections



With 

Detections

> MCL

Concentration

2,4-Dichlorophenoxyacetic acid (2,4-D)

(70 μg/L) 0.630% 0.002% 5.587% 0.007%

Dinoseb

(7 μg/L) 0.183% 0.009% 2.674% 0.003%

Diquat

(20 μg/L) 0.318% 0.000% 2.899% 0.000%

Endothall

(100 μg/L) 0.162% 0.012% 3.837% 0.024%

Endrin

(2 μg/L) 0.105% 0.002% 3.619% 0.000%

Ethylene Dibromide (EDB)

(0.05 μg/L) 0.417% 0.186% 2.265% 0.311%

Glyphosate

(700 μg/L) 0.118% 0.000% 2.749% 0.000%

Heptachlor

(0.4 μg/L) 0.762% 0.004% 3.964% 0.001%

Heptachlor Epoxide

(0.2 μg/L) 0.162% 0.011% 1.937% 0.003%

Hexachlorobenzene

(1 μg/L) 0.220% 0.007% 2.011% 0.003%

Hexachlorocyclopentadiene

(50 μg/L) 0.451% 0.000% 5.573% 0.000%

Lindane (gammaHexachlorocyclohexane) (0.2 μg/L) 0.190% 0.005% 3.690% 0.001%

Methoxychlor

(40 μg/L) 0.110% 0.000% 2.273% 0.000%

Oxamyl (Vydate)

(200 μg/L) 0.152% 0.002% 2.583% 0.000%

Pentachlorophenol

(1 μg/L) 0.503% 0.014% 3.515% 0.002%

Picloram

(500 μg/L) 0.281% 0.000% 3.373% 0.000%

Polychlorinated biphenyls (PCBs)

(0.5 μg/L) 0.131% 0.007% 2.472% 0.025%

Simazine

(4 μg/L) 0.492% 0.026% 7.421% 0.061%

Toxaphene

(3 μg/L) 0.093% 0.010% 2.061% 0.015%

2,3,7,8-TCDD (Dioxin)

(0.00003 μg/L) 0.384% 0.019% 0.182% 0.013%

2,4,5-Trichlorophenoxypropionic Acid

(Silvex) (50 μg/L) 0.166% 0.000% 2.078% 0.000%

Volatile Organic Chemicals

Benzene

(5 μg/L) 0.591% 0.079% 1.333% 0.053%

Carbon Tetrachloride

(5 μg/L) 0.898% 0.073% 4.082% 0.070%

1,2-Dichlorobenzene

(600 μg/L) 0.153% 0.000% 0.685% 0.000%

1,4-Dichlorobenzene

(75 μg/L) 0.956% 0.003% 1.417% 0.001%

1,2-Dichloroethane

(5 μg/L) 0.639% 0.053% 2.300% 0.032%
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Contaminant 

(MCL Concentration)

Percent of Sample Points Percent of PopulationServed by Sample Points 

With 

Detections



With 

Detections

> MCL

Concentration

With 

Detections



With 

Detections

> MCL

Concentration

1,1-Dichloroethylene

(7 μg/L) 0.711% 0.082% 1.540% 0.227%

cis-1,2-Dichloroethylene

(70 μg/L) 1.083% 0.009% 2.701% 0.005%

trans-1,2-Dichloroethylene

(100 μg/L) 0.143% 0.000% 0.479% 0.000%

Dichloromethane (Methylene Chloride)

(5 μg/L) 2.610% 0.180% 5.020% 0.549%

1,2-Dichloropropane

(5 μg/L) 0.320% 0.014% 0.727% 0.080%

Ethylbenzene

(700 μg/L) 2.456% 0.000% 2.175% 0.000%

Monochlorobenzene

(100 μg/L) 0.166% 0.000% 0.725% 0.000%

Styrene

(100 μg/L) 0.632% 0.004% 0.618% 0.000%

Tetrachloroethylene (PCE)

(5 μg/L) 3.189% 0.522% 4.489% 1.212%

Toluene

(1,000 μg/L) 3.606% 0.001% 3.828% 0.000%

1,2,4-Trichlorobenzene

(70 μg/L) 0.182% 0.000% 0.372% 0.000%

1,1,1-Trichloroethane

(200 μg/L) 0.897% 0.002% 1.561% 0.000%

1,1,2-Trichloroethane

(5 μg/L) 0.119% 0.012% 0.386% 0.007%

Trichloroethylene (TCE)

(5 μg/L) 2.426% 0.473% 4.590% 1.452%

Vinyl Chloride

(2 μg/L) 0.281% 0.048% 0.712% 0.124%

Xylenes (Total)

(10,000 μg/L) 5.386% 0.000% 5.457% 0.000%

Radiological Contaminants

Alpha Particles

(15 pCi/L) 62.173% 4.022% 55.651% 1.696%

Beta Particles

(screening level = 50 pCi/L) 68.192% 0.359% 75.894% 0.347%

Combined Radium-226 & -228

(original Radionuclides rule)

(5 pCi/L)

58.091% 7.239% 57.507% 4.784%

Combined Radium-226 & -228

(revised Radionuclides rule)

(5 pCi/L)

66.595% 11.329% 48.258% 4.729%

Uranium

(30 μg/L) 69.796% 6.759% 68.227% 1.922%
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7 Stage 2 Analysis

The Stage 2 statistical analysis consists of estimates of long-term system mean 

concentrations for 11 regulated SOCs and 11 regulated VOCs. These 22 contaminants are 

referred to as “Category 1 contaminants” based on their: relatively high rates of occurrence at or 

near concentration thresholds of concern; new or ongoing heath effects assessments, and; 

potential new laboratory analytical capabilities. These 22 Category 1 contaminants are benzene, 

carbofuran, carbon tetrachloride, chlordane, 1,2-dibromo-3-chloropropane, 1,2-dichloroethane, 

dichloromethane, 2,4-dichlorophenoxyacetic acid, 1,2-dichloropropane, endothall, heptachlor, 

heptachlor epoxide, hexachlorobenzene, hexachlorocyclopentadiene, oxamyl, 

tetrachloroethylene, toluene, toxaphene, 1,1,2-trichloroethane, trichloroethylene, vinyl chloride, 

and xylenes (total).

Because the second Six-Year Review-ICR dataset is so much larger and more robust than 

the dataset used for the for first Six-Year Review, it was possible here to use a simpler analytical 

approach to estimate system means. For the second Six-Year Review, system means were 

calculated using a simple arithmetic average of all detection and non-detection records for each 

system. For the first Six-Year Review, the Stage 2 analysis consisted of Bayesian probabilistic 

modeling to estimate long-term system means and the number of systems with means exceeding 

certain contaminant concentration thresholds. All the first Six-Year Review occurrence analyses, 

including the Stage 2 analysis Bayesian modeling, used occurrence data from the “16-State 

National Cross-Section.” 

The Stage 2 analysis system contaminant mean estimates provide a less conservative 

contaminant occurrence estimate than does the Stage 1 analysis, which is based on a single 

maximum sample result exceeding a certain contaminant threshold. The Stage 2 analyses also 

provide better occurrence estimates for contaminants for which chronic health effects are of 

concern. 

Calculating a contaminant arithmetic mean for each system required substituting a 

numeric value for each non-detection record. This “simple substitution method” for substituting 

numeric values for the non-detections is a straight-forward and standard data management 

approach for this type of analysis (e.g., Helsel and Hirsch, 1991). Public water systems use this 

approach for calculating annual, rolling four-quarter average contaminant concentrations and can 

substitute zero for each sample non-detection record when generating average concentration 

values. For the second Six-Year Review, three different substitution values –zero, one-half the 

MRL value, and the full MRL value– were used to replace each non-detection record. Since the 

true, but unknown, concentration of a contaminant for each non-detection is theoretically 

between zero and the MRL, using a substitution value of zero for each non-detection would 

generate a lower bound estimated average, substituting the full MRL would generate an upper 

bound estimate and substituting the 1⁄2 MRL value would generate a mid-range estimate. EPA 

calculated three arithmetic means for each contaminant at each system using the zero, one-half 

MRL and full MRL substitution values. 

These system contaminant mean calculations were done for all systems with data in the 

Six-Year Review-ICR dataset. Then, all system results were aggregated and the percent of all 
EPA – OGWDW Analysis of Occurrence Data for the Second Six-Year Review of NPDWRs EPA-815-B-09-006

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55 of 59

systems with a long-term mean concentration greater than each contaminant’s MCL 

concentration was calculated. The results from these Stage 2 analyses generated using the zero 

substitution value are presented below in Exhibit 7-1. The results based on the system means 

generated using the zero substitution value are equivalent to how states are authorized to 

calculate system means for compliance determinations. The analogous Stage 2 analytical results 

using the one-half and full MRL values are presented in Appendix B.

7.1 Summary of Occurrence Estimations

The Stage 2 analyses estimates are presented in Exhibit 7-1. For comparison, the Stage 1 

results relative to the MCL concentration are also included. The estimates reflect the percentage 

of systems, and population served by systems, with an estimated system contaminant mean 

exceeding the respective MCL concentration for each contaminant. Note that these occurrence 

measures relative to the MCL concentration are based on the system mean concentration over the 

eight-year period of data in the second Six-Year Review-ICR dataset. Note: This does not 

necessarily indicate an MCL violation. This differs from compliance assessments that calculate a 

system mean concentration over four consecutive quarters. An MCL violation occurs when the 

MCL is exceeded by the average results from four quarterly confirmation samples.

The Stage 2 occurrence estimates indicate a low portion of systems and population served

by systems with long-term contaminant means greater than the MCL concentrations. The five 

contaminants exhibiting the highest Stage 2 occurrence estimates for the percent of systems with 

long-term contaminant means greater than MCL concentration are 1,2-dibromo-3-chloropropane 

(0.112%), trichloroethylene (0.050%), tetrachloroethylene (0.046%), dichloromethane (0.026%), 

and benzene (0.020%). The percent of population served by systems with long-term contaminant 

means greater than MCL concentration, the five highest contaminants are tetrachloroethylene 

(0.277%), trichloroethylene (0.181%), toxaphene (0.014%), 1,2-dibromo-3-chloropropane 

(0.013%), and benzene (0.006%).

Please see Appendix B for additional measures of contaminant occurrence based on the 

Stage 2 analyses, including presentations of the numbers of systems and population served to 

supplement the percent values presented in Exhibit 7-1. The appendix summary tables present 

findings separately for ground water vs. surface water and present occurrence measures that 

identify the total number of systems and total population served by systems with estimated 

system contaminant means greater than the MCL concentration as well as many other thresholds.

Exhibit 7-1. Comparison of Stage 1 and Stage 2 Analytical Results - Percent of 

Systems and Population Served by Systems Greater than the MCL Concentration

Contaminant 

(MCL Concentration)

Percent of Systems 

> MCL Concentration

Percent of Population Served by 

Systems > MCL Concentration

Stage 1 1

(one detect 

> MCL

Concentration)

Stage 2 2

(mean > MCL

Concentration)

Stage 1 1

(one detect 

> MCL

Concentration)

Stage 2 2

(mean > MCL

Concentration)

Synthetic Organic Chemicals

Carbofuran

(40 μg/L) 0.000% 0.000% 0.000% 0.000%
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Contaminant 

(MCL Concentration)

Percent of Systems 

> MCL Concentration

Percent of Population Served by 

Systems > MCL Concentration

Stage 1 1

(one detect 

> MCL

Concentration)

Stage 2 2

(mean > MCL

Concentration)

Stage 1 1

(one detect 

> MCL

Concentration)

Stage 2 2

(mean > MCL

Concentration)

Chlordane

(2 μg/L) 0.013% 0.003% 0.000% 0.00004%

1,2-Dibromo-3-chloropropane 

(DBCP) 0.388% 0.112% 1.627% 0.013%

2,4-Dichlorophenoxyacetic acid 

(2,4-D) 0.003% 0.000% 0.007% 0.000%

Endothall

(100 μg/L) 0.021% 0.000% 0.063% 0.000%

Heptachlor

(0.4 μg/L) 0.006% 0.003% 0.003% 0.0002%

Heptachlor Epoxide

(0.2 μg/L) 0.018% 0.003% 0.010% 0.0002%

Hexachlorobenzene

(1 μg/L) 0.012% 0.009% 0.003% 0.001%

Hexachlorocyclopentadiene

(50 μg/L) 0.000% 0.000% 0.000% 0.000%

Oxamyl (Vydate)

(200 μg/L) 0.003% 0.000% 0.000% 0.000%

Toxaphene

(3 μg/L) 0.016% 0.010% 0.017% 0.014%

Volatile Organic Chemicals

Benzene

(5 μg/L) 0.125% 0.020% 0.215% 0.006%

Carbon Tetrachloride

(5 μg/L) 0.113% 0.010% 2.189% 0.001%

1,2-Dichloroethane

(5 μg/L) 0.071% 0.006% 0.193% 0.0001%

Dichloromethane (Methylene 

Chloride) 0.293% 0.026% 1.298% 0.005%

1,2-Dichloropropane

(5 μg/L) 0.020% 0.000% 0.155% 0.000%

Tetrachloroethylene (PCE)

(5 μg/L) 0.478% 0.046% 6.448% 0.277%

Toluene

(1,000 μg/L) 0.002% 0.002% 0.000% 0.000%

1,1,2-Trichloroethane

(5 μg/L) 0.014% 0.000% 0.056% 0.000%

Trichloroethylene (TCE)

(5 μg/L) 0.387% 0.050% 5.264% 0.181%

Vinyl Chloride

(2 μg/L) 0.081% 0.016% 0.213% 0.003%

Xylenes (Total) 

(10,000 μg/L) 0.000% 0.000% 0.000% 0.000%

1. The Stage 1 results represent the percent of systems with at least one sample analytical result greater than a 

contaminant’s MCL concentration.

2. The Stage 2 results represent the percent of systems with an estimated long-term mean concentration greater than 

a contaminant’s MCL concentration. The Stage 2 results presented here are based on long-term means generated by 

substituting zero for each non-detection record. For the Stage 2 results based on substituting the value of the full 

MRL or 1⁄2 MRL (instead of zero), please refer to Appendix B.
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8 Summary of Findings

The Six-Year Review-ICR Dataset contains more than 15 million analytical records from 

approximately 132,000 public water systems with data from 1998 to 2005 submitted by 45 states 

and 2 primacy agencies. This dataset is the largest and most comprehensive compliance 

monitoring dataset ever compiled and analyzed by EPA’s Drinking Water Program. Using the 

Six-Year Review-ICR Dataset, estimates of national occurrence in public drinking water systems 

were made for 65 regulated chemical contaminants and 4 regulated radionuclide contaminants 

with the Stage 1 analytical approach. Additional national occurrence estimates were made for 22

of the 65 regulated chemical contaminants with the Stage 2 analytical approach. 

Based on the Stage 1 analysis of national population served by systems with at least one 

sample analytical detection greater than each contaminant’s MCL concentration, the IOCs had 

occurrence as high as 7.310% (nitrate) and as low as 0.092% (barium).

The highest occurring SOC was di(2-ethylhexyl)phthalate with 6.397% of the population 

served by systems reporting at least one sample analytical detection greater its MCL

concentration. 1,2-Dibromo-3-chloropropane, atrazine, and ethylene dibromide also had high 

percentages (more than 1%) of population served by systems with detections greater than their 

respective MCL concentrations. On the low end of occurrence, seven SOCs –carbofuran, diquat, 

glyphosate, hexachlorocyclopentadiene, methoxychlor, picloram and silvex– were not detected 

above their respective MCL concentrations in any system nationally. 

The highest occurring VOC was tetrachloroethylene with 6.448% of the population 

served by systems reporting at least one sample analytical detection greater than its MCL

concentration. Trichloroethylene, 1,1-dichloroethylene, and carbon tetrachloride also had high 

percentages (more than 2%) of population served by systems with detections greater than their 

respective MCL concentrations. Six VOCs –1,2-dichlorobenzene, trans-1,2-dichloroethylene, 

ethylbenzene, monochlorobenzene, 1,2,4-trichlorobenzene and total xylenes– were not detected 

above their respective MCL concentrations in any systems nationally.

Based on the estimated percent of total population served by PWSs reporting at least one 

detection greater than each contaminant’s MCL concentration (in the case of beta particles, 

screening level), the occurrence findings of the radionuclides is as follows: uranium (11.884%); 

combined radium-226/-228 (9.620% pre-December 2003 and 9.201% post-December 2003); 

alpha particles (6.208%), and; beta particles (1.228%).

Eleven SOCs and eleven VOCs were additionally assessed using the Stage 2 analytical 

approach. Based on the population served by systems nationally with an estimated long-term 

mean contaminant concentration greater than the respective MCL concentration, the SOCs had 

occurrence as high as 0.014% (toxaphene) and as low as 0.000% (carbofuran, 2,4-

dichlorophenoxyacetic acid, endothall, hexachlorocyclopentadiene, and oxamyl). The two 

highest occurring VOCs were tetrachloroethylene with 0.277% of the population served by 

systems with a long-term mean greater than its MCL concentration, and trichloroethylene with 

0.181% of the population served by systems with a long-term mean greater than its MCL

concentration. For three of the VOCs evaluated using the Stage 2 analysis –1,2-dichloropropane, 
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1,1,2-trichloroethane, and total xylenes– no public water system nationally had an estimated 

long-term mean greater than each contaminant’s respective MCL concentration.
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9 References

Cadmus (The Cadmus Group, Inc.). 2008. The Data Management and Quality 

Assurance/Quality Control Process Used to Edit the State Compliance Monitoring Datasets 

Submitted for the Six-Year Review. Submitted to EPA on April 11, 2008.

Helsel, D.R., and R.M. Hirsch. 1991. “Statistical Methods in Water Resources,” Chapter A3, 

Book 4 of Techniques of Water-Resources Investigations of the United States Geologic Survey.

United States Environmental Protection Agency (USEPA). 2002. Analysis of National 

Occurrence of the 1998 Contaminant Candidate List (CCL) Regulatory Determination Priority 

Contaminants in Public Water Systems. EPA Report 815-D-01-002. May 2002.

USEPA. 2003a. National Primary Drinking Water Regulations; Announcement of Completion 

of EPA's Review of Existing Drinking Water Standards. Federal Register: July 18, 2003, 

Volume 68, Number 138, Page 42907-42929

USEPA. 2003b. Occurrence Estimation Methodology and Occurrence Findings for Six-Year 

Review of National Primary Drinking Water Regulations. EPA Report 815-R-03-006, Office of 

Water.

USEPA. 2003c. Drinking Water Baseline Handbook, Fourth Edition (Draft). September 4, 2003.

USEPA. 2006. Information Collection Request for Contaminant Occurrence Data in Support of 

EPA's Second Six-Year Review of National Primary Drinking Water Regulations. ICR no.

2231.01. OMB Control No. 2040-0275.

USEPA. 2008a. The Analysis of Occurrence Data from the Unregulated Contaminant 

Monitoring (UCM) Program and National Inorganics and Radionuclides Survey (NIRS) in 

Support of Regulatory Determinations for the Second Drinking Water Contaminant Candidate 

List. EPA Report 815-R-08-014. June 2008.

USEPA. 2008b. The Analysis of Occurrence Data from the First Unregulated Contaminant 

Monitoring Regulation (UCMR 1) in Support of Regulatory Determinations for the Second 

Drinking Water Contaminant Candidate List. EPA Report 815-R-08-013. June 2008.

USEPA. 2009a. Contaminant Occurrence Support Document for Category 1 Contaminants for 

the Second Six-Year Review of National Primary Drinking Water Regulations. EPA Report 815-

B-09-010. October 2009.

USEPA. 2009b. Contaminant Occurrence Support Document for Category 2 Contaminants for 

the Second Six-Year Review of National Primary Drinking Water Regulations. EPA Report 815-

B-09-011. October 2009.
APPENDICES

The Analysis of Regulated Contaminant Occurrence Data from Public 

Water Systems in Support of the Second Six-Year Review of National 

Primary Drinking Water Regulations

Appendix A. Stage 1 Analysis Occurrence Measures for All 

Regulated Contaminants

Appendix B. Stage 2 Analysis Occurrence Measures for Select 

Regulated Contaminants 
Appendix A. Stage 1 Analysis Occurrence Measures 

for All Regulated Contaminants

Table A1. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A1a. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A1b. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A1c. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A1d. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A2. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A2a. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A2b. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A2c. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A2d. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A3. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A3a. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A3b. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A3c. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A3d. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A4. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A4a. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A4b. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A4c. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A4d. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)
Table A4e. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A4f. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A5. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A5a. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A5b. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A5c. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations) 

Table A5d. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A6. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A6a. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A6b. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A6c. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A6d. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A7. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A7a. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A7b. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A7c. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A7d. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A8. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A8a. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A8b. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A8c. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A8d. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)
Table A8e. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A8f. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A9. Benzo(a)pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A9a. Benzo(a)pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A9b. Benzo(a)pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A9c. Benzo(a)pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A9d. Benzo(a)pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A10. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A10a. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A10b. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A10c. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A10d. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A11. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A11a. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A11b. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A11c. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A11d. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A12. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A12a. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A12b. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A12c. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A12d. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)
Table A13. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A13a. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A13b. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A13c. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A13d. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A13e. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A13f. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A14. Carbon Tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A14a. Carbon Tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A14b. Carbon Tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A14c. Carbon Tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A14d. Carbon Tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A14e. Carbon Tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A14f. Carbon Tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A15. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A15a. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A15b. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A15c. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A15d. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A16. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A16a. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A16b. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A16c. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)
Table A16d. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A17. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A17a. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A17b. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A17c. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A17d. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A18. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A18a. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A18b. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A18c. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A18d. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A19. Di(2-ethylhexyl)adipate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A19a. Di(2-ethylhexyl)adipate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A19b. Di(2-ethylhexyl)adipate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table 19c. Di(2-ethylhexyl)adipate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A19d. Di(2-ethylhexyl)adipate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A20. Di(2-ethylhexyl)phthalate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A20a. Di(2-ethylhexyl)phthalate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A20b. Di(2-ethylhexyl)phthalate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A20c. Di(2-ethylhexyl)phthalate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A20d. Di(2-ethylhexyl)phthalate – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A21. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses

(Single detections > threshold of interest are not necessarily MCL violations)
Table A21a. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A21b. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A21c. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A21d. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A22. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A22a. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A22b. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A22c. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A22d. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A23. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A23a. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A23b. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A23c. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A23d. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A24. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A24a. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A24b. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A24c. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A24d. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A24e. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A24f. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A25. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)
Table A25a. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A25b. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A25c. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A25d. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A26. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A26a. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A26b. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A26c. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A26d. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A27. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A27a. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A27b. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A27c. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A27d. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A28. Dichloromethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A28a. Dichloromethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A28b. Dichloromethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A28c. Dichloromethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A28d. Dichloromethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A28e. Dichloromethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A28f. Dichloromethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A29. 2,4-Dichlorophenoxyacetic Acid – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)
Table A29a. 2,4-Dichlorophenoxyacetic Acid – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A29b. 2,4-Dichlorophenoxyacetic Acid – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A29c. 2,4-Dichlorophenoxyacetic Acid – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A29d. 2,4-Dichlorophenoxyacetic Acid – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A29e. 2,4-Dichlorophenoxyacetic Acid – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A30. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A30a. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A30b. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A30c. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A30d. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A30e. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A30f. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A31. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A31a. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A31b. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A31c. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A31d. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A32. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A32a. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A32b. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A32c. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A32d. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)
Table A33. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A33a. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A33b. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A33c. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A33d. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A34. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A34a. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A34b. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A34c. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A34d. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A35. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A35a. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A35b. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A35c. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A35d. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A36. Ethylene Dibromide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A36a. Ethylene Dibromide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A36b. Ethylene Dibromide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A36c. Ethylene Dibromide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A36d. Ethylene Dibromide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A37. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A37a. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)
Table A37b. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A37c. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A37d. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A38. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A38a. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A38b. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A38c. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A38d. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A39. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A39a. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A39b. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A39c. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A39d. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A39e. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A40. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A40a. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A40b. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A40c. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A40d. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A41. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A41a. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A41b. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)
Table A41c. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A41d. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A41e. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A42. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A42a. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A42b. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A42c. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A42d. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A42e. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A43. Lindane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A43a. Lindane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A43b. Lindane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A43c. Lindane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A43d. Lindane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A44. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A44a. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A44b. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A44c. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A44d. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)
Table A45. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A45a. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A45b. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A45c. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A45d. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A46. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A46a. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A46b. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A46c. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A46d. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A47. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A47a. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A47b. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A47c. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A47d. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A48. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A48a. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A48b. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A48c. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A48d. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A49. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A49a. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)
Table A49b. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A49c. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A49d. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A49e. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A50. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A50a. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A50b. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A50c. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A50d. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A51. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A51a. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A51b. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A51c. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A51d. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A52. Polychlorinated Biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A52a. Polychlorinated Biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A52b. Polychlorinated Biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A52c. Polychlorinated Biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A52d. Polychlorinated Biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses 

(Single detections > threshold of interest are not necessarily MCL violations)

Table A53 (Original Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53a (Original Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53b (Original Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)
Table A53c (Original Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53d (Original Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53 (Revised Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53a (Revised Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53b (Revised Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53c (Revised Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A53d (Revised Rule). Combined Radium – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A54. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A54a. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A54b. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A54c. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A54d. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A55. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A55a. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A55b. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A55c. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A55d. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A56. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A56a. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A56b. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A56c. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A56d. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)
Table A57. 2,3,7,8-TCDD (Dioxin) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A57a. 2,3,7,8-TCDD (Dioxin) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A57b. 2,3,7,8-TCDD (Dioxin) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A57c. 2,3,7,8-TCDD (Dioxin) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A57d. 2,3,7,8-TCDD (Dioxin) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A58. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A58a. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A58b. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A58c. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A58d. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A58e. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A58f. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A59. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A59a. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold

of interest are not necessarily MCL violations)

Table A59b. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A59c. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A59d. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A60. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A60a. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A60b. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A60c. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A60d. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)

Table A60e. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of 

interest are not necessarily MCL violations)
Table A61. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A61a. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A61b. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A61c. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A61d. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A61e. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A62. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A62a. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A62b. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A62c. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A62d. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A63. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A63a. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A63b. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A63c. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A63d. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A64. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A64a. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A64b. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A64c. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A64d. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A64e. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)
Table A65. 2,4,5-Trichlorophenoxypropionic acid (Silvex) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A65a. 2,4,5-Trichlorophenoxypropionic acid (Silvex) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A65b. 2,4,5-Trichlorophenoxypropionic acid (Silvex) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A65c. 2,4,5-Trichlorophenoxypropionic acid (Silvex) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A65d. 2,4,5-Trichlorophenoxypropionic acid (Silvex) – Summary of the Stage 1 (Peak) 

Analyses (Single detections > threshold of interest are not necessarily MCL 

violations)

Table A66. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A66a. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A66b. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A66c. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A66d. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A66e. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A66f. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single 

detections > threshold of interest are not necessarily MCL violations)

Table A67. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A67a. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A67b. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A67c. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A67d. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold 

of interest are not necessarily MCL violations)

Table A68. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A68a. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A68b. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)
Table A68c. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A68d. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A68e. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections 

> threshold of interest are not necessarily MCL violations)

Table A69. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A69a. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A69b. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A69c. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A69d. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)

Table A69e. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > 

threshold of interest are not necessarily MCL violations)
Appendix B. Stage 2 Analysis Occurrence Measures

for Select Regulated Contaminants

Table B1. Benzene – Summary of the Stage 2 Analyses

Table B2. Carbofuran – Summary of the Stage 2 Analyses

Table B3. Carbon Tetrachloride – Summary of the Stage 2 Analyses

Table B4. Chlordane – Summary of the Stage 2 Analyses

Table B5. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 2 Analyses

Table B6. 1,2-Dichloroethane – Summary of the Stage 2 Analyses

Table B7. Dichloromethane – Summary of the Stage 2 Analyses

Table B8. 2,4-Dichlorophenoxyacetic Acid – Summary of the Stage 2 Analyses

Table B9. 1,2-Dichloropropane – Summary of the Stage 2 Analyses

Table B10. Endothall – Summary of the Stage 2 Analyses

Table B11. Heptachlor – Summary of the Stage 2 Analyses

Table B12. Heptachlor Epoxide – Summary of the Stage 2 Analyses

Table B13. Hexachlorobenzene – Summary of the Stage 2 Analyses

Table B14. Hexachlorocyclopentadiene – Summary of the Stage 2 Analyses

Table B15. Oxamyl (Vydate) – Summary of the Stage 2 Analyses

Table B16. Tetrachloroethylene (PCE) – Summary of the Stage 2 Analyses

Table B17. Toluene – Summary of the Stage 2 Analyses

Table B18. Toxaphene – Summary of the Stage 2 Analyses

Table B19. 1,1,2-Trichloroethane – Summary of the Stage 2 Analyses

Table B20. Trichloroethylene (TCE) – Summary of the Stage 2 Analyses

Table B21. Vinyl Chloride – Summary of the Stage 2 Analyses

Table B22. Xylenes (Total) – Summary of the Stage 2 Analyses
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A1. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.002 mg/L 44,863 64 0.143% 85,514,854 617,666 0.722%	
 44,863 223 0.497% 85,514,854 2,282,255 2.669%

> 0.002 mg/L 3,996 18 0.450% 144,338,525 1,973,654 1.367%

	
 3,996 51 1.276% 144,338,525 10,552,870 7.311%

> 0.002 mg/L 48,859 82 0.168% 229,853,379 2,591,320 1.127%

	
 48,859 274 0.561% 229,853,379 12,835,125 5.584%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A1a. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 866 613 253 1.963% 2.121% 1.581% 0.0002 0.0002 0.0002 0.0003 0.0003 0.0002 0.00051 0.00051 0.00027 0.0071 0.0071 0.00027AL 2,683 1,829 854 1.416% 1.093% 2.108% 0.00003 0.00006 0.00003 0.0005 0.00047 0.00059 0.00147 0.0011 0.0015 0.002 0.002 0.0019AR 2,186 1,529 657 0.091% 0.131% 0.000% 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005AZ 6,219 4,855 1,364 1.769% 1.833% 1.540% 0.0001 0.0001 0.00012 0.0003 0.00039 0.0002 0.0011 0.0011 0.001 0.0031 0.0031 0.0011CA 34,622 20,422 14,200 1.765% 2.155% 1.204% 2.1E-05 2.1E-05 2.2E-05 0.00011 0.00012 0.0001 0.0012 0.0012 0.0012 0.01 0.01 0.009CO 4,378 2,321 2,057 1.256% 0.991% 1.556% 0.00005 0.0001 0.00005 0.0002 0.0002 0.00021 0.00097 0.00097 0.00051 0.002 0.0018 0.002CT 2,589 1,866 723 1.159% 1.447% 0.415% 0.00009 0.00009 0.0002 0.0003 0.00029 0.0003 0.002 0.002 0.002 0.002 0.002 0.002DE 762 709 53 2.493% 2.539% 1.887% 0.0001 0.0001 0.0001 0.0005 0.0005 0.0001 0.002 0.002 0.0001 0.01 0.01 0.0001FL 2,149 2,080 69 5.398% 5.481% 2.899% 0.0001 0.0001 0.0001 0.0002 0.0002 0.0004 0.0007 0.0007 0.0007 0.002 0.002 0.0007GA 3,646 3,005 641 0.082% 0.033% 0.312% 0.00026 0.0016 0.00026 0.0016 0.0016 0.00263 0.005 0.0016 0.005 0.005 0.0016 0.005HI 1,178 1,116 62 0.170% 0.179% 0.000% 0.0006 0.0006 0.00065 0.00065 0.0007 0.0007 0.0007 0.0007IA 1,491 1,228 263 0.671% 0.814% 0.000% 0.0002 0.0002 0.00037 0.00037 0.00081 0.00081 0.001 0.001ID 2,664 2,386 278 1.051% 1.006% 1.439% 0.0001 0.0001 0.0002 0.00042 0.00047 0.0003 0.0022 0.0022 0.0009 0.06 0.06 0.0009IL 3,420 3,017 403 0.526% 0.464% 0.993% 6.5E-05 6.5E-05 0.00011 0.0002 0.00022 0.00017 0.00096 0.00096 0.0003 0.002 0.002 0.0003IN 4,699 4,216 483 1.000% 0.783% 2.899% 0.0001 0.0001 0.0001 0.00023 0.0002 0.00055 0.0013 0.0015 0.0009 0.002 0.002 0.001KY 1,758 532 1,226 4.039% 2.820% 4.568% 0.0001 0.0002 0.0001 0.0003 0.0003 0.0003 0.0007 0.0085 0.0007 0.0086 0.0086 0.003MA 2,982 2,022 960 1.979% 2.324% 1.250% 0.00004 0.00004 0.0002 0.00027 0.00026 0.0005 0.001 0.001 0.0005 0.01 0.01 0.002MD 5,096 3,986 1,110 0.608% 0.477% 1.081% 0.0001 0.0002 0.0001 0.0005 0.0005 0.00055 0.0019 0.002 0.0016 0.006 0.006 0.0032ME 2,702 2,302 400 1.925% 2.215% 0.250% 0.00005 0.00005 0.0001 0.0001 0.0001 0.0001 0.00013 0.00013 0.0001 0.0003 0.0003 0.0001MI 5,591 5,436 155 4.525% 4.507% 5.161% 0.00003 0.00003 0.00003 0.00004 0.00004 0.00004 0.00013 0.00014 0.0001 0.00506 0.00506 0.0001MN 3,207 3,159 48 0.904% 0.823% 6.250% 0.00003 0.00003 0.00003 0.00006 0.00006 0.00005 0.00027 0.00027 0.00012 0.00037 0.00037 0.00012MO 5,704 4,923 781 0.666% 0.711% 0.384% 0.00004 0.00004 0.00016 0.00028 0.00028 0.00019 0.00087 0.00087 0.00032 0.00114 0.00114 0.00032MT 2,751 2,472 279 0.327% 0.324% 0.358% 0.0002 0.0002 0.0002 0.0003 0.0003 0.0002 0.0028 0.0028 0.0002 0.0028 0.0028 0.0002NC 9,222 7,786 1,436 1.247% 1.259% 1.184% 0.00006 0.0001 0.00006 0.0003 0.0003 0.0003 0.0007 0.0007 0.0006 0.03 0.03 0.0007ND 348 304 44 0.000% 0.000% 0.000%NE 1,937 1,849 88 0.000% 0.000% 0.000%NH 2,928 2,764 164 0.376% 0.398% 0.000% 0.0001 0.0001 0.0003 0.0003 0.0026 0.0026 0.0078 0.0078NJ 6,722 6,004 718 5.356% 5.763% 1.950% 0.00004 0.00004 0.00004 0.0004 0.00042 0.00025 0.00157 0.0016 0.0005 0.03 0.03 0.001NM 3,508 3,182 326 1.226% 1.288% 0.613% 0.0002 0.0002 0.0005 0.0003 0.0003 0.00125 0.0014 0.0014 0.002 0.0026 0.0026 0.002NV 1,836 1,305 531 1.634% 1.686% 1.507% 0.0001 0.0001 0.0002 0.0004 0.00039 0.00042 0.00091 0.001 0.00081 0.0028 0.0028 0.00081NY 3,398 2,546 852 0.971% 0.943% 1.056% 0.0002 0.0002 0.0002 0.0002 0.0002 0.00028 0.002 0.002 0.0021 0.004 0.004 0.0021OH 4,553 3,927 626 1.340% 1.477% 0.479% 0.00012 0.00012 0.00021 0.00035 0.00036 0.0003 0.001 0.00105 0.00065 0.02 0.02 0.00065OK 420 346 74 0.476% 0.578% 0.000% 0.00005 0.00005 0.00014 0.00014 0.00022 0.00022 0.00022 0.00022OR 1,320 957 363 0.455% 0.627% 0.000% 0.0002 0.0002 0.00095 0.00095 0.0013 0.0013 0.0013 0.0013RI 904 674 230 0.221% 0.297% 0.000% 0.0025 0.0025 0.00625 0.00625 0.01 0.01 0.01 0.01SC 3,403 2,940 463 2.116% 1.259% 7.559% 0.0002 0.0002 0.00032 0.00045 0.0003 0.00049 0.002 0.0018 0.0039 0.02 0.0045 0.02SD 388 359 29 1.289% 1.114% 3.448% 0.0002 0.0002 0.0011 0.0008 0.0005 0.0011 0.0013 0.0013 0.0011 0.0013 0.0013 0.0011TN 1,631 482 1,149 1.165% 0.415% 1.480% 0.00009 0.0002 0.00009 0.0003 0.0007 0.0003 0.0012 0.0012 0.0011 0.0016 0.0012 0.0016TX 14,712 12,141 2,571 0.387% 0.387% 0.389% 0.0002 0.0002 0.00021 0.0004 0.0005 0.0003 0.00125 0.0013 0.00053 0.0019 0.0019 0.00053UT 6,931 5,432 1,499 5.194% 5.468% 4.203% 0.0001 0.0001 0.0001 0.0002 0.0002 0.0002 0.0004 0.0004 0.0004 0.001 0.001 0.0006VA 2,804 2,195 609 0.713% 0.774% 0.493% 0.0002 0.0002 0.0002 0.0002 0.0002 0.0002 0.00075 0.001 0.0005 0.0026 0.0026 0.0005VT 2,059 1,738 321 0.826% 0.921% 0.312% 0.00003 0.00003 0.0003 0.0002 0.0002 0.0003 0.002 0.002 0.0003 0.02 0.02 0.0003WI 7,023 6,851 172 4.841% 4.904% 2.326% 2.5E-05 2.5E-05 0.0001 0.00015 0.00015 0.00045 0.00042 0.00041 0.0028 0.0077 0.0077 0.0028WV 1,116 423 693 3.495% 4.965% 2.597% 9.3E-05 9.3E-05 9.3E-05 0.001 0.001 0.00057 0.002 0.001 0.0027 0.1 0.002 0.1WY 1,123 875 248 0.890% 1.029% 0.403% 0.0001 0.0001 0.003 0.00055 0.0005 0.003 0.00225 0.0015 0.003 0.003 0.0015 0.003Total 181,629 141,104 40,525 1.789% 1.894% 1.426% 2.1E-05 2.1E-05 2.2E-05 0.0002 0.0002 0.0002 0.001 0.001 0.001 0.1 0.06 0.1

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A1b. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 490 389 101 546,448 210,227 336,221 3.061% 3.085% 2.970% 43.258% 1.748% 69.213%AL 352 279 73 4,701,100 1,463,066 3,238,034 7.955% 5.735% 16.438% 28.081% 10.073% 36.218%AR 453 381 72 2,452,800 909,774 1,543,026 0.221% 0.262% 0.000% 0.020% 0.054% 0.000%AZ 1,049 1,001 48 6,161,306 2,790,715 3,370,591 5.338% 4.795% 16.667% 51.813% 10.985% 85.617%CA 3,772 3,252 520 36,340,528 13,511,104 22,829,424 6.098% 5.566% 9.423% 33.929% 32.197% 34.954%CO 838 617 221 4,998,506 533,275 4,465,231 4.415% 2.593% 9.502% 17.246% 1.553% 19.121%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 2.393% 2.210% 7.692% 3.019% 1.056% 3.341%DE 281 278 3 679,823 398,423 281,400 2.135% 1.799% 33.333% 20.553% 8.648% 37.409%FL 1,335 1,309 26 17,251,183 15,005,141 2,246,042 4.270% 4.202% 7.692% 26.294% 28.131% 14.021%GA 1,734 1,618 116 7,466,977 1,574,196 5,892,781 0.173% 0.062% 1.724% 1.371% 0.011% 1.735%HI 107 95 12 1,303,767 1,249,139 54,628 0.935% 1.053% 0.000% 0.031% 0.032% 0.000%IA 967 934 33 2,500,395 1,391,769 1,108,626 1.034% 1.071% 0.000% 1.443% 2.593% 0.000%ID 896 848 48 1,050,473 806,038 244,435 2.567% 2.594% 2.083% 26.491% 11.449% 76.094%IL 1,489 1,386 103 9,168,041 2,967,969 6,200,072 1.075% 0.938% 2.913% 4.084% 6.653% 2.854%IN 1,622 1,573 49 4,980,031 2,619,576 2,360,455 2.528% 1.971% 20.408% 29.845% 4.558% 57.907%KY 242 93 149 4,602,489 375,460 4,227,029 18.182% 10.753% 22.819% 43.234% 7.753% 46.386%MA 676 558 118 8,525,575 1,718,151 6,807,424 5.030% 5.197% 4.237% 43.332% 3.528% 53.379%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 2.505% 1.649% 14.706% 40.382% 25.692% 44.146%ME 806 752 54 727,707 292,103 435,604 4.839% 5.053% 1.852% 5.906% 13.898% 0.546%MI 2,850 2,801 49 6,539,864 1,815,364 4,724,500 8.316% 8.283% 10.204% 59.692% 22.622% 73.936%MN 1,438 1,411 27 3,894,967 2,661,430 1,233,537 1.878% 1.772% 7.407% 3.698% 4.478% 2.015%MO 1,421 1,344 77 3,006,743 1,692,282 1,314,461 2.111% 2.083% 2.597% 1.817% 1.400% 2.354%MT 845 786 59 757,505 365,106 392,399 0.828% 0.763% 1.695% 0.445% 0.900% 0.022%NC 2,285 2,146 139 6,973,678 1,708,512 5,265,166 4.245% 3.868% 10.072% 13.455% 6.417% 15.739%ND 217 190 27 563,069 257,844 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 731 720 11 1,449,290 672,810 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,216 1,175 41 942,517 392,718 549,799 0.658% 0.681% 0.000% 2.179% 5.230% 0.000%NJ 1,372 1,335 37 7,762,526 2,726,580 5,035,946 12.026% 11.685% 24.324% 21.470% 34.076% 14.645%NM 720 681 39 1,667,049 1,400,501 266,548 5.000% 4.993% 5.128% 8.281% 9.233% 3.282%NV 324 304 20 970,526 280,727 689,799 7.407% 5.921% 30.000% 46.780% 17.939% 58.517%NY 1,571 1,332 239 11,195,033 1,218,149 9,976,884 2.101% 1.802% 3.766% 0.855% 0.974% 0.841%OH 1,915 1,790 125 10,216,143 3,121,206 7,094,937 2.663% 2.682% 2.400% 0.952% 1.473% 0.723%OK 202 175 27 749,266 276,712 472,554 0.990% 1.143% 0.000% 0.219% 0.594% 0.000%OR 733 611 122 2,777,164 487,418 2,289,746 0.819% 0.982% 0.000% 0.124% 0.706% 0.000%RI 143 134 9 913,584 173,606 739,978 1.399% 1.493% 0.000% 3.139% 16.521% 0.000%SC 822 757 65 3,462,560 804,033 2,658,527 5.231% 3.435% 26.154% 36.478% 3.526% 46.444%SD 235 224 11 328,972 237,011 91,961 2.128% 1.786% 9.091% 22.993% 4.919% 69.576%TN 350 161 189 5,683,572 1,460,816 4,222,756 4.286% 1.242% 6.878% 12.423% 0.040% 16.707%TX 4,888 4,547 341 25,060,220 9,275,719 15,784,501 1.002% 0.968% 1.466% 5.944% 14.742% 0.773%UT 507 457 50 2,543,652 1,686,017 857,635 18.343% 16.849% 32.000% 59.137% 49.220% 78.633%VA 1,582 1,414 168 4,803,450 634,384 4,169,066 0.822% 0.778% 1.190% 0.202% 0.889% 0.097%VT 598 556 42 490,389 226,621 263,768 2.508% 2.518% 2.381% 1.151% 1.210% 1.099%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 13.165% 13.145% 15.000% 16.875% 24.966% 5.623%WV 450 290 160 1,415,227 234,687 1,180,540 7.778% 7.241% 8.750% 4.848% 4.737% 4.870%WY 304 255 49 446,184 129,168 317,016 2.961% 3.137% 2.041% 0.858% 1.366% 0.651%Total 48,859 44,863 3,996 229,853,379 85,514,854 144,338,525 3.964% 3.669% 7.282% 20.052% 17.131% 21.783%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A1c. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.204% 0.257% 0.000% 200 200 0 0.037% 0.095% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 2 2 0 0.191% 0.200% 0.000% 277 277 0 0.004% 0.010% 0.000%CA 16 10 6 0.424% 0.308% 1.154% 1,873,292 502,592 1,370,700 5.155% 3.720% 6.004%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 1 1 0 0.356% 0.360% 0.000% 6,150 6,150 0 0.905% 1.544% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.058% 0.000% 0.862% 2,671 0 2,671 0.036% 0.000% 0.045%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 3 3 0 0.335% 0.354% 0.000% 2,163 2,163 0 0.206% 0.268% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 3 2 1 1.240% 2.151% 0.671% 99,748 4,877 94,871 2.167% 1.299% 2.244%MA 2 2 0 0.296% 0.358% 0.000% 745 745 0 0.009% 0.043% 0.000%MD 2 1 1 0.193% 0.103% 1.471% 4,058 58 4,000 0.081% 0.006% 0.100%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 2 2 0 0.070% 0.071% 0.000% 109 109 0 0.002% 0.006% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 150 150 0 0.020% 0.041% 0.000%NC 2 2 0 0.088% 0.093% 0.000% 65 65 0 0.001% 0.004% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 2 2 0 0.164% 0.170% 0.000% 113 113 0 0.012% 0.029% 0.000%NJ 16 16 0 1.166% 1.199% 0.000% 27,879 27,879 0 0.359% 1.022% 0.000%NM 1 1 0 0.139% 0.147% 0.000% 23,540 23,540 0 1.412% 1.681% 0.000%NV 1 1 0 0.309% 0.329% 0.000% 30 30 0 0.003% 0.011% 0.000%NY 2 1 1 0.127% 0.075% 0.418% 18,643 3,000 15,643 0.167% 0.246% 0.157%OH 2 2 0 0.104% 0.112% 0.000% 960 960 0 0.009% 0.031% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 2 2 0 1.399% 1.493% 0.000% 28,681 28,681 0 3.139% 16.521% 0.000%SC 6 3 3 0.730% 0.396% 4.615% 426,360 1,699 424,661 12.313% 0.211% 15.974%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.071% 0.000% 98 98 0 0.002% 0.015% 0.000%VT 1 1 0 0.167% 0.180% 0.000% 40 40 0 0.008% 0.018% 0.000%WI 8 7 1 0.439% 0.388% 5.000% 35,580 14,240 21,340 0.880% 0.605% 1.261%WV 3 0 3 0.667% 0.000% 1.875% 37,703 0 37,703 2.664% 0.000% 3.194%WY 1 0 1 0.329% 0.000% 2.041% 2,065 0 2,065 0.463% 0.000% 0.651%Total 82 64 18 0.168% 0.143% 0.450% 2,591,320 617,666 1,973,654 1.127% 0.722% 1.367%

Percent of Population Served 

with At Least One Detection 

> 0.002 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.002 mg/L

Percent of Systems 

with At Least One Detection 

> 0.002 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.002 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A1d. Alachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.204% 0.257% 0.000% 200 200 0 0.037% 0.095% 0.000%AL 6 2 4 1.705% 0.717% 5.479% 958,009 3,342 954,667 20.378% 0.228% 29.483%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 13 11 2 1.239% 1.099% 4.167% 715,990 90,765 625,225 11.621% 3.252% 18.549%CA 55 39 16 1.458% 1.199% 3.077% 7,342,316 1,126,527 6,215,789 20.204% 8.338% 27.227%CO 4 2 2 0.477% 0.324% 0.905% 147,212 445 146,767 2.945% 0.083% 3.287%CT 7 6 1 0.598% 0.531% 2.564% 37,823 1,756 36,067 1.393% 0.459% 1.545%DE 1 1 0 0.356% 0.360% 0.000% 6,150 6,150 0 0.905% 1.544% 0.000%FL 8 8 0 0.599% 0.611% 0.000% 515,436 515,436 0 2.988% 3.435% 0.000%GA 2 1 1 0.115% 0.062% 0.862% 2,846 175 2,671 0.038% 0.011% 0.045%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 1 1 0 0.103% 0.107% 0.000% 510 510 0 0.020% 0.037% 0.000%ID 3 3 0 0.335% 0.354% 0.000% 2,163 2,163 0 0.206% 0.268% 0.000%IL 1 1 0 0.067% 0.072% 0.000% 684 684 0 0.007% 0.023% 0.000%IN 8 7 1 0.493% 0.445% 2.041% 49,172 43,184 5,988 0.987% 1.649% 0.254%KY 3 2 1 1.240% 2.151% 0.671% 99,748 4,877 94,871 2.167% 1.299% 2.244%MA 6 5 1 0.888% 0.896% 0.847% 11,042 8,156 2,886 0.130% 0.475% 0.042%MD 5 2 3 0.482% 0.206% 4.412% 1,725,538 238 1,725,300 34.356% 0.023% 43.153%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 2 2 0 0.070% 0.071% 0.000% 109 109 0 0.002% 0.006% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.070% 0.074% 0.000% 235 235 0 0.008% 0.014% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 150 150 0 0.020% 0.041% 0.000%NC 5 5 0 0.219% 0.233% 0.000% 2,206 2,206 0 0.032% 0.129% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 4 4 0 0.329% 0.340% 0.000% 19,166 19,166 0 2.033% 4.880% 0.000%NJ 41 40 1 2.988% 2.996% 2.703% 274,161 124,161 150,000 3.532% 4.554% 2.979%NM 7 6 1 0.972% 0.881% 2.564% 36,726 28,102 8,624 2.203% 2.007% 3.235%NV 3 3 0 0.926% 0.987% 0.000% 3,163 3,163 0 0.326% 1.127% 0.000%NY 5 4 1 0.318% 0.300% 0.418% 19,087 3,444 15,643 0.170% 0.283% 0.157%OH 6 6 0 0.313% 0.335% 0.000% 7,974 7,974 0 0.078% 0.255% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 3 3 0 0.409% 0.491% 0.000% 3,306 3,306 0 0.119% 0.678% 0.000%RI 2 2 0 1.399% 1.493% 0.000% 28,681 28,681 0 3.139% 16.521% 0.000%SC 10 5 5 1.217% 0.661% 7.692% 428,676 2,025 426,651 12.380% 0.252% 16.048%SD 2 1 1 0.851% 0.446% 9.091% 64,027 44 63,983 19.463% 0.019% 69.576%TN 3 1 2 0.857% 0.621% 1.058% 9,677 33 9,644 0.170% 0.002% 0.228%TX 10 10 0 0.205% 0.220% 0.000% 13,335 13,335 0 0.053% 0.144% 0.000%UT 1 1 0 0.197% 0.219% 0.000% 15,800 15,800 0 0.621% 0.937% 0.000%VA 2 2 0 0.126% 0.141% 0.000% 423 423 0 0.009% 0.067% 0.000%VT 2 2 0 0.334% 0.360% 0.000% 190 190 0 0.039% 0.084% 0.000%WI 14 13 1 0.768% 0.721% 5.000% 242,886 221,546 21,340 6.005% 9.417% 1.261%WV 23 17 6 5.111% 5.862% 3.750% 47,732 3,043 44,689 3.373% 1.297% 3.785%WY 3 2 1 0.987% 0.784% 2.041% 2,576 511 2,065 0.577% 0.396% 0.651%Total 274 223 51 0.561% 0.497% 1.276% 12,835,125 2,282,255 10,552,870 5.584% 2.669% 7.311%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A2. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration or 

Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 15 pCi/L 16,467 832 5.053% 40,744,045 2,891,759 7.097%


	
 16,467 2,511 15.249% 40,744,045 8,323,500 20.429%

> 15 pCi/L 2,186 22 1.006% 80,426,355 4,631,051 5.758%


	
 2,186 85 3.888% 80,426,355 10,037,894 12.481%

> 15 pCi/L 18,653 854 4.578% 121,170,400 7,522,810 6.208%


	
 18,653 2,596 13.917% 121,170,400 18,361,394 15.153%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A2a. Alpha Particles– Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 776 598 178 45.361% 53.344% 18.539% 0.09 0.09 0.37 1.2 1.2 1.1 4.5 4.7 2 9.99 9.99 3AL 1,783 1,211 572 55.693% 61.354% 43.706% 0.005 0.005 0.1 0.9 1.1 0.5 3.5 4.1 2.01 42 42 9.64ARAZ 6,201 4,406 1,795 91.292% 94.507% 83.398% 0.1 0.1 0.1 2.9 3.1 2.1 7.2 7.8 4.9 25.3 25.3 14.3CACO 1,194 968 226 78.392% 82.335% 61.504% 0.01 0.01 0.01 4.1 4.8 2.1 25 26 12 154 154 47.4CT 2,014 1,818 196 39.275% 40.869% 24.490% 0.02 0.04 0.02 3.48 3.6 0.925 11.73 12 4.3 60.45 60.45 9.75DEFL 783 740 43 69.221% 70.135% 53.488% 0.03 0.03 0.9 2.1 2.2 1.3 6.6 6.7 3.4 40 40 4.2GAHIIA 44 44 0 95.455% 95.455% 3.2 3.2 18.9 18.9 32.1 32.1 48.8 48.8ID 873 804 69 83.620% 84.328% 75.362% 0.02 0.02 0.1 3.3 3.4 1.6 17.35 18.4 9.9 107.2 107.2 31.3ILIN 130 130 0 56.923% 56.923% 0.1 0.1 1.25 1.25 3.9 3.9 11.6 11.6KY 1,309 425 884 68.831% 88.941% 59.163% 8E-10 8E-10 0.02 0.6 0.8 0.5 2 2.6 1.6 19.9 12.3 19.9MAMD 2,012 1,641 371 59.394% 61.060% 52.022% 0.19 0.19 0.5 3 3 2 14 14 14 72 72 35ME 715 633 82 98.182% 98.262% 97.561% 0.01 0.01 0.01 1.14 1.385 0.325 12.14 13.14 1.92 348.33 348.33 133.53MI 3,026 2,921 105 37.938% 38.651% 18.095% 0.01 0.01 0.1 2.865 2.9 2.1 7.4 7.4 6 33.4 33.4 10MN 3,212 3,166 46 73.692% 74.574% 13.043% 0.27 0.27 0.4 6.46 6.5 1.1 17.9 17.9 5 84 84 5MO 515 492 23 83.107% 86.382% 13.043% 0.2 0.2 1 5.4 5.5 4.2 22.1 22.1 6.3 96.6 96.6 6.3MT 1,878 1,730 148 44.941% 46.532% 26.351% 0.2 0.2 0.67 2.9 3 1.6 8 8 8.9 17.1 17.1 14.1NC 10,941 10,266 675 38.726% 40.162% 16.889% 0.01 0.01 0.03 4.29 4.36 0.425 20.68 21.22 3.6 295.5 295.5 7.2ND 15 13 2 46.667% 38.462% 100.000% 0.19 0.19 0.8 1.5 1.5 3.7 6.6 4.4 6.6 6.6 4.4 6.6NE 503 486 17 72.167% 72.016% 76.471% 0.1 0.1 0.2 6.2 6.3 4.1 15.3 15.7 8.1 60 60 9.5NHNJ 2,589 2,125 464 69.641% 72.094% 58.405% 0.01 0.01 0.02 5.4 5.4 5.3 17 17 16 280 280 100NM 2,868 2,679 189 88.389% 88.503% 86.772% 0.1 0.1 0.1 4.6 4.8 1.55 23.7 24.9 6 155 155 16.2NV 357 321 36 59.104% 62.305% 30.556% 0.05 0.05 1.1 1.5 1.465 2 5 5 4.49 66.92 66.92 5.1NY 556 452 104 55.396% 56.195% 51.923% 0.01 0.01 0.04 1.69 2.04 0.825 5.84 6.44 3.4 36 36 5.52OH 2,626 2,014 612 12.643% 15.144% 4.412% 0.2 0.2 0.4 4.11 4.23 3.46 7.83 8.05 6.05 15.3 15.3 7.09OKOR 929 733 196 10.872% 11.460% 8.673% 0.01 0.01 0.17 1.34 1.425 1 5.4 5.4 5.85 39.1 39.1 8.1RI 509 450 59 75.442% 77.778% 57.627% 0.05 0.05 0.13 3.075 3.57 1.165 12.21 12.605 2.72 71.32 71.32 5.02SC 1,858 1,706 152 60.118% 62.134% 37.500% 1 1 1 3.4 3.5 1.6 12.9 12.9 10.5 101 101 30SD 457 417 40 80.525% 80.576% 80.000% 0.3 0.3 0.7 3.6 3.7 2.4 10.6 11 6.8 31 31 7.8TN 2,039 980 1,059 52.771% 63.571% 42.776% 0.01 0.01 0.03 1.1 1.25 1 2.3 2.7 1.7 17.8 17.8 6.9TX 12,449 10,942 1,507 49.161% 51.800% 29.993% 2 2 2 5.6 5.7 4.8 16.6 16.8 15.3 205.1 205.1 59.6UT 4,577 3,780 797 64.868% 68.122% 49.435% 1 1 1 3 3 4 8 8 8 70 70 17VA 708 574 134 82.768% 82.578% 83.582% 0.1 0.1 0.1 0.9 1.1 0.5 6.3 7.3 1.5 27 27 6VT 1,018 900 118 66.798% 69.000% 50.000% 0.03 0.1 0.03 2.515 2.71 1.39 14.65 15.45 3.87 56.1 56.1 7.62WIWV 800 463 337 74.375% 80.562% 65.875% 0.1 0.1 0.1 0.9 1.1 0.5 3.6 5.3 1.9 21 21 6.5WY 738 625 113 42.412% 42.560% 41.593% 0.1 0.1 0.59 3 3.4 1.8 12.1 12.3 5.9 39.9 39.9 25.5Total 73,002 61,653 11,349 57.274% 58.993% 47.934% 8E-10 8E-10 0.01 3.36 3.7 1.6 13 13.81 6.8 348.33 348.33 133.53

Median Detect 

Concentration (pCi/L)

Maximum Detect 

Concentration (pCi/L)

90th Percentile Detect 

Concentration (pCi/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (pCi/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A2b. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 264 193 71 479,135 165,352 313,783 39.394% 46.114% 21.127% 11.821% 27.168% 3.733%AL 321 251 70 4,687,044 1,453,506 3,233,538 87.539% 86.454% 91.429% 92.626% 92.678% 92.603%ARAZ 711 673 38 5,860,832 2,506,861 3,353,971 99.156% 99.108% 100.000% 99.986% 99.968% 100.000%CACO 397 301 96 3,880,820 312,339 3,568,481 73.804% 77.076% 63.542% 51.283% 91.187% 47.791%CT 471 438 33 2,392,156 230,267 2,161,889 71.762% 72.831% 57.576% 61.589% 79.964% 59.632%DEFL 207 191 16 7,941,994 5,906,110 2,035,884 84.541% 85.340% 75.000% 84.347% 87.451% 75.341%GAHIIA 20 20 0 29,225 29,225 0 95.000% 95.000% 97.047% 97.047%ID 440 411 29 841,950 617,866 224,084 86.591% 87.348% 75.862% 97.645% 97.977% 96.729%ILIN 33 33 0 98,260 98,260 0 78.788% 78.788% 76.183% 76.183%KY 207 67 140 4,588,246 366,366 4,221,880 96.618% 98.507% 95.714% 90.946% 99.990% 90.161%MAMD 516 459 57 4,891,562 898,778 3,992,784 75.388% 75.163% 77.193% 96.762% 92.584% 97.702%ME 370 323 47 612,751 212,054 400,697 99.459% 99.381% 100.000% 99.935% 99.811% 100.000%MI 1,203 1,146 57 6,713,368 1,723,511 4,989,857 49.377% 50.436% 28.070% 69.591% 56.999% 73.940%MN 922 899 23 4,068,067 2,822,206 1,245,861 81.236% 82.870% 17.391% 74.689% 89.221% 41.770%MO 287 264 23 644,443 401,616 242,827 75.610% 81.061% 13.043% 60.727% 81.931% 25.658%MT 631 574 57 708,638 316,159 392,479 62.124% 63.240% 50.877% 53.262% 73.404% 37.037%NC 1,826 1,694 132 6,843,768 1,583,217 5,260,551 72.070% 73.908% 48.485% 58.694% 71.066% 54.970%ND 7 5 2 17,046 12,881 4,165 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%NE 96 95 1 204,396 179,337 25,059 82.292% 82.105% 100.000% 83.067% 80.701% 100.000%NHNJ 405 372 33 7,277,246 2,250,288 5,026,958 98.272% 98.925% 90.909% 83.353% 95.346% 77.985%NM 566 533 33 1,613,612 1,348,169 265,443 97.880% 97.749% 100.000% 99.918% 99.902% 100.000%NV 103 96 7 798,524 149,909 648,615 77.670% 77.083% 85.714% 97.266% 90.972% 98.720%NY 191 152 39 530,912 70,933 459,979 78.010% 78.947% 74.359% 35.338% 72.079% 29.672%OH 1,035 915 120 9,786,781 2,902,824 6,883,957 20.580% 21.093% 16.667% 14.547% 16.022% 13.925%OKOR 575 452 123 2,505,059 408,312 2,096,747 13.217% 14.159% 9.756% 12.623% 19.033% 11.375%RI 64 56 8 885,894 146,456 739,438 93.750% 94.643% 87.500% 98.668% 97.478% 98.903%SC 452 405 47 3,021,859 525,705 2,496,154 65.044% 66.420% 53.191% 69.265% 83.408% 66.286%SD 251 230 21 639,064 279,893 359,171 84.064% 85.217% 71.429% 86.924% 85.717% 87.864%TN 344 157 187 5,678,451 1,460,345 4,218,106 95.349% 97.452% 93.583% 95.964% 99.217% 94.837%TX 3,989 3,662 327 24,786,365 9,009,970 15,776,395 57.458% 59.776% 31.498% 51.756% 71.833% 40.290%UT 416 369 47 2,512,399 1,655,292 857,107 80.769% 83.740% 57.447% 92.487% 94.516% 88.567%VA 395 320 75 3,339,718 158,335 3,181,383 86.582% 86.563% 86.667% 93.945% 92.600% 94.012%VT 364 322 42 452,258 186,370 265,888 78.022% 79.503% 66.667% 66.265% 73.777% 60.999%WIWV 351 203 148 1,408,492 238,737 1,169,755 88.319% 90.148% 85.811% 91.622% 82.050% 93.576%WY 223 186 37 430,065 116,596 313,469 62.332% 63.978% 54.054% 63.270% 71.519% 60.201%Total 18,653 16,467 2,186 121,170,400 40,744,045 80,426,355 68.080% 69.242% 59.332% 68.542% 78.754% 63.369%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A2c. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 6 6 0 1.869% 2.390% 0.000% 68,784 68,784 0 1.468% 4.732% 0.000%ARAZ 3 3 0 0.422% 0.446% 0.000% 5,284 5,284 0 0.090% 0.211% 0.000%CACO 28 25 3 7.053% 8.306% 3.125% 162,838 51,638 111,200 4.196% 16.533% 3.116%CT 14 14 0 2.972% 3.196% 0.000% 2,545 2,545 0 0.106% 1.105% 0.000%DEFL 6 6 0 2.899% 3.141% 0.000% 12,361 12,361 0 0.156% 0.209% 0.000%GAHIIA 12 12 0 60.000% 60.000% 24,241 24,241 0 82.946% 82.946%ID 39 38 1 8.864% 9.246% 3.448% 346,720 160,720 186,000 41.181% 26.012% 83.005%ILIN 0 0 0 0.000% 0.000% 0 0 0 0.000% 0.000%KY 1 0 1 0.483% 0.000% 0.714% 1,040 0 1,040 0.023% 0.000% 0.025%MAMD 15 14 1 2.907% 3.050% 1.754% 322,589 317,489 5,100 6.595% 35.325% 0.128%ME 28 27 1 7.568% 8.359% 2.128% 5,253 4,650 603 0.857% 2.193% 0.150%MI 7 7 0 0.582% 0.611% 0.000% 10,017 10,017 0 0.149% 0.581% 0.000%MN 77 77 0 8.351% 8.565% 0.000% 550,631 550,631 0 13.535% 19.511% 0.000%MO 28 28 0 9.756% 10.606% 0.000% 67,083 67,083 0 10.409% 16.703% 0.000%MT 3 3 0 0.475% 0.523% 0.000% 2,689 2,689 0 0.379% 0.851% 0.000%NC 86 86 0 4.710% 5.077% 0.000% 49,231 49,231 0 0.719% 3.110% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 21 21 0 21.875% 22.105% 0.000% 57,320 57,320 0 28.044% 31.962% 0.000%NHNJ 63 58 5 15.556% 15.591% 15.152% 1,848,268 520,598 1,327,670 25.398% 23.135% 26.411%NM 84 83 1 14.841% 15.572% 3.030% 242,067 169,366 72,701 15.002% 12.563% 27.389%NV 5 5 0 4.854% 5.208% 0.000% 1,409 1,409 0 0.176% 0.940% 0.000%NY 2 2 0 1.047% 1.316% 0.000% 500 500 0 0.094% 0.705% 0.000%OH 1 1 0 0.097% 0.109% 0.000% 460 460 0 0.005% 0.016% 0.000%OKOR 1 1 0 0.174% 0.221% 0.000% 28 28 0 0.001% 0.007% 0.000%RI 5 5 0 7.813% 8.929% 0.000% 2,292 2,292 0 0.259% 1.565% 0.000%SC 26 24 2 5.752% 5.926% 4.255% 56,493 23,551 32,942 1.869% 4.480% 1.320%SD 5 5 0 1.992% 2.174% 0.000% 1,153 1,153 0 0.180% 0.412% 0.000%TN 2 2 0 0.581% 1.274% 0.000% 1,387 1,387 0 0.024% 0.095% 0.000%TX 236 231 5 5.916% 6.308% 1.529% 3,412,280 548,335 2,863,945 13.767% 6.086% 18.153%UT 19 18 1 4.567% 4.878% 2.128% 250,066 227,066 23,000 9.953% 13.718% 2.683%VA 7 7 0 1.772% 2.188% 0.000% 5,601 5,601 0 0.168% 3.537% 0.000%VT 14 14 0 3.846% 4.348% 0.000% 2,528 2,528 0 0.559% 1.356% 0.000%WIWV 1 1 0 0.285% 0.493% 0.000% 25 25 0 0.002% 0.010% 0.000%WY 9 8 1 4.036% 4.301% 2.703% 9,627 2,777 6,850 2.238% 2.382% 2.185%

Total 854 832 22 4.578% 5.053% 1.006% 7,522,810 2,891,759 4,631,051 6.208% 7.097% 5.758%

Percent of Population Served 

with At Least One Detection 

> 15 pCi/L

State

Number of Systems 

with At Least One Detection 

> 15 pCi/L

Percent of Systems 

with At Least One Detection 

> 15 pCi/L

Population Served by Systems 

with At Least One Detection 

> 15 pCi/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A2d. Alpha Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 3 3 0 1.136% 1.554% 0.000% 580 580 0 0.121% 0.351% 0.000%AL 15 14 1 4.673% 5.578% 1.429% 161,148 138,425 22,723 3.438% 9.524% 0.703%ARAZ 161 153 8 22.644% 22.734% 21.053% 3,146,257 730,282 2,415,975 53.683% 29.131% 72.033%CACO 67 59 8 16.877% 19.601% 8.333% 356,466 118,756 237,710 9.185% 38.022% 6.661%CT 64 63 1 13.588% 14.384% 3.030% 23,602 11,371 12,231 0.987% 4.938% 0.566%DEFL 24 24 0 11.594% 12.565% 0.000% 108,916 108,916 0 1.371% 1.844% 0.000%GAHIIA 18 18 0 90.000% 90.000% 0.000% 27,778 27,778 0 95.049% 95.049% 0.000%ID 78 76 2 17.727% 18.491% 6.897% 472,365 272,313 200,052 56.104% 44.073% 89.275%ILIN 1 1 0 3.030% 3.030% 0.000% 378 378 0 0.385% 0.385% 0.000%KY 9 6 3 4.348% 8.955% 2.143% 82,598 12,999 69,599 1.800% 3.548% 1.649%MAMD 51 48 3 9.884% 10.458% 5.263% 401,985 393,864 8,121 8.218% 43.822% 0.203%ME 50 48 2 13.514% 14.861% 4.255% 17,242 15,576 1,666 2.814% 7.345% 0.416%MI 49 48 1 4.073% 4.188% 1.754% 57,231 47,358 9,873 0.852% 2.748% 0.198%MN 230 230 0 24.946% 25.584% 0.000% 1,323,952 1,323,952 0 32.545% 46.912% 0.000%MO 51 51 0 17.770% 19.318% 0.000% 96,303 96,303 0 14.944% 23.979% 0.000%MT 54 51 3 8.558% 8.885% 5.263% 29,275 25,030 4,245 4.131% 7.917% 1.082%NC 169 169 0 9.255% 9.976% 0.000% 100,325 100,325 0 1.466% 6.337% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 44 43 1 45.833% 45.263% 100.000% 117,873 92,814 25,059 57.669% 51.754% 100.000%NHNJ 111 104 7 27.407% 27.957% 21.212% 2,576,578 967,842 1,608,736 35.406% 43.010% 32.002%NM 181 178 3 31.979% 33.396% 9.091% 972,017 887,256 84,761 60.239% 65.812% 31.932%NV 6 6 0 5.825% 6.250% 0.000% 2,649 2,649 0 0.332% 1.767% 0.000%NY 8 8 0 4.188% 5.263% 0.000% 1,266 1,266 0 0.238% 1.785% 0.000%OH 22 22 0 2.126% 2.404% 0.000% 25,084 25,084 0 0.256% 0.864% 0.000%OKOR 3 2 1 0.522% 0.442% 0.813% 11,238 98 11,140 0.449% 0.024% 0.531%RI 12 12 0 18.750% 21.429% 0.000% 6,756 6,756 0 0.763% 4.613% 0.000%SC 61 58 3 13.496% 14.321% 6.383% 122,375 48,883 73,492 4.050% 9.299% 2.944%SD 36 34 2 14.343% 14.783% 9.524% 220,006 27,897 192,109 34.426% 9.967% 53.487%TN 4 4 0 1.163% 2.548% 0.000% 9,985 9,985 0 0.176% 0.684% 0.000%TX 819 797 22 20.531% 21.764% 6.728% 6,468,010 2,165,740 4,302,270 26.095% 24.037% 27.270%UT 92 82 10 22.115% 22.222% 21.277% 1,300,123 624,172 675,951 51.748% 37.708% 78.864%VA 24 24 0 6.076% 7.500% 0.000% 17,665 17,665 0 0.529% 11.157% 0.000%VT 42 41 1 11.538% 12.733% 2.381% 15,372 12,412 2,960 3.399% 6.660% 1.113%WIWV 11 11 0 3.134% 5.419% 0.000% 1,113 1,113 0 0.079% 0.466% 0.000%WY 26 23 3 11.659% 12.366% 8.108% 86,883 7,662 79,221 20.202% 6.571% 25.272%Total 2,596 2,511 85 13.917% 15.249% 3.888% 18,361,394 8,323,500 10,037,894 15.153% 20.429% 12.481%

Percent of Population Served 

with At Least One Detection 


	


State

Number of Systems 

with At Least One Detection 


	


Percent of Systems 

with At Least One Detection 


	


Population Served by Systems 

with At Least One Detection 


	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A3. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.006 mg/L 44,971 97 0.216% 85,727,750 251,693 0.294%	
 44,971 512 1.139% 85,727,750 1,812,718 2.115%

> 0.006 mg/L 4,045 33 0.816% 137,523,912 3,108,813 2.261%

	
 4,045 117 2.892% 137,523,912 10,308,814 7.496%

> 0.006 mg/L 49,016 130 0.265% 223,251,662 3,360,506 1.505%

	
 49,016 629 1.283% 223,251,662 12,121,532 5.430%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A3a. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 1,497 1,061 436 1.403% 1.414% 1.376% 0.00007 0.00012 0.00007 0.00139 0.00207 0.00048 0.004 0.004 0.003 0.00523 0.00523 0.003AL 2,631 1,790 841 0.646% 0.559% 0.832% 0.0012 0.002 0.0012 0.003 0.003 0.003 0.00775 0.00688 0.01 0.01 0.00775 0.01AR 2,308 1,644 664 0.433% 0.304% 0.753% 0.0012 0.0019 0.0012 0.002 0.004 0.002 0.004 0.004 0.003 0.004 0.004 0.003AZ 6,299 4,997 1,302 1.000% 1.041% 0.845% 0.0001 0.0001 0.0007 0.003 0.00315 0.0012 0.005 0.005 0.0037 0.0091 0.0091 0.004CA 35,219 20,956 14,263 1.005% 1.131% 0.820% 4.1E-05 4.1E-05 4.2E-05 0.00058 0.001 0.00029 0.01 0.01 0.009 0.05 0.05 0.04CO 4,369 2,326 2,043 3.662% 3.396% 3.965% 0.00005 0.00035 0.00005 0.001 0.001 0.001 0.004 0.004 0.0037 0.02 0.02 0.006CT 2,229 1,839 390 2.064% 2.121% 1.795% 0.0003 0.0003 0.0006 0.002 0.002 0.0009 0.006 0.006 0.06 0.06 0.006 0.06DE 686 638 48 3.353% 2.978% 8.333% 0.0001 0.0001 0.0001 0.0002 0.0002 0.0001 0.0024 0.0035 0.0007 0.004 0.004 0.0007FL 2,142 2,073 69 6.303% 6.175% 10.145% 0.0001 0.0001 0.0002 0.0015 0.00125 0.002 0.0038 0.0039 0.0036 0.006 0.006 0.0036GA 2,711 2,388 323 0.037% 0.042% 0.000% 0.0053 0.0053 0.0053 0.0053 0.0053 0.0053 0.0053 0.0053HI 1,173 1,112 61 0.000% 0.000% 0.000%IA 1,484 1,222 262 0.270% 0.164% 0.763% 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002ID 3,106 2,806 300 1.996% 1.924% 2.667% 9.5E-05 9.5E-05 0.001 0.001 0.001 0.0035 0.004 0.003 0.005 0.006 0.006 0.005IL 2,763 2,364 399 0.362% 0.423% 0.000% 0.0022 0.0022 0.00305 0.00305 0.023 0.023 0.04 0.04IN 4,729 4,248 481 2.072% 1.836% 4.158% 6.1E-05 6.1E-05 0.0003 0.00072 0.0009 0.00049 0.0048 0.005 0.0022 0.03 0.03 0.003KY 1,799 551 1,248 5.447% 4.537% 5.849% 0.0002 0.001 0.0002 0.002 0.0025 0.002 0.005 0.005 0.004 0.05 0.0069 0.05MA 2,961 1,986 975 2.060% 2.115% 1.949% 0.0002 0.0002 0.0002 0.002 0.002 0.0021 0.006 0.004 0.0061 0.01 0.01 0.0081MD 5,069 3,964 1,105 1.282% 0.555% 3.891% 0.00022 0.00022 0.0005 0.002 0.005 0.001 0.0059 0.009 0.003 0.01 0.01 0.01ME 2,392 2,002 390 6.982% 7.942% 2.051% 0.0005 0.0005 0.0005 0.0021 0.0021 0.0024 0.01 0.01 0.01 0.06 0.06 0.01MI 6,738 6,559 179 24.117% 22.503% 83.240% 0.0001 0.0001 0.0001 0.0001 0.0001 0.0002 0.0004 0.0004 0.0003 0.05 0.05 0.0007MN 4,436 4,357 79 2.570% 2.594% 1.266% 0.0006 0.0006 0.00097 0.00082 0.00081 0.00097 0.00189 0.00189 0.00097 0.0051 0.0051 0.00097MO 5,705 4,927 778 0.403% 0.365% 0.643% 0.00101 0.00106 0.00101 0.00135 0.00139 0.00112 0.0031 0.0032 0.00163 0.00441 0.00441 0.00163MT 3,229 2,889 340 1.394% 1.488% 0.588% 0.0004 0.0004 0.001 0.002 0.002 0.0025 0.02 0.02 0.004 0.03 0.03 0.004NC 9,282 7,830 1,452 1.767% 1.252% 4.545% 0.0002 0.0002 0.0002 0.0027 0.003 0.001 0.005 0.005 0.004 0.02 0.02 0.0083ND 345 303 42 0.000% 0.000% 0.000%NE 2,988 2,879 109 1.406% 1.459% 0.000% 0.0002 0.0002 0.00121 0.00121 0.00548 0.00548 0.00733 0.00733NH 2,951 2,787 164 1.491% 1.579% 0.000% 0.0005 0.0005 0.003 0.003 0.0065 0.0065 0.01 0.01NJ 6,572 5,846 726 0.943% 0.872% 1.515% 0.0004 0.0007 0.0004 0.002 0.002 0.002 0.0069 0.007 0.003 0.05 0.05 0.0032NM 3,517 3,191 326 1.422% 1.442% 1.227% 0.00006 0.00006 0.0005 0.001 0.001 0.0013 0.0055 0.006 0.003 0.04 0.04 0.003NV 2,162 1,629 533 9.019% 11.234% 2.251% 0.0003 0.0003 0.001 0.003 0.003 0.002 0.01 0.01 0.003 0.04 0.04 0.005NY 3,307 2,509 798 2.328% 2.352% 2.256% 0.0001 0.00011 0.0001 0.0013 0.0018 0.00074 0.006 0.005 0.007 0.01 0.01 0.01OH 4,636 4,002 634 0.647% 0.625% 0.789% 0.0004 0.00153 0.0004 0.0031 0.0032 0.003 0.00502 0.0054 0.0043 0.0088 0.0088 0.0043OK 420 346 74 0.714% 0.578% 1.351% 0.0012 0.0012 0.0028 0.002 0.0016 0.0028 0.0028 0.002 0.0028 0.0028 0.002 0.0028OR 1,315 953 362 0.760% 0.420% 1.657% 0.0001 0.002 0.0001 0.0018 0.00275 0.00014 0.0045 0.006 0.0024 0.006 0.006 0.0024RI 857 629 228 0.933% 0.954% 0.877% 0.002 0.002 0.002 0.002 0.002 0.0035 0.005 0.004 0.005 0.005 0.004 0.005SC 3,433 2,970 463 0.524% 0.606% 0.000% 0.003 0.003 0.00825 0.00825 0.03 0.03 0.04 0.04SD 384 357 27 7.031% 6.443% 14.815% 0.0002 0.0002 0.0003 0.0006 0.001 0.00035 0.002 0.002 0.0004 0.005 0.005 0.0004TN 1,830 637 1,193 11.475% 1.099% 17.016% 0.0003 0.0011 0.0003 0.002 0.0014 0.002 0.00335 0.0068 0.0033 0.0068 0.0068 0.0056TX 14,756 12,177 2,579 0.149% 0.123% 0.271% 0.00105 0.00105 0.00121 0.00153 0.0017 0.00133 0.003 0.003 0.0053 0.0053 0.0035 0.0053UT 7,395 5,597 1,798 11.494% 6.110% 28.254% 0.0001 0.0001 0.0003 0.0058 0.0058 0.0059 0.0084 0.0071 0.0085 0.01 0.01 0.01VA 2,804 2,196 608 0.285% 0.319% 0.164% 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002VT 2,117 1,772 345 0.756% 0.903% 0.000% 0.00048 0.00048 0.003 0.003 0.01 0.01 0.01 0.01WI 7,006 6,835 171 3.754% 3.599% 9.942% 4.2E-05 4.2E-05 0.0002 0.00101 0.0011 0.0003 0.0032 0.0033 0.0006 0.03 0.03 0.0026WV 1,109 422 687 2.976% 5.213% 1.601% 0.00021 0.00029 0.00021 0.005 0.005 0.0025 0.005 0.005 0.005 0.006 0.005 0.006WY 1,125 875 250 0.533% 0.571% 0.400% 0.001 0.001 0.0013 0.00165 0.002 0.0013 0.006 0.006 0.0013 0.006 0.006 0.0013Total 185,986 145,441 40,545 2.871% 2.673% 3.581% 4.1E-05 4.1E-05 4.2E-05 0.001 0.00079 0.00155 0.006 0.006 0.0071 0.06 0.06 0.06

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A3b. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 609 467 142 592,810 230,950 361,860 3.448% 3.212% 4.225% 1.523% 1.876% 1.297%AL 352 279 73 4,701,100 1,463,066 3,238,034 2.841% 1.792% 6.849% 17.155% 1.874% 24.059%AR 453 381 72 2,452,800 909,774 1,543,026 1.545% 0.787% 5.556% 3.471% 0.225% 5.384%AZ 1,052 1,004 48 6,159,405 2,788,814 3,370,591 4.753% 4.582% 8.333% 35.270% 11.424% 55.000%CA 3,819 3,294 525 36,232,443 13,516,569 22,715,874 3.640% 3.066% 7.238% 15.551% 16.235% 15.144%CO 837 616 221 4,996,481 531,250 4,465,231 12.664% 8.766% 23.529% 31.345% 14.389% 33.362%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 3.333% 3.006% 12.821% 19.393% 4.647% 21.809%DE 281 278 3 679,823 398,423 281,400 7.473% 6.475% 100.000% 51.005% 16.400% 100.000%FL 1,332 1,306 26 17,247,583 15,001,541 2,246,042 7.808% 7.580% 19.231% 35.873% 36.321% 32.877%GA 1,592 1,478 114 7,239,616 1,347,285 5,892,331 0.063% 0.068% 0.000% 0.001% 0.003% 0.000%HI 107 95 12 1,303,767 1,249,139 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 965 932 33 2,499,680 1,391,054 1,108,626 0.415% 0.215% 6.061% 1.295% 1.957% 0.463%ID 924 875 49 1,078,426 833,516 244,910 5.303% 5.371% 4.082% 9.112% 11.749% 0.139%IL 1,241 1,140 101 9,078,639 2,879,411 6,199,228 0.806% 0.877% 0.000% 0.308% 0.971% 0.000%IN 1,621 1,572 49 4,977,274 2,616,819 2,360,455 4.874% 4.326% 22.449% 24.214% 8.574% 41.553%KY 242 93 149 4,602,489 375,460 4,227,029 28.512% 22.581% 32.215% 24.825% 13.184% 25.859%MA 676 558 118 8,525,575 1,718,151 6,807,424 6.065% 5.197% 10.169% 47.453% 3.991% 58.423%MD 1,037 969 68 5,022,431 1,024,324 3,998,107 2.314% 2.064% 5.882% 36.562% 1.598% 45.520%ME 802 748 54 727,134 291,530 435,604 7.980% 8.155% 5.556% 3.441% 4.237% 2.909%MI 3,032 2,979 53 6,717,080 1,924,649 4,792,431 38.061% 37.160% 88.679% 86.541% 55.110% 99.164%MN 1,593 1,564 29 4,265,162 3,015,521 1,249,641 6.340% 6.394% 3.448% 5.268% 6.290% 2.803%MO 1,420 1,343 77 3,006,718 1,692,257 1,314,461 1.479% 1.266% 5.195% 7.403% 1.860% 14.541%MT 849 789 60 757,930 365,261 392,669 2.591% 2.535% 3.333% 15.403% 23.425% 7.941%NC 2,284 2,145 139 6,973,609 1,708,443 5,265,166 5.298% 4.103% 23.741% 28.279% 7.510% 35.019%ND 217 190 27 563,069 257,844 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 743 732 11 1,450,223 673,743 776,480 2.557% 2.596% 0.000% 3.226% 6.945% 0.000%NH 1,216 1,175 41 942,517 392,718 549,799 1.563% 1.617% 0.000% 3.278% 7.867% 0.000%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 3.057% 2.842% 10.811% 22.689% 11.628% 28.678%NM 724 685 39 1,667,433 1,400,885 266,548 5.110% 4.818% 10.256% 7.416% 3.203% 29.557%NV 335 314 21 973,342 283,451 689,891 17.313% 16.561% 28.571% 53.728% 42.017% 58.540%NY 1,548 1,312 236 4,385,092 1,212,438 3,172,654 3.941% 3.430% 6.780% 6.185% 4.036% 7.006%OH 1,929 1,804 125 10,221,998 3,127,061 7,094,937 1.555% 1.386% 4.000% 2.006% 0.407% 2.711%OK 202 175 27 749,266 276,712 472,554 1.485% 1.143% 3.704% 6.051% 8.266% 4.754%OR 731 610 121 2,770,064 486,818 2,283,246 1.094% 0.656% 3.306% 4.843% 0.109% 5.852%RI 142 133 9 913,384 173,406 739,978 5.634% 4.511% 22.222% 53.119% 3.956% 64.640%SC 823 758 65 3,468,333 809,806 2,658,527 0.972% 1.055% 0.000% 1.200% 5.140% 0.000%SD 234 223 11 339,259 247,298 91,961 10.256% 9.865% 18.182% 6.557% 7.620% 3.697%TN 351 162 189 5,685,258 1,462,502 4,222,756 4.558% 3.704% 5.291% 11.093% 7.998% 12.165%TX 4,888 4,547 341 25,060,220 9,275,719 15,784,501 0.368% 0.286% 1.466% 6.176% 14.181% 1.471%UT 507 457 50 2,543,652 1,686,017 857,635 13.412% 12.473% 22.000% 43.925% 32.136% 67.101%VA 1,582 1,414 168 4,803,450 634,384 4,169,066 0.379% 0.354% 0.595% 0.113% 0.456% 0.061%VT 601 558 43 490,989 227,021 263,968 1.830% 1.971% 0.000% 0.353% 0.764% 0.000%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 11.135% 10.871% 35.000% 42.715% 25.323% 66.903%WV 452 291 161 1,416,939 236,149 1,180,790 6.416% 7.560% 4.348% 2.054% 1.543% 2.156%WY 304 255 49 446,184 129,168 317,016 1.645% 1.569% 2.041% 8.059% 1.027% 10.925%Total 49,016 44,971 4,045 223,251,662 85,727,750 137,523,912 5.978% 5.677% 9.320% 19.208% 15.708% 21.390%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A3c. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 3 1 2 0.852% 0.358% 2.740% 56,892 600 56,292 1.210% 0.041% 1.738%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.095% 0.100% 0.000% 19,760 19,760 0 0.321% 0.709% 0.000%CA 45 30 15 1.178% 0.911% 2.857% 1,089,681 140,298 949,383 3.007% 1.038% 4.179%CO 3 3 0 0.358% 0.487% 0.000% 1,723 1,723 0 0.034% 0.324% 0.000%CT 1 0 1 0.085% 0.000% 2.564% 58,691 0 58,691 2.161% 0.000% 2.515%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.081% 0.088% 0.000% 15,933 15,933 0 0.175% 0.553% 0.000%IN 2 2 0 0.123% 0.127% 0.000% 425 425 0 0.009% 0.016% 0.000%KY 3 1 2 1.240% 1.075% 1.342% 61,163 6,161 55,002 1.329% 1.641% 1.301%MA 3 1 2 0.444% 0.179% 1.695% 110,521 7,000 103,521 1.296% 0.407% 1.521%MD 4 3 1 0.386% 0.310% 1.471% 1,711,370 1,370 1,710,000 34.075% 0.134% 42.770%ME 7 6 1 0.873% 0.802% 1.852% 2,571 771 1,800 0.354% 0.264% 0.413%MI 1 1 0 0.033% 0.034% 0.000% 50 50 0 0.001% 0.003% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 2 2 0 0.236% 0.253% 0.000% 1,090 1,090 0 0.144% 0.298% 0.000%NC 6 4 2 0.263% 0.186% 1.439% 27,114 3,230 23,884 0.389% 0.189% 0.454%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 1 1 0 0.135% 0.137% 0.000% 1,640 1,640 0 0.113% 0.243% 0.000%NH 4 4 0 0.329% 0.340% 0.000% 6,224 6,224 0 0.660% 1.585% 0.000%NJ 6 6 0 0.437% 0.449% 0.000% 1,425 1,425 0 0.018% 0.052% 0.000%NM 3 3 0 0.414% 0.438% 0.000% 15,846 15,846 0 0.950% 1.131% 0.000%NV 6 6 0 1.791% 1.911% 0.000% 6,599 6,599 0 0.678% 2.328% 0.000%NY 7 4 3 0.452% 0.305% 1.271% 130,032 1,315 128,717 2.965% 0.108% 4.057%OH 1 1 0 0.052% 0.055% 0.000% 255 255 0 0.002% 0.008% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 3 3 0 0.365% 0.396% 0.000% 758 758 0 0.022% 0.094% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 1 0 0.285% 0.617% 0.000% 12,703 12,703 0 0.223% 0.869% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 11 7 4 2.170% 1.532% 8.000% 27,423 5,900 21,523 1.078% 0.350% 2.510%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 2 2 0 0.333% 0.358% 0.000% 70 70 0 0.014% 0.031% 0.000%WI 3 3 0 0.165% 0.166% 0.000% 547 547 0 0.014% 0.023% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 130 97 33 0.265% 0.216% 0.816% 3,360,506 251,693 3,108,813 1.505% 0.294% 2.261%

Percent of Population Served 

with At Least One Detection 

> 0.006 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.006 mg/L

Percent of Systems 

with At Least One Detection 

> 0.006 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.006 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A3d. Antimony – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 8 7 1 1.314% 1.499% 0.704% 2,610 2,260 350 0.440% 0.979% 0.097%AL 6 2 4 1.705% 0.717% 5.479% 130,152 12,559 117,593 2.769% 0.858% 3.632%AR 3 2 1 0.662% 0.525% 1.389% 72,873 1,712 71,161 2.971% 0.188% 4.612%AZ 30 28 2 2.852% 2.789% 4.167% 330,593 150,343 180,250 5.367% 5.391% 5.348%CA 63 45 18 1.650% 1.366% 3.429% 1,682,895 285,175 1,397,720 4.645% 2.110% 6.153%CO 23 14 9 2.748% 2.273% 4.072% 181,666 27,520 154,146 3.636% 5.180% 3.452%CT 17 15 2 1.453% 1.326% 5.128% 68,787 6,964 61,823 2.532% 1.822% 2.649%DE 2 2 0 0.712% 0.719% 0.000% 5,120 5,120 0 0.753% 1.285% 0.000%FL 30 29 1 2.252% 2.221% 3.846% 323,928 222,045 101,883 1.878% 1.480% 4.536%GA 1 1 0 0.063% 0.068% 0.000% 46 46 0 0.001% 0.003% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 12 10 2 1.299% 1.143% 4.082% 43,912 43,572 340 4.072% 5.227% 0.139%IL 9 9 0 0.725% 0.789% 0.000% 27,626 27,626 0 0.304% 0.959% 0.000%IN 18 17 1 1.110% 1.081% 2.041% 30,392 19,322 11,070 0.611% 0.738% 0.469%KY 31 12 19 12.810% 12.903% 12.752% 327,962 26,330 301,632 7.126% 7.013% 7.136%MA 20 13 7 2.959% 2.330% 5.932% 3,886,128 57,204 3,828,924 45.582% 3.329% 56.246%MD 20 17 3 1.929% 1.754% 4.412% 1,834,740 14,983 1,819,757 36.531% 1.463% 45.515%ME 18 16 2 2.244% 2.139% 3.704% 4,950 2,087 2,863 0.681% 0.716% 0.657%MI 15 15 0 0.495% 0.504% 0.000% 5,076 5,076 0 0.076% 0.264% 0.000%MN 3 3 0 0.188% 0.192% 0.000% 12,007 12,007 0 0.282% 0.398% 0.000%MO 3 3 0 0.211% 0.223% 0.000% 941 941 0 0.031% 0.056% 0.000%MT 8 7 1 0.942% 0.887% 1.667% 41,212 10,057 31,155 5.437% 2.753% 7.934%NC 69 55 14 3.021% 2.564% 10.072% 213,352 76,540 136,812 3.059% 4.480% 2.598%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 3 3 0 0.404% 0.410% 0.000% 27,327 27,327 0 1.884% 4.056% 0.000%NH 13 13 0 1.069% 1.106% 0.000% 7,859 7,859 0 0.834% 2.001% 0.000%NJ 18 16 2 1.310% 1.197% 5.405% 1,104,325 29,253 1,075,072 14.227% 1.073% 21.348%NM 6 5 1 0.829% 0.730% 2.564% 92,536 19,835 72,701 5.550% 1.416% 27.275%NV 13 12 1 3.881% 3.822% 4.762% 24,859 16,559 8,300 2.554% 5.842% 1.203%NY 23 18 5 1.486% 1.372% 2.119% 165,959 36,652 129,307 3.785% 3.023% 4.076%OH 19 16 3 0.985% 0.887% 2.400% 95,509 5,289 90,220 0.934% 0.169% 1.272%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 2 2 0 0.274% 0.328% 0.000% 402 402 0 0.015% 0.083% 0.000%RI 3 2 1 2.113% 1.504% 11.111% 54,570 3,820 50,750 5.974% 2.203% 6.858%SC 8 8 0 0.972% 1.055% 0.000% 41,627 41,627 0 1.200% 5.140% 0.000%SD 2 2 0 0.855% 0.897% 0.000% 746 746 0 0.220% 0.302% 0.000%TN 5 1 4 1.425% 0.617% 2.116% 473,680 12,703 460,977 8.332% 0.869% 10.916%TX 3 2 1 0.061% 0.044% 0.293% 15,527 10,077 5,450 0.062% 0.109% 0.035%UT 41 33 8 8.087% 7.221% 16.000% 615,153 433,108 182,045 24.184% 25.688% 21.226%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 6 6 0 0.998% 1.075% 0.000% 880 880 0 0.179% 0.388% 0.000%WI 34 34 0 1.865% 1.886% 0.000% 154,129 154,129 0 3.811% 6.551% 0.000%WV 20 16 4 4.425% 5.498% 2.484% 19,416 2,903 16,513 1.370% 1.229% 1.398%WY 1 1 0 0.329% 0.392% 0.000% 60 60 0 0.013% 0.046% 0.000%Total 629 512 117 1.283% 1.139% 2.892% 12,121,532 1,812,718 10,308,814 5.430% 2.115% 7.496%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A4. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration or 

Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.05 mg/L 45,387 346 0.762% 85,737,044 1,352,250 1.577%

	
 45,387 1,216 2.679% 85,737,044 3,901,453 4.550%

> 0.01 mg/L 45,387 3,364 7.412% 85,737,044 8,655,516 10.095%

	
 45,387 7,859 17.316% 85,737,044 18,464,077 21.536%

> 0.05 mg/L 4,086 25 0.612% 144,656,184 1,503,598 1.039%

	
 4,086 55 1.346% 144,656,184 7,158,650 4.949%

> 0.01 mg/L 4,086 152 3.720% 144,656,184 15,741,605 10.882%

	
 4,086 369 9.031% 144,656,184 28,990,530 20.041%

> 0.05 mg/L 49,473 371 0.750% 230,393,228 2,855,848 1.240%

	
 49,473 1,271 2.569% 230,393,228 11,060,103 4.801%

> 0.01 mg/L 49,473 3,516 7.107% 230,393,228 24,397,121 10.589%

	
 49,473 8,228 16.631% 230,393,228 47,454,607 20.597%

Combined Ground & 

Ground Water

Surface Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A4a. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 2084 1393 691 33.541% 42.355% 15.774% 0.00016 0.00017 0.00016 0.007 0.008 0.00145 0.03 0.03 0.01 0.18 0.18 0.15AL 2670 1814 856 1.423% 1.323% 1.636% 0.0001 0.00049 0.0001 0.00179 0.00199 0.00146 0.01 0.01 0.006 0.05 0.05 0.0069AR 2221 1567 654 1.981% 2.680% 0.306% 0.0017 0.0017 0.0021 0.0033 0.0033 0.00405 0.0098 0.0098 0.006 0.03 0.03 0.006AZ 7709 6165 1544 70.567% 68.532% 78.692% 0.0005 0.0005 0.0005 0.007 0.007 0.0069 0.02 0.03 0.01 0.25 0.25 0.13CA 51056 32918 18138 50.061% 58.664% 34.447% 9.3E-05 9.3E-05 0.00023 0.005 0.006 0.0033 0.02 0.02 0.01 0.39 0.39 0.26CO 4447 2426 2021 19.271% 27.288% 9.649% 0.00006 0.0001 0.00006 0.0033 0.005 0.00134 0.04 0.05 0.005 0.09 0.09 0.01CT 2606 1883 723 3.761% 4.886% 0.830% 0.0007 0.001 0.0007 0.008 0.00918 0.0014 0.04 0.04 0.003 0.07 0.07 0.003DE 786 738 48 44.784% 44.715% 45.833% 0.0001 0.0001 0.0001 0.0009 0.001 0.0005 0.009 0.009 0.0016 0.04 0.04 0.01FL 2171 2100 71 20.405% 20.714% 11.268% 0.0001 0.0001 0.0005 0.0019 0.0019 0.0017 0.009 0.0091 0.009 0.24 0.24 0.009GA 2706 2382 324 1.293% 1.469% 0.000% 0.0051 0.0051 0.0071 0.0071 0.01 0.01 0.06 0.06HI 1177 1115 62 0.000% 0.000% 0.000%IA 3008 2682 326 32.148% 32.364% 30.368% 0.0009 0.0009 0.001 0.003 0.004 0.001 0.02 0.02 0.003 0.27 0.27 0.005ID 4655 3877 778 33.319% 35.414% 22.879% 0.0001 0.0002 0.0001 0.007 0.008 0.006 0.02 0.02 0.01 0.48 0.48 0.07IL 3444 3044 400 51.249% 52.102% 44.750% 5.8E-05 5.8E-05 0.0005 0.0034 0.00465 0.001 0.02 0.02 0.002 0.12 0.12 0.04IN 4914 4425 489 27.859% 29.740% 10.838% 0.0003 0.0005 0.0003 0.0044 0.0046 0.0017 0.01 0.01 0.0053 0.07 0.07 0.02KY 1772 535 1237 6.546% 5.794% 6.871% 0.00041 0.0005 0.00041 0.003 0.004 0.002 0.008 0.008 0.008 0.01 0.01 0.01MA 3845 2647 1198 16.619% 18.549% 12.354% 0.0004 0.0005 0.0004 0.01 0.01 0.006 0.04 0.04 0.02 0.08 0.08 0.05MD 5296 4178 1118 19.279% 22.451% 7.424% 0.0001 0.0006 0.0001 0.007 0.00765 0.001 0.01 0.01 0.002 0.25 0.25 0.005ME 3260 2857 403 57.025% 62.023% 21.588% 0.0005 0.0005 0.0005 0.005 0.005 0.0007 0.02 0.02 0.005 0.39 0.39 0.02MI 13055 12835 220 78.192% 78.255% 74.545% 0.0001 0.0001 0.0002 0.005 0.005 0.001 0.02 0.02 0.003 0.43 0.43 0.02MN 5604 5524 80 52.052% 52.679% 8.750% 0.001 0.001 0.00104 0.0044 0.0044 0.0013 0.02 0.02 0.00344 0.07 0.07 0.00344MO 5718 4937 781 8.569% 7.839% 13.188% 0.001 0.001 0.001 0.00145 0.00153 0.0013 0.00486 0.005 0.0026 0.03 0.03 0.01MT 3530 3031 499 25.297% 26.658% 17.034% 0.0004 0.0004 0.001 0.002 0.002 0.003 0.01 0.01 0.02 0.11 0.11 0.1NC 9288 7838 1450 1.981% 2.143% 1.103% 0.0005 0.001 0.0005 0.006 0.006 0.004 0.03 0.03 0.01 0.05 0.05 0.01ND 632 567 65 74.051% 76.014% 56.923% 0.001 0.001 0.001 0.0039 0.00416 0.00192 0.02 0.02 0.00547 0.15 0.15 0.01NE 2107 2023 84 76.222% 77.261% 51.190% 0.00013 0.00013 0.0021 0.00461 0.00462 0.00429 0.00889 0.009 0.0072 0.06 0.06 0.01NH 4265 4088 177 52.145% 53.694% 16.384% 0.0007 0.0007 0.001 0.01 0.01 0.0046 0.04 0.04 0.01 0.75 0.75 0.02NJ 6749 6017 732 7.453% 6.465% 15.574% 0.0001 0.0003 0.0001 0.0039 0.004 0.002 0.01 0.01 0.009 0.03 0.03 0.02NM 3680 3209 471 72.853% 75.382% 55.626% 0.0001 0.0001 0.0003 0.003 0.003 0.005 0.01 0.01 0.05 0.5 0.5 0.44NV 3622 2908 714 73.771% 75.138% 68.207% 0.00049 0.001 0.00049 0.0097 0.01 0.004 0.05 0.05 0.01 0.32 0.32 0.1NY 3498 2638 860 7.547% 7.619% 7.326% 0.0001 0.0001 0.001 0.005 0.007 0.0012 0.03 0.03 0.0031 0.19 0.19 0.01OH 5664 4731 933 24.629% 28.387% 5.573% 0.001 0.001 0.001 0.0096 0.0096 0.0076 0.05 0.04 0.12 0.42 0.12 0.42OK 431 351 80 37.819% 36.467% 43.750% 0.0015 0.0015 0.0016 0.0056 0.0045 0.01 0.04 0.03 0.07 0.1 0.08 0.1OR 2324 1634 690 31.454% 41.554% 7.536% 0.0005 0.0005 0.0005 0.0029 0.0029 0.003 0.01 0.01 0.01 0.17 0.17 0.02RI 948 713 235 6.857% 9.116% 0.000% 0.00011 0.00011 0.02 0.02 0.02 0.02 0.03 0.03SC 2100 1833 267 1.524% 1.746% 0.000% 0.0051 0.0051 0.01 0.01 0.05 0.05 0.09 0.09SD 328 313 15 47.866% 48.243% 40.000% 0.001 0.001 0.001 0.006 0.006 0.00195 0.01 0.01 0.002 0.02 0.02 0.002TN 1832 624 1208 4.694% 4.006% 5.050% 0.001 0.001 0.001 0.00395 0.0033 0.004 0.01 0.02 0.009 0.03 0.03 0.03TX 16814 14093 2721 34.311% 35.521% 28.041% 0.002 0.002 0.002 0.0045 0.005 0.0033 0.01 0.01 0.0078 0.18 0.18 0.03UT 7407 5822 1585 56.595% 56.905% 55.457% 0.0001 0.0003 0.0001 0.0027 0.0027 0.002 0.01 0.01 0.01 0.24 0.24 0.07VA 2830 2220 610 5.300% 6.667% 0.328% 0.002 0.002 0.002 0.004 0.004 0.0025 0.01 0.01 0.003 0.03 0.03 0.003VT 2299 1932 367 12.440% 14.700% 0.545% 0.001 0.001 0.001 0.004 0.004 0.0015 0.03 0.03 0.002 0.05 0.05 0.002WI 7143 6972 171 21.126% 21.285% 14.620% 0.00014 0.00014 0.0006 0.0034 0.0034 0.0011 0.00925 0.0093 0.0042 0.11 0.11 0.009WV 1196 481 715 4.599% 7.069% 2.937% 0.00007 0.0005 0.00007 0.0032 0.005 0.0005 0.01 0.01 0.0032 0.03 0.03 0.01WY 1144 884 260 11.014% 11.538% 9.231% 0.0007 0.001 0.0007 0.006 0.006 0.0065 0.01 0.01 0.01 0.04 0.04 0.03Total 224,035 176,964 47,071 36.904% 39.904% 25.627% 5.8E-05 5.8E-05 0.00006 0.005 0.00546 0.0033 0.02 0.02 0.01 0.75 0.75 0.44

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A4b. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 614 468 146 604,242 231,088 373,154 50.326% 52.778% 42.466% 73.802% 65.470% 78.962%AL 352 279 73 4,701,100 1,463,066 3,238,034 6.818% 5.018% 13.699% 7.438% 5.216% 8.442%AR 453 381 72 2,452,800 909,774 1,543,026 4.857% 5.249% 2.778% 3.678% 6.432% 2.055%AZ 1,057 1,009 48 6,163,221 2,792,630 3,370,591 88.363% 88.206% 91.667% 97.169% 93.839% 99.927%CA 3,860 3,336 524 36,251,169 13,421,000 22,830,169 56.114% 56.535% 53.435% 88.844% 83.209% 92.156%CO 830 609 221 4,995,552 530,321 4,465,231 33.494% 33.333% 33.937% 37.608% 42.476% 37.030%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 6.667% 6.543% 10.256% 7.420% 9.366% 7.101%DE 281 278 3 679,823 398,423 281,400 55.872% 55.396% 100.000% 76.466% 59.844% 100.000%FL 1,335 1,309 26 17,374,779 15,128,737 2,246,042 21.498% 21.467% 23.077% 48.773% 52.360% 24.610%GA 1,593 1,479 114 7,242,523 1,350,192 5,892,331 1.444% 1.555% 0.000% 0.408% 2.190% 0.000%HI 107 95 12 1,303,767 1,249,139 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,043 1,010 33 2,540,170 1,431,544 1,108,626 34.612% 33.267% 75.758% 47.546% 38.453% 59.288%ID 932 874 58 1,093,108 836,746 256,362 49.249% 50.686% 27.586% 70.646% 66.454% 84.331%IL 1,255 1,154 101 9,087,280 2,888,052 6,199,228 48.207% 46.360% 69.307% 80.802% 56.310% 92.212%IN 1,624 1,575 49 4,980,359 2,619,904 2,360,455 41.687% 41.651% 42.857% 47.869% 37.817% 59.027%KY 242 93 149 4,602,489 375,460 4,227,029 38.843% 26.882% 46.309% 58.296% 59.288% 58.208%MA 686 568 118 8,530,298 1,722,874 6,807,424 18.950% 18.838% 19.492% 54.989% 17.106% 64.577%MD 1,032 964 68 5,020,682 1,022,575 3,998,107 21.221% 21.680% 14.706% 39.457% 20.355% 44.343%ME 809 755 54 728,132 292,528 435,604 67.491% 68.212% 57.407% 79.568% 70.933% 85.366%MI 3,161 3,107 54 6,982,875 1,985,967 4,996,908 85.258% 85.356% 79.630% 97.294% 93.941% 98.626%MN 1,593 1,564 29 4,265,162 3,015,521 1,249,641 53.986% 54.668% 17.241% 45.926% 63.826% 2.733%MO 1,420 1,343 77 3,006,718 1,692,257 1,314,461 17.042% 14.669% 58.442% 38.284% 40.185% 35.836%MT 830 770 60 754,605 361,936 392,669 30.120% 28.571% 50.000% 60.882% 46.425% 74.206%NC 2,283 2,144 139 6,973,518 1,708,352 5,265,166 4.862% 4.571% 9.353% 14.120% 4.810% 17.141%ND 217 190 27 563,069 257,844 305,225 80.184% 81.579% 70.370% 81.725% 87.499% 76.847%NE 738 727 11 1,451,422 674,942 776,480 85.501% 85.695% 72.727% 95.398% 92.031% 98.325%NH 1,224 1,183 41 943,715 393,916 549,799 46.078% 47.168% 14.634% 32.036% 42.732% 24.373%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 15.066% 14.660% 29.730% 52.179% 26.331% 66.173%NM 724 685 39 1,667,433 1,400,885 266,548 84.392% 85.109% 71.795% 92.273% 97.015% 67.347%NV 338 317 21 973,480 283,589 689,891 81.657% 81.388% 85.714% 98.302% 94.487% 99.871%NY 1,579 1,339 240 11,205,386 1,225,943 9,979,443 9.373% 8.140% 16.250% 3.218% 6.757% 2.784%OH 1,929 1,804 125 10,221,998 3,127,061 7,094,937 25.713% 26.552% 13.600% 9.872% 18.497% 6.071%OK 208 176 32 771,000 278,233 492,767 31.250% 35.227% 9.375% 42.851% 46.323% 40.891%OR 1,105 952 153 2,941,297 575,817 2,365,480 40.724% 44.853% 15.033% 42.896% 56.243% 39.647%RI 143 134 9 913,584 173,606 739,978 2.098% 2.239% 0.000% 0.437% 2.301% 0.000%SC 595 542 53 3,127,334 572,473 2,554,861 0.840% 0.923% 0.000% 0.032% 0.172% 0.000%SD 189 181 8 280,317 205,756 74,561 41.270% 41.436% 37.500% 38.278% 49.407% 7.567%TN 351 162 189 5,685,258 1,462,502 4,222,756 12.251% 8.025% 15.873% 19.313% 4.883% 24.310%TX 4,912 4,570 342 25,069,082 9,284,197 15,784,885 35.464% 34.661% 46.199% 49.544% 41.222% 54.438%UT 507 457 50 2,543,652 1,686,017 857,635 79.487% 81.619% 60.000% 86.461% 93.091% 73.426%VA 1,582 1,414 168 4,803,590 634,524 4,169,066 6.384% 7.001% 1.190% 4.601% 17.881% 2.580%VT 601 557 44 493,135 226,967 266,168 17.304% 18.492% 2.273% 9.525% 20.484% 0.180%WI 1,826 1,806 20 4,044,712 2,352,968 1,691,744 40.854% 40.642% 60.000% 60.801% 45.697% 81.808%WV 465 304 161 1,434,609 253,819 1,180,790 8.602% 9.211% 7.453% 5.456% 16.889% 2.999%WY 304 255 49 446,184 129,168 317,016 17.763% 17.255% 20.408% 31.592% 20.595% 36.073%Total 49,473 45,387 4,086 230,393,228 85,737,044 144,656,184 37.329% 37.788% 32.232% 49.309% 50.451% 48.633%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A4c. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 17 15 2 2.769% 3.205% 1.370% 9,939 9,718 221 1.645% 4.205% 0.059%AL 1 1 0 0.284% 0.358% 0.000% 6,300 6,300 0 0.134% 0.431% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 43 41 2 4.068% 4.063% 4.167% 110,553 71,128 39,425 1.794% 2.547% 1.170%CA 76 65 11 1.969% 1.948% 2.099% 1,406,938 504,206 902,732 3.881% 3.757% 3.954%CO 3 3 0 0.361% 0.493% 0.000% 10,890 10,890 0 0.218% 2.053% 0.000%CT 1 1 0 0.085% 0.088% 0.000% 85 85 0 0.003% 0.022% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.075% 0.076% 0.000% 30 30 0 0.000% 0.000% 0.000%GA 1 1 0 0.063% 0.068% 0.000% 16,284 16,284 0 0.225% 1.206% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 7 7 0 0.671% 0.693% 0.000% 968 968 0 0.038% 0.068% 0.000%ID 9 8 1 0.966% 0.915% 1.724% 2,144 1,619 525 0.196% 0.193% 0.205%IL 9 9 0 0.717% 0.780% 0.000% 4,168 4,168 0 0.046% 0.144% 0.000%IN 4 4 0 0.246% 0.254% 0.000% 2,229 2,229 0 0.045% 0.085% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 8 6 2 1.166% 1.056% 1.695% 37,002 11,010 25,992 0.434% 0.639% 0.382%MD 3 3 0 0.291% 0.311% 0.000% 18,180 18,180 0 0.362% 1.778% 0.000%ME 15 15 0 1.854% 1.987% 0.000% 31,493 31,493 0 4.325% 10.766% 0.000%MI 47 47 0 1.487% 1.513% 0.000% 16,913 16,913 0 0.242% 0.852% 0.000%MN 4 4 0 0.251% 0.256% 0.000% 331 331 0 0.008% 0.011% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 6 5 1 0.723% 0.649% 1.667% 5,975 903 5,072 0.792% 0.249% 1.292%NC 1 1 0 0.044% 0.047% 0.000% 450 450 0 0.006% 0.026% 0.000%ND 2 2 0 0.922% 1.053% 0.000% 2,528 2,528 0 0.449% 0.980% 0.000%NE 1 1 0 0.136% 0.138% 0.000% 40 40 0 0.003% 0.006% 0.000%NH 36 36 0 2.941% 3.043% 0.000% 11,059 11,059 0 1.172% 2.807% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 11 10 1 1.519% 1.460% 2.564% 524,745 524,512 233 31.470% 37.441% 0.087%NV 27 25 2 7.988% 7.886% 9.524% 442,206 51,336 390,870 45.425% 18.102% 56.657%NY 3 3 0 0.190% 0.224% 0.000% 1,170 1,170 0 0.010% 0.095% 0.000%OH 8 7 1 0.415% 0.388% 0.800% 7,555 3,008 4,547 0.074% 0.096% 0.064%OK 3 2 1 1.442% 1.136% 3.125% 152,225 26,794 125,431 19.744% 9.630% 25.454%OR 3 3 0 0.271% 0.315% 0.000% 425 425 0 0.014% 0.074% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 2 2 0 0.336% 0.369% 0.000% 274 274 0 0.009% 0.048% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 10 10 0 0.204% 0.219% 0.000% 19,684 19,684 0 0.079% 0.212% 0.000%UT 7 6 1 1.381% 1.313% 2.000% 12,445 3,895 8,550 0.489% 0.231% 0.997%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 1 1 0 0.166% 0.180% 0.000% 260 260 0 0.053% 0.115% 0.000%WI 1 1 0 0.055% 0.055% 0.000% 360 360 0 0.009% 0.015% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 371 346 25 0.750% 0.762% 0.612% 2,855,848 1,352,250 1,503,598 1.240% 1.577% 1.039%

Percent of Population Served 

with At Least One Detection 

> 0.05 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.05 mg/L

Percent of Systems 

with At Least One Detection 

> 0.05 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.05 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A4d. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 46 43 3 7.492% 9.188% 2.055% 33,908 24,487 9,421 5.612% 10.596% 2.525%AL 1 1 0 0.284% 0.358% 0.000% 6,300 6,300 0 0.134% 0.431% 0.000%AR 1 1 0 0.221% 0.262% 0.000% 37 37 0 0.002% 0.004% 0.000%AZ 148 140 8 14.002% 13.875% 16.667% 1,426,798 613,024 813,774 23.150% 21.951% 24.143%CA 221 200 21 5.725% 5.995% 4.008% 7,128,594 1,688,881 5,439,713 19.664% 12.584% 23.827%CO 4 4 0 0.482% 0.657% 0.000% 11,167 11,167 0 0.224% 2.106% 0.000%CT 6 6 0 0.513% 0.531% 0.000% 1,086 1,086 0 0.040% 0.284% 0.000%DE 1 1 0 0.356% 0.360% 0.000% 1,591 1,591 0 0.234% 0.399% 0.000%FL 1 1 0 0.075% 0.076% 0.000% 30 30 0 0.000% 0.000% 0.000%GA 2 2 0 0.126% 0.135% 0.000% 16,315 16,315 0 0.225% 1.208% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 21 21 0 2.013% 2.079% 0.000% 8,412 8,412 0 0.331% 0.588% 0.000%ID 41 39 2 4.399% 4.462% 3.448% 45,912 45,247 665 4.200% 5.407% 0.259%IL 42 41 1 3.347% 3.553% 0.990% 145,069 46,046 99,023 1.596% 1.594% 1.597%IN 30 30 0 1.847% 1.905% 0.000% 8,213 8,213 0 0.165% 0.313% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 18 15 3 2.624% 2.641% 2.542% 51,970 22,238 29,732 0.609% 1.291% 0.437%MD 13 13 0 1.260% 1.349% 0.000% 25,707 25,707 0 0.512% 2.514% 0.000%ME 48 47 1 5.933% 6.225% 1.852% 37,833 36,770 1,063 5.196% 12.570% 0.244%MI 202 201 1 6.390% 6.469% 1.852% 172,188 162,913 9,275 2.466% 8.203% 0.186%MN 48 48 0 3.013% 3.069% 0.000% 20,201 20,201 0 0.474% 0.670% 0.000%MO 1 1 0 0.070% 0.074% 0.000% 1,212 1,212 0 0.040% 0.072% 0.000%MT 16 14 2 1.928% 1.818% 3.333% 9,277 4,005 5,272 1.229% 1.107% 1.343%NC 5 5 0 0.219% 0.233% 0.000% 7,419 7,419 0 0.106% 0.434% 0.000%ND 14 14 0 6.452% 7.368% 0.000% 13,219 13,219 0 2.348% 5.127% 0.000%NE 5 5 0 0.678% 0.688% 0.000% 3,866 3,866 0 0.266% 0.573% 0.000%NH 86 85 1 7.026% 7.185% 2.439% 61,367 43,367 18,000 6.503% 11.009% 3.274%NJ 3 3 0 0.218% 0.224% 0.000% 237 237 0 0.003% 0.009% 0.000%NM 36 35 1 4.972% 5.109% 2.564% 606,085 605,852 233 36.348% 43.248% 0.087%NV 64 61 3 18.935% 19.243% 14.286% 487,590 96,420 391,170 50.087% 34.000% 56.700%NY 8 8 0 0.507% 0.597% 0.000% 3,493 3,493 0 0.031% 0.285% 0.000%OH 25 24 1 1.296% 1.330% 0.800% 13,184 8,637 4,547 0.129% 0.276% 0.064%OK 6 5 1 2.885% 2.841% 3.125% 198,878 73,447 125,431 25.795% 26.398% 25.454%OR 17 17 0 1.538% 1.786% 0.000% 7,902 7,902 0 0.269% 1.372% 0.000%RI 1 1 0 0.699% 0.746% 0.000% 95 95 0 0.010% 0.055% 0.000%SC 2 2 0 0.336% 0.369% 0.000% 274 274 0 0.009% 0.048% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 3 1 2 0.855% 0.617% 1.058% 28,672 226 28,446 0.504% 0.015% 0.674%TX 45 44 1 0.916% 0.963% 0.292% 176,847 78,702 98,145 0.705% 0.848% 0.622%UT 21 19 2 4.142% 4.158% 4.000% 288,889 204,299 84,590 11.357% 12.117% 9.863%VA 1 1 0 0.063% 0.071% 0.000% 140 140 0 0.003% 0.022% 0.000%VT 4 4 0 0.666% 0.718% 0.000% 6,128 6,128 0 1.243% 2.700% 0.000%WI 8 8 0 0.438% 0.443% 0.000% 998 998 0 0.025% 0.042% 0.000%WV 1 1 0 0.215% 0.329% 0.000% 2,500 2,500 0 0.174% 0.985% 0.000%WY 5 4 1 1.645% 1.569% 2.041% 500 350 150 0.112% 0.271% 0.047%Total 1,271 1,216 55 2.569% 2.679% 1.346% 11,060,103 3,901,453 7,158,650 4.801% 4.550% 4.949%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A4e. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 107 99 8 17.427% 21.154% 5.479% 285,512 52,751 232,761 47.251% 22.827% 62.377%AL 4 4 0 1.136% 1.434% 0.000% 48,842 48,842 0 1.039% 3.338% 0.000%AR 3 3 0 0.662% 0.787% 0.000% 4,784 4,784 0 0.195% 0.526% 0.000%AZ 336 321 15 31.788% 31.814% 31.250% 4,799,509 1,810,409 2,989,100 77.873% 64.828% 88.682%CA 586 518 68 15.181% 15.528% 12.977% 13,280,982 3,272,066 10,008,916 36.636% 24.380% 43.841%CO 16 11 5 1.928% 1.806% 2.262% 31,795 19,558 12,237 0.636% 3.688% 0.274%CT 25 25 0 2.137% 2.210% 0.000% 4,339 4,339 0 0.160% 1.135% 0.000%DE 4 4 0 1.423% 1.439% 0.000% 4,442 4,442 0 0.653% 1.115% 0.000%FL 3 3 0 0.225% 0.229% 0.000% 880 880 0 0.005% 0.006% 0.000%GA 3 3 0 0.188% 0.203% 0.000% 16,343 16,343 0 0.226% 1.210% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 42 42 0 4.027% 4.158% 0.000% 26,647 26,647 0 1.049% 1.861% 0.000%ID 118 112 6 12.661% 12.815% 10.345% 399,686 193,554 206,132 36.564% 23.132% 80.407%IL 72 71 1 5.737% 6.153% 0.990% 224,068 125,045 99,023 2.466% 4.330% 1.597%IN 147 145 2 9.052% 9.206% 4.082% 151,633 77,736 73,897 3.045% 2.967% 3.131%KY 3 1 2 1.240% 1.075% 1.342% 56,804 8,461 48,343 1.234% 2.254% 1.144%MA 34 27 7 4.956% 4.754% 5.932% 136,331 47,745 88,586 1.598% 2.771% 1.301%MD 47 47 0 4.554% 4.876% 0.000% 83,479 83,479 0 1.663% 8.164% 0.000%ME 126 124 2 15.575% 16.424% 3.704% 73,901 71,600 2,301 10.149% 24.476% 0.528%MI 570 568 2 18.032% 18.281% 3.704% 745,619 438,990 306,629 10.678% 22.105% 6.136%MN 131 131 0 8.223% 8.376% 0.000% 248,365 248,365 0 5.823% 8.236% 0.000%MO 8 8 0 0.563% 0.596% 0.000% 11,164 11,164 0 0.371% 0.660% 0.000%MT 38 35 3 4.578% 4.545% 5.000% 20,653 8,857 11,796 2.737% 2.447% 3.004%NC 13 13 0 0.569% 0.606% 0.000% 21,285 21,285 0 0.305% 1.246% 0.000%ND 36 35 1 16.590% 18.421% 3.704% 33,565 29,049 4,516 5.961% 11.266% 1.480%NE 74 73 1 10.027% 10.041% 9.091% 57,170 56,777 393 3.939% 8.412% 0.051%NH 204 202 2 16.667% 17.075% 4.878% 116,064 87,064 29,000 12.299% 22.102% 5.275%NJ 31 30 1 2.256% 2.244% 2.703% 753,876 77,622 676,254 9.712% 2.847% 13.429%NM 89 87 2 12.293% 12.701% 5.128% 764,452 691,518 72,934 45.846% 49.363% 27.362%NV 127 123 4 37.574% 38.801% 19.048% 546,637 155,217 391,420 56.153% 54.733% 56.736%NY 24 22 2 1.520% 1.643% 0.833% 43,254 39,290 3,964 0.386% 3.205% 0.040%OH 159 157 2 8.243% 8.703% 1.600% 118,852 112,305 6,547 1.163% 3.591% 0.092%OK 13 11 2 6.250% 6.250% 6.250% 274,257 74,258 199,999 35.572% 26.689% 40.587%OR 64 62 2 5.792% 6.513% 1.307% 73,597 58,294 15,303 2.502% 10.124% 0.647%RI 1 1 0 0.699% 0.746% 0.000% 95 95 0 0.010% 0.055% 0.000%SC 3 3 0 0.504% 0.554% 0.000% 766 766 0 0.024% 0.134% 0.000%SD 11 11 0 5.820% 6.077% 0.000% 3,075 3,075 0 1.097% 1.494% 0.000%TN 5 1 4 1.425% 0.617% 2.116% 75,771 226 75,545 1.333% 0.015% 1.789%TX 82 81 1 1.669% 1.772% 0.292% 215,265 117,120 98,145 0.859% 1.261% 0.622%UT 60 57 3 11.834% 12.473% 6.000% 521,996 437,286 84,710 20.522% 25.936% 9.877%VA 12 12 0 0.759% 0.849% 0.000% 19,118 19,118 0 0.398% 3.013% 0.000%VT 8 8 0 1.331% 1.436% 0.000% 7,204 7,204 0 1.461% 3.174% 0.000%WI 60 60 0 3.286% 3.322% 0.000% 87,688 87,688 0 2.168% 3.727% 0.000%WV 6 5 1 1.290% 1.645% 0.621% 3,603 3,502 101 0.251% 1.380% 0.009%WY 11 8 3 3.618% 3.137% 6.122% 3,753 700 3,053 0.841% 0.542% 0.963%Total 3,516 3,364 152 7.107% 7.412% 3.720% 24,397,121 8,655,516 15,741,605 10.589% 10.095% 10.882%

Percent of Population Served 

with At Least One Detection 

> 0.01 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.01 mg/L

Percent of Systems 

with At Least One Detection 

> 0.01 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.01 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A4f. Arsenic – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 169 158 11 27.524% 33.761% 7.534% 355,254 121,657 233,597 58.793% 52.645% 62.601%AL 7 5 2 1.989% 1.792% 2.740% 118,793 51,242 67,551 2.527% 3.502% 2.086%AR 10 9 1 2.208% 2.362% 1.389% 37,187 14,573 22,614 1.516% 1.602% 1.466%AZ 638 613 25 60.360% 60.753% 52.083% 5,458,866 2,213,313 3,245,553 88.572% 79.256% 96.290%CA 1,141 1,009 132 29.560% 30.246% 25.191% 21,011,998 6,737,394 14,274,604 57.962% 50.200% 62.525%CO 62 49 13 7.470% 8.046% 5.882% 277,495 67,649 209,846 5.555% 12.756% 4.700%CT 48 48 0 4.103% 4.244% 0.000% 15,831 15,831 0 0.583% 4.141% 0.000%DE 13 12 1 4.626% 4.317% 33.333% 112,259 6,989 105,270 16.513% 1.754% 37.409%FL 81 80 1 6.067% 6.112% 3.846% 688,227 655,228 32,999 3.961% 4.331% 1.469%GA 23 23 0 1.444% 1.555% 0.000% 29,565 29,565 0 0.408% 2.190% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 103 102 1 9.875% 10.099% 3.030% 201,475 74,145 127,330 7.932% 5.179% 11.485%ID 317 310 7 34.013% 35.469% 12.069% 662,662 453,378 209,284 60.622% 54.183% 81.636%IL 138 134 4 10.996% 11.612% 3.960% 646,695 396,227 250,468 7.116% 13.720% 4.040%IN 323 319 4 19.889% 20.254% 8.163% 430,812 356,083 74,729 8.650% 13.591% 3.166%KY 33 12 21 13.636% 12.903% 14.094% 540,085 103,537 436,548 11.735% 27.576% 10.328%MA 76 67 9 11.079% 11.796% 7.627% 306,743 164,678 142,065 3.596% 9.558% 2.087%MD 131 130 1 12.694% 13.485% 1.471% 164,072 150,920 13,152 3.268% 14.759% 0.329%ME 279 275 4 34.487% 36.424% 7.407% 132,232 127,193 5,039 18.160% 43.481% 1.157%MI 1,036 1,033 3 32.774% 33.248% 5.556% 1,063,035 753,044 309,991 15.223% 37.918% 6.204%MN 270 270 0 16.949% 17.263% 0.000% 422,532 422,532 0 9.907% 14.012% 0.000%MO 30 27 3 2.113% 2.010% 3.896% 80,640 67,154 13,486 2.682% 3.968% 1.026%MT 105 93 12 12.651% 12.078% 20.000% 356,324 118,951 237,373 47.220% 32.865% 60.451%NC 81 74 7 3.548% 3.451% 5.036% 90,474 63,757 26,717 1.297% 3.732% 0.507%ND 62 58 4 28.571% 30.526% 14.815% 130,909 67,526 63,383 23.249% 26.189% 20.766%NE 361 356 5 48.916% 48.968% 45.455% 1,136,491 388,140 748,351 78.302% 57.507% 96.377%NH 314 312 2 25.654% 26.374% 4.878% 134,658 105,658 29,000 14.269% 26.822% 5.275%NJ 90 87 3 6.550% 6.507% 8.108% 1,469,207 261,936 1,207,271 18.927% 9.607% 23.973%NM 256 251 5 35.359% 36.642% 12.821% 1,135,771 1,059,785 75,986 68.115% 75.651% 28.507%NV 212 204 8 62.722% 64.353% 38.095% 883,230 230,098 653,132 90.729% 81.138% 94.672%NY 61 58 3 3.863% 4.332% 1.250% 71,120 51,513 19,607 0.635% 4.202% 0.196%OH 341 336 5 17.678% 18.625% 4.000% 263,944 244,539 19,405 2.582% 7.820% 0.274%OK 30 28 2 14.423% 15.909% 6.250% 299,712 99,713 199,999 38.873% 35.838% 40.587%OR 145 141 4 13.122% 14.811% 2.614% 219,995 179,332 40,663 7.480% 31.144% 1.719%RI 2 2 0 1.399% 1.493% 0.000% 295 295 0 0.032% 0.170% 0.000%SC 5 5 0 0.840% 0.923% 0.000% 986 986 0 0.032% 0.172% 0.000%SD 50 50 0 26.455% 27.624% 0.000% 36,580 36,580 0 13.050% 17.778% 0.000%TN 17 2 15 4.843% 1.235% 7.937% 661,668 1,908 659,760 11.638% 0.130% 15.624%TX 642 610 32 13.070% 13.348% 9.357% 5,906,433 1,397,937 4,508,496 23.561% 15.057% 28.562%UT 146 136 10 28.797% 29.759% 20.000% 1,173,073 603,257 569,816 46.118% 35.780% 66.440%VA 35 35 0 2.212% 2.475% 0.000% 47,931 47,931 0 0.998% 7.554% 0.000%VT 33 33 0 5.491% 5.925% 0.000% 22,931 22,931 0 4.650% 10.103% 0.000%WI 249 247 2 13.636% 13.677% 10.000% 602,490 464,972 137,518 14.896% 19.761% 8.129%WV 22 20 2 4.731% 6.579% 1.242% 11,472 9,570 1,902 0.800% 3.770% 0.161%WY 41 36 5 13.487% 14.118% 10.204% 42,455 24,430 18,025 9.515% 18.913% 5.686%Total 8,228 7,859 369 16.631% 17.316% 9.031% 47,454,607 18,464,077 28,990,530 20.597% 21.536% 20.041%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A5. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration or 

Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 7 MFL 6,873 11 0.160% 22,423,343 57,015 0.254%


 6,873 19 0.276% 22,423,343 82,927 0.370%

> 7 MFL 1,405 3 0.214% 62,738,591 196,962 0.314%


 1,405 6 0.427% 62,738,591 322,738 0.514%

> 7 MFL 8,278 14 0.169% 85,161,934 253,977 0.298%


 8,278 25 0.302% 85,161,934 405,665 0.476%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A5a. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 24 18 6 4.167% 0.000% 16.667% 1.33 1.33 1.33 1.33 1.33 1.33 1.33 1.33AL 2 1 1 0.000% 0.000% 0.000%ARAZ 2,264 1,927 337 0.442% 0.415% 0.593% 0.2 0.2 0.4 0.45 0.36 0.45 4.27 5.5 0.5 5.5 5.5 0.5CA 6,158 3,858 2,300 2.046% 1.918% 2.261% 0.02 0.02 0.02 0.375 0.55 0.2 3.38 4 1.07 79.08 79.08 14CO 7 5 2 28.571% 40.000% 0.000% 0.4 0.4 1.27 1.27 2.14 2.14 2.14 2.14CT 625 557 68 2.560% 1.975% 7.353% 0.1 0.1 0.12 0.17 0.17 0.19 1.15 0.72 6.3 6.3 1.15 6.3DE 2 0 2 0.000% 0.000% 0.000%FL 75 72 3 2.667% 2.778% 0.000% 0.16 0.16 0.175 0.175 0.19 0.19 0.19 0.19GA 10 10 0 0.000% 0.000% 0.000%HIIA 51 44 7 3.922% 4.545% 0.000% 0.2 0.2 0.695 0.695 1.19 1.19 1.19 1.19ID 128 106 22 6.250% 5.660% 9.091% 0.16 0.16 0.19 0.64 1.83 0.235 2.76 2.76 0.28 2.76 2.76 0.28IL 126 71 55 11.905% 4.225% 21.818% 0.008 0.03 0.008 0.08 0.03 0.1 0.25 0.07 0.25 1.72 0.07 1.72IN 152 131 21 1.974% 2.290% 0.000% 0.09 0.09 0.46 0.46 7 7 7 7KY 461 203 258 11.931% 24.138% 2.326% 0.1 0.1 0.1 0.61 0.92 0.19 5 5.2 0.51 143.9 143.9 0.51MA 201 111 90 2.985% 3.604% 2.222% 0.07 0.07 0.2 0.185 0.12 5.1 10 0.57 10 10 0.57 10MD 2 2 0 0.000% 0.000% 0.000%ME 27 19 8 3.704% 5.263% 0.000% 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2MIMNMOMT 296 248 48 1.351% 1.613% 0.000% 0.48 0.48 4.095 4.095 29 29 29 29NC 2,031 1,841 190 2.708% 2.173% 7.895% 0.17 0.17 0.17 0.17 0.17 0.18 0.52 0.36 0.71 29.3 29.3 0.87ND 17 8 9 0.000% 0.000% 0.000%NE 8 8 0 0.000% 0.000% 0.000%NH 2,929 2,765 164 0.000% 0.000% 0.000%NJ 383 290 93 13.316% 12.759% 15.054% 0.09 0.09 0.09 0.09 0.19 0.09 1.26 3.8 0.45 7.68 7.68 0.72NM 13 11 2 69.231% 81.818% 0.000% 0.17 0.17 0.17 0.17 0.19 0.19 0.19 0.19NV 266 202 64 0.752% 0.990% 0.000% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2NY 274 183 91 4.380% 2.732% 7.692% 0.14 0.14 0.15 0.2 0.18 0.2 0.34 10 0.2 10 10 0.2OH 629 492 137 2.067% 2.236% 1.460% 0.17 0.17 0.19 0.2 0.34 0.195 9.3 9.3 0.2 87.23 87.23 0.2OKOR 121 56 65 1.653% 0.000% 3.077% 0.2 0.2 0.27 0.27 0.34 0.34 0.34 0.34RI 23 13 10 0.000% 0.000% 0.000%SC 130 97 33 5.385% 6.186% 3.030% 0.17 0.17 0.17 0.19 0.97 0.17 5.63 5.63 0.17 5.63 5.63 0.17SD 39 36 3 0.000% 0.000% 0.000%TN 251 110 141 5.578% 6.364% 4.965% 0.01 0.07 0.01 0.48 0.36 6.4 317.2 3.2 2494 2494 3.2 2494TXUT 201 135 66 0.995% 1.481% 0.000% 0.36 0.36 0.445 0.445 0.53 0.53 0.53 0.53VA 2 0 2 0.000% 0.000% 0.000%VT 37 24 13 2.703% 4.167% 0.000% 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35WI 144 139 5 2.778% 2.878% 0.000% 0.03 0.03 0.155 0.155 1.54 1.54 1.54 1.54WV 15 15 0 86.667% 86.667% 0.000% 0.18 0.18 0.53 0.53 8.98 8.98 13.47 13.47WY 57 29 28 1.754% 0.000% 3.571% 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18Total 18,181 13,837 4,344 2.404% 2.211% 3.016% 0.008 0.02 0.008 0.2 0.26 0.2 3.48 4 1.07 2494 143.9 2494

Median Detect 

Concentration (MFL)

Maximum Detect 

Concentration (MFL)

90th Percentile Detect 

Concentration (MFL) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (MFL)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A5b. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 16 11 5 33,462 18,076 15,386 6.250% 0.000% 20.000% 6.873% 0.000% 14.949%AL 2 1 1 4,000 3,600 400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ARAZ 924 879 45 5,215,395 1,908,412 3,306,983 0.866% 0.796% 2.222% 30.358% 2.604% 46.374%CA 1,388 1,017 371 27,789,969 8,171,870 19,618,099 4.323% 3.147% 7.547% 23.732% 4.507% 31.740%CO 4 3 1 2,544 524 2,020 50.000% 66.667% 0.000% 15.566% 75.573% 0.000%CT 490 455 35 2,432,389 234,260 2,198,129 2.653% 1.978% 11.429% 7.669% 1.375% 8.340%DE 1 0 1 140,000 0 140,000 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 61 58 3 2,259,724 1,762,276 497,448 3.279% 3.448% 0.000% 0.156% 0.200% 0.000%GA 6 6 0 44,855 44,855 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 51 44 7 728,677 123,837 604,840 3.922% 4.545% 0.000% 0.863% 5.077% 0.000%ID 95 77 18 340,678 316,471 24,207 8.421% 7.792% 11.111% 28.788% 28.562% 31.739%IL 96 64 32 1,113,336 298,293 815,043 8.333% 4.688% 15.625% 17.835% 11.723% 20.072%IN 130 123 7 792,867 166,009 626,858 2.308% 2.439% 0.000% 0.050% 0.241% 0.000%KY 221 83 138 4,430,954 364,222 4,066,732 4.072% 3.614% 4.348% 2.702% 7.738% 2.251%MA 163 94 69 6,326,752 892,833 5,433,919 3.067% 3.191% 2.899% 0.984% 2.310% 0.766%MD 2 2 0 494 494 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ME 24 17 7 109,931 48,228 61,703 4.167% 5.882% 0.000% 1.569% 3.577% 0.000%MIMNMOMT 228 191 37 472,774 232,847 239,927 0.877% 1.047% 0.000% 15.673% 31.822% 0.000%NC 1,315 1,190 125 6,215,391 1,134,270 5,081,121 3.346% 2.689% 9.600% 24.529% 4.655% 28.966%ND 14 7 7 32,350 20,805 11,545 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 8 8 0 4,909 4,909 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,216 1,175 41 942,517 392,718 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 208 176 32 5,450,404 577,367 4,873,037 19.712% 17.614% 31.250% 24.894% 31.343% 24.130%NM 11 10 1 37,104 36,554 550 81.818% 90.000% 0.000% 96.658% 98.112% 0.000%NV 121 104 17 869,850 189,964 679,886 0.826% 0.962% 0.000% 0.667% 3.053% 0.000%NY 235 158 77 832,261 287,744 544,517 3.830% 3.165% 5.195% 4.002% 0.969% 5.605%OH 513 432 81 7,706,350 1,785,109 5,921,241 2.339% 2.315% 2.469% 22.364% 3.728% 27.983%OKOR 101 48 53 1,507,822 131,186 1,376,636 1.980% 0.000% 3.774% 3.018% 0.000% 3.305%RI 21 13 8 865,000 125,562 739,438 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 121 88 33 2,047,596 511,340 1,536,256 5.785% 6.818% 3.030% 1.395% 5.424% 0.054%SD 30 27 3 33,315 27,673 5,642 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 164 64 100 4,022,250 1,266,367 2,755,883 6.098% 9.375% 4.000% 5.045% 3.348% 5.824%TXUT 107 90 17 1,450,860 891,172 559,688 1.869% 2.222% 0.000% 1.103% 1.795% 0.000%VA 2 0 2 204 0 204 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 29 22 7 140,927 43,253 97,674 3.448% 4.545% 0.000% 0.106% 0.347% 0.000%WI 116 112 4 551,981 378,995 172,986 3.448% 3.571% 0.000% 0.603% 0.879% 0.000%WV 1 1 0 9,144 9,144 0 100.000% 100.000% 0.000% 100.000% 100.000% 0.000%WY 43 23 20 202,898 22,104 180,794 2.326% 0.000% 5.000% 1.018% 0.000% 1.142%Total 8,278 6,873 1,405 85,161,934 22,423,343 62,738,591 3.237% 2.663% 6.050% 16.345% 5.018% 20.393%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A5c. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ARAZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 4 3 1 0.288% 0.295% 0.270% 164,234 1,648 162,586 0.591% 0.020% 0.829%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 1 0 0.452% 1.205% 0.000% 15,222 15,222 0 0.344% 4.179% 0.000%MA 1 0 1 0.613% 0.000% 1.449% 33,600 0 33,600 0.531% 0.000% 0.618%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MIMNMOMT 1 1 0 0.439% 0.524% 0.000% 1,796 1,796 0 0.380% 0.771% 0.000%NC 2 2 0 0.152% 0.168% 0.000% 28,050 28,050 0 0.451% 2.473% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 1 1 0 0.481% 0.568% 0.000% 585 585 0 0.011% 0.101% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.426% 0.633% 0.000% 450 450 0 0.054% 0.156% 0.000%OH 1 1 0 0.195% 0.231% 0.000% 120 120 0 0.002% 0.007% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 0 1 0.610% 0.000% 1.000% 776 0 776 0.019% 0.000% 0.028%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 1 0 100.000% 100.000% 0.000% 9,144 9,144 0 100.000% 100.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 14 11 3 0.169% 0.160% 0.214% 253,977 57,015 196,962 0.298% 0.254% 0.314%

Percent of Population Served 

with At Least One Detection 

> 7 MFL

State

Number of Systems 

with At Least One Detection 

> 7 MFL

Percent of Systems 

with At Least One Detection 

> 7 MFL

Population Served by Systems 

with At Least One Detection 

> 7 MFL
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A5d. Asbestos – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ARAZ 1 1 0 0.108% 0.114% 0.000% 8,900 8,900 0 0.171% 0.466% 0.000%CA 6 4 2 0.432% 0.393% 0.539% 164,584 1,998 162,586 0.592% 0.024% 0.829%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 0 1 0.204% 0.000% 2.857% 51,128 0 51,128 2.102% 0.000% 2.326%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 1 1 0 0.769% 0.813% 0.000% 200 200 0 0.025% 0.120% 0.000%KY 1 1 0 0.452% 1.205% 0.000% 15,222 15,222 0 0.344% 4.179% 0.000%MA 1 0 1 0.613% 0.000% 1.449% 33,600 0 33,600 0.531% 0.000% 0.618%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MIMNMOMT 1 1 0 0.439% 0.524% 0.000% 1,796 1,796 0 0.380% 0.771% 0.000%NC 2 2 0 0.152% 0.168% 0.000% 28,050 28,050 0 0.451% 2.473% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 4 4 0 1.923% 2.273% 0.000% 4,897 4,897 0 0.090% 0.848% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.426% 0.633% 0.000% 450 450 0 0.054% 0.156% 0.000%OH 1 1 0 0.195% 0.231% 0.000% 120 120 0 0.002% 0.007% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 2 2 0 1.653% 2.273% 0.000% 12,150 12,150 0 0.593% 2.376% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 2 0 2 1.220% 0.000% 2.000% 75,424 0 75,424 1.875% 0.000% 2.737%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 1 0 100.000% 100.000% 0.000% 9,144 9,144 0 100.000% 100.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 25 19 6 0.302% 0.276% 0.427% 405,665 82,927 322,738 0.476% 0.370% 0.514%

Percent of Population Served 

with At Least One Detection 




State

Number of Systems 

with At Least One Detection 




Percent of Systems 

with At Least One Detection 




Population Served by Systems 

with At Least One Detection 



Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A6. Atrazine– Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 3 μg/L 33,752 7 0.021% 74,386,872 93,709 0.126%

	
 33,752 24 0.071% 74,386,872 220,526 0.296%

> 3 μg/L 3,463 91 2.628% 125,985,718 3,014,621 2.393%

	
 3,463 160 4.620% 125,985,718 7,977,093 6.332%

> 3 μg/L 37,215 98 0.263% 200,372,590 3,108,330 1.551%

	
 37,215 184 0.494% 200,372,590 8,197,619 4.091%

Surface Water

Combined Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A6a. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 52 17 35 0.000% 0.000% 0.000%AL 557 399 158 2.154% 0.251% 6.962% 0.09 0.1 0.09 0.19 0.1 0.19 0.29 0.1 0.29 1.1 0.1 1.1AR 1,657 1,411 246 0.241% 0.283% 0.000% 0.06 0.06 0.075 0.075 0.08 0.08 0.08 0.08AZ 6,990 5,427 1,563 0.100% 0.129% 0.000% 0.08 0.08 0.1 0.1 0.3 0.3 0.3 0.3CA 23,055 14,685 8,370 0.030% 0.041% 0.012% 0.16 0.16 1.4 1 0.91 1.4 2.6 2.6 1.4 2.6 2.6 1.4CO 2,499 1,824 675 1.080% 1.425% 0.148% 0.1 0.1 7.1 0.28 0.27 7.1 1 0.69 7.1 10 10 7.1CT 1,326 1,015 311 0.226% 0.296% 0.000% 0.2 0.2 0.22 0.22 0.22 0.22 0.22 0.22DE 1,266 1,221 45 1.422% 1.474% 0.000% 0.1 0.1 0.1 0.1 0.3 0.3 0.4 0.4FL 2,415 2,341 74 0.745% 0.598% 5.405% 0.01 0.01 0.12 0.01 0.01 0.18 0.21 0.08 0.24 0.24 0.13 0.24GA 1,477 1,396 81 0.068% 0.000% 1.235% 6 6 6 6 6 6 6 6HI 2,101 2,004 97 9.281% 9.431% 6.186% 0.01 0.01 0.11 0.13 0.13 0.14 0.66 0.67 0.2 1.25 1.25 0.2IA 2,194 1,821 373 17.320% 6.370% 70.777% 0.1 0.1 0.1 0.255 0.175 0.4 0.97 0.36 1 10.1 1.9 10.1ID 2,869 2,569 300 0.627% 0.506% 1.667% 0.1 0.1 0.19 0.24 0.21 0.54 0.54 0.3 0.55 0.55 0.35 0.55IL 5,265 3,999 1,266 5.337% 0.125% 21.801% 0.3 0.35 0.3 0.64 0.69 0.63 1.8 1 1.8 27 1 27IN 2,672 2,331 341 4.566% 0.129% 34.897% 0.01 0.2 0.01 0.6 0.3 0.6 2.1 0.76 2.5 11 0.76 11KY 1,949 436 1,513 10.159% 0.000% 13.087% 0.05 0.05 0.48 0.48 2.48 2.48 21 21MA 3,071 2,251 820 0.847% 0.666% 1.341% 0.06 0.1 0.06 0.1 0.2 0.1 0.3 0.3 0.2 0.3 0.3 0.24MD 2,931 1,809 1,122 5.937% 3.040% 10.606% 0.00037 0.01 0.00037 0.265 0.3 0.23 0.66 0.66 0.7 3.3 2.3 3.3ME 456 391 65 0.000% 0.000% 0.000%MI 6,924 6,424 500 0.534% 0.016% 7.200% 0.2 0.2 0.2 0.6 0.2 0.6 4 0.2 4 7 0.2 7MN 4,760 4,619 141 1.534% 1.364% 7.092% 0.1 0.1 0.3 0.4 0.5 0.4 1.5 1.5 0.55 1.8 1.8 0.6MO 9,519 5,075 4,444 9.024% 0.296% 18.992% 0.5 0.55 0.5 0.93 2.55 0.92 2.21 5.02 2.14 15 10.9 15MT 3,018 2,709 309 0.033% 0.037% 0.000% 1.41 1.41 1.41 1.41 1.41 1.41 1.41 1.41NC 13,265 12,111 1,154 0.528% 0.140% 4.593% 0.1 0.1 0.1 0.215 0.34 0.2 2.3 3.9 0.97 5.2 3.9 5.2ND 409 343 66 0.244% 0.000% 1.515% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1NE 4,480 4,131 349 26.473% 25.466% 38.395% 0.08 0.08 0.08 0.15 0.15 0.21 0.44 0.34 1.03 9.07 6 9.07NH 4,193 3,874 319 0.191% 0.207% 0.000% 0.2 0.2 0.345 0.345 0.6 0.6 0.6 0.6NJ 195 176 19 1.026% 0.568% 5.263% 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13NM 4,524 4,261 263 1.260% 1.338% 0.000% 0.23 0.23 0.78 0.78 1.55 1.55 3.71 3.71NV 1,595 1,163 432 0.063% 0.086% 0.000% 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09NY 2,937 2,198 739 0.238% 0.000% 0.947% 0.04 0.04 0.11 0.11 0.16 0.16 0.16 0.16OH 7,571 4,182 3,389 19.852% 0.526% 43.700% 0.1 0.1 0.1 0.6 0.305 0.6 2 1.4 2 27 2.2 27OKOR 2,062 1,577 485 0.097% 0.127% 0.000% 0.2 0.2 0.26 0.26 0.32 0.32 0.32 0.32RI 926 633 293 3.348% 3.791% 2.389% 0.1 0.1 0.12 0.12 0.11 0.14 0.23 0.13 0.48 0.48 0.23 0.48SC 2,906 2,516 390 0.000% 0.000% 0.000%SD 976 854 122 0.102% 0.000% 0.820% 1.61 1.61 1.61 1.61 1.61 1.61 1.61 1.61TN 1,021 94 927 4.897% 1.064% 5.286% 0.05 2.6 0.05 0.18 2.6 0.17 0.69 2.6 0.65 3.9 2.6 3.9TX 11,280 5,352 5,928 11.082% 3.120% 18.269% 0.1 0.1 0.1 0.36 0.3 0.37 0.92 0.91 0.92 9.01 2.2 9.01UT 7,103 5,915 1,188 0.014% 0.017% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1VA 503 178 325 0.398% 0.000% 0.615% 0.9 0.9 1.05 1.05 1.2 1.2 1.2 1.2VT 1,419 1,206 213 0.493% 0.166% 2.347% 0.06 0.06 0.06 0.2 0.13 0.21 0.44 0.2 0.44 0.44 0.2 0.44WI 3,353 3,260 93 5.488% 5.552% 3.226% 0.003 0.003 0.1 0.3 0.3 0.1 0.8 0.8 0.2 1.8 1.8 0.2WV 651 339 312 1.690% 1.475% 1.923% 0.07 0.07 0.07 0.1 0.33 0.1 0.5 0.56 0.5 0.56 0.56 0.5WY 1,298 978 320 0.000% 0.000% 0.000%Total 161,690 121,515 40,175 4.227% 1.725% 11.796% 0.00037 0.003 0.00037 0.4 0.19 0.55 1.43 0.69 1.7 27 10.9 27

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A6b. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 12 7 5 245,571 13,636 231,935 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 178 130 48 2,788,859 625,336 2,163,523 5.056% 0.769% 16.667% 7.855% 1.019% 9.831%AR 454 382 72 2,453,348 910,322 1,543,026 0.441% 0.524% 0.000% 0.637% 1.716% 0.000%AZ 934 886 48 6,077,627 2,707,036 3,370,591 0.642% 0.677% 0.000% 12.374% 27.781% 0.000%CA 2,399 2,025 374 34,964,717 13,050,587 21,914,130 0.208% 0.198% 0.267% 0.353% 0.761% 0.110%CO 801 582 219 4,988,574 521,665 4,466,909 0.999% 1.203% 0.457% 0.206% 1.679% 0.034%CT 656 619 37 2,588,757 261,490 2,327,267 0.305% 0.323% 0.000% 0.451% 4.463% 0.000%DE 247 244 3 647,226 365,826 281,400 2.024% 2.049% 0.000% 1.601% 2.832% 0.000%FL 1,317 1,295 22 16,794,353 14,552,348 2,242,005 0.759% 0.541% 13.636% 20.009% 20.829% 14.684%GA 294 280 14 974,583 282,561 692,022 0.340% 0.000% 7.143% 0.274% 0.000% 0.386%HI 112 100 12 1,305,882 1,251,254 54,628 16.071% 17.000% 8.333% 21.818% 22.732% 0.879%IA 1,056 1,023 33 2,543,237 1,434,611 1,108,626 6.818% 4.301% 84.848% 44.073% 13.090% 84.166%ID 916 860 56 1,090,602 834,803 255,799 0.983% 0.814% 3.571% 21.825% 6.158% 72.955%IL 1,371 1,267 104 9,186,700 2,986,303 6,200,397 4.887% 0.395% 59.615% 16.769% 0.609% 24.553%IN 1,411 1,366 45 4,875,411 2,552,675 2,322,736 1.843% 0.146% 53.333% 33.681% 2.680% 67.752%KY 242 93 149 4,602,489 375,460 4,227,029 17.355% 0.000% 28.188% 46.060% 0.000% 50.151%MA 644 527 117 8,485,298 1,682,916 6,802,382 1.242% 0.759% 3.419% 1.714% 1.810% 1.691%MD 862 794 68 4,906,096 907,989 3,998,107 3.364% 1.259% 27.941% 79.256% 1.466% 96.923%ME 269 241 28 510,420 134,500 375,920 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,934 2,873 61 7,227,105 2,047,249 5,179,856 0.239% 0.035% 9.836% 1.855% 0.001% 2.587%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 1.709% 1.431% 13.793% 15.066% 0.479% 46.405%MO 1,474 1,397 77 3,282,439 1,701,108 1,581,331 3.867% 0.358% 67.532% 13.913% 5.322% 23.154%MT 813 753 60 753,259 360,590 392,669 0.123% 0.133% 0.000% 0.011% 0.023% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 1.099% 0.314% 13.869% 11.023% 0.898% 14.430%ND 209 182 27 559,198 253,973 305,225 0.478% 0.000% 3.704% 16.526% 0.000% 30.277%NE 762 751 11 1,455,834 679,354 776,480 13.911% 13.316% 54.545% 67.864% 33.993% 97.498%NH 1,237 1,196 41 945,754 395,955 549,799 0.243% 0.251% 0.000% 0.669% 1.598% 0.000%NJ 131 119 12 2,002,039 354,819 1,647,220 1.527% 0.840% 8.333% 1.028% 0.166% 1.214%NM 695 659 36 1,661,712 1,398,814 262,898 1.007% 1.062% 0.000% 2.312% 2.746% 0.000%NV 295 274 21 961,667 271,776 689,891 0.339% 0.365% 0.000% 0.021% 0.074% 0.000%NY 1,345 1,114 231 4,925,284 982,007 3,943,277 0.297% 0.000% 1.732% 0.503% 0.000% 0.628%OH 1,939 1,814 125 10,227,103 3,132,166 7,094,937 4.693% 0.772% 61.600% 36.844% 2.892% 51.832%OKOR 1,085 935 150 2,938,854 574,104 2,364,750 0.184% 0.214% 0.000% 0.071% 0.361% 0.000%RI 105 97 8 902,560 163,122 739,438 4.762% 4.124% 12.500% 9.327% 9.758% 9.232%SC 770 711 59 3,427,270 800,487 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 261 240 21 622,272 263,101 359,171 0.383% 0.000% 4.762% 2.202% 0.000% 3.815%TN 210 39 171 5,082,009 967,746 4,114,263 13.333% 2.564% 15.789% 9.444% 0.009% 11.663%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 6.743% 1.982% 30.267% 49.956% 10.360% 64.424%UT 426 389 37 2,500,671 1,667,485 833,186 0.235% 0.257% 0.000% 4.239% 6.357% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.549% 0.000% 0.901% 4.391% 0.000% 4.448%VT 450 417 33 435,710 184,546 251,164 0.667% 0.480% 3.030% 1.394% 3.242% 0.036%WI 1,416 1,396 20 3,885,086 2,193,342 1,691,744 3.955% 3.797% 15.000% 4.962% 4.129% 6.043%WV 343 197 146 1,366,917 206,326 1,160,591 2.624% 2.538% 2.740% 7.929% 0.488% 9.252%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 37,215 33,752 3,463 200,372,590 74,386,872 125,985,718 2.386% 1.132% 14.612% 17.077% 7.923% 22.482%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A6c. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 2 1 1 0.250% 0.172% 0.457% 2,614 1,114 1,500 0.052% 0.214% 0.034%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.340% 0.000% 7.143% 2,671 0 2,671 0.274% 0.000% 0.386%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 1 0 1 0.095% 0.000% 3.030% 4,573 0 4,573 0.180% 0.000% 0.412%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 9 0 9 0.656% 0.000% 8.654% 113,232 0 113,232 1.233% 0.000% 1.826%IN 6 0 6 0.425% 0.000% 13.333% 53,737 0 53,737 1.102% 0.000% 2.314%KY 8 0 8 3.306% 0.000% 5.369% 114,484 0 114,484 2.487% 0.000% 2.708%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 0 1 0.116% 0.000% 1.471% 54,000 0 54,000 1.101% 0.000% 1.351%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 3 0 3 0.102% 0.000% 4.918% 26,843 0 26,843 0.371% 0.000% 0.518%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 25 3 22 1.696% 0.215% 28.571% 251,575 90,373 161,202 7.664% 5.313% 10.194%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 1 1 0.085% 0.045% 0.730% 50,598 150 50,448 0.735% 0.009% 0.979%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 1 1 0.262% 0.133% 9.091% 514,144 1,980 512,164 35.316% 0.291% 65.960%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 1 1 0 0.144% 0.152% 0.000% 92 92 0 0.006% 0.007% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 28 0 28 1.444% 0.000% 22.400% 1,680,358 0 1,680,358 16.430% 0.000% 23.684%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 0 1 0.476% 0.000% 0.585% 40,994 0 40,994 0.807% 0.000% 0.996%TX 8 0 8 0.400% 0.000% 2.374% 198,415 0 198,415 0.922% 0.000% 1.259%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 98 7 91 0.263% 0.021% 2.628% 3,108,330 93,709 3,014,621 1.551% 0.126% 2.393%

Percent of Population Served 

with At Least One Detection 

> 3 μg/L

State

Number of Systems 

with At Least One Detection 

> 3 μg/L

Percent of Systems 

with At Least One Detection 

> 3 μg/L

Population Served by Systems 

with At Least One Detection 

> 3 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A6d. Atrazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.042% 0.049% 0.000% 98,730 98,730 0 0.282% 0.757% 0.000%CO 2 1 1 0.250% 0.172% 0.457% 2,614 1,114 1,500 0.052% 0.214% 0.034%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.340% 0.000% 7.143% 2,671 0 2,671 0.274% 0.000% 0.386%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 6 2 4 0.568% 0.196% 12.121% 76,656 9,848 66,808 3.014% 0.686% 6.026%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 18 0 18 1.313% 0.000% 17.308% 331,755 0 331,755 3.611% 0.000% 5.351%IN 10 0 10 0.709% 0.000% 22.222% 1,148,282 0 1,148,282 23.553% 0.000% 49.437%KY 19 0 19 7.851% 0.000% 12.752% 408,419 0 408,419 8.874% 0.000% 9.662%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 4 2 2 0.464% 0.252% 2.941% 67,320 120 67,200 1.372% 0.013% 1.681%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 3 0 3 0.102% 0.000% 4.918% 26,843 0 26,843 0.371% 0.000% 0.518%MN 1 1 0 0.078% 0.079% 0.000% 40 40 0 0.001% 0.001% 0.000%MO 39 4 35 2.646% 0.286% 45.455% 317,810 90,478 227,332 9.682% 5.319% 14.376%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 1 1 0.085% 0.045% 0.730% 50,598 150 50,448 0.735% 0.009% 0.979%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 4 2 2 0.525% 0.266% 18.182% 522,701 2,198 520,503 35.904% 0.324% 67.034%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 3 3 0 0.432% 0.455% 0.000% 292 292 0 0.018% 0.021% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 44 1 43 2.269% 0.055% 34.400% 2,479,796 325 2,479,471 24.247% 0.010% 34.947%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 1 0 1 0.383% 0.000% 4.762% 13,703 0 13,703 2.202% 0.000% 3.815%TN 3 1 2 1.429% 2.564% 1.170% 48,881 85 48,796 0.962% 0.009% 1.186%TX 22 4 18 1.099% 0.240% 5.341% 2,597,519 14,157 2,583,362 12.068% 0.246% 16.388%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.071% 0.072% 0.000% 2,989 2,989 0 0.077% 0.136% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 184 24 160 0.494% 0.071% 4.620% 8,197,619 220,526 7,977,093 4.091% 0.296% 6.332%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A7. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 2 mg/L 45,118 61 0.135% 85,388,860 189,533 0.222%	
 45,118 225 0.499% 85,388,860 609,877 0.714%> 2 mg/L 4,007 5 0.125% 144,386,847 21,575 0.015%	
 4,007 15 0.374% 144,386,847 211,283 0.146%> 2 mg/L 49,125 66 0.134% 229,775,707 211,108 0.092%	
 49,125 240 0.489% 229,775,707 821,160 0.357%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A7a. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 871 619 252 76.464% 80.452% 66.667% 0.00044 0.001 0.00044 0.02 0.02 0.01 0.12 0.12 0.09 1.12 1.12 0.67AL 2,673 1,813 860 33.071% 26.806% 46.279% 0.00022 0.00064 0.00022 0.02 0.03 0.02 0.1 0.13 0.08 0.92 0.7 0.92AR 2,187 1,532 655 92.318% 93.538% 89.466% 0.0011 0.0016 0.0011 0.02 0.03 0.01 0.14 0.17 0.03 2.39 2.39 0.28AZ 6,315 4,935 1,380 82.470% 80.831% 88.333% 0.001 0.001 0.0011 0.05 0.05 0.05 0.17 0.19 0.11 1.92 1.92 1CA 35,330 20,859 14,471 32.205% 36.900% 25.437% 8.8E-05 8.8E-05 0.0001 0.11 0.1 0.11 0.21 0.21 0.22 8.6 8.6 1.2CO 4,391 2,334 2,057 87.543% 87.961% 87.069% 0.00081 0.00081 0.0009 0.04 0.05 0.03 0.15 0.17 0.1 0.83 0.83 0.68CT 2,589 1,866 723 63.963% 62.540% 67.635% 0.0007 0.0019 0.0007 0.03 0.03 0.02 0.21 0.23 0.2 2.16 2.16 0.51DE 693 645 48 65.801% 64.341% 85.417% 0.0002 0.0002 0.02 0.05 0.06 0.03 0.23 0.24 0.05 0.9 0.9 0.19FL 2,139 2,070 69 66.854% 66.618% 73.913% 0.0002 0.0002 0.0012 0.01 0.01 0.01 0.03 0.03 0.03 2 2 0.11GA 2,884 2,490 394 17.268% 19.679% 2.030% 0.01 0.01 0.05 0.07 0.07 0.05 0.2 0.2 0.1 0.44 0.44 0.1HI 1,166 1,104 62 5.232% 5.525% 0.000% 0.01 0.01 0.01 0.01 0.02 0.02 0.11 0.11IA 1,490 1,227 263 73.758% 76.039% 63.118% 0.01 0.01 0.01 0.1 0.12 0.07 0.34 0.37 0.11 1.67 1.67 0.85ID 2,661 2,388 273 46.749% 48.660% 30.037% 0.0005 0.0005 0.008 0.07 0.07 0.06 0.14 0.15 0.1 0.9 0.9 0.15IL 3,597 3,194 403 92.383% 91.703% 97.767% 0.0006 0.0006 0.002 0.06 0.07 0.02 0.4 0.5 0.06 7.44 7.44 1IN 4,811 4,330 481 80.815% 80.554% 83.160% 9.9E-05 9.9E-05 0.0012 0.07 0.08 0.02 0.32 0.34 0.1 5.81 5.81 0.89KY 1,788 552 1,236 85.011% 90.761% 82.443% 0.0004 0.003 0.0004 0.02 0.03 0.02 0.07 0.23 0.05 2.63 2.63 0.61MA 2,998 2,003 995 55.137% 50.474% 64.523% 0.001 0.001 0.001 0.01 0.02 0.01 0.09 0.12 0.06 2 2 2MD 5,108 3,988 1,120 37.529% 30.767% 61.607% 0.001 0.001 0.001 0.03 0.07 0.02 0.21 0.25 0.05 1.18 1.18 1.01ME 2,716 2,318 398 88.071% 86.281% 98.492% 0.0005 0.0005 0.0007 0.0052 0.006 0.0034 0.04 0.05 0.01 6.2 6.2 0.08MI 6,144 5,970 174 86.182% 85.829% 98.276% 0.001 0.001 0.004 0.06 0.07 0.02 0.21 0.21 0.03 3 3 0.1MN 3,337 3,288 49 67.276% 68.157% 8.163% 0.02 0.02 0.02 0.07 0.07 0.1 0.21 0.21 0.18 2.3 2.3 0.18MO 5,684 4,907 777 96.569% 96.026% 100.000% 0.00106 0.00106 0.00576 0.06 0.06 0.05 0.19 0.21 0.11 1.85 1.41 1.85MT 2,757 2,471 286 52.992% 55.807% 28.671% 0.002 0.002 0.005 0.11 0.12 0.07 0.3 0.3 0.2 0.9 0.9 0.5NC 9,225 7,786 1,439 25.192% 21.346% 46.004% 0.0008 0.0008 0.0046 0.02 0.03 0.01 0.12 0.14 0.02 1.3 1.3 0.87ND 346 303 43 97.399% 97.030% 100.000% 0.001 0.001 0.00482 0.03 0.03 0.01 0.12 0.14 0.05 0.56 0.56 0.05NE 1,884 1,798 86 97.081% 96.997% 98.837% 0.01 0.01 0.01 0.12 0.13 0.11 0.25 0.25 0.21 0.91 0.91 0.24NH 3,187 3,003 184 53.404% 52.714% 64.674% 0.0008 0.0008 0.003 0.01 0.01 0.01 0.07 0.08 0.01 0.78 0.78 0.03NJ 6,571 5,854 717 65.119% 63.153% 81.172% 0.001 0.001 0.002 0.05 0.05 0.04 0.25 0.27 0.16 2.9 2.9 0.8NM 3,514 3,188 326 62.379% 63.582% 50.613% 8.6E-05 8.6E-05 0.0062 0.06 0.06 0.03 0.2 0.2 0.2 1.27 1.27 0.84NV 1,994 1,454 540 88.365% 87.414% 90.926% 0.001 0.001 0.0028 0.05 0.05 0.04 0.11 0.11 0.12 0.85 0.85 0.19NY 3,711 2,817 894 64.188% 65.708% 59.396% 0.00028 0.00028 0.001 0.06 0.07 0.02 0.3 0.33 0.15 19 19 19OH 4,129 3,494 635 58.465% 57.928% 61.417% 0.00011 0.00011 0.0023 0.09 0.11 0.02 0.32 0.36 0.09 4.07 4.07 0.83OK 421 346 75 97.150% 97.399% 96.000% 0.00018 0.00018 0.01 0.12 0.13 0.1 0.38 0.39 0.29 1.5 1.5 0.98OR 1,317 956 361 41.686% 46.757% 28.255% 0.0002 0.0002 0.0003 0.0089 0.009 0.00745 0.04 0.04 0.04 11 0.6 11RI 891 661 230 31.538% 33.132% 26.957% 0.0019 0.0019 0.02 0.03 0.03 0.03 0.08 0.08 0.07 0.34 0.34 0.13SC 3,445 2,981 464 8.505% 9.124% 4.526% 0.02 0.04 0.02 0.07 0.07 0.06 0.14 0.14 0.07 0.52 0.52 0.08SD 388 359 29 88.918% 88.301% 96.552% 0.0009 0.0009 0.01 0.06 0.06 0.05 0.16 0.17 0.11 0.93 0.93 0.15TN 1,537 481 1,056 95.511% 92.723% 96.780% 0.00053 0.00053 0.0022 0.02 0.02 0.02 0.06 0.18 0.04 1.6 1.6 0.43TX 14,920 12,336 2,584 98.237% 98.038% 99.187% 0.0012 0.0012 0.0023 0.07 0.08 0.06 0.25 0.26 0.16 4.01 4.01 1.27UT 7,023 5,480 1,543 89.577% 87.792% 95.917% 0.007 0.007 0.01 0.06 0.06 0.05 0.18 0.17 0.18 1.1 1.1 0.58VA 2,820 2,210 610 8.759% 8.959% 8.033% 0.003 0.003 0.007 0.11 0.2 0.02 0.41 0.44 0.26 0.98 0.98 0.58VT 2,048 1,727 321 47.900% 52.056% 25.545% 0.001 0.001 0.002 0.03 0.03 0.02 0.1 0.1 0.03 0.52 0.52 0.2WI 7,152 6,981 171 91.415% 91.620% 83.041% 0.0001 0.0001 0.0019 0.03 0.03 0.01 0.12 0.12 0.02 16 16 0.19WV 1,135 444 691 34.626% 52.928% 22.865% 0.00019 0.00019 0.01 0.1 0.21 0.04 0.67 1.04 0.21 9.98 9.98 0.79WY 1,131 876 255 28.294% 31.050% 18.824% 0.0047 0.01 0.0047 0.13 0.13 0.1 0.3 0.3 0.26 0.8 0.8 0.32Total 183,118 142,438 40,680 60.955% 62.814% 54.444% 8.6E-05 8.6E-05 0.0001 0.05 0.06 0.04 0.21 0.23 0.15 19 19 19

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A7b. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 493 394 99 523,158 211,375 311,783 83.570% 86.802% 70.707% 90.002% 88.961% 90.708%AL 353 280 73 4,707,360 1,469,326 3,238,034 57.507% 50.714% 83.562% 79.110% 61.065% 87.298%AR 453 381 72 2,452,800 909,774 1,543,026 98.896% 98.688% 100.000% 99.937% 99.830% 100.000%AZ 1,049 1,001 48 6,161,306 2,790,715 3,370,591 91.802% 91.608% 95.833% 97.116% 94.126% 99.591%CA 3,826 3,302 524 36,246,208 13,416,333 22,829,875 49.582% 49.273% 51.527% 79.433% 79.837% 79.196%CO 838 617 221 4,998,506 533,275 4,465,231 96.539% 95.462% 99.548% 99.722% 97.464% 99.992%CT 1,169 1,130 39 2,716,117 382,195 2,333,922 68.178% 67.345% 92.308% 95.072% 75.700% 98.245%DE 279 276 3 679,635 398,235 281,400 73.118% 72.826% 100.000% 94.791% 91.111% 100.000%FL 1,331 1,305 26 17,209,555 14,963,513 2,246,042 68.670% 68.199% 92.308% 82.772% 83.927% 75.073%GA 1,600 1,485 115 7,244,380 1,352,049 5,892,331 20.938% 22.290% 3.478% 6.856% 28.945% 1.788%HI 107 95 12 1,303,767 1,249,139 54,628 11.215% 12.632% 0.000% 61.180% 63.855% 0.000%IA 967 934 33 2,500,395 1,391,769 1,108,626 74.767% 74.518% 81.818% 65.532% 76.332% 51.973%ID 896 849 47 1,049,622 806,747 242,875 63.616% 64.311% 51.064% 87.792% 85.799% 94.414%IL 1,490 1,387 103 9,168,134 2,968,062 6,200,072 95.503% 95.242% 99.029% 99.504% 98.491% 99.989%IN 1,623 1,574 49 4,980,057 2,619,602 2,360,455 87.246% 86.849% 100.000% 98.838% 97.792% 100.000%KY 242 93 149 4,602,489 375,460 4,227,029 96.281% 95.699% 96.644% 98.807% 98.330% 98.850%MA 675 557 118 8,525,485 1,718,061 6,807,424 65.185% 62.118% 79.661% 78.633% 37.850% 88.926%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 52.505% 50.515% 80.882% 95.702% 79.610% 99.825%ME 808 754 54 727,802 292,198 435,604 90.594% 89.920% 100.000% 98.426% 96.079% 100.000%MI 2,995 2,943 52 6,681,641 1,889,310 4,792,331 92.287% 92.219% 96.154% 99.031% 97.554% 99.613%MN 1,459 1,432 27 3,959,159 2,725,622 1,233,537 72.447% 73.673% 7.407% 62.589% 90.853% 0.136%MO 1,421 1,344 77 3,006,743 1,692,282 1,314,461 98.944% 98.884% 100.000% 99.877% 99.781% 100.000%MT 846 787 59 757,540 365,141 392,399 64.066% 65.438% 45.763% 55.034% 65.431% 45.359%NC 2,284 2,145 139 6,973,592 1,708,426 5,265,166 44.308% 41.538% 87.050% 80.190% 41.563% 92.723%ND 217 190 27 563,069 257,844 305,225 97.235% 96.842% 100.000% 99.805% 99.575% 100.000%NE 731 720 11 1,449,290 672,810 776,480 97.674% 97.639% 100.000% 99.431% 98.775% 100.000%NH 1,223 1,182 41 943,800 394,001 549,799 68.765% 68.443% 78.049% 88.122% 78.255% 95.194%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 75.255% 74.720% 94.595% 93.090% 83.502% 98.281%NM 725 686 39 1,668,123 1,401,575 266,548 75.034% 75.364% 69.231% 85.981% 89.584% 67.037%NV 330 309 21 971,701 281,810 689,891 96.970% 96.764% 100.000% 99.828% 99.406% 100.000%NY 1,677 1,434 243 11,262,435 1,278,087 9,984,348 75.552% 74.616% 81.070% 32.586% 63.247% 28.661%OH 1,917 1,792 125 10,218,949 3,124,012 7,094,937 68.388% 67.243% 84.800% 64.356% 72.733% 60.668%OK 203 175 28 753,964 276,712 477,252 96.059% 96.571% 92.857% 99.143% 98.703% 99.397%OR 731 610 121 2,770,064 486,818 2,283,246 46.238% 48.361% 35.537% 45.684% 41.751% 46.522%RI 143 134 9 913,584 173,606 739,978 37.762% 37.313% 44.444% 37.139% 61.623% 31.395%SC 823 758 65 3,468,333 809,806 2,658,527 13.973% 14.644% 6.154% 7.161% 19.151% 3.509%SD 235 224 11 328,972 237,011 91,961 94.894% 95.089% 90.909% 95.733% 97.489% 91.206%TN 350 161 189 5,683,572 1,460,816 4,222,756 97.429% 95.652% 98.942% 99.201% 99.335% 99.155%TX 4,930 4,587 343 25,070,435 9,285,450 15,784,985 98.803% 98.736% 99.708% 99.940% 99.839% 99.999%UT 507 457 50 2,543,652 1,686,017 857,635 92.308% 92.560% 90.000% 98.908% 99.095% 98.540%VA 1,586 1,418 168 4,805,368 636,302 4,169,066 10.530% 10.437% 11.310% 38.808% 9.608% 43.265%VT 598 556 42 490,389 226,621 263,768 66.388% 66.367% 66.667% 65.269% 74.956% 56.946%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 95.721% 95.729% 95.000% 97.240% 99.371% 94.277%WV 456 295 161 1,419,045 238,255 1,180,790 52.632% 56.949% 44.720% 51.933% 43.275% 53.680%WY 304 255 49 446,184 129,168 317,016 41.776% 42.745% 36.735% 58.615% 50.362% 61.978%Total 49,125 45,118 4,007 229,775,707 85,388,860 144,386,847 72.020% 71.978% 72.498% 79.473% 82.897% 77.449%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A7c. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 1 1 0 0.221% 0.262% 0.000% 275 275 0 0.011% 0.030% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 4 4 0 0.105% 0.121% 0.000% 76,100 76,100 0 0.210% 0.567% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.086% 0.088% 0.000% 34 34 0 0.001% 0.009% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 11 11 0 0.738% 0.793% 0.000% 92,301 92,301 0 1.007% 3.110% 0.000%IN 2 2 0 0.123% 0.127% 0.000% 1,107 1,107 0 0.022% 0.042% 0.000%KY 2 2 0 0.826% 2.151% 0.000% 510 510 0 0.011% 0.136% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 1 1 0 0.124% 0.133% 0.000% 53 53 0 0.007% 0.018% 0.000%MI 5 5 0 0.167% 0.170% 0.000% 2,934 2,934 0 0.044% 0.155% 0.000%MN 1 1 0 0.069% 0.070% 0.000% 1,066 1,066 0 0.027% 0.039% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 2 2 0 0.146% 0.150% 0.000% 223 223 0 0.003% 0.008% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 22 18 4 1.312% 1.255% 1.646% 12,354 6,659 5,695 0.110% 0.521% 0.057%OH 1 1 0 0.052% 0.056% 0.000% 110 110 0 0.001% 0.004% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 1 0 1 0.137% 0.000% 0.826% 15,880 0 15,880 0.573% 0.000% 0.696%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 2 2 0 0.041% 0.044% 0.000% 1,010 1,010 0 0.004% 0.011% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 8 8 0 0.439% 0.444% 0.000% 6,251 6,251 0 0.155% 0.266% 0.000%WV 2 2 0 0.439% 0.678% 0.000% 900 900 0 0.063% 0.378% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 66 61 5 0.134% 0.135% 0.125% 211,108 189,533 21,575 0.092% 0.222% 0.015%

Percent of Population Served 

with At Least One Detection 

> 2 mg/L

State

Number of Systems 

with At Least One Detection 

> 2 mg/L

Percent of Systems 

with At Least One Detection 

> 2 mg/L

Population Served by Systems 

with At Least One Detection 

> 2 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A7d. Barium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.203% 0.254% 0.000% 302 302 0 0.058% 0.143% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 1 1 0 0.221% 0.262% 0.000% 275 275 0 0.011% 0.030% 0.000%AZ 10 7 3 0.953% 0.699% 6.250% 23,235 19,983 3,252 0.377% 0.716% 0.096%CA 15 14 1 0.392% 0.424% 0.191% 112,655 112,224 431 0.311% 0.836% 0.002%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 17 17 0 1.454% 1.504% 0.000% 1,547 1,547 0 0.057% 0.405% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 3 3 0 0.225% 0.230% 0.000% 41,411 41,411 0 0.241% 0.277% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 6 6 0 0.620% 0.642% 0.000% 3,379 3,379 0 0.135% 0.243% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 41 40 1 2.752% 2.884% 0.971% 334,996 233,018 101,978 3.654% 7.851% 1.645%IN 8 8 0 0.493% 0.508% 0.000% 34,846 34,846 0 0.700% 1.330% 0.000%KY 5 5 0 2.066% 5.376% 0.000% 3,232 3,232 0 0.070% 0.861% 0.000%MA 4 3 1 0.593% 0.539% 0.847% 56,825 40,825 16,000 0.667% 2.376% 0.235%MD 3 2 1 0.289% 0.206% 1.471% 5,190 90 5,100 0.103% 0.009% 0.128%ME 2 2 0 0.248% 0.265% 0.000% 1,921 1,921 0 0.264% 0.657% 0.000%MI 10 10 0 0.334% 0.340% 0.000% 3,285 3,285 0 0.049% 0.174% 0.000%MN 2 2 0 0.137% 0.140% 0.000% 4,782 4,782 0 0.121% 0.175% 0.000%MO 3 2 1 0.211% 0.149% 1.299% 2,395 653 1,742 0.080% 0.039% 0.133%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 2 0 0.088% 0.093% 0.000% 90 90 0 0.001% 0.005% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 13 13 0 0.946% 0.972% 0.000% 28,200 28,200 0 0.363% 1.034% 0.000%NM 1 1 0 0.138% 0.146% 0.000% 60 60 0 0.004% 0.004% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 36 31 5 2.147% 2.162% 2.058% 44,304 38,459 5,845 0.393% 3.009% 0.059%OH 11 11 0 0.574% 0.614% 0.000% 5,639 5,639 0 0.055% 0.181% 0.000%OK 2 2 0 0.985% 1.143% 0.000% 67 67 0 0.009% 0.024% 0.000%OR 1 0 1 0.137% 0.000% 0.826% 15,880 0 15,880 0.573% 0.000% 0.696%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 2 2 0 0.571% 1.242% 0.000% 165 165 0 0.003% 0.011% 0.000%TX 8 7 1 0.162% 0.153% 0.292% 63,910 2,855 61,055 0.255% 0.031% 0.387%UT 2 2 0 0.394% 0.438% 0.000% 15,870 15,870 0 0.624% 0.941% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 15 15 0 0.823% 0.832% 0.000% 10,022 10,022 0 0.248% 0.426% 0.000%WV 16 16 0 3.509% 5.424% 0.000% 6,677 6,677 0 0.471% 2.802% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 240 225 15 0.489% 0.499% 0.374% 821,160 609,877 211,283 0.357% 0.714% 0.146%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A8. Benzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 46,177 57 0.123% 86,395,538 338,086 0.391%

	
 46,177 100 0.217% 86,395,538 700,772 0.811%

	
 46,177 206 0.446% 86,395,538 1,079,744 1.250%

> 0.5 μg/L 46,177 283 0.613% 86,395,538 1,486,410 1.720%

> 5 μg/L 4,258 6 0.141% 140,551,755 148,852 0.106%

	
 4,258 10 0.235% 140,551,755 183,093 0.130%

	
 4,258 22 0.517% 140,551,755 4,038,337 2.873%

> 0.5 μg/L 4,258 39 0.916% 140,551,755 7,433,993 5.289%

> 5 μg/L 50,435 63 0.125% 226,947,293 486,938 0.215%

	
 50,435 110 0.218% 226,947,293 883,865 0.389%

	
 50,435 228 0.452% 226,947,293 5,118,081 2.255%

> 0.5 μg/L 50,435 322 0.638% 226,947,293 8,920,403 3.931%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A8a. Benzene – Summary Statistics of Any Detections by State and Source Water Type (Single detections are not MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,385 2,221 1,164 2.363% 2.792% 1.546% 0.15 0.21 0.15 0.66 0.66 0.615 3.095 2.14 4.14 16.1 16.1 11AL 845 617 228 4.024% 4.862% 1.754% 0.52 0.52 0.61 1.525 1.76 0.68 6.79 6.795 1.09 6.9 6.9 1.09AR 2,394 1,926 468 0.292% 0.312% 0.214% 0.32 0.32 0.73 1.02 1.325 0.73 2.96 2.96 0.73 2.96 2.96 0.73AZ 11,705 9,530 2,175 0.051% 0.031% 0.138% 0.5 0.53 0.5 0.515 1.5 0.5 5.3 5.3 0.5 5.3 5.3 0.5CA 86,914 46,232 40,682 0.351% 0.645% 0.017% 0.35 0.35 0.6 2.5 2.6 1 25.2 25.3 10 50 50 10CO 2,896 2,147 749 0.138% 0.186% 0.000% 0.11 0.11 0.12 0.12 0.5 0.5 0.5 0.5CT 6,945 6,053 892 0.216% 0.248% 0.000% 0.52 0.52 1.67 1.67 6.6 6.6 13 13DE 1,050 1,020 30 0.667% 0.686% 0.000% 0.78 0.78 1.03 1.03 1.48 1.48 1.48 1.48FL 4,178 4,110 68 0.957% 0.949% 1.471% 0.12 0.12 0.31 0.455 0.46 0.31 1.1 1.1 0.31 1.8 1.8 0.31GA 7,175 6,348 827 0.613% 0.551% 1.088% 0.55 0.55 0.68 1.85 2.1 1.7 3.9 4.1 2.1 11 11 2.1HI 1,791 1,688 103 0.000% 0.000% 0.000%IA 1,859 1,733 126 0.484% 0.519% 0.000% 0.5 0.5 1 1 3.2 3.2 3.2 3.2ID 3,739 3,278 461 0.027% 0.031% 0.000% 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6IL 7,011 6,450 561 0.328% 0.341% 0.178% 0.52 0.52 2.4 2.4 2.07 2.4 7.4 7.4 2.4 8.2 8.2 2.4IN 4,622 4,312 310 0.043% 0.046% 0.000% 0.6 0.6 1.95 1.95 3.3 3.3 3.3 3.3KY 3,309 1,126 2,183 0.181% 0.000% 0.275% 0.05 0.05 0.5 0.5 1 1 1 1MA 16,249 12,259 3,990 0.295% 0.302% 0.276% 0.4 0.4 0.5 0.81 0.8 1.23 1.7 1.4 3.28 11 3.7 11MD 6,773 5,511 1,262 1.152% 1.397% 0.079% 0.1 0.3 0.1 2.95 3 0.1 10 10 0.1 59.9 59.9 0.1ME 3,702 3,383 319 0.459% 0.355% 1.567% 0.5 0.5 0.5 0.9 1.4 0.8 12.3 12.3 0.9 15 15 0.9MI 10,755 9,745 1,010 0.158% 0.174% 0.000% 0.5 0.5 1 1 41.8 41.8 49.3 49.3MN 8,604 7,338 1,266 1.116% 0.940% 2.133% 0.05 0.05 0.2 0.45 0.4 0.8 2.4 2.3 2.5 5.9 5.9 2.8MO 7,543 6,694 849 0.491% 0.553% 0.000% 0.6 0.6 1.6 1.6 4.55 4.55 12.4 12.4MT 4,483 3,949 534 0.112% 0.127% 0.000% 1 1 3 3 3.9 3.9 3.9 3.9NC 19,062 17,483 1,579 0.362% 0.389% 0.063% 0.5 0.5 3.88 0.8 0.8 3.88 3.4 2.8 3.88 93 93 3.88ND 560 425 135 3.036% 4.000% 0.000% 0.51 0.51 0.9 0.9 4.79 4.79 9.13 9.13NE 6,843 6,265 578 0.205% 0.223% 0.000% 0.14 0.14 1.2 1.2 40 40 70 70NH 9,588 9,110 478 0.574% 0.604% 0.000% 0.5 0.5 1.1 1.1 4.1 4.1 13 13NJ 20,354 18,569 1,785 0.526% 0.560% 0.168% 0.12 0.12 0.5 0.7 0.795 0.7 4.98 4.98 0.7 28 28 0.7NM 6,573 6,097 476 0.974% 1.033% 0.210% 0.1 0.1 0.6 1.2 1.2 0.6 5 5 0.6 11.95 11.95 0.6NV 3,208 2,576 632 0.156% 0.194% 0.000% 0.5 0.5 0.5 0.5 1 1 1 1NY 7,134 5,455 1,679 0.196% 0.202% 0.179% 0.5 0.5 0.5 0.72 1.1 0.5 4.1 4.1 0.9 11.9 11.9 0.9OH 8,846 7,683 1,163 0.102% 0.104% 0.086% 0.5 0.5 0.5 0.68 0.795 0.5 1.5 1.5 0.5 1.5 1.5 0.5OK 5,355 3,958 1,397 0.224% 0.303% 0.000% 0.1 0.1 1.6 1.6 9.1 9.1 11.2 11.2OR 2,324 1,682 642 0.000% 0.000% 0.000%RI 1,958 1,590 368 0.715% 0.881% 0.000% 0.5 0.5 0.6 0.6 1.1 1.1 1.3 1.3SC 4,340 3,801 539 0.253% 0.184% 0.742% 0.72 0.72 3.23 3.23 1.4 5.33 7.43 4.94 8.56 8.56 4.94 8.56SD 889 855 34 0.225% 0.234% 0.000% 0.58 0.58 1.09 1.09 1.6 1.6 1.6 1.6TN 2,944 1,165 1,779 0.510% 1.202% 0.056% 0.53 0.53 0.74 0.77 0.785 0.74 1.2 1.2 0.74 1.5 1.5 0.74TX 34,152 27,047 7,105 0.524% 0.640% 0.084% 0.5 0.5 0.6 1.4 1.5 0.6 4 4 0.69 27 27 0.69UT 8,994 7,563 1,431 0.011% 0.013% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5VA 4,929 4,056 873 0.487% 0.542% 0.229% 0.5 0.5 1 1.05 1 11.5 7 4.4 22 22 18 22VT 4,359 3,965 394 0.138% 0.151% 0.000% 0.2 0.2 1.5 1.5 12.7 12.7 12.7 12.7WI 11,306 11,181 125 0.893% 0.885% 1.600% 0.03 0.03 0.13 0.58 0.6 0.185 4.8 5.55 0.24 11.6 11.6 0.24WV 1,196 500 696 3.094% 6.200% 0.862% 0.1 0.1 0.4 1 1.2 0.5 6.6 4.97 11.4 11.4 7.3 11.4WY 1,662 1,159 503 0.120% 0.173% 0.000% 0.65 0.65 3.025 3.025 5.4 5.4 5.4 5.4Total 374,503 289,855 84,648 0.438% 0.523% 0.146% 0.03 0.03 0.05 1.1 1.2 0.7 7.8 8 3.19 93 93 22

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A8b. Benzene – Summary of Stage 1 (Peak) Analyses of Any Detection > MRL (Single detections > MRL are not MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 3.226% 1.899% 7.534% 9.883% 23.492% 1.410%AL 264 202 62 4,228,835 1,123,190 3,105,645 3.788% 3.465% 4.839% 5.315% 15.334% 1.692%AR 454 382 72 2,453,348 910,322 1,543,026 1.322% 1.309% 1.389% 3.133% 0.626% 4.612%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.283% 0.198% 2.083% 4.899% 0.076% 8.901%CA 3,656 3,139 517 35,828,629 13,516,168 22,312,461 0.629% 0.605% 0.774% 1.253% 0.880% 1.480%CO 827 606 221 4,998,841 531,207 4,467,634 0.484% 0.660% 0.000% 0.021% 0.195% 0.000%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.497% 0.514% 0.000% 0.070% 0.490% 0.000%DE 318 315 3 698,987 417,587 281,400 0.629% 0.635% 0.000% 0.223% 0.374% 0.000%FL 1,511 1,485 26 17,497,814 15,251,772 2,246,042 0.927% 0.875% 3.846% 2.783% 1.605% 10.780%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.329% 0.293% 0.862% 0.173% 0.251% 0.152%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.758% 0.782% 0.000% 0.328% 0.582% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.107% 0.114% 0.000% 3.292% 4.298% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.560% 0.528% 0.962% 0.414% 0.900% 0.177%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.136% 0.140% 0.000% 0.054% 0.102% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 2.490% 0.000% 4.027% 8.996% 0.000% 9.795%MA 718 600 118 8,557,325 1,749,901 6,807,424 2.786% 2.000% 6.780% 44.243% 3.901% 54.614%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 1.139% 1.116% 1.471% 34.538% 2.437% 42.770%ME 810 757 53 728,347 292,773 435,574 1.358% 1.321% 1.887% 19.073% 0.675% 31.440%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.202% 0.206% 0.000% 0.864% 3.128% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 1.960% 1.933% 3.333% 4.649% 6.220% 0.862%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.353% 0.373% 0.000% 0.479% 0.852% 0.000%MT 848 788 60 757,949 365,280 392,669 0.354% 0.381% 0.000% 0.171% 0.354% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.634% 0.628% 0.719% 0.765% 1.815% 0.420%ND 210 183 27 562,397 257,172 305,225 2.381% 2.732% 0.000% 1.836% 4.015% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.908% 0.921% 0.000% 3.309% 7.057% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 1.590% 1.643% 0.000% 1.045% 2.486% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 2.718% 2.719% 2.703% 4.127% 10.202% 0.854%NM 726 687 39 1,698,755 1,432,207 266,548 1.791% 1.747% 2.564% 8.778% 5.336% 27.275%NV 338 317 21 973,592 283,701 689,891 0.592% 0.631% 0.000% 1.927% 6.613% 0.000%NY 1,524 1,288 236 4,894,938 1,044,336 3,850,602 0.722% 0.621% 1.271% 0.185% 0.826% 0.011%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.360% 0.330% 0.800% 0.041% 0.052% 0.037%OK 718 506 212 3,119,686 660,832 2,458,854 0.975% 1.383% 0.000% 0.286% 1.352% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 145 136 9 913,884 173,906 739,978 2.069% 2.206% 0.000% 0.597% 3.137% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.855% 0.793% 1.613% 0.414% 0.485% 0.394%SD 245 233 12 266,416 194,218 72,198 0.408% 0.429% 0.000% 0.250% 0.343% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 1.140% 1.852% 0.529% 1.908% 7.024% 0.136%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.727% 0.738% 0.585% 11.742% 1.219% 17.928%UT 500 454 46 2,553,197 1,698,877 854,320 0.200% 0.220% 0.000% 0.001% 0.002% 0.000%VA 1,599 1,428 171 5,273,208 630,625 4,642,583 0.625% 0.560% 1.170% 1.260% 0.460% 1.368%VT 603 560 43 491,035 227,067 263,968 0.663% 0.714% 0.000% 0.333% 0.720% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 1.570% 1.474% 10.000% 8.106% 12.425% 2.113%WV 403 243 160 1,416,020 237,670 1,178,350 4.467% 5.350% 3.125% 2.413% 1.243% 2.649%WY 304 256 48 446,177 129,229 316,948 0.658% 0.781% 0.000% 0.162% 0.561% 0.000%Total 50,435 46,177 4,258 226,947,293 86,395,538 140,551,755 0.884% 0.836% 1.409% 5.372% 2.382% 7.210%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A8c. Benzene – Summary of Stage 1 (Peak) Analyses of Any Detections > 5 μg/L (Single detections > 5 μg/L are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 2 1 1 0.323% 0.211% 0.685% 5,225 5,000 225 0.862% 2.150% 0.060%AL 2 2 0 0.758% 0.990% 0.000% 94,149 94,149 0 2.226% 8.382% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 125 125 0 0.002% 0.004% 0.000%CA 4 3 1 0.109% 0.096% 0.193% 118,343 13,011 105,332 0.330% 0.096% 0.472%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 65 65 0 0.002% 0.017% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 2,500 2,500 0 0.033% 0.157% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 3 3 0 0.210% 0.226% 0.000% 26,169 26,169 0 0.284% 0.867% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 1 0 1 0.139% 0.000% 0.847% 10,433 0 10,433 0.122% 0.000% 0.153%MD 5 5 0 0.474% 0.507% 0.000% 14,155 14,155 0 0.282% 1.381% 0.000%ME 3 3 0 0.370% 0.396% 0.000% 355 355 0 0.049% 0.121% 0.000%MI 1 1 0 0.034% 0.034% 0.000% 70 70 0 0.001% 0.004% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 2,287 2,287 0 0.054% 0.076% 0.000%MO 1 1 0 0.071% 0.075% 0.000% 75 75 0 0.002% 0.004% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 2 0 0.084% 0.090% 0.000% 115 115 0 0.002% 0.007% 0.000%ND 1 1 0 0.476% 0.546% 0.000% 2,614 2,614 0 0.465% 1.016% 0.000%NE 2 2 0 0.259% 0.263% 0.000% 40,511 40,511 0 2.771% 5.908% 0.000%NH 3 3 0 0.238% 0.247% 0.000% 1,948 1,948 0 0.205% 0.488% 0.000%NJ 3 3 0 0.215% 0.220% 0.000% 33,122 33,122 0 0.427% 1.221% 0.000%NM 3 3 0 0.413% 0.437% 0.000% 59,800 59,800 0 3.520% 4.175% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.161% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 1 1 0 0.139% 0.198% 0.000% 167 167 0 0.005% 0.025% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 0 1 0.122% 0.000% 1.613% 10,350 0 10,350 0.308% 0.000% 0.394%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 8 8 0 0.162% 0.174% 0.000% 37,062 37,062 0 0.148% 0.399% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 3 2 1 0.188% 0.140% 0.585% 203 153 50 0.004% 0.024% 0.001%VT 1 1 0 0.166% 0.179% 0.000% 116 116 0 0.024% 0.051% 0.000%WI 4 4 0 0.224% 0.227% 0.000% 1,832 1,832 0 0.045% 0.078% 0.000%WV 2 1 1 0.496% 0.412% 0.625% 22,837 375 22,462 1.613% 0.158% 1.906%WY 1 1 0 0.329% 0.391% 0.000% 625 625 0 0.140% 0.484% 0.000%Total 63 57 6 0.125% 0.123% 0.141% 486,938 338,086 148,852 0.215% 0.391% 0.106%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A8d. Benzene – Summary of Stage 1 (Peak) Analyses of Any Detections 	
	
!!"
#$

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 5 3 2 0.806% 0.633% 1.370% 6,826 6,250 576 1.126% 2.687% 0.154%AL 3 3 0 1.136% 1.485% 0.000% 94,474 94,474 0 2.234% 8.411% 0.000%AR 2 2 0 0.441% 0.524% 0.000% 113 113 0 0.005% 0.012% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 125 125 0 0.002% 0.004% 0.000%CA 6 5 1 0.164% 0.159% 0.193% 142,643 37,311 105,332 0.398% 0.276% 0.472%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 3 3 0 0.249% 0.257% 0.000% 1,707 1,707 0 0.063% 0.438% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 3 3 0 0.165% 0.176% 0.000% 2,828 2,828 0 0.038% 0.178% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 1 1 0 0.095% 0.098% 0.000% 834 834 0 0.033% 0.058% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 3 3 0 0.210% 0.226% 0.000% 26,169 26,169 0 0.284% 0.867% 0.000%IN 1 1 0 0.068% 0.070% 0.000% 130 130 0 0.003% 0.005% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 3 1 2 0.418% 0.167% 1.695% 11,483 50 11,433 0.134% 0.003% 0.168%MD 8 8 0 0.759% 0.811% 0.000% 18,470 18,470 0 0.368% 1.801% 0.000%ME 3 3 0 0.370% 0.396% 0.000% 355 355 0 0.049% 0.121% 0.000%MI 1 1 0 0.034% 0.034% 0.000% 70 70 0 0.001% 0.004% 0.000%MN 5 4 1 0.316% 0.258% 3.333% 22,376 11,598 10,778 0.525% 0.385% 0.862%MO 2 2 0 0.141% 0.149% 0.000% 12,575 12,575 0 0.419% 0.744% 0.000%MT 2 2 0 0.236% 0.254% 0.000% 794 794 0 0.105% 0.217% 0.000%NC 5 4 1 0.211% 0.180% 0.719% 22,539 427 22,112 0.322% 0.025% 0.420%ND 1 1 0 0.476% 0.546% 0.000% 2,614 2,614 0 0.465% 1.016% 0.000%NE 3 3 0 0.389% 0.395% 0.000% 40,698 40,698 0 2.783% 5.935% 0.000%NH 4 4 0 0.318% 0.329% 0.000% 2,418 2,418 0 0.255% 0.606% 0.000%NJ 4 4 0 0.286% 0.294% 0.000% 59,267 59,267 0 0.765% 2.185% 0.000%NM 5 5 0 0.689% 0.728% 0.000% 61,198 61,198 0 3.603% 4.273% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 3 3 0 0.197% 0.233% 0.000% 5,685 5,685 0 0.116% 0.544% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 2 2 0 0.279% 0.395% 0.000% 410 410 0 0.013% 0.062% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 3 2 1 0.366% 0.264% 1.613% 13,252 2,902 10,350 0.395% 0.396% 0.394%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 12 12 0 0.242% 0.260% 0.000% 48,564 48,564 0 0.193% 0.522% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 4 3 1 0.250% 0.210% 0.585% 685 635 50 0.013% 0.101% 0.001%VT 1 1 0 0.166% 0.179% 0.000% 116 116 0 0.024% 0.051% 0.000%WI 7 7 0 0.392% 0.397% 0.000% 260,825 260,825 0 6.457% 11.109% 0.000%WV 3 2 1 0.744% 0.823% 0.625% 22,997 535 22,462 1.624% 0.225% 1.906%WY 1 1 0 0.329% 0.391% 0.000% 625 625 0 0.140% 0.484% 0.000%Total 110 100 10 0.218% 0.217% 0.235% 883,865 700,772 183,093 0.389% 0.811% 0.130%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A8e. Benzene – Summary of Stage 1 (Peak) Analyses of Any Detections 	
	
!!"
#$

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 8 5 3 1.290% 1.055% 2.055% 54,859 53,850 1,009 9.050% 23.152% 0.270%AL 6 5 1 2.273% 2.475% 1.613% 160,231 139,177 21,054 3.789% 12.391% 0.678%AR 4 4 0 0.881% 1.047% 0.000% 751 751 0 0.031% 0.082% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 125 125 0 0.002% 0.004% 0.000%CA 14 12 2 0.383% 0.382% 0.387% 253,212 82,880 170,332 0.707% 0.613% 0.763%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 5 5 0 0.414% 0.428% 0.000% 1,777 1,777 0 0.065% 0.456% 0.000%DE 1 1 0 0.314% 0.317% 0.000% 60 60 0 0.009% 0.014% 0.000%FL 2 2 0 0.132% 0.135% 0.000% 68,298 68,298 0 0.390% 0.448% 0.000%GA 5 4 1 0.274% 0.234% 0.862% 12,531 3,561 8,970 0.167% 0.224% 0.152%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 4 4 0 0.379% 0.391% 0.000% 5,302 5,302 0 0.208% 0.370% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 5 4 1 0.350% 0.302% 0.962% 37,294 26,319 10,975 0.405% 0.872% 0.177%IN 1 1 0 0.068% 0.070% 0.000% 130 130 0 0.003% 0.005% 0.000%KY 1 0 1 0.415% 0.000% 0.671% 48,800 0 48,800 1.060% 0.000% 1.154%MA 12 6 6 1.671% 1.000% 5.085% 3,662,923 16,750 3,646,173 42.805% 0.957% 53.562%MD 9 9 0 0.854% 0.913% 0.000% 24,532 24,532 0 0.488% 2.393% 0.000%ME 7 7 0 0.864% 0.925% 0.000% 1,685 1,685 0 0.231% 0.576% 0.000%MI 3 3 0 0.101% 0.103% 0.000% 387 387 0 0.005% 0.020% 0.000%MN 8 7 1 0.506% 0.451% 3.333% 26,092 15,314 10,778 0.612% 0.509% 0.862%MO 4 4 0 0.282% 0.299% 0.000% 13,927 13,927 0 0.464% 0.824% 0.000%MT 3 3 0 0.354% 0.381% 0.000% 1,294 1,294 0 0.171% 0.354% 0.000%NC 14 13 1 0.591% 0.583% 0.719% 53,474 31,362 22,112 0.764% 1.810% 0.420%ND 2 2 0 0.952% 1.093% 0.000% 3,935 3,935 0 0.700% 1.530% 0.000%NE 5 5 0 0.649% 0.658% 0.000% 41,566 41,566 0 2.843% 6.062% 0.000%NH 9 9 0 0.715% 0.740% 0.000% 7,160 7,160 0 0.755% 1.795% 0.000%NJ 10 10 0 0.715% 0.735% 0.000% 80,941 80,941 0 1.045% 2.984% 0.000%NM 7 7 0 0.964% 1.019% 0.000% 63,553 63,553 0 3.741% 4.437% 0.000%NV 1 1 0 0.296% 0.315% 0.000% 18,000 18,000 0 1.849% 6.345% 0.000%NY 4 4 0 0.262% 0.311% 0.000% 5,779 5,779 0 0.118% 0.553% 0.000%OH 2 2 0 0.103% 0.110% 0.000% 355 355 0 0.003% 0.011% 0.000%OK 5 5 0 0.696% 0.988% 0.000% 7,101 7,101 0 0.228% 1.075% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 2 2 0 1.379% 1.471% 0.000% 1,955 1,955 0 0.214% 1.124% 0.000%SC 7 6 1 0.855% 0.793% 1.613% 13,904 3,554 10,350 0.414% 0.485% 0.394%SD 1 1 0 0.408% 0.429% 0.000% 666 666 0 0.250% 0.343% 0.000%TN 2 2 0 0.570% 1.235% 0.000% 19,604 19,604 0 0.345% 1.340% 0.000%TX 26 26 0 0.525% 0.564% 0.000% 67,358 67,358 0 0.268% 0.724% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 9 7 2 0.563% 0.490% 1.170% 65,421 1,899 63,522 1.241% 0.301% 1.368%VT 3 3 0 0.498% 0.536% 0.000% 1,286 1,286 0 0.262% 0.566% 0.000%WI 11 11 0 0.617% 0.624% 0.000% 266,391 266,391 0 6.595% 11.346% 0.000%WV 4 2 2 0.993% 0.823% 1.250% 24,797 535 24,262 1.751% 0.225% 2.059%WY 1 1 0 0.329% 0.391% 0.000% 625 625 0 0.140% 0.484% 0.000%Total 228 206 22 0.452% 0.446% 0.517% 5,118,081 1,079,744 4,038,337 2.255% 1.250% 2.873%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A8f. Benzene – Summary of Stage 1 (Peak) Analyses of Any Detections > 0.5 μg/L (Single detections > 0.5 μg/L are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 14 7 7 2.258% 1.477% 4.795% 57,112 54,300 2,812 9.421% 23.346% 0.753%AL 10 7 3 3.788% 3.465% 4.839% 224,778 172,233 52,545 5.315% 15.334% 1.692%AR 5 4 1 1.101% 1.047% 1.389% 71,912 751 71,161 2.931% 0.082% 4.612%AZ 2 2 0 0.189% 0.198% 0.000% 2,125 2,125 0 0.034% 0.076% 0.000%CA 21 17 4 0.574% 0.542% 0.774% 448,960 118,825 330,135 1.253% 0.879% 1.480%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 6 6 0 0.497% 0.514% 0.000% 1,907 1,907 0 0.070% 0.490% 0.000%DE 2 2 0 0.629% 0.635% 0.000% 1,560 1,560 0 0.223% 0.374% 0.000%FL 7 7 0 0.463% 0.471% 0.000% 111,025 111,025 0 0.635% 0.728% 0.000%GA 6 5 1 0.329% 0.293% 0.862% 12,968 3,998 8,970 0.173% 0.251% 0.152%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 7 7 0 0.663% 0.684% 0.000% 7,756 7,756 0 0.305% 0.541% 0.000%ID 1 1 0 0.107% 0.114% 0.000% 36,000 36,000 0 3.292% 4.298% 0.000%IL 8 7 1 0.560% 0.528% 0.962% 38,122 27,147 10,975 0.414% 0.900% 0.177%IN 2 2 0 0.136% 0.140% 0.000% 2,630 2,630 0 0.054% 0.102% 0.000%KY 1 0 1 0.415% 0.000% 0.671% 48,800 0 48,800 1.060% 0.000% 1.154%MA 18 11 7 2.507% 1.833% 5.932% 3,736,850 53,062 3,683,788 43.668% 3.032% 54.114%MD 10 10 0 0.949% 1.014% 0.000% 24,642 24,642 0 0.491% 2.403% 0.000%ME 9 8 1 1.111% 1.057% 1.887% 138,655 1,710 136,945 19.037% 0.584% 31.440%MI 5 5 0 0.168% 0.172% 0.000% 7,667 7,667 0 0.107% 0.388% 0.000%MN 12 11 1 0.759% 0.709% 3.333% 28,052 17,274 10,778 0.658% 0.574% 0.862%MO 5 5 0 0.353% 0.373% 0.000% 14,392 14,392 0 0.479% 0.852% 0.000%MT 3 3 0 0.354% 0.381% 0.000% 1,294 1,294 0 0.171% 0.354% 0.000%NC 15 14 1 0.634% 0.628% 0.719% 53,559 31,447 22,112 0.765% 1.815% 0.420%ND 5 5 0 2.381% 2.732% 0.000% 10,325 10,325 0 1.836% 4.015% 0.000%NE 6 6 0 0.778% 0.789% 0.000% 41,899 41,899 0 2.866% 6.110% 0.000%NH 16 16 0 1.272% 1.315% 0.000% 9,161 9,161 0 0.966% 2.296% 0.000%NJ 19 18 1 1.359% 1.323% 2.703% 181,576 138,576 43,000 2.343% 5.109% 0.854%NM 10 9 1 1.377% 1.310% 2.564% 138,554 65,853 72,701 8.156% 4.598% 27.275%NV 1 1 0 0.296% 0.315% 0.000% 18,000 18,000 0 1.849% 6.345% 0.000%NY 5 4 1 0.328% 0.311% 0.424% 5,897 5,779 118 0.120% 0.553% 0.003%OH 4 4 0 0.206% 0.220% 0.000% 639 639 0 0.006% 0.020% 0.000%OK 5 5 0 0.696% 0.988% 0.000% 7,101 7,101 0 0.228% 1.075% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 3 3 0 2.069% 2.206% 0.000% 5,455 5,455 0 0.597% 3.137% 0.000%SC 7 6 1 0.855% 0.793% 1.613% 13,904 3,554 10,350 0.414% 0.485% 0.394%SD 1 1 0 0.408% 0.429% 0.000% 666 666 0 0.250% 0.343% 0.000%TN 4 3 1 1.140% 1.852% 0.529% 108,469 102,719 5,750 1.908% 7.024% 0.136%TX 33 31 2 0.667% 0.673% 0.585% 2,940,114 104,845 2,835,269 11.708% 1.128% 17.928%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 9 7 2 0.563% 0.490% 1.170% 65,421 1,899 63,522 1.241% 0.301% 1.368%VT 3 3 0 0.498% 0.536% 0.000% 1,286 1,286 0 0.262% 0.566% 0.000%WI 16 16 0 0.897% 0.907% 0.000% 275,648 275,648 0 6.824% 11.741% 0.000%WV 4 2 2 0.993% 0.823% 1.250% 24,797 535 24,262 1.751% 0.225% 2.059%WY 2 2 0 0.658% 0.781% 0.000% 725 725 0 0.162% 0.561% 0.000%Total 322 283 39 0.638% 0.613% 0.916% 8,920,403 1,486,410 7,433,993 3.931% 1.720% 5.289%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A9. Benzo[a]pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.2 μg/L 25,566 9 0.035% 65,074,173 12,087 0.019%	
 25,566 35 0.137% 65,074,173 69,321 0.107%> 0.2 μg/L 3,012 5 0.166% 119,069,990 202,896 0.170%	
 3,012 18 0.598% 119,069,990 2,899,838 2.435%

> 0.2 μg/L 28,578 14 0.049% 184,144,163 214,983 0.117%	
 28,578 53 0.185% 184,144,163 2,969,159 1.612%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A9a. Benzo[a]pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 56 18 38 0.000% 0.000% 0.000%AL 606 432 174 0.165% 0.000% 0.575% 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14AR 2,242 1,924 318 0.089% 0.104% 0.000% 0.14 0.14 0.185 0.185 0.23 0.23 0.23 0.23AZ 7,083 5,514 1,569 0.184% 0.236% 0.000% 0.02 0.02 0.07 0.07 0.1 0.1 1 1CA 12,762 7,201 5,561 0.024% 0.042% 0.000% 0.01 0.01 0.02 0.02 0.02 0.02 0.02 0.02CO 2,518 1,826 692 0.119% 0.164% 0.000% 0.22 0.22 0.45 0.45 0.91 0.91 0.91 0.91CT 1,316 1,006 310 0.456% 0.497% 0.323% 0.04 0.04 0.04 0.04 0.04 0.04 0.09 0.09 0.04 0.09 0.09 0.04DE 1,084 1,054 30 0.092% 0.000% 3.333% 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09FL 2,409 2,342 67 0.457% 0.470% 0.000% 0.01 0.01 0.01 0.01 0.02 0.02 0.07 0.07GA 1,477 1,396 81 0.135% 0.000% 2.469% 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4HIIA 1,721 1,592 129 0.116% 0.126% 0.000% 0.01 0.01 0.015 0.015 0.02 0.02 0.02 0.02ID 2,237 1,958 279 0.000% 0.000% 0.000%IL 3,838 3,101 737 0.938% 0.871% 1.221% 0.02 0.02 0.02 0.03 0.03 0.02 0.06 0.06 0.09 0.09 0.06 0.09IN 2,294 2,099 195 0.044% 0.048% 0.000% 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07KY 2,368 632 1,736 0.465% 0.158% 0.576% 0.02 0.1 0.02 0.1 0.1 0.1 0.2 0.1 0.27 0.34 0.1 0.34MA 3,024 2,229 795 0.198% 0.135% 0.377% 0.02 0.02 0.02 0.03 0.04 0.02 0.44 0.44 0.1 0.44 0.44 0.1MD 2,806 1,727 1,079 0.570% 0.579% 0.556% 0.01 0.1 0.01 0.1 0.1 0.06 0.14 0.1 0.18 0.18 0.1 0.18ME 290 253 37 0.000% 0.000% 0.000%MI 309 181 128 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 324 194 130 0.000% 0.000% 0.000%MT 2,992 2,694 298 0.067% 0.037% 0.336% 0.15 0.15 0.2 0.175 0.15 0.2 0.2 0.15 0.2 0.2 0.15 0.2NC 13,168 12,083 1,085 0.076% 0.066% 0.184% 0.02 0.02 0.03 0.07 0.07 0.11 0.22 0.25 0.19 0.25 0.25 0.19ND 51 26 25 0.000% 0.000% 0.000%NE 4,480 4,131 349 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.048% 0.052% 0.000% 0.1 0.1 0.18 0.18 0.26 0.26 0.26 0.26NJ 41 33 8 0.000% 0.000% 0.000%NM 4,568 4,303 265 0.066% 0.023% 0.755% 0.18 0.18 0.54 0.54 0.18 0.54 0.54 0.18 0.54 0.54 0.18 0.54NV 1,615 1,180 435 0.124% 0.000% 0.460% 0.03 0.03 0.045 0.045 0.06 0.06 0.06 0.06NY 2,782 2,068 714 0.036% 0.048% 0.000% 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19OH 897 648 249 0.111% 0.000% 0.402% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02OKOR 2,067 1,583 484 0.048% 0.063% 0.000% 0.007 0.007 0.007 0.007 0.007 0.007 0.007 0.007RI 916 623 293 1.310% 0.482% 3.072% 0.11 0.13 0.11 0.15 0.15 0.15 0.18 0.18 0.25 0.25 0.18 0.25SC 3,061 2,687 374 0.033% 0.037% 0.000% 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07SD 956 847 109 0.000% 0.000% 0.000%TN 86 30 56 0.000% 0.000% 0.000%TX 10,269 4,527 5,742 0.000% 0.000% 0.000%UT 7,089 5,911 1,178 0.000% 0.000% 0.000%VA 488 177 311 0.820% 2.260% 0.000% 0.1 0.1 0.15 0.15 0.4 0.4 0.4 0.4VT 1,324 1,122 202 0.302% 0.357% 0.000% 0.01 0.01 0.01 0.01 0.1 0.1 0.1 0.1WI 1,392 1,337 55 0.072% 0.075% 0.000% 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03WV 633 328 305 1.896% 2.134% 1.639% 0.02 0.09 0.02 0.09 0.09 0.09 0.2 0.12 0.5 0.5 0.12 0.5WY 1,278 962 316 0.000% 0.000% 0.000%Total 119,871 92,473 27,398 0.142% 0.124% 0.201% 0.007 0.007 0.01 0.07 0.06 0.1 0.2 0.18 0.34 1 1 0.54

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A9b. Benzo[a]pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 12 7 5 245,571 13,636 231,935 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 181 134 47 3,561,828 783,747 2,778,081 0.552% 0.000% 2.128% 6.899% 0.000% 8.845%AR 454 382 72 2,453,348 910,322 1,543,026 0.441% 0.524% 0.000% 0.160% 0.431% 0.000%AZ 932 884 48 6,077,394 2,706,803 3,370,591 1.180% 1.244% 0.000% 1.141% 2.563% 0.000%CA 1,248 1,003 245 33,260,784 11,815,880 21,444,904 0.160% 0.199% 0.000% 0.005% 0.015% 0.000%CO 798 580 218 4,983,378 519,459 4,463,919 0.376% 0.517% 0.000% 0.026% 0.252% 0.000%CT 651 614 37 2,588,823 261,556 2,327,267 0.922% 0.814% 2.703% 1.569% 1.743% 1.550%DE 231 228 3 632,320 350,920 281,400 0.433% 0.000% 33.333% 22.141% 0.000% 49.751%FL 1,325 1,304 21 16,797,224 14,555,604 2,241,620 0.453% 0.460% 0.000% 15.786% 18.217% 0.000%GA 294 280 14 974,583 282,561 692,022 0.340% 0.000% 7.143% 0.274% 0.000% 0.386%HIIA 1,056 1,023 33 2,543,237 1,434,611 1,108,626 0.189% 0.196% 0.000% 1.045% 1.853% 0.000%ID 852 798 54 1,067,176 820,768 246,408 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,082 984 98 9,085,023 2,890,945 6,194,078 3.050% 2.541% 8.163% 3.144% 3.677% 2.896%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.071% 0.074% 0.000% 0.002% 0.003% 0.000%KY 242 93 149 4,602,489 375,460 4,227,029 3.719% 1.075% 5.369% 29.029% 0.557% 31.558%MA 642 525 117 8,482,868 1,680,486 6,802,382 0.779% 0.571% 1.709% 2.450% 0.017% 3.052%MD 862 794 68 4,906,096 907,989 3,998,107 1.624% 1.259% 5.882% 72.257% 0.801% 88.485%ME 179 155 24 482,407 112,465 369,942 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 89 62 27 5,100,237 379,121 4,721,116 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 226 157 69 928,947 284,141 644,806 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.246% 0.133% 1.667% 4.176% 0.083% 7.934%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.423% 0.359% 1.460% 6.376% 0.262% 8.433%ND 12 6 6 25,377 18,348 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.162% 0.167% 0.000% 0.827% 1.976% 0.000%NJ 36 30 6 1,444,605 143,223 1,301,382 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 694 658 36 1,661,547 1,398,649 262,898 0.288% 0.152% 2.778% 4.381% 0.007% 27.654%NV 294 273 21 961,367 271,476 689,891 0.680% 0.000% 9.524% 1.456% 0.000% 2.029%NY 1,264 1,043 221 4,879,789 946,878 3,932,911 0.079% 0.096% 0.000% 0.082% 0.422% 0.000%OH 310 233 77 6,600,708 622,035 5,978,673 0.323% 0.000% 1.299% 0.727% 0.000% 0.803%OKOR 1,088 938 150 2,937,559 572,809 2,364,750 0.092% 0.107% 0.000% 0.022% 0.113% 0.000%RI 105 97 8 902,560 163,122 739,438 2.857% 1.031% 25.000% 13.226% 0.067% 16.129%SC 782 723 59 3,439,550 812,767 2,626,783 0.128% 0.138% 0.000% 0.006% 0.027% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 15 6 9 1,439,720 848,945 590,775 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 1,883 1,546 337 21,494,935 5,731,435 15,763,500 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,671 1,667,485 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 178 69 109 2,179,119 28,420 2,150,699 1.685% 4.348% 0.000% 0.084% 6.464% 0.000%VT 443 410 33 433,067 181,903 251,164 0.903% 0.976% 0.000% 0.824% 1.962% 0.000%WI 922 903 19 3,201,690 1,581,206 1,620,484 0.108% 0.111% 0.000% 0.001% 0.003% 0.000%WV 339 195 144 1,358,655 205,557 1,153,098 2.950% 3.590% 2.083% 0.791% 0.672% 0.812%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 28,578 25,566 3,012 184,144,163 65,074,173 119,069,990 0.490% 0.399% 1.262% 5.057% 4.456% 5.385%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A9c. Benzo[a]pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 1 1 0 0.220% 0.262% 0.000% 1,964 1,964 0 0.080% 0.216% 0.000%AZ 1 1 0 0.107% 0.113% 0.000% 5,005 5,005 0 0.082% 0.185% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 3 3 0 0.376% 0.517% 0.000% 1,308 1,308 0 0.026% 0.252% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.340% 0.000% 7.143% 2,671 0 2,671 0.274% 0.000% 0.386%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 54,887 0 54,887 1.193% 0.000% 1.298%MA 1 1 0 0.156% 0.190% 0.000% 60 60 0 0.001% 0.004% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 950 950 0 0.014% 0.055% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 1 1 0 0.081% 0.084% 0.000% 1,750 1,750 0 0.185% 0.442% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 1 0 1 0.144% 0.000% 2.778% 72,701 0 72,701 4.376% 0.000% 27.654%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 1 0 1 0.952% 0.000% 12.500% 68,263 0 68,263 7.563% 0.000% 9.232%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.562% 1.449% 0.000% 1,050 1,050 0 0.048% 3.695% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 0 1 0.295% 0.000% 0.694% 4,374 0 4,374 0.322% 0.000% 0.379%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 14 9 5 0.049% 0.035% 0.166% 214,983 12,087 202,896 0.117% 0.019% 0.170%

Percent of Population Served 

with At Least One Detection 

> 0.2 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.2 μg/L

Percent of Systems 

with At Least One Detection 

> 0.2 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.2 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A9d. Benzo[a]pyrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 0 1 0.552% 0.000% 2.128% 245,727 0 245,727 6.899% 0.000% 8.845%AR 2 2 0 0.441% 0.524% 0.000% 3,927 3,927 0 0.160% 0.431% 0.000%AZ 2 2 0 0.215% 0.226% 0.000% 37,296 37,296 0 0.614% 1.378% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 3 3 0 0.376% 0.517% 0.000% 1,308 1,308 0 0.026% 0.252% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.340% 0.000% 7.143% 2,671 0 2,671 0.274% 0.000% 0.386%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 6 1 5 2.479% 1.075% 3.356% 429,804 2,092 427,712 9.339% 0.557% 10.119%MA 2 1 1 0.312% 0.190% 0.855% 163,881 60 163,821 1.932% 0.004% 2.408%MD 13 10 3 1.508% 1.259% 4.412% 1,834,995 7,276 1,827,719 37.402% 0.801% 45.715%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 2 1 1 0.246% 0.133% 1.667% 31,455 300 31,155 4.176% 0.083% 7.934%NC 4 3 1 0.169% 0.135% 0.730% 5,016 2,121 2,895 0.073% 0.122% 0.056%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 2 2 0 0.162% 0.167% 0.000% 7,825 7,825 0 0.827% 1.976% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 2 1 1 0.288% 0.152% 2.778% 72,793 92 72,701 4.381% 0.007% 27.654%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.079% 0.096% 0.000% 4,000 4,000 0 0.082% 0.422% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 3 1 2 2.857% 1.031% 25.000% 119,372 109 119,263 13.226% 0.067% 16.129%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 3 3 0 1.685% 4.348% 0.000% 1,837 1,837 0 0.084% 6.464% 0.000%VT 1 1 0 0.226% 0.244% 0.000% 308 308 0 0.071% 0.169% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 5 3 2 1.475% 1.538% 1.389% 6,944 770 6,174 0.511% 0.375% 0.535%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 53 35 18 0.185% 0.137% 0.598% 2,969,159 69,321 2,899,838 1.612% 0.107% 2.435%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A10. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration or 

Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.004 mg/L 44,015 41 0.093% 84,495,418 148,433 0.176%

	
 44,015 202 0.459% 84,495,418 1,453,696 1.720%> 0.004 mg/L 4,006 12 0.300% 136,888,401 2,918,844 2.132%

	
 4,006 48 1.198% 136,888,401 4,332,647 3.165%

> 0.004 mg/L 48,021 53 0.110% 221,383,819 3,067,277 1.386%	
 48,021 250 0.521% 221,383,819 5,786,343 2.614%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A10a. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 1,493 1,060 433 1.005% 0.943% 1.155% 0.00013 0.00013 0.00079 0.0009 0.0006 0.0016 0.002 0.0019 0.0021 0.0021 0.002 0.0021AL 2,648 1,805 843 1.095% 0.554% 2.254% 0.00008 0.001 0.00008 0.001 0.001 0.001 0.002 0.0035 0.002 0.005 0.005 0.002AR 2,164 1,503 661 0.046% 0.000% 0.151% 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002AZ 6,329 4,958 1,371 0.442% 0.444% 0.438% 0.0001 0.0001 0.0001 0.001 0.001 0.00185 0.004 0.002 0.005 0.005 0.004 0.005CA 35,134 20,685 14,449 0.507% 0.503% 0.512% 2.1E-05 2.1E-05 2.1E-05 0.001 0.001 0.001 0.00218 0.002 0.003 0.03 0.006 0.03CO 4,378 2,329 2,049 1.782% 2.276% 1.220% 4.8E-05 0.00008 4.8E-05 0.001 0.001 0.0008 0.002 0.002 0.002 0.004 0.004 0.002CT 2,223 1,838 385 0.720% 0.871% 0.000% 0.0002 0.0002 0.0015 0.0015 0.004 0.004 0.01 0.01DE 691 643 48 14.616% 15.708% 0.000% 0.0001 0.0001 0.0005 0.0005 0.0011 0.0011 0.0025 0.0025FL 2,146 2,077 69 9.599% 9.870% 1.449% 0.0001 0.0001 0.0002 0.0001 0.0001 0.0002 0.001 0.001 0.0002 0.0053 0.0053 0.0002GA 2,706 2,382 324 0.000% 0.000% 0.000%HI 1,177 1,115 62 0.000% 0.000% 0.000%IA 50 31 19 0.000% 0.000% 0.000%ID 3,095 2,812 283 1.551% 1.600% 1.060% 0.0002 0.0002 0.0004 0.0005 0.0005 0.0004 0.0031 0.0031 0.0007 0.01 0.01 0.0007IL 2,783 2,384 399 0.467% 0.461% 0.501% 0.001 0.001 0.001 0.001 0.0016 0.001 0.003 0.003 0.001 0.004 0.004 0.001IN 4,716 4,235 481 2.990% 3.093% 2.079% 3.7E-05 3.7E-05 0.0001 0.0003 0.0003 0.0003 0.001 0.0008 0.00215 0.007 0.007 0.003KY 1,781 534 1,247 2.134% 2.060% 2.165% 0.0001 0.0001 0.0002 0.001 0.002 0.001 0.003 0.0025 0.003 0.05 0.003 0.05MA 2,971 2,004 967 1.548% 1.597% 1.448% 0.0002 0.0002 0.0003 0.001 0.001 0.001 0.0032 0.0026 0.004 0.004 0.004 0.004MD 5,075 3,964 1,111 0.611% 0.681% 0.360% 0.0001 0.0004 0.0001 0.001 0.001 0.01525 0.0032 0.002 0.03 0.03 0.004 0.03ME 2,313 1,928 385 1.167% 1.193% 1.039% 0.0003 0.0003 0.0003 0.0003 0.0003 0.0003 0.0005 0.0005 0.0003 0.0035 0.0035 0.0003MI 6,727 6,548 179 2.661% 2.703% 1.117% 0.0001 0.0001 0.0001 0.0001 0.0001 0.00015 0.0002 0.0002 0.0002 0.002 0.002 0.0002MN 4,436 4,357 79 0.045% 0.046% 0.000% 0.00065 0.00065 0.00133 0.00133 0.002 0.002 0.002 0.002MO 5,682 4,907 775 0.070% 0.082% 0.000% 0.00106 0.00106 0.00112 0.00112 0.00182 0.00182 0.00182 0.00182MT 3,185 2,838 347 0.283% 0.247% 0.576% 0.0001 0.0001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001NC 9,208 7,773 1,435 1.205% 1.248% 0.976% 0.0001 0.0001 0.0004 0.001 0.001 0.002 0.0027 0.003 0.0027 0.005 0.005 0.0027ND 345 303 42 1.739% 1.650% 2.381% 0.00073 0.00073 0.00149 0.00308 0.00375 0.00149 0.0045 0.0045 0.00149 0.0045 0.0045 0.00149NE 2,977 2,868 109 0.000% 0.000% 0.000%NH 3,082 2,918 164 6.100% 6.443% 0.000% 0.0004 0.0004 0.0033 0.0033 0.01 0.01 0.02 0.02NJ 6,572 5,851 721 0.776% 0.735% 1.110% 0.0001 0.0001 0.00026 0.001 0.001 0.0006 0.004 0.004 0.002 0.05 0.05 0.002NM 3,519 3,193 326 0.796% 0.752% 1.227% 0.0002 0.0002 0.0002 0.002 0.006 0.0003 0.01 0.01 0.0004 0.02 0.02 0.0004NV 2,113 1,550 563 0.615% 0.516% 0.888% 0.00023 0.00023 0.001 0.001 0.001 0.001 0.002 0.002 0.001 0.002 0.002 0.001NY 3,292 2,493 799 0.608% 0.682% 0.375% 0.00006 0.00006 0.002 0.00125 0.001 0.002 0.00285 0.002 0.004 0.004 0.0037 0.004OH 4,628 3,991 637 0.454% 0.476% 0.314% 0.00022 0.00022 0.00038 0.00035 0.00032 0.00069 0.001 0.0011 0.001 0.00177 0.00177 0.001OK 393 330 63 0.254% 0.000% 1.587% 0.0013 0.0013 0.0013 0.0013 0.0013 0.0013 0.0013 0.0013OR 1,312 953 359 0.076% 0.105% 0.000% 0.0025 0.0025 0.0025 0.0025 0.0025 0.0025 0.0025 0.0025RI 860 633 227 7.791% 10.111% 1.322% 0.0002 0.0002 0.0002 0.0004 0.0004 0.0002 0.0017 0.0017 0.0004 0.0054 0.0054 0.0004SC 3,077 2,664 413 0.422% 0.488% 0.000% 0.001 0.001 0.004 0.004 0.0054 0.0054 0.0084 0.0084SD 388 359 29 0.515% 0.557% 0.000% 0.003 0.003 0.0035 0.0035 0.004 0.004 0.004 0.004TN 1,895 668 1,227 2.902% 4.790% 1.874% 0.00003 0.0003 0.00003 0.0004 0.0004 0.00038 0.001 0.0014 0.00074 0.14 0.14 0.0021TX 14,911 12,329 2,582 0.027% 0.032% 0.000% 0.001 0.001 0.00335 0.00335 0.004 0.004 0.004 0.004UT 6,937 5,434 1,503 0.764% 0.074% 3.260% 0.0002 0.0003 0.0002 0.001 0.0009 0.001 0.0017 0.0021 0.0017 0.01 0.0021 0.01VA 2,803 2,195 608 0.606% 0.729% 0.164% 0.0005 0.0005 0.002 0.002 0.002 0.002 0.01 0.01 0.002 0.03 0.03 0.002VT 2,119 1,773 346 0.236% 0.282% 0.000% 0.0003 0.0003 0.001 0.001 0.004 0.004 0.004 0.004WI 6,992 6,821 171 5.335% 5.454% 0.585% 2.2E-05 2.2E-05 0.0002 0.00009 0.00009 0.0002 0.00053 0.00053 0.0002 0.004 0.004 0.0002WV 1,122 420 702 3.209% 4.762% 2.279% 0.0001 0.00012 0.0001 0.001 0.001 0.001 0.0011 0.001 0.007 0.01 0.001 0.01WY 1,127 876 251 0.799% 0.799% 0.797% 0.0005 0.0005 0.0006 0.0007 0.0007 0.00085 0.003 0.003 0.0011 0.003 0.003 0.0011Total 183,575 143,332 40,243 1.233% 1.348% 0.825% 2.1E-05 2.1E-05 2.1E-05 0.0005 0.0004 0.001 0.003 0.003 0.002 0.14 0.14 0.05

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A10b. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 610 467 143 592,922 230,950 361,972 2.459% 2.141% 3.497% 8.605% 21.565% 0.336%AL 352 279 73 4,701,100 1,463,066 3,238,034 4.830% 2.151% 15.068% 26.150% 1.913% 37.102%AR 453 381 72 2,452,800 909,774 1,543,026 0.221% 0.000% 1.389% 0.013% 0.000% 0.021%AZ 1,051 1,003 48 6,158,655 2,788,064 3,370,591 1.998% 1.595% 10.417% 32.913% 1.173% 59.167%CA 3,750 3,232 518 36,248,264 13,499,435 22,748,829 1.813% 1.454% 4.054% 10.064% 11.304% 9.328%CO 838 617 221 4,998,506 533,275 4,465,231 6.325% 5.997% 7.240% 17.833% 3.198% 19.581%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 1.368% 1.415% 0.000% 0.105% 0.748% 0.000%DE 281 278 3 679,823 398,423 281,400 22.420% 22.662% 0.000% 18.969% 32.366% 0.000%FL 1,335 1,309 26 17,374,897 15,128,855 2,246,042 11.011% 11.154% 3.846% 28.888% 33.158% 0.126%GA 1,593 1,479 114 7,242,523 1,350,192 5,892,331 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 107 95 12 1,303,767 1,249,139 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 26 17 9 550,757 40,080 510,677 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 924 875 49 1,078,426 833,516 244,910 4.329% 4.343% 4.082% 15.564% 18.388% 5.952%IL 1,241 1,140 101 9,078,639 2,879,411 6,199,228 0.967% 0.877% 1.980% 41.167% 0.984% 59.831%IN 1,623 1,574 49 4,980,057 2,619,602 2,360,455 7.394% 7.116% 16.327% 15.905% 12.690% 19.472%KY 242 93 149 4,602,489 375,460 4,227,029 12.810% 9.677% 14.765% 30.400% 27.072% 30.696%MA 676 558 118 8,525,575 1,718,151 6,807,424 4.290% 3.943% 5.932% 44.526% 6.093% 54.227%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 2.505% 2.371% 4.412% 39.893% 28.140% 42.905%ME 802 748 54 727,134 291,530 435,604 3.367% 3.075% 7.407% 2.585% 1.392% 3.383%MI 3,033 2,980 53 6,717,830 1,925,399 4,792,431 5.407% 5.436% 3.774% 9.781% 15.642% 7.426%MN 1,593 1,564 29 4,265,162 3,015,521 1,249,641 0.126% 0.128% 0.000% 0.500% 0.708% 0.000%MO 1,421 1,344 77 3,006,743 1,692,282 1,314,461 0.281% 0.298% 0.000% 0.206% 0.366% 0.000%MT 849 789 60 757,930 365,261 392,669 0.824% 0.760% 1.667% 5.358% 2.588% 7.934%NC 2,284 2,145 139 6,973,609 1,708,443 5,265,166 4.291% 4.009% 8.633% 11.011% 7.487% 12.155%ND 217 190 27 563,069 257,844 305,225 2.765% 2.632% 3.704% 0.524% 0.999% 0.122%NE 743 732 11 1,450,223 673,743 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,216 1,175 41 942,517 392,718 549,799 1.645% 1.702% 0.000% 0.405% 0.971% 0.000%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 3.275% 2.842% 18.919% 18.075% 9.738% 22.588%NM 724 685 39 1,667,433 1,400,885 266,548 1.519% 1.460% 2.564% 28.874% 33.597% 4.052%NV 335 314 21 973,342 283,451 689,891 2.985% 2.229% 14.286% 40.492% 0.936% 56.744%NY 1,551 1,315 236 4,377,347 1,214,207 3,163,140 1.225% 1.293% 0.847% 1.469% 4.159% 0.437%OH 1,931 1,806 125 10,224,557 3,129,620 7,094,937 1.036% 0.997% 1.600% 2.281% 0.419% 3.102%OK 182 166 16 679,606 268,651 410,955 0.549% 0.000% 6.250% 0.221% 0.000% 0.365%OR 731 610 121 2,770,064 486,818 2,283,246 0.137% 0.164% 0.000% 0.002% 0.009% 0.000%RI 143 134 9 913,584 173,606 739,978 19.580% 19.403% 22.222% 11.416% 44.411% 3.674%SC 800 735 65 3,464,762 806,235 2,658,527 1.500% 1.633% 0.000% 0.599% 2.576% 0.000%SD 234 223 11 339,259 247,298 91,961 0.855% 0.897% 0.000% 0.040% 0.055% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 10.826% 10.494% 11.111% 13.378% 7.009% 15.584%TX 4,930 4,587 343 25,070,435 9,285,450 15,784,985 0.061% 0.065% 0.000% 0.001% 0.002% 0.000%UT 507 457 50 2,543,652 1,686,017 857,635 0.986% 0.875% 2.000% 12.644% 0.570% 36.379%VA 1,582 1,414 168 4,803,450 634,384 4,169,066 0.822% 0.849% 0.595% 0.155% 0.771% 0.061%VT 601 558 43 490,989 227,021 263,968 0.666% 0.717% 0.000% 0.167% 0.362% 0.000%WI 1,822 1,802 20 4,043,916 2,352,172 1,691,744 14.160% 14.262% 5.000% 6.055% 9.951% 0.638%WV 451 290 161 1,415,477 234,687 1,180,790 7.095% 6.897% 7.453% 2.837% 1.698% 3.063%WY 304 255 49 446,184 129,168 317,016 2.632% 2.353% 4.082% 3.464% 1.059% 4.443%Total 48,021 44,015 4,006 221,383,819 84,495,418 136,888,401 3.117% 2.992% 4.493% 13.780% 11.296% 15.313%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A10c. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 1 0 0.284% 0.358% 0.000% 450 450 0 0.010% 0.031% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 2 0 2 0.190% 0.000% 4.167% 700 0 700 0.011% 0.000% 0.021%CA 6 1 5 0.160% 0.031% 0.965% 5,079 273 4,806 0.014% 0.002% 0.021%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.085% 0.088% 0.000% 48 48 0 0.002% 0.013% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.075% 0.076% 0.000% 56,055 56,055 0 0.323% 0.371% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 3 3 0 0.325% 0.343% 0.000% 49,871 49,871 0 4.624% 5.983% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 4 4 0 0.246% 0.254% 0.000% 1,044 1,044 0 0.021% 0.040% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 886,428 0 886,428 19.260% 0.000% 20.970%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 0 1 0.096% 0.000% 1.471% 1,710,000 0 1,710,000 34.047% 0.000% 42.770%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 3 0 0.131% 0.140% 0.000% 1,587 1,587 0 0.023% 0.093% 0.000%ND 2 2 0 0.922% 1.053% 0.000% 792 792 0 0.141% 0.307% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 11 11 0 0.905% 0.936% 0.000% 1,432 1,432 0 0.152% 0.365% 0.000%NJ 4 4 0 0.291% 0.299% 0.000% 16,984 16,984 0 0.219% 0.623% 0.000%NM 1 1 0 0.138% 0.146% 0.000% 300 300 0 0.018% 0.021% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 1 1 0 0.699% 0.746% 0.000% 25 25 0 0.003% 0.014% 0.000%SC 5 5 0 0.625% 0.680% 0.000% 18,888 18,888 0 0.545% 2.343% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 1 0 0.285% 0.617% 0.000% 500 500 0 0.009% 0.034% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 1 0 1 0.197% 0.000% 2.000% 312,000 0 312,000 12.266% 0.000% 36.379%VA 2 2 0 0.126% 0.141% 0.000% 184 184 0 0.004% 0.029% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 0 2 0.443% 0.000% 1.242% 4,910 0 4,910 0.347% 0.000% 0.416%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 53 41 12 0.110% 0.093% 0.300% 3,067,277 148,433 2,918,844 1.386% 0.176% 2.132%

Percent of Population Served 

with At Least One Detection 

> 0.004 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.004 mg/L

Percent of Systems 

with At Least One Detection 

> 0.004 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.004 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A10d. Beryllium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 3 1 2 0.492% 0.214% 1.399% 47,943 47,290 653 8.086% 20.476% 0.180%AL 5 2 3 1.420% 0.717% 4.110% 130,453 2,131 128,322 2.775% 0.146% 3.963%AR 1 0 1 0.221% 0.000% 1.389% 322 0 322 0.013% 0.000% 0.021%AZ 9 6 3 0.856% 0.598% 6.250% 312,265 11,565 300,700 5.070% 0.415% 8.921%CA 20 11 9 0.533% 0.340% 1.737% 619,385 144,012 475,373 1.709% 1.067% 2.090%CO 9 6 3 1.074% 0.972% 1.357% 304,648 2,648 302,000 6.095% 0.497% 6.763%CT 8 8 0 0.684% 0.707% 0.000% 2,077 2,077 0 0.076% 0.543% 0.000%DE 3 3 0 1.068% 1.079% 0.000% 1,250 1,250 0 0.184% 0.314% 0.000%FL 4 4 0 0.300% 0.306% 0.000% 239,239 239,239 0 1.377% 1.581% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 6 6 0 0.649% 0.686% 0.000% 65,695 65,695 0 6.092% 7.882% 0.000%IL 5 5 0 0.403% 0.439% 0.000% 10,837 10,837 0 0.119% 0.376% 0.000%IN 9 8 1 0.555% 0.508% 2.041% 115,821 114,037 1,784 2.326% 4.353% 0.076%KY 11 5 6 4.545% 5.376% 4.027% 957,616 1,456 956,160 20.806% 0.388% 22.620%MA 12 8 4 1.775% 1.434% 3.390% 144,576 76,370 68,206 1.696% 4.445% 1.002%MD 8 7 1 0.771% 0.722% 1.471% 1,711,392 1,392 1,710,000 34.075% 0.136% 42.770%ME 1 1 0 0.125% 0.134% 0.000% 190 190 0 0.026% 0.065% 0.000%MI 1 1 0 0.033% 0.034% 0.000% 150 150 0 0.002% 0.008% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 21,000 21,000 0 0.492% 0.696% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 35 29 6 1.532% 1.352% 4.317% 57,304 24,166 33,138 0.822% 1.415% 0.629%ND 4 4 0 1.843% 2.105% 0.000% 2,430 2,430 0 0.432% 0.942% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 19 19 0 1.563% 1.617% 0.000% 3,783 3,783 0 0.401% 0.963% 0.000%NJ 14 13 1 1.019% 0.972% 2.703% 101,806 101,676 130 1.312% 3.729% 0.003%NM 5 5 0 0.691% 0.730% 0.000% 461,146 461,146 0 27.656% 32.918% 0.000%NV 2 2 0 0.597% 0.637% 0.000% 153 153 0 0.016% 0.054% 0.000%NY 8 6 2 0.516% 0.456% 0.847% 59,147 45,320 13,827 1.351% 3.732% 0.437%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 1 1 0 0.137% 0.164% 0.000% 42 42 0 0.002% 0.009% 0.000%RI 5 5 0 3.497% 3.731% 0.000% 38,552 38,552 0 4.220% 22.207% 0.000%SC 11 11 0 1.375% 1.497% 0.000% 20,367 20,367 0 0.588% 2.526% 0.000%SD 2 2 0 0.855% 0.897% 0.000% 135 135 0 0.040% 0.055% 0.000%TN 3 2 1 0.855% 1.235% 0.529% 31,242 8,788 22,454 0.550% 0.601% 0.532%TX 2 2 0 0.041% 0.044% 0.000% 52 52 0 0.000% 0.001% 0.000%UT 2 1 1 0.394% 0.219% 2.000% 312,118 118 312,000 12.270% 0.007% 36.379%VA 11 10 1 0.695% 0.707% 0.595% 6,446 3,908 2,538 0.134% 0.616% 0.061%VT 1 1 0 0.166% 0.179% 0.000% 468 468 0 0.095% 0.206% 0.000%WI 5 5 0 0.274% 0.277% 0.000% 1,218 1,218 0 0.030% 0.052% 0.000%WV 3 0 3 0.665% 0.000% 1.863% 5,040 0 5,040 0.356% 0.000% 0.427%WY 1 1 0 0.329% 0.392% 0.000% 35 35 0 0.008% 0.027% 0.000%Total 250 202 48 0.521% 0.459% 1.198% 5,786,343 1,453,696 4,332,647 2.614% 1.720% 3.165%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A11. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 50 pCi/L 12,505 68 0.544% 31,262,033 540,849 1.730%
	
 12,505 302 2.415% 31,262,033 1,662,946 5.319%

> 50 pCi/L 1,726 7 0.406% 89,012,891 936,487 1.052%
	
 1,726 33 1.912% 89,012,891 7,998,101 8.985%

> 50 pCi/L 14,231 75 0.527% 120,274,924 1,477,336 1.228%


	
 14,231 335 2.354% 120,274,924 9,661,047 8.032%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A11a. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 204 156 48 89.216% 89.744% 87.500% 0.00001 0.00001 0.08 2.7 2.95 1.6 7.3 7.5 4.4 10 10 5.7AL 375 215 160 49.067% 47.442% 51.250% 0.003 0.009 0.003 2.8 3.2 2.35 5 5.3 4.4 29.1 29.1 7.67AR 2,521 1,908 613 46.886% 46.751% 47.308% 0.1 0.1 0.1 2.3 2.6 1.9 5 5.5 3.6 18 18 12AZ 375 92 283 0.000% 0.000% 0.000%CA 5,499 1,685 3,814 64.321% 73.531% 60.252% 0.01 0.01 0.01 3.74 3.29 4.02 9 8.4 9.06 488 72 488CO 2,303 1,658 645 72.384% 74.427% 67.132% 0.04 0.1 0.04 5 6 3.2 18 20.02 9 310 310 180CT 232 195 37 55.172% 56.410% 48.649% 0.38 1.14 0.38 5.785 6.485 1.27 14.5 16.3 3.36 272.3 272.3 7.42DE 24 0 24 29.167% 0.000% 29.167% 2.8 2.8 4.7 4.7 6.42 6.42 6.42 6.42FLGAHIIA 9 3 6 88.889% 100.000% 83.333% 2.3 5.5 2.3 4.7 8.5 2.9 13.1 13.1 8.9 13.1 13.1 8.9ID 1,774 1,500 274 94.589% 94.733% 93.796% 0.01 0.1 0.01 5.7 6 3.9 16.4 17.7 10.3 183.1 183.1 26.9IL 7,490 6,972 518 74.593% 74.068% 81.660% 1 1 1 11 12 4 26 26 8 92 92 13IN 128 128 0 97.656% 97.656% 0.000% 0.1 0.1 2.2 2.2 7.3 7.3 17.1 17.1KY 68 10 58 92.647% 80.000% 94.828% 1.1 1.7 1.1 2.9 6.15 2.8 4.5 54 4.2 54 54 7.9MA 558 333 225 87.097% 90.390% 82.222% 0.1 0.1 0.1 5 5.5 4.29 26 27.1 23 140 140 54MD 1,709 1,357 352 71.913% 75.903% 56.534% 1 1 1 5 6 3 13 13 6 72 72 60MEMIMN 1,121 1,098 23 93.310% 93.716% 73.913% 0.62 0.62 0.93 5.2 5.3 2.6 13.8 13.9 3.8 34 34 5.5MO 63 63 0 82.540% 82.540% 0.000% 1.2 1.2 2.95 2.95 5.4 5.4 22.8 22.8MT 17 13 4 70.588% 69.231% 75.000% 0.79 1.2 0.79 2.85 4 2 9.6 11 2.7 11 11 2.7NC 8,111 7,588 523 42.892% 42.818% 43.977% 0.02 0.02 0.06 5.21 5.44 2.44 13.75 14.23 5.4 340.5 340.5 11.8NDNENHNJ 53 21 32 100.000% 100.000% 100.000% 0.09 1.4 0.09 3.5 5.2 2.75 16 16 15 136 136 103NM 2,815 2,635 180 95.631% 95.863% 92.222% 0.1 0.1 0.3 5.3 5.535 2.8 15.47 15.92 6.5 86 86 43.8NV 1,731 1,515 216 82.727% 84.158% 72.685% 0.02 0.02 0.02 5.9 6 4.5 12.7 13 9.5 102 102 16NY 2,047 1,741 306 85.393% 85.181% 86.601% 0.02 0.02 0.08 3.4 3.8 2.2 9.1 9.4 5.3 228 228 28OH 841 272 569 32.105% 26.838% 34.622% 1.03 1.03 1.15 5.595 5.88 5.53 8.515 10.4 8.3 20.7 18.2 20.7OKOR 53 38 15 60.377% 60.526% 60.000% 1.84 1.94 1.84 4.3 4.46 3.2 8.5 9.59 6.7 13.2 13.2 6.7RI 362 304 58 77.348% 76.316% 82.759% 0.51 0.51 1.17 3.375 3.54 2.5 6.62 7 4.2 186.49 186.49 10.85SCSD 2 1 1 50.000% 0.000% 100.000% 12.2 12.2 12.2 12.2 12.2 12.2 12.2 12.2TNTX 12,450 10,943 1,507 45.944% 44.339% 57.598% 3.7 3.7 4 7.2 7.5 6.2 16.5 17.1 11.9 120.5 120.5 74.1UT 3,029 2,506 523 70.221% 69.593% 73.231% 0.3 0.3 1 3 3 4 9 9 9 66 66 31VA 1,489 1,234 255 99.328% 99.433% 98.824% 0.2 0.2 0.2 3.6 3.9 2.2 9 9.4 4.9 50.7 50.7 9.9VT 3 3 0 66.667% 66.667% 0.000% 0.12 0.12 0.91 0.91 1.7 1.7 1.7 1.7WI 2,487 2,420 67 86.691% 86.529% 92.537% 0.03 0.03 0.8 3.5 3.5 7.35 12 12 14 106 106 21.3WV 39 14 25 97.436% 100.000% 96.000% 0.5 0.9 0.5 2.05 2.05 2.1 3.9 3.7 6.4 8.7 3.9 8.7WY 1 1 0 0.000% 0.000% 0.000%Total 59,983 48,622 11,361 64.488% 65.143% 61.685% 0.00001 0.00001 0.003 5.2 5.8 4 16.09 17.8 9.06 488 340.5 488

Median Detect 

Concentration (pCi/L)

Maximum Detect 

Concentration (pCi/L)

90th Percentile Detect 

Concentration (pCi/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (pCi/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A11b. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 65 47 18 41,281 24,253 17,028 86.154% 85.106% 88.889% 72.498% 66.969% 80.374%AL 69 44 25 1,643,459 310,659 1,332,800 69.565% 61.364% 84.000% 91.404% 82.366% 93.510%AR 372 310 62 2,125,964 754,780 1,371,184 94.086% 93.548% 96.774% 93.811% 86.594% 97.784%AZ 22 14 8 2,687,913 146,838 2,541,075 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CA 312 179 133 22,507,285 4,121,434 18,385,851 88.141% 86.034% 90.977% 91.788% 81.824% 94.021%CO 665 473 192 4,902,486 482,291 4,420,195 78.647% 79.704% 76.042% 88.923% 84.482% 89.408%CT 50 44 6 1,354,974 45,804 1,309,170 88.000% 90.909% 66.667% 71.394% 89.453% 70.762%DE 3 0 3 281,400 0 281,400 66.667% 0.000% 66.667% 87.161% 0.000% 87.161%FLGAHIIA 6 3 3 486,665 27,140 459,525 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%ID 592 545 47 1,000,626 748,550 252,076 95.946% 95.963% 95.745% 94.012% 92.436% 98.692%IL 1,067 977 90 5,275,541 2,904,400 2,371,141 61.949% 59.365% 90.000% 81.286% 73.105% 91.307%IN 32 32 0 81,650 81,650 0 96.875% 96.875% 0.000% 94.080% 94.080% 0.000%KY 22 3 19 1,836,280 9,101 1,827,179 90.909% 66.667% 94.737% 97.675% 46.511% 97.930%MA 212 140 72 6,370,032 513,689 5,856,343 91.038% 89.286% 94.444% 97.526% 88.667% 98.303%MD 515 458 57 4,891,537 898,753 3,992,784 84.660% 84.061% 89.474% 99.264% 97.989% 99.551%MEMIMN 687 664 23 3,655,448 2,409,587 1,245,861 93.159% 93.825% 73.913% 94.232% 92.007% 98.536%MO 50 50 0 10,302 10,302 0 88.000% 88.000% 0.000% 86.197% 86.197% 0.000%MT 11 7 4 81,975 10,048 71,927 81.818% 85.714% 75.000% 98.933% 95.273% 99.444%NC 1,660 1,534 126 6,726,126 1,512,232 5,213,894 71.265% 69.492% 92.857% 91.244% 77.199% 95.318%NDNENHNJ 37 16 21 3,704,577 186,696 3,517,881 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%NM 566 533 33 1,613,612 1,348,169 265,443 98.763% 98.687% 100.000% 99.936% 99.924% 100.000%NV 212 195 17 909,274 243,678 665,596 91.509% 91.282% 94.118% 99.611% 98.793% 99.910%NY 886 739 147 4,698,625 855,337 3,843,288 82.619% 82.003% 85.714% 61.883% 93.099% 54.936%OH 300 181 119 7,721,824 840,967 6,880,857 48.333% 26.519% 81.513% 75.287% 28.879% 80.958%OKOR 34 26 8 170,477 53,652 116,825 61.765% 57.692% 75.000% 94.376% 95.849% 93.700%RI 63 55 8 885,694 146,256 739,438 95.238% 96.364% 87.500% 99.060% 99.854% 98.903%SCSD 2 1 1 142,862 14,736 128,126 50.000% 0.000% 100.000% 89.685% 0.000% 100.000%TNTX 3,989 3,662 327 24,786,365 9,009,970 15,776,395 53.422% 51.283% 77.370% 83.590% 68.318% 92.312%UT 323 292 31 2,162,558 1,459,864 702,694 84.520% 86.301% 67.742% 95.945% 96.380% 95.042%VA 574 480 94 3,916,167 270,517 3,645,650 99.652% 99.792% 98.936% 99.875% 99.959% 99.869%VT 1 1 0 88 88 0 100.000% 100.000% 0.000% 100.000% 100.000% 0.000%WI 798 786 12 3,233,657 1,763,714 1,469,943 94.737% 94.656% 100.000% 99.107% 98.362% 100.000%WV 33 13 20 368,173 56,851 311,322 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%WY 1 1 0 27 27 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 14,231 12,505 1,726 120,274,924 31,262,033 89,012,891 74.513% 72.971% 85.689% 86.861% 80.112% 89.231%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A11c. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 4 2 2 1.282% 1.117% 1.504% 673,000 433,500 239,500 2.990% 10.518% 1.303%CO 6 5 1 0.902% 1.057% 0.521% 4,738 4,038 700 0.097% 0.837% 0.016%CT 2 2 0 4.000% 4.545% 0.000% 396 396 0 0.029% 0.865% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FLGAHIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 4 4 0 0.676% 0.734% 0.000% 790 790 0 0.079% 0.106% 0.000%IL 6 6 0 0.562% 0.614% 0.000% 6,533 6,533 0 0.124% 0.225% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 1 0 4.545% 33.333% 0.000% 2,303 2,303 0 0.125% 25.305% 0.000%MA 5 4 1 2.358% 2.857% 1.389% 11,847 1,414 10,433 0.186% 0.275% 0.178%MD 2 1 1 0.388% 0.218% 1.754% 4,675 675 4,000 0.096% 0.075% 0.100%MEMIMN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 13 13 0 0.783% 0.847% 0.000% 5,296 5,296 0 0.079% 0.350% 0.000%NDNENHNJ 2 1 1 5.405% 6.250% 4.762% 681,154 4,900 676,254 18.387% 2.625% 19.223%NM 7 7 0 1.237% 1.313% 0.000% 21,666 21,666 0 1.343% 1.607% 0.000%NV 1 1 0 0.472% 0.513% 0.000% 180 180 0 0.020% 0.074% 0.000%NY 3 3 0 0.339% 0.406% 0.000% 1,971 1,971 0 0.042% 0.230% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 1 1 0 1.587% 1.818% 0.000% 100 100 0 0.011% 0.068% 0.000%SCSD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TNTX 14 13 1 0.351% 0.355% 0.306% 21,177 15,577 5,600 0.085% 0.173% 0.035%UT 1 1 0 0.310% 0.342% 0.000% 26,000 26,000 0 1.202% 1.781% 0.000%VA 1 1 0 0.174% 0.208% 0.000% 590 590 0 0.015% 0.218% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.251% 0.254% 0.000% 14,920 14,920 0 0.461% 0.846% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Total 75 68 7 0.527% 0.544% 0.406% 1,477,336 540,849 936,487 1.228% 1.730% 1.052%

Percent of Population Served 

with At Least One Detection 

> 50 pCi/L

State

Number of Systems 

with At Least One Detection 

> 50 pCi/L

Percent of Systems 

with At Least One Detection 

> 50 pCi/L

Population Served by Systems 

with At Least One Detection 

> 50 pCi/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A11d. Beta Particles – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 1 0 1.449% 2.273% 0.000% 4,170 4,170 0 0.254% 1.342% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 14 3 11 4.487% 1.676% 8.271% 7,349,183 473,415 6,875,768 32.652% 11.487% 37.397%CO 24 19 5 3.609% 4.017% 2.604% 156,424 29,763 126,661 3.191% 6.171% 2.866%CT 4 4 0 8.000% 9.091% 0.000% 1,052 1,052 0 0.078% 2.297% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FLGAHIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 19 18 1 3.209% 3.303% 2.128% 19,349 18,740 609 1.934% 2.504% 0.242%IL 74 74 0 6.935% 7.574% 0.000% 514,292 514,292 0 9.749% 17.707% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 1 0 4.545% 33.333% 0.000% 2,303 2,303 0 0.125% 25.305% 0.000%MA 28 21 7 13.208% 15.000% 9.722% 268,634 144,200 124,434 4.217% 28.071% 2.125%MD 5 3 2 0.971% 0.655% 3.509% 112,717 4,150 108,567 2.304% 0.462% 2.719%MEMIMN 3 3 0 0.437% 0.452% 0.000% 20,190 20,190 0 0.552% 0.838% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 22 22 0 1.325% 1.434% 0.000% 10,713 10,713 0 0.159% 0.708% 0.000%NDNENHNJ 2 1 1 5.405% 6.250% 4.762% 681,154 4,900 676,254 18.387% 2.625% 19.223%NM 28 27 1 4.947% 5.066% 3.030% 121,004 120,771 233 7.499% 8.958% 0.088%NV 9 9 0 4.245% 4.615% 0.000% 36,676 36,676 0 4.034% 15.051% 0.000%NY 7 6 1 0.790% 0.812% 0.680% 4,122 2,522 1,600 0.088% 0.295% 0.042%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 2 2 0 3.175% 3.636% 0.000% 1,650 1,650 0 0.186% 1.128% 0.000%SCSD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TNTX 75 72 3 1.880% 1.966% 0.917% 78,760 70,825 7,935 0.318% 0.786% 0.050%UT 7 6 1 2.167% 2.055% 3.226% 195,942 119,902 76,040 9.061% 8.213% 10.821%VA 3 3 0 0.523% 0.625% 0.000% 908 908 0 0.023% 0.336% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 7 7 0 0.877% 0.891% 0.000% 81,804 81,804 0 2.530% 4.638% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 335 302 33 2.354% 2.415% 1.912% 9,661,047 1,662,946 7,998,101 8.032% 5.319% 8.985%

Percent of Population Served 

with At Least One Detection 


	


State

Number of Systems 

with At Least One Detection 


	


Percent of Systems 

with At Least One Detection 


	


Population Served by Systems 

with At Least One Detection 


	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A12. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.005 mg/L 44,928 121 0.269% 85,335,776 497,363 0.583%

	
 44,928 407 0.906% 85,335,776 1,710,771 2.005%

> 0.005 mg/L 3,992 13 0.326% 144,349,594 1,901,706 1.317%

	
 3,992 59 1.478% 144,349,594 4,288,872 2.971%

> 0.005 mg/L 48,920 134 0.274% 229,685,370 2,399,069 1.045%

	
 48,920 466 0.953% 229,685,370 5,999,643 2.612%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A12a. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 877 619 258 4.333% 4.200% 4.651% 0.0001 0.0001 0.0001 0.00015 0.00015 0.00016 0.00098 0.00098 0.00091 0.00264 0.00135 0.00264AL 2,671 1,814 857 0.824% 0.662% 1.167% 0.0004 0.0004 0.0008 0.003 0.003 0.003 0.004 0.004 0.0045 0.005 0.004 0.005AR 2,192 1,538 654 0.319% 0.390% 0.153% 0.001 0.001 0.001 0.001 0.001 0.001 0.005 0.005 0.001 0.005 0.005 0.001AZ 6,332 4,951 1,381 1.453% 1.555% 1.086% 0.0001 0.0001 0.0001 0.0014 0.0015 0.0013 0.005 0.0055 0.0041 0.05 0.05 0.005CA 35,018 20,753 14,265 1.345% 1.648% 0.904% 6E-06 6E-06 7E-06 0.001 0.001 0.00115 0.003 0.003 0.003 0.04 0.02 0.04CO 4,388 2,328 2,060 3.624% 3.436% 3.835% 0.00003 0.00004 0.00003 0.0003 0.0003 0.00029 0.0012 0.0009 0.0022 0.0081 0.0013 0.0081CT 2,601 1,878 723 1.922% 1.491% 3.043% 0.0002 0.0002 0.0004 0.002 0.0021 0.002 0.005 0.0074 0.002 0.02 0.02 0.009DE 689 641 48 9.144% 9.828% 0.000% 0.0001 0.0001 0.0004 0.0004 0.0008 0.0008 0.0021 0.0021FL 2,141 2,072 69 5.138% 5.309% 0.000% 0.0001 0.0001 0.0005 0.0005 0.00115 0.00115 0.0046 0.0046GA 2,705 2,382 323 0.074% 0.084% 0.000% 0.0032 0.0032 0.0065 0.0065 0.0098 0.0098 0.0098 0.0098HI 1,163 1,101 62 0.344% 0.272% 1.613% 0.0003 0.0003 0.0004 0.0008 0.0012 0.0004 0.003 0.003 0.0004 0.003 0.003 0.0004IA 1,522 1,259 263 0.526% 0.635% 0.000% 0.001 0.001 0.004 0.004 0.01 0.01 0.01 0.01ID 2,665 2,390 275 2.402% 2.636% 0.364% 0.00001 0.00001 0.0008 0.0007 0.0007 0.0008 0.0021 0.0021 0.0008 0.007 0.007 0.0008IL 3,486 3,072 414 5.192% 5.534% 2.657% 0.00033 0.00033 0.002 0.004 0.004 0.0039 0.007 0.00705 0.007 0.04 0.04 0.007IN 4,704 4,222 482 5.145% 5.471% 2.282% 0.0001 0.0001 0.0001 0.0009 0.0009 0.0003 0.0033 0.0033 0.0011 0.005 0.005 0.0017KY 1,786 550 1,236 5.375% 3.273% 6.311% 0.00007 0.00007 0.0001 0.0002 0.00125 0.0002 0.0025 0.003 0.002 0.05 0.0032 0.05MA 2,964 1,995 969 2.328% 2.406% 2.167% 0.00004 0.0002 0.00004 0.001 0.001 0.001 0.002 0.002 0.0011 0.01 0.01 0.006MD 5,108 3,991 1,117 1.018% 0.752% 1.970% 0.00001 0.0005 0.00001 0.001 0.00105 0.001 0.0031 0.0038 0.003 0.008 0.008 0.0032ME 2,710 2,311 399 1.218% 1.385% 0.251% 0.0005 0.0005 0.0005 0.0011 0.0011 0.0005 0.0032 0.0032 0.0005 0.0076 0.0076 0.0005MI 6,143 5,969 174 8.888% 8.996% 5.172% 0.00002 0.00002 0.0001 0.0001 0.0001 0.0001 0.0003 0.0003 0.0002 0.01 0.01 0.0002MN 3,331 3,282 49 0.630% 0.609% 2.041% 0.00051 0.00051 0.00083 0.0011 0.00113 0.00083 0.00377 0.00439 0.00083 0.03 0.03 0.00083MO 5,803 5,028 775 2.171% 2.486% 0.129% 0.001 0.001 0.00151 0.00316 0.00317 0.00151 0.01 0.01 0.00151 0.03 0.03 0.00151MT 2,737 2,449 288 0.804% 0.735% 1.389% 0.0001 0.0001 0.0002 0.001 0.001 0.00055 0.002 0.004 0.001 0.01 0.01 0.001NC 9,235 7,794 1,441 1.841% 1.809% 2.012% 0.00005 0.00005 0.00005 0.001 0.001 0.001 0.002 0.002 0.002 0.02 0.007 0.02ND 347 303 44 0.576% 0.660% 0.000% 0.00071 0.00071 0.00092 0.00092 0.00112 0.00112 0.00112 0.00112NE 1,884 1,798 86 0.000% 0.000% 0.000%NH 2,932 2,767 165 1.160% 1.193% 0.606% 0.001 0.001 0.0016 0.0016 0.0016 0.0016 0.01 0.01 0.0016 0.03 0.03 0.0016NJ 6,605 5,885 720 1.862% 1.903% 1.528% 0.00003 0.0001 0.00003 0.001 0.0011 0.0005 0.004 0.004 0.003 0.03 0.03 0.007NM 3,522 3,196 326 7.524% 7.697% 5.828% 0.0001 0.0001 0.0001 0.0002 0.0002 0.0002 0.003 0.003 0.0011 0.04 0.04 0.0033NV 1,906 1,332 574 0.892% 0.901% 0.871% 0.0002 0.0002 0.001 0.001 0.001 0.001 0.02 0.02 0.002 0.04 0.04 0.002NY 3,396 2,541 855 0.618% 0.590% 0.702% 0.00002 0.00002 0.0009 0.0017 0.002 0.0012 0.005 0.005 0.003 0.0095 0.0095 0.003OH 4,106 3,460 646 1.120% 1.272% 0.310% 0.00017 0.00017 0.00026 0.00075 0.00075 0.00063 0.01 0.01 0.001 0.01 0.01 0.001OK 393 330 63 0.509% 0.606% 0.000% 0.003 0.003 0.0055 0.0055 0.008 0.008 0.008 0.008OR 1,317 953 364 0.607% 0.735% 0.275% 0.00003 5.5E-05 0.00003 0.00053 0.00066 0.00003 0.0032 0.0032 0.00003 0.0032 0.0032 0.00003RI 891 660 231 2.132% 0.909% 5.628% 0.00002 0.00002 0.001 0.0017 0.00215 0.0017 0.0027 0.0026 0.0027 0.0042 0.0026 0.0042SC 3,446 2,982 464 5.775% 6.103% 3.664% 0.0001 0.0001 0.0001 0.0002 0.0002 0.00018 0.00065 0.00065 0.0004 0.003 0.0026 0.003SD 389 360 29 3.085% 3.333% 0.000% 0.0002 0.0002 0.0009 0.0009 0.0012 0.0012 0.0018 0.0018TN 1,658 486 1,172 5.006% 0.206% 6.997% 0.0001 0.0013 0.0001 0.0002 0.0013 0.0002 0.0007 0.0013 0.00069 0.003 0.0013 0.003TX 14,758 12,178 2,580 0.271% 0.255% 0.349% 0.0002 0.0003 0.0002 0.00154 0.00158 0.0013 0.00416 0.0041 0.005 0.01 0.01 0.005UT 7,022 5,477 1,545 1.438% 0.895% 3.366% 0.001 0.001 0.001 0.002 0.002 0.002 0.003 0.003 0.003 0.02 0.02 0.005VA 2,809 2,199 610 0.356% 0.409% 0.164% 0.002 0.002 0.002 0.002 0.002 0.002 0.0165 0.03 0.002 0.03 0.03 0.002VT 2,059 1,735 324 0.729% 0.865% 0.000% 0.00008 0.00008 0.001 0.001 0.002 0.002 0.003 0.003WI 7,011 6,840 171 4.621% 4.678% 2.339% 1.1E-05 1.1E-05 0.00014 0.00024 0.00024 0.00024 0.00087 0.00086 0.0011 0.08 0.08 0.0011WV 1,113 422 691 2.516% 3.791% 1.737% 9.7E-06 9.7E-06 3.1E-05 0.001 0.001 0.00018 0.001 0.001 0.0013 0.0025 0.001 0.0025WY 1,132 877 255 2.739% 3.079% 1.569% 0.0005 0.0005 0.0009 0.0019 0.0019 0.00145 0.0033 0.0033 0.0038 0.01 0.01 0.0038Total 181,667 141,170 40,497 2.217% 2.360% 1.721% 6E-06 6E-06 7E-06 0.00054 0.0005 0.00085 0.0035 0.004 0.003 0.08 0.08 0.05

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A12b. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 496 394 102 551,465 211,445 340,020 7.056% 6.091% 10.784% 1.836% 3.385% 0.873%AL 352 279 73 4,701,100 1,463,066 3,238,034 4.830% 2.867% 12.329% 10.857% 3.178% 14.327%AR 453 381 72 2,452,800 909,774 1,543,026 1.545% 1.575% 1.389% 1.118% 2.861% 0.091%AZ 1,050 1,002 48 6,162,056 2,791,465 3,370,591 4.857% 4.491% 12.500% 52.470% 34.921% 67.004%CA 3,819 3,296 523 36,244,015 13,414,446 22,829,569 5.918% 4.945% 12.046% 21.099% 15.545% 24.363%CO 838 617 221 4,998,506 533,275 4,465,231 12.411% 10.049% 19.005% 51.863% 9.364% 56.939%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 2.821% 2.299% 17.949% 25.753% 6.327% 28.935%DE 281 278 3 679,823 398,423 281,400 13.879% 14.029% 0.000% 18.419% 31.429% 0.000%FL 1,334 1,308 26 17,251,146 15,005,104 2,246,042 6.522% 6.651% 0.000% 25.960% 29.845% 0.000%GA 1,593 1,479 114 7,242,523 1,350,192 5,892,331 0.126% 0.135% 0.000% 2.272% 12.188% 0.000%HI 107 95 12 1,303,767 1,249,139 54,628 2.804% 2.105% 8.333% 2.380% 2.466% 0.403%IA 966 933 33 2,500,215 1,391,589 1,108,626 0.828% 0.857% 0.000% 0.207% 0.372% 0.000%ID 896 848 48 1,048,836 805,867 242,969 5.134% 5.307% 2.083% 26.538% 11.458% 76.553%IL 1,489 1,386 103 9,168,084 2,968,012 6,200,072 10.477% 10.534% 9.709% 7.846% 16.578% 3.667%IN 1,623 1,574 49 4,980,057 2,619,602 2,360,455 13.124% 13.024% 16.327% 14.809% 14.486% 15.168%KY 242 93 149 4,602,489 375,460 4,227,029 20.661% 13.978% 24.832% 40.978% 40.734% 41.000%MA 675 557 118 8,525,540 1,718,116 6,807,424 6.519% 5.566% 11.017% 48.204% 5.674% 58.937%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 2.890% 2.577% 7.353% 35.767% 4.058% 43.892%ME 807 753 54 727,775 292,171 435,604 1.983% 1.992% 1.852% 4.137% 9.647% 0.441%MI 2,996 2,944 52 6,681,711 1,889,380 4,792,331 15.621% 15.659% 13.462% 13.198% 23.736% 9.044%MN 1,459 1,432 27 3,959,159 2,725,622 1,233,537 1.097% 1.047% 3.704% 3.666% 5.272% 0.118%MO 1,421 1,344 77 3,006,743 1,692,282 1,314,461 2.111% 2.158% 1.299% 2.557% 3.785% 0.976%MT 843 784 59 757,031 364,632 392,399 1.423% 1.276% 3.390% 13.913% 20.319% 7.961%NC 2,283 2,144 139 6,973,518 1,708,352 5,265,166 6.351% 5.737% 15.827% 20.315% 9.757% 23.741%ND 217 190 27 563,069 257,844 305,225 0.922% 1.053% 0.000% 0.051% 0.111% 0.000%NE 731 720 11 1,449,290 672,810 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,216 1,175 41 942,517 392,718 549,799 2.385% 2.383% 2.439% 1.818% 1.499% 2.046%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 7.205% 6.806% 21.622% 27.478% 11.501% 36.127%NM 724 685 39 1,667,433 1,400,885 266,548 19.475% 19.562% 17.949% 52.338% 53.086% 48.406%NV 325 305 20 970,653 280,854 689,799 3.692% 3.607% 5.000% 7.279% 5.039% 8.191%NY 1,567 1,327 240 11,199,594 1,220,151 9,979,443 1.276% 1.055% 2.500% 0.326% 0.701% 0.280%OH 1,917 1,792 125 10,218,949 3,124,012 7,094,937 2.295% 2.344% 1.600% 2.425% 0.714% 3.179%OK 182 166 16 679,606 268,651 410,955 1.099% 1.205% 0.000% 0.795% 2.010% 0.000%OR 732 610 122 2,776,564 486,818 2,289,746 0.956% 0.984% 0.820% 0.063% 0.188% 0.036%RI 143 134 9 913,584 173,606 739,978 4.895% 2.985% 33.333% 18.447% 26.548% 16.547%SC 823 758 65 3,468,333 809,806 2,658,527 15.796% 15.831% 15.385% 14.657% 21.843% 12.468%SD 235 224 11 328,972 237,011 91,961 3.404% 3.571% 0.000% 3.988% 5.535% 0.000%TN 350 161 189 5,683,572 1,460,816 4,222,756 2.857% 0.621% 4.762% 15.139% 2.791% 19.411%TX 4,888 4,547 341 25,060,220 9,275,719 15,784,501 0.818% 0.682% 2.639% 4.407% 0.431% 6.743%UT 507 457 50 2,543,652 1,686,017 857,635 3.156% 2.845% 6.000% 13.432% 0.865% 38.137%VA 1,582 1,414 168 4,803,450 634,384 4,169,066 0.506% 0.495% 0.595% 0.129% 0.574% 0.061%VT 598 556 42 490,389 226,621 263,768 2.341% 2.518% 0.000% 0.568% 1.230% 0.000%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 14.536% 14.531% 15.000% 18.504% 26.390% 7.538%WV 451 290 161 1,415,477 234,687 1,180,790 5.322% 5.517% 4.969% 1.922% 1.475% 2.010%WY 304 255 49 446,184 129,168 317,016 8.553% 8.627% 8.163% 9.337% 6.561% 10.468%Total 48,920 44,928 3,992 229,685,370 85,335,776 144,349,594 5.605% 5.382% 8.116% 16.943% 14.395% 18.449%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A12c. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 6 6 0 0.571% 0.599% 0.000% 3,636 3,636 0 0.059% 0.130% 0.000%CA 19 14 5 0.498% 0.425% 0.956% 150,119 43,716 106,403 0.414% 0.326% 0.466%CO 1 0 1 0.119% 0.000% 0.452% 6,000 0 6,000 0.120% 0.000% 0.134%CT 4 3 1 0.342% 0.265% 2.564% 23,163 1,183 21,980 0.853% 0.309% 0.942%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 1 0 0.063% 0.068% 0.000% 163,688 163,688 0 2.260% 12.123% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 1 1 0 0.104% 0.107% 0.000% 510 510 0 0.020% 0.037% 0.000%ID 2 2 0 0.223% 0.236% 0.000% 46,830 46,830 0 4.465% 5.811% 0.000%IL 44 42 2 2.955% 3.030% 1.942% 231,041 127,561 103,480 2.520% 4.298% 1.669%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 886,428 0 886,428 19.260% 0.000% 20.970%MA 2 1 1 0.296% 0.180% 0.847% 43,585 85 43,500 0.511% 0.005% 0.639%MD 2 2 0 0.193% 0.206% 0.000% 260 260 0 0.005% 0.025% 0.000%ME 1 1 0 0.124% 0.133% 0.000% 15,000 15,000 0 2.061% 5.134% 0.000%MI 2 2 0 0.067% 0.068% 0.000% 215 215 0 0.003% 0.011% 0.000%MN 1 1 0 0.069% 0.070% 0.000% 753 753 0 0.019% 0.028% 0.000%MO 4 4 0 0.281% 0.298% 0.000% 7,998 7,998 0 0.266% 0.473% 0.000%MT 1 1 0 0.119% 0.128% 0.000% 25 25 0 0.003% 0.007% 0.000%NC 5 4 1 0.219% 0.187% 0.719% 724,060 1,114 722,946 10.383% 0.065% 13.731%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 7 7 0 0.576% 0.596% 0.000% 2,378 2,378 0 0.252% 0.606% 0.000%NJ 9 8 1 0.655% 0.598% 2.703% 78,418 67,449 10,969 1.010% 2.474% 0.218%NM 6 6 0 0.829% 0.876% 0.000% 3,313 3,313 0 0.199% 0.236% 0.000%NV 2 2 0 0.615% 0.656% 0.000% 4,243 4,243 0 0.437% 1.511% 0.000%NY 1 1 0 0.064% 0.075% 0.000% 50 50 0 0.000% 0.004% 0.000%OH 4 4 0 0.209% 0.223% 0.000% 1,675 1,675 0 0.016% 0.054% 0.000%OK 1 1 0 0.549% 0.602% 0.000% 500 500 0 0.074% 0.186% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 2 2 0 0.041% 0.044% 0.000% 645 645 0 0.003% 0.007% 0.000%UT 2 2 0 0.394% 0.438% 0.000% 3,450 3,450 0 0.136% 0.205% 0.000%VA 1 1 0 0.063% 0.071% 0.000% 620 620 0 0.013% 0.098% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.055% 0.055% 0.000% 86 86 0 0.002% 0.004% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 1 1 0 0.329% 0.392% 0.000% 380 380 0 0.085% 0.294% 0.000%Total 134 121 13 0.274% 0.269% 0.326% 2,399,069 497,363 1,901,706 1.045% 0.583% 1.317%

Percent of Population Served 

with At Least One Detection 

> 0.005 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.005 mg/L

Percent of Systems 

with At Least One Detection 

> 0.005 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.005 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A12d. Cadmium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 0 1 0.202% 0.000% 0.980% 50 0 50 0.009% 0.000% 0.015%AL 14 6 8 3.977% 2.151% 10.959% 449,712 24,863 424,849 9.566% 1.699% 13.121%AR 1 1 0 0.221% 0.262% 0.000% 3,868 3,868 0 0.158% 0.425% 0.000%AZ 11 9 2 1.048% 0.898% 4.167% 443,422 18,922 424,500 7.196% 0.678% 12.594%CA 63 51 12 1.650% 1.547% 2.294% 1,203,652 480,044 723,608 3.321% 3.579% 3.170%CO 4 0 4 0.477% 0.000% 1.810% 97,245 0 97,245 1.945% 0.000% 2.178%CT 14 13 1 1.197% 1.149% 2.564% 25,314 3,334 21,980 0.932% 0.872% 0.942%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 4 4 0 0.300% 0.306% 0.000% 84,760 84,760 0 0.491% 0.565% 0.000%GA 2 2 0 0.126% 0.135% 0.000% 164,565 164,565 0 2.272% 12.188% 0.000%HI 1 1 0 0.935% 1.053% 0.000% 29,183 29,183 0 2.238% 2.336% 0.000%IA 6 6 0 0.621% 0.643% 0.000% 1,999 1,999 0 0.080% 0.144% 0.000%ID 4 4 0 0.446% 0.472% 0.000% 62,279 62,279 0 5.938% 7.728% 0.000%IL 142 133 9 9.537% 9.596% 8.738% 711,278 486,439 224,839 7.758% 16.389% 3.626%IN 45 45 0 2.773% 2.859% 0.000% 97,122 97,122 0 1.950% 3.708% 0.000%KY 7 4 3 2.893% 4.301% 2.013% 920,164 19,201 900,963 19.993% 5.114% 21.314%MA 6 4 2 0.889% 0.718% 1.695% 68,639 475 68,164 0.805% 0.028% 1.001%MD 9 7 2 0.867% 0.722% 2.941% 47,595 16,096 31,499 0.948% 1.571% 0.788%ME 3 3 0 0.372% 0.398% 0.000% 15,435 15,435 0 2.121% 5.283% 0.000%MI 5 5 0 0.167% 0.170% 0.000% 511 511 0 0.008% 0.027% 0.000%MN 3 3 0 0.206% 0.209% 0.000% 1,743 1,743 0 0.044% 0.064% 0.000%MO 7 7 0 0.493% 0.521% 0.000% 11,268 11,268 0 0.375% 0.666% 0.000%MT 2 2 0 0.237% 0.255% 0.000% 310 310 0 0.041% 0.085% 0.000%NC 12 10 2 0.526% 0.466% 1.439% 823,916 22,763 801,153 11.815% 1.332% 15.216%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 8 8 0 0.658% 0.681% 0.000% 2,431 2,431 0 0.258% 0.619% 0.000%NJ 25 23 2 1.820% 1.720% 5.405% 111,683 84,885 26,798 1.439% 3.113% 0.532%NM 13 12 1 1.796% 1.752% 2.564% 77,071 4,370 72,701 4.622% 0.312% 27.275%NV 3 3 0 0.923% 0.984% 0.000% 4,523 4,523 0 0.466% 1.610% 0.000%NY 5 4 1 0.319% 0.301% 0.417% 2,499 2,167 332 0.022% 0.178% 0.003%OH 6 6 0 0.313% 0.335% 0.000% 1,853 1,853 0 0.018% 0.059% 0.000%OK 2 2 0 1.099% 1.205% 0.000% 5,400 5,400 0 0.795% 2.010% 0.000%OR 1 1 0 0.137% 0.164% 0.000% 125 125 0 0.005% 0.026% 0.000%RI 4 2 2 2.797% 1.493% 22.222% 160,952 41,689 119,263 17.618% 24.014% 16.117%SC 3 2 1 0.365% 0.264% 1.538% 8,726 5,737 2,989 0.252% 0.708% 0.112%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 0 1 0.286% 0.000% 0.529% 25,379 0 25,379 0.447% 0.000% 0.601%TX 9 8 1 0.184% 0.176% 0.293% 2,321 2,189 132 0.009% 0.024% 0.001%UT 6 4 2 1.183% 0.875% 4.000% 324,475 3,925 320,550 12.756% 0.233% 37.376%VA 2 2 0 0.126% 0.141% 0.000% 746 746 0 0.016% 0.118% 0.000%VT 1 1 0 0.167% 0.180% 0.000% 300 300 0 0.061% 0.132% 0.000%WI 5 5 0 0.274% 0.277% 0.000% 471 471 0 0.012% 0.020% 0.000%WV 1 0 1 0.222% 0.000% 0.621% 1,800 0 1,800 0.127% 0.000% 0.152%WY 5 4 1 1.645% 1.569% 2.041% 4,858 4,780 78 1.089% 3.701% 0.025%Total 466 407 59 0.953% 0.906% 1.478% 5,999,643 1,710,771 4,288,872 2.612% 2.005% 2.971%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A13. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 40 μg/L 28,289 0 0.000% 61,793,025 0 0.000%	
 28,289 0 0.000% 61,793,025 0 0.000%

	
 28,289 0 0.000% 61,793,025 0 0.000%

> 0.9 μg/L 28,289 7 0.025% 61,793,025 71,762 0.116%

> 40 μg/L 2,808 0 0.000% 106,180,317 0 0.000%	
 2,808 0 0.000% 106,180,317 0 0.000%

	
 2,808 1 0.036% 106,180,317 3,186 0.003%

> 0.9 μg/L 2,808 2 0.071% 106,180,317 257,648 0.243%

> 40 μg/L 31,097 0 0.000% 167,973,342 0 0.000%	
 31,097 0 0.000% 167,973,342 0 0.000%

	
 31,097 1 0.003% 167,973,342 3,186 0.002%

> 0.9 μg/L 31,097 9 0.029% 167,973,342 329,410 0.196%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A13a. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 32 14 18 0.000% 0.000% 0.000%AL 503 374 129 0.000% 0.000% 0.000%AR 1,544 1,318 226 0.000% 0.000% 0.000%AZ 6,354 4,914 1,440 0.094% 0.102% 0.069% 0.5 0.5 0.5 0.5 0.5 0.5 2 2 0.5 2 2 0.5CA 11,955 6,800 5,155 0.000% 0.000% 0.000%CO 2,390 1,718 672 0.000% 0.000% 0.000%CT 1,324 1,013 311 0.000% 0.000% 0.000%DE 1,248 1,218 30 0.481% 0.493% 0.000% 0.54 0.54 0.54 0.54 0.54 0.54 0.54 0.54FL 2,357 2,292 65 0.552% 0.567% 0.000% 0.23 0.23 0.5 0.5 1 1 1 1GA 1,428 1,355 73 0.000% 0.000% 0.000%HI 1,694 1,646 48 0.000% 0.000% 0.000%IA 48 31 17 0.000% 0.000% 0.000%ID 1,171 959 212 0.000% 0.000% 0.000%IL 3,815 3,411 404 0.000% 0.000% 0.000%IN 2,243 2,083 160 0.000% 0.000% 0.000%KY 1,764 444 1,320 0.454% 0.000% 0.606% 0.7 0.7 0.9 0.9 2.5 2.5 2.5 2.5MA 2,909 2,145 764 0.103% 0.093% 0.131% 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9MD 2,362 1,635 727 0.212% 0.000% 0.688% 0.9 0.9 0.9 0.9 0.9 0.9 0.9 0.9ME 357 300 57 0.000% 0.000% 0.000%MI 6,596 6,329 267 0.000% 0.000% 0.000%MN 4,577 4,443 134 0.000% 0.000% 0.000%MO 4,611 4,041 570 0.022% 0.025% 0.000% 1.05 1.05 1.05 1.05 1.05 1.05 1.05 1.05MT 2,850 2,582 268 0.000% 0.000% 0.000%NC 12,779 11,736 1,043 0.000% 0.000% 0.000%ND 59 41 18 0.000% 0.000% 0.000%NE 2,345 2,279 66 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 158 145 13 0.000% 0.000% 0.000%NM 4,258 4,009 249 0.023% 0.025% 0.000% 3 3 3 3 3 3 3 3NV 1,531 1,140 391 0.000% 0.000% 0.000%NY 2,879 2,168 711 0.069% 0.092% 0.000% 0.5 0.5 0.75 0.75 1 1 1 1OH 531 381 150 0.000% 0.000% 0.000%OK 5 5 0 0.000% 0.000% 0.000%OR 2,056 1,573 483 0.000% 0.000% 0.000%RI 471 316 155 0.000% 0.000% 0.000%SC 2,996 2,623 373 0.033% 0.038% 0.000% 1.03 1.03 1.03 1.03 1.03 1.03 1.03 1.03SD 898 787 111 0.000% 0.000% 0.000%TN 155 31 124 0.000% 0.000% 0.000%TX 829 706 123 0.000% 0.000% 0.000%UT 7,110 5,922 1,188 0.000% 0.000% 0.000%VA 416 154 262 0.000% 0.000% 0.000%VT 1,287 1,097 190 0.311% 0.365% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5WI 3,162 3,070 92 0.000% 0.000% 0.000%WV 640 334 306 1.719% 2.096% 1.307% 0.5 0.54 0.5 0.73 0.54 0.73 0.73 0.73 8 8 0.73 8WY 1,252 939 313 0.000% 0.000% 0.000%Total 114,142 94,395 19,747 0.053% 0.044% 0.096% 0.23 0.23 0.5 0.54 0.54 0.9 1.05 1 2.5 8 3 8

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A13b. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 8 6 2 22,575 13,611 8,964 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 171 126 45 2,702,037 589,449 2,112,588 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 912 864 48 6,035,739 2,665,148 3,370,591 0.329% 0.231% 2.083% 5.892% 2.088% 8.901%CA 1,372 1,104 268 32,726,875 11,163,398 21,563,477 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CO 797 580 217 4,978,181 511,547 4,466,634 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 653 616 37 2,588,367 261,100 2,327,267 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 238 235 3 650,290 368,890 281,400 2.521% 2.553% 0.000% 1.032% 1.819% 0.000%FL 1,309 1,288 21 16,785,698 14,546,522 2,239,176 0.611% 0.621% 0.000% 18.378% 21.207% 0.000%GA 296 283 13 994,603 305,252 689,351 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 110 98 12 1,300,849 1,246,221 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 4 3 1 162,197 27,580 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 489 463 26 856,983 639,201 217,782 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,365 1,261 104 9,183,137 2,982,740 6,200,397 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,403 1,359 44 4,870,706 2,550,970 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 242 93 149 4,602,489 375,460 4,227,029 2.479% 0.000% 4.027% 7.771% 0.000% 8.461%MA 644 527 117 8,509,572 1,707,190 6,802,382 0.466% 0.380% 0.855% 0.475% 1.833% 0.134%MD 856 790 66 4,901,793 906,003 3,995,790 0.117% 0.000% 1.515% 34.885% 0.000% 42.795%ME 208 185 23 471,954 108,050 363,904 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,926 2,865 61 7,226,429 2,046,573 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,282 1,253 29 3,931,466 2,681,825 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,461 1,385 76 2,643,059 1,698,598 944,461 0.068% 0.072% 0.000% 0.023% 0.035% 0.000%MT 812 752 60 753,305 360,636 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ND 28 22 6 47,665 40,636 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 712 701 11 1,453,178 676,698 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 128 118 10 1,906,326 343,608 1,562,718 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 696 660 36 1,663,162 1,400,264 262,898 0.144% 0.152% 0.000% 0.013% 0.016% 0.000%NV 291 270 21 960,557 270,666 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,345 1,114 231 4,923,641 980,364 3,943,277 0.149% 0.180% 0.000% 0.066% 0.332% 0.000%OH 269 190 79 6,465,862 483,522 5,982,340 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OK 3 3 0 905 905 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OR 1,084 934 150 2,937,354 572,604 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 72 63 9 894,778 154,800 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 778 719 59 3,428,914 802,131 2,626,783 0.129% 0.139% 0.000% 0.002% 0.010% 0.000%SD 259 238 21 621,074 261,903 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 63 16 47 1,748,866 175,699 1,573,167 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 669 606 63 2,803,106 435,220 2,367,886 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,671 1,667,485 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 174 65 109 2,312,591 26,001 2,286,590 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 438 404 34 432,235 180,711 251,524 0.913% 0.990% 0.000% 0.148% 0.354% 0.000%WI 1,405 1,385 20 3,883,163 2,191,419 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 339 194 145 1,360,534 203,368 1,157,166 2.655% 3.608% 1.379% 0.652% 0.643% 0.653%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 31,097 28,289 2,808 167,973,342 61,793,025 106,180,317 0.145% 0.120% 0.392% 3.315% 5.154% 2.246%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A13c. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 40 μg/L

State

Number of Systems 

with At Least One Detection 

> 40 μg/L

Percent of Systems 

with At Least One Detection 

> 40 μg/L

Population Served by Systems 

with At Least One Detection 

> 40 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A13d. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A13e. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 0 1 0.295% 0.000% 0.690% 3,186 0 3,186 0.234% 0.000% 0.275%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 0 1 0.003% 0.000% 0.036% 3,186 0 3,186 0.002% 0.000% 0.003%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A13f. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.110% 0.116% 0.000% 5,005 5,005 0 0.083% 0.188% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 2 2 0 0.153% 0.155% 0.000% 62,906 62,906 0 0.375% 0.432% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 254,462 0 254,462 5.529% 0.000% 6.020%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.068% 0.072% 0.000% 603 603 0 0.023% 0.035% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 1 1 0 0.144% 0.152% 0.000% 220 220 0 0.013% 0.016% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.074% 0.090% 0.000% 2,950 2,950 0 0.060% 0.301% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 1 0 0.129% 0.139% 0.000% 78 78 0 0.002% 0.010% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 0 1 0.295% 0.000% 0.690% 3,186 0 3,186 0.234% 0.000% 0.275%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 9 7 2 0.029% 0.025% 0.071% 329,410 71,762 257,648 0.196% 0.116% 0.243%

Percent of Population Served 

with At Least One Detection 

> 0.9 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.9 μg/L

Percent of Systems 

with At Least One Detection 

> 0.9 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.9 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A14. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 46,190 49 0.106% 86,397,574 146,334 0.169%

	
 46,190 81 0.175% 86,397,574 313,180 0.362%

	
 46,190 179 0.388% 86,397,574 1,010,901 1.170%

> 0.5 μg/L 46,190 312 0.675% 86,397,574 1,813,677 2.099%

> 5 μg/L 4,256 8 0.188% 140,537,213 4,821,230 3.431%

	
 4,256 25 0.587% 140,537,213 5,174,513 3.682%

	
 4,256 82 1.927% 140,537,213 7,071,752 5.032%

> 0.5 μg/L 4,256 147 3.454% 140,537,213 12,609,728 8.973%

> 5 μg/L 50,446 57 0.113% 226,934,787 4,967,564 2.189%

	
 50,446 106 0.210% 226,934,787 5,487,693 2.418%

	
 50,446 261 0.517% 226,934,787 8,082,653 3.562%

> 0.5 μg/L 50,446 459 0.910% 226,934,787 14,423,405 6.356%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A14a. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,108 1,970 1,138 0.161% 0.152% 0.176% 0.23 0.23 0.91 0.62 0.6 1.105 1.3 0.62 1.3 1.3 0.62 1.3AL 834 601 233 2.398% 0.832% 6.438% 0.54 0.54 0.6 1.245 1.71 1.2 2.025 5.74 1.5 5.74 5.74 1.6AR 2,394 1,926 468 2.966% 2.908% 3.205% 0.15 0.15 0.17 0.68 0.675 0.71 6 7.4 1.36 16.3 16.3 2.04AZ 11,687 9,519 2,168 0.086% 0.053% 0.231% 0.5 0.6 0.5 0.8 1.1 0.5 19.25 37 1.1 37 37 1.1CA 98,417 51,662 46,755 3.621% 3.004% 4.303% 0.2 0.2 0.5 1.3 1.5 1.1 4.3 3.4 6 27 14.4 27CO 2,875 2,135 740 0.348% 0.234% 0.676% 0.2 0.2 0.2 0.2 0.2 0.3 0.45 0.2 0.5 0.5 0.2 0.5CT 6,938 6,047 891 0.101% 0.066% 0.337% 0.5 1.9 0.5 1.9 2.5 0.6 2.85 2.85 0.6 2.85 2.85 0.6DE 1,047 1,017 30 0.000% 0.000% 0.000%FL 4,178 4,108 70 0.646% 0.657% 0.000% 0.09 0.09 0.47 0.47 1.1 1.1 1.2 1.2GA 7,175 6,348 827 0.251% 0.205% 0.605% 0.5 0.5 0.51 0.77 0.68 0.83 0.95 0.95 0.94 1.2 1.2 0.94HI 1,791 1,688 103 6.142% 5.746% 12.621% 0.5 0.5 0.5 0.5 0.5 0.5 0.7 0.7 0.52 1.4 1.4 0.6IA 1,819 1,695 124 0.935% 0.885% 1.613% 0.1 0.1 0.6 0.6 0.5 1.15 8.7 8.7 1.7 300 300 1.7ID 3,765 3,304 461 0.452% 0.484% 0.217% 0.6 1.8 0.6 3 3.05 0.6 3.7 3.7 0.6 3.8 3.8 0.6IL 7,100 6,492 608 0.507% 0.447% 1.151% 0.5 0.5 0.5 0.715 0.73 0.7 1.7 1 2.49 11 11 2.49IN 4,621 4,311 310 0.130% 0.116% 0.323% 0.5 0.5 1.4 1.05 1 1.4 8.3 8.3 1.4 8.3 8.3 1.4KY 3,322 1,126 2,196 1.475% 0.178% 2.140% 0.003 0.4 0.003 0.4 1.3 0.3 2 2.2 2 3 2.2 3MA 16,249 12,259 3,990 0.043% 0.041% 0.050% 0.2 0.2 0.54 0.7 0.7 0.77 19.3 19.3 1 19.3 19.3 1MD 6,773 5,511 1,262 0.325% 0.236% 0.713% 0.1 0.5 0.1 0.75 0.7 0.8 2.2 2.2 3.6 3.6 3.3 3.6ME 3,698 3,383 315 0.162% 0.177% 0.000% 0.5 0.5 3.35 3.35 10 10 10 10MI 10,754 9,744 1,010 0.130% 0.041% 0.990% 0.4 0.4 0.4 0.6 0.95 0.6 1.7 3.1 1.35 3.1 3.1 1.7MN 8,585 7,336 1,249 1.142% 0.913% 2.482% 0.2 0.2 0.2 0.3 0.4 0.3 0.9 1 0.6 2.9 2.9 0.9MO 7,543 6,694 849 0.186% 0.105% 0.824% 0.5 0.5 0.5 0.8 1.2 0.6 1.7 2.6 1.7 2.6 2.6 1.7MT 4,495 3,956 539 0.111% 0.101% 0.186% 0.99 0.99 2.2 1.25 1.135 2.2 2.2 2.14 2.2 2.2 2.14 2.2NC 19,065 17,486 1,579 0.257% 0.223% 0.633% 0.5 0.5 0.5 0.8 0.8 0.85 2.6 2.7 2.33 5.2 5.2 2.6ND 534 407 127 0.187% 0.000% 0.787% 1.38 1.38 1.38 1.38 1.38 1.38 1.38 1.38NE 6,842 6,265 577 1.725% 1.868% 0.173% 0.21 0.21 0.65 1 1 0.65 3.9 3.9 0.65 38.9 38.9 0.65NH 9,582 9,104 478 0.031% 0.022% 0.209% 0.5 0.5 3.3 3.3 2.45 3.3 4.4 4.4 3.3 4.4 4.4 3.3NJ 20,356 18,570 1,786 0.447% 0.458% 0.336% 0.1 0.1 0.1 0.64 0.68 0.445 4.77 5.94 1.2 28.62 28.62 1.2NM 6,572 6,096 476 0.228% 0.213% 0.420% 0.2 0.57 0.2 0.8 0.8 2.4 4.28 4.1 4.6 4.6 4.28 4.6NV 3,211 2,579 632 0.280% 0.310% 0.158% 0.52 0.52 1.5 1.5 1.5 1.5 8.51 8.51 1.5 8.51 8.51 1.5NY 7,073 5,406 1,667 0.240% 0.259% 0.180% 0.5 0.5 0.5 0.65 0.68 0.5 1.4 1.4 0.5 10.7 10.7 0.5OH 8,845 7,686 1,159 0.215% 0.156% 0.604% 0.26 0.5 0.26 0.9 0.835 0.9 6.9 6.9 2.5 11.5 11.5 2.5OK 5,635 4,200 1,435 0.497% 0.548% 0.348% 0.22 0.4 0.22 1.04 1.1 0.53 10.3 10.3 1.3 33.6 33.6 1.3OR 2,324 1,682 642 0.043% 0.059% 0.000% 11.3 11.3 11.3 11.3 11.3 11.3 11.3 11.3RI 1,959 1,591 368 0.255% 0.126% 0.815% 0.7 3.1 0.7 6.8 4.95 12 12 6.8 12 12 6.8 12SC 4,342 3,803 539 0.322% 0.210% 1.113% 0.51 0.51 0.6 1.63 1.965 1.63 8.09 9.17 3.1 9.17 9.17 3.1SD 889 855 34 0.000% 0.000% 0.000%TN 2,945 1,165 1,780 0.374% 0.343% 0.393% 0.1 0.67 0.1 1.4 1.65 0.6 3.2 2.7 3.3 3.3 2.7 3.3TX 34,154 27,046 7,108 0.351% 0.311% 0.506% 0.5 0.5 0.5 0.9 0.9 0.815 1.865 1.8 1.96 8.4 8.4 2.55UT 8,988 7,557 1,431 0.022% 0.026% 0.000% 0.7 0.7 0.9 0.9 1.1 1.1 1.1 1.1VA 4,930 4,057 873 0.081% 0.074% 0.115% 0.6 0.6 0.7 0.92 1.14 0.7 44 44 0.7 44 44 0.7VT 4,349 3,956 393 0.207% 0.177% 0.509% 0.4 0.4 0.6 1.6 5 1.1 18.2 18.2 1.6 18.2 18.2 1.6WI 11,294 11,169 125 0.159% 0.143% 1.600% 0.03 0.03 0.1 0.41 0.465 0.145 4.7 4.7 0.19 7.6 7.6 0.19WV 1,146 444 702 2.182% 3.153% 1.567% 0.24 0.24 0.31 0.5 0.5 0.5 4.6 1 4.6 15 15 6.8WY 1,661 1,156 505 0.843% 1.038% 0.396% 0.1 0.1 0.3 0.765 0.765 0.535 1.41 1.41 0.77 14 14 0.77Total 385,864 295,112 90,752 1.220% 0.815% 2.534% 0.003 0.03 0.003 1.1 1.24 1 3.9 3.5 5.04 300 300 27

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A14b. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.645% 0.633% 0.685% 7.909% 20.598% 0.009%AL 263 202 61 4,218,278 1,123,190 3,095,088 2.662% 2.475% 3.279% 6.997% 2.536% 8.616%AR 454 382 72 2,453,348 910,322 1,543,026 10.793% 9.686% 16.667% 7.868% 9.050% 7.170%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.567% 0.297% 6.250% 7.926% 0.267% 14.280%CA 3,655 3,138 517 35,828,727 13,516,266 22,312,461 1.450% 0.860% 5.029% 18.203% 6.351% 25.383%CO 828 607 221 4,999,966 532,332 4,467,634 0.966% 0.659% 1.810% 35.089% 0.341% 39.229%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.249% 0.171% 2.564% 1.416% 0.728% 1.531%DE 318 315 3 698,987 417,587 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,513 1,487 26 17,495,771 15,249,729 2,246,042 1.058% 1.076% 0.000% 1.819% 2.087% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.439% 0.234% 3.448% 0.865% 0.495% 0.965%HI 106 94 12 1,293,745 1,239,117 54,628 6.604% 3.191% 33.333% 3.959% 2.984% 26.080%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 1.042% 0.880% 6.061% 3.427% 2.646% 4.436%ID 935 878 57 1,093,666 837,604 256,062 0.321% 0.228% 1.754% 17.711% 0.919% 72.639%IL 1,430 1,326 104 9,217,990 3,017,593 6,200,397 1.818% 1.508% 5.769% 2.718% 2.553% 2.799%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.339% 0.280% 2.273% 0.047% 0.085% 0.004%KY 241 92 149 4,602,392 375,363 4,227,029 14.523% 2.174% 22.148% 41.009% 2.265% 44.450%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.836% 0.667% 1.695% 2.076% 3.911% 1.604%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 1.518% 0.913% 10.294% 37.537% 1.981% 46.655%ME 810 757 53 728,347 292,773 435,574 0.741% 0.793% 0.000% 0.223% 0.555% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.370% 0.137% 11.475% 2.411% 2.940% 2.209%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 3.034% 2.448% 33.333% 31.361% 6.370% 91.571%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.917% 0.522% 7.792% 5.219% 5.978% 4.244%MT 848 788 60 757,949 365,280 392,669 0.472% 0.381% 1.667% 5.161% 0.175% 9.799%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 1.394% 1.032% 7.194% 4.948% 5.058% 4.912%ND 208 181 27 562,292 257,067 305,225 0.481% 0.000% 3.704% 0.030% 0.000% 0.054%NE 771 760 11 1,462,181 685,701 776,480 3.243% 3.158% 9.091% 37.521% 5.317% 65.960%NH 1,258 1,217 41 948,788 398,989 549,799 0.238% 0.164% 2.439% 1.282% 0.041% 2.183%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 2.289% 1.984% 13.514% 25.374% 9.791% 33.767%NM 726 687 39 1,698,755 1,432,207 266,548 1.653% 1.456% 5.128% 5.180% 6.052% 0.492%NV 338 317 21 973,592 283,701 689,891 2.071% 1.893% 4.762% 1.880% 3.527% 1.203%NY 1,522 1,287 235 4,889,304 1,042,687 3,846,617 0.657% 0.544% 1.277% 0.489% 2.087% 0.056%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.926% 0.605% 5.600% 4.948% 2.492% 6.033%OK 730 518 212 3,123,687 664,833 2,458,854 2.329% 2.317% 2.358% 1.710% 2.032% 1.623%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.091% 0.106% 0.000% 0.110% 0.560% 0.000%RI 145 136 9 913,884 173,906 739,978 2.069% 0.735% 22.222% 13.088% 0.345% 16.083%SC 819 757 62 3,356,831 732,879 2,623,952 1.099% 0.925% 3.226% 1.076% 2.187% 0.765%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 2.564% 1.235% 3.704% 5.568% 0.453% 7.340%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 1.414% 0.998% 7.018% 7.728% 2.334% 10.899%UT 500 454 46 2,553,197 1,698,877 854,320 0.200% 0.220% 0.000% 3.482% 5.233% 0.000%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 0.250% 0.210% 0.585% 0.093% 0.151% 0.085%VT 603 560 43 491,035 227,067 263,968 1.327% 1.250% 2.326% 0.932% 0.175% 1.584%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.841% 0.737% 10.000% 4.268% 2.031% 7.373%WV 403 243 160 1,416,020 237,670 1,178,350 5.459% 5.761% 5.000% 6.587% 1.659% 7.581%WY 304 256 48 446,177 129,229 316,948 1.645% 1.172% 4.167% 0.243% 0.412% 0.174%Total 50,446 46,190 4,256 226,934,787 86,397,574 140,537,213 1.289% 0.935% 5.122% 9.831% 3.419% 13.773%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A14c. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 1 0 0.380% 0.495% 0.000% 14,604 14,604 0 0.346% 1.300% 0.000%AR 5 5 0 1.101% 1.309% 0.000% 7,904 7,904 0 0.322% 0.868% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 1,808 1,808 0 0.029% 0.065% 0.000%CA 13 7 6 0.356% 0.223% 1.161% 4,866,041 95,742 4,770,299 13.581% 0.708% 21.380%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.189% 0.196% 0.000% 158 158 0 0.006% 0.011% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 400 400 0 0.004% 0.013% 0.000%IN 1 1 0 0.068% 0.070% 0.000% 262 262 0 0.005% 0.010% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 1 1 0 0.139% 0.167% 0.000% 75 75 0 0.001% 0.004% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 3 3 0 0.370% 0.396% 0.000% 676 676 0 0.093% 0.231% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 85 85 0 0.001% 0.005% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 3 3 0 0.389% 0.395% 0.000% 1,620 1,620 0 0.111% 0.236% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 4 4 0 0.286% 0.294% 0.000% 6,101 6,101 0 0.079% 0.225% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 1 0 0.296% 0.315% 0.000% 600 600 0 0.062% 0.211% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.162% 0.000%OH 2 2 0 0.103% 0.110% 0.000% 360 360 0 0.004% 0.011% 0.000%OK 3 3 0 0.411% 0.579% 0.000% 8,250 8,250 0 0.264% 1.241% 0.000%OR 1 1 0 0.091% 0.106% 0.000% 3,220 3,220 0 0.110% 0.560% 0.000%RI 2 1 1 1.379% 0.735% 11.111% 51,350 600 50,750 5.619% 0.345% 6.858%SC 2 2 0 0.244% 0.264% 0.000% 1,664 1,664 0 0.050% 0.227% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 42 42 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.070% 0.000% 60 60 0 0.001% 0.010% 0.000%VT 3 3 0 0.498% 0.536% 0.000% 194 194 0 0.040% 0.085% 0.000%WI 1 1 0 0.056% 0.057% 0.000% 105 105 0 0.003% 0.004% 0.000%WV 2 1 1 0.496% 0.412% 0.625% 255 74 181 0.018% 0.031% 0.015%WY 1 1 0 0.329% 0.391% 0.000% 45 45 0 0.010% 0.035% 0.000%Total 57 49 8 0.113% 0.106% 0.188% 4,967,564 146,334 4,821,230 2.189% 0.169% 3.431%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A14d. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 1 0 0.380% 0.495% 0.000% 14,604 14,604 0 0.346% 1.300% 0.000%AR 6 6 0 1.322% 1.571% 0.000% 8,365 8,365 0 0.341% 0.919% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 1,808 1,808 0 0.029% 0.065% 0.000%CA 20 9 11 0.547% 0.287% 2.128% 5,084,536 125,979 4,958,557 14.191% 0.932% 22.223%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 2,834 2,834 0 0.104% 0.728% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.189% 0.196% 0.000% 158 158 0 0.006% 0.011% 0.000%ID 1 1 0 0.107% 0.114% 0.000% 200 200 0 0.018% 0.024% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 400 400 0 0.004% 0.013% 0.000%IN 1 1 0 0.068% 0.070% 0.000% 262 262 0 0.005% 0.010% 0.000%KY 2 0 2 0.830% 0.000% 1.342% 53,226 0 53,226 1.156% 0.000% 1.259%MA 2 2 0 0.279% 0.333% 0.000% 7,007 7,007 0 0.082% 0.400% 0.000%MD 2 1 1 0.190% 0.101% 1.471% 13,952 296 13,656 0.278% 0.029% 0.342%ME 3 3 0 0.370% 0.396% 0.000% 676 676 0 0.093% 0.231% 0.000%MI 1 1 0 0.034% 0.034% 0.000% 45 45 0 0.001% 0.002% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 100 100 0 0.002% 0.003% 0.000%MO 1 1 0 0.071% 0.075% 0.000% 90 90 0 0.003% 0.005% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 5 4 1 0.211% 0.180% 0.719% 13,028 6,658 6,370 0.186% 0.384% 0.121%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 3 3 0 0.389% 0.395% 0.000% 1,620 1,620 0 0.111% 0.236% 0.000%NH 2 1 1 0.159% 0.082% 2.439% 12,123 123 12,000 1.278% 0.031% 2.183%NJ 5 5 0 0.358% 0.367% 0.000% 6,381 6,381 0 0.082% 0.235% 0.000%NM 5 4 1 0.689% 0.582% 2.564% 3,061 1,801 1,260 0.180% 0.126% 0.473%NV 1 1 0 0.296% 0.315% 0.000% 600 600 0 0.062% 0.211% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.162% 0.000%OH 3 2 1 0.154% 0.110% 0.800% 10,160 360 9,800 0.099% 0.011% 0.138%OK 4 4 0 0.548% 0.772% 0.000% 8,500 8,500 0 0.272% 1.279% 0.000%OR 1 1 0 0.091% 0.106% 0.000% 3,220 3,220 0 0.110% 0.560% 0.000%RI 2 1 1 1.379% 0.735% 11.111% 51,350 600 50,750 5.619% 0.345% 6.858%SC 5 4 1 0.611% 0.528% 1.613% 14,916 4,566 10,350 0.444% 0.623% 0.394%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 4 1 3 1.140% 0.617% 1.587% 40,657 5,294 35,363 0.715% 0.362% 0.837%TX 8 7 1 0.162% 0.152% 0.292% 118,115 95,115 23,000 0.470% 1.023% 0.145%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.070% 0.000% 60 60 0 0.001% 0.010% 0.000%VT 4 4 0 0.663% 0.714% 0.000% 239 239 0 0.049% 0.105% 0.000%WI 2 2 0 0.112% 0.113% 0.000% 13,415 13,415 0 0.332% 0.571% 0.000%WV 2 1 1 0.496% 0.412% 0.625% 255 74 181 0.018% 0.031% 0.015%WY 1 1 0 0.329% 0.391% 0.000% 45 45 0 0.010% 0.035% 0.000%Total 106 81 25 0.210% 0.175% 0.587% 5,487,693 313,180 5,174,513 2.418% 0.362% 3.682%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A14e. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 0 1 0.161% 0.000% 0.685% 34 0 34 0.006% 0.000% 0.009%AL 6 4 2 2.281% 1.980% 3.279% 289,341 22,680 266,661 6.859% 2.019% 8.616%AR 16 13 3 3.524% 3.403% 4.167% 57,851 35,581 22,270 2.358% 3.909% 1.443%AZ 4 3 1 0.378% 0.297% 2.083% 8,565 7,465 1,100 0.139% 0.267% 0.033%CA 37 17 20 1.012% 0.542% 3.868% 5,653,559 421,543 5,232,016 15.779% 3.119% 23.449%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 2,834 2,834 0 0.104% 0.728% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 3 3 0 0.198% 0.202% 0.000% 125 125 0 0.001% 0.001% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 450 450 0 0.006% 0.028% 0.000%HI 1 1 0 0.943% 1.064% 0.000% 650 650 0 0.050% 0.052% 0.000%IA 3 2 1 0.284% 0.196% 3.030% 30,476 158 30,318 1.198% 0.011% 2.735%ID 2 2 0 0.214% 0.228% 0.000% 7,700 7,700 0 0.704% 0.919% 0.000%IL 5 3 2 0.350% 0.226% 1.923% 150,874 6,335 144,539 1.637% 0.210% 2.331%IN 4 3 1 0.271% 0.210% 2.273% 2,259 2,162 97 0.046% 0.084% 0.004%KY 10 1 9 4.149% 1.087% 6.040% 237,356 42 237,314 5.157% 0.011% 5.614%MA 3 2 1 0.418% 0.333% 0.847% 77,214 7,007 70,207 0.902% 0.400% 1.031%MD 7 4 3 0.664% 0.406% 4.412% 133,055 8,732 124,323 2.649% 0.852% 3.110%ME 5 5 0 0.617% 0.661% 0.000% 1,411 1,411 0 0.194% 0.482% 0.000%MI 5 2 3 0.168% 0.069% 4.918% 56,421 83 56,338 0.788% 0.004% 1.088%MN 4 4 0 0.253% 0.258% 0.000% 21,419 21,419 0 0.503% 0.711% 0.000%MO 7 4 3 0.494% 0.299% 3.896% 107,971 92,630 15,341 3.594% 5.482% 1.167%MT 4 3 1 0.472% 0.381% 1.667% 39,118 641 38,477 5.161% 0.175% 9.799%NC 14 11 3 0.591% 0.494% 2.158% 55,698 36,538 19,160 0.796% 2.108% 0.364%ND 1 0 1 0.481% 0.000% 3.704% 166 0 166 0.030% 0.000% 0.054%NE 11 11 0 1.427% 1.447% 0.000% 5,986 5,986 0 0.409% 0.873% 0.000%NH 2 1 1 0.159% 0.082% 2.439% 12,123 123 12,000 1.278% 0.031% 2.183%NJ 9 8 1 0.644% 0.588% 2.703% 325,501 13,625 311,876 4.201% 0.502% 6.193%NM 6 5 1 0.826% 0.728% 2.564% 4,461 3,201 1,260 0.263% 0.224% 0.473%NV 5 4 1 1.479% 1.262% 4.762% 15,031 6,731 8,300 1.544% 2.373% 1.203%NY 3 3 0 0.197% 0.233% 0.000% 5,560 5,560 0 0.114% 0.533% 0.000%OH 9 6 3 0.463% 0.330% 2.400% 123,433 6,581 116,852 1.207% 0.210% 1.647%OK 8 7 1 1.096% 1.351% 0.472% 9,468 9,133 335 0.303% 1.374% 0.014%OR 1 1 0 0.091% 0.106% 0.000% 3,220 3,220 0 0.110% 0.560% 0.000%RI 2 1 1 1.379% 0.735% 11.111% 51,350 600 50,750 5.619% 0.345% 6.858%SC 5 4 1 0.611% 0.528% 1.613% 14,916 4,566 10,350 0.444% 0.623% 0.394%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 5 2 3 1.425% 1.235% 1.587% 41,989 6,626 35,363 0.739% 0.453% 0.837%TX 31 20 11 0.626% 0.434% 3.216% 420,783 160,639 260,144 1.676% 1.728% 1.645%UT 1 1 0 0.200% 0.220% 0.000% 88,900 88,900 0 3.482% 5.233% 0.000%VA 2 2 0 0.125% 0.140% 0.000% 680 680 0 0.013% 0.108% 0.000%VT 5 4 1 0.829% 0.714% 2.326% 4,419 239 4,180 0.900% 0.105% 1.584%WI 5 5 0 0.280% 0.283% 0.000% 17,828 17,828 0 0.441% 0.759% 0.000%WV 4 2 2 0.993% 0.823% 1.250% 2,305 324 1,981 0.163% 0.136% 0.168%WY 2 2 0 0.658% 0.781% 0.000% 153 153 0 0.034% 0.118% 0.000%Total 261 179 82 0.517% 0.388% 1.927% 8,082,653 1,010,901 7,071,752 3.562% 1.170% 5.032%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A14f. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 3 2 1 0.484% 0.422% 0.685% 654 620 34 0.108% 0.267% 0.009%AL 7 5 2 2.662% 2.475% 3.279% 295,146 28,485 266,661 6.997% 2.536% 8.616%AR 34 26 8 7.489% 6.806% 11.111% 117,725 57,747 59,978 4.799% 6.344% 3.887%AZ 5 3 2 0.472% 0.297% 4.167% 188,790 7,465 181,325 3.061% 0.267% 5.380%CA 47 24 23 1.286% 0.765% 4.449% 6,223,723 625,811 5,597,912 17.371% 4.630% 25.089%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 3 2 1 0.249% 0.171% 2.564% 38,567 2,834 35,733 1.416% 0.728% 1.531%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 10 10 0 0.661% 0.672% 0.000% 23,869 23,869 0 0.136% 0.157% 0.000%GA 7 3 4 0.384% 0.176% 3.448% 64,136 7,284 56,852 0.857% 0.457% 0.965%HI 4 2 2 3.774% 2.128% 16.667% 34,202 22,946 11,256 2.644% 1.852% 20.605%IA 6 4 2 0.568% 0.391% 6.061% 78,140 28,956 49,184 3.073% 2.019% 4.436%ID 3 2 1 0.321% 0.228% 1.754% 193,700 7,700 186,000 17.711% 0.919% 72.639%IL 23 19 4 1.608% 1.433% 3.846% 225,363 76,262 149,101 2.445% 2.527% 2.405%IN 4 3 1 0.271% 0.210% 2.273% 2,259 2,162 97 0.046% 0.084% 0.004%KY 18 1 17 7.469% 1.087% 11.409% 1,360,553 42 1,360,511 29.562% 0.011% 32.186%MA 5 3 2 0.696% 0.500% 1.695% 153,562 44,374 109,188 1.795% 2.536% 1.604%MD 11 8 3 1.044% 0.811% 4.412% 144,539 20,216 124,323 2.877% 1.972% 3.110%ME 5 5 0 0.617% 0.661% 0.000% 1,411 1,411 0 0.194% 0.482% 0.000%MI 8 3 5 0.269% 0.103% 8.197% 74,534 11,983 62,551 1.041% 0.606% 1.208%MN 13 11 2 0.822% 0.709% 6.667% 494,839 28,247 466,592 11.615% 0.938% 37.337%MO 9 5 4 0.635% 0.373% 5.195% 143,703 93,924 49,779 4.784% 5.559% 3.787%MT 4 3 1 0.472% 0.381% 1.667% 39,118 641 38,477 5.161% 0.175% 9.799%NC 31 22 9 1.310% 0.987% 6.475% 275,701 80,684 195,017 3.940% 4.656% 3.704%ND 1 0 1 0.481% 0.000% 3.704% 166 0 166 0.030% 0.000% 0.054%NE 20 19 1 2.594% 2.500% 9.091% 546,155 33,991 512,164 37.352% 4.957% 65.960%NH 2 1 1 0.159% 0.082% 2.439% 12,123 123 12,000 1.278% 0.031% 2.183%NJ 19 16 3 1.359% 1.176% 8.108% 1,088,924 110,182 978,742 14.053% 4.062% 19.435%NM 11 10 1 1.515% 1.456% 2.564% 87,943 86,683 1,260 5.177% 6.052% 0.473%NV 7 6 1 2.071% 1.893% 4.762% 18,306 10,006 8,300 1.880% 3.527% 1.203%NY 4 4 0 0.263% 0.311% 0.000% 19,060 19,060 0 0.390% 1.828% 0.000%OH 16 10 6 0.823% 0.550% 4.800% 244,937 32,451 212,486 2.395% 1.036% 2.995%OK 12 9 3 1.644% 1.737% 1.415% 26,926 10,169 16,757 0.862% 1.530% 0.681%OR 1 1 0 0.091% 0.106% 0.000% 3,220 3,220 0 0.110% 0.560% 0.000%RI 3 1 2 2.069% 0.735% 22.222% 119,613 600 119,013 13.088% 0.345% 16.083%SC 9 7 2 1.099% 0.925% 3.226% 36,110 16,029 20,081 1.076% 2.187% 0.765%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 8 2 6 2.279% 1.235% 3.175% 110,433 6,626 103,807 1.942% 0.453% 2.458%TX 60 40 20 1.212% 0.868% 5.848% 1,805,395 201,982 1,603,413 7.189% 2.173% 10.139%UT 1 1 0 0.200% 0.220% 0.000% 88,900 88,900 0 3.482% 5.233% 0.000%VA 4 3 1 0.250% 0.210% 0.585% 4,902 950 3,952 0.093% 0.151% 0.085%VT 7 6 1 1.161% 1.071% 2.326% 4,537 357 4,180 0.924% 0.157% 1.584%WI 5 5 0 0.280% 0.283% 0.000% 17,828 17,828 0 0.441% 0.759% 0.000%WV 5 2 3 1.241% 0.823% 1.875% 12,670 324 12,346 0.895% 0.136% 1.048%WY 4 3 1 1.316% 1.172% 2.083% 1,023 533 490 0.229% 0.412% 0.155%Total 459 312 147 0.910% 0.675% 3.454% 14,423,405 1,813,677 12,609,728 6.356% 2.099% 8.973%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A15. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 2 μg/L 28,808 4 0.014% 66,936,780 625 0.001%

	
 28,808 12 0.042% 66,936,780 1,645 0.002%> 2 μg/L 3,033 0 0.000% 115,100,195 0 0.000%

	
 3,033 0 0.000% 115,100,195 0 0.000%

> 2 μg/L 31,841 4 0.013% 182,036,975 625 0.000%

	
 31,841 12 0.038% 182,036,975 1,645 0.001%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A15a. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 103 52 51 0.000% 0.000% 0.000%AL 499 370 129 0.802% 0.000% 3.101% 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2AR 1,663 1,422 241 0.000% 0.000% 0.000%AZ 6,816 5,381 1,435 0.015% 0.019% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1CA 12,986 7,473 5,513 0.000% 0.000% 0.000%CO 2,556 1,854 702 0.000% 0.000% 0.000%CT 1,506 1,185 321 0.133% 0.169% 0.000% 2.2 2.2 2.2 2.2 2.2 2.2 2.2 2.2DE 272 254 18 0.000% 0.000% 0.000%FL 2,375 2,310 65 0.589% 0.606% 0.000% 0.008 0.008 0.1 0.1 0.22 0.22 0.71 0.71GA 1,491 1,410 81 0.000% 0.000% 0.000%HI 2,101 2,004 97 0.048% 0.050% 0.000% 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3IA 45 29 16 0.000% 0.000% 0.000%ID 1,806 1,548 258 0.000% 0.000% 0.000%IL 4,685 3,945 740 0.000% 0.000% 0.000%IN 2,234 2,070 164 0.000% 0.000% 0.000%KY 1,717 437 1,280 0.291% 0.000% 0.391% 0.06 0.06 0.25 0.25 0.3 0.3 0.3 0.3MA 2,964 2,184 780 0.135% 0.092% 0.256% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1MD 2,712 1,724 988 0.037% 0.058% 0.000% 1 1 1 1 1 1 1 1ME 387 339 48 0.000% 0.000% 0.000%MI 3,613 3,399 214 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 5,237 4,499 738 0.000% 0.000% 0.000%MT 2,994 2,693 301 0.000% 0.000% 0.000%NC 13,580 12,449 1,131 0.810% 0.884% 0.000% 0.04 0.04 0.565 0.565 1.85 1.85 5.4 5.4ND 409 343 66 0.000% 0.000% 0.000%NE 4,061 3,748 313 0.049% 0.053% 0.000% 0.3 0.3 0.305 0.305 0.31 0.31 0.31 0.31NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 5 5 0 0.000% 0.000% 0.000%NM 4,281 4,033 248 0.023% 0.025% 0.000% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02NV 1,620 1,198 422 0.000% 0.000% 0.000%NY 2,884 2,173 711 0.035% 0.046% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1OH 238 105 133 0.000% 0.000% 0.000%OKOR 2,050 1,567 483 0.000% 0.000% 0.000%RI 601 414 187 0.166% 0.242% 0.000% 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53SC 2,964 2,569 395 0.202% 0.195% 0.253% 0.4 0.4 0.9 1.075 1.13 0.9 1.7 1.7 0.9 1.7 1.7 0.9SD 953 844 109 0.000% 0.000% 0.000%TN 62 12 50 0.000% 0.000% 0.000%TX 11,042 5,282 5,760 0.036% 0.057% 0.017% 0.1 0.1 0.13 0.115 0.1 0.13 0.22 0.22 0.13 0.22 0.22 0.13UT 7,103 5,922 1,181 0.000% 0.000% 0.000%VA 501 178 323 0.000% 0.000% 0.000%VT 1,279 1,089 190 0.078% 0.092% 0.000% 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05WI 3,178 3,083 95 0.000% 0.000% 0.000%WV 643 336 307 1.711% 2.381% 0.977% 0.005 0.005 0.02 0.02 0.0137 0.02 0.02 0.02 0.5 0.5 0.02 0.5WY 1,283 963 320 0.078% 0.104% 0.000% 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4Total 128,453 101,389 27,064 0.132% 0.152% 0.059% 0.005 0.005 0.02 0.38 0.4 0.1 1.59 1.6 0.5 5.4 5.4 0.9

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A15b. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 15 9 6 246,299 14,189 232,110 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 171 126 45 2,702,037 589,449 2,112,588 0.585% 0.000% 2.222% 1.445% 0.000% 1.848%AR 450 379 71 2,447,627 905,863 1,541,764 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 946 898 48 6,079,868 2,709,277 3,370,591 0.106% 0.111% 0.000% 0.016% 0.037% 0.000%CA 1,602 1,315 287 33,465,085 11,798,465 21,666,620 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CO 814 595 219 4,993,005 526,096 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 662 624 38 2,596,395 262,508 2,333,887 0.151% 0.160% 0.000% 0.003% 0.030% 0.000%DE 115 112 3 480,758 199,358 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,308 1,287 21 16,785,207 14,546,031 2,239,176 0.612% 0.622% 0.000% 15.623% 18.027% 0.000%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 112 100 12 1,305,882 1,251,254 54,628 0.893% 1.000% 0.000% 4.860% 5.072% 0.000%IA 4 3 1 162,217 27,600 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 721 674 47 978,754 742,078 236,676 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,371 1,267 104 9,186,700 2,986,303 6,200,397 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,402 1,358 44 4,866,720 2,546,984 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 242 93 149 4,602,489 375,460 4,227,029 1.240% 0.000% 2.013% 6.983% 0.000% 7.603%MA 644 527 117 8,485,233 1,682,851 6,802,382 0.466% 0.380% 0.855% 0.905% 1.961% 0.643%MD 860 792 68 4,905,976 907,869 3,998,107 0.116% 0.126% 0.000% 0.006% 0.030% 0.000%ME 228 204 24 473,968 103,532 370,436 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,147 2,088 59 6,913,331 1,752,006 5,161,325 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,384 1,308 76 2,624,615 1,680,154 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 1.015% 1.077% 0.000% 0.064% 0.256% 0.000%ND 209 182 27 559,198 253,973 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 737 726 11 1,453,762 677,282 776,480 0.271% 0.275% 0.000% 0.153% 0.328% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 2 2 0 6,121 6,121 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 693 657 36 1,662,757 1,399,859 262,898 0.144% 0.152% 0.000% 1.416% 1.682% 0.000%NV 290 269 21 960,897 271,006 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,347 1,117 230 4,923,256 981,566 3,941,690 0.074% 0.090% 0.000% 0.001% 0.006% 0.000%OH 46 36 10 3,538,076 147,544 3,390,532 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,084 934 150 2,937,104 572,354 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 86 77 9 902,061 162,083 739,978 1.163% 1.299% 0.000% 0.007% 0.037% 0.000%SC 773 714 59 3,427,802 801,019 2,626,783 0.517% 0.420% 1.695% 1.190% 0.031% 1.544%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 13 6 7 675,214 145,112 530,102 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.200% 0.180% 0.297% 1.004% 0.137% 1.320%UT 426 390 36 2,500,736 1,667,550 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 437 404 33 436,586 185,422 251,164 0.229% 0.248% 0.000% 0.071% 0.166% 0.000%WI 1,409 1,389 20 3,883,768 2,192,024 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 343 196 147 1,368,815 204,156 1,164,659 2.624% 4.082% 0.680% 0.441% 0.812% 0.376%WY 304 256 48 446,177 129,229 316,948 0.329% 0.391% 0.000% 0.006% 0.021% 0.000%Total 31,841 28,808 3,033 182,036,975 66,936,780 115,100,195 0.210% 0.205% 0.264% 1.878% 4.124% 0.571%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A15c. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.151% 0.160% 0.000% 80 80 0 0.003% 0.030% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 3 0 0.127% 0.135% 0.000% 545 545 0 0.008% 0.031% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 4 4 0 0.013% 0.014% 0.000% 625 625 0 0.000% 0.001% 0.000%

Percent of Population Served 

with At Least One Detection 

> 2 μg/L

State

Number of Systems 

with At Least One Detection 

> 2 μg/L

Percent of Systems 

with At Least One Detection 

> 2 μg/L

Population Served by Systems 

with At Least One Detection 

> 2 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A15d. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.151% 0.160% 0.000% 80 80 0 0.003% 0.030% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 1 0 0.116% 0.126% 0.000% 276 276 0 0.006% 0.030% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 8 8 0 0.338% 0.359% 0.000% 1,139 1,139 0 0.017% 0.066% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 2 2 0 0.259% 0.280% 0.000% 150 150 0 0.004% 0.019% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 12 12 0 0.038% 0.042% 0.000% 1,645 1,645 0 0.001% 0.002% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A16. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.1 mg/L 44,905 37 0.082% 85,254,121 122,695 0.144%

	
 44,905 144 0.321% 85,254,121 1,064,526 1.249%

> 0.1 mg/L 4,003 6 0.150% 144,374,309 593,922 0.411%

	
 4,003 28 0.699% 144,374,309 8,424,108 5.835%

> 0.1 mg/L 48,908 43 0.088% 229,628,430 716,617 0.312%

	
 48,908 172 0.352% 229,628,430 9,488,634 4.132%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A16a. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 873 618 255 18.328% 21.036% 11.765% 0.00016 0.00054 0.00016 0.00308 0.00364 0.00078 0.00737 0.00763 0.00465 0.06 0.06 0.00511AL 2,684 1,821 863 3.949% 3.569% 4.751% 0.0008 0.001 0.0008 0.00163 0.002 0.0014 0.01 0.00937 0.01 0.06 0.02 0.06AR 2,163 1,507 656 5.317% 6.768% 1.982% 0.001 0.001 0.001 0.0014 0.0014 0.0012 0.0036 0.0036 0.0015 0.01 0.01 0.0019AZ 6,307 4,942 1,365 38.116% 34.480% 51.282% 0.0003 0.0003 0.00044 0.01 0.01 0.01 0.03 0.02 0.03 0.53 0.53 0.09CA 39,301 22,767 16,534 18.081% 19.375% 16.300% 9E-06 9E-06 9E-06 0.01 0.0092 0.01 0.02 0.02 0.02 0.64 0.64 0.12CO 4,381 2,326 2,055 20.155% 22.700% 17.275% 0.0001 0.0002 0.0001 0.0045 0.0067 0.0028 0.01 0.01 0.0091 0.12 0.06 0.12CT 2,588 1,865 723 5.216% 4.450% 7.192% 0.0001 0.0003 0.0001 0.002 0.006 0.001 0.05 0.06 0.003 0.15 0.15 0.006DE 686 638 48 63.557% 62.226% 81.250% 0.0001 0.0001 0.0001 0.0015 0.0014 0.002 0.0049 0.0053 0.0038 0.04 0.04 0.0063FL 2,146 2,077 69 29.031% 29.754% 7.246% 0.0002 0.0002 0.0014 0.0018 0.0018 0.003 0.01 0.01 0.008 0.12 0.12 0.008GA 2,884 2,490 394 0.069% 0.040% 0.254% 0.02 0.03 0.02 0.025 0.03 0.02 0.03 0.03 0.02 0.03 0.03 0.02HI 1,178 1,116 62 32.258% 34.050% 0.000% 0.002 0.002 0.003 0.003 0.008 0.008 0.01 0.01IA 1,492 1,231 261 1.743% 1.625% 2.299% 0.001 0.004 0.001 0.01 0.01 0.01 0.04 0.045 0.03 0.08 0.08 0.03ID 2,644 2,374 270 15.091% 16.217% 5.185% 0.00045 0.00045 0.002 0.005 0.005 0.0045 0.01 0.01 0.01 0.06 0.06 0.01IL 3,406 3,004 402 6.078% 5.959% 6.965% 0.0004 0.0004 0.004 0.006 0.006 0.0062 0.01 0.01 0.01 0.11 0.11 0.01IN 4,699 4,218 481 25.474% 26.505% 16.424% 0.0002 0.0002 0.0007 0.0069 0.0069 0.0068 0.02 0.02 0.02 0.1 0.1 0.03KY 1,777 544 1,233 10.129% 7.904% 11.111% 0.0001 0.0001 0.0001 0.002 0.0035 0.002 0.01 0.02 0.0083 0.03 0.03 0.03MA 2,934 1,972 962 3.885% 3.803% 4.054% 0.0003 0.0008 0.0003 0.0036 0.004 0.0034 0.01 0.01 0.01 0.06 0.04 0.06MD 5,107 3,983 1,124 8.028% 3.917% 22.598% 0.0002 0.0002 0.0002 0.003 0.00475 0.002 0.01 0.02 0.01 0.1 0.1 0.02ME 2,710 2,311 399 37.749% 41.281% 17.293% 0.0005 0.0005 0.0005 0.0012 0.0012 0.0008 0.0037 0.0039 0.0026 0.08 0.08 0.0054MI 6,138 5,964 174 28.315% 28.672% 16.092% 0.0006 0.0006 0.001 0.002 0.002 0.001 0.01 0.01 0.002 0.05 0.05 0.01MN 3,338 3,280 58 0.090% 0.091% 0.000% 0.01 0.01 0.02 0.02 0.05 0.05 0.05 0.05MO 5,687 4,909 778 6.260% 5.765% 9.383% 0.00101 0.00101 0.00102 0.0022 0.00224 0.00208 0.00355 0.00355 0.0031 0.01 0.01 0.00595MT 2,757 2,469 288 1.596% 1.499% 2.431% 0.001 0.001 0.001 0.003 0.003 0.002 0.02 0.01 0.03 0.06 0.06 0.03NC 9,230 7,792 1,438 2.546% 2.490% 2.851% 0.0001 0.0001 0.0002 0.005 0.006 0.0025 0.02 0.02 0.008 5.2 5.2 0.1ND 347 303 44 60.231% 64.356% 31.818% 0.00101 0.00101 0.00114 0.0034 0.00355 0.00173 0.01 0.01 0.00528 0.05 0.05 0.01NE 1,883 1,797 86 59.214% 59.265% 58.140% 0.001 0.001 0.00105 0.00299 0.003 0.00213 0.00859 0.00834 0.01 0.02 0.02 0.01NH 2,941 2,777 164 1.394% 1.476% 0.000% 0.001 0.001 0.0055 0.0055 0.02 0.02 0.08 0.08NJ 6,569 5,851 718 4.567% 4.085% 8.496% 0.00008 0.0005 0.00008 0.003 0.003 0.002 0.01 0.01 0.01 0.25 0.25 0.06NM 3,513 3,187 326 60.689% 62.096% 46.933% 1.3E-05 1.3E-05 0.0001 0.003 0.003 0.003 0.0094 0.0095 0.008 0.08 0.08 0.02NV 1,877 1,301 576 45.551% 50.423% 34.549% 0.0009 0.0009 0.001 0.004 0.005 0.004 0.01 0.01 0.01 0.14 0.14 0.02NY 3,498 2,559 939 8.548% 7.776% 10.650% 0.0004 0.00044 0.0004 0.00319 0.0036 0.0021 0.0084 0.0089 0.00625 0.54 0.54 0.02OH 4,074 3,428 646 5.400% 6.068% 1.858% 0.00011 0.001 0.00011 0.01 0.01 0.0028 0.02 0.02 0.02 0.04 0.04 0.03OK 420 346 74 24.048% 16.763% 58.108% 0.001 0.001 0.01 0.03 0.03 0.05 0.06 0.06 0.07 0.16 0.16 0.08OR 1,323 960 363 9.221% 10.729% 5.234% 0.00011 0.0005 0.00011 0.00166 0.0015 0.00185 0.00441 0.00441 0.02 0.02 0.01 0.02RI 892 661 231 6.839% 6.505% 7.792% 0.005 0.005 0.005 0.007 0.007 0.007 0.01 0.01 0.01 0.03 0.01 0.03SC 3,448 2,984 464 1.160% 1.340% 0.000% 0.01 0.01 0.02 0.02 0.085 0.085 0.2 0.2SD 388 359 29 37.629% 37.326% 41.379% 0.0006 0.0006 0.0008 0.0036 0.00365 0.0032 0.01 0.01 0.0066 0.03 0.03 0.01TN 1,658 485 1,173 3.317% 3.918% 3.069% 0.001 0.0014 0.001 0.0026 0.0026 0.0026 0.02 0.02 0.01 0.05 0.04 0.05TX 14,914 12,332 2,582 12.854% 13.055% 11.890% 0.001 0.001 0.001 0.00369 0.00411 0.00236 0.01 0.01 0.00568 0.14 0.14 0.04UT 6,945 5,447 1,498 9.258% 8.372% 12.483% 0.0001 0.001 0.0001 0.006 0.00695 0.0049 0.02 0.02 0.02 0.14 0.14 0.14VA 2,807 2,197 610 1.710% 1.866% 1.148% 0.001 0.001 0.003 0.01 0.01 0.01 0.01 0.01 0.01 0.61 0.61 0.01VT 2,083 1,755 328 3.313% 3.590% 1.829% 0.00027 0.00027 0.001 0.003 0.003 0.017 0.03 0.01 0.32 0.32 0.08 0.32WI 7,017 6,847 170 25.281% 24.726% 47.647% 0.00005 0.00005 0.00047 0.0017 0.0017 0.0026 0.01 0.01 0.01 0.42 0.42 0.01WV 1,115 425 690 4.126% 5.882% 3.043% 0.00028 0.001 0.00028 0.00249 0.002 0.00297 0.01 0.0094 0.01 0.02 0.02 0.02WY 1,130 875 255 2.389% 1.943% 3.922% 0.0007 0.001 0.0007 0.0037 0.0038 0.00285 0.02 0.02 0.0137 0.08 0.08 0.02Total 185,952 143,094 42,858 15.328% 15.696% 14.098% 9E-06 9E-06 9E-06 0.00415 0.004 0.006 0.01 0.01 0.02 5.2 5.2 0.32

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A16b. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 494 392 102 550,696 210,676 340,020 28.340% 30.612% 19.608% 58.648% 44.688% 67.298%AL 352 279 73 4,701,100 1,463,066 3,238,034 17.614% 13.620% 32.877% 21.547% 10.711% 26.443%AR 453 381 72 2,452,800 909,774 1,543,026 16.336% 16.535% 15.278% 16.180% 30.775% 7.575%AZ 1,049 1,001 48 6,161,306 2,790,715 3,370,591 65.586% 64.935% 79.167% 90.247% 80.259% 98.517%CA 3,726 3,206 520 36,184,328 13,391,438 22,792,890 33.682% 33.250% 36.346% 61.672% 55.862% 65.086%CO 838 617 221 4,998,506 533,275 4,465,231 45.346% 41.005% 57.466% 71.311% 53.259% 73.467%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 7.692% 6.631% 38.462% 51.679% 10.602% 58.407%DE 280 277 3 679,723 398,323 281,400 78.214% 77.978% 100.000% 95.635% 92.551% 100.000%FL 1,331 1,305 26 17,170,469 14,924,427 2,246,042 36.063% 36.398% 19.231% 41.965% 45.397% 19.159%GA 1,600 1,485 115 7,244,380 1,352,049 5,892,331 0.125% 0.067% 0.870% 0.241% 0.005% 0.295%HI 107 95 12 1,303,767 1,249,139 54,628 42.056% 47.368% 0.000% 83.732% 87.394% 0.000%IA 966 933 33 2,500,343 1,391,717 1,108,626 1.760% 1.501% 9.091% 11.875% 5.261% 20.178%ID 893 847 46 1,047,634 805,559 242,075 25.644% 26.328% 13.043% 59.193% 50.401% 88.454%IL 1,490 1,387 103 9,168,134 2,968,062 6,200,072 11.208% 10.671% 18.447% 52.122% 20.600% 67.212%IN 1,622 1,573 49 4,979,847 2,619,392 2,360,455 38.779% 38.334% 53.061% 56.974% 56.626% 57.361%KY 242 93 149 4,602,489 375,460 4,227,029 33.884% 27.957% 37.584% 46.067% 47.799% 45.913%MA 676 558 118 8,525,575 1,718,151 6,807,424 11.538% 10.394% 16.949% 48.915% 10.397% 58.636%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 12.139% 11.443% 22.059% 40.340% 12.564% 47.457%ME 807 753 54 727,775 292,171 435,604 73.110% 74.635% 51.852% 44.445% 81.021% 19.912%MI 2,994 2,942 52 6,682,527 1,890,196 4,792,331 46.961% 47.417% 21.154% 22.623% 47.023% 13.000%MN 1,459 1,432 27 3,959,159 2,725,622 1,233,537 0.206% 0.209% 0.000% 0.541% 0.786% 0.000%MO 1,421 1,344 77 3,006,743 1,692,282 1,314,461 15.201% 13.616% 42.857% 26.766% 31.685% 20.433%MT 846 787 59 757,540 365,141 392,399 3.901% 3.685% 6.780% 11.199% 22.024% 1.126%NC 2,285 2,146 139 6,973,879 1,708,713 5,265,166 8.140% 7.735% 14.388% 27.250% 17.762% 30.329%ND 217 190 27 563,069 257,844 305,225 66.359% 70.000% 40.741% 38.932% 58.255% 22.609%NE 731 720 11 1,449,290 672,810 776,480 70.725% 70.556% 81.818% 86.523% 72.096% 99.024%NH 1,216 1,175 41 942,517 392,718 549,799 2.796% 2.894% 0.000% 2.678% 6.427% 0.000%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 11.063% 10.396% 35.135% 39.061% 19.241% 49.791%NM 724 685 39 1,667,433 1,400,885 266,548 81.768% 81.752% 82.051% 94.160% 97.592% 76.121%NV 325 305 20 970,653 280,854 689,799 66.769% 65.574% 85.000% 93.740% 79.607% 99.494%NY 1,580 1,339 241 11,202,468 1,223,020 9,979,448 13.481% 11.128% 26.556% 17.482% 11.833% 18.174%OH 1,916 1,791 125 10,217,699 3,122,762 7,094,937 9.603% 9.883% 5.600% 20.211% 10.483% 24.493%OK 202 175 27 749,266 276,712 472,554 11.881% 12.000% 11.111% 41.134% 31.099% 47.011%OR 735 613 122 2,777,179 487,433 2,289,746 13.061% 13.866% 9.016% 43.130% 13.349% 49.470%RI 143 134 9 913,584 173,606 739,978 26.573% 24.627% 55.556% 31.470% 30.552% 31.686%SC 823 758 65 3,468,333 809,806 2,658,527 3.524% 3.826% 0.000% 1.093% 4.679% 0.000%SD 235 224 11 328,972 237,011 91,961 50.638% 50.446% 54.545% 49.957% 61.523% 20.149%TN 350 161 189 5,683,572 1,460,816 4,222,756 12.857% 9.317% 15.873% 23.007% 5.355% 29.113%TX 4,930 4,587 343 25,070,435 9,285,450 15,784,985 23.103% 22.695% 28.571% 39.452% 43.354% 37.157%UT 507 457 50 2,543,652 1,686,017 857,635 26.036% 24.945% 36.000% 66.160% 59.681% 78.898%VA 1,582 1,414 168 4,803,450 634,384 4,169,066 2.402% 2.405% 2.381% 2.487% 1.979% 2.564%VT 600 557 43 490,839 226,871 263,968 10.833% 10.772% 11.628% 3.851% 5.310% 2.597%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 44.542% 44.038% 90.000% 78.049% 64.299% 97.171%WV 452 291 161 1,415,612 234,822 1,180,790 7.522% 7.216% 8.075% 17.920% 9.340% 19.626%WY 304 255 49 446,184 129,168 317,016 6.250% 5.490% 10.204% 37.751% 24.235% 43.258%Total 48,908 44,905 4,003 229,628,430 85,254,121 144,374,309 24.209% 24.044% 26.055% 41.226% 40.204% 41.829%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A16c. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 4 4 0 0.381% 0.400% 0.000% 26,656 26,656 0 0.433% 0.955% 0.000%CA 10 8 2 0.268% 0.250% 0.385% 334,074 66,156 267,918 0.923% 0.494% 1.175%CO 1 0 1 0.119% 0.000% 0.452% 7,124 0 7,124 0.143% 0.000% 0.160%CT 2 2 0 0.171% 0.177% 0.000% 505 505 0 0.019% 0.132% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.075% 0.077% 0.000% 65 65 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.067% 0.072% 0.000% 60 60 0 0.001% 0.002% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 3 0 0.131% 0.140% 0.000% 1,170 1,170 0 0.017% 0.068% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 6 6 0 0.437% 0.449% 0.000% 1,355 1,355 0 0.017% 0.050% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 1 0 0.308% 0.328% 0.000% 200 200 0 0.021% 0.071% 0.000%NY 1 1 0 0.063% 0.075% 0.000% 100 100 0 0.001% 0.008% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 1 1 0 0.495% 0.571% 0.000% 4,056 4,056 0 0.541% 1.466% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 1 0 0.122% 0.132% 0.000% 16,197 16,197 0 0.467% 2.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 758 758 0 0.003% 0.008% 0.000%UT 5 3 2 0.986% 0.656% 4.000% 319,950 1,550 318,400 12.578% 0.092% 37.125%VA 1 1 0 0.063% 0.071% 0.000% 34 34 0 0.001% 0.005% 0.000%VT 1 0 1 0.167% 0.000% 2.326% 480 0 480 0.098% 0.000% 0.182%WI 3 3 0 0.165% 0.166% 0.000% 3,833 3,833 0 0.095% 0.163% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 43 37 6 0.088% 0.082% 0.150% 716,617 122,695 593,922 0.312% 0.144% 0.411%

Percent of Population Served 

with At Least One Detection 

> 0.1 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.1 mg/L

Percent of Systems 

with At Least One Detection 

> 0.1 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.1 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A16d. Chromium (total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.202% 0.255% 0.000% 96 96 0 0.017% 0.046% 0.000%AL 1 0 1 0.284% 0.000% 1.370% 2,400 0 2,400 0.051% 0.000% 0.074%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 28 22 6 2.669% 2.198% 12.500% 2,496,990 211,683 2,285,307 40.527% 7.585% 67.801%CA 30 23 7 0.805% 0.717% 1.346% 5,198,940 365,698 4,833,242 14.368% 2.731% 21.205%CO 4 2 2 0.477% 0.324% 0.905% 53,002 190 52,812 1.060% 0.036% 1.183%CT 16 16 0 1.368% 1.415% 0.000% 13,371 13,371 0 0.492% 3.498% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 3 3 0 0.225% 0.230% 0.000% 41,226 41,226 0 0.240% 0.276% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.207% 0.214% 0.000% 761 761 0 0.030% 0.055% 0.000%ID 1 1 0 0.112% 0.118% 0.000% 116 116 0 0.011% 0.014% 0.000%IL 3 3 0 0.201% 0.216% 0.000% 844 844 0 0.009% 0.028% 0.000%IN 5 5 0 0.308% 0.318% 0.000% 79,139 79,139 0 1.589% 3.021% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 1 0 1 0.148% 0.000% 0.847% 37,615 0 37,615 0.441% 0.000% 0.553%MD 5 5 0 0.482% 0.515% 0.000% 18,754 18,754 0 0.373% 1.831% 0.000%ME 1 1 0 0.124% 0.133% 0.000% 15,000 15,000 0 2.061% 5.134% 0.000%MI 4 4 0 0.134% 0.136% 0.000% 535 535 0 0.008% 0.028% 0.000%MN 1 1 0 0.069% 0.070% 0.000% 233 233 0 0.006% 0.009% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 80 80 0 0.011% 0.022% 0.000%NC 8 7 1 0.350% 0.326% 0.719% 10,121 4,466 5,655 0.145% 0.261% 0.107%ND 1 1 0 0.461% 0.526% 0.000% 466 466 0 0.083% 0.181% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 1 1 0 0.082% 0.085% 0.000% 145 145 0 0.015% 0.037% 0.000%NJ 9 8 1 0.655% 0.598% 2.703% 739,714 63,460 676,254 9.529% 2.328% 13.429%NM 2 2 0 0.276% 0.292% 0.000% 5,118 5,118 0 0.307% 0.365% 0.000%NV 2 2 0 0.615% 0.656% 0.000% 960 960 0 0.099% 0.342% 0.000%NY 1 1 0 0.063% 0.075% 0.000% 100 100 0 0.001% 0.008% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 9 7 2 4.455% 4.000% 7.407% 257,518 57,519 199,999 34.369% 20.787% 42.323%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 7 7 0 0.851% 0.923% 0.000% 19,187 19,187 0 0.553% 2.369% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 0 1 0.286% 0.000% 0.529% 4,694 0 4,694 0.083% 0.000% 0.111%TX 4 4 0 0.081% 0.087% 0.000% 157,394 157,394 0 0.628% 1.695% 0.000%UT 9 5 4 1.775% 1.094% 8.000% 326,080 1,830 324,250 12.819% 0.109% 37.807%VA 1 1 0 0.063% 0.071% 0.000% 34 34 0 0.001% 0.005% 0.000%VT 4 2 2 0.667% 0.359% 4.651% 2,215 335 1,880 0.451% 0.148% 0.712%WI 5 5 0 0.274% 0.277% 0.000% 5,586 5,586 0 0.138% 0.237% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 1 1 0 0.329% 0.392% 0.000% 200 200 0 0.045% 0.155% 0.000%Total 172 144 28 0.352% 0.321% 0.699% 9,488,634 1,064,526 8,424,108 4.132% 1.249% 5.835%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A17. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.2 mg/L 29,277 39 0.133% 66,122,477 222,909 0.337%

	
 29,277 91 0.311% 66,122,477 546,722 0.827%

> 0.2 mg/L 2,790 5 0.179% 96,336,123 33,999 0.035%	
 2,790 26 0.932% 96,336,123 1,304,404 1.354%

> 0.2 mg/L 32,067 44 0.137% 162,458,600 256,908 0.158%

	
 32,067 117 0.365% 162,458,600 1,851,126 1.139%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A17a. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 1,491 1,063 428 1.006% 1.223% 0.467% 0.0058 0.0058 0.006 0.0078 0.0078 0.103 0.1 0.02 0.2 0.2 0.1 0.2AL 2,652 1,833 819 1.697% 1.146% 2.930% 0.001 0.003 0.001 0.02 0.02 0.02 0.09 0.06 0.2 0.33 0.33 0.3AR 2,234 1,576 658 2.238% 3.109% 0.152% 0.05 0.05 0.2 0.18 0.18 0.2 0.58 0.58 0.2 0.96 0.96 0.2AZ 5,817 4,579 1,238 1.014% 1.157% 0.485% 0.005 0.005 0.008 0.01 0.01 0.045 0.08 0.05 0.1 0.24 0.24 0.1CA 21,206 11,890 9,316 0.307% 0.378% 0.215% 0.0011 0.0011 0.002 0.04 0.09 0.02 0.1 0.1 0.105 0.22 0.22 0.17CO 737 391 346 4.613% 5.115% 4.046% 0.0061 0.007 0.0061 0.01 0.01 0.015 0.04 0.02 0.15 0.2 0.04 0.2CT 2,595 1,868 727 1.426% 1.338% 1.651% 0.01 0.01 0.01 0.01 0.01 0.065 0.15 0.15 0.1 0.26 0.26 0.17DE 204 201 3 0.490% 0.498% 0.000% 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008FL 2,151 2,082 69 6.927% 6.868% 8.696% 0.001 0.001 0.003 0.005 0.005 0.0055 0.01 0.01 0.01 0.2 0.2 0.01GA 7 6 1 0.000% 0.000% 0.000%HI 3,166 3,075 91 0.000% 0.000% 0.000%IA 32 23 9 9.375% 0.000% 33.333% 0.01 0.01 0.01 0.01 0.03 0.03 0.03 0.03ID 475 443 32 1.263% 1.129% 3.125% 0.006 0.006 0.007 0.01 0.01 0.007 0.03 0.03 0.007 0.03 0.03 0.007IL 2,800 2,386 414 1.464% 1.509% 1.208% 0.005 0.005 0.01 0.01 0.01 0.01 0.07 0.07 0.03 0.2 0.2 0.03IN 3,800 3,568 232 2.263% 2.214% 3.017% 0.0009 0.0009 0.009 0.01 0.01 0.05 0.05 0.03 0.09 0.11 0.11 0.09KY 1,754 529 1,225 4.333% 2.457% 5.143% 0.001 0.001 0.002 0.01 0.02 0.01 0.03 0.03 0.03 0.57 0.06 0.57MA 2,956 1,996 960 1.996% 1.954% 2.083% 0.004 0.01 0.004 0.02 0.02 0.01 0.05 0.05 0.02 0.07 0.07 0.02MD 81 53 28 25.926% 37.736% 3.571% 0.001 0.001 0.04 0.01 0.01 0.04 0.01 0.01 0.04 0.04 0.01 0.04ME 2,046 1,706 340 1.515% 1.524% 1.471% 0.005 0.005 0.005 0.006 0.0075 0.005 0.01 0.02 0.01 0.02 0.02 0.01MI 6,016 6,011 5 0.050% 0.050% 0.000% 0.005 0.005 0.005 0.005 0.15 0.15 0.15 0.15MN 4,456 4,368 88 0.314% 0.321% 0.000% 0.1 0.1 0.16 0.16 0.4 0.4 1.59 1.59MO 2,748 2,726 22 0.073% 0.073% 0.000% 0.16 0.16 0.185 0.185 0.21 0.21 0.21 0.21MT 39 28 11 2.564% 0.000% 9.091% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01NC 9,239 7,796 1,443 2.316% 1.911% 4.505% 0.002 0.002 0.002 0.005 0.005 0.004 0.03 0.03 0.04 0.18 0.18 0.18ND 45 26 19 11.111% 19.231% 0.000% 0.005 0.005 0.005 0.005 0.01 0.01 0.01 0.01NE 3,133 3,021 112 0.255% 0.265% 0.000% 0.08 0.08 0.16 0.16 0.34 0.34 0.34 0.34NH 2,945 2,781 164 0.917% 0.971% 0.000% 0.00314 0.00314 0.01 0.01 0.23 0.23 1.6 1.6NJ 5,960 5,484 476 2.869% 2.936% 2.101% 0.001 0.001 0.002 0.004 0.004 0.0045 0.02 0.02 0.02 0.14 0.14 0.02NM 3,477 3,163 314 1.582% 1.518% 2.229% 0.0039 0.0039 0.006 0.17 0.165 0.19 0.79 0.79 1.88 1.88 1.88 1.88NV 1,976 1,492 484 0.709% 0.603% 1.033% 0.005 0.005 0.01 0.01 0.02 0.01 0.07 0.07 0.11 0.11 0.07 0.11NY 3,227 2,433 794 2.882% 3.206% 1.889% 0.0009 0.0009 0.002 0.003 0.002 0.01 0.03 0.03 0.1 0.3 0.3 0.14OH 3,287 2,698 589 0.913% 0.815% 1.358% 0.005 0.005 0.005 0.01 0.0095 0.015 0.02 0.02 0.04 0.04 0.03 0.04OK 16 12 4 0.000% 0.000% 0.000%OR 1,308 949 359 0.459% 0.527% 0.279% 0.0055 0.009 0.0055 0.02 0.02 0.0055 1.88 1.88 0.0055 1.88 1.88 0.0055RI 845 614 231 0.237% 0.326% 0.000% 0.01 0.01 0.015 0.015 0.02 0.02 0.02 0.02SCSD 98 91 7 1.020% 1.099% 0.000% 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005TN 1,796 635 1,161 4.287% 3.150% 4.910% 0.002 0.002 0.002 0.0053 0.00545 0.005 0.02 0.015 0.02 0.08 0.02 0.08TX 491 488 3 0.815% 0.820% 0.000% 0.01 0.01 0.01 0.01 0.02 0.02 0.02 0.02UT 6,923 5,441 1,482 4.622% 4.190% 6.208% 0.001 0.0012 0.001 0.003 0.004 0.002 0.01 0.02 0.01 0.28 0.08 0.28VA 1,155 961 194 1.039% 0.937% 1.546% 0.006 0.006 0.01 0.01 0.01 0.01 0.04 0.07 0.03 0.07 0.07 0.03VT 1,934 1,596 338 1.706% 1.754% 1.479% 0.003 0.003 0.01 0.01 0.01 0.01 0.02 0.05 0.02 0.2 0.2 0.02WI 602 532 70 2.159% 2.444% 0.000% 0.001 0.001 0.005 0.005 0.01 0.01 0.03 0.03WV 1,106 424 682 4.882% 8.255% 2.786% 0.002 0.002 0.002 0.007 0.007 0.007 0.04 0.04 0.04 0.1 0.07 0.1WY 1,342 893 449 0.373% 0.560% 0.000% 0.0026 0.0026 0.01 0.01 1.93 1.93 1.93 1.93Total 120,368 93,931 26,437 1.613% 1.559% 1.808% 0.0009 0.0009 0.001 0.0089 0.009 0.0085 0.08 0.1 0.05 1.93 1.93 1.88

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A17b. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 609 467 142 568,407 230,700 337,707 2.463% 2.784% 1.408% 2.871% 2.420% 3.180%AL 352 279 73 4,701,100 1,463,066 3,238,034 7.955% 5.376% 17.808% 31.047% 12.510% 39.423%AR 453 381 72 2,452,800 909,774 1,543,026 2.428% 2.625% 1.389% 0.676% 1.071% 0.443%AZ 1,047 999 48 6,145,727 2,775,136 3,370,591 4.680% 4.605% 6.250% 40.905% 30.273% 49.658%CA 1,801 1,479 322 34,623,489 12,638,467 21,985,022 2.277% 1.758% 4.658% 4.500% 4.833% 4.308%CO 318 198 120 3,180,552 240,188 2,940,364 8.491% 7.071% 10.833% 52.182% 16.776% 55.075%CT 1,169 1,130 39 2,716,062 382,140 2,333,922 2.652% 2.212% 15.385% 19.305% 1.258% 22.259%DE 112 111 1 229,152 89,152 140,000 0.893% 0.901% 0.000% 0.058% 0.148% 0.000%FL 1,336 1,310 26 17,258,004 15,011,962 2,246,042 6.961% 6.870% 11.538% 35.735% 38.535% 17.019%GA 6 5 1 46,526 43,855 2,671 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 112 100 12 1,305,882 1,251,254 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 15 14 1 176,854 42,237 134,617 6.667% 0.000% 100.000% 76.118% 0.000% 100.000%ID 273 261 12 776,003 556,213 219,790 2.198% 1.916% 8.333% 24.559% 0.823% 84.626%IL 1,231 1,130 101 9,073,158 2,873,930 6,199,228 3.168% 3.097% 3.960% 1.834% 4.601% 0.551%IN 1,543 1,500 43 4,582,001 2,258,101 2,323,900 5.250% 5.067% 11.628% 33.062% 15.284% 50.336%KY 242 93 149 4,602,489 375,460 4,227,029 23.967% 12.903% 30.872% 29.176% 5.821% 31.250%MA 676 558 118 8,521,949 1,714,525 6,807,424 5.917% 5.018% 10.169% 47.502% 7.885% 57.480%MD 47 37 10 345,679 150,329 195,350 38.298% 45.946% 10.000% 12.499% 7.481% 16.360%ME 789 735 54 726,469 290,865 435,604 3.929% 3.537% 9.259% 9.624% 8.736% 10.218%MI 2,739 2,735 4 967,203 907,315 59,888 0.110% 0.110% 0.000% 0.044% 0.047% 0.000%MN 1,593 1,564 29 4,265,262 3,015,621 1,249,641 0.753% 0.767% 0.000% 0.694% 0.981% 0.000%MO 989 979 10 994,458 920,265 74,193 0.202% 0.204% 0.000% 0.049% 0.052% 0.000%MT 29 24 5 87,746 12,156 75,590 3.448% 0.000% 20.000% 0.097% 0.000% 0.112%NC 2,284 2,145 139 6,973,608 1,708,442 5,265,166 6.611% 5.315% 26.619% 22.769% 7.665% 27.669%ND 26 20 6 63,288 56,259 7,029 19.231% 25.000% 0.000% 1.139% 1.282% 0.000%NE 745 734 11 1,450,799 674,319 776,480 0.537% 0.545% 0.000% 0.025% 0.053% 0.000%NH 1,218 1,177 41 942,646 392,847 549,799 2.053% 2.124% 0.000% 0.878% 2.107% 0.000%NJ 1,359 1,324 35 7,013,180 2,687,928 4,325,252 8.830% 8.535% 20.000% 13.490% 18.748% 10.222%NM 712 674 38 1,671,607 1,405,084 266,523 5.899% 5.638% 10.526% 12.351% 5.775% 47.024%NV 335 314 21 973,342 283,451 689,891 3.582% 2.548% 19.048% 38.089% 6.901% 50.902%NY 1,532 1,296 236 4,371,133 1,200,988 3,170,145 6.070% 6.019% 6.356% 6.991% 5.799% 7.443%OH 1,892 1,767 125 10,214,857 3,119,920 7,094,937 1.533% 1.188% 6.400% 4.037% 2.527% 4.701%OK 11 7 4 77,209 2,175 75,034 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OR 727 606 121 2,769,817 486,571 2,283,246 0.825% 0.825% 0.826% 1.143% 3.240% 0.696%RI 141 132 9 913,234 173,256 739,978 1.418% 1.515% 0.000% 0.514% 2.710% 0.000%SCSD 29 26 3 31,974 26,332 5,642 3.448% 3.846% 0.000% 6.474% 7.861% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 17.379% 10.494% 23.280% 25.967% 3.829% 33.635%TX 420 418 2 530,258 527,971 2,287 0.714% 0.718% 0.000% 0.634% 0.637% 0.000%UT 507 457 50 2,543,652 1,686,017 857,635 17.357% 15.755% 32.000% 42.914% 29.652% 68.986%VA 690 594 96 2,788,445 362,621 2,425,824 1.739% 1.515% 3.125% 10.851% 0.989% 12.326%VT 600 556 44 492,901 226,733 266,168 4.500% 4.137% 9.091% 3.362% 4.474% 2.414%WI 250 232 18 2,742,526 1,122,262 1,620,264 4.400% 4.741% 0.000% 1.886% 4.610% 0.000%WV 453 292 161 1,415,710 234,920 1,180,790 9.713% 10.959% 7.453% 2.563% 6.867% 1.707%WY 304 255 49 446,184 129,168 317,016 1.645% 1.961% 0.000% 0.354% 1.222% 0.000%Total 32,067 29,277 2,790 162,458,600 66,122,477 96,336,123 4.144% 3.559% 10.287% 17.428% 14.736% 19.276%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A17c. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 2 1 1 0.568% 0.358% 1.370% 105,803 93,078 12,725 2.251% 6.362% 0.393%AR 7 7 0 1.545% 1.837% 0.000% 3,906 3,906 0 0.159% 0.429% 0.000%AZ 2 2 0 0.191% 0.200% 0.000% 47,633 47,633 0 0.775% 1.716% 0.000%CA 1 1 0 0.056% 0.068% 0.000% 3,100 3,100 0 0.009% 0.025% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.086% 0.088% 0.000% 500 500 0 0.018% 0.131% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 7,716 0 7,716 0.168% 0.000% 0.183%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 2 2 0 0.126% 0.128% 0.000% 5,552 5,552 0 0.130% 0.184% 0.000%MO 1 1 0 0.101% 0.102% 0.000% 450 450 0 0.045% 0.049% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 1 1 0 0.134% 0.136% 0.000% 29 29 0 0.002% 0.004% 0.000%NH 3 3 0 0.246% 0.255% 0.000% 1,632 1,632 0 0.173% 0.415% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 18 16 2 2.528% 2.374% 5.263% 68,241 64,912 3,329 4.082% 4.620% 1.249%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 2 2 0 0.131% 0.154% 0.000% 1,867 1,867 0 0.043% 0.155% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 1 1 0 0.138% 0.165% 0.000% 70 70 0 0.003% 0.014% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SCSD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 1 0 1 0.197% 0.000% 2.000% 10,229 0 10,229 0.402% 0.000% 1.193%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 1 1 0 0.329% 0.392% 0.000% 180 180 0 0.040% 0.139% 0.000%Total 44 39 5 0.137% 0.133% 0.179% 256,908 222,909 33,999 0.158% 0.337% 0.035%

Percent of Population Served 

with At Least One Detection 

> 0.2 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.2 mg/L

Percent of Systems 

with At Least One Detection 

> 0.2 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.2 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A17d. Cyanide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 2 1 1 0.328% 0.214% 0.704% 10,194 47 10,147 1.793% 0.020% 3.005%AL 3 1 2 0.852% 0.358% 2.740% 328,201 93,078 235,123 6.981% 6.362% 7.261%AR 8 7 1 1.766% 1.837% 1.389% 10,734 3,906 6,828 0.438% 0.429% 0.443%AZ 5 4 1 0.478% 0.400% 2.083% 188,199 48,199 140,000 3.062% 1.737% 4.154%CA 12 8 4 0.666% 0.541% 1.242% 757,492 218,449 539,043 2.188% 1.728% 2.452%CO 2 0 2 0.629% 0.000% 1.667% 36,237 0 36,237 1.139% 0.000% 1.232%CT 5 3 2 0.428% 0.265% 5.128% 88,731 585 88,146 3.267% 0.153% 3.777%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 3 3 0 0.225% 0.229% 0.000% 53,652 53,652 0 0.311% 0.357% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 2 2 0 0.162% 0.177% 0.000% 1,160 1,160 0 0.013% 0.040% 0.000%IN 1 1 0 0.065% 0.067% 0.000% 70 70 0 0.002% 0.003% 0.000%KY 3 0 3 1.240% 0.000% 2.013% 98,525 0 98,525 2.141% 0.000% 2.331%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 1 1 0 0.037% 0.037% 0.000% 30 30 0 0.003% 0.003% 0.000%MN 12 12 0 0.753% 0.767% 0.000% 29,582 29,582 0 0.694% 0.981% 0.000%MO 2 2 0 0.202% 0.204% 0.000% 483 483 0 0.049% 0.052% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 4 2 2 0.175% 0.093% 1.439% 30,104 13,062 17,042 0.432% 0.765% 0.324%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 3 3 0 0.403% 0.409% 0.000% 162 162 0 0.011% 0.024% 0.000%NH 4 4 0 0.328% 0.340% 0.000% 1,795 1,795 0 0.190% 0.457% 0.000%NJ 2 2 0 0.147% 0.151% 0.000% 300 300 0 0.004% 0.011% 0.000%NM 30 27 3 4.213% 4.006% 7.895% 154,053 78,023 76,030 9.216% 5.553% 28.527%NV 1 0 1 0.299% 0.000% 4.762% 15,200 0 15,200 1.562% 0.000% 2.203%NY 5 3 2 0.326% 0.231% 0.847% 33,121 3,067 30,054 0.758% 0.255% 0.948%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 2 2 0 0.275% 0.330% 0.000% 492 492 0 0.018% 0.101% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SCSD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 1 0 1 0.197% 0.000% 2.000% 10,229 0 10,229 0.402% 0.000% 1.193%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 1 1 0 0.167% 0.180% 0.000% 200 200 0 0.041% 0.088% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 0 1 0.221% 0.000% 0.621% 1,800 0 1,800 0.127% 0.000% 0.152%WY 2 2 0 0.658% 0.784% 0.000% 380 380 0 0.085% 0.294% 0.000%Total 117 91 26 0.365% 0.311% 0.932% 1,851,126 546,722 1,304,404 1.139% 0.827% 1.354%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A18. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 200 μg/L 25,558 1 0.004% 64,625,469 20,114 0.031%	
 25,558 1 0.004% 64,625,469 20,114 0.031%> 200 μg/L 2,829 0 0.000% 113,560,642 0 0.000%

	
 2,829 0 0.000% 113,560,642 0 0.000%

> 200 μg/L 28,387 1 0.004% 178,186,111 20,114 0.011%	
 28,387 1 0.004% 178,186,111 20,114 0.011%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A18a. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 69 36 33 0.000% 0.000% 0.000%AL 617 408 209 0.648% 0.490% 0.957% 0.4 0.4 1.2 4.25 3.85 18.75 36.3 7.3 36.3 36.3 7.3 36.3AR 1,588 1,357 231 0.000% 0.000% 0.000%AZ 6,851 5,425 1,426 0.204% 0.111% 0.561% 0.3 0.3 1 1 1 1.2 1.6 1 1.7 1.7 1 1.7CA 13,777 8,242 5,535 0.051% 0.036% 0.072% 0.04 1 0.04 1.9 1 1.95 19 10 19 19 10 19CO 2,550 1,857 693 0.510% 0.323% 1.010% 1 1 1.7 2.7 2.8 2.6 8.1 8.1 46 46 8.1 46CT 1,317 1,002 315 0.304% 0.200% 0.635% 0.2 0.2 3.8 2.9 1.1 3.9 424424DE 826 788 38 0.000% 0.000% 0.000%FL 2,510 2,442 68 4.661% 4.750% 1.471% 0.01 0.01 0.33 1.8 1.85 0.33 5.4 5.4 0.33 33 33 0.33GA 1,433 1,355 78 0.000% 0.000% 0.000%HIIA 1,746 1,606 140 0.401% 0.062% 4.286% 0.33 0.33 0.35 0.68 0.33 0.94 1.7 0.33 1.7 1.7 0.33 1.7ID 2,036 1,767 269 0.098% 0.113% 0.000% 0.12 0.12 0.305 0.305 0.49 0.49 0.49 0.49IL 3,191 2,642 549 0.000% 0.000% 0.000%IN 2,324 2,154 170 0.430% 0.279% 2.353% 1 1 1 1.8 2.2 1.55 50.9 98 2.2 98 98 2.2KY 1,780 444 1,336 2.247% 0.000% 2.994% 0.04 0.04 1.3 1.3 6.8 6.8 10 10MA 2,989 2,186 803 0.234% 0.137% 0.498% 0.5 1 0.5 1 1 1 2.2 2.2 1.7 2.2 2.2 1.7MD 2,468 1,697 771 9.198% 4.302% 19.974% 0.01 0.01 0.05 0.56 0.3 0.68 1.89 1.34 2.29 5.24 2.43 5.24ME 378 317 61 0.265% 0.000% 1.639% 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1MI 3,939 1,404 2,535 0.609% 0.071% 0.907% 131232232333MN 4,586 4,452 134 0.981% 0.809% 6.716% 0.5 0.5 0.5 0.7 0.7 0.7 1.1 1.2 1 2 2 1MO 5,797 4,978 819 0.242% 0.281% 0.000% 1.03 1.03 2.965 2.965 29.5 29.5 1210 1210MT 3,187 2,905 282 0.157% 0.069% 1.064% 1.52 1.52 2.82 2.82 2.01 3.3 3.5 2.5 3.5 3.5 2.5 3.5NC 13,980 12,737 1,243 3.505% 2.599% 12.792% 0.73 0.73 1 1.9 2.1 1.7 6.75 9.2 3.4 63 63 21ND 444 371 73 7.207% 6.469% 10.959% 1.04 1.04 1.11 1.885 1.95 1.66 3.14 3.19 2.84 3.55 3.55 2.84NE 2,220 2,143 77 0.135% 0.140% 0.000% 2.09 2.09 2.35 2.35 8.7 8.7 8.7 8.7NHNJ 3 3 0 0.000% 0.000% 0.000%NM 4,174 3,941 233 0.048% 0.025% 0.429% 2.1 2.1 4 3.05 2.1 4 4 2.1 4 4 2.1 4NV 1,584 1,162 422 0.126% 0.172% 0.000% 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4NY 2,873 2,162 711 0.139% 0.139% 0.141% 0.18 3 0.18 16.5 30 0.18 51 51 0.18 51 51 0.18OH 145 55 90 0.690% 0.000% 1.111% 19.1 19.1 19.1 19.1 19.1 19.1 19.1 19.1OKOR 2,057 1,571 486 0.097% 0.000% 0.412% 4 4 15 15 26 26 26 26RI 627 413 214 0.000% 0.000% 0.000%SC 2,545 2,255 290 0.039% 0.044% 0.000% 24 24 24 24 24 24 24 24SD 952 842 110 0.000% 0.000% 0.000%TN 62 12 50 4.839% 0.000% 6.000% 1.6 1.6 2 2 83 83 83 83TX 2,174 1,343 831 0.000% 0.000% 0.000%UT 7,082 5,899 1,183 0.000% 0.000% 0.000%VA 442 148 294 0.000% 0.000% 0.000%VT 41 40 1 0.000% 0.000% 0.000%WI 3,161 3,069 92 0.158% 0.163% 0.000% 0.23 0.23 0.5 0.5 1.3 1.3 1.3 1.3WV 645 338 307 1.860% 2.367% 1.303% 0.06 0.06 0.06 0.07 0.07 0.28 111111WY 1,253 940 313 0.160% 0.106% 0.319% 2 10 2 6 10 2 10 10 2 10 10 2Total 112,423 88,908 23,515 0.978% 0.733% 1.905% 0.01 0.01 0.04 1.6 1.7 1.4 5 6.6 3.2 1210 1210 83

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A18b. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 18 13 5 316,254 84,804 231,450 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 184 128 56 2,877,453 597,317 2,280,136 2.174% 1.563% 3.571% 1.789% 0.437% 2.144%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 917 869 48 6,033,847 2,663,256 3,370,591 0.763% 0.345% 8.333% 18.957% 3.534% 31.144%CA 1,580 1,259 321 33,369,613 12,021,601 21,348,012 0.316% 0.159% 0.935% 1.578% 0.117% 2.401%CO 816 597 219 4,994,023 527,114 4,466,909 0.858% 0.670% 1.370% 0.082% 0.112% 0.078%CT 652 615 37 2,588,913 261,646 2,327,267 0.460% 0.325% 2.703% 2.488% 0.185% 2.747%DE 254 251 3 624,615 343,215 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,329 1,307 22 16,800,741 14,558,736 2,242,005 3.988% 3.979% 4.545% 17.841% 19.502% 7.059%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 1,056 1,023 33 2,543,237 1,434,611 1,108,626 0.473% 0.098% 12.121% 5.780% 0.014% 13.241%ID 857 804 53 1,052,182 802,078 250,104 0.117% 0.124% 0.000% 0.005% 0.007% 0.000%IL 1,121 1,020 101 9,097,009 2,901,087 6,195,922 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,404 1,360 44 4,871,546 2,551,810 2,319,736 0.499% 0.368% 4.545% 3.867% 0.449% 7.628%KY 241 92 149 4,596,328 369,299 4,227,029 8.714% 0.000% 14.094% 23.025% 0.000% 25.036%MA 645 528 117 8,509,903 1,707,521 6,802,382 0.930% 0.568% 2.564% 1.604% 1.395% 1.656%MD 862 794 68 4,906,001 907,894 3,998,107 12.761% 8.690% 60.294% 83.252% 14.136% 98.947%ME 216 190 26 491,237 116,848 374,389 0.463% 0.000% 3.846% 0.578% 0.000% 0.759%MI 511 458 53 5,833,684 1,208,759 4,624,925 1.566% 0.218% 13.208% 2.448% 0.984% 2.830%MN 1,281 1,252 29 3,931,386 2,681,745 1,249,641 2.030% 1.757% 13.793% 3.356% 4.099% 1.761%MO 1,475 1,398 77 3,281,888 1,700,557 1,581,331 0.678% 0.715% 0.000% 0.851% 1.642% 0.000%MT 846 786 60 757,811 365,142 392,669 0.473% 0.254% 3.333% 0.075% 0.068% 0.080%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 8.203% 7.451% 20.438% 36.942% 39.471% 36.091%ND 209 182 27 559,198 253,973 305,225 7.656% 4.945% 25.926% 12.899% 3.046% 21.098%NE 739 728 11 1,454,673 678,193 776,480 0.406% 0.412% 0.000% 0.561% 1.203% 0.000%NHNJ 2 2 0 8,623 8,623 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 673 639 34 1,652,427 1,391,779 260,648 0.297% 0.156% 2.941% 0.009% 0.008% 0.012%NV 287 266 21 960,268 270,377 689,891 0.697% 0.752% 0.000% 0.034% 0.120% 0.000%NY 1,345 1,115 230 4,923,849 982,159 3,941,690 0.223% 0.179% 0.435% 0.350% 0.579% 0.293%OH 37 28 9 3,029,193 99,582 2,929,611 2.703% 0.000% 11.111% 0.599% 0.000% 0.619%OKOR 1,086 936 150 2,937,289 572,539 2,364,750 0.092% 0.000% 0.667% 0.006% 0.000% 0.007%RI 88 79 9 900,541 160,563 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 728 676 52 3,300,197 782,848 2,517,349 0.137% 0.148% 0.000% 0.002% 0.009% 0.000%SD 260 239 21 622,152 262,981 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 11 5 6 648,720 144,963 503,757 18.182% 0.000% 33.333% 28.360% 0.000% 36.521%TX 856 702 154 18,700,247 4,013,688 14,686,559 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,671 1,667,485 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 173 63 110 2,380,983 26,904 2,354,079 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 34 33 1 96,146 27,223 68,923 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WI 1,406 1,386 20 3,883,613 2,191,869 1,691,744 0.284% 0.289% 0.000% 0.325% 0.575% 0.000%WV 342 197 145 1,367,674 206,326 1,161,348 2.924% 4.061% 1.379% 0.576% 0.827% 0.532%WY 304 256 48 446,177 129,229 316,948 0.658% 0.391% 2.083% 2.270% 0.542% 2.975%Total 28,387 25,558 2,829 178,186,111 64,625,469 113,560,642 1.828% 1.471% 5.055% 7.623% 6.168% 8.451%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A18c. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.068% 0.072% 0.000% 20,114 20,114 0 0.613% 1.183% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 1 0 0.004% 0.004% 0.000% 20,114 20,114 0 0.011% 0.031% 0.000%

Percent of Population Served 

with At Least One Detection 

> 200 μg/L

State

Number of Systems 

with At Least One Detection 

> 200 μg/L

Percent of Systems 

with At Least One Detection 

> 200 μg/L

Population Served by Systems 

with At Least One Detection 

> 200 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A18d. Dalapon – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.068% 0.072% 0.000% 20,114 20,114 0 0.613% 1.183% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 1 0 0.004% 0.004% 0.000% 20,114 20,114 0 0.011% 0.031% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 400 μg/L 25,891 2 0.008% 65,031,810 22,913 0.035%	
 25,891 7 0.027% 65,031,810 24,953 0.038%> 400 μg/L 3,011 0 0.000% 119,102,864 0 0.000%

	
 3,011 0 0.000% 119,102,864 0 0.000%

> 400 μg/L 28,902 2 0.007% 184,134,674 22,913 0.012%	
 28,902 7 0.024% 184,134,674 24,953 0.014%

Ground Water

Surface Water

Combined Ground & 

Surface Water

Table A19. Di(2-ethlyhexyl)adipate (DEHA) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 50 16 34 4.000% 0.000% 5.882% 0.17 0.17 0.24 0.24 0.31 0.31 0.31 0.31AL 746 492 254 0.536% 0.000% 1.575% 0.13 0.13 2.75 2.75 43.7 43.7 43.7 43.7AR 2,241 1,923 318 0.312% 0.364% 0.000% 0.8 0.8 1.62 1.62 3.24 3.24 3.24 3.24AZ 7,000 5,461 1,539 0.086% 0.110% 0.000% 0.87 0.87 0.87 0.87 3 3 3 3CA 12,867 7,353 5,514 0.078% 0.122% 0.018% 0.23 0.23 7.4 1.1 1.1 7.4 7.65 7.9 7.4 7.9 7.9 7.4CO 2,541 1,834 707 0.630% 0.763% 0.283% 0.16 0.16 0.84 0.95 0.95 2.47 2.4 1.8 4.1 4.1 2.4 4.1CT 1,320 1,010 310 1.288% 1.683% 0.000% 1 1 1 1 1.32 1.32 1.32 1.32DE 1,084 1,054 30 0.092% 0.095% 0.000% 2 2 2 2 2 2 2 2FL 2,476 2,407 69 0.727% 0.748% 0.000% 0.01 0.01 0.01 0.01 0.48 0.48 1.1 1.1GA 1,469 1,389 80 0.000% 0.000% 0.000%HIIA 1,757 1,627 130 0.512% 0.553% 0.000% 0.6 0.6 1.7 1.7 88 88 88 88ID 2,718 2,424 294 0.074% 0.083% 0.000% 4.6 4.6 5.5 5.5 6.4 6.4 6.4 6.4IL 3,857 3,106 751 0.000% 0.000% 0.000%IN 2,299 2,101 198 0.391% 0.428% 0.000% 0.37 0.37 0.84 0.84 7 7 7 7KY 2,186 571 1,615 0.457% 0.175% 0.557% 0.5 1300 0.5 0.95 1300 0.6 655 1300 10 1300 1300 10MA 3,074 2,260 814 1.952% 1.372% 3.563% 0.4 0.48 0.4 0.815 0.83 0.8 2.115 1.73 3.15 5 5 4.9MD 2,816 1,729 1,087 3.693% 2.140% 6.164% 0.03 0.5 0.03 0.7 0.6 0.7 1.9 1.7 2.1 25.3 6.9 25.3ME 456 391 65 0.219% 0.000% 1.538% 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19MI 309 181 128 0.647% 0.552% 0.781% 1.2 2.2 1.2 1.7 2.2 1.2 2.2 2.2 1.2 2.2 2.2 1.2MN 4,761 4,620 141 0.084% 0.087% 0.000% 7.1 7.1 7.95 7.95 11 11 11 11MO 324 194 130 0.000% 0.000% 0.000%MT 2,990 2,692 298 0.201% 0.223% 0.000% 0.51 0.51 0.835 0.835 7.4 7.4 7.4 7.4NC 13,804 12,708 1,096 1.681% 1.660% 1.916% 0.11 0.11 0.65 1.025 1.02 1.26 2.58 2.47 3.57 17 17 5.08ND 65 42 23 0.000% 0.000% 0.000%NE 4,480 4,131 349 0.134% 0.121% 0.287% 0.57 0.57 4.81 1.62 0.94 4.81 5.6 5.6 4.81 5.6 5.6 4.81NH 4,194 3,874 320 0.072% 0.052% 0.313% 0.6 0.6 4.4 2.3 1.45 4.4 4.4 2.3 4.4 4.4 2.3 4.4NJ 40 33 7 10.000% 12.121% 0.000% 0.02 0.02 0.07 0.07 0.26 0.26 0.26 0.26NM 4,565 4,302 263 3.067% 3.208% 0.760% 0.01 0.01 1.12 0.39 0.29 1.17 107 107 1.22 1000 1000 1.22NV 1,610 1,180 430 0.124% 0.085% 0.233% 2.6 2.6 5.43 4.015 2.6 5.43 5.43 2.6 5.43 5.43 2.6 5.43NY 2,781 2,055 726 0.108% 0.000% 0.413% 0.63 0.63 1.4 1.4 2 2 2 2OH 886 641 245 0.226% 0.312% 0.000% 0.8 0.8 1.24 1.24 1.68 1.68 1.68 1.68OKOR 2,054 1,570 484 0.000% 0.000% 0.000%RI 916 624 292 0.437% 0.641% 0.000% 3.2 3.2 4 4 52 52 52 52SC 2,966 2,572 394 0.169% 0.194% 0.000% 0.64 0.64 0.74 0.74 1.42 1.42 1.42 1.42SD 956 847 109 0.000% 0.000% 0.000%TN 63 10 53 1.587% 0.000% 1.887% 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6TX 10,273 4,527 5,746 0.195% 0.110% 0.261% 2.29 2.59 2.29 2.77 3.32 2.75 4.84 4.87 3.93 4.87 4.87 4.81UT 7,096 5,913 1,183 0.296% 0.321% 0.169% 0.09 0.09 0.1 0.6 0.6 0.35 3.3 3.3 0.6 4.4 4.4 0.6VA 495 181 314 0.404% 1.105% 0.000% 0.4 0.4 0.65 0.65 0.9 0.9 0.9 0.9VT 1,321 1,120 201 0.227% 0.268% 0.000% 0.3 0.3 1.18 1.18 4.91 4.91 4.91 4.91WI 1,965 1,888 77 0.254% 0.265% 0.000% 0.7 0.7 40 40 40 40 40 40WV 642 335 307 1.869% 2.388% 1.303% 0.02 0.15 0.02 0.15 0.175 0.15 0.2 0.2 0.5 0.5 0.2 0.5WY 1,279 963 316 0.469% 0.623% 0.000% 0.5 0.5 0.745 0.745 0.9 0.9 0.9 0.9Total 121,792 94,351 27,441 0.623% 0.627% 0.609% 0.01 0.01 0.02 0.91 0.935 0.8 8.2 15.13 4.1 1300 1300 43.7Table A19a. Di(2-ethlyhexyl)adipate (DEHA) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A19b. Di(2-ethlyhexyl)adipate (DEHA) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 11 6 5 245,546 13,611 231,935 18.182% 0.000% 40.000% 1.528% 0.000% 1.618%AL 187 138 49 3,622,176 774,145 2,848,031 1.604% 0.000% 6.122% 7.237% 0.000% 9.204%AR 454 382 72 2,453,348 910,322 1,543,026 1.542% 1.832% 0.000% 0.305% 0.821% 0.000%AZ 931 883 48 6,077,279 2,706,688 3,370,591 0.322% 0.340% 0.000% 0.321% 0.722% 0.000%CA 1,271 1,032 239 33,445,493 11,991,296 21,454,197 0.472% 0.484% 0.418% 1.391% 1.619% 1.263%CO 799 581 218 4,983,566 519,647 4,463,919 1.877% 2.238% 0.917% 0.273% 1.216% 0.164%CT 651 614 37 2,588,823 261,556 2,327,267 2.458% 2.606% 0.000% 0.277% 2.745% 0.000%DE 231 228 3 632,320 350,920 281,400 0.433% 0.439% 0.000% 0.058% 0.105% 0.000%FL 1,334 1,312 22 16,773,387 14,531,382 2,242,005 0.750% 0.762% 0.000% 15.843% 18.288% 0.000%GA 287 273 14 973,497 281,475 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 1,056 1,023 33 2,543,237 1,434,611 1,108,626 0.852% 0.880% 0.000% 0.330% 0.586% 0.000%ID 915 858 57 1,090,586 834,621 255,965 0.219% 0.233% 0.000% 0.029% 0.038% 0.000%IL 1,085 987 98 9,086,128 2,892,050 6,194,078 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,401 1,357 44 4,866,289 2,546,553 2,319,736 0.214% 0.221% 0.000% 0.339% 0.648% 0.000%KY 242 93 149 4,602,489 375,460 4,227,029 3.306% 1.075% 4.698% 8.230% 0.506% 8.916%MA 642 525 117 8,482,868 1,680,486 6,802,382 5.140% 4.571% 7.692% 6.057% 7.423% 5.720%MD 862 794 68 4,906,096 907,989 3,998,107 7.889% 4.534% 47.059% 80.246% 11.547% 95.848%ME 269 241 28 510,420 134,500 375,920 0.372% 0.000% 3.571% 26.830% 0.000% 36.429%MI 89 62 27 5,100,237 379,121 4,721,116 2.247% 1.613% 3.704% 0.305% 0.034% 0.327%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.311% 0.318% 0.000% 0.363% 0.531% 0.000%MO 226 157 69 928,947 284,141 644,806 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.615% 0.664% 0.000% 0.065% 0.135% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 6.385% 6.104% 10.949% 4.397% 9.181% 2.787%ND 27 21 6 47,590 40,561 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.656% 0.533% 9.091% 35.365% 0.397% 65.960%NH 1,237 1,196 41 945,754 395,955 549,799 0.243% 0.167% 2.439% 1.454% 0.631% 2.046%NJ 36 30 6 1,444,605 143,223 1,301,382 11.111% 13.333% 0.000% 3.959% 39.936% 0.000%NM 694 658 36 1,661,813 1,398,915 262,898 12.248% 12.614% 5.556% 50.494% 54.780% 27.692%NV 294 273 21 961,367 271,476 689,891 0.680% 0.366% 4.762% 5.946% 0.243% 8.190%NY 1,262 1,042 220 4,867,369 949,158 3,918,211 0.158% 0.000% 0.909% 0.095% 0.000% 0.118%OH 315 239 76 6,613,224 638,627 5,974,597 0.635% 0.837% 0.000% 0.013% 0.137% 0.000%OKOR 1,083 933 150 2,936,954 572,204 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 105 97 8 902,560 163,122 739,438 3.810% 4.124% 0.000% 3.166% 17.518% 0.000%SC 773 714 59 3,427,802 801,019 2,626,783 0.517% 0.560% 0.000% 0.134% 0.574% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 11 5 6 655,064 144,562 510,502 9.091% 0.000% 16.667% 27.642% 0.000% 35.470%TX 1,883 1,546 337 21,494,935 5,731,435 15,763,500 0.637% 0.259% 2.374% 8.657% 0.690% 11.554%UT 426 389 37 2,500,671 1,667,485 833,186 3.286% 3.085% 5.405% 4.239% 5.966% 0.783%VA 178 69 109 2,179,119 28,420 2,150,699 0.562% 1.449% 0.000% 0.009% 0.658% 0.000%VT 441 408 33 432,879 181,715 251,164 0.680% 0.735% 0.000% 1.177% 2.805% 0.000%WI 1,063 1,044 19 3,694,549 2,037,305 1,657,244 0.188% 0.192% 0.000% 0.407% 0.738% 0.000%WV 339 195 144 1,358,636 205,538 1,153,098 2.950% 4.103% 1.389% 0.678% 0.806% 0.656%WY 304 256 48 446,177 129,229 316,948 1.316% 1.563% 0.000% 0.083% 0.286% 0.000%Total 28,902 25,891 3,011 184,134,674 65,031,810 119,102,864 1.754% 1.599% 3.089% 6.767% 6.686% 6.811%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A19c. Di(2-ethlyhexyl)adipate (DEHA) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 1 0 0.413% 1.075% 0.000% 1,898 1,898 0 0.041% 0.506% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 1 1 0 0.144% 0.152% 0.000% 21,015 21,015 0 1.265% 1.502% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 2 0 0.007% 0.008% 0.000% 22,913 22,913 0 0.012% 0.035% 0.000%

Percent of Population Served 

with At Least One Detection 

> 400 μg/L

State

Number of Systems 

with At Least One Detection 

> 400 μg/L

Percent of Systems 

with At Least One Detection 

> 400 μg/L

Population Served by Systems 

with At Least One Detection 

> 400 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 1 0 0.413% 1.075% 0.000% 1,898 1,898 0 0.041% 0.506% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 6 6 0 0.865% 0.912% 0.000% 23,055 23,055 0 1.387% 1.648% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 7 7 0 0.024% 0.027% 0.000% 24,953 24,953 0 0.014% 0.038% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	


Table A19d. Di(2-ethlyhexyl)adipate (DEHA) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 6 μg/L 24,677 390 1.580% 62,976,862 2,513,952 3.992%

	
 24,677 786 3.185% 62,976,862 5,407,270 8.586%

> 6 μg/L 2,990 70 2.341% 116,971,710 8,996,752 7.691%

	
 2,990 169 5.652% 116,971,710 19,734,540 16.871%> 6 μg/L 27,667 460 1.663% 179,948,572 11,510,704 6.397%

	
 27,667 955 3.452% 179,948,572 25,141,810 13.972%

Ground Water

Surface Water

Combined Ground & 

Surface Water

Table A20. Di(2-ethylhexyl)phthalate (DEHP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 50 16 34 0.000% 0.000% 0.000%AL 1,225 886 339 15.347% 15.237% 15.634% 0.06 0.06 0.06 0.2 0.18 0.22 2 2.67 0.7 33.5 33.5 3AR 2,242 1,924 318 3.390% 3.482% 2.830% 1.34 1.34 1.5 1.89 1.88 2.28 4.5 4.27 9.54 16.5 16.5 9.54AZ 6,772 5,213 1,559 4.090% 3.568% 5.837% 0.5 0.6 0.5 1 1 1 4.2 3.9 4.5 38 20 38CA 13,156 7,455 5,701 0.676% 0.604% 0.772% 0.14 0.14 0.22 3 3.82 1.4 13 15 9.3 49 49 25CO 2,651 1,912 739 8.487% 8.577% 8.254% 0.21 0.21 0.28 1.04 1.1 1 2.4 2.4 2.1 14 14 8.9CT 1,323 1,013 310 2.948% 3.455% 1.290% 0.4 0.4 2 1 1 5.5 7 3 11 53 53 11DE 790 766 24 3.038% 3.133% 0.000% 0.5 0.5 1.5 1.5 6.4 6.4 7.9 7.9FL 2,638 2,563 75 4.397% 4.331% 6.667% 0.14 0.14 0.6 0.75 0.75 0.72 3.4 3.1 13 27.8 27.8 13GA 1,468 1,388 80 0.204% 0.072% 2.500% 5.2 5.2 6.6 6.6 5.2 6.6 6.6 5.2 6.6 6.6 5.2 6.6HIIA 1,800 1,667 133 2.444% 2.340% 3.759% 0.6 0.6 0.6 1.75 1.8 0.9 13.9 13.9 18 53 53 18ID 2,733 2,439 294 3.000% 3.198% 1.361% 0.12 0.12 0.9 1.6 1.58 5.75 5.3 4.52 9.8 9.8 8.6 9.8IL 3,917 3,114 803 0.332% 0.417% 0.000% 0.9 0.9 4.6 4.6 9.2 9.2 10 10IN 2,360 2,150 210 3.263% 3.209% 3.810% 0.57 0.6 0.57 1.25 1.29 0.965 4.53 4.53 5.6 25 25 5.6KY 2,259 584 1,675 13.015% 13.356% 12.896% 0.1 0.1 0.1 1.5 1.6 1.5 3.5 3.7 3.5 40 40 13MA 3,088 2,271 817 3.854% 3.082% 5.998% 0.3 0.42 0.3 0.93 1 0.89 3.8 4.7 2.8 51.3 51.3 5.1MD 2,811 1,727 1,084 63.429% 72.032% 49.723% 0.1 0.1 0.1 1 0.95 1 3.8 3.9 3.4 38.3 29 38.3ME 456 391 65 13.158% 11.253% 24.615% 0.06 0.06 0.13 0.245 0.3 0.21 3 3 0.35 14 12 14MI 263 135 128 11.787% 13.333% 10.156% 1 1 1 1.2 1.3 1.1 2.1 2.1 3883MN 4,761 4,620 141 3.004% 2.922% 5.674% 0.07 0.07 4.2 8.7 8.8 6.8 21 21 49 54 54 49MO 304 181 123 0.000% 0.000% 0.000%MT 3,047 2,749 298 3.446% 3.565% 2.349% 0.6 0.6 0.76 2.82 2.8 7.8 10 9.6 10 35 35 10NC 13,796 12,703 1,093 2.276% 2.377% 1.098% 0.6 0.6 0.8 2.1 2.1 1.965 5.04 5.1 3.54 22.09 22.09 3.8ND 64 41 23 43.750% 39.024% 52.174% 0.6 0.6 0.6 0.985 0.96 1.075 2.63 2.02 2.63 3.75 3.5 3.75NE 4,480 4,131 349 2.232% 2.348% 0.860% 2 2 2.2 3.445 3.5 2.78 9.165 8.93 9.5 19.6 19.6 9.5NH 4,243 3,924 319 4.101% 4.332% 1.254% 0.06 0.06 1.2 2.4 2.4 4.15 8.1 8.4 4.9 47 47 4.9NJ 30 28 2 16.667% 17.857% 0.000% 0.36 0.36 0.39 0.39 1.1 1.1 1.1 1.1NM 4,437 4,178 259 13.094% 13.308% 9.653% 0.05 0.05 0.07 0.4 0.4 0.5 5.24 5.24 2.28 56.76 56.76 15.11NV 1,569 1,141 428 2.804% 3.067% 2.103% 0.31 0.31 0.71 1.6 1.3 4 5.2 5 46.4 46.4 21 46.4NY 2,800 2,075 725 1.857% 1.590% 2.621% 0.62 0.62 0.64 2.5 2.2 2.8 10.5 10.5 11 39 39 12OH 1,102 834 268 5.172% 5.396% 4.478% 0.2 0.2 0.63 1.5 1.42 1.65 4.75 4.75 5.4 31 16.6 31OKOR 2,095 1,581 514 1.289% 1.392% 0.973% 0.08 0.08 1.3 1.9 1.65 1.9 5.1 3.3 5.2 250 250 5.2RI 917 625 292 5.889% 4.640% 8.562% 0.42 1 0.42 1.45 1.8 0.87 4 4.4 2.9 20 20 4SC 2,965 2,572 393 10.995% 11.275% 9.160% 0.11 0.11 0.64 1.24 1.22 1.34 6.86 6.955 6 43 39 43SD 959 850 109 0.104% 0.118% 0.000% 4 4 4 4 4 4 4 4TN 64 10 54 6.250% 0.000% 7.407% 0.7 0.7 1.1 1.1 4.8 4.8 4.8 4.8TX 10,362 4,571 5,791 0.984% 1.072% 0.915% 2.1 2.1 2.1 3.87 4.19 3.7 11 10.79 11 26 18.3 26UT 7,103 5,915 1,188 1.197% 1.319% 0.589% 0.15 0.15 0.9 2 2 1.9 6.6 6.6 2.7 11 11 2.7VA 494 180 314 3.644% 8.889% 0.637% 0.8 0.8 2.3 1.8 1.8 3 7.3 7.3 3.7 16 16 3.7VT 1,313 1,112 201 3.046% 2.788% 4.478% 0.08 0.08 0.6 0.855 0.8 0.9 5.35 4.2 13.1 43.7 43.7 13.1WIWV 653 340 313 9.648% 10.294% 8.946% 0.18 0.18 0.18 1.2 1.1 1.2 2 2 2 6 6 3.9WY 1,286 969 317 5.443% 5.882% 4.101% 0.5 0.5 0.6 2.8 2.7 3 9 8 10 38 38 20Total 120,846 92,944 27,902 4.910% 4.864% 5.061% 0.05 0.05 0.06 1.2 1.3 1.1 5.8 6.26 4.4 250 250 49Table A20a. Di(2-ethylhexyl)phthalate (DEHP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Maximum Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L) Median Detect Concentration (μg/L) 90th Percentile Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 11 6 5 245,546 13,611 231,935 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 224 164 60 3,940,846 920,969 3,019,877 25.000% 23.780% 28.333% 23.303% 28.374% 21.757%AR 454 382 72 2,453,348 910,322 1,543,026 10.573% 11.518% 5.556% 6.518% 13.819% 2.211%AZ 827 782 45 5,930,120 2,573,109 3,357,011 12.092% 10.486% 40.000% 78.556% 54.585% 96.929%CA 1,217 983 234 33,392,382 11,920,793 21,471,589 4.191% 3.154% 8.547% 16.886% 6.138% 22.854%CO 799 581 218 4,983,566 519,647 4,463,919 20.150% 19.793% 21.101% 48.919% 29.248% 51.209%CT 652 615 37 2,589,440 262,173 2,327,267 5.368% 5.366% 5.405% 3.370% 3.429% 3.363%DE 217 214 3 619,324 337,924 281,400 6.912% 7.009% 0.000% 13.261% 24.303% 0.000%FL 1,354 1,331 23 16,824,422 14,581,030 2,243,392 4.801% 4.583% 17.391% 19.475% 20.263% 14.353%GA 287 273 14 973,497 281,475 692,022 0.697% 0.366% 7.143% 0.282% 0.025% 0.386%HIIA 1,057 1,024 33 2,543,282 1,434,656 1,108,626 3.311% 3.027% 12.121% 9.649% 5.125% 15.504%ID 915 857 58 1,090,891 834,529 256,362 6.120% 6.184% 5.172% 26.050% 11.725% 72.681%IL 1,085 987 98 9,086,128 2,892,050 6,194,078 1.014% 1.114% 0.000% 0.498% 1.565% 0.000%IN 1,400 1,356 44 4,866,255 2,546,519 2,319,736 4.071% 3.909% 9.091% 1.915% 2.303% 1.488%KY 242 93 149 4,602,489 375,460 4,227,029 51.240% 44.086% 55.705% 74.807% 29.933% 78.792%MA 642 525 117 8,482,938 1,680,556 6,802,382 9.969% 8.000% 18.803% 11.135% 13.505% 10.549%MD 861 793 68 4,906,036 907,929 3,998,107 88.734% 88.146% 95.588% 98.786% 93.833% 99.911%ME 269 241 28 510,420 134,500 375,920 17.100% 14.523% 39.286% 60.039% 49.017% 63.983%MI 50 23 27 5,093,160 372,044 4,721,116 34.000% 30.435% 37.037% 76.463% 30.942% 80.050%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 9.402% 9.221% 17.241% 29.328% 20.559% 48.166%MO 218 149 69 920,994 276,188 644,806 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 7.134% 7.304% 5.000% 5.809% 7.391% 4.357%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 8.710% 8.842% 6.569% 15.336% 25.182% 12.023%ND 27 21 6 47,590 40,561 7,029 62.963% 52.381% 100.000% 58.594% 51.419% 100.000%NE 762 751 11 1,455,834 679,354 776,480 7.087% 6.791% 27.273% 11.955% 20.646% 4.352%NH 1,237 1,196 41 945,754 395,955 549,799 6.952% 6.940% 7.317% 14.493% 17.507% 12.323%NJ 27 26 1 818,502 142,248 676,254 18.519% 19.231% 0.000% 3.075% 17.696% 0.000%NM 680 646 34 1,653,619 1,391,521 262,098 32.353% 32.198% 35.294% 66.472% 70.291% 46.196%NV 266 245 21 954,770 264,879 689,891 9.398% 9.388% 9.524% 9.596% 10.123% 9.393%NY 1,261 1,042 219 4,834,269 949,158 3,885,111 3.172% 2.687% 5.479% 15.701% 3.061% 18.790%OH 355 278 77 6,650,006 667,733 5,982,273 12.394% 13.309% 9.091% 3.583% 19.677% 1.786%OKOR 1,084 934 150 2,937,354 572,604 2,364,750 2.214% 2.141% 2.667% 2.628% 4.190% 2.250%RI 105 97 8 902,560 163,122 739,438 18.095% 14.433% 62.500% 42.255% 49.531% 40.650%SC 773 714 59 3,427,802 801,019 2,626,783 28.461% 27.871% 35.593% 31.613% 45.253% 27.454%SD 261 240 21 622,272 263,101 359,171 0.383% 0.417% 0.000% 0.032% 0.076% 0.000%TN 11 5 6 655,064 144,562 510,502 18.182% 0.000% 33.333% 36.497% 0.000% 46.832%TX 1,884 1,547 337 21,497,842 5,734,342 15,763,500 4.352% 2.780% 11.573% 28.512% 23.761% 30.240%UT 426 389 37 2,500,671 1,667,485 833,186 8.216% 7.455% 16.216% 33.198% 24.026% 51.554%VA 178 69 109 2,179,119 28,420 2,150,699 3.933% 7.246% 1.835% 4.403% 7.590% 4.361%VT 441 408 33 432,879 181,715 251,164 7.483% 6.373% 21.212% 22.029% 19.399% 23.932%WIWV 339 195 144 1,358,636 205,538 1,153,098 14.454% 14.359% 14.583% 17.911% 12.385% 18.896%WY 304 256 48 446,177 129,229 316,948 14.145% 14.844% 10.417% 10.877% 14.295% 9.484%Total 27,667 24,677 2,990 179,948,572 62,976,862 116,971,710 11.197% 10.577% 16.321% 25.227% 19.240% 28.450%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting

Table A20b. Di(2-ethylhexyl)phthalate (DEHP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 4 4 0 1.786% 2.439% 0.000% 41,247 41,247 0 1.047% 4.479% 0.000%AR 5 3 2 1.101% 0.785% 2.778% 25,941 8,152 17,789 1.057% 0.896% 1.153%AZ 13 8 5 1.572% 1.023% 11.111% 3,307,784 724,702 2,583,082 55.779% 28.164% 76.946%CA 16 9 7 1.315% 0.916% 2.991% 2,291,146 156,205 2,134,941 6.861% 1.310% 9.943%CO 3 2 1 0.375% 0.344% 0.459% 910 160 750 0.018% 0.031% 0.017%CT 4 2 2 0.613% 0.325% 5.405% 78,588 324 78,264 3.035% 0.124% 3.363%DE 4 4 0 1.843% 1.869% 0.000% 69,242 69,242 0 11.180% 20.490% 0.000%FL 4 3 1 0.295% 0.225% 4.348% 161,293 128,294 32,999 0.959% 0.880% 1.471%GA 1 0 1 0.348% 0.000% 7.143% 2,671 0 2,671 0.274% 0.000% 0.386%HIIA 8 7 1 0.757% 0.684% 3.030% 15,307 15,282 25 0.602% 1.065% 0.002%ID 5 3 2 0.546% 0.350% 3.448% 186,706 680 186,026 17.115% 0.081% 72.564%IL 4 4 0 0.369% 0.405% 0.000% 3,085 3,085 0 0.034% 0.107% 0.000%IN 2 2 0 0.143% 0.147% 0.000% 570 570 0 0.012% 0.022% 0.000%KY 6 3 3 2.479% 3.226% 2.013% 92,925 4,312 88,613 2.019% 1.148% 2.096%MA 4 4 0 0.623% 0.762% 0.000% 32,155 32,155 0 0.379% 1.913% 0.000%MD 75 57 18 8.711% 7.188% 26.471% 1,987,374 37,563 1,949,811 40.509% 4.137% 48.768%ME 4 3 1 1.487% 1.245% 3.571% 30,506 543 29,963 5.977% 0.404% 7.971%MI 1 1 0 2.000% 4.348% 0.000% 450 450 0 0.009% 0.121% 0.000%MN 91 87 4 7.071% 6.916% 13.793% 962,620 452,520 510,100 24.467% 16.856% 40.820%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 17 16 1 2.091% 2.125% 1.667% 20,866 3,871 16,995 2.770% 1.074% 4.328%NC 17 17 0 0.719% 0.763% 0.000% 18,874 18,874 0 0.274% 1.089% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 17 16 1 2.231% 2.130% 9.091% 76,704 76,311 393 5.269% 11.233% 0.051%NH 19 19 0 1.536% 1.589% 0.000% 6,493 6,493 0 0.687% 1.640% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 41 40 1 6.029% 6.192% 2.941% 603,565 603,513 52 36.500% 43.371% 0.020%NV 3 2 1 1.128% 0.816% 4.762% 56,672 172 56,500 5.936% 0.065% 8.190%NY 11 8 3 0.872% 0.768% 1.370% 285,133 9,551 275,582 5.898% 1.006% 7.093%OH 4 3 1 1.127% 1.079% 1.299% 8,151 4,863 3,288 0.123% 0.728% 0.055%OKOR 1 1 0 0.092% 0.107% 0.000% 168 168 0 0.006% 0.029% 0.000%RI 1 1 0 0.952% 1.031% 0.000% 600 600 0 0.066% 0.368% 0.000%SC 35 34 1 4.528% 4.762% 1.695% 150,316 83,557 66,759 4.385% 10.431% 2.541%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 19 8 11 1.008% 0.517% 3.264% 961,169 20,810 940,359 4.471% 0.363% 5.965%UT 4 4 0 0.939% 1.028% 0.000% 855 855 0 0.034% 0.051% 0.000%VA 2 2 0 1.124% 2.899% 0.000% 880 880 0 0.040% 3.096% 0.000%VT 4 3 1 0.907% 0.735% 3.030% 6,366 476 5,890 1.471% 0.262% 2.345%WIWV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 11 10 1 3.618% 3.906% 2.083% 23,372 7,472 15,900 5.238% 5.782% 5.017%Total 460 390 70 1.663% 1.580% 2.341% 11,510,704 2,513,952 8,996,752 6.397% 3.992% 7.691%

Percent of Population Served 

with At Least One Detection 

> 6 μg/L

State

Number of Systems 

with At Least One Detection 

> 6 μg/L

Percent of Systems 

with At Least One Detection 

> 6 μg/L

Population Served by Systems 

with At Least One Detection 

> 6 μg/L

Table A20c. Di(2-ethylhexyl)phthalate (DEHP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 9 8 1 4.018% 4.878% 1.667% 90,893 69,959 20,934 2.306% 7.596% 0.693%AR 14 12 2 3.084% 3.141% 2.778% 41,539 23,750 17,789 1.693% 2.609% 1.153%AZ 23 16 7 2.781% 2.046% 15.556% 3,414,108 806,607 2,607,501 57.572% 31.348% 77.673%CA 36 20 16 2.958% 2.035% 6.838% 5,178,634 599,374 4,579,260 15.508% 5.028% 21.327%CO 11 7 4 1.377% 1.205% 1.835% 15,187 4,873 10,314 0.305% 0.938% 0.231%CT 6 4 2 0.920% 0.650% 5.405% 78,984 720 78,264 3.050% 0.275% 3.363%DE 8 8 0 3.687% 3.738% 0.000% 71,234 71,234 0 11.502% 21.080% 0.000%FL 9 8 1 0.665% 0.601% 4.348% 209,527 176,528 32,999 1.245% 1.211% 1.471%GA 2 1 1 0.697% 0.366% 7.143% 2,741 70 2,671 0.282% 0.025% 0.386%HIIA 10 9 1 0.946% 0.879% 3.030% 17,309 17,284 25 0.681% 1.205% 0.002%ID 16 13 3 1.749% 1.517% 5.172% 197,935 11,609 186,326 18.144% 1.391% 72.681%IL 6 6 0 0.553% 0.608% 0.000% 3,548 3,548 0 0.039% 0.123% 0.000%IN 8 7 1 0.571% 0.516% 2.273% 8,065 2,077 5,988 0.166% 0.082% 0.258%KY 34 10 24 14.050% 10.753% 16.107% 1,691,395 11,653 1,679,742 36.750% 3.104% 39.738%MA 13 11 2 2.025% 2.095% 1.709% 65,650 58,155 7,495 0.774% 3.460% 0.110%MD 171 136 35 19.861% 17.150% 51.471% 4,003,361 188,195 3,815,166 81.601% 20.728% 95.424%ME 7 6 1 2.602% 2.490% 3.571% 35,298 5,335 29,963 6.915% 3.967% 7.971%MI 3 1 2 6.000% 4.348% 7.407% 143,191 450 142,741 2.811% 0.121% 3.023%MN 120 115 5 9.324% 9.141% 17.241% 1,153,823 551,923 601,900 29.327% 20.558% 48.166%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 28 27 1 3.444% 3.586% 1.667% 30,498 13,503 16,995 4.049% 3.745% 4.328%NC 64 61 3 2.706% 2.738% 2.190% 309,915 182,164 127,751 4.501% 10.508% 2.480%ND 2 1 1 7.407% 4.762% 16.667% 3,604 196 3,408 7.573% 0.483% 48.485%NE 29 28 1 3.806% 3.728% 9.091% 122,111 121,718 393 8.388% 17.917% 0.051%NH 37 35 2 2.991% 2.926% 4.878% 98,437 34,187 64,250 10.408% 8.634% 11.686%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 77 75 2 11.324% 11.610% 5.882% 836,366 763,613 72,753 50.578% 54.876% 27.758%NV 7 6 1 2.632% 2.449% 4.762% 74,911 18,411 56,500 7.846% 6.951% 8.190%NY 20 13 7 1.586% 1.248% 3.196% 461,461 25,593 435,868 9.546% 2.696% 11.219%OH 15 13 2 4.225% 4.676% 2.597% 35,221 11,722 23,499 0.530% 1.755% 0.393%OKOR 6 4 2 0.554% 0.428% 1.333% 59,857 7,870 51,987 2.038% 1.374% 2.198%RI 4 3 1 3.810% 3.093% 12.500% 70,663 2,400 68,263 7.829% 1.471% 9.232%SC 56 53 3 7.245% 7.423% 5.085% 309,002 151,549 157,453 9.015% 18.920% 5.994%SD 1 1 0 0.383% 0.417% 0.000% 200 200 0 0.032% 0.076% 0.000%TN 1 0 1 9.091% 0.000% 16.667% 58,000 0 58,000 8.854% 0.000% 11.361%TX 57 30 27 3.025% 1.939% 8.012% 5,972,023 1,332,646 4,639,377 27.780% 23.240% 29.431%UT 10 10 0 2.347% 2.571% 0.000% 123,765 123,765 0 4.949% 7.422% 0.000%VA 3 2 1 1.685% 2.899% 0.917% 94,260 880 93,380 4.326% 3.096% 4.342%VT 6 5 1 1.361% 1.225% 3.030% 8,696 2,806 5,890 2.009% 1.544% 2.345%WIWV 2 1 1 0.590% 0.513% 0.694% 13,642 381 13,261 1.004% 0.185% 1.150%WY 24 20 4 7.895% 7.813% 8.333% 36,756 10,322 26,434 8.238% 7.987% 8.340%Total 955 786 169 3.452% 3.185% 5.652% 25,141,810 5,407,270 19,734,540 13.972% 8.586% 16.871%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	


Table A20d. Di(2-ethylhexyl)phthalate (DEHP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.2 μg/L 34,602 120 0.347% 73,552,992 1,032,709 1.404%

	
 34,602 168 0.486% 73,552,992 1,370,317 1.863%

> 0.2 μg/L 3,016 26 0.862% 120,196,347 2,118,782 1.763%

	
 3,016 33 1.094% 120,196,347 5,730,210 4.767%

> 0.2 μg/L 37,618 146 0.388% 193,749,339 3,151,491 1.627%

	
 37,618 201 0.534% 193,749,339 7,100,527 3.665%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water

Table A21. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 268 142 126 0.000% 0.000% 0.000%AL 634 465 169 2.839% 2.366% 4.142% 0.02 0.02 0.03 0.09 0.12 0.05 0.33 0.32 0.35 0.35 0.33 0.35AR 2,532 2,056 476 0.118% 0.146% 0.000% 0.04 0.04 0.2 0.2 0.53 0.53 0.53 0.53AZ 6,206 4,813 1,393 0.757% 0.748% 0.790% 0.01 0.02 0.01 0.04 0.065 0.02 0.12 0.12 0.06 0.5 0.25 0.5CA 58,699 31,660 27,039 32.846% 25.158% 41.847% 0.01 0.01 0.01 0.09 0.08 0.09 0.47 0.46 0.48 10.8 3.3 10.8CO 2,559 1,863 696 0.039% 0.000% 0.144% 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04CT 1,486 1,167 319 0.135% 0.086% 0.313% 0.02 0.07 0.02 0.045 0.07 0.02 0.07 0.07 0.02 0.07 0.07 0.02DE 2,309 2,247 62 0.043% 0.045% 0.000% 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03FL 2,394 2,329 65 0.794% 0.816% 0.000% 0.0014 0.0014 0.01 0.01 0.05 0.05 0.05 0.05GA 7,886 7,084 802 0.000% 0.000% 0.000%HI 3,057 2,966 91 5.954% 6.136% 0.000% 0.02 0.02 0.14 0.14 0.22 0.22 0.36 0.36IA 86 68 18 0.000% 0.000% 0.000%ID 1,800 1,579 221 0.000% 0.000% 0.000%IL 3,930 3,489 441 0.254% 0.201% 0.680% 0.02 0.02 0.03 0.02 0.02 0.03 0.125 0.08 0.17 0.17 0.08 0.17IN 2,262 2,089 173 0.044% 0.000% 0.578% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02KY 1,720 433 1,287 0.407% 0.000% 0.544% 0.01 0.01 0.02 0.02 0.2 0.2 0.2 0.2MA 2,944 2,163 781 0.102% 0.046% 0.256% 0.02 0.05 0.02 0.02 0.05 0.02 0.05 0.05 0.02 0.05 0.05 0.02MD 2,466 1,672 794 0.689% 0.359% 1.385% 0.009 0.04 0.009 0.05 0.085 0.04 0.12 0.12 0.12 0.13 0.12 0.13ME 2,184 2,026 158 0.000% 0.000% 0.000%MI 5,364 4,849 515 0.000% 0.000% 0.000%MN 8,585 7,336 1,249 0.000% 0.000% 0.000%MO 7,544 6,695 849 0.000% 0.000% 0.000%MT 1,197 1,081 116 0.000% 0.000% 0.000%NC 12,724 11,854 870 0.181% 0.194% 0.000% 0.01 0.01 0.03 0.03 0.08 0.08 0.6 0.6ND 70 45 25 0.000% 0.000% 0.000%NE 9,185 8,528 657 0.011% 0.012% 0.000% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02NH 4,043 3,874 169 0.000% 0.000% 0.000%NJ 19,688 18,239 1,449 0.061% 0.060% 0.069% 0.06 0.06 1 0.595 0.49 1 1.5 1.5 1 3.64 3.64 1NM 944 885 59 0.212% 0.226% 0.000% 0.003 0.003 0.0035 0.0035 0.004 0.004 0.004 0.004NV 2,404 1,891 513 0.042% 0.000% 0.195% 4.9 4.9 4.9 4.9 4.9 4.9 4.9 4.9NY 551 390 161 1.815% 2.051% 1.242% 0.02 0.05 0.02 1.85 2.865 0.26 4.66 5.12 0.5 5.12 5.12 0.5OH 42 12 30 0.000% 0.000% 0.000%OKOR 2,049 1,566 483 0.098% 0.128% 0.000% 0.09 0.09 0.12 0.12 0.15 0.15 0.15 0.15RI 2,258 1,782 476 0.044% 0.000% 0.210% 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4SC 3,248 2,794 454 2.771% 2.577% 3.965% 0.02 0.02 0.09 0.22 0.1 0.31 0.5 0.5 0.5 0.51 0.5 0.51SD 1,493 1,367 126 0.000% 0.000% 0.000%TN 55 11 44 0.000% 0.000% 0.000%TX 34,144 27,040 7,104 0.009% 0.011% 0.000% 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6UT 13 13 0 7.692% 7.692% 0.000% 6.6 6.6 6.6 6.6 6.6 6.6 6.6 6.6VA 4,824 3,823 1,001 0.000% 0.000% 0.000%VT 435 377 58 0.000% 0.000% 0.000%WI 2,867 2,837 30 0.105% 0.106% 0.000% 0.01 0.01 0.01 0.01 0.2 0.2 0.2 0.2WV 694 361 333 1.585% 2.216% 0.901% 0.0028 0.0028 0.02 0.02 0.0114 0.02 0.5 1.3 0.5 1.3 1.3 0.5WY 1,326 997 329 0.000% 0.000% 0.000%Total 231,169 178,958 52,211 8.544% 4.675% 21.806% 0.0014 0.0014 0.009 0.09 0.08 0.09 0.47 0.46 0.48 10.8 6.6 10.8Table A21a. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 140 78 62 210,315 108,644 101,671 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 185 138 47 2,887,527 734,715 2,152,812 6.486% 5.797% 8.511% 7.028% 9.705% 6.114%AR 454 382 72 2,453,348 910,322 1,543,026 0.661% 0.785% 0.000% 1.322% 3.563% 0.000%AZ 931 883 48 6,054,727 2,684,136 3,370,591 1.719% 1.246% 10.417% 45.524% 7.946% 75.449%CA 2,090 1,796 294 34,488,472 12,817,660 21,670,812 11.196% 11.303% 10.544% 16.224% 16.586% 16.010%CO 815 596 219 4,992,761 527,877 4,464,884 0.123% 0.000% 0.457% 0.034% 0.000% 0.038%CT 711 673 38 2,608,625 274,738 2,333,887 0.281% 0.149% 2.632% 0.405% 2.704% 0.134%DE 332 329 3 707,346 425,946 281,400 0.301% 0.304% 0.000% 0.031% 0.052% 0.000%FL 1,311 1,290 21 16,789,423 14,550,247 2,239,176 0.992% 1.008% 0.000% 22.850% 26.366% 0.000%GA 1,763 1,648 115 7,452,538 1,559,757 5,892,781 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 109 97 12 1,300,349 1,245,721 54,628 4.587% 5.155% 0.000% 17.460% 18.226% 0.000%IA 37 36 1 187,920 53,303 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 657 630 27 926,227 707,598 218,629 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,369 1,265 104 9,186,672 2,986,275 6,200,397 0.657% 0.474% 2.885% 1.091% 1.775% 0.762%IN 1,403 1,359 44 4,866,831 2,547,095 2,319,736 0.071% 0.000% 2.273% 3.603% 0.000% 7.559%KY 242 93 149 4,602,489 375,460 4,227,029 2.066% 0.000% 3.356% 8.536% 0.000% 9.294%MA 635 524 111 8,407,608 1,680,442 6,727,166 0.315% 0.191% 0.901% 0.660% 0.922% 0.595%MD 858 790 68 4,904,050 905,943 3,998,107 0.816% 0.253% 7.353% 71.029% 2.798% 86.490%ME 741 688 53 719,849 284,275 435,574 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,037 1,977 60 6,884,269 1,707,979 5,176,290 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 646 596 50 693,590 318,486 375,104 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,361 2,228 133 6,786,602 1,733,551 5,053,051 0.296% 0.314% 0.000% 0.353% 1.384% 0.000%ND 28 22 6 47,665 40,636 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 773 762 11 1,462,281 685,801 776,480 0.129% 0.131% 0.000% 0.012% 0.026% 0.000%NH 1,214 1,196 18 614,066 395,955 218,111 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 1,397 1,360 37 7,747,090 2,711,144 5,035,946 0.859% 0.809% 2.703% 1.349% 2.175% 0.904%NM 282 267 15 1,419,356 1,213,960 205,396 0.355% 0.375% 0.000% 31.922% 37.322% 0.000%NV 313 293 20 968,909 279,110 689,799 0.319% 0.000% 5.000% 0.857% 0.000% 1.203%NY 347 265 82 1,394,537 376,495 1,018,042 2.594% 2.642% 2.439% 2.177% 0.985% 2.618%OH 10 5 5 2,712,928 92,894 2,620,034 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,084 934 150 2,937,104 572,354 2,364,750 0.092% 0.107% 0.000% 0.001% 0.005% 0.000%RI 145 136 9 913,884 173,906 739,978 0.690% 0.000% 11.111% 7.470% 0.000% 9.225%SC 783 723 60 3,445,274 811,841 2,633,433 3.448% 3.043% 8.333% 11.207% 8.494% 12.044%SD 292 271 21 655,146 295,975 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 10 5 5 595,572 109,942 485,630 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.061% 0.065% 0.000% 0.009% 0.025% 0.000%UT 4 4 0 24,010 24,010 0 25.000% 25.000% 0.000% 0.125% 0.125% 0.000%VA 1,502 1,334 168 3,371,566 606,017 2,765,549 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 248 223 25 353,810 127,114 226,696 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WI 762 752 10 2,780,940 1,562,033 1,218,907 0.394% 0.399% 0.000% 0.039% 0.069% 0.000%WV 343 197 146 1,370,967 206,754 1,164,213 2.624% 4.061% 0.685% 0.536% 1.440% 0.376%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 37,618 34,602 3,016 193,749,339 73,552,992 120,196,347 1.029% 0.922% 2.255% 9.268% 9.820% 8.929%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting

Table A21b. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A21c. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 6 5 1 3.243% 3.623% 2.128% 104,064 53,064 51,000 3.604% 7.222% 2.369%AR 1 1 0 0.220% 0.262% 0.000% 3,548 3,548 0 0.145% 0.390% 0.000%AZ 2 1 1 0.215% 0.113% 2.083% 168,000 28,000 140,000 2.775% 1.043% 4.154%CA 88 73 15 4.211% 4.065% 5.102% 2,317,857 793,249 1,524,608 6.721% 6.189% 7.035%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 2 2 0 1.835% 2.062% 0.000% 41,542 41,542 0 3.195% 3.335% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 1,409 1,409 0 0.021% 0.081% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 10 9 1 0.716% 0.662% 2.703% 103,891 58,391 45,500 1.341% 2.154% 0.904%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 0 1 0.319% 0.000% 5.000% 8,300 0 8,300 0.857% 0.000% 1.203%NY 7 6 1 2.017% 2.264% 1.220% 3,773 3,647 126 0.271% 0.969% 0.012%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 1 0 1 0.690% 0.000% 11.111% 68,263 0 68,263 7.470% 0.000% 9.225%SC 21 17 4 2.682% 2.351% 6.667% 322,423 45,812 276,611 9.358% 5.643% 10.504%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 3 3 0 0.061% 0.065% 0.000% 2,347 2,347 0 0.009% 0.025% 0.000%UT 1 1 0 25.000% 25.000% 0.000% 30 30 0 0.125% 0.125% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.583% 0.508% 0.685% 6,044 1,670 4,374 0.441% 0.808% 0.376%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 146 120 26 0.388% 0.347% 0.862% 3,151,491 1,032,709 2,118,782 1.627% 1.404% 1.763%

Percent of Population Served 

with At Least One Detection 

> 0.2 μg/L State

Number of Systems 

with At Least One Detection 

> 0.2 μg/L

Percent of Systems 

with At Least One Detection 

> 0.2 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.2 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A21d. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 8 6 2 4.324% 4.348% 4.255% 143,180 63,009 80,171 4.959% 8.576% 3.724%AR 2 2 0 0.441% 0.524% 0.000% 31,892 31,892 0 1.300% 3.503% 0.000%AZ 5 4 1 0.537% 0.453% 2.083% 168,736 28,736 140,000 2.787% 1.071% 4.154%CA 129 112 17 6.172% 6.236% 5.782% 2,737,737 1,066,181 1,671,556 7.938% 8.318% 7.713%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 2 2 0 1.835% 2.062% 0.000% 41,542 41,542 0 3.195% 3.335% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 0 1 0.073% 0.000% 0.962% 1,502 0 1,502 0.016% 0.000% 0.024%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 13,807 0 13,807 0.300% 0.000% 0.327%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 3 1 2 0.350% 0.127% 2.941% 3,445,000 25,000 3,420,000 70.248% 2.760% 85.540%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 1,409 1,409 0 0.021% 0.081% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 11 10 1 0.787% 0.735% 2.703% 104,311 58,811 45,500 1.346% 2.169% 0.904%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 0 1 0.319% 0.000% 5.000% 8,300 0 8,300 0.857% 0.000% 1.203%NY 7 6 1 2.017% 2.264% 1.220% 3,773 3,647 126 0.271% 0.969% 0.012%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 1 1 0 0.092% 0.107% 0.000% 31 31 0 0.001% 0.005% 0.000%RI 1 0 1 0.690% 0.000% 11.111% 68,263 0 68,263 7.470% 0.000% 9.225%SC 21 17 4 2.682% 2.351% 6.667% 322,423 45,812 276,611 9.358% 5.643% 10.504%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 3 3 0 0.061% 0.065% 0.000% 2,347 2,347 0 0.009% 0.025% 0.000%UT 1 1 0 25.000% 25.000% 0.000% 30 30 0 0.125% 0.125% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.131% 0.133% 0.000% 200 200 0 0.007% 0.013% 0.000%WV 2 1 1 0.583% 0.508% 0.685% 6,044 1,670 4,374 0.441% 0.808% 0.376%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 201 168 33 0.534% 0.486% 1.094% 7,100,527 1,370,317 5,730,210 3.665% 1.863% 4.767%

Percent of Population Served 

with At Least One Detection 

	
 State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A22. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 600 μg/L 46,166 0 0.000% 86,389,766 0 0.000%

	
 46,166 0 0.000% 86,389,766 0 0.000%

> 600 μg/L 4,256 0 0.000% 140,540,050 0 0.000%

	
 4,256 0 0.000% 140,540,050 0 0.000%

> 600 μg/L 50,422 0 0.000% 226,929,816 0 0.000%

	
 50,422 0 0.000% 226,929,816 0 0.000%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A22a. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,169 2,037 1,132 0.032% 0.049% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5AL 820 596 224 0.000% 0.000% 0.000%AR 2,383 1,915 468 0.000% 0.000% 0.000%AZ 11,712 9,540 2,172 0.026% 0.000% 0.138% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5CA 85,811 45,401 40,410 0.010% 0.015% 0.005% 0.03 0.6 0.03 0.8 0.8 3.015 6 1.1 6 6 1.1 6CO 2,864 2,125 739 0.209% 0.235% 0.135% 0.04 0.04 0.05 0.045 0.04 0.05 0.06 0.06 0.05 0.06 0.06 0.05CT 6,936 6,045 891 0.130% 0.149% 0.000% 0.6 0.6 1.5 1.5 6.9 6.9 6.9 6.9DE 1,047 1,017 30 0.000% 0.000% 0.000%FL 4,151 4,083 68 0.554% 0.563% 0.000% 0.07 0.07 0.5 0.5 2 2 2.4 2.4GA 7,174 6,347 827 0.000% 0.000% 0.000%HI 1,790 1,687 103 0.000% 0.000% 0.000%IA 1,757 1,632 125 0.000% 0.000% 0.000%ID 3,751 3,290 461 0.000% 0.000% 0.000%IL 6,996 6,436 560 0.029% 0.031% 0.000% 0.68 0.68 0.94 0.94 1.2 1.2 1.2 1.2IN 4,621 4,311 310 0.000% 0.000% 0.000%KY 3,311 1,127 2,184 0.453% 0.000% 0.687% 0.004 0.004 0.5 0.5 1.2 1.2 1.4 1.4MA 16,249 12,259 3,990 0.123% 0.163% 0.000% 0.4 0.4 0.76 0.76 35 35 45 45MD 6,771 5,509 1,262 0.118% 0.127% 0.079% 0.1 0.4 0.1 1.15 1.2 0.1 16 16 0.1 16 16 0.1ME 3,697 3,382 315 0.081% 0.089% 0.000% 0.5 0.5 0.5 0.5 1.9 1.9 1.9 1.9MI 10,753 9,743 1,010 0.186% 0.205% 0.000% 0.5 0.5 0.8 0.8 0.9 0.9 1 1MN 8,581 7,332 1,249 0.035% 0.041% 0.000% 0.2 0.2 0.3 0.3 0.7 0.7 0.7 0.7MO 7,544 6,695 849 0.000% 0.000% 0.000%MT 4,491 3,952 539 0.000% 0.000% 0.000%NC 19,067 17,487 1,580 0.115% 0.126% 0.000% 0.5 0.5 0.8 0.8 1.7 1.7 4.9 4.9ND 555 418 137 0.541% 0.718% 0.000% 0.6 0.6 1.02 1.02 6.94 6.94 6.94 6.94NE 6,835 6,257 578 0.015% 0.000% 0.173% 1 1 1 1 1 1 1 1NH 9,594 9,112 482 0.250% 0.198% 1.245% 0.5 0.5 0.5 1.05 1.1 0.6 1.4 1.4 2.1 2.1 1.4 2.1NJ 20,354 18,568 1,786 0.206% 0.205% 0.224% 0.09 0.09 0.2 1.1 1.325 0.3 4.42 4.69 0.4 9.04 9.04 0.4NM 6,572 6,096 476 0.000% 0.000% 0.000%NV 3,202 2,575 627 0.344% 0.427% 0.000% 1.43 1.43 2.99 2.99 7.93 7.93 110 110NY 7,082 5,424 1,658 0.085% 0.074% 0.121% 0.5 0.5 0.5 0.5 0.5 0.5 0.7 0.7 0.5 0.7 0.7 0.5OH 8,853 7,691 1,162 0.000% 0.000% 0.000%OK 5,638 4,202 1,436 0.000% 0.000% 0.000%OR 2,326 1,684 642 0.043% 0.059% 0.000% 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1RI 1,959 1,591 368 0.000% 0.000% 0.000%SC 4,326 3,789 537 0.023% 0.000% 0.186% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1SD 889 855 34 0.000% 0.000% 0.000%TN 2,947 1,166 1,781 0.000% 0.000% 0.000%TX 34,144 27,040 7,104 0.006% 0.007% 0.000% 0.5 0.5 0.9 0.9 1.3 1.3 1.3 1.3UT 8,989 7,563 1,426 0.000% 0.000% 0.000%VA 4,888 4,021 867 0.020% 0.025% 0.000% 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7VT 4,270 3,887 383 0.375% 0.412% 0.000% 1 1 2 2 2.6 2.6 3 3WI 11,293 11,168 125 0.071% 0.072% 0.000% 0.01 0.01 0.44 0.44 90 90 90 90WV 1,126 438 688 1.155% 2.511% 0.291% 0.21 0.21 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5WY 1,658 1,155 503 0.000% 0.000% 0.000%Total 372,946 288,648 84,298 0.073% 0.081% 0.045% 0.004 0.01 0.004 0.8 0.9 0.5 2.74 3 1.3 110 110 6

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A22b. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.161% 0.211% 0.000% 0.825% 2.150% 0.000%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.094% 0.000% 2.083% 4.865% 0.000% 8.901%CA 3,650 3,133 517 35,827,368 13,514,907 22,312,461 0.164% 0.128% 0.387% 0.901% 0.897% 0.903%CO 826 605 221 4,997,841 530,207 4,467,634 0.605% 0.661% 0.452% 0.016% 0.112% 0.005%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.249% 0.257% 0.000% 0.065% 0.454% 0.000%DE 318 315 3 698,987 417,587 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,510 1,484 26 17,495,564 15,249,522 2,246,042 0.331% 0.337% 0.000% 1.033% 1.185% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.140% 0.151% 0.000% 0.012% 0.036% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 4.149% 0.000% 6.711% 10.100% 0.000% 10.996%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.557% 0.667% 0.000% 0.101% 0.494% 0.000%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.474% 0.406% 1.471% 34.044% 0.014% 42.770%ME 810 757 53 728,347 292,773 435,574 0.370% 0.396% 0.000% 0.043% 0.106% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.034% 0.034% 0.000% 0.004% 0.014% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.190% 0.193% 0.000% 0.075% 0.106% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 848 788 60 757,949 365,280 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.465% 0.494% 0.000% 0.029% 0.117% 0.000%ND 209 182 27 562,332 257,107 305,225 0.957% 1.099% 0.000% 0.341% 0.745% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.130% 0.000% 9.091% 35.027% 0.000% 65.960%NH 1,258 1,217 41 948,788 398,989 549,799 0.397% 0.329% 2.439% 3.786% 0.480% 6.184%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 1.001% 0.955% 2.703% 1.420% 3.935% 0.066%NM 727 688 39 1,698,980 1,432,432 266,548 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 338 317 21 973,592 283,701 689,891 0.592% 0.631% 0.000% 0.209% 0.717% 0.000%NY 1,520 1,284 236 4,893,045 1,042,443 3,850,602 0.395% 0.312% 0.847% 0.082% 0.355% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OK 730 518 212 3,123,687 664,833 2,458,854 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.091% 0.106% 0.000% 0.020% 0.104% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 817 755 62 3,356,049 732,097 2,623,952 0.122% 0.000% 1.613% 0.479% 0.000% 0.612%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.040% 0.043% 0.000% 0.039% 0.106% 0.000%UT 500 454 46 2,553,197 1,698,877 854,320 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 1,590 1,420 170 5,269,962 628,527 4,641,435 0.063% 0.070% 0.000% 0.002% 0.019% 0.000%VT 603 560 43 491,035 227,067 263,968 0.332% 0.357% 0.000% 0.044% 0.095% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.336% 0.340% 0.000% 0.285% 0.491% 0.000%WV 402 242 160 1,415,371 237,021 1,178,350 3.234% 4.545% 1.250% 2.060% 0.979% 2.277%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,422 46,166 4,256 226,929,816 86,389,766 140,540,050 0.230% 0.201% 0.540% 1.646% 0.539% 2.326%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A22c. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 600 μg/L

State

Number of Systems 

with At Least One Detection 

> 600 μg/L

Percent of Systems 

with At Least One Detection 

> 600 μg/L

Population Served by Systems 

with At Least One Detection 

> 600 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A22d. 1,2-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A23. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 75 μg/L 45,785 3 0.007% 85,479,601 99,019 0.116%

	
 45,785 6 0.013% 85,479,601 103,510 0.121%

> 75 μg/L 4,184 0 0.000% 138,997,024 0 0.000%

	
 4,184 0 0.000% 138,997,024 0 0.000%

> 75 μg/L 49,969 3 0.006% 224,476,625 99,019 0.044%

	
 49,969 6 0.012% 224,476,625 103,510 0.046%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A23a. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,184 2,046 1,138 0.345% 0.293% 0.439% 0.31 0.32 0.31 0.6 2.08 0.6 4.3 5 1.5 5 5 1.5AL 822 597 225 0.365% 0.335% 0.444% 0.8 0.8 1.5 1.23 1.015 1.5 1.5 1.23 1.5 1.5 1.23 1.5ARAZ 11,687 9,520 2,167 0.034% 0.011% 0.138% 0.5 0.9 0.5 0.5 0.9 0.5 0.9 0.9 0.5 0.9 0.9 0.5CA 85,845 45,431 40,414 0.047% 0.059% 0.032% 0.01 0.51 0.01 0.89 1 0.53 3.6 10 1.4 91 91 2.2CO 2,867 2,124 743 0.837% 0.612% 1.480% 0.04 0.04 0.05 0.06 0.05 0.74 1.5 0.07 11.8 13.6 0.3 13.6CT 6,936 6,045 891 0.663% 0.761% 0.000% 0.6 0.6 0.955 0.955 1.7 1.7 700 700DE 1,050 1,020 30 0.667% 0.686% 0.000% 0.56 0.56 0.85 0.85 4.11 4.11 4.11 4.11FL 4,156 4,089 67 0.577% 0.587% 0.000% 0.0052 0.0052 1.295 1.295 5.3 5.3 41 41GA 7,174 6,347 827 0.251% 0.252% 0.242% 0.54 0.54 0.83 1.55 1.55 1.315 4.3 4.3 1.8 4.5 4.5 1.8HI 1,790 1,687 103 0.000% 0.000% 0.000%IA 1,803 1,665 138 1.664% 1.261% 6.522% 0.2 0.2 0.5 0.7 0.7 0.7 1.4 1.4 1.3 5.1 5.1 1.3ID 3,750 3,289 461 0.053% 0.061% 0.000% 0.1 0.1 0.4 0.4 0.7 0.7 0.7 0.7IL 7,002 6,442 560 0.314% 0.264% 0.893% 0.21 0.21 0.59 0.9 0.9 0.9 1.45 1.7 1.11 7 7 1.11IN 4,624 4,314 310 1.125% 1.205% 0.000% 0.5 0.5 1 1 2.4 2.4 7.9 7.9KY 3,314 1,128 2,186 0.634% 0.266% 0.823% 0.002 0.5 0.002 0.5 0.5 0.5 1 0.7 1.2 6 0.7 6MA 16,249 12,259 3,990 0.215% 0.237% 0.150% 0.3 0.3 0.4 1.1 1.3 0.495 8.9 9 1.4 50 50 1.4MD 6,771 5,509 1,262 0.753% 0.908% 0.079% 0.2 0.2 0.2 0.9 0.95 0.2 3.8 4.3 0.2 8.4 8.4 0.2ME 3,697 3,382 315 0.270% 0.266% 0.317% 0.42 0.42 1.7 0.65 0.6 1.7 2.15 2.6 1.7 2.6 2.6 1.7MI 10,753 9,743 1,010 0.549% 0.585% 0.198% 0.4 0.4 0.5 0.6 0.7 0.55 1.8 1.8 0.6 9.3 9.3 0.6MN 8,597 7,339 1,258 0.826% 0.627% 1.987% 0.2 0.2 0.2 0.4 0.4 0.4 1.5 1.9 0.8 4.2 4.2 2.5MO 7,544 6,695 849 0.278% 0.239% 0.589% 0.5 0.5 0.5 1.1 1.25 0.7 3 3.5 2.3 47.8 47.8 2.3MT 4,491 3,952 539 0.022% 0.025% 0.000% 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58NC 19,068 17,488 1,580 0.210% 0.223% 0.063% 0.5 0.5 0.6 0.9 0.9 0.6 1.75 1.9 0.6 91.5 91.5 0.6ND 551 416 135 1.089% 0.000% 4.444% 0.74 0.74 1.11 1.11 1.86 1.86 1.86 1.86NE 6,835 6,257 578 0.132% 0.128% 0.173% 0.5 0.5 1.1 0.66 0.625 1.1 4.6 4.6 1.1 4.6 4.6 1.1NH 9,600 9,122 478 0.469% 0.493% 0.000% 0.52 0.52 1.1 1.1 2.7 2.7 5 5NJ 20,349 18,563 1,786 0.580% 0.620% 0.168% 0.07 0.07 0.1 0.515 0.52 0.1 1.92 1.92 1 25.21 25.21 1NM 6,578 6,102 476 0.106% 0.115% 0.000% 0.3 0.3 1 1 1.4 1.4 1.4 1.4NV 3,204 2,575 629 0.343% 0.427% 0.000% 0.1 0.1 1.07 1.07 1.52 1.52 1.7 1.7NY 7,083 5,425 1,658 0.212% 0.240% 0.121% 0.5 0.5 0.5 1.2 1.5 0.5 2.1 2.1 0.5 3.4 3.4 0.5OH 8,848 7,686 1,162 1.288% 1.483% 0.000% 0.5 0.5 1.1 1.1 4.18 4.18 14.2 14.2OK 5,638 4,202 1,436 0.603% 0.714% 0.279% 0.4 0.5 0.4 1.2 1.22 0.95 4.3 5.15 1.4 16.3 16.3 1.4OR 2,324 1,682 642 0.000% 0.000% 0.000%RI 1,959 1,591 368 0.051% 0.063% 0.000% 1.7 1.7 1.7 1.7 1.7 1.7 1.7 1.7SC 4,330 3,793 537 0.069% 0.000% 0.559% 0.3 0.3 0.59 0.59 0.97 0.97 0.97 0.97SD 889 855 34 0.000% 0.000% 0.000%TN 2,951 1,165 1,786 0.441% 0.000% 0.728% 0.52 0.52 0.71 0.71 1.1 1.1 2 2TX 34,146 27,040 7,106 0.343% 0.318% 0.436% 0.5 0.5 0.5 0.8 0.9 0.7 1.6 1.5 1.6 3.5 3.5 2.1UT 8,993 7,562 1,431 0.111% 0.132% 0.000% 0.1 0.1 0.4 0.4 4.7 4.7 4.7 4.7VA 4,883 4,015 868 0.369% 0.399% 0.230% 0.6 0.6 0.6 0.75 0.8 0.65 1.7 1.7 0.7 2.7 2.7 0.7VT 4,270 3,886 384 0.562% 0.618% 0.000% 0.6 0.6 1.5 1.5 2 2 2.3 2.3WI 11,295 11,170 125 1.965% 1.952% 3.200% 0.02 0.02 0.1 0.42 0.43 0.15 2.5 2.5 0.24 16 16 0.24WV 1,140 448 692 1.404% 2.902% 0.434% 0.27 0.27 0.5 0.5 0.5 0.5 1.21 1.21 0.8 1.21 1.21 0.8WY 1,658 1,155 503 0.121% 0.000% 0.398% 0.7 0.7 0.75 0.75 0.8 0.8 0.8 0.8Total 370,698 286,821 83,877 0.371% 0.417% 0.217% 0.002 0.0052 0.002 0.8 0.8 0.6 2.4 2.5 1.4 700 700 13.6

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A23b. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 1.290% 0.844% 2.740% 1.462% 2.259% 0.965%AL 263 202 61 4,218,278 1,123,190 3,095,088 1.141% 0.990% 1.639% 0.550% 0.164% 0.690%ARAZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.189% 0.099% 2.083% 4.866% 0.004% 8.901%CA 3,651 3,134 517 35,827,608 13,515,147 22,312,461 0.685% 0.670% 0.774% 2.536% 3.853% 1.739%CO 826 605 221 4,997,841 530,207 4,467,634 1.695% 1.653% 1.810% 0.080% 0.488% 0.032%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 1.326% 1.370% 0.000% 0.047% 0.330% 0.000%DE 319 316 3 699,187 417,787 281,400 1.881% 1.899% 0.000% 0.210% 0.352% 0.000%FL 1,510 1,484 26 17,495,564 15,249,522 2,246,042 1.325% 1.348% 0.000% 0.831% 0.954% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.329% 0.293% 0.862% 0.078% 0.115% 0.068%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 1.610% 1.271% 12.121% 6.196% 0.989% 12.934%ID 935 878 57 1,093,666 837,604 256,062 0.214% 0.228% 0.000% 0.034% 0.045% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.910% 0.906% 0.962% 2.508% 4.381% 1.597%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 1.832% 1.888% 0.000% 3.692% 7.023% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 5.809% 3.261% 7.383% 10.078% 0.571% 10.922%MA 718 600 118 8,557,325 1,749,901 6,807,424 2.507% 2.500% 2.542% 1.185% 2.923% 0.738%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 2.467% 2.535% 1.471% 34.301% 1.275% 42.770%ME 810 757 53 728,347 292,773 435,574 0.988% 0.925% 1.887% 1.026% 0.478% 1.395%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.841% 0.790% 3.279% 1.501% 1.146% 1.636%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 2.528% 2.062% 26.667% 7.596% 5.521% 12.597%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 1.059% 0.896% 3.896% 1.957% 0.445% 3.901%MT 848 788 60 757,949 365,280 392,669 0.118% 0.127% 0.000% 0.012% 0.026% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 1.352% 1.391% 0.719% 0.734% 1.932% 0.339%ND 209 182 27 562,332 257,107 305,225 0.478% 0.000% 3.704% 0.676% 0.000% 1.245%NE 771 760 11 1,462,181 685,701 776,480 0.908% 0.789% 9.091% 35.082% 0.116% 65.960%NH 1,258 1,217 41 948,788 398,989 549,799 1.431% 1.479% 0.000% 0.313% 0.744% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 3.720% 3.674% 5.405% 2.737% 6.111% 0.919%NM 727 688 39 1,698,980 1,432,432 266,548 0.963% 1.017% 0.000% 0.207% 0.245% 0.000%NV 338 317 21 973,592 283,701 689,891 1.479% 1.577% 0.000% 0.164% 0.564% 0.000%NY 1,520 1,284 236 4,893,045 1,042,443 3,850,602 0.724% 0.701% 0.847% 0.107% 0.471% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 2.675% 2.859% 0.000% 0.199% 0.651% 0.000%OK 730 518 212 3,123,687 664,833 2,458,854 1.918% 2.317% 0.943% 2.165% 2.015% 2.205%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 145 136 9 913,884 173,906 739,978 0.690% 0.735% 0.000% 0.022% 0.115% 0.000%SC 818 756 62 3,356,179 732,227 2,623,952 0.244% 0.000% 3.226% 11.987% 0.000% 15.332%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 1.709% 0.000% 3.175% 2.033% 0.000% 2.737%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 1.737% 1.410% 6.140% 3.204% 1.366% 4.284%UT 500 454 46 2,553,197 1,698,877 854,320 0.600% 0.661% 0.000% 0.029% 0.044% 0.000%VA 1,587 1,417 170 5,268,900 627,465 4,641,435 0.630% 0.565% 1.176% 0.421% 0.477% 0.413%VT 603 560 43 491,035 227,067 263,968 1.161% 1.250% 0.000% 0.116% 0.252% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 6.278% 6.179% 15.000% 10.150% 16.047% 1.966%WV 403 243 160 1,416,020 237,670 1,178,350 3.722% 4.938% 1.875% 5.102% 0.944% 5.940%WY 304 256 48 446,177 129,229 316,948 0.329% 0.000% 2.083% 0.013% 0.000% 0.019%Total 49,969 45,785 4,184 224,476,625 85,479,601 138,997,024 1.497% 1.424% 2.294% 3.325% 2.374% 3.910%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A23c. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ARAZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.027% 0.032% 0.000% 98,730 98,730 0 0.276% 0.731% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.083% 0.086% 0.000% 60 60 0 0.002% 0.015% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 229 229 0 0.003% 0.013% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 3 3 0 0.006% 0.007% 0.000% 99,019 99,019 0 0.044% 0.116% 0.000%

Percent of Population Served 

with At Least One Detection 

> 75 μg/L

State

Number of Systems 

with At Least One Detection 

> 75 μg/L

Percent of Systems 

with At Least One Detection 

> 75 μg/L

Population Served by Systems 

with At Least One Detection 

> 75 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A23d. 1,4-Dichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ARAZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.027% 0.032% 0.000% 98,730 98,730 0 0.276% 0.731% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.083% 0.086% 0.000% 60 60 0 0.002% 0.015% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.066% 0.067% 0.000% 26 26 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 1 1 0 0.139% 0.167% 0.000% 65 65 0 0.001% 0.004% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.071% 0.075% 0.000% 4,400 4,400 0 0.146% 0.260% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 229 229 0 0.003% 0.013% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 6 6 0 0.012% 0.013% 0.000% 103,510 103,510 0 0.046% 0.121% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A24. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 46,185 33 0.071% 86,392,793 247,240 0.286%

	
 46,185 58 0.126% 86,392,793 337,994 0.391%

	
 46,185 139 0.301% 86,392,793 858,498 0.994%

> 0.5 μg/L 46,185 214 0.463% 86,392,793 1,399,602 1.620%

> 5 μg/L 4,257 3 0.070% 140,541,198 190,972 0.136%

	
 4,257 8 0.188% 140,541,198 4,412,609 3.140%

	
 4,257 25 0.587% 140,541,198 5,428,439 3.863%

> 0.5 μg/L 4,257 41 0.963% 140,541,198 7,551,832 5.373%

> 5 μg/L 50,442 36 0.071% 226,933,991 438,212 0.193%

	
 50,442 66 0.131% 226,933,991 4,750,603 2.093%

	
 50,442 164 0.325% 226,933,991 6,286,937 2.770%

> 0.5 μg/L 50,442 255 0.506% 226,933,991 8,951,434 3.945%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A24a. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,110 1,973 1,137 0.450% 0.456% 0.440% 0.21 0.21 0.5 0.675 0.76 0.59 1.2 1.3 1.08 1.3 1.3 1.08AL 827 603 224 1.088% 1.493% 0.000% 0.5 0.5 1.1 1.1 2.07 2.07 2.07 2.07AR 2,394 1,926 468 0.376% 0.467% 0.000% 0.1 0.1 0.29 0.29 5.58 5.58 5.58 5.58AZ 11,693 9,525 2,168 0.111% 0.105% 0.138% 0.5 0.59 0.5 0.7 0.9 0.5 1.5 1.6 0.5 1.7 1.7 0.5CA 88,321 46,908 41,413 1.127% 1.190% 1.055% 0.13 0.13 0.5 1.2 1.9 0.75 3.1 3.7 1.8 33 11 33CO 2,878 2,139 739 0.243% 0.327% 0.000% 0.5 0.5 3.6 3.6 26 26 26 26CT 6,938 6,047 891 0.115% 0.116% 0.112% 0.6 0.6 1.2 1.05 0.9 1.2 15 15 1.2 15 15 1.2DE 1,069 1,039 30 0.374% 0.289% 3.333% 0.63 0.63 5.19 0.745 0.69 5.19 5.19 0.8 5.19 5.19 0.8 5.19FL 4,147 4,079 68 0.482% 0.490% 0.000% 0.07 0.07 0.13 0.13 0.3 0.3 4.18 4.18GA 7,176 6,349 827 0.543% 0.378% 1.814% 0.5 0.5 1.1 1.5 0.745 2.2 2.5 2.1 2.6 2.7 2.6 2.7HI 1,791 1,688 103 0.000% 0.000% 0.000%IA 1,823 1,698 125 0.549% 0.589% 0.000% 0.1 0.1 0.8 0.8 1.95 1.95 2.2 2.2ID 3,765 3,304 461 0.027% 0.030% 0.000% 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6IL 6,998 6,438 560 0.029% 0.031% 0.000% 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8IN 4,623 4,313 310 0.043% 0.023% 0.323% 0.8 1.6 0.8 1.2 1.6 0.8 1.6 1.6 0.8 1.6 1.6 0.8KY 3,317 1,131 2,186 0.422% 0.088% 0.595% 0.005 0.1 0.005 0.195 0.1 0.2 0.5 0.1 0.5 1 0.1 1MA 16,249 12,259 3,990 0.172% 0.082% 0.451% 0.41 0.5 0.41 1.15 1 1.15 3.4 2.05 4 47 2.1 47MD 6,773 5,511 1,262 0.340% 0.327% 0.396% 0.1 0.6 0.1 1.5 2.6 1 54.5 65.3 1.2 135.8 135.8 1.2ME 3,697 3,382 315 0.189% 0.207% 0.000% 0.5 0.5 1.1 1.1 7.3 7.3 7.3 7.3MI 10,753 9,743 1,010 0.400% 0.441% 0.000% 0.5 0.5 1 1 8.9 8.9 13.3 13.3MN 8,584 7,335 1,249 1.153% 1.350% 0.000% 0.2 0.2 0.7 0.7 4.1 4.1 11 11MO 7,544 6,695 849 0.106% 0.119% 0.000% 0.5 0.5 0.85 0.85 1.8 1.8 1.8 1.8MT 4,491 3,952 539 0.089% 0.101% 0.000% 0.69 0.69 0.905 0.905 4.3 4.3 4.3 4.3NC 19,067 17,487 1,580 0.393% 0.423% 0.063% 0.5 0.5 0.82 1.42 1.56 0.82 5.3 5.3 0.82 9.7 9.7 0.82ND 552 417 135 0.000% 0.000% 0.000%NE 6,844 6,265 579 0.921% 0.990% 0.173% 0.11 0.11 0.25 0.6 0.645 0.25 2.36 2.36 0.25 14 14 0.25NH 9,583 9,105 478 0.230% 0.242% 0.000% 0.6 0.6 0.945 0.945 14 14 62.74 62.74NJ 20,359 18,571 1,788 0.894% 0.781% 2.069% 0.08 0.08 0.2 0.56 0.5 0.6 1.4 1.51 1.2 10 10 1.8NM 6,577 6,102 475 0.091% 0.082% 0.211% 0.1 0.1 0.8 0.645 0.55 0.8 0.99 0.99 0.8 0.99 0.99 0.8NV 3,210 2,579 631 0.031% 0.039% 0.000% 0.81 0.81 0.81 0.81 0.81 0.81 0.81 0.81NY 7,081 5,412 1,669 0.254% 0.296% 0.120% 0.5 0.5 0.5 0.66 0.7 0.5 11.7 11.7 0.5 46 46 0.5OH 8,848 7,686 1,162 0.068% 0.052% 0.172% 0.5 0.5 1.1 1 0.76 2.275 3.45 2.6 3.45 3.45 2.6 3.45OK 5,636 4,201 1,435 2.129% 2.833% 0.070% 0.3 0.3 0.7 0.9 0.9 0.7 2.75 2.8 0.7 5 5 0.7OR 2,324 1,682 642 0.000% 0.000% 0.000%RI 1,959 1,591 368 0.000% 0.000% 0.000%SC 4,340 3,801 539 0.323% 0.263% 0.742% 0.58 0.58 0.58 1.69 1.83 1.125 2.22 2.285 1.69 2.35 2.35 1.69SD 889 855 34 0.112% 0.117% 0.000% 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3TN 2,945 1,165 1,780 0.136% 0.258% 0.056% 0.52 0.52 0.55 0.585 0.62 0.55 0.75 0.75 0.55 0.75 0.75 0.55TX 34,145 27,041 7,104 0.152% 0.148% 0.169% 0.5 0.5 0.5 1.05 1.3 0.85 4.1 6.65 1 8.3 8.3 1.1UT 8,994 7,563 1,431 0.000% 0.000% 0.000%VA 4,931 4,058 873 0.507% 0.616% 0.000% 0.5 0.5 0.8 0.8 1.4 1.4 6.4 6.4VT 4,351 3,957 394 0.161% 0.177% 0.000% 0.5 0.5 0.6 0.6 1.6 1.6 1.6 1.6WI 11,291 11,166 125 1.081% 1.093% 0.000% 0.01 0.01 0.285 0.285 0.76 0.76 15 15WV 1,140 444 696 1.228% 2.477% 0.431% 0.11 0.11 0.5 0.5 0.5 0.5 0.5 0.5 1 1 0.5 1WY 1,609 1,123 486 0.000% 0.000% 0.000%Total 375,636 290,308 85,328 0.557% 0.526% 0.661% 0.005 0.01 0.005 0.9 1 0.745 3.1 3.6 2 135.8 135.8 47

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A24b. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 1.290% 0.844% 2.740% 7.760% 9.240% 6.839%AL 263 202 61 4,218,278 1,123,190 3,095,088 2.281% 2.970% 0.000% 3.013% 11.315% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.881% 1.047% 0.000% 0.200% 0.540% 0.000%AZ 1,058 1,010 48 6,162,837 2,792,246 3,370,591 0.473% 0.396% 2.083% 5.004% 0.300% 8.901%CA 3,653 3,136 517 35,828,228 13,515,767 22,312,461 0.876% 0.638% 2.321% 19.192% 2.977% 29.013%CO 826 605 221 4,997,841 530,207 4,467,634 0.121% 0.165% 0.000% 0.001% 0.008% 0.000%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.497% 0.428% 2.564% 1.328% 0.108% 1.531%DE 318 315 3 698,987 417,587 281,400 1.258% 0.952% 33.333% 5.308% 0.233% 12.839%FL 1,509 1,483 26 17,495,514 15,249,472 2,246,042 0.530% 0.539% 0.000% 3.892% 4.465% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.329% 0.293% 0.862% 0.120% 0.266% 0.081%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.568% 0.587% 0.000% 0.197% 0.349% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.107% 0.114% 0.000% 0.045% 0.059% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.070% 0.075% 0.000% 0.011% 0.035% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.136% 0.070% 2.273% 7.706% 4.410% 11.360%KY 241 92 149 4,602,392 375,363 4,227,029 3.320% 1.087% 4.698% 9.250% 0.027% 10.069%MA 718 600 118 8,557,325 1,749,901 6,807,424 2.089% 1.167% 6.780% 3.036% 2.864% 3.080%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 1.233% 1.014% 4.412% 36.273% 0.591% 45.424%ME 810 757 53 728,347 292,773 435,574 0.494% 0.528% 0.000% 0.194% 0.483% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.202% 0.206% 0.000% 0.146% 0.528% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 1.011% 1.031% 0.000% 1.625% 2.300% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.212% 0.224% 0.000% 0.091% 0.161% 0.000%MT 848 788 60 757,949 365,280 392,669 0.354% 0.381% 0.000% 0.051% 0.105% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.972% 0.987% 0.719% 0.243% 0.668% 0.103%ND 210 183 27 562,397 257,172 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 771 760 11 1,462,181 685,701 776,480 3.502% 3.421% 9.091% 41.259% 13.289% 65.960%NH 1,258 1,217 41 948,788 398,989 549,799 0.715% 0.740% 0.000% 2.084% 4.955% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 3.004% 2.719% 13.514% 13.719% 8.135% 16.727%NM 727 688 39 1,698,980 1,432,432 266,548 0.550% 0.436% 2.564% 32.644% 33.643% 27.275%NV 338 317 21 973,592 283,701 689,891 0.296% 0.315% 0.000% 0.044% 0.151% 0.000%NY 1,525 1,289 236 4,895,654 1,045,052 3,850,602 0.656% 0.621% 0.847% 0.226% 1.030% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.309% 0.220% 1.600% 0.194% 0.024% 0.269%OK 730 518 212 3,123,687 664,833 2,458,854 2.877% 3.861% 0.472% 2.724% 11.827% 0.263%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.488% 0.264% 3.226% 0.275% 0.029% 0.344%SD 245 233 12 266,416 194,218 72,198 0.408% 0.429% 0.000% 0.289% 0.396% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.570% 0.617% 0.529% 0.194% 0.359% 0.136%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.222% 0.217% 0.292% 0.197% 0.285% 0.145%UT 500 454 46 2,553,197 1,698,877 854,320 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 0.563% 0.630% 0.000% 0.052% 0.438% 0.000%VT 603 560 43 491,035 227,067 263,968 0.829% 0.893% 0.000% 1.016% 2.198% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 1.626% 1.644% 0.000% 10.736% 18.471% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.193% 1.018% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,442 46,185 4,257 226,933,991 86,392,793 140,541,198 0.745% 0.686% 1.386% 6.178% 3.361% 7.909%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A24c. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 1 1 0 0.220% 0.262% 0.000% 240 240 0 0.010% 0.026% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 5 4 1 0.137% 0.128% 0.193% 189,990 84,658 105,332 0.530% 0.626% 0.472%CO 1 1 0 0.121% 0.165% 0.000% 40 40 0 0.001% 0.008% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 250 250 0 0.009% 0.064% 0.000%DE 1 0 1 0.314% 0.000% 33.333% 36,130 0 36,130 5.169% 0.000% 12.839%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 1 0 1 0.139% 0.000% 0.847% 49,510 0 49,510 0.579% 0.000% 0.727%MD 2 2 0 0.190% 0.203% 0.000% 75 75 0 0.001% 0.007% 0.000%ME 1 1 0 0.123% 0.132% 0.000% 45 45 0 0.006% 0.015% 0.000%MI 2 2 0 0.067% 0.069% 0.000% 396 396 0 0.006% 0.020% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 52,612 52,612 0 1.235% 1.747% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 3 0 0.127% 0.135% 0.000% 4,152 4,152 0 0.059% 0.240% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 0.259% 0.263% 0.000% 387 387 0 0.026% 0.056% 0.000%NH 2 2 0 0.159% 0.164% 0.000% 82 82 0 0.009% 0.021% 0.000%NJ 3 3 0 0.215% 0.220% 0.000% 83,427 83,427 0 1.077% 3.076% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 2 2 0 0.131% 0.155% 0.000% 1,735 1,735 0 0.035% 0.166% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 4 4 0 0.081% 0.087% 0.000% 18,221 18,221 0 0.073% 0.196% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.070% 0.000% 80 80 0 0.002% 0.013% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.112% 0.113% 0.000% 840 840 0 0.021% 0.036% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 36 33 3 0.071% 0.071% 0.070% 438,212 247,240 190,972 0.193% 0.286% 0.136%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A24d. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 1 1 0 0.220% 0.262% 0.000% 240 240 0 0.010% 0.026% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 10 7 3 0.274% 0.223% 0.580% 4,409,379 138,080 4,271,299 12.307% 1.022% 19.143%CO 1 1 0 0.121% 0.165% 0.000% 40 40 0 0.001% 0.008% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 250 250 0 0.009% 0.064% 0.000%DE 1 0 1 0.314% 0.000% 33.333% 36,130 0 36,130 5.169% 0.000% 12.839%FL 1 1 0 0.066% 0.067% 0.000% 1,400 1,400 0 0.008% 0.009% 0.000%GA 2 1 1 0.110% 0.059% 0.862% 5,187 437 4,750 0.069% 0.027% 0.081%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 2 0 2 0.279% 0.000% 1.695% 100,344 0 100,344 1.173% 0.000% 1.474%MD 5 5 0 0.474% 0.507% 0.000% 624 624 0 0.012% 0.061% 0.000%ME 1 1 0 0.123% 0.132% 0.000% 45 45 0 0.006% 0.015% 0.000%MI 3 3 0 0.101% 0.103% 0.000% 796 796 0 0.011% 0.040% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 52,612 52,612 0 1.235% 1.747% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 207 207 0 0.027% 0.057% 0.000%NC 7 7 0 0.296% 0.314% 0.000% 4,724 4,724 0 0.068% 0.273% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 0.259% 0.263% 0.000% 387 387 0 0.026% 0.056% 0.000%NH 2 2 0 0.159% 0.164% 0.000% 82 82 0 0.009% 0.021% 0.000%NJ 5 5 0 0.358% 0.367% 0.000% 109,654 109,654 0 1.415% 4.042% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 2 2 0 0.131% 0.155% 0.000% 1,735 1,735 0 0.035% 0.166% 0.000%OH 2 1 1 0.103% 0.055% 0.800% 211 125 86 0.002% 0.004% 0.001%OK 5 5 0 0.685% 0.965% 0.000% 3,765 3,765 0 0.121% 0.566% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 7 7 0 0.141% 0.152% 0.000% 21,871 21,871 0 0.087% 0.235% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.070% 0.000% 80 80 0 0.002% 0.013% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.112% 0.113% 0.000% 840 840 0 0.021% 0.036% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 66 58 8 0.131% 0.126% 0.188% 4,750,603 337,994 4,412,609 2.093% 0.391% 3.140%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A24e. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 2 1 1 0.323% 0.211% 0.685% 33,311 9,046 24,265 5.495% 3.889% 6.495%AL 4 4 0 1.521% 1.980% 0.000% 101,319 101,319 0 2.402% 9.021% 0.000%AR 1 1 0 0.220% 0.262% 0.000% 240 240 0 0.010% 0.026% 0.000%AZ 2 2 0 0.189% 0.198% 0.000% 7,690 7,690 0 0.125% 0.275% 0.000%CA 19 12 7 0.520% 0.383% 1.354% 5,136,792 247,386 4,889,406 14.337% 1.830% 21.913%CO 1 1 0 0.121% 0.165% 0.000% 40 40 0 0.001% 0.008% 0.000%CT 3 2 1 0.249% 0.171% 2.564% 35,983 250 35,733 1.321% 0.064% 1.531%DE 1 0 1 0.314% 0.000% 33.333% 36,130 0 36,130 5.169% 0.000% 12.839%FL 1 1 0 0.066% 0.067% 0.000% 1,400 1,400 0 0.008% 0.009% 0.000%GA 5 4 1 0.274% 0.234% 0.862% 7,870 3,120 4,750 0.105% 0.196% 0.081%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 1 1 0 0.095% 0.098% 0.000% 372 372 0 0.015% 0.026% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 1 1 0 0.068% 0.070% 0.000% 113,400 113,400 0 2.318% 4.410% 0.000%KY 1 0 1 0.415% 0.000% 0.671% 48,800 0 48,800 1.060% 0.000% 1.154%MA 8 3 5 1.114% 0.500% 4.237% 192,347 37,968 154,379 2.248% 2.170% 2.268%MD 9 7 2 0.854% 0.710% 2.941% 109,717 3,634 106,083 2.184% 0.354% 2.653%ME 3 3 0 0.370% 0.396% 0.000% 1,198 1,198 0 0.164% 0.409% 0.000%MI 4 4 0 0.135% 0.137% 0.000% 2,554 2,554 0 0.036% 0.129% 0.000%MN 5 5 0 0.316% 0.322% 0.000% 54,141 54,141 0 1.271% 1.798% 0.000%MO 2 2 0 0.141% 0.149% 0.000% 720 720 0 0.024% 0.043% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 207 207 0 0.027% 0.057% 0.000%NC 13 13 0 0.549% 0.583% 0.000% 6,561 6,561 0 0.094% 0.379% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 11 11 0 1.427% 1.447% 0.000% 27,686 27,686 0 1.893% 4.038% 0.000%NH 6 6 0 0.477% 0.493% 0.000% 19,230 19,230 0 2.027% 4.820% 0.000%NJ 13 12 1 0.930% 0.882% 2.703% 248,452 171,795 76,657 3.206% 6.333% 1.522%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 3 3 0 0.197% 0.233% 0.000% 5,809 5,809 0 0.119% 0.556% 0.000%OH 3 1 2 0.154% 0.055% 1.600% 19,181 125 19,056 0.188% 0.004% 0.269%OK 11 11 0 1.507% 2.124% 0.000% 5,424 5,424 0 0.174% 0.816% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 3 2 1 0.366% 0.264% 1.613% 8,589 209 8,380 0.256% 0.029% 0.319%SD 1 1 0 0.408% 0.429% 0.000% 770 770 0 0.289% 0.396% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 11 10 1 0.222% 0.217% 0.292% 49,470 26,470 23,000 0.197% 0.285% 0.145%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 7 7 0 0.438% 0.490% 0.000% 1,712 1,712 0 0.032% 0.271% 0.000%VT 2 2 0 0.332% 0.357% 0.000% 4,746 4,746 0 0.967% 2.090% 0.000%WI 5 5 0 0.280% 0.283% 0.000% 3,276 3,276 0 0.081% 0.140% 0.000%WV 1 0 1 0.248% 0.000% 0.625% 1,800 0 1,800 0.127% 0.000% 0.153%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 164 139 25 0.325% 0.301% 0.587% 6,286,937 858,498 5,428,439 2.770% 0.994% 3.863%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A24f. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 5 2 3 0.806% 0.422% 2.055% 34,651 9,211 25,440 5.716% 3.960% 6.809%AL 6 6 0 2.281% 2.970% 0.000% 127,086 127,086 0 3.013% 11.315% 0.000%AR 1 1 0 0.220% 0.262% 0.000% 240 240 0 0.010% 0.026% 0.000%AZ 4 4 0 0.378% 0.396% 0.000% 8,376 8,376 0 0.136% 0.300% 0.000%CA 30 19 11 0.821% 0.606% 2.128% 6,711,489 394,381 6,317,108 18.732% 2.918% 28.312%CO 1 1 0 0.121% 0.165% 0.000% 40 40 0 0.001% 0.008% 0.000%CT 6 5 1 0.497% 0.428% 2.564% 36,153 420 35,733 1.328% 0.108% 1.531%DE 4 3 1 1.258% 0.952% 33.333% 37,104 974 36,130 5.308% 0.233% 12.839%FL 1 1 0 0.066% 0.067% 0.000% 1,400 1,400 0 0.008% 0.009% 0.000%GA 6 5 1 0.329% 0.293% 0.862% 8,990 4,240 4,750 0.120% 0.266% 0.081%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 4 4 0 0.379% 0.391% 0.000% 1,533 1,533 0 0.060% 0.107% 0.000%ID 1 1 0 0.107% 0.114% 0.000% 490 490 0 0.045% 0.059% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 1,059 1,059 0 0.011% 0.035% 0.000%IN 2 1 1 0.136% 0.070% 2.273% 376,920 113,400 263,520 7.706% 4.410% 11.360%KY 1 0 1 0.415% 0.000% 0.671% 48,800 0 48,800 1.060% 0.000% 1.154%MA 13 6 7 1.811% 1.000% 5.932% 243,849 50,023 193,826 2.850% 2.859% 2.847%MD 12 10 2 1.139% 1.014% 2.941% 112,146 6,063 106,083 2.232% 0.591% 2.653%ME 3 3 0 0.370% 0.396% 0.000% 1,198 1,198 0 0.164% 0.409% 0.000%MI 6 6 0 0.202% 0.206% 0.000% 10,436 10,436 0 0.146% 0.528% 0.000%MN 8 8 0 0.506% 0.515% 0.000% 59,856 59,856 0 1.405% 1.988% 0.000%MO 3 3 0 0.212% 0.224% 0.000% 2,720 2,720 0 0.091% 0.161% 0.000%MT 3 3 0 0.354% 0.381% 0.000% 384 384 0 0.051% 0.105% 0.000%NC 22 21 1 0.929% 0.943% 0.719% 14,730 9,292 5,438 0.210% 0.536% 0.103%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 13 13 0 1.686% 1.711% 0.000% 34,402 34,402 0 2.353% 5.017% 0.000%NH 9 9 0 0.715% 0.740% 0.000% 19,770 19,770 0 2.084% 4.955% 0.000%NJ 19 16 3 1.359% 1.176% 8.108% 554,311 177,114 377,197 7.154% 6.529% 7.490%NM 2 1 1 0.275% 0.145% 2.564% 101,451 28,750 72,701 5.971% 2.007% 27.275%NV 1 1 0 0.296% 0.315% 0.000% 427 427 0 0.044% 0.151% 0.000%NY 4 4 0 0.262% 0.310% 0.000% 6,309 6,309 0 0.129% 0.604% 0.000%OH 5 3 2 0.257% 0.165% 1.600% 19,506 450 19,056 0.191% 0.014% 0.269%OK 19 18 1 2.603% 3.475% 0.472% 83,183 76,713 6,470 2.663% 11.539% 0.263%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 4 2 2 0.488% 0.264% 3.226% 9,239 209 9,030 0.275% 0.029% 0.344%SD 1 1 0 0.408% 0.429% 0.000% 770 770 0 0.289% 0.396% 0.000%TN 2 1 1 0.570% 0.617% 0.529% 11,004 5,254 5,750 0.194% 0.359% 0.136%TX 11 10 1 0.222% 0.217% 0.292% 49,470 26,470 23,000 0.197% 0.285% 0.145%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 9 9 0 0.563% 0.630% 0.000% 2,762 2,762 0 0.052% 0.438% 0.000%VT 4 4 0 0.663% 0.714% 0.000% 4,915 4,915 0 1.001% 2.165% 0.000%WI 8 8 0 0.448% 0.454% 0.000% 212,465 212,465 0 5.260% 9.050% 0.000%WV 1 0 1 0.248% 0.000% 0.625% 1,800 0 1,800 0.127% 0.000% 0.153%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 255 214 41 0.506% 0.463% 0.963% 8,951,434 1,399,602 7,551,832 3.945% 1.620% 5.373%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A25. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 7 μg/L 46,171 24 0.052% 86,395,257 261,170 0.302%

	
 46,171 52 0.113% 86,395,257 922,641 1.068%

> 7 μg/L 4,254 9 0.212% 140,514,407 5,451,023 3.879%

	
 4,254 16 0.376% 140,514,407 6,853,605 4.878%

> 7 μg/L 50,425 33 0.065% 226,909,664 5,712,193 2.517%

	
 50,425 68 0.135% 226,909,664 7,776,246 3.427%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A25a. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,100 1,963 1,137 0.032% 0.000% 0.088% 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8AL 879 647 232 8.987% 10.201% 5.603% 0.5 0.5 0.5 1.33 1.685 1.01 6.8 7.1 1.63 20 20 1.67AR 2,383 1,915 468 0.042% 0.000% 0.214% 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12AZ 12,599 9,538 3,061 0.667% 0.849% 0.098% 0.31 0.31 0.5 0.76 0.8 0.5 3.4 3.4 0.5 5.4 5.4 0.5CA 90,526 47,264 43,262 4.752% 2.272% 7.462% 0.31 0.31 0.5 2.1 1.5 2.25 9.3 21 7.94 67 64 67CO 2,863 2,124 739 0.140% 0.094% 0.271% 0.13 0.13 0.2 0.25 0.215 0.36 0.52 0.3 0.52 0.52 0.3 0.52CT 6,936 6,045 891 0.793% 0.562% 2.357% 0.2 0.53 0.2 1.2 2.15 0.7 4.3 7.5 1.3 15 15 1.7DE 1,048 1,018 30 0.095% 0.098% 0.000% 0.56 0.56 0.56 0.56 0.56 0.56 0.56 0.56FL 4,165 4,098 67 1.273% 1.293% 0.000% 0.14 0.14 1.2 1.2 3.57 3.57 9 9GA 7,175 6,349 826 0.223% 0.252% 0.000% 0.52 0.52 0.685 0.685 0.74 0.74 0.78 0.78HI 1,791 1,688 103 0.000% 0.000% 0.000%IA 1,761 1,636 125 0.000% 0.000% 0.000%ID 3,758 3,297 461 0.027% 0.030% 0.000% 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3IL 7,007 6,447 560 0.371% 0.403% 0.000% 0.37 0.37 0.8 0.8 2.38 2.38 3.92 3.92IN 4,620 4,311 309 0.065% 0.070% 0.000% 0.6 0.6 0.6 0.6 0.99 0.99 0.99 0.99KY 3,308 1,124 2,184 0.121% 0.000% 0.183% 0.5 0.5 0.5 0.5 1 1 1 1MA 16,249 12,259 3,990 0.831% 0.653% 1.378% 0.4 0.4 0.5 1.2 1.05 1.6 6 5.25 13 18 15 18MD 6,773 5,511 1,262 0.664% 0.581% 1.030% 0.5 0.5 0.6 0.8 0.8 0.9 1.8 1 1.8 3.8 3.8 3.8ME 3,698 3,383 315 0.135% 0.148% 0.000% 0.5 0.5 6.1 6.1 8 8 8 8MI 10,752 9,742 1,010 0.009% 0.010% 0.000% 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7MN 8,582 7,333 1,249 0.245% 0.286% 0.000% 0.5 0.5 0.7 0.7 1.1 1.1 1.9 1.9MO 7,544 6,695 849 0.133% 0.149% 0.000% 0.52 0.52 0.72 0.72 1.465 1.465 1.7 1.7MT 4,492 3,953 539 0.067% 0.076% 0.000% 0.65 0.65 1.6 1.6 2.3 2.3 2.3 2.3NC 19,067 17,487 1,580 0.850% 0.921% 0.063% 0.5 0.5 5.4 1.2 1.2 5.4 5.4 5 5.4 214 214 5.4ND 552 417 135 0.000% 0.000% 0.000%NE 6,844 6,265 579 0.628% 0.686% 0.000% 0.12 0.12 0.86 0.86 3.2 3.2 13 13NH 9,590 9,112 478 0.469% 0.428% 1.255% 0.5 0.5 1 1.6 1.4 2.35 3.1 3.3 3.1 6.09 6.09 3.1NJ 20,354 18,566 1,788 0.889% 0.899% 0.783% 0.2 0.2 0.5 0.74 0.8 0.6 2.1 2.17 1.1 23.16 23.16 1.7NM 6,578 6,102 476 0.517% 0.557% 0.000% 0.2 0.2 0.5 0.5 1.12 1.12 1.532 1.532NV 3,192 2,570 622 0.407% 0.506% 0.000% 0.5 0.5 0.81 0.81 1.03 1.03 5.88 5.88NY 7,069 5,404 1,665 0.481% 0.574% 0.180% 0.5 0.5 0.5 3.55 5.4 0.5 8.9 8.9 1.2 12 12 1.2OH 8,808 7,672 1,136 0.045% 0.039% 0.088% 0.6 0.6 0.97 0.835 0.7 0.97 2.44 2.44 0.97 2.44 2.44 0.97OK 5,636 4,201 1,435 0.497% 0.643% 0.070% 0.49 0.49 0.5 0.675 0.7 0.5 1.1 1.1 0.5 2 2 0.5OR 2,327 1,684 643 0.473% 0.653% 0.000% 0.5 0.5 0.8 0.8 1 1 1.1 1.1RI 1,959 1,591 368 1.225% 1.508% 0.000% 0.5 0.5 0.84 0.84 1.5 1.5 3 3SC 4,343 3,804 539 0.806% 0.920% 0.000% 0.5 0.5 1.23 1.23 3.71 3.71 10.9 10.9SD 889 855 34 0.000% 0.000% 0.000%TN 2,946 1,166 1,780 0.407% 1.029% 0.000% 0.7 0.7 1.4 1.4 4.9 4.9 5 5TX 34,148 27,044 7,104 0.143% 0.181% 0.000% 0.6 0.6 2.1 2.1 8.1 8.1 10 10UT 8,991 7,560 1,431 0.145% 0.172% 0.000% 0.5 0.5 0.6 0.6 2.3 2.3 2.3 2.3VA 4,895 4,028 867 1.021% 1.241% 0.000% 0.5 0.5 1 1 4.85 4.85 6.6 6.6VT 4,344 3,953 391 0.552% 0.607% 0.000% 0.6 0.6 1.8 1.8 2 2 3 3WI 11,292 11,167 125 0.708% 0.716% 0.000% 0.054 0.054 0.602 0.602 7.9 7.9 13 13WV 1,138 443 695 1.582% 2.483% 1.007% 0.08 0.08 0.3 0.5 0.5 1 1.1 0.5 1.2 1.2 0.9 1.2WY 1,659 1,156 503 0.000% 0.000% 0.000%Total 378,630 290,587 88,043 1.508% 0.804% 3.832% 0.054 0.054 0.12 1.7 1.1 2.145 8 8.4 7.9 214 214 67

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A25b. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.161% 0.000% 0.685% 0.004% 0.000% 0.007%AL 263 202 61 4,218,278 1,123,190 3,095,088 3.042% 2.970% 3.279% 7.889% 5.885% 8.616%AR 454 382 72 2,453,348 910,322 1,543,026 0.220% 0.000% 1.389% 0.594% 0.000% 0.944%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.472% 0.396% 2.083% 5.828% 2.125% 8.901%CA 3,649 3,134 515 35,802,195 13,515,377 22,286,818 1.809% 1.436% 4.078% 25.966% 12.796% 33.952%CO 826 605 221 4,997,841 530,207 4,467,634 0.484% 0.331% 0.905% 0.084% 0.739% 0.006%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 1.077% 0.942% 5.128% 3.317% 0.891% 3.722%DE 318 315 3 698,987 417,587 281,400 0.314% 0.317% 0.000% 0.020% 0.034% 0.000%FL 1,510 1,484 26 17,497,764 15,251,722 2,246,042 0.728% 0.741% 0.000% 3.713% 4.260% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.110% 0.117% 0.000% 0.014% 0.064% 0.000%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.107% 0.114% 0.000% 0.073% 0.096% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.140% 0.151% 0.000% 1.689% 5.161% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.204% 0.210% 0.000% 1.192% 2.267% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 1.660% 0.000% 2.685% 2.376% 0.000% 2.587%MA 718 600 118 8,557,325 1,749,901 6,807,424 2.089% 2.167% 1.695% 1.763% 7.102% 0.390%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.474% 0.406% 1.471% 0.277% 0.968% 0.100%ME 810 757 53 728,347 292,773 435,574 0.370% 0.396% 0.000% 0.058% 0.145% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.034% 0.034% 0.000% 0.001% 0.002% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.253% 0.258% 0.000% 1.757% 2.487% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.141% 0.149% 0.000% 0.068% 0.120% 0.000%MT 848 788 60 757,949 365,280 392,669 0.118% 0.127% 0.000% 0.013% 0.026% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 1.352% 1.391% 0.719% 0.861% 2.040% 0.472%ND 210 183 27 562,397 257,172 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 771 760 11 1,462,181 685,701 776,480 1.167% 1.184% 0.000% 6.397% 13.640% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 1.113% 1.068% 2.439% 1.436% 0.281% 2.274%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 3.433% 3.306% 8.108% 11.276% 8.391% 12.829%NM 727 688 39 1,698,980 1,432,432 266,548 0.825% 0.872% 0.000% 28.983% 34.376% 0.000%NV 338 317 21 973,592 283,701 689,891 0.888% 0.946% 0.000% 0.057% 0.195% 0.000%NY 1,520 1,284 236 4,894,535 1,043,933 3,850,602 0.592% 0.467% 1.271% 5.876% 1.566% 7.045%OH 1,943 1,818 125 10,227,535 3,132,598 7,094,937 0.154% 0.110% 0.800% 0.003% 0.003% 0.003%OK 730 518 212 3,123,687 664,833 2,458,854 0.959% 1.158% 0.472% 2.565% 0.834% 3.033%OR 1,098 946 152 2,940,189 574,759 2,365,430 0.182% 0.211% 0.000% 1.039% 5.316% 0.000%RI 145 136 9 913,884 173,906 739,978 2.069% 2.206% 0.000% 0.537% 2.823% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 1.099% 1.189% 0.000% 0.271% 1.242% 0.000%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.570% 1.235% 0.000% 0.120% 0.466% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.162% 0.174% 0.000% 0.016% 0.042% 0.000%UT 500 454 46 2,553,197 1,698,877 854,320 0.200% 0.220% 0.000% 0.051% 0.077% 0.000%VA 1,590 1,420 170 5,269,789 628,354 4,641,435 0.503% 0.563% 0.000% 0.024% 0.200% 0.000%VT 603 560 43 491,035 227,067 263,968 0.663% 0.714% 0.000% 0.062% 0.133% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.673% 0.680% 0.000% 2.965% 5.102% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.260% 1.418% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,425 46,171 4,254 226,909,664 86,395,257 140,514,407 0.688% 0.643% 1.175% 5.917% 4.623% 6.713%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A25c. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 2 2 0 0.760% 0.990% 0.000% 16,437 16,437 0 0.390% 1.463% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 12 4 8 0.329% 0.128% 1.553% 5,568,022 140,423 5,427,599 15.552% 1.039% 24.353%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 60 60 0 0.002% 0.015% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.066% 0.067% 0.000% 2,250 2,250 0 0.013% 0.015% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 3 2 1 0.418% 0.333% 0.847% 51,664 28,240 23,424 0.604% 1.614% 0.344%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 1 1 0 0.123% 0.132% 0.000% 150 150 0 0.021% 0.051% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 4 4 0 0.169% 0.180% 0.000% 3,837 3,837 0 0.055% 0.221% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 1 1 0 0.130% 0.132% 0.000% 40,311 40,311 0 2.757% 5.879% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 2 2 0 0.143% 0.147% 0.000% 151 151 0 0.002% 0.006% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 13,500 13,500 0 0.276% 1.293% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 1 0 0.122% 0.132% 0.000% 111 111 0 0.003% 0.015% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 2 2 0 0.040% 0.043% 0.000% 2,390 2,390 0 0.010% 0.026% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.056% 0.057% 0.000% 13,310 13,310 0 0.329% 0.567% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 33 24 9 0.065% 0.052% 0.212% 5,712,193 261,170 5,451,023 2.517% 0.302% 3.879%

Percent of Population Served 

with At Least One Detection 

> 7 μg/L

State

Number of Systems 

with At Least One Detection 

> 7 μg/L

Percent of Systems 

with At Least One Detection 

> 7 μg/L

Population Served by Systems 

with At Least One Detection 

> 7 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A25d. 1,1-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 2 2 0 0.760% 0.990% 0.000% 16,437 16,437 0 0.390% 1.463% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 350 350 0 0.006% 0.013% 0.000%CA 22 9 13 0.603% 0.287% 2.524% 7,118,411 317,104 6,801,307 19.883% 2.346% 30.517%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 3 3 0 0.249% 0.257% 0.000% 90 90 0 0.003% 0.023% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 2 2 0 0.132% 0.135% 0.000% 317,766 317,766 0 1.816% 2.083% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 155,650 155,650 0 1.689% 5.159% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 3 2 1 0.418% 0.333% 0.847% 51,664 28,240 23,424 0.604% 1.614% 0.344%MD 2 1 1 0.190% 0.101% 1.471% 10,200 6,200 4,000 0.203% 0.605% 0.100%ME 1 1 0 0.123% 0.132% 0.000% 150 150 0 0.021% 0.051% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 9 8 1 0.380% 0.359% 0.719% 31,405 6,531 24,874 0.449% 0.377% 0.472%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 0.259% 0.263% 0.000% 40,911 40,911 0 2.798% 5.966% 0.000%NH 2 2 0 0.159% 0.164% 0.000% 90 90 0 0.009% 0.023% 0.000%NJ 4 4 0 0.286% 0.294% 0.000% 1,191 1,191 0 0.015% 0.044% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 1 0 0.296% 0.315% 0.000% 427 427 0 0.044% 0.151% 0.000%NY 2 2 0 0.132% 0.156% 0.000% 13,550 13,550 0 0.277% 1.298% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 2 2 0 0.244% 0.264% 0.000% 166 166 0 0.005% 0.023% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 1 0 0.285% 0.617% 0.000% 1,519 1,519 0 0.027% 0.104% 0.000%TX 4 4 0 0.081% 0.087% 0.000% 2,461 2,461 0 0.010% 0.026% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 3 3 0 0.189% 0.211% 0.000% 498 498 0 0.009% 0.079% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.056% 0.057% 0.000% 13,310 13,310 0 0.329% 0.567% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 68 52 16 0.135% 0.113% 0.376% 7,776,246 922,641 6,853,605 3.427% 1.068% 4.878%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A26. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 70 μg/L 46,072 3 0.007% 85,155,955 37,997 0.045%

	
 46,072 10 0.022% 85,155,955 218,371 0.256%

> 70 μg/L 4,242 2 0.047% 140,459,779 128,756 0.092%

	
 4,242 3 0.071% 140,459,779 328,756 0.234%

> 70 μg/L 50,314 5 0.010% 225,615,734 166,753 0.074%

	
 50,314 13 0.026% 225,615,734 547,127 0.243%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A26a. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,107 1,969 1,138 0.064% 0.102% 0.000% 0.57 0.57 0.605 0.605 0.64 0.64 0.64 0.64AL 894 628 266 9.843% 5.892% 19.173% 0.23 0.23 0.5 0.8 0.8 0.7 4.5 1.3 4.66 14.1 2.6 14.1AR 2,394 1,926 468 0.668% 0.831% 0.000% 0.18 0.18 0.52 0.52 0.9 0.9 0.95 0.95AZ 11,710 9,530 2,180 0.999% 1.196% 0.138% 0.5 0.5 0.5 2 2 0.5 3.2 3.2 0.5 4.4 4.4 0.5CA 87,763 45,927 41,836 3.989% 3.244% 4.807% 0.21 0.21 0.4 1 0.9 1.3 4.2 3.4 4.53 160 33.2 160CO 2,871 2,132 739 0.348% 0.422% 0.135% 1.1 6.3 1.1 9.05 10 1.1 12 12 1.1 12 12 1.1CT 6,936 6,045 891 1.312% 1.175% 2.245% 0.3 0.51 0.3 1.5 3.1 0.8 8.4 9.8 1.8 39 39 2DE 1,053 1,023 30 0.760% 0.782% 0.000% 0.85 0.85 0.91 0.91 1.12 1.12 1.12 1.12FL 4,160 4,092 68 4.663% 4.741% 0.000% 0.09 0.09 0.685 0.685 8.1 8.1 29 29GA 7,174 6,347 827 0.251% 0.047% 1.814% 0.5 0.51 0.5 1 0.56 1.1 1.6 0.57 1.6 1.8 0.57 1.8HIIA 1,812 1,671 141 2.373% 2.095% 5.674% 0.5 0.5 0.5 1.3 1.4 1.2 2 2.2 1.4 6.2 6.2 1.4ID 3,764 3,303 461 0.478% 0.545% 0.000% 0.1 0.1 0.9 0.9 1.2 1.2 1.5 1.5IL 7,045 6,485 560 3.520% 3.824% 0.000% 0.5 0.5 1.64 1.64 7.3 7.3 21 21IN 4,621 4,311 310 0.887% 0.719% 3.226% 0.5 0.6 0.5 1.2 1.6 0.595 8.7 10 1.15 13.3 13.3 1.2KY 3,309 1,126 2,183 0.272% 0.000% 0.412% 0.008 0.008 0.5 0.5 1 1 1 1MA 16,249 12,259 3,990 1.988% 1.158% 4.536% 0.5 0.5 0.5 2.2 1.4 3.2 29 50 13 151 151 108MD 6,770 5,510 1,260 0.665% 0.799% 0.079% 0.8 0.8 1.6 3.4 3.45 1.6 8.8 8.8 1.6 10.6 10.6 1.6ME 3,688 3,373 315 0.027% 0.030% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5MI 10,750 9,740 1,010 3.163% 3.460% 0.297% 0.4 0.4 0.4 1.2 1.3 0.4 4.5 4.5 0.4 46.2 46.2 0.4MN 8,590 7,341 1,249 1.467% 1.689% 0.160% 0.2 0.2 0.4 0.9 0.9 0.4 5.5 5.5 0.4 24 24 0.4MO 7,544 6,695 849 0.557% 0.627% 0.000% 0.5 0.5 1.085 1.085 1.45 1.45 1.6 1.6MT 4,491 3,951 540 0.134% 0.152% 0.000% 1.5 1.5 2.35 2.35 3.7 3.7 3.7 3.7NC 19,067 17,487 1,580 0.645% 0.703% 0.000% 0.5 0.5 1.3 1.3 7.88 7.88 70 70ND 558 417 141 1.971% 0.719% 5.674% 0.5 0.5 1.33 1.53 1.03 1.86 2.09 1.12 2.86 2.86 1.12 2.86NE 6,841 6,265 576 0.599% 0.654% 0.000% 0.1 0.1 0.7 0.7 3 3 8.5 8.5NH 9,602 9,124 478 1.208% 1.260% 0.209% 0.05 0.05 1.4 1.65 1.7 1.4 7.6 7.6 1.4 31 31 1.4NJ 20,341 18,553 1,788 1.863% 1.692% 3.635% 0.1 0.1 0.2 1 1 0.96 4.85 5.67 1.4 61 61 2.3NM 6,577 6,101 476 0.334% 0.361% 0.000% 0.1 0.1 0.185 0.185 0.3 0.3 0.4 0.4NV 3,208 2,576 632 0.000% 0.000% 0.000%NY 7,066 5,400 1,666 2.038% 1.315% 4.382% 0.3 0.3 0.5 1.25 1.2 1.3 2.9 2.3 3.2 20 20 4.3OH 8,853 7,692 1,161 2.869% 1.859% 9.561% 0.25 0.5 0.25 0.67 1.2 0.45 2.3 3.2 0.63 15 15 0.8OK 5,637 4,201 1,436 0.781% 1.047% 0.000% 0.5 0.5 0.9 0.9 1.5 1.5 4.24 4.24OR 2,324 1,682 642 0.516% 0.713% 0.000% 0.5 0.5 0.65 0.65 1 1 3.1 3.1RI 1,959 1,591 368 0.715% 0.880% 0.000% 0.6 0.6 1 1 1.6 1.6 4.7 4.7SC 4,345 3,805 540 0.207% 0.237% 0.000% 0.62 0.62 0.7 0.7 2.28 2.28 2.28 2.28SD 889 855 34 0.225% 0.234% 0.000% 0.52 0.52 0.53 0.53 0.54 0.54 0.54 0.54TN 2,946 1,166 1,780 0.441% 1.115% 0.000% 0.6 0.6 0.93 0.93 1.7 1.7 1.8 1.8TX 34,144 27,040 7,104 0.070% 0.067% 0.084% 0.5 0.5 1.1 1 0.9 1.35 1.7 1.7 1.9 120 120 1.9UT 8,987 7,556 1,431 0.000% 0.000% 0.000%VA 4,892 4,024 868 0.899% 0.646% 2.074% 0.5 0.5 1 1.4 0.855 4.75 7.1 2.8 10 11 3.2 11VT 4,342 3,951 391 0.645% 0.709% 0.000% 0.8 0.8 1.85 1.85 2.6 2.6 5.3 5.3WI 11,293 11,168 125 3.090% 3.125% 0.000% 0.01 0.01 1.6 1.6 11 11 220 220WV 1,141 445 696 2.366% 2.921% 2.011% 0.24 0.24 0.5 0.5 0.5 12.75 21.6 0.5 28.4 32.5 0.8 32.5WY 1,609 1,123 486 0.000% 0.000% 0.000%Total 373,316 287,606 85,710 1.860% 1.506% 3.046% 0.008 0.01 0.008 1.1 1 1.2 5 5 5 220 220 160

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A26b. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.161% 0.211% 0.000% 1.492% 3.889% 0.000%AL 263 202 61 4,218,278 1,123,190 3,095,088 1.901% 0.990% 4.918% 8.244% 1.576% 10.664%AR 454 382 72 2,453,348 910,322 1,543,026 0.441% 0.524% 0.000% 0.834% 2.248% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.378% 0.297% 2.083% 5.576% 1.569% 8.901%CA 3,645 3,130 515 35,801,891 13,515,073 22,286,818 1.646% 1.374% 3.301% 24.947% 10.261% 33.853%CO 826 605 221 4,997,841 530,207 4,467,634 0.242% 0.165% 0.452% 0.005% 0.015% 0.004%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 1.408% 1.284% 5.128% 2.997% 1.444% 3.256%DE 318 315 3 698,987 417,587 281,400 0.943% 0.952% 0.000% 1.324% 2.217% 0.000%FL 1,510 1,484 26 17,497,764 15,251,722 2,246,042 1.854% 1.887% 0.000% 8.931% 10.246% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.165% 0.059% 1.724% 1.194% 0.016% 1.513%HIIA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.947% 0.782% 6.061% 14.475% 10.859% 19.155%ID 935 878 57 1,093,666 837,604 256,062 0.321% 0.342% 0.000% 0.856% 1.118% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 1.400% 1.509% 0.000% 3.784% 11.561% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 1.018% 0.909% 4.545% 25.234% 13.988% 37.700%KY 241 92 149 4,602,392 375,363 4,227,029 3.320% 0.000% 5.369% 8.306% 0.000% 9.044%MA 718 600 118 8,557,325 1,749,901 6,807,424 3.064% 2.667% 5.085% 4.220% 12.827% 2.008%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.759% 0.710% 1.471% 0.530% 2.003% 0.153%ME 810 757 53 728,347 292,773 435,574 0.123% 0.132% 0.000% 0.030% 0.073% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.606% 0.584% 1.639% 5.197% 17.349% 0.557%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 1.391% 1.289% 6.667% 8.102% 11.062% 0.968%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.353% 0.373% 0.000% 1.430% 2.543% 0.000%MT 848 788 60 757,949 365,280 392,669 0.118% 0.127% 0.000% 0.027% 0.057% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.845% 0.898% 0.000% 0.193% 0.778% 0.000%ND 210 183 27 562,397 257,172 305,225 0.952% 0.546% 3.704% 1.919% 1.543% 2.236%NE 771 760 11 1,462,181 685,701 776,480 0.908% 0.921% 0.000% 4.521% 9.641% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 1.351% 1.315% 2.439% 5.332% 5.661% 5.093%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 4.649% 4.409% 13.514% 21.630% 19.964% 22.527%NM 727 688 39 1,698,980 1,432,432 266,548 0.413% 0.436% 0.000% 27.250% 32.320% 0.000%NV 338 317 21 973,592 283,701 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,520 1,284 236 4,894,535 1,043,933 3,850,602 1.118% 1.090% 1.271% 7.137% 7.479% 7.045%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 1.080% 1.100% 0.800% 3.537% 4.669% 3.038%OK 730 518 212 3,123,687 664,833 2,458,854 0.548% 0.772% 0.000% 0.260% 1.221% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.456% 0.529% 0.000% 0.017% 0.088% 0.000%RI 145 136 9 913,884 173,906 739,978 1.379% 1.471% 0.000% 0.143% 0.753% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.366% 0.396% 0.000% 0.155% 0.708% 0.000%SD 245 233 12 266,416 194,218 72,198 0.408% 0.429% 0.000% 0.724% 0.994% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.285% 0.617% 0.000% 0.063% 0.247% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.121% 0.108% 0.292% 2.760% 0.053% 4.352%UT 500 454 46 2,553,197 1,698,877 854,320 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 1,589 1,419 170 5,269,916 628,481 4,641,435 0.441% 0.423% 0.588% 0.153% 0.284% 0.136%VT 603 560 43 491,035 227,067 263,968 0.332% 0.357% 0.000% 0.967% 2.090% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 1.570% 1.587% 0.000% 9.779% 16.825% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.970% 5.350% 1.875% 2.726% 4.193% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,314 46,072 4,242 225,615,734 85,155,955 140,459,779 0.964% 0.914% 1.509% 8.438% 7.828% 8.808%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A26c. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 0 1 0.027% 0.000% 0.194% 105,332 0 105,332 0.294% 0.000% 0.473%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 2 1 1 0.279% 0.167% 0.847% 32,359 8,935 23,424 0.378% 0.511% 0.344%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 119 119 0 0.000% 0.001% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.056% 0.057% 0.000% 28,943 28,943 0 0.716% 1.233% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 5 3 2 0.010% 0.007% 0.047% 166,753 37,997 128,756 0.074% 0.045% 0.092%

Percent of Population Served 

with At Least One Detection 

> 70 μg/L

State

Number of Systems 

with At Least One Detection 

> 70 μg/L

Percent of Systems 

with At Least One Detection 

> 70 μg/L

Population Served by Systems 

with At Least One Detection 

> 70 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A26d. cis-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 2 0 2 0.055% 0.000% 0.388% 305,332 0 305,332 0.853% 0.000% 1.370%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 280 280 0 0.010% 0.072% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 2 1 1 0.279% 0.167% 0.847% 32,359 8,935 23,424 0.378% 0.511% 0.344%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 2 2 0 0.067% 0.069% 0.000% 177,923 177,923 0 2.486% 8.996% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 2 0 0.084% 0.090% 0.000% 2,131 2,131 0 0.030% 0.123% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 1 1 0 0.072% 0.073% 0.000% 40 40 0 0.001% 0.001% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 119 119 0 0.000% 0.001% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.056% 0.057% 0.000% 28,943 28,943 0 0.716% 1.233% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 13 10 3 0.026% 0.022% 0.071% 547,127 218,371 328,756 0.243% 0.256% 0.234%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A27. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 100 μg/L 46,078 0 0.000% 85,155,343 0 0.000%

	
 46,078 0 0.000% 85,155,343 0 0.000%

> 100 μg/L 4,241 0 0.000% 140,455,794 0 0.000%

	
 4,241 0 0.000% 140,455,794 0 0.000%

> 100 μg/L 50,319 0 0.000% 225,611,137 0 0.000%

	
 50,319 0 0.000% 225,611,137 0 0.000%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A27a. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,108 1,970 1,138 0.032% 0.051% 0.000% 1.04 1.04 1.04 1.04 1.04 1.04 1.04 1.04AL 820 596 224 0.000% 0.000% 0.000%AR 2,393 1,926 467 0.000% 0.000% 0.000%AZ 11,685 9,519 2,166 0.051% 0.032% 0.139% 0.5 2.2 0.5 1.35 2.7 0.5 3.2 3.2 0.5 3.2 3.2 0.5CA 85,900 45,408 40,492 0.290% 0.044% 0.566% 0.51 0.51 0.6 1.2 0.79 1.2 6.9 1.1 7 17 1.9 17CO 2,866 2,127 739 0.035% 0.047% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5CT 6,935 6,044 891 0.043% 0.050% 0.000% 0.51 0.51 0.69 0.69 0.8 0.8 0.8 0.8DE 1,047 1,017 30 0.000% 0.000% 0.000%FL 4,153 4,085 68 0.144% 0.147% 0.000% 0.13 0.13 0.38 0.38 1.6 1.6 1.6 1.6GA 7,174 6,347 827 0.000% 0.000% 0.000%HIIA 1,763 1,638 125 0.000% 0.000% 0.000%ID 3,766 3,305 461 0.053% 0.061% 0.000% 0.6 0.6 0.8 0.8 1 1 1 1IL 6,988 6,428 560 0.057% 0.062% 0.000% 0.51 0.51 1.5 1.5 8.6 8.6 8.6 8.6IN 4,621 4,311 310 0.043% 0.046% 0.000% 0.5 0.5 1.05 1.05 1.6 1.6 1.6 1.6KY 3,309 1,126 2,183 0.151% 0.000% 0.229% 0.5 0.5 0.5 0.5 1 1 1 1MA 16,249 12,259 3,990 0.105% 0.090% 0.150% 0.52 0.6 0.52 0.82 0.9 0.735 1.4 1.4 1 1.6 1.6 1MD 6,772 5,511 1,261 0.015% 0.018% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5ME 3,689 3,374 315 0.027% 0.030% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5MI 10,751 9,741 1,010 0.205% 0.226% 0.000% 0.4 0.4 0.6 0.6 1.3 1.3 1.5 1.5MN 8,581 7,332 1,249 0.711% 0.832% 0.000% 0.1 0.1 0.3 0.3 1 1 2 2MO 7,544 6,695 849 0.000% 0.000% 0.000%MT 4,486 3,948 538 0.000% 0.000% 0.000%NC 19,066 17,486 1,580 0.005% 0.000% 0.063% 6.2 6.2 6.2 6.2 6.2 6.2 6.2 6.2ND 552 417 135 0.000% 0.000% 0.000%NE 6,838 6,262 576 0.132% 0.144% 0.000% 0.27 0.27 0.63 0.63 0.68 0.68 0.68 0.68NH 9,586 9,108 478 0.261% 0.274% 0.000% 0.26 0.26 1.1 1.1 4.7 4.7 24 24NJ 20,358 18,570 1,788 0.044% 0.048% 0.000% 0.19 0.19 0.5 0.5 1 1 1 1NM 6,575 6,100 475 0.000% 0.000% 0.000%NV 3,207 2,575 632 0.000% 0.000% 0.000%NY 7,062 5,397 1,665 0.127% 0.074% 0.300% 0.5 0.5 0.5 0.5 0.5 0.6 11.2 11.2 1.3 11.2 11.2 1.3OH 8,853 7,691 1,162 0.045% 0.052% 0.000% 0.5 0.5 0.59 0.59 1.7 1.7 1.7 1.7OK 5,635 4,200 1,435 0.000% 0.000% 0.000%OR 2,324 1,682 642 0.086% 0.119% 0.000% 0.8 0.8 3.15 3.15 5.5 5.5 5.5 5.5RI 1,959 1,591 368 0.000% 0.000% 0.000%SC 4,345 3,805 540 0.000% 0.000% 0.000%SD 889 855 34 0.000% 0.000% 0.000%TN 2,946 1,166 1,780 0.000% 0.000% 0.000%TX 34,144 27,040 7,104 0.003% 0.004% 0.000% 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.1UT 8,991 7,560 1,431 0.000% 0.000% 0.000%VA 4,892 4,024 868 0.041% 0.050% 0.000% 1.4 1.4 2.45 2.45 3.5 3.5 3.5 3.5VT 4,345 3,954 391 0.023% 0.025% 0.000% 0.98 0.98 0.98 0.98 0.98 0.98 0.98 0.98WI 11,292 11,167 125 0.425% 0.430% 0.000% 0.02 0.02 0.305 0.305 0.7 0.7 2.2 2.2WV 1,140 444 696 1.316% 2.477% 0.575% 0.18 0.18 0.2 0.5 0.5 0.5 0.5 0.5 1 1 0.5 1WY 1,659 1,156 503 0.000% 0.000% 0.000%Total 371,258 286,957 84,301 0.137% 0.089% 0.300% 0.02 0.02 0.2 1 0.6 1.2 6.1 1.5 6.9 24 24 17

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A27b. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.161% 0.211% 0.000% 0.027% 0.071% 0.000%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.189% 0.099% 2.083% 5.569% 1.553% 8.901%CA 3,653 3,138 515 35,803,379 13,516,561 22,286,818 0.192% 0.159% 0.388% 1.693% 2.225% 1.370%CO 826 605 221 4,997,841 530,207 4,467,634 0.121% 0.165% 0.000% 0.005% 0.047% 0.000%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.166% 0.171% 0.000% 0.020% 0.138% 0.000%DE 318 315 3 698,987 417,587 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,510 1,484 26 17,497,764 15,251,722 2,246,042 0.397% 0.404% 0.000% 2.243% 2.573% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.107% 0.114% 0.000% 0.960% 1.254% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.140% 0.151% 0.000% 2.135% 6.524% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.136% 0.140% 0.000% 1.598% 3.039% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 2.075% 0.000% 3.356% 2.420% 0.000% 2.635%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.418% 0.333% 0.847% 0.380% 0.522% 0.344%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.095% 0.101% 0.000% 0.007% 0.035% 0.000%ME 810 757 53 728,347 292,773 435,574 0.123% 0.132% 0.000% 0.030% 0.073% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.101% 0.103% 0.000% 2.574% 9.314% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.442% 0.451% 0.000% 3.645% 5.158% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 848 788 60 757,949 365,280 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.042% 0.000% 0.719% 6.167% 0.000% 8.196%ND 210 183 27 562,397 257,172 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.130% 0.132% 0.000% 1.441% 3.073% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 0.397% 0.411% 0.000% 0.044% 0.105% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 0.429% 0.441% 0.000% 1.447% 4.133% 0.000%NM 727 688 39 1,698,980 1,432,432 266,548 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 338 317 21 973,592 283,701 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,518 1,283 235 4,888,900 1,042,283 3,846,617 0.461% 0.312% 1.277% 5.638% 0.421% 7.052%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.206% 0.220% 0.000% 0.098% 0.320% 0.000%OK 730 518 212 3,123,687 664,833 2,458,854 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.182% 0.212% 0.000% 1.038% 5.312% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.020% 0.022% 0.000% 0.000% 0.001% 0.000%UT 500 454 46 2,553,197 1,698,877 854,320 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 1,588 1,418 170 5,269,466 628,031 4,641,435 0.126% 0.141% 0.000% 0.003% 0.023% 0.000%VT 603 560 43 491,035 227,067 263,968 0.166% 0.179% 0.000% 0.018% 0.040% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.392% 0.397% 0.000% 1.766% 3.039% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.193% 1.018% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,319 46,078 4,241 225,611,137 85,155,343 140,455,794 0.189% 0.171% 0.377% 1.372% 1.908% 1.048%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A27c. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

 Table A27c. trans-1,2-Dichloroethylene – Summary of Stage 1 (Peak) Analyses of Any Detections > 100 μg/L (Single detections > 100 μg/L are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 100 μg/L State

Number of Systems 

with At Least One Detection 

> 100 μg/L

Percent of Systems 

with At Least One Detection 

> 100 μg/L

Population Served by Systems 

with At Least One Detection 

> 100 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A27d. trans-1,2-Dichloroethylene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

 Table A27d. trans-1,2-Dichloroethylene – Summary of Stage 1 (Peak) Analyses of Any Detections 	
	
!!"
#$

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	
 State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 45,918 125 0.272% 86,307,048 426,870 0.495%

	
 45,918 319 0.695% 86,307,048 1,996,422 2.313%

	
 45,918 783 1.705% 86,307,048 4,262,402 4.939%

> 0.5 μg/L 45,918 1,319 2.873% 86,307,048 6,991,178 8.100%

> 5 μg/L 4,251 22 0.518% 140,537,012 2,516,579 1.791%

	
 4,251 79 1.858% 140,537,012 6,112,617 4.349%

	
 4,251 193 4.540% 140,537,012 11,712,322 8.334%

> 0.5 μg/L 4,251 313 7.363% 140,537,012 25,538,096 18.172%

> 5 μg/L 50,169 147 0.293% 226,844,060 2,943,449 1.298%

	
 50,169 398 0.793% 226,844,060 8,109,039 3.575%

	
 50,169 976 1.945% 226,844,060 15,974,724 7.042%

> 0.5 μg/L 50,169 1,632 3.253% 226,844,060 32,529,274 14.340%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water

Table A28. Dichloromethane (Methylene chloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,107 1,969 1,138 4.313% 2.692% 7.118% 0.0041 0.0041 0.22 0.955 0.93 0.97 3.5 3.1 3.8 88 88 8.1AL 868 621 247 7.373% 5.153% 12.955% 0.5 0.51 0.5 1.485 1.78 1.295 3.5 8.64 3.1 9.94 9.94 5.2AR 2,394 1,926 468 1.044% 1.194% 0.427% 0.15 0.15 0.25 0.74 0.74 1.175 1.83 1.8 2.1 3 3 2.1AZ 11,741 9,575 2,166 0.230% 0.178% 0.462% 0.5 0.5 0.5 0.8 0.8 0.65 2.15 3.2 0.95 16 16 1CA 85,326 44,955 40,371 0.484% 0.543% 0.419% 0.2 0.2 0.5 0.9 0.87 1 2.6 2.4 2.7 28 16.5 28CO 2,893 2,135 758 3.111% 3.138% 3.034% 0.04 0.04 0.46 0.585 0.41 1 1.55 1.2 2.9 17 7.4 17CT 6,826 5,936 890 0.278% 0.303% 0.112% 0.51 0.51 1.6 1.4 1.3 1.6 8.3 8.3 1.6 12 12 1.6DE 1,050 1,020 30 0.952% 0.882% 3.333% 0.52 0.52 1.68 0.755 0.73 1.68 2.18 2.68 1.68 2.68 2.68 1.68FL 4,185 4,118 67 2.843% 2.890% 0.000% 0.15 0.15 0.89 0.89 4.34 4.34 29.6 29.6GA 7,171 6,347 824 0.558% 0.504% 0.971% 0.52 0.52 0.52 1.25 1.55 0.8 3.4 3.4 2.4 34 34 2.4HI 1,789 1,686 103 0.000% 0.000% 0.000%IA 1,781 1,656 125 1.179% 1.268% 0.000% 0.65 0.65 1.4 1.4 4.2 4.2 47.9 47.9ID 3,762 3,301 461 0.425% 0.485% 0.000% 0.5 0.5 1.2 1.2 9.96 9.96 19 19IL 6,568 5,995 573 1.629% 1.635% 1.571% 0.5 0.5 0.84 0.8 0.79 0.92 2.11 2.2 1.4 33.8 33.8 1.4IN 4,623 4,313 310 2.271% 2.365% 0.968% 0.01 0.01 0.5 1.1 1.15 0.63 3.7 3.7 0.95 75.3 75.3 0.95KY 3,318 1,128 2,190 2.502% 1.950% 2.785% 0.005 0.5 0.005 0.9 1 0.8 4 6 3 9.6 9.6 8MA 16,249 12,259 3,990 0.431% 0.424% 0.451% 0.4 0.4 0.5 1 0.95 1.35 3.25 3.1 3.8 9.6 9.6 3.8MD 6,770 5,508 1,262 1.285% 1.416% 0.713% 0.5 0.5 0.5 1 1 0.8 13.2 13.2 13.4 115 115 13.4ME 3,698 3,383 315 0.730% 0.709% 0.952% 0.5 0.5 0.6 1.3 1.7 1.2 5.2 5.2 1.3 11 11 1.3MI 10,618 9,608 1,010 0.367% 0.364% 0.396% 0.5 0.5 0.6 0.9 0.9 0.95 2.5 2.3 2.5 55.3 55.3 2.5MN 8,588 7,339 1,249 0.780% 0.722% 1.121% 0.5 0.5 0.5 1.1 1.2 1.1 3.4 3.2 7 31 7 31MO 7,528 6,685 843 0.956% 0.927% 1.186% 0.5 0.51 0.5 1 1 0.9 4.25 3.8 15.15 25.8 16 25.8MT 4,673 3,981 692 5.307% 3.240% 17.197% 0.24 0.24 0.51 1.7 1.7 1.67 5.09 5.8 4.2 20.8 20.8 18NC 19,070 17,489 1,581 0.346% 0.360% 0.190% 0.5 0.5 0.5 1.3 1.3 1.7 8.05 8.05 2.5 182 182 2.5ND 534 405 129 0.749% 0.741% 0.775% 0.52 0.52 0.65 0.65 0.65 0.65 0.81 0.81 0.65 0.81 0.81 0.65NE 6,837 6,261 576 0.044% 0.048% 0.000% 0.39 0.39 0.88 0.88 1.2 1.2 1.2 1.2NH 9,588 9,108 480 0.688% 0.681% 0.833% 0.5 0.5 0.54 1.55 1.55 1.165 6.5 6.5 2.8 40 40 2.8NJ 20,298 18,518 1,780 0.985% 0.999% 0.843% 0.09 0.17 0.09 0.7 0.7 0.7 4.345 4.09 12.8 315.9 315.9 27.1NM 6,574 6,098 476 1.567% 1.427% 3.361% 0.15 0.15 0.18 1.2 1.2 1.3 1.8 1.8 1.92 42 42 2.6NV 3,166 2,546 620 0.695% 0.628% 0.968% 0.5 0.55 0.5 0.75 0.75 0.75 3.1 4.4 3.1 7.5 7.5 3.1NY 7,081 5,420 1,661 0.621% 0.720% 0.301% 0.5 0.5 0.5 0.7 0.7 0.6 1.7 2 1.1 11.4 11.4 1.1OH 8,783 7,632 1,151 1.583% 1.769% 0.348% 0.5 0.5 0.5 0.8 0.8 0.75 3.18 3.18 2.39 51.54 51.54 2.39OK 5,637 4,201 1,436 1.064% 0.738% 2.019% 0.36 0.4 0.36 0.8 0.77 0.9 3.295 2.4 3.3 4.9 4.9 3.6OR 2,324 1,682 642 0.129% 0.059% 0.312% 0.6 0.6 0.6 0.6 0.6 2 3.4 0.6 3.4 3.4 0.6 3.4RI 1,959 1,591 368 0.613% 0.503% 1.087% 0.62 0.62 1.4 2.25 2.4 1.9 3.9 7.4 2.6 7.4 7.4 2.6SC 4,344 3,805 539 0.322% 0.289% 0.557% 0.51 0.51 0.51 0.765 0.67 0.86 4.7 4.7 1.15 18.4 18.4 1.15SD 889 855 34 0.225% 0.234% 0.000% 0.5 0.5 0.515 0.515 0.53 0.53 0.53 0.53TN 2,943 1,164 1,779 0.917% 0.945% 0.899% 0.51 1 0.51 1.3 1.9 0.9 3.5 3.5 2.8 5.6 3.5 5.6TX 34,143 27,032 7,111 0.674% 0.633% 0.830% 0.5 0.5 0.5 0.8 0.9 0.7 2.85 3 2.1 30 30 12UT 8,986 7,560 1,426 0.234% 0.132% 0.771% 0.3 0.3 0.5 0.7 1.05 0.5 5.6 8.95 0.9 11.8 11.8 0.9VA 4,892 4,023 869 0.164% 0.199% 0.000% 0.5 0.5 1.55 1.55 8.9 8.9 8.9 8.9VT 4,345 3,952 393 0.621% 0.658% 0.254% 0.5 0.5 0.6 0.6 0.65 0.6 1.3 1.3 0.6 16.4 16.4 0.6WI 11,288 11,164 124 2.702% 2.705% 2.419% 0.01 0.01 0.79 0.6 0.6 1.37 2.1 2.1 1.45 16 16 1.45WV 1,140 443 697 1.491% 2.709% 0.717% 0.34 0.34 0.5 0.5 0.5 1 3.9 0.82 21.5 21.5 3.9 21.5WY 1,662 1,159 503 1.504% 1.812% 0.795% 0.2 0.6 0.2 3 3 0.71 9.8 8.7 9.8 12.4 12.4 9.8Total 372,009 287,552 84,457 0.882% 0.874% 0.909% 0.0041 0.0041 0.005 0.9 0.9 1 3.4 3.62 3.2 315.9 315.9 31Table A28a. Dichloromethane (Methylene chloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 13.226% 9.072% 26.712% 45.287% 9.269% 67.711%AL 264 202 62 4,224,479 1,123,190 3,101,289 12.500% 9.406% 22.581% 40.094% 14.180% 49.479%AR 454 382 72 2,453,348 910,322 1,543,026 3.524% 3.665% 2.778% 2.048% 2.309% 1.894%AZ 1,058 1,010 48 6,162,837 2,792,246 3,370,591 1.985% 1.485% 12.500% 17.822% 3.918% 29.341%CA 3,659 3,143 516 35,830,016 13,517,625 22,312,391 4.127% 3.404% 8.527% 29.817% 17.555% 37.245%CO 826 605 221 4,997,841 530,207 4,467,634 8.959% 9.587% 7.240% 7.671% 10.453% 7.341%CT 1,200 1,161 39 2,722,518 388,596 2,333,922 0.833% 0.775% 2.564% 0.769% 3.681% 0.284%DE 319 316 3 699,085 417,685 281,400 3.135% 2.848% 33.333% 22.651% 4.393% 49.751%FL 1,512 1,486 26 17,499,838 15,253,796 2,246,042 5.291% 5.384% 0.000% 8.673% 9.950% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 1.262% 1.231% 1.724% 0.731% 2.124% 0.354%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,055 1,022 33 2,543,092 1,434,466 1,108,626 1.706% 1.761% 0.000% 0.758% 1.343% 0.000%ID 935 878 57 1,093,666 837,604 256,062 1.283% 1.367% 0.000% 8.502% 11.101% 0.000%IL 1,181 1,081 100 9,131,338 2,935,560 6,195,778 6.520% 6.290% 9.000% 4.432% 9.218% 2.164%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 4.817% 4.755% 6.818% 4.700% 3.885% 5.604%KY 241 92 149 4,602,392 375,363 4,227,029 18.672% 11.957% 22.819% 22.088% 13.129% 22.884%MA 718 600 118 8,557,325 1,749,901 6,807,424 6.267% 5.667% 9.322% 4.425% 7.880% 3.537%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 3.890% 3.550% 8.824% 42.221% 27.873% 45.901%ME 810 757 53 728,347 292,773 435,574 2.099% 1.849% 5.660% 5.632% 0.878% 8.827%MI 2,964 2,903 61 7,151,842 1,971,986 5,179,856 1.181% 1.068% 6.557% 50.989% 2.586% 69.416%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 2.149% 1.869% 16.667% 8.071% 6.694% 11.387%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 4.305% 3.806% 12.987% 7.238% 6.272% 8.479%MT 848 788 60 757,949 365,280 392,669 12.028% 8.249% 61.667% 54.015% 31.745% 74.731%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 2.028% 2.020% 2.158% 7.255% 3.321% 8.549%ND 209 182 27 562,357 257,132 305,225 1.914% 1.648% 3.704% 3.169% 6.575% 0.299%NE 771 760 11 1,462,181 685,701 776,480 0.389% 0.395% 0.000% 0.138% 0.294% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 3.021% 2.876% 7.317% 26.043% 10.720% 37.163%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 8.512% 8.376% 13.514% 20.368% 10.218% 25.834%NM 727 688 39 1,698,980 1,432,432 266,548 9.216% 8.430% 23.077% 17.492% 10.584% 54.614%NV 338 317 21 973,592 283,701 689,891 4.734% 4.101% 14.286% 9.514% 11.311% 8.775%NY 1,518 1,283 235 4,888,878 1,042,826 3,846,052 1.713% 1.637% 2.128% 0.377% 1.341% 0.116%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 4.990% 5.168% 2.400% 18.193% 3.974% 24.471%OK 730 518 212 3,123,687 664,833 2,458,854 3.151% 3.089% 3.302% 3.386% 9.675% 1.686%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.182% 0.106% 0.658% 0.041% 0.024% 0.045%RI 145 136 9 913,884 173,906 739,978 5.517% 5.147% 11.111% 8.369% 4.728% 9.225%SC 819 757 62 3,356,831 732,879 2,623,952 1.343% 1.189% 3.226% 0.390% 0.724% 0.297%SD 245 233 12 266,416 194,218 72,198 0.816% 0.858% 0.000% 0.819% 1.124% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 3.419% 3.086% 3.704% 5.218% 5.765% 5.029%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 3.434% 2.972% 9.649% 24.661% 18.561% 28.247%UT 500 454 46 2,553,197 1,698,877 854,320 2.200% 1.762% 6.522% 27.126% 8.964% 63.243%VA 1,588 1,418 170 5,270,628 629,193 4,641,435 0.504% 0.564% 0.000% 0.084% 0.701% 0.000%VT 603 560 43 491,035 227,067 263,968 1.824% 1.786% 2.326% 0.528% 1.033% 0.095%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 10.426% 10.431% 10.000% 14.341% 23.153% 2.113%WV 403 243 160 1,416,020 237,670 1,178,350 4.218% 4.938% 3.125% 2.821% 2.860% 2.813%WY 304 256 48 446,177 129,229 316,948 6.908% 6.641% 8.333% 8.805% 4.478% 10.570%Total 50,169 45,918 4,251 226,844,060 86,307,048 140,537,012 3.903% 3.513% 8.116% 16.542% 10.521% 20.240%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting

Table A28b. Dichloromethane (Methylene chloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 3 2 1 0.484% 0.422% 0.685% 3,317 225 3,092 0.547% 0.097% 0.828%AL 4 3 1 1.515% 1.485% 1.613% 35,927 14,873 21,054 0.850% 1.324% 0.679%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.095% 0.099% 0.000% 32,291 32,291 0 0.524% 1.156% 0.000%CA 12 10 2 0.328% 0.318% 0.388% 351,170 155,838 195,332 0.980% 1.153% 0.875%CO 3 2 1 0.363% 0.331% 0.452% 2,137 337 1,800 0.043% 0.064% 0.040%CT 3 3 0 0.250% 0.258% 0.000% 550 550 0 0.020% 0.142% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 5 5 0 0.331% 0.336% 0.000% 70,510 70,510 0 0.403% 0.462% 0.000%GA 2 2 0 0.110% 0.117% 0.000% 1,585 1,585 0 0.021% 0.100% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.190% 0.196% 0.000% 3,129 3,129 0 0.123% 0.218% 0.000%ID 3 3 0 0.321% 0.342% 0.000% 2,240 2,240 0 0.205% 0.267% 0.000%IL 3 3 0 0.254% 0.278% 0.000% 512 512 0 0.006% 0.017% 0.000%IN 4 4 0 0.271% 0.280% 0.000% 650 650 0 0.013% 0.025% 0.000%KY 3 2 1 1.245% 2.174% 0.671% 17,990 1,542 16,448 0.391% 0.411% 0.389%MA 1 1 0 0.139% 0.167% 0.000% 8,019 8,019 0 0.094% 0.458% 0.000%MD 3 2 1 0.285% 0.203% 1.471% 1,710,307 307 1,710,000 34.047% 0.030% 42.770%ME 3 3 0 0.370% 0.396% 0.000% 675 675 0 0.093% 0.231% 0.000%MI 2 2 0 0.067% 0.069% 0.000% 82 82 0 0.001% 0.004% 0.000%MN 5 3 2 0.316% 0.193% 6.667% 49,713 13,145 36,568 1.167% 0.437% 2.926%MO 5 4 1 0.353% 0.299% 1.299% 17,228 9,695 7,533 0.573% 0.574% 0.573%MT 19 12 7 2.241% 1.523% 11.667% 15,995 12,077 3,918 2.110% 3.306% 0.998%NC 5 5 0 0.211% 0.224% 0.000% 518 518 0 0.007% 0.030% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 8 8 0 0.636% 0.657% 0.000% 971 971 0 0.102% 0.243% 0.000%NJ 4 3 1 0.286% 0.220% 2.703% 312,635 759 311,876 4.035% 0.028% 6.193%NM 5 5 0 0.688% 0.727% 0.000% 493 493 0 0.029% 0.034% 0.000%NV 1 1 0 0.296% 0.315% 0.000% 100 100 0 0.010% 0.035% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.162% 0.000%OH 5 5 0 0.257% 0.275% 0.000% 9,117 9,117 0 0.089% 0.291% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 1 1 0 0.690% 0.735% 0.000% 3,811 3,811 0 0.417% 2.191% 0.000%SC 1 1 0 0.122% 0.132% 0.000% 1,628 1,628 0 0.048% 0.222% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 0 1 0.285% 0.000% 0.529% 18,862 0 18,862 0.332% 0.000% 0.447%TX 10 9 1 0.202% 0.195% 0.292% 206,395 21,454 184,941 0.822% 0.231% 1.169%UT 3 3 0 0.600% 0.661% 0.000% 40,879 40,879 0 1.601% 2.406% 0.000%VA 1 1 0 0.063% 0.071% 0.000% 125 125 0 0.002% 0.020% 0.000%VT 1 1 0 0.166% 0.179% 0.000% 1,300 1,300 0 0.265% 0.573% 0.000%WI 7 7 0 0.392% 0.397% 0.000% 14,543 14,543 0 0.360% 0.619% 0.000%WV 1 0 1 0.248% 0.000% 0.625% 4,475 0 4,475 0.316% 0.000% 0.380%WY 6 5 1 1.974% 1.953% 2.083% 1,885 1,205 680 0.422% 0.932% 0.215%Total 147 125 22 0.293% 0.272% 0.518% 2,943,449 426,870 2,516,579 1.298% 0.495% 1.791%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L

Table A28c. Dichloromethane (Methylene chloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 18 6 12 2.903% 1.266% 8.219% 235,589 1,908 233,681 38.864% 0.820% 62.548%AL 11 6 5 4.167% 2.970% 8.065% 803,879 36,647 767,232 19.029% 3.263% 24.739%AR 1 1 0 0.220% 0.262% 0.000% 3,800 3,800 0 0.155% 0.417% 0.000%AZ 2 2 0 0.189% 0.198% 0.000% 32,321 32,321 0 0.524% 1.158% 0.000%CA 25 18 7 0.683% 0.573% 1.357% 1,642,625 353,377 1,289,248 4.584% 2.614% 5.778%CO 6 2 4 0.726% 0.331% 1.810% 38,493 337 38,156 0.770% 0.064% 0.854%CT 4 4 0 0.333% 0.345% 0.000% 750 750 0 0.028% 0.193% 0.000%DE 1 1 0 0.313% 0.316% 0.000% 105 105 0 0.015% 0.025% 0.000%FL 22 22 0 1.455% 1.480% 0.000% 802,550 802,550 0 4.586% 5.261% 0.000%GA 3 3 0 0.165% 0.176% 0.000% 2,835 2,835 0 0.038% 0.178% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 4 4 0 0.379% 0.391% 0.000% 3,349 3,349 0 0.132% 0.233% 0.000%ID 5 5 0 0.535% 0.569% 0.000% 37,960 37,960 0 3.471% 4.532% 0.000%IL 7 7 0 0.593% 0.648% 0.000% 7,912 7,912 0 0.087% 0.270% 0.000%IN 17 17 0 1.153% 1.189% 0.000% 71,958 71,958 0 1.471% 2.798% 0.000%KY 12 4 8 4.979% 4.348% 5.369% 261,300 1,792 259,508 5.677% 0.477% 6.139%MA 8 6 2 1.114% 1.000% 1.695% 29,876 10,045 19,831 0.349% 0.574% 0.291%MD 11 9 2 1.044% 0.913% 2.941% 1,711,368 965 1,710,403 34.068% 0.094% 42.780%ME 6 6 0 0.741% 0.793% 0.000% 1,146 1,146 0 0.157% 0.391% 0.000%MI 4 3 1 0.135% 0.103% 1.639% 221,976 32,833 189,143 3.104% 1.665% 3.652%MN 12 10 2 0.759% 0.644% 6.667% 145,163 108,595 36,568 3.407% 3.607% 2.926%MO 10 8 2 0.706% 0.597% 2.597% 30,132 11,945 18,187 1.003% 0.707% 1.384%MT 55 37 18 6.486% 4.695% 30.000% 151,509 20,412 131,097 19.989% 5.588% 33.386%NC 13 12 1 0.549% 0.539% 0.719% 11,178 7,418 3,760 0.160% 0.428% 0.071%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 13 12 1 1.033% 0.986% 2.439% 54,124 20,124 34,000 5.705% 5.044% 6.184%NJ 12 11 1 0.858% 0.808% 2.703% 362,012 50,136 311,876 4.672% 1.848% 6.193%NM 6 5 1 0.825% 0.727% 2.564% 1,043 493 550 0.061% 0.034% 0.206%NV 4 3 1 1.183% 0.946% 4.762% 56,797 297 56,500 5.834% 0.105% 8.190%NY 3 3 0 0.198% 0.234% 0.000% 1,930 1,930 0 0.039% 0.185% 0.000%OH 13 13 0 0.669% 0.715% 0.000% 10,192 10,192 0 0.100% 0.325% 0.000%OK 4 2 2 0.548% 0.386% 0.943% 23,881 610 23,271 0.765% 0.092% 0.946%OR 1 0 1 0.091% 0.000% 0.658% 1,075 0 1,075 0.037% 0.000% 0.045%RI 5 4 1 3.448% 2.941% 11.111% 72,563 4,300 68,263 7.940% 2.473% 9.225%SC 2 2 0 0.244% 0.264% 0.000% 2,353 2,353 0 0.070% 0.321% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 5 3 2 1.425% 1.852% 1.058% 101,448 82,521 18,927 1.784% 5.642% 0.448%TX 27 24 3 0.545% 0.521% 0.877% 967,793 71,607 896,186 3.854% 0.770% 5.667%UT 4 4 0 0.800% 0.881% 0.000% 146,879 146,879 0 5.753% 8.646% 0.000%VA 3 3 0 0.189% 0.212% 0.000% 1,840 1,840 0 0.035% 0.292% 0.000%VT 2 2 0 0.332% 0.357% 0.000% 1,384 1,384 0 0.282% 0.610% 0.000%WI 22 22 0 1.233% 1.247% 0.000% 46,597 46,597 0 1.154% 1.985% 0.000%WV 2 1 1 0.496% 0.412% 0.625% 4,524 49 4,475 0.319% 0.021% 0.380%WY 13 12 1 4.276% 4.688% 2.083% 4,830 4,150 680 1.083% 3.211% 0.215%Total 398 319 79 0.793% 0.695% 1.858% 8,109,039 1,996,422 6,112,617 3.575% 2.313% 4.349%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	


Table A28d. Dichloromethane (Methylene chloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 42 20 22 6.774% 4.219% 15.068% 260,328 14,440 245,888 42.945% 6.208% 65.815%AL 25 14 11 9.470% 6.931% 17.742% 1,411,820 76,732 1,335,088 33.420% 6.832% 43.049%AR 6 5 1 1.322% 1.309% 1.389% 27,602 11,555 16,047 1.125% 1.269% 1.040%AZ 8 7 1 0.756% 0.693% 2.083% 47,231 46,731 500 0.766% 1.674% 0.015%CA 74 50 24 2.022% 1.591% 4.651% 4,210,227 1,271,794 2,938,433 11.751% 9.408% 13.170%CO 16 7 9 1.937% 1.157% 4.072% 270,295 1,514 268,781 5.408% 0.286% 6.016%CT 8 7 1 0.667% 0.603% 2.564% 8,620 2,000 6,620 0.317% 0.515% 0.284%DE 3 2 1 0.940% 0.633% 33.333% 141,005 1,005 140,000 20.170% 0.241% 49.751%FL 40 40 0 2.646% 2.692% 0.000% 1,138,675 1,138,675 0 6.507% 7.465% 0.000%GA 13 12 1 0.714% 0.703% 0.862% 28,733 10,531 18,202 0.384% 0.661% 0.309%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 15 15 0 1.422% 1.468% 0.000% 13,760 13,760 0 0.541% 0.959% 0.000%ID 7 7 0 0.749% 0.797% 0.000% 38,403 38,403 0 3.511% 4.585% 0.000%IL 29 26 3 2.456% 2.405% 3.000% 173,752 103,673 70,079 1.903% 3.532% 1.131%IN 44 44 0 2.985% 3.077% 0.000% 86,889 86,889 0 1.776% 3.379% 0.000%KY 29 7 22 12.033% 7.609% 14.765% 638,410 43,217 595,193 13.871% 11.513% 14.081%MA 24 17 7 3.343% 2.833% 5.932% 234,708 67,265 167,443 2.743% 3.844% 2.460%MD 27 24 3 2.562% 2.434% 4.412% 1,843,181 28,211 1,814,970 36.692% 2.752% 45.396%ME 11 9 2 1.358% 1.189% 3.774% 40,351 2,101 38,250 5.540% 0.718% 8.782%MI 16 14 2 0.540% 0.482% 3.279% 227,828 35,766 192,062 3.186% 1.814% 3.708%MN 24 21 3 1.517% 1.353% 10.000% 234,705 129,691 105,014 5.509% 4.307% 8.403%MO 33 28 5 2.329% 2.090% 6.494% 73,066 30,633 42,433 2.432% 1.813% 3.228%MT 80 50 30 9.434% 6.345% 50.000% 382,101 104,882 277,219 50.412% 28.713% 70.599%NC 30 28 2 1.267% 1.257% 1.439% 463,653 28,346 435,307 6.625% 1.636% 8.268%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 1 1 0 0.130% 0.132% 0.000% 1,700 1,700 0 0.116% 0.248% 0.000%NH 19 17 2 1.510% 1.397% 4.878% 212,678 21,105 191,573 22.416% 5.290% 34.844%NJ 40 38 2 2.861% 2.792% 5.405% 1,064,460 76,330 988,130 13.738% 2.814% 19.622%NM 45 39 6 6.190% 5.669% 15.385% 249,916 119,003 130,913 14.710% 8.308% 49.114%NV 7 5 2 2.071% 1.577% 9.524% 60,930 591 60,339 6.258% 0.208% 8.746%NY 10 9 1 0.659% 0.701% 0.426% 6,740 5,813 927 0.138% 0.557% 0.024%OH 47 46 1 2.418% 2.529% 0.800% 24,452 23,452 1,000 0.239% 0.749% 0.014%OK 9 5 4 1.233% 0.965% 1.887% 30,000 4,142 25,858 0.960% 0.623% 1.052%OR 1 0 1 0.091% 0.000% 0.658% 1,075 0 1,075 0.037% 0.000% 0.045%RI 7 6 1 4.828% 4.412% 11.111% 76,193 7,930 68,263 8.337% 4.560% 9.225%SC 5 4 1 0.611% 0.528% 1.613% 8,841 2,553 6,288 0.263% 0.348% 0.240%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 10 5 5 2.849% 3.086% 2.646% 289,262 84,310 204,952 5.088% 5.765% 4.854%TX 80 69 11 1.616% 1.497% 3.216% 1,529,166 246,426 1,282,740 6.089% 2.651% 8.111%UT 5 5 0 1.000% 1.101% 0.000% 147,079 147,079 0 5.761% 8.657% 0.000%VA 6 6 0 0.378% 0.423% 0.000% 4,098 4,098 0 0.078% 0.651% 0.000%VT 4 4 0 0.663% 0.714% 0.000% 1,644 1,644 0 0.335% 0.724% 0.000%WI 56 54 2 3.139% 3.061% 10.000% 258,677 222,937 35,740 6.404% 9.496% 2.113%WV 4 1 3 0.993% 0.412% 1.875% 6,364 49 6,315 0.449% 0.021% 0.536%WY 16 15 1 5.263% 5.859% 2.083% 6,106 5,426 680 1.369% 4.199% 0.215%Total 976 783 193 1.945% 1.705% 4.540% 15,974,724 4,262,402 11,712,322 7.042% 4.939% 8.334%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	


Table A28e. Dichloromethane (Methylene chloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 79 41 38 12.742% 8.650% 26.027% 274,228 21,409 252,819 45.238% 9.205% 67.670%AL 32 19 13 12.121% 9.406% 20.968% 1,687,556 159,270 1,528,286 39.947% 14.180% 49.279%AR 9 8 1 1.982% 2.094% 1.389% 29,669 13,622 16,047 1.209% 1.496% 1.040%AZ 17 12 5 1.607% 1.188% 10.417% 793,079 104,115 688,964 12.869% 3.729% 20.440%CA 145 102 43 3.963% 3.245% 8.333% 10,589,878 2,364,657 8,225,221 29.556% 17.493% 36.864%CO 38 24 14 4.600% 3.967% 6.335% 327,054 5,969 321,085 6.544% 1.126% 7.187%CT 10 9 1 0.833% 0.775% 2.564% 20,925 14,305 6,620 0.769% 3.681% 0.284%DE 10 9 1 3.135% 2.848% 33.333% 158,347 18,347 140,000 22.651% 4.393% 49.751%FL 51 51 0 3.373% 3.432% 0.000% 1,270,475 1,270,475 0 7.260% 8.329% 0.000%GA 23 21 2 1.262% 1.231% 1.724% 54,700 33,827 20,873 0.731% 2.124% 0.354%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 18 18 0 1.706% 1.761% 0.000% 19,271 19,271 0 0.758% 1.343% 0.000%ID 9 9 0 0.963% 1.025% 0.000% 40,278 40,278 0 3.683% 4.809% 0.000%IL 74 65 9 6.266% 6.013% 9.000% 380,580 246,518 134,062 4.168% 8.398% 2.164%IN 64 62 2 4.342% 4.336% 4.545% 216,869 94,576 122,293 4.434% 3.678% 5.272%KY 41 10 31 17.012% 10.870% 20.805% 716,907 48,581 668,326 15.577% 12.942% 15.811%MA 40 30 10 5.571% 5.000% 8.475% 354,410 137,060 217,350 4.142% 7.832% 3.193%MD 41 35 6 3.890% 3.550% 8.824% 2,120,947 285,785 1,835,162 42.221% 27.873% 45.901%ME 13 10 3 1.605% 1.321% 5.660% 40,661 2,211 38,450 5.583% 0.755% 8.827%MI 34 30 4 1.147% 1.033% 6.557% 3,646,624 50,978 3,595,646 50.989% 2.585% 69.416%MN 32 28 4 2.023% 1.804% 13.333% 307,511 200,239 107,272 7.218% 6.651% 8.584%MO 58 51 7 4.093% 3.806% 9.091% 155,251 105,975 49,276 5.168% 6.272% 3.749%MT 101 64 37 11.910% 8.122% 61.667% 409,254 115,807 293,447 53.995% 31.704% 74.731%NC 41 39 2 1.732% 1.750% 1.439% 490,565 55,258 435,307 7.010% 3.189% 8.268%ND 4 3 1 1.914% 1.648% 3.704% 17,819 16,906 913 3.169% 6.575% 0.299%NE 2 2 0 0.259% 0.263% 0.000% 1,746 1,746 0 0.119% 0.255% 0.000%NH 36 33 3 2.862% 2.712% 7.317% 244,380 40,057 204,323 25.757% 10.040% 37.163%NJ 85 80 5 6.080% 5.878% 13.514% 1,534,780 233,775 1,301,005 19.807% 8.618% 25.834%NM 48 41 7 6.602% 5.959% 17.949% 256,103 122,453 133,650 15.074% 8.549% 50.141%NV 16 13 3 4.734% 4.101% 14.286% 92,629 32,090 60,539 9.514% 11.311% 8.775%NY 19 16 3 1.252% 1.247% 1.277% 13,584 9,457 4,127 0.278% 0.907% 0.107%OH 83 81 2 4.270% 4.453% 1.600% 151,031 70,781 80,250 1.477% 2.259% 1.131%OK 18 12 6 2.466% 2.317% 2.830% 92,384 63,357 29,027 2.958% 9.530% 1.181%OR 2 1 1 0.182% 0.106% 0.658% 1,215 140 1,075 0.041% 0.024% 0.045%RI 8 7 1 5.517% 5.147% 11.111% 76,485 8,222 68,263 8.369% 4.728% 9.225%SC 11 9 2 1.343% 1.189% 3.226% 13,093 5,305 7,788 0.390% 0.724% 0.297%SD 1 1 0 0.408% 0.429% 0.000% 113 113 0 0.042% 0.058% 0.000%TN 12 5 7 3.419% 3.086% 3.704% 296,683 84,310 212,373 5.218% 5.765% 5.029%TX 149 121 28 3.009% 2.625% 8.187% 4,663,260 366,008 4,297,252 18.570% 3.937% 27.172%UT 9 7 2 1.800% 1.542% 4.348% 539,819 151,779 388,040 21.143% 8.934% 45.421%VA 7 7 0 0.441% 0.494% 0.000% 4,388 4,388 0 0.083% 0.697% 0.000%VT 8 7 1 1.327% 1.250% 2.326% 2,268 2,018 250 0.462% 0.889% 0.095%WI 108 106 2 6.054% 6.009% 10.000% 397,109 361,369 35,740 9.831% 15.392% 2.113%WV 6 3 3 1.489% 1.235% 1.875% 8,899 2,584 6,315 0.628% 1.087% 0.536%WY 20 17 3 6.579% 6.641% 6.250% 16,447 5,787 10,660 3.686% 4.478% 3.363%Total 1,632 1,319 313 3.253% 2.873% 7.363% 32,529,274 6,991,178 25,538,096 14.340% 8.100% 18.172%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L

Table A28f. Dichloromethane (Methylene chloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 70 μg/L 30,172 0 0.000% 67,200,878 0 0.000%'	
 30,172 1 0.003% 67,200,878 1,810 0.003%

	
 30,172 2 0.007% 67,200,878 *+' 0.003%

> 70 μg/L * 1 0.033% ** 13,933 0.012%

'	
 * 1 0.033% ** 13,933 0.012%

	
 * 1 0.033% ** 13,933 0.012%

> 70 μg/L 33,187 1 0.003% +*'*+ 13,933 0.007%

'	
 33,187 2 0.006% +*'*+ *' 0.008%

	
 33,187 3 0.009% +*'*+ *+ 0.008%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water

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Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 76 ' ' ='| '| 0.000% 0.17 0.17 0.26 0.26 0.36 0.36 0.36 0.36AL 629 '' 187 =| 0.226% 0.000%        AR *++ * 231 0.000% 0.000% 0.000%AZ 6,803 *+ *' '| '| '| 0.1 0.1 0.1  0.1  ' 0.37 ' ' '= 'CA '*} +*'}} }*'' | 0.012% 0.163% 0.009 0.68 0.009 0.2 0.68 0.2 0.68 0.68 3.31 6.3 0.68 6.3CO *= 1,862 677 +| 0.161% '+| ' '  ' =  0.6 0.6  0.6 0.6 CT *=+ 1,012 +} '+| 0.000% =| 0.19 0.19 0.22 0.22 0.22 0.22 0.22 0.22DE 826 788 38 0.121% 0.000% 2.632%        FL *' *'' 67 ==| 0.981% '=| 0.06 0.06 0.16 0.8 0.98 0.16 1 1 0.16 70 70 0.16GA *' * 78 '=| =| 1.282%   0.69 0.63  0.69 0.69 0.66 0.69 0.69 0.66 0.69HIIA *' *} 130 0.229% 0.186% 0.769% 0.1 0.2 0.1   0.1 0.27 0.27 0.1 0.27 0.27 0.1ID 2,079 1,799 280 '+| }| 0.000% 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18IL '*} *'+ =+ 0.098% 0.086% 0.167% 0.1 0.1 1.1 +  1.1 2.2 2.2 1.1 2.2 2.2 1.1IN *' 2,309 166 0.283% '| }'|   0.2 0.3   0.8  0.8 0.8  0.8KY * ' 1,318 1.197% 0.000% =| 0.1 0.1 0.3 0.3 0.7 0.7 230 230< 2,981 2,188 793 | 0.320% 0.000% ' ' 0.17 0.17 1.1 1.1 1.1 1.1@ * 1,699 803 3.038% '| '=| 0.1 0.1 0.12 0.26 ' 0.27 0.78 ' 1.06  1.21 ~ 378 317 61 0.000% 0.000% 0.000% }*+ 6,292 293 0.000% 0.000% 0.000% '*} '*'= 132 0.303% 0.311% 0.000%     ' '   *+ '*=+ 819 '| 0.000% ''| ' ' 1.63 1.63 2.12 2.12 2.12 2.12: 3,190 2,908 282 0.063% '| | ' ' = } ' = = ' = = ' =NC 13,960 12,727 1,233 | | +}| 0.1 0.1 0.1 0.3  ' 1.2 1.3 ' 7.9 7.9 1.7ND '' ' 63 0.000% 0.000% 0.000%NE 2,220 *' 77 0.000% 0.000% 0.000%NH '*= *+' 319 '| 0.026% 0.000% 19 19 19 19 19 19 19 19NJ 162 '' 18 0.000% 0.000% 0.000% '* '* ' 0.138% '}| 0.000% 0.28 0.28 } } = = = =NV *} 1,161 ' 0.190% 0.172% '| 0.29 0.39 0.29 0.39 = 0.29 10 10 0.29 10 10 0.29NY 2,891 2,172 719 0.173% 0.092% '| 0.3 1.7 0.3 0.7  0.69 2.6 2.6 0.7 2.6 2.6 0.7OH + 387 =' 0.688% 0.000% 2.062% 0.1 0.1 = =    OKOR 2,082 *== '+ 0.000% 0.000% 0.000%RI ' '=+ ' 0.000% 0.000% 0.000%SC 3,307 2,896 ' 0.393% 0.069% 2.676% 0.11 0.11 0.22 0.38  ' 0.63 0.2 0.63 1.2 0.2 1.2SD =} +'+ 117 0.207% 0.118% +| 0.6 2.66 0.6 1.63 2.66 0.6 2.66 2.66 0.6 2.66 2.66 0.6TN 71 12 = 0.000% 0.000% 0.000%TX *' *' 831 0.000% 0.000% 0.000%UT *=' *=} 1,188 0.000% 0.000% 0.000%VA '' '+ =' 0.000% 0.000% 0.000%VT 1,299 * =' 0.231% 0.181% |   1 1  1 1 1 1 1 1 1WI *}' 3,072 92 +| 0.130% 1.087% 0.1 0.1 0.2 0.2 0.2 0.2 ' ' 0.2 ' ' 0.2WV }'+ ' 308 2.006% }'| 1.299% 0.02 0.02 0.02 0.02 0.02 0.16 0.3 0.1   0.1 WY * =' ' 0.000% 0.000% 0.000%Total '*+ 101,329 *=} '=| 0.283% }'| 0.009 0.02 0.009 0.3 0.3 0.29  2 1.1 230 70 230:;<=*'?@Q!
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Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

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AK 20   }*' +* *' | 6.667% 0.000% +=| }'| 0.000%AL +' 132  2,871,122 }*=' *'*+ '| +| 0.000% '| 1.917% 0.000%AR '' 382 72 *'*'+ 910,322 *'*} 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 918 870 '+ }*'*' *}'*'} **= 2.070% 1.609% '| 38.197% 3.302% }++}|CA 1,609 1,283 326 *}+*'' **'= 21,361,927 '| 0.078% +'| '=}| '| 2.096%CO 816 = 219 '*=='* *' '*'}}*== 0.368% | '| 0.039% 0.328% |CT } 617 38 *=* }*' 2,333,887 0.611% 0.000% }| '| 0.000% =|DE '  3 }'*} '* +*' ='| 0.000% 33.333% }+'| 0.000% '=|FL 1,320 1,298 22 }*==*}' '**}}= *'* 0.833% 0.770% ''| '}| 18.239% 10.799%GA 297 283 ' ==*' * 692,022 }+'| '| '| +| '+'| 26.011%HIIA * 1,022 33 *'*}' *''* 1,108,626 0.379% ='| 3.030% 0.231% 0.077% '|ID 870 813  *}'*+} 808,630 }*=} | 0.123% 0.000% | 0.006% 0.000%IL 1,368 *}' ' =*+*' *=+*+ 6,200,397 0.292% 0.237% 0.962% 0.071% 0.138% 0.039%IN *'} 1,362 '' '*+*= ** 2,319,736 +'| 0.073% 6.818% '}| 0.001% '=+|KY ' 92 '= '*=}*+ 369,299 '**= 6.639% 0.000% 10.738% ''| 0.000% ''+|< }' + 117 +*=*= ** 6,802,382 0.930% 1.136% 0.000% =+'| '=| 0.000%@ 862 =' 68 '*=}* =*+=' 3,998,107 6.381% '+}| | 80.103% 19.868% 93.781%~ 216 190 26 '=* }*+'+ '*+= 0.000% 0.000% 0.000% 0.000% 0.000% 0.000% 2,919 *++ 61 *'*= *''* *=*+} 0.000% 0.000% 0.000% 0.000% 0.000% 0.000% 1,288 *= 29 *=*}' *}+'* *'=*}' 0.233% 0.238% 0.000% 0.036% | 0.000% *' 1,398 77 3,281,888 ** *+* 0.136% 0.000% =| 0.183% 0.000% 0.380%: +'} 786 60 *+ }*' 392,669 0.236% 0.127% 1.667% 0.307% | 0.102%NC *} 2,228 137 }*++* ** **}} ''+| ==| '=| '=| '=| +|ND 209 182 27 =*=+ *= * 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 739 728 11 *''*} 678,193 }*'+ 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 ' ='*' =*= '=*== 0.081% +'| 0.000% 0.003% 0.006% 0.000%NJ 127 116 11 1,969,193 '*= 1,627,220 0.000% 0.000% 0.000% 0.000% 0.000% 0.000% 692 }  *}}*+= *=*=' 261,098 ''| '| 0.000% | }| 0.000%NV 288 267 21 =}*}+ 270,677 689,891 '| '=| '}| 26.096% 1.717% }}|NY *'+ 1,117 231 '*=*}}} 982,389 *='* 0.223% 0.090% 0.866% | 0.172% 0.301%OH 273 =' 79 }**'+ '+'* }**= 0.366% 0.000% 1.266% 0.721% 0.000% 0.779%OKOR *=' =''  2,939,761 * *}'* 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 89 80 9 =*}= 160,717 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC +  60 *''+*=' 820,701 2,627,693 }}| 0.276% 18.333% 8.626% 0.618% 11.127%SD 260 239 21 }* 262,981 =* 0.769% '+| '}| 20.700% | }|TN 16  11 **' ''*=} 1,067,080 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX +} 702 ' +**' '**}++ '*}+}*= 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT '} 389 37 **} *}}*'+ 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 173 63 110 2,380,983 }*=' *'*= 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT '' ' 33 '*''= +*+ *}' 0.682% '=| 3.030% 3.739% 0.280% 6.236%WI *'} 1,386 20 3,883,613 2,191,869 *}=*'' +'| 0.216% | '}| 0.380% 0.073%WV ' 197 ' *}*}' 206,326 *}*'+ 3.216% '}=| 1.379% =}| 0.961% |WY ' } '+ ''}* 129,229 }*='+ 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 33,187 30,172 * +*'*+ 67,200,878 ** 0.901% 0.669% 3.217% +'| | 10.613%

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#$

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Reporting

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with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

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Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 '| 0.000% 0.671% 13,933 0 13,933 0.303% 0.000% 0.330%< 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%@ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%~ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%: 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 0 1 0.003% 0.000% 0.033% 13,933 0 13,933 0.007% 0.000% 0.012%

j!`j
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with At Least One Detection 

> 70 μg/L State

Number of Systems 

with At Least One Detection 

> 70 μg/L

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> 70 μg/L

j
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with At Least One Detection 

> 70 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

:;<=*'?@Q!
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Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.076% 0.077% 0.000% 1,810 1,810 0 0.011% 0.012% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 '| 0.000% 0.671% 13,933 0 13,933 0.303% 0.000% 0.330%< 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%@ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%~ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%: 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 1 1 0.006% 0.003% 0.033% *' 1,810 13,933 0.008% 0.003% 0.012%

j!`j
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'	
 State

Number of Systems 

with At Least One Detection 

'	


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'	


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'	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.076% 0.077% 0.000% 1,810 1,810 0 0.011% 0.012% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 '| 0.000% 0.671% 13,933 0 13,933 0.303% 0.000% 0.330%< 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%@ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%~ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 1 1 0 0.078% 0.079% 0.000%   0 0.001% 0.001% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%: 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 3 2 1 0.009% 0.007% 0.033% *+ *+' 13,933 0.008% 0.003% 0.012%

j!`j
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 State

Number of Systems 

with At Least One Detection 

	


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:;<=*'?@Q!
Q\"^_!"`Qjq$<"{Q!Q`!!!"
#$
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A30. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 46,180 8 0.017% 86,395,709 16,691 0.019%

	
 46,180 33 0.071% 86,395,709 43,469 0.050%

	
 46,180 84 0.182% 86,395,709 464,180 0.537%

> 0.5 μg/L 46,180 150 0.325% 86,395,709 666,040 0.771%

> 5 μg/L 4,257 2 0.047% 140,516,425 334,996 0.238%

	
 4,257 6 0.141% 140,516,425 1,094,057 0.779%

	
 4,257 14 0.329% 140,516,425 7,662,775 5.453%

> 0.5 μg/L 4,257 15 0.352% 140,516,425 8,053,925 5.732%

> 5 μg/L 50,437 10 0.020% 226,912,134 351,687 0.155%

	
 50,437 39 0.077% 226,912,134 1,137,526 0.501%

	
 50,437 98 0.194% 226,912,134 8,126,955 3.582%

> 0.5 μg/L 50,437 165 0.327% 226,912,134 8,719,965 3.843%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A30a. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,108 1,971 1,137 0.064% 0.101% 0.000% 0.68 0.68 2.69 2.69 4.7 4.7 4.7 4.7AL 821 597 224 0.122% 0.168% 0.000% 0.51 0.51 0.51 0.51 0.51 0.51 0.51 0.51AR 3,969 3,237 732 0.126% 0.154% 0.000% 0.11 0.11 0.16 0.16 0.22 0.22 0.22 0.22AZ 11,702 9,533 2,169 0.043% 0.021% 0.138% 0.5 0.6 0.5 0.5 1.4 0.5 2.2 2.2 0.5 2.2 2.2 0.5CA 85,571 45,296 40,275 0.293% 0.068% 0.546% 0.25 0.25 0.5 1.1 0.55 1.2 2.5 1 2.55 26.2 2.8 26.2CO 2,871 2,131 740 0.000% 0.000% 0.000%CT 6,938 6,047 891 1.009% 1.141% 0.112% 0.5 0.5 0.8 3.1 3.1 0.8 6.45 6.5 0.8 11.3 11.3 0.8DE 1,048 1,018 30 0.000% 0.000% 0.000%FL 4,147 4,079 68 0.241% 0.245% 0.000% 0.09 0.09 0.275 0.275 3.95 3.95 4 4GA 7,176 6,349 827 0.223% 0.252% 0.000% 0.5 0.5 1.1 1.1 1.3 1.3 1.5 1.5HI 1,790 1,687 103 0.056% 0.059% 0.000% 1 1 1 1 1 1 1 1IA 1,776 1,651 125 0.169% 0.182% 0.000% 0.6 0.6 0.6 0.6 1.4 1.4 1.4 1.4ID 3,765 3,304 461 0.000% 0.000% 0.000%IL 6,996 6,436 560 0.057% 0.062% 0.000% 0.63 0.63 0.725 0.725 2.91 2.91 2.91 2.91IN 4,622 4,312 310 0.130% 0.139% 0.000% 0.5 0.5 0.79 0.79 1.6 1.6 1.6 1.6KY 3,313 1,126 2,187 0.272% 0.000% 0.412% 0.005 0.005 0.5 0.5 1 1 1 1MA 16,249 12,259 3,990 0.018% 0.008% 0.050% 0.8 1.83 0.8 1 1.83 0.9 1.83 1.83 1 1.83 1.83 1MD 6,772 5,511 1,261 0.340% 0.417% 0.000% 0.5 0.5 1.1 1.1 2 2 5.2 5.2ME 3,698 3,383 315 0.027% 0.030% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5MI 10,753 9,743 1,010 0.186% 0.205% 0.000% 0.4 0.4 0.65 0.65 2.35 2.35 4.4 4.4MN 8,582 7,333 1,249 0.338% 0.395% 0.000% 0.2 0.2 0.4 0.4 1.3 1.3 4.7 4.7MO 7,544 6,695 849 0.013% 0.015% 0.000% 2.66 2.66 2.66 2.66 2.66 2.66 2.66 2.66MT 4,491 3,952 539 0.045% 0.051% 0.000% 0.58 0.58 0.71 0.71 0.84 0.84 0.84 0.84NC 19,065 17,486 1,579 1.317% 1.435% 0.000% 0.5 0.5 1 1 2.4 2.4 9.5 9.5ND 552 417 135 0.000% 0.000% 0.000%NE 6,844 6,265 579 0.161% 0.176% 0.000% 0.6 0.6 0.99 0.99 2.43 2.43 3.3 3.3NH 9,581 9,103 478 0.417% 0.439% 0.000% 0.32 0.32 1.7 1.7 2.4 2.4 3 3NJ 20,355 18,567 1,788 0.265% 0.237% 0.559% 0.1 0.1 0.1 0.505 0.5 0.65 2.4 2.9 1.55 3.9 3.9 1.8NM 6,576 6,100 476 0.015% 0.016% 0.000% 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2NV 3,209 2,577 632 0.000% 0.000% 0.000%NY 7,078 5,407 1,671 0.113% 0.111% 0.120% 0.5 0.5 0.5 0.5 0.8 0.5 10.6 10.6 0.5 10.6 10.6 0.5OH 8,852 7,689 1,163 0.045% 0.052% 0.000% 0.11 0.11 1.7 1.7 11 11 11 11OK 5,636 4,201 1,435 0.071% 0.071% 0.070% 0.5 0.5 0.5 0.55 0.6 0.5 5.7 5.7 0.5 5.7 5.7 0.5OR 2,324 1,682 642 0.086% 0.119% 0.000% 0.7 0.7 1.35 1.35 2 2 2 2RI 1,959 1,591 368 0.000% 0.000% 0.000%SC 4,342 3,803 539 0.299% 0.289% 0.371% 0.52 0.52 10 1.41 0.97 10 10 3.22 10 10 3.29 10SD 889 855 34 0.337% 0.351% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5TN 2,936 1,165 1,771 0.034% 0.086% 0.000% 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7TX 34,143 27,039 7,104 0.012% 0.015% 0.000% 0.5 0.5 0.9 0.9 1.9 1.9 1.9 1.9UT 8,993 7,562 1,431 0.000% 0.000% 0.000%VA 4,932 4,058 874 0.081% 0.099% 0.000% 1 1 1.4 1.4 1.7 1.7 1.7 1.7VT 4,350 3,956 394 0.046% 0.051% 0.000% 0.2 0.2 0.6 0.6 1 1 1 1WI 11,290 11,165 125 0.390% 0.394% 0.000% 0.01 0.01 0.465 0.465 1.3 1.3 3.3 3.3WV 1,142 444 698 1.226% 2.477% 0.430% 0.11 0.11 0.5 0.5 0.5 0.5 0.5 0.5 1 1 0.5 1WY 1,659 1,156 503 0.000% 0.000% 0.000%Total 374,409 289,938 84,471 0.246% 0.231% 0.300% 0.005 0.01 0.005 1 0.9 1.1 2.9 3.1 2.5 26.2 11.3 26.2

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A30b. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.323% 0.422% 0.000% 0.040% 0.104% 0.000%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.380% 0.495% 0.000% 0.635% 2.384% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.881% 1.047% 0.000% 0.214% 0.577% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.189% 0.099% 2.083% 4.865% 0.001% 8.901%CA 3,649 3,132 517 35,802,685 13,514,997 22,287,688 0.603% 0.447% 1.547% 19.154% 3.423% 28.693%CO 826 605 221 4,997,841 530,207 4,467,634 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.414% 0.342% 2.564% 14.874% 3.574% 16.759%DE 318 315 3 698,987 417,587 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,509 1,483 26 17,495,514 15,249,472 2,246,042 0.398% 0.405% 0.000% 2.766% 3.174% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.329% 0.352% 0.000% 0.055% 0.260% 0.000%HI 106 94 12 1,293,745 1,239,117 54,628 0.943% 1.064% 0.000% 0.050% 0.052% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.284% 0.293% 0.000% 0.037% 0.065% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.140% 0.151% 0.000% 0.015% 0.046% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.271% 0.280% 0.000% 0.018% 0.034% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 2.490% 0.000% 4.027% 9.098% 0.000% 9.906%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.279% 0.167% 0.847% 0.208% 0.009% 0.260%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.759% 0.811% 0.000% 0.795% 3.896% 0.000%ME 810 757 53 728,347 292,773 435,574 0.123% 0.132% 0.000% 0.030% 0.073% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.437% 0.447% 0.000% 0.040% 0.146% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 1.264% 1.289% 0.000% 3.340% 4.727% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.071% 0.075% 0.000% 0.109% 0.194% 0.000%MT 848 788 60 757,949 365,280 392,669 0.236% 0.254% 0.000% 0.014% 0.029% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 1.732% 1.840% 0.000% 0.369% 1.492% 0.000%ND 210 183 27 562,397 257,172 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.389% 0.395% 0.000% 0.183% 0.391% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 0.238% 0.247% 0.000% 0.036% 0.087% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 1.502% 1.396% 5.405% 13.881% 5.226% 18.543%NM 726 687 39 1,698,755 1,432,207 266,548 0.138% 0.146% 0.000% 0.010% 0.011% 0.000%NV 338 317 21 973,592 283,701 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,525 1,289 236 4,895,654 1,045,052 3,850,602 0.459% 0.388% 0.847% 0.098% 0.429% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.154% 0.165% 0.000% 0.045% 0.146% 0.000%OK 730 518 212 3,123,687 664,833 2,458,854 0.548% 0.579% 0.472% 0.051% 0.079% 0.044%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.182% 0.212% 0.000% 0.010% 0.052% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.366% 0.264% 1.613% 7.929% 0.062% 10.126%SD 245 233 12 266,416 194,218 72,198 0.408% 0.429% 0.000% 2.064% 2.832% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.285% 0.617% 0.000% 0.093% 0.362% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.020% 0.022% 0.000% 0.002% 0.005% 0.000%UT 500 454 46 2,553,197 1,698,877 854,320 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 0.063% 0.070% 0.000% 0.001% 0.010% 0.000%VT 603 560 43 491,035 227,067 263,968 0.332% 0.357% 0.000% 0.967% 2.090% 0.000%WI 1,783 1,763 20 4,039,401 2,347,657 1,691,744 1.290% 1.305% 0.000% 0.760% 1.308% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.193% 1.018% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,437 46,180 4,257 226,912,134 86,395,709 140,516,425 0.480% 0.468% 0.611% 4.483% 1.644% 6.229%

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting Percent of Systems with At Least One Detection Total Population Served by Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A30c. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 0 1 0.027% 0.000% 0.193% 69,300 0 69,300 0.194% 0.000% 0.311%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.083% 0.086% 0.000% 13,707 13,707 0 0.503% 3.520% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 1 0 0.095% 0.101% 0.000% 45 45 0 0.001% 0.004% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 3 0 0.127% 0.135% 0.000% 832 832 0 0.012% 0.048% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.161% 0.000%OH 1 1 0 0.051% 0.055% 0.000% 342 342 0 0.003% 0.011% 0.000%OK 1 1 0 0.137% 0.193% 0.000% 80 80 0 0.003% 0.012% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 0 1 0.122% 0.000% 1.613% 265,696 0 265,696 7.915% 0.000% 10.126%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 10 8 2 0.020% 0.017% 0.047% 351,687 16,691 334,996 0.155% 0.019% 0.238%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A30d. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.161% 0.211% 0.000% 158 158 0 0.026% 0.068% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 6 1 5 0.164% 0.032% 0.967% 828,611 250 828,361 2.314% 0.002% 3.717%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 2 2 0 0.166% 0.171% 0.000% 13,802 13,802 0 0.507% 3.544% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.066% 0.067% 0.000% 16,800 16,800 0 0.096% 0.110% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 980 980 0 0.011% 0.032% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 1 0 0.095% 0.101% 0.000% 45 45 0 0.001% 0.004% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 2 2 0 0.067% 0.069% 0.000% 530 530 0 0.007% 0.027% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 25 25 0 0.001% 0.001% 0.000%MO 1 1 0 0.071% 0.075% 0.000% 3,273 3,273 0 0.109% 0.194% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 9 9 0 0.380% 0.404% 0.000% 2,460 2,460 0 0.035% 0.142% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 1 1 0 0.130% 0.132% 0.000% 1,066 1,066 0 0.073% 0.155% 0.000%NH 1 1 0 0.079% 0.082% 0.000% 48 48 0 0.005% 0.012% 0.000%NJ 5 5 0 0.358% 0.367% 0.000% 1,032 1,032 0 0.013% 0.038% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.161% 0.000%OH 1 1 0 0.051% 0.055% 0.000% 342 342 0 0.003% 0.011% 0.000%OK 1 1 0 0.137% 0.193% 0.000% 80 80 0 0.003% 0.012% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 2 1 1 0.244% 0.132% 1.613% 265,738 42 265,696 7.916% 0.006% 10.126%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.112% 0.113% 0.000% 851 851 0 0.021% 0.036% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 39 33 6 0.077% 0.071% 0.141% 1,137,526 43,469 1,094,057 0.501% 0.050% 0.779%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A30e. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.161% 0.211% 0.000% 158 158 0 0.026% 0.068% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 30 30 0 0.000% 0.001% 0.000%CA 13 5 8 0.356% 0.160% 1.547% 6,742,015 347,020 6,394,995 18.831% 2.568% 28.693%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 3 3 0 0.249% 0.257% 0.000% 13,890 13,890 0 0.510% 3.567% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 2 2 0 0.133% 0.135% 0.000% 37,296 37,296 0 0.213% 0.245% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 1,000 1,000 0 0.013% 0.063% 0.000%HI 1 1 0 0.943% 1.064% 0.000% 650 650 0 0.050% 0.052% 0.000%IA 1 1 0 0.095% 0.098% 0.000% 739 739 0 0.029% 0.052% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 980 980 0 0.011% 0.032% 0.000%IN 1 1 0 0.068% 0.070% 0.000% 258 258 0 0.005% 0.010% 0.000%KY 1 0 1 0.415% 0.000% 0.671% 48,800 0 48,800 1.060% 0.000% 1.154%MA 2 1 1 0.279% 0.167% 0.847% 17,842 152 17,690 0.208% 0.009% 0.260%MD 3 3 0 0.285% 0.304% 0.000% 25,345 25,345 0 0.505% 2.472% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 4 4 0 0.135% 0.137% 0.000% 1,280 1,280 0 0.018% 0.065% 0.000%MN 6 6 0 0.379% 0.387% 0.000% 1,209 1,209 0 0.028% 0.040% 0.000%MO 1 1 0 0.071% 0.075% 0.000% 3,273 3,273 0 0.109% 0.194% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 24 24 0 1.014% 1.077% 0.000% 17,723 17,723 0 0.253% 1.023% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 0.259% 0.263% 0.000% 2,647 2,647 0 0.181% 0.386% 0.000%NH 2 2 0 0.159% 0.164% 0.000% 96 96 0 0.010% 0.024% 0.000%NJ 10 8 2 0.715% 0.588% 5.405% 935,815 2,021 933,794 12.077% 0.075% 18.543%NM 1 1 0 0.138% 0.146% 0.000% 163 163 0 0.010% 0.011% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 2 2 0 0.131% 0.155% 0.000% 1,785 1,785 0 0.036% 0.171% 0.000%OH 1 1 0 0.051% 0.055% 0.000% 342 342 0 0.003% 0.011% 0.000%OK 1 1 0 0.137% 0.193% 0.000% 80 80 0 0.003% 0.012% 0.000%OR 1 1 0 0.091% 0.106% 0.000% 31 31 0 0.001% 0.005% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 2 1 1 0.244% 0.132% 1.613% 265,738 42 265,696 7.916% 0.006% 10.126%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 474 474 0 0.002% 0.005% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.070% 0.000% 60 60 0 0.001% 0.010% 0.000%VT 1 1 0 0.166% 0.179% 0.000% 90 90 0 0.018% 0.040% 0.000%WI 6 6 0 0.337% 0.340% 0.000% 5,346 5,346 0 0.132% 0.228% 0.000%WV 1 0 1 0.248% 0.000% 0.625% 1,800 0 1,800 0.127% 0.000% 0.153%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 98 84 14 0.194% 0.182% 0.329% 8,126,955 464,180 7,662,775 3.582% 0.537% 5.453%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A30f. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 2 2 0 0.323% 0.422% 0.000% 241 241 0 0.040% 0.104% 0.000%AL 1 1 0 0.380% 0.495% 0.000% 26,778 26,778 0 0.635% 2.384% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 30 30 0 0.000% 0.001% 0.000%CA 21 13 8 0.576% 0.415% 1.547% 6,857,618 462,623 6,394,995 19.154% 3.423% 28.693%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 5 4 1 0.414% 0.342% 2.564% 405,070 13,920 391,150 14.874% 3.574% 16.759%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 2 2 0 0.133% 0.135% 0.000% 37,296 37,296 0 0.213% 0.245% 0.000%GA 5 5 0 0.274% 0.293% 0.000% 4,094 4,094 0 0.055% 0.257% 0.000%HI 1 1 0 0.943% 1.064% 0.000% 650 650 0 0.050% 0.052% 0.000%IA 3 3 0 0.284% 0.293% 0.000% 934 934 0 0.037% 0.065% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 2 2 0 0.140% 0.151% 0.000% 1,380 1,380 0 0.015% 0.046% 0.000%IN 3 3 0 0.204% 0.210% 0.000% 347 347 0 0.007% 0.013% 0.000%KY 1 0 1 0.415% 0.000% 0.671% 48,800 0 48,800 1.060% 0.000% 1.154%MA 2 1 1 0.279% 0.167% 0.847% 17,842 152 17,690 0.208% 0.009% 0.260%MD 7 7 0 0.664% 0.710% 0.000% 39,878 39,878 0 0.794% 3.889% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 11 11 0 0.370% 0.378% 0.000% 2,255 2,255 0 0.032% 0.114% 0.000%MN 9 9 0 0.569% 0.580% 0.000% 20,118 20,118 0 0.472% 0.668% 0.000%MO 1 1 0 0.071% 0.075% 0.000% 3,273 3,273 0 0.109% 0.194% 0.000%MT 2 2 0 0.236% 0.254% 0.000% 106 106 0 0.014% 0.029% 0.000%NC 41 41 0 1.732% 1.840% 0.000% 25,849 25,849 0 0.369% 1.492% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 3 3 0 0.389% 0.395% 0.000% 2,681 2,681 0 0.183% 0.391% 0.000%NH 2 2 0 0.159% 0.164% 0.000% 96 96 0 0.010% 0.024% 0.000%NJ 13 11 2 0.930% 0.808% 5.405% 942,132 8,338 933,794 12.159% 0.307% 18.543%NM 1 1 0 0.138% 0.146% 0.000% 163 163 0 0.010% 0.011% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 2 2 0 0.131% 0.155% 0.000% 1,785 1,785 0 0.036% 0.171% 0.000%OH 1 1 0 0.051% 0.055% 0.000% 342 342 0 0.003% 0.011% 0.000%OK 2 2 0 0.274% 0.386% 0.000% 212 212 0 0.007% 0.032% 0.000%OR 2 2 0 0.182% 0.212% 0.000% 301 301 0 0.010% 0.052% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 3 2 1 0.366% 0.264% 1.613% 266,150 454 265,696 7.929% 0.062% 10.126%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 1 0 0.285% 0.617% 0.000% 5,294 5,294 0 0.093% 0.362% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 474 474 0 0.002% 0.005% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.070% 0.000% 60 60 0 0.001% 0.010% 0.000%VT 1 1 0 0.166% 0.179% 0.000% 90 90 0 0.018% 0.040% 0.000%WI 11 11 0 0.617% 0.624% 0.000% 5,826 5,826 0 0.144% 0.248% 0.000%WV 1 0 1 0.248% 0.000% 0.625% 1,800 0 1,800 0.127% 0.000% 0.153%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 165 150 15 0.327% 0.325% 0.352% 8,719,965 666,040 8,053,925 3.843% 0.771% 5.732%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A31. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 7 μg/L 29,785 5 0.017% 66,425,963 26,212 0.039%

	
 29,785 6 0.020% 66,425,963 26,292 0.040%

> 7 μg/L 2,928 0 0.000% 116,493,427 0 0.000%

	
 2,928 0 0.000% 116,493,427 0 0.000%

> 7 μg/L 32,713 5 0.015% 182,919,390 26,212 0.014%

	
 32,713 6 0.018% 182,919,390 26,292 0.014%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A31a. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 73 39 34 0.000% 0.000% 0.000%AL 560 396 164 0.536% 0.505% 0.610% 0.7 0.7 1.09 1.09 1.345 1.09 1.99 1.99 1.09 1.99 1.99 1.09AR 1,588 1,357 231 0.000% 0.000% 0.000%AZ 6,826 5,406 1,420 0.308% 0.314% 0.282% 0.2 0.2 0.2 0.23 0.23 0.25 0.43 0.99 0.3 1.3 1.3 0.3CA 13,983 8,183 5,800 0.007% 0.012% 0.000% 2 2 2 2 2 2 2 2CO 2,527 1,849 678 0.000% 0.000% 0.000%CT 1,590 1,273 317 0.000% 0.000% 0.000%DE 826 788 38 1.695% 1.777% 0.000% 0.08 0.08 3.805 3.805 12.3 12.3 14.7 14.7FL 2,390 2,323 67 0.544% 0.560% 0.000% 0.05 0.05 0.1 0.1 0.1 0.1 1.3 1.3GA 1,433 1,355 78 0.000% 0.000% 0.000%HIIA 1,732 1,602 130 0.000% 0.000% 0.000%ID 2,074 1,793 281 0.000% 0.000% 0.000%IL 3,182 2,648 534 0.000% 0.000% 0.000%IN 2,289 2,123 166 0.087% 0.094% 0.000% 0.1 0.1 0.545 0.545 0.99 0.99 0.99 0.99KY 1,756 444 1,312 0.399% 0.000% 0.534% 0.07 0.07 0.2 0.2 3 3 3 3MA 2,962 2,170 792 0.338% 0.369% 0.253% 0.1 0.1 0.1 0.5 0.85 0.1 1.5 2 0.1 2 2 0.1MD 2,494 1,700 794 0.882% 0.882% 0.882% 0.07 0.07 0.14 0.16 0.14 0.24 0.71 1.1 0.71 1.19 1.19 0.71ME 378 317 61 0.000% 0.000% 0.000%MI 6,582 6,289 293 0.046% 0.048% 0.000% 0.13 0.13 0.3 0.3 0.4 0.4 0.4 0.4MN 4,627 4,495 132 0.000% 0.000% 0.000%MO 5,803 4,984 819 0.000% 0.000% 0.000%MT 3,192 2,910 282 0.282% 0.309% 0.000% 7.3 7.3 16 16 25 25 25 25NC 13,956 12,723 1,233 0.107% 0.102% 0.162% 0.2 0.2 0.3 0.32 0.32 0.31 1.6 1.6 0.32 3.1 3.1 0.32ND 404 341 63 0.248% 0.293% 0.000% 0.71 0.71 0.71 0.71 0.71 0.71 0.71 0.71NE 2,220 2,143 77 0.180% 0.187% 0.000% 2.1 2.1 16.95 16.95 45 45 45 45NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 162 144 18 0.000% 0.000% 0.000%NM 4,347 4,100 247 0.092% 0.098% 0.000% 1.66 1.66 1.86 1.86 2.6 2.6 2.6 2.6NV 1,571 1,163 408 0.064% 0.086% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1NY 2,882 2,170 712 0.069% 0.092% 0.000% 1.3 1.3 1.45 1.45 1.6 1.6 1.6 1.6OH 145 54 91 0.000% 0.000% 0.000%OKOR 2,061 1,579 482 0.000% 0.000% 0.000%RI 740 498 242 0.000% 0.000% 0.000%SC 3,304 2,893 411 0.000% 0.000% 0.000%SD 952 842 110 0.000% 0.000% 0.000%TN 59 12 47 0.000% 0.000% 0.000%TX 2,175 1,343 832 0.092% 0.000% 0.240% 1.8 1.8 1.8 1.8 1.8 1.8 1.8 1.8UT 7,077 5,894 1,183 0.000% 0.000% 0.000%VA 441 148 293 0.000% 0.000% 0.000%VT 1,298 1,104 194 0.154% 0.181% 0.000% 0.18 0.18 0.34 0.34 0.5 0.5 0.5 0.5WI 3,162 3,070 92 0.127% 0.130% 0.000% 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2WV 639 334 305 0.939% 1.497% 0.328% 0.03 0.03 0.5 0.03 0.03 0.5 1 1 0.5 1 1 0.5WY 1,241 934 307 0.000% 0.000% 0.000%Total 121,896 99,807 22,089 0.120% 0.120% 0.118% 0.03 0.03 0.07 0.32 0.385 0.3 9.2 10.55 3 45 45 3

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A31b. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 19 14 5 316,371 84,921 231,450 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 178 129 49 2,781,727 610,396 2,171,331 1.685% 1.550% 2.041% 0.837% 3.149% 0.187%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 918 870 48 6,045,047 2,674,456 3,370,591 0.871% 0.690% 4.167% 8.607% 3.581% 12.594%CA 1,573 1,252 321 33,363,077 12,014,383 21,348,694 0.064% 0.080% 0.000% 0.037% 0.103% 0.000%CO 814 595 219 4,993,497 526,588 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 730 693 37 2,605,694 278,427 2,327,267 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 254 251 3 624,615 343,215 281,400 1.181% 1.195% 0.000% 11.058% 20.124% 0.000%FL 1,318 1,296 22 16,796,064 14,554,059 2,242,005 0.607% 0.617% 0.000% 15.506% 17.895% 0.000%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 1,056 1,023 33 2,543,237 1,434,611 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 870 813 57 1,064,826 808,630 256,196 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,121 1,020 101 9,097,009 2,901,087 6,195,922 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,403 1,359 44 4,867,546 2,547,810 2,319,736 0.143% 0.147% 0.000% 0.009% 0.017% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 2.058% 0.000% 3.333% 7.436% 0.000% 8.095%MA 645 528 117 8,509,903 1,707,521 6,802,382 0.930% 0.758% 1.709% 0.767% 0.845% 0.748%MD 863 795 68 4,906,061 907,954 3,998,107 1.738% 1.509% 4.412% 35.528% 1.441% 43.269%ME 216 190 26 491,237 116,848 374,389 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,918 2,857 61 7,224,067 2,044,211 5,179,856 0.103% 0.105% 0.000% 0.043% 0.151% 0.000%MN 1,288 1,259 29 3,933,642 2,684,001 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,475 1,398 77 3,281,888 1,700,557 1,581,331 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 846 786 60 757,811 365,142 392,669 0.118% 0.127% 0.000% 0.015% 0.030% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.381% 0.314% 1.460% 0.402% 1.162% 0.146%ND 209 182 27 559,198 253,973 305,225 0.478% 0.549% 0.000% 0.657% 1.446% 0.000%NE 739 728 11 1,454,673 678,193 776,480 0.541% 0.549% 0.000% 1.794% 3.848% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 127 116 11 1,969,193 341,973 1,627,220 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 691 656 35 1,656,692 1,395,594 261,098 0.434% 0.457% 0.000% 5.404% 6.415% 0.000%NV 287 266 21 960,268 270,377 689,891 0.348% 0.376% 0.000% 0.177% 0.629% 0.000%NY 1,346 1,116 230 4,923,979 982,289 3,941,690 0.074% 0.090% 0.000% 0.034% 0.172% 0.000%OH 37 28 9 3,029,193 99,582 2,929,611 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,088 938 150 2,937,839 573,089 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 89 80 9 900,695 160,717 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 785 725 60 3,448,394 820,701 2,627,693 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 260 239 21 622,152 262,981 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 11 5 6 648,720 144,963 503,757 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 856 702 154 18,700,247 4,013,688 14,686,559 0.117% 0.000% 0.649% 0.454% 0.000% 0.578%UT 425 388 37 2,500,321 1,667,135 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 173 63 110 2,380,983 26,904 2,354,079 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 440 407 33 432,449 181,285 251,164 0.455% 0.491% 0.000% 0.117% 0.280% 0.000%WI 1,406 1,386 20 3,883,613 2,191,869 1,691,744 0.284% 0.289% 0.000% 0.541% 0.958% 0.000%WV 339 194 145 1,367,412 206,064 1,161,348 1.770% 2.577% 0.690% 0.420% 0.665% 0.377%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 32,713 29,785 2,928 182,919,390 66,425,963 116,493,427 0.266% 0.235% 0.581% 3.087% 4.513% 2.274%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A31c. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 2 2 0 0.787% 0.797% 0.000% 175 175 0 0.028% 0.051% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 111 111 0 0.015% 0.030% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 0.271% 0.275% 0.000% 25,926 25,926 0 1.782% 3.823% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 5 5 0 0.015% 0.017% 0.000% 26,212 26,212 0 0.014% 0.039% 0.000%

Percent of Population Served 

with At Least One Detection 

> 7 μg/L

State

Number of Systems 

with At Least One Detection 

> 7 μg/L

Percent of Systems 

with At Least One Detection 

> 7 μg/L

Population Served by Systems 

with At Least One Detection 

> 7 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A31d. Dinoseb – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 2 2 0 0.787% 0.797% 0.000% 175 175 0 0.028% 0.051% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 111 111 0 0.015% 0.030% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 3 3 0 0.406% 0.412% 0.000% 26,006 26,006 0 1.788% 3.835% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 6 6 0 0.018% 0.020% 0.000% 26,292 26,292 0 0.014% 0.040% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A32. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 20 μg/L 14,021 0 0.000% 45,472,880 0 0.000%	
 14,021 0 0.000% 45,472,880 0 0.000%> 20 μg/L 1,574 0 0.000% 75,149,767 0 0.000%	
 1,574 2 0.127% 75,149,767 68,095 0.091%

> 20 μg/L 15,595 0 0.000% 120,622,647 0 0.000%	
 15,595 2 0.013% 120,622,647 68,095 0.056%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A32a. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 35 17 18 0.000% 0.000% 0.000%AL 644 452 192 0.466% 0.442% 0.521% 2.2 2.2 3.1 3.1 4.575 3.1 6.95 6.95 3.1 6.95 6.95 3.1AR 1,568 1,329 239 0.064% 0.000% 0.418% 2 2 2 2 2 2 2 2AZ 6,308 4,928 1,380 0.333% 0.386% 0.145% 0.4 0.4 0.41 0.6 0.6 0.41 0.99 0.99 0.41 0.99 0.99 0.41CA 11,609 6,863 4,746 0.069% 0.058% 0.084% 0.08 4.6 0.08 4.75 5.55 4 6.9 6.6 6.9 6.9 6.6 6.9CO 2,319 1,653 666 0.216% 0.242% 0.150% 0.5 0.5 1 1 0.95 1 2.2 2.2 1 2.2 2.2 1CT 1,296 988 308 0.000% 0.000% 0.000%DE 3 0 3 0.000% 0.000%FL 2,352 2,288 64 0.553% 0.568% 0.000% 0.35 0.35 0.4 0.4 0.44 0.44 1.6 1.6GA 1,426 1,353 73 0.000% 0.000% 0.000%HIIA 46 30 16 0.000% 0.000% 0.000%ID 1,248 1,034 214 0.000% 0.000% 0.000%IL 4,655 3,950 705 0.000% 0.000% 0.000%IN 2,244 2,081 163 0.134% 0.144% 0.000% 0.4 0.4 0.6 0.6 1.2 1.2 1.2 1.2KY 1,700 434 1,266 0.529% 0.000% 0.711% 0.4 0.4 5 5 13 13 13 13MA 8 2 6 0.000% 0.000% 0.000%MD 171 12 159 0.000% 0.000% 0.000%ME 29 21 8 0.000% 0.000% 0.000%MI 38 21 17 0.000% 0.000% 0.000%MNMOMT 923 833 90 0.000% 0.000% 0.000%NCND 62 39 23 0.000% 0.000% 0.000%NE 1,529 1,477 52 0.131% 0.068% 1.923% 0.9 1.08 0.9 0.99 1.08 0.9 1.08 1.08 0.9 1.08 1.08 0.9NHNJ 1 1 0 0.000% 0.000%NM 4,018 3,786 232 0.199% 0.185% 0.431% 0.17 0.17 0.61 0.605 0.6 0.61 3.2 3.2 0.61 3.2 3.2 0.61NV 1,529 1,132 397 0.523% 0.618% 0.252% 0.55 0.55 0.8 0.785 0.77 0.8 0.98 0.98 0.8 0.98 0.98 0.8NY 83 11 72 0.000% 0.000% 0.000%OH 562 411 151 0.534% 0.730% 0.000% 1.11 1.11 1.27 1.27 2.32 2.32 2.32 2.32OKOR 2,064 1,580 484 0.145% 0.190% 0.000% 0.5 0.5 0.8 0.8 9 9 9 9RI 4 4 0 0.000% 0.000%SC 2,922 2,552 370 0.240% 0.235% 0.270% 4.45 4.45 4.7 6.5 6.5 4.7 6.5 6.5 4.7 6.5 6.5 4.7SD 799 689 110 0.000% 0.000% 0.000%TN 56 10 46 0.000% 0.000% 0.000%TXUT 28 25 3 3.571% 4.000% 0.000% 8.8 8.8 8.8 8.8 8.8 8.8 8.8 8.8VA 128 64 64 0.781% 1.563% 0.000% 5 5 5 5 5 5 5 5VT 13 12 1 0.000% 0.000% 0.000%WI 3,162 3,070 92 0.000% 0.000% 0.000%WV 7 3 4 14.286% 0.000% 25.000% 5 5 5 5 5 5 5 5WY 45 30 15 0.000% 0.000% 0.000%Total 55,634 43,185 12,449 0.174% 0.171% 0.185% 0.08 0.17 0.08 0.8 0.75 2 6.5 6.5 6.9 13 9 13

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A32b. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 10 8 2 30,714 21,750 8,964 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 182 131 51 2,870,462 617,869 2,252,593 1.648% 1.527% 1.961% 1.459% 4.717% 0.565%AR 453 381 72 2,453,233 910,207 1,543,026 0.221% 0.000% 1.389% 0.407% 0.000% 0.648%AZ 900 852 48 6,013,434 2,642,843 3,370,591 1.222% 1.174% 2.083% 4.339% 5.163% 3.694%CA 1,349 1,078 271 32,447,651 11,747,715 20,699,936 0.297% 0.093% 1.107% 13.165% 0.459% 20.376%CO 786 569 217 4,975,162 508,528 4,466,634 0.636% 0.703% 0.461% 0.273% 0.269% 0.273%CT 647 610 37 2,587,527 260,260 2,327,267 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 1 0 1 140,000 0 140,000 0.000% 0.000% 0.000% 0.000%FL 1,309 1,288 21 16,785,435 14,546,259 2,239,176 0.535% 0.543% 0.000% 15.701% 18.118% 0.000%GA 296 283 13 994,603 305,252 689,351 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 3 2 1 162,167 27,550 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 562 535 27 871,773 653,881 217,892 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,148 1,048 100 9,101,501 2,906,279 6,195,222 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,403 1,359 44 4,866,756 2,547,020 2,319,736 0.214% 0.221% 0.000% 0.012% 0.024% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 2.881% 0.000% 4.667% 15.878% 0.000% 17.285%MA 3 2 1 66,881 29,266 37,615 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MD 19 9 10 3,576,031 15,750 3,560,281 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ME 13 10 3 19,662 8,862 10,800 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 19 10 9 3,638,739 29,588 3,609,151 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MNMOMT 605 557 48 685,741 309,762 375,979 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NCND 28 22 6 47,665 40,636 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 736 725 11 1,456,096 679,616 776,480 0.272% 0.138% 9.091% 35.791% 1.322% 65.960%NHNJ 1 1 0 2,061 2,061 0 0.000% 0.000% 0.000% 0.000%NM 672 637 35 1,650,247 1,389,574 260,673 1.042% 0.942% 2.857% 0.680% 0.765% 0.227%NV 287 266 21 960,007 270,116 689,891 2.439% 2.256% 4.762% 1.105% 3.466% 0.180%NY 18 9 9 504,517 19,962 484,555 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 271 192 79 6,470,841 488,501 5,982,340 1.107% 1.563% 0.000% 0.100% 1.330% 0.000%OKOR 1,083 933 150 2,937,422 572,672 2,364,750 0.185% 0.214% 0.000% 1.042% 5.343% 0.000%RI 4 4 0 38,550 38,550 0 0.000% 0.000% 0.000% 0.000%SC 773 714 59 3,436,709 809,926 2,626,783 0.517% 0.420% 1.695% 0.309% 0.034% 0.394%SD 248 227 21 614,853 255,682 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 10 5 5 645,419 144,562 500,857 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TXUT 7 6 1 59,585 54,185 5,400 14.286% 16.667% 0.000% 0.050% 0.055% 0.000%VA 61 39 22 735,027 31,616 703,411 1.639% 2.564% 0.000% 0.082% 1.898% 0.000%VT 13 12 1 77,002 8,079 68,923 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WI 1,407 1,387 20 3,883,613 2,191,869 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 7 3 4 13,887 8,605 5,282 14.286% 0.000% 25.000% 3.593% 0.000% 9.447%WY 18 14 4 189,354 2,567 186,787 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 15,595 14,021 1,574 120,622,647 45,472,880 75,149,767 0.442% 0.357% 1.207% 7.095% 6.430% 7.498%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A32c. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0 0 0 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NCND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJ 0 0 0 0.000% 0.000% 0 0 0 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0 0 0 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 20 μg/L

State

Number of Systems 

with At Least One Detection 

> 20 μg/L

Percent of Systems 

with At Least One Detection 

> 20 μg/L

Population Served by Systems 

with At Least One Detection 

> 20 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A32d. Diquat – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 2 0 2 0.823% 0.000% 1.333% 68,095 0 68,095 1.476% 0.000% 1.607%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NCND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 0 2 0.013% 0.000% 0.127% 68,095 0 68,095 0.056% 0.000% 0.091%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A33. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 100 μg/L 12,632 1 0.008% 44,124,258 20,000 0.045%

	
 12,632 1 0.008% 44,124,258 20,000 0.045%

> 100 μg/L 1,524 2 0.131% 74,412,543 54,657 0.073%

	
 1,524 3 0.197% 74,412,543 66,657 0.090%

> 100 μg/L 14,156 3 0.021% 118,536,801 74,657 0.063%

	
 14,156 4 0.028% 118,536,801 86,657 0.073%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A33a. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 28 10 18 0.000% 0.000% 0.000%AL 530 371 159 0.000% 0.000% 0.000%AR 1,522 1,305 217 0.000% 0.000% 0.000%AZ 6,194 4,789 1,405 0.097% 0.104% 0.071% 9 9 9 9 9 9 9 9 9 9 9 9CA 9,998 5,748 4,250 0.070% 0.052% 0.094% 5 5 55 154.2 5 162.7 548.1 450 548.1 548.1 450 548.1CO 2,310 1,648 662 0.087% 0.121% 0.000% 5.8 5.8 5.8 5.8 5.8 5.8 5.8 5.8CT 22 16 6 0.000% 0.000% 0.000%DE 3 0 3 0.000% 0.000% 0.000%FL 2,355 2,289 66 0.722% 0.699% 1.515% 1.5 1.5 4.4 11.5 11.5 4.4 11.5 11.5 4.4 11.5 11.5 4.4GA 1,427 1,354 73 0.070% 0.074% 0.000% 13.6 13.6 13.6 13.6 13.6 13.6 13.6 13.6HIIA 47 30 17 0.000% 0.000% 0.000%ID 1,248 1,035 213 0.000% 0.000% 0.000%IL 3,014 2,627 387 0.000% 0.000% 0.000%IN 2,235 2,074 161 0.045% 0.048% 0.000% 14 14 14 14 14 14 14 14KY 1,716 442 1,274 0.466% 0.000% 0.628% 0.1 0.1 7.35 7.35 10 10 10 10MA 10 4 6 0.000% 0.000% 0.000%MD 168 11 157 0.595% 0.000% 0.637% 0.21 0.21 0.21 0.21 0.21 0.21 0.21 0.21ME 11 7 4 0.000% 0.000% 0.000%MI 35 21 14 0.000% 0.000% 0.000%MNMOMT 924 834 90 0.000% 0.000% 0.000%NCND 56 38 18 0.000% 0.000% 0.000%NE 35 13 22 0.000% 0.000% 0.000%NHNJ 1 1 0 0.000% 0.000% 0.000%NM 4,065 3,829 236 0.000% 0.000% 0.000%NV 1,529 1,139 390 0.196% 0.088% 0.513% 5 5 9 9 5 9 9 5 9 9 5 9NY 83 7 76 0.000% 0.000% 0.000%OH 775 588 187 0.000% 0.000% 0.000%OKOR 2,105 1,618 487 0.048% 0.062% 0.000% 45 45 45 45 45 45 45 45RI 375 231 144 0.000% 0.000% 0.000%SC 2,929 2,533 396 0.000% 0.000% 0.000%SD 753 643 110 0.000% 0.000% 0.000%TN 56 10 46 0.000% 0.000% 0.000%TXUT 26 25 1 3.846% 4.000% 0.000% 9.9 9.9 9.9 9.9 9.9 9.9 9.9 9.9VA 3 1 2 0.000% 0.000% 0.000%VT 12 11 1 0.000% 0.000% 0.000%WI 3,169 3,078 91 0.000% 0.000% 0.000%WV 5 3 2 0.000% 0.000% 0.000%WY 46 31 15 0.000% 0.000% 0.000%Total 49,820 38,414 11,406 0.096% 0.081% 0.149% 0.1 1.5 0.1 9.8 11.5 9 55 13.6 171.2 548.1 450 548.1

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A33b. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 6 4 2 22,245 13,281 8,964 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 172 126 46 3,363,471 589,449 2,774,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 910 862 48 6,050,529 2,679,938 3,370,591 0.330% 0.232% 2.083% 5.796% 1.890% 8.901%CA 1,255 979 276 32,564,499 11,127,358 21,437,141 0.398% 0.204% 1.087% 0.271% 0.195% 0.311%CO 787 570 217 4,975,562 508,928 4,466,634 0.127% 0.175% 0.000% 0.001% 0.012% 0.000%CT 19 16 3 154,122 3,675 150,447 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 1 0 1 140,000 0 140,000 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,308 1,287 21 16,750,864 14,511,688 2,239,176 0.841% 0.777% 4.762% 19.027% 21.261% 4.550%GA 296 283 13 994,603 305,252 689,351 0.338% 0.353% 0.000% 2.852% 9.292% 0.000%HIIA 3 2 1 162,167 27,550 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 565 538 27 871,868 653,976 217,892 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,148 1,048 100 9,104,311 2,909,089 6,195,222 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.071% 0.074% 0.000% 0.003% 0.006% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 2.469% 0.000% 4.000% 8.989% 0.000% 9.785%MA 5 4 1 67,041 29,426 37,615 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MD 17 8 9 3,563,515 4,750 3,558,765 5.882% 0.000% 11.111% 47.986% 0.000% 48.050%ME 7 4 3 19,558 9,484 10,074 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 18 11 7 3,597,572 29,838 3,567,734 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MNMOMT 606 558 48 685,991 310,012 375,979 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NCND 28 22 6 47,665 40,636 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 18 8 10 791,975 15,888 776,087 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NHNJ 1 1 0 2,061 2,061 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 671 637 34 1,654,483 1,393,835 260,648 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 288 267 21 960,447 270,556 689,891 0.694% 0.375% 4.762% 34.830% 0.055% 48.467%NY 18 6 12 548,606 17,893 530,713 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 292 214 78 6,543,054 568,814 5,974,240 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,081 931 150 2,938,337 573,587 2,364,750 0.093% 0.107% 0.000% 0.010% 0.052% 0.000%RI 47 38 9 889,968 149,990 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 781 721 60 3,460,504 832,811 2,627,693 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 247 226 21 600,752 241,581 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 10 5 5 645,419 144,562 500,857 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TXUT 8 7 1 257,795 105,535 152,260 12.500% 14.286% 0.000% 0.012% 0.028% 0.000%VA 2 1 1 5,726 650 5,076 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 12 11 1 76,640 7,717 68,923 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WI 1,406 1,386 20 3,883,588 2,191,844 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 5 3 2 11,455 8,605 2,850 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WY 19 15 4 198,034 11,247 186,787 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 14,156 12,632 1,524 118,536,801 44,124,258 74,412,543 0.233% 0.158% 0.853% 5.158% 7.222% 3.934%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A33c. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 3 1 2 0.239% 0.102% 0.725% 74,657 20,000 54,657 0.229% 0.180% 0.255%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NCND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 3 1 2 0.021% 0.008% 0.131% 74,657 20,000 54,657 0.063% 0.045% 0.073%

Percent of Population Served 

with At Least One Detection 

> 100 μg/L

State

Number of Systems 

with At Least One Detection 

> 100 μg/L

Percent of Systems 

with At Least One Detection 

> 100 μg/L

Population Served by Systems 

with At Least One Detection 

> 100 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A33d. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 4 1 3 0.319% 0.102% 1.087% 86,657 20,000 66,657 0.266% 0.180% 0.311%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NCND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 4 1 3 0.028% 0.008% 0.197% 86,657 20,000 66,657 0.073% 0.045% 0.090%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A34. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 2 μg/L 29,734 1 0.003% 67,885,419 300 0.000%	
 29,734 2 0.007% 67,885,419 2,800 0.004%

> 2 μg/L 3,049 0 0.000% 116,157,743 0 0.000%

	
 3,049 0 0.000% 116,157,743 0 0.000%

> 2 μg/L 32,783 1 0.003% 184,043,162 300 0.000%	
 32,783 2 0.006% 184,043,162 2,800 0.002%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A34a. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 104 53 51 0.000% 0.000% 0.000%AL 548 402 146 0.000% 0.000% 0.000%AR 1,664 1,423 241 0.000% 0.000% 0.000%AZ 7,257 5,687 1,570 0.000% 0.000% 0.000%CA 14,264 8,235 6,029 0.035% 0.061% 0.000% 0.007 0.007 1.7 1.7 3.3 3.3 3.3 3.3CO 2,525 1,825 700 0.000% 0.000% 0.000%CT 1,584 1,006 578 0.442% 0.000% 1.211% 0.01 0.01 0.1 0.1 0.1 0.1 0.1 0.1DE 758 729 29 0.000% 0.000% 0.000%FL 2,396 2,329 67 0.459% 0.472% 0.000% 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008GA 1,482 1,402 80 0.000% 0.000% 0.000%HI 2,101 2,004 97 0.000% 0.000% 0.000%IA 148 131 17 0.000% 0.000% 0.000%ID 1,742 1,484 258 0.000% 0.000% 0.000%IL 3,866 3,129 737 0.000% 0.000% 0.000%IN 2,233 2,069 164 0.000% 0.000% 0.000%KY 1,759 446 1,313 0.341% 0.000% 0.457% 0.001 0.001 0.3 0.3 0.5 0.5 0.5 0.5MA 3,015 2,227 788 0.100% 0.000% 0.381% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01MD 2,741 1,725 1,016 0.292% 0.000% 0.787% 0.03 0.03 0.06 0.06 0.52 0.52 0.52 0.52ME 458 404 54 0.000% 0.000% 0.000%MI 6,768 6,317 451 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 5,560 4,692 868 0.036% 0.043% 0.000% 0.11 0.11 0.125 0.125 0.14 0.14 0.14 0.14MT 3,006 2,698 308 0.000% 0.000% 0.000%NC 13,597 12,464 1,133 0.066% 0.064% 0.088% 0.01 0.01 0.04 0.01 0.01 0.04 0.08 0.08 0.04 0.08 0.08 0.04ND 410 344 66 0.488% 0.581% 0.000% 0.02 0.02 0.075 0.075 0.13 0.13 0.13 0.13NE 4,480 4,131 349 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 35 31 4 0.000% 0.000% 0.000%NM 4,357 4,107 250 0.000% 0.000% 0.000%NV 1,643 1,207 436 0.000% 0.000% 0.000%NY 2,947 2,205 742 0.000% 0.000% 0.000%OH 234 98 136 0.000% 0.000% 0.000%OKOR 2,054 1,571 483 0.000% 0.000% 0.000%RI 601 414 187 0.333% 0.483% 0.000% 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005SC 2,966 2,572 394 0.000% 0.000% 0.000%SD 953 844 109 0.000% 0.000% 0.000%TN 65 12 53 0.000% 0.000% 0.000%TX 11,038 5,279 5,759 0.000% 0.000% 0.000%UT 7,091 5,907 1,184 0.000% 0.000% 0.000%VA 506 178 328 0.000% 0.000% 0.000%VT 1,310 1,108 202 0.076% 0.090% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1WI 3,187 3,094 93 0.031% 0.032% 0.000% 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05WV 646 336 310 2.167% 2.679% 1.613% 0.0025 0.0025 0.0035 0.0035 0.0035 0.01 0.5 0.5 0.5 0.5 0.5 0.5WY 1,283 964 319 0.000% 0.000% 0.000%Total 134,336 105,777 28,559 0.053% 0.039% 0.105% 0.001 0.0025 0.001 0.02 0.008 0.07 0.5 0.14 0.5 3.3 3.3 0.52

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A34b. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 16 10 6 246,416 14,306 232,110 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 181 133 48 2,794,663 636,554 2,158,109 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 450 379 71 2,447,627 905,863 1,541,764 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 949 901 48 6,081,248 2,710,657 3,370,591 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CA 1,627 1,333 294 33,812,994 12,091,504 21,721,490 0.246% 0.300% 0.000% 0.156% 0.437% 0.000%CO 808 589 219 4,990,621 523,712 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 655 617 38 2,595,773 261,886 2,333,887 0.611% 0.000% 10.526% 17.130% 0.000% 19.052%DE 201 198 3 628,982 347,582 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,315 1,294 21 16,791,489 14,552,313 2,239,176 0.380% 0.386% 0.000% 15.509% 17.895% 0.000%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 112 100 12 1,305,882 1,251,254 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 95 93 2 238,934 99,549 139,385 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 722 675 47 978,730 742,054 236,676 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,132 1,031 101 9,103,070 2,907,148 6,195,922 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,401 1,357 44 4,866,676 2,546,940 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 1.646% 0.000% 2.667% 7.137% 0.000% 7.769%MA 644 527 117 8,485,298 1,682,916 6,802,382 0.311% 0.000% 1.709% 0.870% 0.000% 1.086%MD 862 794 68 4,906,096 907,989 3,998,107 0.348% 0.000% 4.412% 69.819% 0.000% 85.675%ME 263 238 25 487,341 116,684 370,657 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,930 2,869 61 7,226,540 2,046,684 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,471 1,395 76 2,644,644 1,700,183 944,461 0.068% 0.072% 0.000% 0.004% 0.006% 0.000%MT 813 753 60 753,259 360,590 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.296% 0.269% 0.730% 0.135% 0.347% 0.064%ND 208 181 27 559,142 253,917 305,225 0.962% 1.105% 0.000% 0.091% 0.200% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 31 29 2 1,076,429 142,635 933,794 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 695 659 36 1,662,962 1,400,064 262,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 291 270 21 960,972 271,081 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,348 1,117 231 4,924,821 981,544 3,943,277 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 46 36 10 3,537,892 147,360 3,390,532 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,084 934 150 2,937,104 572,354 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 86 77 9 902,061 162,083 739,978 1.163% 1.299% 0.000% 0.022% 0.123% 0.000%SC 773 714 59 3,427,802 801,019 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 12 6 6 655,614 145,112 510,502 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,386 1,667,200 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 183 71 112 2,403,715 30,317 2,373,398 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 442 409 33 432,910 181,746 251,164 0.226% 0.244% 0.000% 0.071% 0.169% 0.000%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.071% 0.072% 0.000% 0.001% 0.002% 0.000%WV 343 196 147 1,368,815 204,156 1,164,659 3.499% 4.592% 2.041% 0.829% 0.971% 0.804%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 32,783 29,734 3,049 184,043,162 67,885,419 116,157,743 0.143% 0.101% 0.558% 3.777% 3.927% 3.690%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A34c. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.061% 0.075% 0.000% 300 300 0 0.001% 0.002% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 1 0 0.003% 0.003% 0.000% 300 300 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 2 μg/L

State

Number of Systems 

with At Least One Detection 

> 2 μg/L

Percent of Systems 

with At Least One Detection 

> 2 μg/L

Population Served by Systems 

with At Least One Detection 

> 2 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A34d. Endrin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 2 2 0 0.123% 0.150% 0.000% 2,800 2,800 0 0.008% 0.023% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 2 0 0.006% 0.007% 0.000% 2,800 2,800 0 0.002% 0.004% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A35. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 700 μg/L 46,190 0 0.000% 86,398,177 0 0.000%	
 46,190 2 0.004% 86,398,177 5,961 0.007%

> 700 μg/L 4,257 0 0.000% 140,541,198 0 0.000%

	
 4,257 0 0.000% 140,541,198 0 0.000%

> 700 μg/L 50,447 0 0.000% 226,939,375 0 0.000%	
 50,447 2 0.004% 226,939,375 5,961 0.003%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A35a. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,385 2,220 1,165 3.663% 1.532% 7.725% 0.1 0.1 0.22 1.205 0.655 2.175 47.4 2.21 66.3 97.5 15 97.5AL 849 622 227 4.594% 5.627% 1.762% 0.5 0.5 0.5 0.97 0.97 0.95 8.99 8.99 4.1 25.6 25.6 4.1AR 2,394 1,926 468 3.133% 3.738% 0.641% 0.11 0.11 0.2 0.62 0.635 0.61 2.11 2.11 0.75 6.62 6.62 0.75AZ 11,711 9,547 2,164 1.272% 1.288% 1.201% 0.5 0.5 0.5 1 1 1 3.3 2.5 6.1 66 35 66CA 86,361 45,803 40,558 0.076% 0.079% 0.074% 0.5 0.5 0.52 0.975 0.7 1.165 11.8 12 10.55 21 21 18.6CO 2,910 2,154 756 2.474% 2.228% 3.175% 0.08 0.08 0.3 0.88 0.82 1.1 10 17 2.7 63 63 3.5CT 6,944 6,053 891 0.403% 0.463% 0.000% 0.6 0.6 1.2 1.2 5.4 5.4 9.4 9.4DE 1,051 1,021 30 1.903% 1.959% 0.000% 0.51 0.51 2.84 2.84 23.4 23.4 52.8 52.8FL 4,190 4,122 68 2.411% 2.450% 0.000% 0.06 0.06 0.81 0.81 3.1 3.1 250 250GA 7,175 6,348 827 1.519% 1.670% 0.363% 0.5 0.5 0.53 0.88 0.875 1 3.2 3.2 1.1 10 10 1.1HI 1,790 1,687 103 0.000% 0.000% 0.000%IA 1,942 1,811 131 3.038% 2.982% 3.817% 0.1 0.1 0.6 0.9 0.85 0.9 3.6 2.5 7.2 7.2 6.6 7.2ID 3,740 3,279 461 0.107% 0.091% 0.217% 0.3 0.3 1.5 1.165 0.83 1.5 1.6 1.6 1.5 1.6 1.6 1.5IL 7,071 6,511 560 1.542% 1.659% 0.179% 0.5 0.5 0.53 0.8 0.8 0.53 2.22 2.22 0.53 12.5 12.5 0.53IN 4,621 4,311 310 0.346% 0.348% 0.323% 0.6 0.6 0.97 0.9 0.9 0.97 3.9 3.9 0.97 9.7 9.7 0.97KY 3,311 1,127 2,184 1.268% 1.154% 1.328% 0.002 0.2 0.002 0.6 0.8 0.5 2.4 8.2 1 14 14 3MA 16,249 12,259 3,990 0.302% 0.302% 0.301% 0.5 0.5 0.52 1.1 1 1.495 2.7 1.9 3.12 33 6 33MD 6,774 5,512 1,262 1.491% 1.796% 0.158% 0.1 0.1 0.8 1.1 1.2 0.8 3.9 4 0.8 13.7 13.7 0.8ME 3,702 3,383 319 0.378% 0.236% 1.881% 0.5 0.5 0.5 0.75 0.65 0.95 6.7 8.5 1.5 8.5 8.5 1.5MI 10,752 9,742 1,010 0.419% 0.328% 1.287% 0.5 0.5 0.5 1 0.9 1.3 3.2 3.2 2.6 13.3 13.3 3.2MN 8,620 7,363 1,257 2.378% 1.779% 5.887% 0.2 0.2 0.2 0.3 0.4 0.3 1.4 1.4 1.4 29 29 15MO 7,543 6,694 849 1.180% 1.285% 0.353% 0.5 0.5 0.5 1 1 1.72 3.3 2.96 3.88 42.5 42.5 3.88MT 4,493 3,954 539 0.690% 0.632% 1.113% 0.54 0.54 0.66 1.4 1.8 1.3 6 6 1.6 17.9 17.9 1.6NC 19,062 17,483 1,579 3.200% 3.443% 0.507% 0.5 0.5 0.5 1.1 1.1 0.925 6.2 6.2 5.19 557 557 5.19ND 568 432 136 1.937% 2.546% 0.000% 0.54 0.54 0.96 0.96 2.59 2.59 39 39NE 6,840 6,264 576 0.102% 0.112% 0.000% 0.96 0.96 2.2 2.2 5.3 5.3 5.3 5.3NH 9,583 9,105 478 0.292% 0.308% 0.000% 0.38 0.38 1 1 10 10 24 24NJ 20,327 18,543 1,784 0.497% 0.518% 0.280% 0.1 0.1 0.2 0.6 0.6 0.5 3 3 0.9 72 72 0.9NM 6,572 6,097 475 0.700% 0.689% 0.842% 0.12 0.12 0.17 0.725 0.795 0.3 4.4 4.4 0.68 15.9 15.9 0.68NV 3,210 2,578 632 0.405% 0.388% 0.475% 0.7 0.7 1.65 1.7 2.05 1.65 5.8 9.25 2.16 12.7 12.7 2.16NY 7,140 5,465 1,675 0.756% 0.732% 0.836% 0.5 0.5 0.5 0.95 0.9 0.95 5 5.3 1.93 12 11.2 12OH 8,848 7,688 1,160 0.972% 1.067% 0.345% 0.5 0.5 0.52 1.5 1.505 0.7 6.74 6.74 2 105 105 2OK 5,355 3,958 1,397 1.737% 1.920% 1.217% 0.3 0.3 0.5 1 0.95 1 4.3 5.2 2.57 23.3 23.3 4.5OR 2,328 1,685 643 0.301% 0.119% 0.778% 0.5 0.5 0.5 0.51 0.6 0.51 1.1 0.7 1.1 1.1 0.7 1.1RI 1,959 1,591 368 0.306% 0.189% 0.815% 2 2 4.2 3.35 2.5 4.29 7.9 2.5 7.9 7.9 2.5 7.9SC 4,342 3,805 537 0.599% 0.657% 0.186% 0.1 0.1 1.67 1 1 1.67 3.17 3.17 1.67 6.61 6.61 1.67SD 889 855 34 0.225% 0.234% 0.000% 0.21 0.21 0.28 0.28 0.35 0.35 0.35 0.35TN 2,935 1,163 1,772 0.102% 0.086% 0.113% 0.5 0.8 0.5 0.56 0.8 0.53 0.8 0.8 0.56 0.8 0.8 0.56TX 34,219 27,101 7,118 2.686% 3.000% 1.489% 0.5 0.5 0.5 1 1 0.965 4.4 5.1 3.1 386.07 386.07 8.1UT 8,990 7,559 1,431 0.178% 0.132% 0.419% 0.6 0.6 1.2 2.8 4.3 1.4 9 9 85 85 9 85VA 4,930 4,057 873 2.535% 2.835% 1.145% 0.5 0.5 0.5 1.2 1.1 1.55 4.8 4.3 7.45 64 64 9.1VT 4,357 3,963 394 0.230% 0.202% 0.508% 0.2 0.2 3.4 1.85 1.25 3.9 4.7 5 4.4 5 5 4.4WI 11,297 11,173 124 0.894% 0.904% 0.000% 0.02 0.02 0.31 0.31 2.5 2.5 340 340WV 1,149 449 700 2.089% 3.563% 1.143% 0.09 0.09 0.4 0.5 0.5 0.6 1 0.6 1.4 1.4 0.8 1.4WY 1,663 1,159 504 1.022% 1.381% 0.198% 0.3 0.43 0.3 0.7 0.705 0.3 3 3 0.3 3.9 3.9 0.3Total 374,141 289,622 84,519 1.030% 1.146% 0.629% 0.002 0.02 0.002 0.9 0.9 0.9 4.6 4.4 6 557 557 97.5

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A35b. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 5.806% 3.165% 14.384% 4.748% 5.660% 4.180%AL 264 203 61 4,219,181 1,124,093 3,095,088 10.606% 12.315% 4.918% 6.592% 13.500% 4.082%AR 454 382 72 2,453,348 910,322 1,543,026 7.489% 8.377% 2.778% 3.025% 6.791% 0.803%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 5.382% 4.847% 16.667% 52.627% 38.355% 64.466%CA 3,661 3,144 517 35,830,513 13,518,052 22,312,461 1.120% 0.763% 3.288% 17.451% 4.104% 25.538%CO 827 606 221 4,997,906 530,272 4,467,634 5.200% 5.776% 3.620% 1.829% 5.953% 1.339%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.829% 0.856% 0.000% 0.145% 1.016% 0.000%DE 318 315 3 698,987 417,587 281,400 4.717% 4.762% 0.000% 16.911% 28.307% 0.000%FL 1,513 1,487 26 17,497,981 15,251,939 2,246,042 3.106% 3.161% 0.000% 3.137% 3.598% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 3.403% 3.517% 1.724% 2.981% 8.161% 1.581%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,057 1,024 33 2,543,315 1,434,689 1,108,626 3.595% 3.320% 12.121% 1.917% 2.638% 0.984%ID 935 878 57 1,093,666 837,604 256,062 0.428% 0.342% 1.754% 0.139% 0.119% 0.205%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 3.429% 3.623% 0.962% 1.333% 3.920% 0.074%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.543% 0.490% 2.273% 2.452% 4.660% 0.004%KY 241 92 149 4,602,392 375,363 4,227,029 10.788% 8.696% 12.081% 13.326% 6.332% 13.947%MA 718 600 118 8,557,325 1,749,901 6,807,424 3.482% 2.667% 7.627% 4.208% 9.722% 2.791%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 4.459% 4.564% 2.941% 1.377% 5.955% 0.203%ME 810 757 53 728,347 292,773 435,574 0.988% 0.925% 1.887% 19.099% 0.739% 31.440%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.908% 0.687% 11.475% 51.990% 13.190% 66.805%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 7.080% 6.186% 53.333% 19.959% 20.810% 17.907%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 3.881% 3.881% 3.896% 3.753% 5.885% 1.012%MT 848 788 60 757,949 365,280 392,669 1.061% 0.888% 3.333% 1.153% 1.876% 0.481%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 10.689% 11.176% 2.878% 6.380% 17.652% 2.670%ND 210 183 27 562,397 257,172 305,225 2.857% 3.279% 0.000% 1.121% 2.452% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.778% 0.789% 0.000% 0.502% 1.071% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 1.351% 1.397% 0.000% 0.902% 2.144% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 4.149% 4.115% 5.405% 3.992% 8.958% 1.317%NM 727 688 39 1,698,980 1,432,432 266,548 3.301% 3.052% 7.692% 32.666% 37.712% 5.548%NV 338 317 21 973,592 283,701 689,891 2.367% 1.893% 9.524% 1.577% 4.550% 0.354%NY 1,526 1,290 236 4,895,109 1,044,507 3,850,602 2.556% 2.093% 5.085% 6.497% 2.627% 7.547%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 1.595% 1.649% 0.800% 0.155% 0.441% 0.028%OK 718 506 212 3,119,686 660,832 2,458,854 5.432% 5.929% 4.245% 1.630% 4.409% 0.884%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.547% 0.212% 2.632% 0.228% 0.123% 0.253%RI 145 136 9 913,884 173,906 739,978 3.448% 1.471% 33.333% 20.600% 24.496% 19.685%SC 819 757 62 3,356,831 732,879 2,623,952 2.442% 2.510% 1.613% 1.410% 6.393% 0.019%SD 245 233 12 266,416 194,218 72,198 0.408% 0.429% 0.000% 1.342% 1.840% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.855% 0.617% 1.058% 0.770% 0.597% 0.830%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 10.402% 9.980% 16.082% 28.175% 33.148% 25.252%UT 500 454 46 2,553,197 1,698,877 854,320 1.600% 1.322% 4.348% 8.073% 2.787% 18.586%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 3.375% 3.429% 2.924% 2.493% 10.486% 1.407%VT 603 560 43 491,035 227,067 263,968 1.327% 1.250% 2.326% 0.622% 1.022% 0.278%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 3.083% 3.118% 0.000% 9.091% 15.642% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 5.459% 6.173% 4.375% 3.093% 3.209% 3.070%WY 304 256 48 446,177 129,229 316,948 4.276% 4.688% 2.083% 5.933% 2.809% 7.207%Total 50,447 46,190 4,257 226,939,375 86,398,177 140,541,198 3.909% 3.750% 5.638% 11.857% 10.518% 12.681%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A35c. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 700 μg/L

State

Number of Systems 

with At Least One Detection 

> 700 μg/L

Percent of Systems 

with At Least One Detection 

> 700 μg/L

Population Served by Systems 

with At Least One Detection 

> 700 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A35d. Ethylbenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 45 45 0 0.001% 0.003% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 5,916 5,916 0 0.024% 0.064% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 2 0 0.004% 0.004% 0.000% 5,961 5,961 0 0.003% 0.007% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A36. Ethylene dibromide (EDB) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.05 μg/L 33,245 67 0.202% 72,299,607 449,648 0.622%

	
 33,245 96 0.289% 72,299,607 1,143,149 1.581%

> 0.05 μg/L 2,970 21 0.707% 115,854,308 1,810,412 1.563%

	
 2,970 26 0.875% 115,854,308 1,894,232 1.635%

> 0.05 μg/L 36,215 88 0.243% 188,153,915 2,260,060 1.201%

	
 36,215 122 0.337% 188,153,915 3,037,381 1.614%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A36a. Ethylene dibromide (EDB) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 1,457 930 527 0.000% 0.000% 0.000%AL 652 482 170 2.914% 2.697% 3.529% 0.00139 0.00139 0.02 0.17 0.24 0.155 0.32 0.31 0.35 0.35 0.32 0.35AR 4,115 3,375 740 0.122% 0.148% 0.000% 0.00292 0.00292 0.02 0.02 0.03 0.03 0.03 0.03AZ 6,234 4,842 1,392 0.225% 0.186% 0.359% 0.01 0.01 0.01 0.01 0.01 0.01 0.42 0.42 0.5 0.5 0.42 0.5CA 48,322 27,484 20,838 2.038% 1.754% 2.414% 0.01 0.01 0.01 0.04 0.03 0.05 0.19 0.29 0.16 0.5 0.5 0.46CO 2,576 1,880 696 0.272% 0.319% 0.144% 0.01 0.01 0.02 0.13 0.15 0.02 0.4 0.4 0.02 0.4 0.4 0.02CT 1,500 1,168 332 1.000% 0.599% 2.410% 0.02 0.02 0.02 0.03 0.08 0.02 0.19 0.12 0.19 0.19 0.12 0.19DE 2,273 2,213 60 0.176% 0.181% 0.000% 0.03 0.03 0.04 0.04 0.06 0.06 0.06 0.06FL 2,438 2,373 65 0.738% 0.759% 0.000% 0.003 0.003 0.008 0.008 0.1 0.1 0.11 0.11GA 8,860 7,955 905 0.023% 0.025% 0.000% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02HI 3,057 2,966 91 0.262% 0.270% 0.000% 0.01 0.01 0.11 0.11 0.19 0.19 0.19 0.19IA 85 68 17 0.000% 0.000% 0.000%ID 1,793 1,571 222 0.279% 0.318% 0.000% 0.01 0.01 0.05 0.05 0.06 0.06 0.06 0.06IL 3,942 3,490 452 0.000% 0.000% 0.000%IN 2,271 2,093 178 0.088% 0.048% 0.562% 0.01 0.01 0.03 0.02 0.01 0.03 0.03 0.01 0.03 0.03 0.01 0.03KY 1,724 433 1,291 0.928% 0.000% 1.239% 0.01 0.01 0.02 0.02 0.02 0.02 0.03 0.03MA 3,022 2,160 862 0.232% 0.093% 0.580% 0.01 0.01 0.02 0.02 0.015 0.02 0.02 0.02 0.02 0.02 0.02 0.02MDME 2,194 2,036 158 0.000% 0.000% 0.000%MI 5,362 4,847 515 0.000% 0.000% 0.000%MN 8,585 7,336 1,249 0.000% 0.000% 0.000%MO 7,543 6,694 849 0.000% 0.000% 0.000%MT 1,196 1,080 116 0.000% 0.000% 0.000%NC 12,730 11,856 874 0.479% 0.489% 0.343% 0.01 0.01 0.09 0.09 0.085 0.1 0.29 0.29 0.36 1.1 1.1 0.36ND 70 45 25 0.000% 0.000% 0.000%NE 9,184 8,526 658 0.327% 0.352% 0.000% 0.01 0.01 0.02 0.02 0.065 0.065 0.08 0.08NH 4,043 3,874 169 0.000% 0.000% 0.000%NJ 19,718 18,259 1,459 0.036% 0.038% 0.000% 0.0017 0.0017 0.07 0.07 0.5 0.5 0.5 0.5NM 942 883 59 0.106% 0.113% 0.000% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01NV 2,386 1,875 511 0.042% 0.000% 0.196% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02NY 478 336 142 0.628% 0.595% 0.704% 0.00293 0.00293 0.03 0.0031 0.00302 0.03 0.03 0.0031 0.03 0.03 0.0031 0.03OH 43 12 31 0.000% 0.000% 0.000%OKOR 2,048 1,565 483 0.195% 0.256% 0.000% 0.01 0.01 0.475 0.475 1.6 1.6 1.6 1.6RI 2,253 1,777 476 0.000% 0.000% 0.000%SC 3,243 2,789 454 2.158% 2.331% 1.101% 0.00329 0.00329 0.5 0.185 0.18 0.5 0.5 0.5 0.5 0.5 0.5 0.5SD 1,492 1,366 126 0.000% 0.000% 0.000%TN 53 11 42 0.000% 0.000% 0.000%TX 34,144 27,040 7,104 0.000% 0.000% 0.000%UT 11 11 0 0.000% 0.000% 0.000%VA 446 214 232 0.000% 0.000% 0.000%VT 1,387 1,218 169 0.144% 0.164% 0.000% 0.005 0.005 0.0075 0.0075 0.01 0.01 0.01 0.01WI 2,909 2,878 31 0.413% 0.417% 0.000% 0.01 0.01 0.015 0.015 0.09 0.09 0.23 0.23WV 685 358 327 1.460% 1.955% 0.917% 0.0027 0.0027 0.01 0.01 0.0027 0.01 0.255 0.01 0.5 0.5 0.01 0.5WY 1,331 1,002 329 0.075% 0.100% 0.000% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2Total 218,797 173,371 45,426 0.598% 0.433% 1.228% 0.00139 0.00139 0.01 0.04 0.04 0.04 0.23 0.33 0.16 1.6 1.6 0.5

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A36b. Ethylene dibromide (EDB) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 572 430 142 594,149 222,065 372,084 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 187 139 48 2,890,272 733,275 2,156,997 6.417% 5.036% 10.417% 9.190% 8.243% 9.512%AR 454 382 72 2,453,348 910,322 1,543,026 1.101% 1.309% 0.000% 0.849% 2.288% 0.000%AZ 933 885 48 6,055,029 2,684,438 3,370,591 0.750% 0.565% 4.167% 29.211% 3.544% 49.652%CA 2,190 1,888 302 34,482,521 12,806,498 21,676,023 2.055% 1.642% 4.636% 19.134% 8.069% 25.672%CO 819 600 219 4,994,387 529,503 4,464,884 0.366% 0.333% 0.457% 0.263% 0.174% 0.273%CT 711 673 38 2,608,625 274,738 2,333,887 0.703% 0.446% 5.263% 5.066% 5.074% 5.065%DE 332 329 3 707,346 425,946 281,400 0.301% 0.304% 0.000% 0.031% 0.052% 0.000%FL 1,313 1,292 21 16,794,862 14,555,686 2,239,176 0.609% 0.619% 0.000% 15.521% 17.909% 0.000%GA 1,825 1,709 116 7,485,941 1,593,160 5,892,781 0.055% 0.059% 0.000% 0.002% 0.008% 0.000%HI 109 97 12 1,300,349 1,245,721 54,628 2.752% 3.093% 0.000% 14.572% 15.211% 0.000%IA 37 36 1 187,920 53,303 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 657 630 27 929,336 710,707 218,629 0.304% 0.317% 0.000% 0.452% 0.591% 0.000%IL 1,369 1,265 104 9,186,672 2,986,275 6,200,397 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.143% 0.074% 2.273% 0.055% 0.043% 0.069%KY 243 93 150 4,612,320 375,460 4,236,860 4.115% 0.000% 6.667% 12.719% 0.000% 13.846%MA 634 523 111 8,407,483 1,680,317 6,727,166 0.946% 0.382% 3.604% 2.149% 0.954% 2.447%MDME 741 688 53 719,849 284,275 435,574 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,035 1,975 60 6,883,399 1,707,109 5,176,290 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 646 596 50 693,590 318,486 375,104 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,361 2,228 133 6,786,602 1,733,551 5,053,051 0.932% 0.853% 2.256% 1.389% 1.137% 1.475%ND 28 22 6 47,665 40,636 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 773 762 11 1,462,281 685,801 776,480 0.776% 0.787% 0.000% 0.764% 1.630% 0.000%NH 1,214 1,196 18 614,066 395,955 218,111 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 1,397 1,360 37 7,747,090 2,711,144 5,035,946 0.501% 0.515% 0.000% 1.015% 2.902% 0.000%NM 282 267 15 1,419,356 1,213,960 205,396 0.355% 0.375% 0.000% 3.662% 4.282% 0.000%NV 312 292 20 968,859 279,060 689,799 0.321% 0.000% 5.000% 5.832% 0.000% 8.191%NY 312 235 77 1,292,868 350,979 941,889 0.641% 0.426% 1.299% 1.069% 0.480% 1.288%OH 11 5 6 2,733,428 92,894 2,640,534 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,083 933 150 2,937,054 572,304 2,364,750 0.185% 0.214% 0.000% 0.316% 1.622% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 783 723 60 3,445,274 811,841 2,633,433 3.831% 3.734% 5.000% 9.745% 8.558% 10.111%SD 292 271 21 655,146 295,975 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 9 5 4 590,798 109,942 480,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 2 2 0 23,030 23,030 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 177 82 95 2,172,380 34,176 2,138,204 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 462 428 34 448,513 197,148 251,365 0.433% 0.467% 0.000% 0.169% 0.384% 0.000%WI 768 757 11 2,848,014 1,599,536 1,248,478 0.391% 0.396% 0.000% 0.038% 0.068% 0.000%WV 341 196 145 1,370,807 206,634 1,164,173 2.346% 3.571% 0.690% 0.414% 0.633% 0.376%WY 304 256 48 446,177 129,229 316,948 0.329% 0.391% 0.000% 0.022% 0.077% 0.000%Total 36,215 33,245 2,970 188,153,915 72,299,607 115,854,308 0.538% 0.442% 1.616% 6.924% 5.930% 7.544%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A36c. Ethylene dibromide (EDB) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 7 3 4 3.743% 2.158% 8.333% 195,362 11,114 184,248 6.759% 1.516% 8.542%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 3 2 1 0.322% 0.226% 2.083% 165,250 25,250 140,000 2.729% 0.941% 4.154%CA 18 10 8 0.822% 0.530% 2.649% 1,342,592 278,791 1,063,801 3.894% 2.177% 4.908%CO 2 2 0 0.244% 0.333% 0.000% 920 920 0 0.018% 0.174% 0.000%CT 2 1 1 0.281% 0.149% 2.632% 77,279 77 77,202 2.962% 0.028% 3.308%DE 1 1 0 0.301% 0.304% 0.000% 222 222 0 0.031% 0.052% 0.000%FL 1 1 0 0.076% 0.077% 0.000% 1,248 1,248 0 0.007% 0.009% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 1 1 0 0.917% 1.031% 0.000% 60 60 0 0.005% 0.005% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 1 1 0 0.152% 0.159% 0.000% 88 88 0 0.009% 0.012% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MDME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 12 9 3 0.508% 0.404% 2.256% 83,394 8,868 74,526 1.229% 0.512% 1.475%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 0.259% 0.262% 0.000% 215 215 0 0.015% 0.031% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 5 5 0 0.358% 0.368% 0.000% 48,877 48,877 0 0.631% 1.803% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 2 2 0 0.185% 0.214% 0.000% 9,281 9,281 0 0.316% 1.622% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 28 25 3 3.576% 3.458% 5.000% 330,413 64,152 266,261 9.590% 7.902% 10.111%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.130% 0.132% 0.000% 385 385 0 0.014% 0.024% 0.000%WV 1 0 1 0.293% 0.000% 0.690% 4,374 0 4,374 0.319% 0.000% 0.376%WY 1 1 0 0.329% 0.391% 0.000% 100 100 0 0.022% 0.077% 0.000%Total 88 67 21 0.243% 0.202% 0.707% 2,260,060 449,648 1,810,412 1.201% 0.622% 1.563%

Percent of Population Served 

with At Least One Detection 

> 0.05 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.05 μg/L

Percent of Systems 

with At Least One Detection 

> 0.05 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.05 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A36d. Ethylene dibromide (EDB) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 8 4 4 4.278% 2.878% 8.333% 222,140 37,892 184,248 7.686% 5.168% 8.542%AR 2 2 0 0.441% 0.524% 0.000% 790 790 0 0.032% 0.087% 0.000%AZ 3 2 1 0.322% 0.226% 2.083% 165,250 25,250 140,000 2.729% 0.941% 4.154%CA 33 24 9 1.507% 1.271% 2.980% 1,801,652 737,351 1,064,301 5.225% 5.758% 4.910%CO 2 2 0 0.244% 0.333% 0.000% 920 920 0 0.018% 0.174% 0.000%CT 3 2 1 0.422% 0.297% 2.632% 90,986 13,784 77,202 3.488% 5.017% 3.308%DE 1 1 0 0.301% 0.304% 0.000% 222 222 0 0.031% 0.052% 0.000%FL 2 2 0 0.152% 0.155% 0.000% 2,548 2,548 0 0.015% 0.018% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 135 135 0 0.002% 0.008% 0.000%HI 2 2 0 1.835% 2.062% 0.000% 173,489 173,489 0 13.342% 13.927% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 1 1 0 0.152% 0.159% 0.000% 88 88 0 0.009% 0.012% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 1 0 1 0.071% 0.000% 2.273% 1,600 0 1,600 0.033% 0.000% 0.069%KY 1 0 1 0.412% 0.000% 0.667% 13,084 0 13,084 0.284% 0.000% 0.309%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MDME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 15 12 3 0.635% 0.539% 2.256% 85,845 11,319 74,526 1.265% 0.653% 1.475%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 5 5 0 0.647% 0.656% 0.000% 11,076 11,076 0 0.757% 1.615% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 5 5 0 0.358% 0.368% 0.000% 48,877 48,877 0 0.631% 1.803% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 0 1 0.321% 0.000% 5.000% 56,500 0 56,500 5.832% 0.000% 8.191%NY 1 0 1 0.321% 0.000% 1.299% 12,136 0 12,136 0.939% 0.000% 1.288%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 2 2 0 0.185% 0.214% 0.000% 9,281 9,281 0 0.316% 1.622% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 29 26 3 3.704% 3.596% 5.000% 335,703 69,442 266,261 9.744% 8.554% 10.111%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.260% 0.264% 0.000% 585 585 0 0.021% 0.037% 0.000%WV 1 0 1 0.293% 0.000% 0.690% 4,374 0 4,374 0.319% 0.000% 0.376%WY 1 1 0 0.329% 0.391% 0.000% 100 100 0 0.022% 0.077% 0.000%Total 122 96 26 0.337% 0.289% 0.875% 3,037,381 1,143,149 1,894,232 1.614% 1.581% 1.635%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A37. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 4 mg/L 44,577 493 1.106% 85,996,458 1,341,331 1.560%	
 44,577 2,298 5.155% 85,996,458 6,344,789 7.378%> 4 mg/L 4,023 26 0.646% 147,572,741 1,481,883 1.004%

	
 4,023 146 3.629% 147,572,741 5,108,236 3.462%

> 4 mg/L 48,600 519 1.068% 233,569,199 2,823,214 1.209%	
 48,600 2,444 5.029% 233,569,199 11,453,025 4.903%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A37a. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 901 640 261 32.075% 32.969% 29.885% 0.0001 0.0001 0.0001 0.16 0.15 0.62 1.05 0.7 1.28 1.42 1.3 1.42AL 2,688 1,812 876 58.705% 48.455% 79.909% 0.00059 0.00059 0.00084 0.82 0.66 0.9 1.25 1.31 1.2 10.1 7.76 10.1AR 10,058 6,994 3,064 87.940% 88.805% 85.966% 0.08 0.08 0.2 0.88 0.88 0.88 1.18 1.27 1.09 17 17 3.8AZ 6,648 5,260 1,388 89.576% 88.707% 92.867% 0.005 0.005 0.01 0.5 0.51 0.48 2.47 2.9 1 12.1 12.1 3.3CA 58,593 32,674 25,919 81.648% 81.585% 81.728% 0.00019 0.00019 0.0011 0.42 0.47 0.39 1.54 2.1 0.99 27 27 22CO 4,444 2,421 2,023 83.686% 88.104% 78.398% 0.00344 0.00344 0.03 0.8 0.92 0.68 2.1 2.4 1.6 17.7 17.7 6.1CT 2,597 1,869 728 53.331% 51.471% 58.104% 0.01 0.01 0.01 0.24 0.2 0.81 1 0.72 1.05 7.1 7.1 1.91DE 2,983 2,753 230 56.755% 53.505% 95.652% 0.04 0.04 0.1 0.68 0.62 0.84 1.09 1.08 1.115 20.8 19.4 20.8FL 2,581 2,447 134 81.209% 80.466% 94.776% 0.01 0.01 0.03 0.35 0.32 0.71 0.93 0.93 0.94 6.5 6.5 1.1GA 3,606 2,965 641 74.542% 71.332% 89.392% 0.12 0.12 0.2 0.54 0.44 0.91 1.1 1 1.2 16 16 4.1HI 3,166 3,075 91 22.110% 22.764% 0.000% 0.2 0.2 0.25 0.25 0.64 0.64 2.1 2.1IA 7,062 6,002 1,060 97.890% 97.617% 99.434% 0.1 0.1 0.14 0.96 0.93 1.02 1.24 1.24 1.22 12.02 12.02 1.79ID 2,968 2,664 304 72.776% 72.222% 77.632% 0.0003 0.0003 0.08 0.45 0.45 0.415 1.2 1.2 1.29 16.7 16.7 5.93IL 3,714 3,309 405 96.230% 95.981% 98.272% 0.00016 0.00016 0.00096 0.96 0.96 0.995 1.46 1.51 1.2 25.3 25.3 1.86IN 4,327 3,824 503 86.804% 86.166% 91.650% 0.00014 0.00014 0.05 0.79 0.71 0.93 1.3 1.3 1.2 5.3 5.3 3.42KY 1,824 540 1,284 90.461% 85.000% 92.757% 0.0084 0.07 0.0084 0.97 0.95 0.97 1.24 1.9 1.2 17 4 17MA 3,085 2,073 1,012 59.514% 56.343% 66.008% 0.01 0.01 0.01 0.3 0.24 0.81 1.2 1.25 1.2 29.2 18.1 29.2MD 3,598 2,687 911 70.873% 73.093% 64.325% 0.02 0.02 0.05 0.53 0.4 0.88 1.71 1.98 1.08 4.8 4.8 2.3ME 18,472 9,690 8,782 90.911% 85.717% 96.641% 0.03 0.1 0.03 1.22 1.21 1.23 1.44 1.44 1.44 22 22 3.1MI 26,113 25,390 723 89.871% 89.740% 94.467% 0.05 0.05 0.1 0.3 0.3 0.9 1 1 1.2 21.9 21.9 1.8MN 22,948 22,149 799 98.775% 98.740% 99.750% 0.1 0.1 0.11 1.1 1.1 1.1 1.5 1.5 1.3 24 24 2.9MO 33,121 22,199 10,922 89.937% 86.166% 97.601% 0.01 0.01 0.02 1 1.01 1 1.28 1.31 1.2 31.1 31.1 3.44MT 3,320 2,762 558 84.307% 83.309% 89.247% 0.008 0.008 0.02 0.35 0.3 0.75 1.58 2.05 1.16 10.4 10.4 2.05NC 9,333 7,878 1,455 62.049% 59.216% 77.388% 0.0017 0.0017 0.03 0.31 0.23 0.94 1.17 1.11 1.2 14 14 2.98ND 411 319 92 100.000% 100.000% 100.000% 0.05 0.05 0.34 1 0.76 1.15 1.92 2.41 1.36 5.31 5.31 2.76NE 7,890 7,156 734 98.035% 97.834% 100.000% 0.2 0.2 0.22 0.95 0.94 0.98 1.27 1.3 1.2 28 28 2.2NH 4,683 4,470 213 69.742% 70.940% 44.601% 0.003 0.003 0.1 1.34 1.48 1 3.87 3.89 1.27 9.5 9.5 1.7NJ 11,534 10,136 1,398 38.530% 37.490% 46.066% 0.0017 0.0017 0.007 0.2 0.2 0.14 0.7 0.685 0.73 10 10 1.6NM 4,016 3,556 460 94.846% 95.669% 88.478% 0.01 0.01 0.04 0.61 0.64 0.42 2.84 2.87 2.28 18.6 18.6 6.8NV 3,027 2,064 963 74.133% 75.436% 71.340% 0.02 0.02 0.03 0.505 0.32 0.84 1.61 1.5 1.63 6.4 6.4 3.4NY 6,425 3,790 2,635 67.175% 57.810% 80.645% 0.0001 0.0001 0.0001 0.85 0.6 0.9 1.1 1.1 1.1 21 3 21OH 4,928 4,088 840 80.398% 78.425% 90.000% 0.00014 0.00014 0.00083 0.83 0.62 0.97 1.58 1.69 1.2 3.12 3.12 1.65OK 468 307 161 89.957% 90.554% 88.820% 0.1 0.1 0.1 0.38 0.26 0.77 1.2 1.36 1.1 5.48 5.48 4.66OR 1,327 958 369 33.459% 34.238% 31.436% 0.06 0.08 0.06 0.355 0.3 0.7 1.2 1.2 1.2 5.2 5.2 4.9RI 929 687 242 34.338% 44.687% 4.959% 0.05 0.05 0.21 0.39 0.42 0.25 1.66 1.69 0.56 3.79 3.79 0.69SC 3,743 3,280 463 64.707% 62.134% 82.937% 0.1 0.1 0.1 0.66 0.54 0.78 2.9 3.1 1.08 9.6 9.6 1.9SD 349 333 16 99.140% 99.099% 100.000% 0.00054 0.06 0.00054 0.525 0.5 0.765 1.58 1.605 1.3 9.15 9.15 1.51TN 3,730 1,144 2,586 82.091% 61.014% 91.415% 0.0005 0.0005 0.01 0.96 0.79 0.99 1.2 1.1 1.2 2.8 2.8 2.7TX 18,480 15,003 3,477 90.168% 90.935% 86.856% 0.02 0.03 0.02 0.5 0.55 0.4 2.3 2.6 0.905 14.3 14.3 4.6UT 7,238 5,692 1,546 84.498% 85.190% 81.953% 0.01 0.01 0.05 0.2 0.2 0.2 0.5 0.5 0.3 4.5 4.5 2.8VA 4,439 2,881 1,558 67.650% 57.723% 86.008% 0.01 0.05 0.01 0.96 1.66 0.91 4.65 5.13 1.12 21.4 7.25 21.4VT 1,995 1,690 305 25.113% 23.669% 33.115% 0.008 0.008 0.03 0.33 0.3 1 1.2 1.1 1.22 1.9 1.9 1.67WI 6,918 6,749 169 79.676% 79.301% 94.675% 0.00027 0.00027 0.0019 0.25 0.24 1 1.11 1.1 1.25 38 38 2.2WV 1,348 523 825 77.596% 69.790% 82.545% 0.00006 0.00038 0.00006 0.8 0.32 0.86 1.18 1.18 1.17 3.74 3.74 2.22WY 1,183 928 255 90.955% 93.427% 81.961% 0.0002 0.0016 0.0002 0.5 0.5 0.4 1.5 1.6 1.1 7 7 3.12Total 333,211 249,831 83,380 81.525% 80.310% 85.166% 0.00006 0.0001 0.00006 0.79 0.73 0.86 1.4 1.5 1.27 38 38 29.2

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A37b. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 482 384 98 519,993 208,399 311,594 38.382% 40.104% 31.633% 75.469% 62.684% 84.020%AL 352 279 73 4,701,100 1,463,066 3,238,034 69.602% 63.082% 94.521% 92.277% 79.447% 98.074%AR 453 381 72 2,452,800 909,774 1,543,026 72.627% 75.591% 56.944% 80.493% 90.071% 74.846%AZ 977 929 48 6,129,907 2,759,316 3,370,591 96.520% 96.448% 97.917% 98.787% 97.308% 99.998%CA 3,744 3,220 524 36,402,771 13,574,162 22,828,609 79.915% 80.373% 77.099% 94.888% 94.139% 95.333%CO 822 602 220 4,994,055 529,180 4,464,875 94.404% 95.017% 92.727% 99.506% 97.015% 99.801%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 61.282% 60.212% 92.308% 92.166% 57.627% 97.823%DE 356 353 3 714,769 433,369 281,400 50.562% 50.142% 100.000% 79.464% 66.129% 100.000%FL 1,338 1,312 26 17,215,909 14,969,867 2,246,042 76.532% 76.296% 88.462% 95.723% 95.101% 99.866%GA 1,733 1,617 116 7,466,899 1,574,118 5,892,781 72.706% 71.305% 92.241% 97.780% 91.409% 99.482%HI 112 100 12 1,305,882 1,251,254 54,628 27.679% 31.000% 0.000% 29.594% 30.887% 0.000%IA 968 935 33 2,503,908 1,395,282 1,108,626 97.314% 97.219% 100.000% 99.638% 99.351% 100.000%ID 876 829 47 1,067,405 826,967 240,438 85.502% 86.972% 59.574% 95.118% 95.649% 93.292%IL 1,455 1,356 99 9,318,753 3,124,531 6,194,222 94.433% 94.100% 98.990% 99.668% 99.013% 99.998%IN 1,482 1,433 49 4,949,127 2,588,672 2,360,455 90.486% 90.230% 97.959% 99.233% 98.544% 99.987%KY 242 93 149 4,602,489 375,460 4,227,029 98.760% 96.774% 100.000% 99.996% 99.947% 100.000%MA 678 559 119 8,529,124 1,718,190 6,810,934 74.926% 72.987% 84.034% 81.783% 49.617% 89.897%MD 638 576 62 4,925,647 931,307 3,994,340 75.705% 74.826% 83.871% 98.512% 93.647% 99.646%ME 809 754 55 729,432 292,198 437,234 49.938% 48.143% 74.545% 82.379% 68.234% 91.831%MI 3,086 3,025 61 7,173,058 1,993,202 5,179,856 97.246% 97.190% 100.000% 99.749% 99.098% 100.000%MN 1,468 1,440 28 4,164,508 2,915,017 1,249,491 91.689% 91.597% 96.429% 99.663% 99.521% 99.996%MO 1,423 1,344 79 4,804,863 1,692,282 3,112,581 57.906% 55.506% 98.734% 94.654% 84.893% 99.961%MT 842 783 59 756,961 364,562 392,399 92.993% 92.976% 93.220% 97.437% 95.308% 99.416%NC 2,283 2,144 139 6,973,518 1,708,352 5,265,166 74.376% 73.507% 87.770% 97.260% 93.133% 98.599%ND 217 190 27 563,069 257,844 305,225 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%NE 737 726 11 1,451,390 674,910 776,480 95.387% 95.317% 100.000% 99.342% 98.584% 100.000%NH 1,228 1,187 41 944,942 395,143 549,799 72.638% 73.631% 43.902% 69.744% 69.125% 70.190%NJ 1,372 1,335 37 7,762,979 2,727,033 5,035,946 60.277% 59.476% 89.189% 93.496% 83.582% 98.864%NM 717 678 39 1,673,433 1,406,885 266,548 98.187% 98.083% 100.000% 99.755% 99.709% 100.000%NV 338 317 21 973,605 283,714 689,891 89.941% 90.536% 80.952% 97.910% 98.098% 97.833%NY 1,600 1,357 243 11,225,138 1,229,838 9,995,300 52.063% 50.111% 62.963% 91.487% 48.247% 96.808%OH 1,934 1,808 126 10,225,777 3,129,983 7,095,794 83.816% 83.020% 95.238% 97.246% 91.179% 99.921%OK 197 165 32 782,508 262,331 520,177 82.741% 88.485% 53.125% 95.361% 96.150% 94.963%OR 730 606 124 2,813,374 486,528 2,326,846 31.096% 31.023% 31.452% 66.219% 55.418% 68.478%RI 143 134 9 913,584 173,606 739,978 59.441% 61.940% 22.222% 20.095% 90.087% 3.674%SC 823 758 65 3,462,992 804,465 2,658,527 67.315% 65.303% 90.769% 95.858% 82.796% 99.811%SD 207 199 8 194,476 121,093 73,383 99.034% 98.995% 100.000% 99.919% 99.870% 100.000%TN 350 161 189 5,683,572 1,460,816 4,222,756 85.429% 75.776% 93.651% 85.563% 49.295% 98.109%TX 4,935 4,592 343 25,112,657 9,327,672 15,784,985 95.096% 95.035% 95.918% 99.546% 99.103% 99.807%UT 506 457 49 2,543,652 1,686,017 857,635 96.047% 95.842% 97.959% 99.367% 99.651% 98.808%VA 1,617 1,440 177 5,729,159 647,279 5,081,880 51.082% 48.333% 73.446% 94.094% 58.539% 98.623%VT 597 555 42 490,319 226,551 263,768 38.191% 37.477% 47.619% 61.858% 40.745% 79.992%WI 1,805 1,785 20 4,041,330 2,349,586 1,691,744 91.025% 90.924% 100.000% 98.315% 97.103% 100.000%WV 454 293 161 1,416,005 235,215 1,180,790 78.194% 70.648% 91.925% 97.416% 89.603% 98.972%WY 304 255 49 446,184 129,168 317,016 95.066% 96.078% 89.796% 95.068% 97.385% 94.124%Total 48,600 44,577 4,023 233,569,199 85,996,458 147,572,741 79.276% 78.991% 82.426% 94.425% 90.508% 96.708%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A37c. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 5 4 1 1.420% 1.434% 1.370% 55,123 32,873 22,250 1.173% 2.247% 0.687%AR 8 8 0 1.766% 2.100% 0.000% 37,108 37,108 0 1.513% 4.079% 0.000%AZ 38 38 0 3.889% 4.090% 0.000% 61,306 61,306 0 1.000% 2.222% 0.000%CA 39 32 7 1.042% 0.994% 1.336% 1,347,272 495,658 851,614 3.701% 3.651% 3.730%CO 14 12 2 1.703% 1.993% 0.909% 5,968 5,118 850 0.120% 0.967% 0.019%CT 3 3 0 0.256% 0.265% 0.000% 13,202 13,202 0 0.486% 3.454% 0.000%DE 5 3 2 1.404% 0.850% 66.667% 231,394 55,264 176,130 32.373% 12.752% 62.591%FL 3 3 0 0.224% 0.229% 0.000% 435 435 0 0.003% 0.003% 0.000%GA 10 9 1 0.577% 0.557% 0.862% 26,233 24,106 2,127 0.351% 1.531% 0.036%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 4 4 0 0.413% 0.428% 0.000% 2,277 2,277 0 0.091% 0.163% 0.000%ID 9 8 1 1.027% 0.965% 2.128% 1,551 1,411 140 0.145% 0.171% 0.058%IL 17 17 0 1.168% 1.254% 0.000% 64,306 64,306 0 0.690% 2.058% 0.000%IN 7 7 0 0.472% 0.488% 0.000% 3,099 3,099 0 0.063% 0.120% 0.000%KY 3 0 3 1.240% 0.000% 2.013% 27,507 0 27,507 0.598% 0.000% 0.651%MA 4 3 1 0.590% 0.537% 0.840% 84,631 40,870 43,761 0.992% 2.379% 0.643%MD 3 3 0 0.470% 0.521% 0.000% 5,526 5,526 0 0.112% 0.593% 0.000%ME 7 7 0 0.865% 0.928% 0.000% 5,959 5,959 0 0.817% 2.039% 0.000%MI 9 9 0 0.292% 0.298% 0.000% 26,119 26,119 0 0.364% 1.310% 0.000%MN 40 40 0 2.725% 2.778% 0.000% 32,203 32,203 0 0.773% 1.105% 0.000%MO 14 14 0 0.984% 1.042% 0.000% 52,774 52,774 0 1.098% 3.119% 0.000%MT 15 15 0 1.781% 1.916% 0.000% 5,028 5,028 0 0.664% 1.379% 0.000%NC 7 7 0 0.307% 0.326% 0.000% 8,910 8,910 0 0.128% 0.522% 0.000%ND 2 2 0 0.922% 1.053% 0.000% 196 196 0 0.035% 0.076% 0.000%NE 10 10 0 1.357% 1.377% 0.000% 30,445 30,445 0 2.098% 4.511% 0.000%NH 32 32 0 2.606% 2.696% 0.000% 6,786 6,786 0 0.718% 1.717% 0.000%NJ 4 4 0 0.292% 0.300% 0.000% 1,975 1,975 0 0.025% 0.072% 0.000%NM 20 19 1 2.789% 2.802% 2.564% 68,250 68,017 233 4.078% 4.835% 0.087%NV 2 2 0 0.592% 0.631% 0.000% 1,160 1,160 0 0.119% 0.409% 0.000%NY 3 0 3 0.188% 0.000% 1.235% 82,977 0 82,977 0.739% 0.000% 0.830%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 2 1 1 1.015% 0.606% 3.125% 125,520 89 125,431 16.041% 0.034% 24.113%OR 4 3 1 0.548% 0.495% 0.806% 10,705 755 9,950 0.381% 0.155% 0.428%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 11 11 0 1.337% 1.451% 0.000% 40,158 40,158 0 1.160% 4.992% 0.000%SD 2 2 0 0.966% 1.005% 0.000% 1,707 1,707 0 0.878% 1.410% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 83 82 1 1.682% 1.786% 0.292% 226,143 127,998 98,145 0.901% 1.372% 0.622%UT 2 2 0 0.395% 0.438% 0.000% 6,938 6,938 0 0.273% 0.412% 0.000%VA 61 60 1 3.772% 4.167% 0.565% 66,614 25,846 40,768 1.163% 3.993% 0.802%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 12 12 0 0.665% 0.672% 0.000% 27,370 27,370 0 0.677% 1.165% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 5 5 0 1.645% 1.961% 0.000% 28,339 28,339 0 6.351% 21.940% 0.000%Total 519 493 26 1.068% 1.106% 0.646% 2,823,214 1,341,331 1,481,883 1.209% 1.560% 1.004%

Percent of Population Served 

with At Least One Detection 

> 4 mg/L

State

Number of Systems 

with At Least One Detection 

> 4 mg/L

Percent of Systems 

with At Least One Detection 

> 4 mg/L

Population Served by Systems 

with At Least One Detection 

> 4 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A37d. Fluoride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 25 21 4 7.102% 7.527% 5.479% 308,003 181,785 126,218 6.552% 12.425% 3.898%AR 25 23 2 5.519% 6.037% 2.778% 134,993 120,165 14,828 5.504% 13.208% 0.961%AZ 140 133 7 14.330% 14.316% 14.583% 1,842,086 1,171,217 670,869 30.051% 42.446% 19.904%CA 130 111 19 3.472% 3.447% 3.626% 2,242,341 937,450 1,304,891 6.160% 6.906% 5.716%CO 148 124 24 18.005% 20.598% 10.909% 374,552 171,475 203,077 7.500% 32.404% 4.548%CT 10 10 0 0.855% 0.884% 0.000% 13,596 13,596 0 0.501% 3.557% 0.000%DE 6 4 2 1.685% 1.133% 66.667% 233,794 57,664 176,130 32.709% 13.306% 62.591%FL 16 16 0 1.196% 1.220% 0.000% 11,964 11,964 0 0.069% 0.080% 0.000%GA 28 25 3 1.616% 1.546% 2.586% 88,553 75,610 12,943 1.186% 4.803% 0.220%HI 1 1 0 0.893% 1.000% 0.000% 260 260 0 0.020% 0.021% 0.000%IA 48 48 0 4.959% 5.134% 0.000% 59,748 59,748 0 2.386% 4.282% 0.000%ID 26 24 2 2.968% 2.895% 4.255% 235,508 49,368 186,140 22.064% 5.970% 77.417%IL 74 74 0 5.086% 5.457% 0.000% 196,428 196,428 0 2.108% 6.287% 0.000%IN 68 65 3 4.588% 4.536% 6.122% 122,357 89,366 32,991 2.472% 3.452% 1.398%KY 17 9 8 7.025% 9.677% 5.369% 121,981 5,026 116,955 2.650% 1.339% 2.767%MA 12 8 4 1.770% 1.431% 3.361% 190,572 54,700 135,872 2.234% 3.184% 1.995%MD 20 19 1 3.135% 3.299% 1.613% 105,414 51,414 54,000 2.140% 5.521% 1.352%ME 33 27 6 4.079% 3.581% 10.909% 93,474 33,566 59,908 12.815% 11.487% 13.702%MI 35 35 0 1.134% 1.157% 0.000% 83,524 83,524 0 1.164% 4.190% 0.000%MN 230 227 3 15.668% 15.764% 10.714% 290,666 280,872 9,794 6.980% 9.635% 0.784%MO 76 69 7 5.341% 5.134% 8.861% 266,367 189,781 76,586 5.544% 11.215% 2.461%MT 46 45 1 5.463% 5.747% 1.695% 11,412 10,612 800 1.508% 2.911% 0.204%NC 62 57 5 2.716% 2.659% 3.597% 414,925 299,726 115,199 5.950% 17.545% 2.188%ND 18 17 1 8.295% 8.947% 3.704% 16,094 14,311 1,783 2.858% 5.550% 0.584%NE 28 27 1 3.799% 3.719% 9.091% 66,224 57,659 8,565 4.563% 8.543% 1.103%NH 115 115 0 9.365% 9.688% 0.000% 28,180 28,180 0 2.982% 7.132% 0.000%NJ 15 15 0 1.093% 1.124% 0.000% 115,187 115,187 0 1.484% 4.224% 0.000%NM 76 75 1 10.600% 11.062% 2.564% 125,166 124,933 233 7.480% 8.880% 0.087%NV 15 13 2 4.438% 4.101% 9.524% 77,147 20,347 56,800 7.924% 7.172% 8.233%NY 15 10 5 0.938% 0.737% 2.058% 113,850 8,073 105,777 1.014% 0.656% 1.058%OH 61 61 0 3.154% 3.374% 0.000% 49,780 49,780 0 0.487% 1.590% 0.000%OK 10 9 1 5.076% 5.455% 3.125% 140,651 15,220 125,431 17.974% 5.802% 24.113%OR 13 11 2 1.781% 1.815% 1.613% 37,800 11,020 26,780 1.344% 2.265% 1.151%RI 5 5 0 3.497% 3.731% 0.000% 1,357 1,357 0 0.149% 0.782% 0.000%SC 49 49 0 5.954% 6.464% 0.000% 83,020 83,020 0 2.397% 10.320% 0.000%SD 14 14 0 6.763% 7.035% 0.000% 7,593 7,593 0 3.904% 6.270% 0.000%TN 6 1 5 1.714% 0.621% 2.646% 48,732 2,547 46,185 0.857% 0.174% 1.094%TX 464 449 15 9.402% 9.778% 4.373% 2,347,413 1,286,745 1,060,668 9.348% 13.795% 6.719%UT 9 7 2 1.779% 1.532% 4.082% 106,327 23,937 82,390 4.180% 1.420% 9.607%VA 184 179 5 11.379% 12.431% 2.825% 296,424 121,290 175,134 5.174% 18.738% 3.446%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 41 40 1 2.271% 2.241% 5.000% 294,702 191,684 103,018 7.292% 8.158% 6.089%WV 4 2 2 0.881% 0.683% 1.242% 8,816 595 8,221 0.623% 0.253% 0.696%WY 26 24 2 8.553% 9.412% 4.082% 46,044 35,994 10,050 10.320% 27.866% 3.170%Total 2,444 2,298 146 5.029% 5.155% 3.629% 11,453,025 6,344,789 5,108,236 4.903% 7.378% 3.462%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A38. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 700 μg/L 14,974 0 0.000% 46,311,603 0 0.000%

	
 14,974 1 0.007% 46,311,603 40 0.000%

> 700 μg/L 1,377 0 0.000% 69,964,408 0 0.000%

	
 1,377 1 0.073% 69,964,408 48,800 0.070%> 700 μg/L }* 0 0.000% 116,276,011 0 0.000%

	
 }* 2 0.012% 116,276,011 48,840 0.042%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A38a. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 28 10 18 0.000% 0.000% 0.000%AL ' 376 128 0.000% 0.000% 0.000%AR * 1,290  0.000% 0.000% 0.000%AZ * 4,123 980 0.118% 0.146% 0.000% 6 6 8 8    CA 10,882 *}= * 0.018% 0.017% 0.020%   66 '  66 66  66 66  66CO 430 367 63 0.000% 0.000% 0.000%CT 1,288 980 308 0.000% 0.000% 0.000%DE 3 0 3 0.000% 0.000% 0.000%FL * *+ } 0.766% 0.788% 0.000%   10 10 100 100 700 700GA 1,421 1,348 73 0.070% 0.074% 0.000% 290 290 290 290 290 290 290 290HI 1,694 1,649 ' 0.000% 0.000% 0.000%IA 47 30 17 0.000% 0.000% 0.000%ID * 1,038 214 0.000% 0.000% 0.000%IL 903 747 } 0.000% 0.000% 0.000%IN 2,178 2,041 137 0.000% 0.000% 0.000%KY 1,710 440 1,270 0.468% 0.000% 0.630% 2.6 2.6      MA 7 2  0.000% 0.000% 0.000%MD 167 9 + 0.000% 0.000% 0.000%ME 1 1 0 0.000% 0.000% 0.000%MI 29 17 12 0.000% 0.000% 0.000%MN '*' 4,439  0.000% 0.000% 0.000%MOMT 923 833 90 0.000% 0.000% 0.000%NCND = 38 21 0.000% 0.000% 0.000%NE 1,293 1,273 20 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 1 1 0 0.000% 0.000% 0.000%NM 4,247 3,996  0.000% 0.000% 0.000%NV *' * 391 =| 0.087% | 6  6 6  6   6   6NY 82 8 74 0.000% 0.000% 0.000%OH  382  0.000% 0.000% 0.000%OK 3 3 0 0.000% 0.000% 0.000%OR 2,082 1,600 482 0.048% 0.063% 0.000% 30 30 30 30 30 30 30 30RI 4 4 0 0.000% 0.000% 0.000%SC 2,824 2,462 362 | 0.041% 0.000% 6 6 6 6 6 6 6 6SD 949 840 109 0.000% 0.000% 0.000%TN 83 14 69 0.000% 0.000% 0.000%TXUT 40 30 10 | 3.333% 0.000% 10 10 10 10 10 10 10 10VA 3 1 2 0.000% 0.000% 0.000%VT 12 11 1 0.000% 0.000% 0.000%WI 3,164 3,073 91 0.000% 0.000% 0.000%WV  3 2 0.000% 0.000% 0.000%WY  34 23 0.000% 0.000% 0.000%Total +*' '}*= *+ 0.070% 0.064% =| 2.6  2.6 10 10 10 = = 66 700 700 

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A38b. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 6 4 2 *' 13,281 8,964 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 172 127 ' 2,709,297 =}*= **++ 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR '' 382 72 *'*'+ 910,322 *'*} 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 903 +} 47 *=*= *+=*++' 3,368,091 0.332% | 0.000% 0.416% =| 0.000%CA * 779 236 32,642,273 *'* 21,216,721 0.197% 0.128% 0.424% 0.011% 0.002% 0.016%CO 220 +  2,360,023 223,603 2,136,420 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT }' 608 37 *+*} +*=} 2,327,267 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 1 0 1 140,000 0 140,000 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,307 1,286 21 16,746,341 '**} 2,239,176 0.918% 0.933% 0.000% 16.638% 19.206% 0.000%GA 293 280 13 987,804 =+*' }+=* 0.341% | 0.000% '| | 0.000%HI 109 97 12 1,300,349 *'* '*}+ 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 3 2 1 162,167 * 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID }} = 27 +*+ }'*}+} 217,892 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL '' 389 } *}*' 921,320 *+*' 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN *' 1,216 38 '*=*} *+=*=} 2,219,719 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 243 93  4,612,320 *'} 4,236,860 2.469% 0.000% 4.000% 8.494% 0.000% 9.247%MA 3 2 1 66,881 29,266 *} 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MD 16 6 10 *+}* 2,940 *+* 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ME 1 1 0 320 320 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI  8 7 **} *++ *}*+= 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,282 * 29 3,931,436 *}+*= 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MOMT }  48 }+*' 309,762 *== 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NCND 28 22 6 '*}} 40,636 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 634 631 3 1,110,676 *} *}} 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 ='*' =*= '=*== 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 1 1 0 2,061 2,061 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 691 } 36 *}=*= 1,397,074 262,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 289 268 21 960,377 270,486 689,891 0.692% 0.373% 4.762% 34.910% 0.333% 48.467%NY 16 7 9 }*== 17,742 499,248 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 268 189 79 }*'}* 482,792 *=+*' 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OK 3 3 0 2,634 2,634 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OR 1,097 947  *='*' *' *}'* 0.091% 0.106% 0.000% | | 0.000%RI 4 4 0 +* +* 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC } 706 = *'*=+ ==* 2,626,783 0.131% 0.142% 0.000% 0.004% | 0.000%SD 261 240 21 622,272 263,101 =* 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 27 8 19 **== 144,998 1,010,931 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TXUT 12 8 4 *' }* =*} 8.333% | 0.000% 0.009% 0.022% 0.000%VA 2 1 1 *} } *} 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 12 11 1 76,640 7,717 68,923 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WI 1,407 1,387 20 3,883,613 2,191,869 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV  3 2 *' +*} *+ 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WY  17 8 190,439 14,860 *= 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total }* 14,974 1,377 116,276,011 46,311,603 69,964,408 0.177% 0.140% +| 3.047% 6.074% 1.043%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A38c. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NCND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 700 μg/L

State

Number of Systems 

with At Least One Detection 

> 700 μg/L

Percent of Systems 

with At Least One Detection 

> 700 μg/L

Population Served by Systems 

with At Least One Detection 

> 700 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A38d. Glyphosate – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.077% 0.078% 0.000% 40 40 0 0.000% 0.0003% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.412% 0.000% 0.667% 48,800 0 48,800 +| 0.000% |MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NCND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 1 1 0.012% 0.007% 0.073% 48,840 40 48,800 0.042% 0.0001% 0.070%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A39. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.4 μg/L 29,965 1 0.003% 67,922,151 325 0.000%

	
 29,965 3 0.010% 67,922,151 5,615 0.008%	
 29,965 207 0.691% 67,922,151 470,220 0.692%> 0.4 μg/L 3,055 1 0.033% 116,521,633 4,374 0.004%	
 3,055 4 0.131% 116,521,633 262,286 0.225%	
 3,055 27 0.884% 116,521,633 3,435,360 2.948%

> 0.4 μg/L 33,020 2 0.006% 184,443,784 4,699 0.003%	
 33,020 7 0.021% 184,443,784 267,901 0.145%	
 33,020 234 0.709% 184,443,784 3,905,580 2.117%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A39a. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 103 53 50 0.000% 0.000% 0.000%AL 525 394 131 0.000% 0.000% 0.000%AR 1,664 1,423 241 0.000% 0.000% 0.000%AZ 7,207 5,637 1,570 0.014% 0.000% 0.064% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2CA 13,241 7,880 5,361 0.045% 0.063% 0.019% 0.004 0.004 0.04 0.01 0.01 0.04 0.04 0.01 0.04 0.04 0.01 0.04CO 2,533 1,829 704 0.000% 0.000% 0.000%CT 1,331 1,013 318 0.000% 0.000% 0.000%DE 758 729 29 0.264% 0.137% 3.448% 0.1 0.18 0.1 0.14 0.18 0.1 0.18 0.18 0.1 0.18 0.18 0.1FL 2,393 2,326 67 0.460% 0.473% 0.000% 0.001 0.001 0.001 0.001 0.001 0.001 0.008 0.008GA 1,482 1,402 80 0.000% 0.000% 0.000%HI 1,947 1,850 97 0.000% 0.000% 0.000%IA 146 131 15 0.000% 0.000% 0.000%ID 1,737 1,479 258 0.000% 0.000% 0.000%IL 4,686 3,945 741 0.043% 0.051% 0.000% 0.02 0.02 0.035 0.035 0.05 0.05 0.05 0.05IN 2,241 2,077 164 0.000% 0.000% 0.000%KY 1,746 447 1,299 0.401% 0.224% 0.462% 0.001 0.1 0.001 0.1 0.1 0.12 0.2 0.1 0.2 0.2 0.1 0.2MA 3,025 2,238 787 0.066% 0.000% 0.254% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01MD 2,748 1,729 1,019 0.291% 0.058% 0.687% 0.01 0.04 0.01 0.015 0.04 0.01 0.12 0.04 0.12 0.12 0.04 0.12ME 456 391 65 0.000% 0.000% 0.000%MI 6,875 6,423 452 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 5,559 4,691 868 0.000% 0.000% 0.000%MT 2,958 2,656 302 0.000% 0.000% 0.000%NC 13,608 12,473 1,135 0.015% 0.008% 0.088% 0.14 0.39 0.14 0.265 0.39 0.14 0.39 0.39 0.14 0.39 0.39 0.14ND 403 337 66 0.496% 0.593% 0.000% 0.06 0.06 0.065 0.065 0.07 0.07 0.07 0.07NE 4,480 4,131 349 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 41 33 8 0.000% 0.000% 0.000%NM 4,367 4,115 252 0.000% 0.000% 0.000%NV 1,638 1,200 438 0.000% 0.000% 0.000%NY 2,942 2,203 739 0.000% 0.000% 0.000%OH 235 97 138 0.000% 0.000% 0.000%OKOR 2,054 1,571 483 0.000% 0.000% 0.000%RI 601 414 187 0.000% 0.000% 0.000%SC 2,928 2,537 391 18.340% 19.117% 13.299% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1SD 953 844 109 0.000% 0.000% 0.000%TN 62 12 50 0.000% 0.000% 0.000%TX 11,038 5,279 5,759 0.000% 0.000% 0.000%UT 7,115 5,927 1,188 0.000% 0.000% 0.000%VA 503 178 325 0.000% 0.000% 0.000%VT 1,321 1,118 203 0.076% 0.089% 0.000% 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08WI 3,193 3,100 93 0.063% 0.065% 0.000% 0.17 0.17 0.185 0.185 0.2 0.2 0.2 0.2WV 645 336 309 2.171% 2.679% 1.618% 0.0045 0.0045 0.0077 0.0077 0.0077 0.04 0.5 0.5 0.5 0.5 0.5 0.5WY 1,284 964 320 0.000% 0.000% 0.000%Total 133,726 106,106 27,620 0.446% 0.491% 0.275% 0.001 0.001 0.001 0.1 0.1 0.1 0.1 0.1 0.12 0.5 0.5 0.5

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A39b. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 15 10 5 246,261 14,306 231,955 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 176 131 45 2,738,380 625,792 2,112,588 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 450 379 71 2,447,627 905,863 1,541,764 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 949 901 48 6,081,248 2,710,657 3,370,591 0.105% 0.000% 2.083% 0.027% 0.000% 0.049%CA 1,628 1,335 293 33,775,878 12,089,748 21,686,130 0.184% 0.150% 0.341% 0.121% 0.327% 0.007%CO 808 589 219 4,990,621 523,712 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 656 618 38 2,595,293 261,406 2,333,887 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 201 198 3 628,982 347,582 281,400 0.995% 0.505% 33.333% 22.284% 0.047% 49.751%FL 1,314 1,293 21 16,792,349 14,553,173 2,239,176 0.381% 0.387% 0.000% 15.508% 17.894% 0.000%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 100 88 12 1,256,886 1,202,258 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 95 93 2 238,892 99,507 139,385 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 723 676 47 978,700 742,024 236,676 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,371 1,267 104 9,186,700 2,986,303 6,200,397 0.146% 0.158% 0.000% 1.695% 5.214% 0.000%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 2.058% 1.075% 2.667% 7.279% 1.749% 7.769%MA 644 527 117 8,485,298 1,682,916 6,802,382 0.155% 0.000% 0.855% 0.516% 0.000% 0.643%MD 862 794 68 4,906,096 907,989 3,998,107 0.464% 0.126% 4.412% 69.869% 0.039% 85.728%ME 269 241 28 510,420 134,500 375,920 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,935 2,874 61 7,227,231 2,047,375 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,471 1,395 76 2,644,644 1,700,183 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 812 752 60 753,149 360,480 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.085% 0.045% 0.730% 1.165% 0.221% 1.483%ND 208 181 27 559,142 253,917 305,225 0.962% 1.105% 0.000% 0.196% 0.432% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 36 30 6 1,444,605 143,223 1,301,382 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 695 659 36 1,662,962 1,400,064 262,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 291 270 21 960,972 271,081 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,347 1,116 231 4,924,771 981,494 3,943,277 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 48 36 12 3,617,992 147,360 3,470,632 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,084 934 150 2,937,104 572,354 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 86 77 9 902,061 162,083 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 770 711 59 3,427,270 800,487 2,626,783 28.701% 28.270% 33.898% 49.559% 56.446% 47.461%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 12 6 6 655,614 145,112 510,502 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 427 390 37 2,500,736 1,667,550 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 442 409 33 432,910 181,746 251,164 0.226% 0.244% 0.000% 0.071% 0.169% 0.000%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.142% 0.144% 0.000% 0.193% 0.342% 0.000%WV 343 196 147 1,368,815 204,156 1,164,659 3.499% 4.592% 2.041% 0.829% 0.971% 0.804%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 33,020 29,965 3,055 184,443,784 67,922,151 116,521,633 0.796% 0.761% 1.146% 4.635% 4.819% 4.528%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A39c. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.583% 0.510% 0.680% 4,699 325 4,374 0.343% 0.159% 0.376%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 1 1 0.006% 0.003% 0.033% 4,699 325 4,374 0.003% 0.000% 0.004%

Percent of Population Served 

with At Least One Detection 

> 0.4 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.4 μg/L

Percent of Systems 

with At Least One Detection 

> 0.4 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.4 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A39d. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 0 1 0.105% 0.000% 2.083% 1,650 0 1,650 0.027% 0.000% 0.049%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.412% 0.000% 0.667% 254,462 0 254,462 5.517% 0.000% 6.006%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 3,832 3,832 0 0.056% 0.221% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.071% 0.072% 0.000% 1,458 1,458 0 0.038% 0.067% 0.000%WV 3 1 2 0.875% 0.510% 1.361% 6,499 325 6,174 0.475% 0.159% 0.530%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 7 3 4 0.021% 0.010% 0.131% 267,901 5,615 262,286 0.145% 0.008% 0.225%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A39e. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 0 1 0.105% 0.000% 2.083% 1,650 0 1,650 0.027% 0.000% 0.049%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 2 1 1 0.995% 0.505% 33.333% 140,165 165 140,000 22.284% 0.047% 49.751%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 2 1 1 0.823% 1.075% 0.667% 261,029 6,567 254,462 5.659% 1.749% 6.006%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 0 1 0.116% 0.000% 1.471% 1,710,000 0 1,710,000 34.855% 0.000% 42.770%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 1 1 0.085% 0.045% 0.730% 80,218 3,832 76,386 1.165% 0.221% 1.483%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 221 201 20 28.701% 28.270% 33.898% 1,698,527 451,839 1,246,688 49.559% 56.446% 47.461%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.142% 0.144% 0.000% 7,492 7,492 0 0.193% 0.342% 0.000%WV 3 1 2 0.875% 0.510% 1.361% 6,499 325 6,174 0.475% 0.159% 0.530%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 234 207 27 0.709% 0.691% 0.884% 3,905,580 470,220 3,435,360 2.117% 0.692% 2.948%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A40. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.2 μg/L 29,961 5 0.017% 67,983,066 14,973 0.022%	
 29,961 11 0.037% 67,983,066 22,458 0.033%

> 0.2 μg/L 3,054 1 0.033% 116,494,709 4,374 0.004%

	
 3,054 4 0.131% 116,494,709 439,554 0.377%

> 0.2 μg/L 33,015 6 0.018% 184,477,775 19,347 0.010%	
 33,015 15 0.045% 184,477,775 462,012 0.250%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A40a. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 102 53 49 0.000% 0.000% 0.000%AL 537 404 133 0.372% 0.000% 1.504% 0.02 0.02 0.025 0.025 0.03 0.03 0.03 0.03AR 1,664 1,423 241 0.000% 0.000% 0.000%AZ 7,233 5,668 1,565 0.069% 0.088% 0.000% 0.08 0.08 0.08 0.08 0.1 0.1 0.1 0.1CA 14,079 8,153 5,926 0.000% 0.000% 0.000%CO 2,532 1,827 705 0.000% 0.000% 0.000%CT 1,332 1,014 318 0.000% 0.000% 0.000%DE 758 729 29 0.132% 0.000% 3.448% 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05FL 2,400 2,333 67 0.458% 0.471% 0.000% 0.006 0.006 0.01 0.01 0.01 0.01 0.01 0.01GA 1,482 1,402 80 0.067% 0.071% 0.000% 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12HI 2,101 2,004 97 0.048% 0.050% 0.000% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01IA 147 131 16 0.000% 0.000% 0.000%ID 1,743 1,485 258 0.000% 0.000% 0.000%IL 4,692 3,951 741 0.171% 0.127% 0.405% 0.003 0.003 0.03 0.03 0.02 0.03 0.08 0.08 0.04 0.08 0.08 0.04IN 2,238 2,074 164 0.000% 0.000% 0.000%KY 1,735 444 1,291 0.288% 0.000% 0.387% 0.001 0.001 0.02 0.02 0.2 0.2 0.2 0.2MA 3,025 2,237 788 0.165% 0.089% 0.381% 0.01 0.02 0.01 0.02 1.01 0.01 2 2 0.11 2 2 0.11MD 2,746 1,728 1,018 0.036% 0.058% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1ME 378 339 39 0.000% 0.000% 0.000%MI 6,874 6,422 452 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 5,559 4,691 868 0.000% 0.000% 0.000%MT 3,005 2,697 308 0.000% 0.000% 0.000%NC 13,605 12,470 1,135 0.875% 0.954% 0.000% 0.009 0.009 0.03 0.03 0.06 0.06 0.41 0.41ND 410 344 66 0.488% 0.581% 0.000% 0.05 0.05 0.07 0.07 0.09 0.09 0.09 0.09NE 4,480 4,131 349 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 41 33 8 0.000% 0.000% 0.000%NM 4,356 4,106 250 0.000% 0.000% 0.000%NV 1,640 1,201 439 0.000% 0.000% 0.000%NY 2,942 2,202 740 0.000% 0.000% 0.000%OH 236 97 139 0.000% 0.000% 0.000%OKOR 2,056 1,573 483 0.000% 0.000% 0.000%RI 601 414 187 0.166% 0.242% 0.000% 0.005 0.005 0.005 0.005 0.005 0.005 0.005 0.005SC 2,924 2,532 392 0.000% 0.000% 0.000%SD 953 844 109 0.000% 0.000% 0.000%TN 62 12 50 0.000% 0.000% 0.000%TX 11,038 5,279 5,759 0.000% 0.000% 0.000%UT 7,115 5,927 1,188 0.000% 0.000% 0.000%VA 503 178 325 0.199% 0.000% 0.308% 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05VT 1,323 1,120 203 0.076% 0.089% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1WI 3,183 3,090 93 0.000% 0.000% 0.000%WV 645 336 309 2.171% 2.679% 1.618% 0.003 0.003 0.0042 0.0042 0.0042 0.02 0.5 0.5 0.5 0.5 0.5 0.5WY 1,279 959 320 0.000% 0.000% 0.000%Total 134,708 106,551 28,157 0.132% 0.148% 0.071% 0.001 0.003 0.001 0.03 0.03 0.03 0.1 0.09 0.2 2 2 0.5

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A40b. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 15 10 5 246,261 14,306 231,955 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 177 132 45 2,757,325 644,737 2,112,588 0.565% 0.000% 2.222% 1.416% 0.000% 1.848%AR 450 379 71 2,447,627 905,863 1,541,764 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 949 901 48 6,081,248 2,710,657 3,370,591 0.211% 0.222% 0.000% 0.837% 1.877% 0.000%CA 1,629 1,335 294 33,810,974 12,089,844 21,721,130 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CO 808 589 219 4,990,621 523,712 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 657 619 38 2,595,377 261,490 2,333,887 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 201 198 3 628,982 347,582 281,400 0.498% 0.000% 33.333% 16.737% 0.000% 37.409%FL 1,314 1,293 21 16,793,186 14,554,010 2,239,176 0.457% 0.464% 0.000% 17.386% 20.061% 0.000%GA 297 283 14 997,274 305,252 692,022 0.337% 0.353% 0.000% 0.003% 0.010% 0.000%HI 112 100 12 1,305,882 1,251,254 54,628 0.893% 1.000% 0.000% 4.860% 5.072% 0.000%IA 95 93 2 238,892 99,507 139,385 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 724 677 47 979,025 742,349 236,676 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,371 1,267 104 9,186,700 2,986,303 6,200,397 0.584% 0.395% 2.885% 0.637% 0.303% 0.798%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 1.646% 0.000% 2.667% 7.137% 0.000% 7.769%MA 644 527 117 8,485,298 1,682,916 6,802,382 0.621% 0.380% 1.709% 2.967% 1.726% 3.274%MD 861 793 68 4,906,066 907,959 3,998,107 0.116% 0.126% 0.000% 0.124% 0.668% 0.000%ME 248 223 25 497,016 126,396 370,620 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,934 2,873 61 7,227,105 2,047,249 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,471 1,395 76 2,644,644 1,700,183 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 1.142% 1.212% 0.000% 0.737% 2.927% 0.000%ND 209 182 27 559,198 253,973 305,225 0.957% 1.099% 0.000% 0.196% 0.432% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 36 30 6 1,444,605 143,223 1,301,382 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 695 659 36 1,662,962 1,400,064 262,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 291 270 21 960,972 271,081 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,347 1,116 231 4,924,771 981,494 3,943,277 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 49 36 13 3,561,368 147,360 3,414,008 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,084 934 150 2,937,104 572,354 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 86 77 9 902,061 162,083 739,978 1.163% 1.299% 0.000% 0.014% 0.080% 0.000%SC 769 710 59 3,426,996 800,213 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 12 6 6 655,614 145,112 510,502 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 427 390 37 2,500,736 1,667,550 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.549% 0.000% 0.901% 0.379% 0.000% 0.384%VT 442 409 33 432,910 181,746 251,164 0.226% 0.244% 0.000% 0.071% 0.169% 0.000%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 343 196 147 1,368,815 204,156 1,164,659 3.499% 4.592% 2.041% 0.829% 0.971% 0.804%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 33,015 29,961 3,054 184,477,775 67,983,066 116,494,709 0.221% 0.194% 0.491% 2.112% 4.608% 0.656%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A40c. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 1 1 0 0.155% 0.190% 0.000% 13,849 13,849 0 0.163% 0.823% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 3 0 0.127% 0.135% 0.000% 799 799 0 0.012% 0.046% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.583% 0.510% 0.680% 4,699 325 4,374 0.343% 0.159% 0.376%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 6 5 1 0.018% 0.017% 0.033% 19,347 14,973 4,374 0.010% 0.022% 0.004%

Percent of Population Served 

with At Least One Detection 

> 0.2 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.2 μg/L

Percent of Systems 

with At Least One Detection 

> 0.2 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.2 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A40d. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.105% 0.111% 0.000% 245 245 0 0.004% 0.009% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 1 0 0.337% 0.353% 0.000% 31 31 0 0.003% 0.010% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.412% 0.000% 0.667% 254,462 0 254,462 5.517% 0.000% 6.006%MA 2 1 1 0.311% 0.190% 0.855% 192,767 13,849 178,918 2.272% 0.823% 2.630%MD 1 1 0 0.116% 0.126% 0.000% 6,062 6,062 0 0.124% 0.668% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 5 5 0 0.211% 0.224% 0.000% 1,638 1,638 0 0.024% 0.094% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 1 1 0 0.226% 0.244% 0.000% 308 308 0 0.071% 0.169% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 3 1 2 0.875% 0.510% 1.361% 6,499 325 6,174 0.475% 0.159% 0.530%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 15 11 4 0.045% 0.037% 0.131% 462,012 22,458 439,554 0.250% 0.033% 0.377%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A41. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 1 μg/L 29,793 3 0.010% 67,957,193 2,273 0.003%

	
 29,793 12 0.040% 67,957,193 18,893 0.028%

> 0.1 μg/L 29,793 18 0.060% 67,957,193 23,963 0.035%

> 1 μg/L 3,033 1 0.033% 116,167,630 2,671 0.002%

	
 3,033 34 1.121% 116,167,630 597,830 0.515%

> 0.1 μg/L 3,033 39 1.286% 116,167,630 912,379 0.785%

> 1 μg/L 32,826 4 0.012% 184,124,823 4,944 0.003%

	
 32,826 46 0.140% 184,124,823 616,723 0.335%

> 0.1 μg/L 32,826 57 0.174% 184,124,823 936,342 0.509%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A41a. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 107 55 52 0.000% 0.000% 0.000%AL 518 387 131 0.000% 0.000% 0.000%AR 1,664 1,423 241 0.000% 0.000% 0.000%AZ 6,943 5,403 1,540 0.000% 0.000% 0.000%CA 14,410 8,397 6,013 0.007% 0.012% 0.000% 10 10 10 10 10 10 10 10CO 2,542 1,831 711 0.787% 0.928% 0.422% 0.01 0.01 0.02 0.02 0.02 0.05 0.055 0.04 0.21 0.21 0.06 0.21CT 1,320 1,011 309 0.303% 0.396% 0.000% 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22DE 1,357 1,312 45 0.000% 0.000% 0.000%FL 2,393 2,327 66 0.418% 0.430% 0.000% 0.002 0.002 0.002 0.002 0.005 0.005 0.008 0.008GA 1,483 1,402 81 0.135% 0.000% 2.469% 2 2 2 2 2 2 2 2HI 2,101 2,004 97 0.000% 0.000% 0.000%IA 151 134 17 1.987% 2.239% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1ID 2,299 2,018 281 0.000% 0.000% 0.000%IL 3,865 3,132 733 0.000% 0.000% 0.000%IN 2,250 2,086 164 0.000% 0.000% 0.000%KY 2,148 568 1,580 2.654% 1.761% 2.975% 0.05 0.5 0.05 0.5 0.5 0.5 0.5 2.85 0.5 5.2 5.2 0.5MA 3,046 2,246 800 0.492% 0.401% 0.750% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1MD 2,775 1,730 1,045 0.072% 0.116% 0.000% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02ME 456 391 65 0.000% 0.000% 0.000%MI 6,886 6,434 452 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.021% 0.022% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1MO 5,563 4,695 868 0.000% 0.000% 0.000%MT 3,009 2,701 308 0.033% 0.000% 0.325% 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11NC 13,604 12,482 1,122 0.000% 0.000% 0.000%ND 65 42 23 0.000% 0.000% 0.000%NE 4,480 4,131 349 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 41 33 8 0.000% 0.000% 0.000%NM 4,357 4,107 250 0.023% 0.024% 0.000% 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06NV 1,620 1,186 434 0.000% 0.000% 0.000%NY 2,926 2,188 738 0.000% 0.000% 0.000%OH 234 97 137 0.000% 0.000% 0.000%OKOR 2,057 1,572 485 0.097% 0.064% 0.206% 0.1 0.1 0.12 0.11 0.1 0.12 0.12 0.1 0.12 0.12 0.1 0.12RI 923 630 293 0.000% 0.000% 0.000%SC 2,907 2,517 390 0.034% 0.040% 0.000% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2SD 956 843 113 0.000% 0.000% 0.000%TN 62 12 50 0.000% 0.000% 0.000%TX 11,038 5,279 5,759 0.000% 0.000% 0.000%UT 7,101 5,915 1,186 0.000% 0.000% 0.000%VA 503 178 325 0.000% 0.000% 0.000%VT 1,317 1,115 202 0.152% 0.090% 0.495% 0.05 0.05 0.1 0.075 0.05 0.1 0.1 0.05 0.1 0.1 0.05 0.1WI 3,185 3,092 93 0.094% 0.065% 1.075% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1WV 627 321 306 2.233% 2.804% 1.634% 0.01 0.01 0.01 0.01 0.01 0.1 0.5 5 0.5 5 5 0.5WY 1,269 958 311 0.000% 0.000% 0.000%Total 135,512 106,879 28,633 0.103% 0.067% 0.234% 0.002 0.002 0.01 0.1 0.045 0.5 0.5 0.5 0.5 10 10 2

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A41b. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 18 11 7 246,541 14,331 232,210 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 175 130 45 2,737,924 625,336 2,112,588 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 450 379 71 2,447,627 905,863 1,541,764 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 939 891 48 6,077,750 2,707,159 3,370,591 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CA 1,674 1,381 293 33,991,142 12,276,578 21,714,564 0.060% 0.072% 0.000% 0.000% 0.000% 0.000%CO 808 589 219 4,990,621 523,712 4,466,909 2.104% 2.377% 1.370% 0.732% 1.441% 0.649%CT 654 617 37 2,589,153 261,886 2,327,267 0.612% 0.648% 0.000% 0.164% 1.623% 0.000%DE 247 244 3 647,226 365,826 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,315 1,294 21 16,791,489 14,552,313 2,239,176 0.380% 0.386% 0.000% 15.509% 17.895% 0.000%GA 297 283 14 997,274 305,252 692,022 0.337% 0.000% 7.143% 0.268% 0.000% 0.386%HI 112 100 12 1,305,882 1,251,254 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 95 93 2 238,892 99,507 139,385 3.158% 3.226% 0.000% 0.513% 1.231% 0.000%ID 856 802 54 1,065,342 818,934 246,408 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,132 1,031 101 9,103,070 2,907,148 6,195,922 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,402 1,358 44 4,866,869 2,547,133 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 18.930% 10.753% 24.000% 19.179% 4.932% 20.441%MA 643 526 117 8,485,275 1,682,893 6,802,382 1.711% 1.331% 3.419% 3.198% 6.699% 2.332%MD 861 793 68 4,906,066 907,959 3,998,107 0.116% 0.126% 0.000% 0.510% 2.753% 0.000%ME 269 241 28 510,420 134,500 375,920 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,930 2,869 61 7,224,826 2,044,970 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.078% 0.079% 0.000% 0.025% 0.037% 0.000%MO 1,471 1,395 76 2,644,644 1,700,183 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.123% 0.000% 1.667% 5.108% 0.000% 9.799%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ND 27 21 6 47,615 40,586 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 36 30 6 1,444,605 143,223 1,301,382 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 695 659 36 1,662,962 1,400,064 262,898 0.144% 0.152% 0.000% 0.144% 0.171% 0.000%NV 292 271 21 961,092 271,201 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,343 1,113 230 4,923,557 981,867 3,941,690 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 46 36 10 3,537,892 147,360 3,390,532 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,083 933 150 2,936,954 572,204 2,364,750 0.185% 0.107% 0.667% 0.565% 0.122% 0.672%RI 105 97 8 902,560 163,122 739,438 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 770 711 59 3,427,270 800,487 2,626,783 0.130% 0.141% 0.000% 0.004% 0.015% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 12 6 6 655,614 145,112 510,502 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,671 1,667,485 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 442 409 33 432,954 181,790 251,164 0.452% 0.244% 3.030% 1.432% 0.169% 2.345%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.213% 0.144% 5.000% 0.687% 0.243% 1.261%WV 335 190 145 1,369,590 205,837 1,163,753 3.582% 4.737% 2.069% 0.828% 0.963% 0.804%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 32,826 29,793 3,033 184,124,823 67,957,193 116,167,630 0.341% 0.205% 1.682% 2.136% 4.099% 0.988%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A41c. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.060% 0.072% 0.000% 50 50 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.337% 0.000% 7.143% 2,671 0 2,671 0.268% 0.000% 0.386%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 1 0 0.412% 1.075% 0.000% 1,898 1,898 0 0.041% 0.506% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 1 0 0.299% 0.526% 0.000% 325 325 0 0.024% 0.158% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 4 3 1 0.012% 0.010% 0.033% 4,944 2,273 2,671 0.003% 0.003% 0.002%

Percent of Population Served 

with At Least One Detection 

> 1 μg/L

State

Number of Systems 

with At Least One Detection 

> 1 μg/L

Percent of Systems 

with At Least One Detection 

> 1 μg/L

Population Served by Systems 

with At Least One Detection 

> 1 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A41d. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.060% 0.072% 0.000% 50 50 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.337% 0.000% 7.143% 2,671 0 2,671 0.268% 0.000% 0.386%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 42 10 32 17.284% 10.753% 21.333% 609,303 18,518 590,785 13.210% 4.932% 13.944%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.597% 0.526% 0.690% 4,699 325 4,374 0.343% 0.158% 0.376%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 46 12 34 0.140% 0.040% 1.121% 616,723 18,893 597,830 0.335% 0.028% 0.515%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A41e. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.060% 0.072% 0.000% 50 50 0 0.000% 0.000% 0.000%CO 1 0 1 0.124% 0.000% 0.457% 3,930 0 3,930 0.079% 0.000% 0.088%CT 4 4 0 0.612% 0.648% 0.000% 4,250 4,250 0 0.164% 1.623% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.337% 0.000% 7.143% 2,671 0 2,671 0.268% 0.000% 0.386%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 43 10 33 17.695% 10.753% 22.000% 863,765 18,518 845,247 18.727% 4.932% 19.950%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 0 1 0.123% 0.000% 1.667% 38,477 0 38,477 5.108% 0.000% 9.799%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 2 1 1 0.185% 0.107% 0.667% 16,580 700 15,880 0.565% 0.122% 0.672%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 1 0 0.130% 0.141% 0.000% 120 120 0 0.004% 0.015% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 3 1 2 0.896% 0.526% 1.379% 6,499 325 6,174 0.475% 0.158% 0.531%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 57 18 39 0.174% 0.060% 1.286% 936,342 23,963 912,379 0.509% 0.035% 0.785%

Percent of Population Served 

with At Least One Detection 

> 0.1 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.1 μg/L

Percent of Systems 

with At Least One Detection 

> 0.1 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.1 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A42. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 50 μg/L 29,767 0 0.000% 67,981,852 0 0.000%'	
 29,767 0 0.000% 67,981,852 0 0.000%	
 29,767 0 0.000% 67,981,852 0 0.000%> 50 μg/L 3,034 0 0.000% 116,756,578 0 0.000%'	
 3,034 0 0.000% 116,756,578 0 0.000%	
 3,034 0 0.000% 116,756,578 0 0.000%> 50 μg/L 32,801 0 0.000% 184,738,430 0 0.000%'	
 32,801 0 0.000% 184,738,430 0 0.000%	
 32,801 0 0.000% 184,738,430 0 0.000%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A42a. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 112 59 53 0.893% 0.000% 1.887% 0.13 0.13 0.13 0.13 0.13 0.13 0.13 0.13AL 549 390 159 0.000% 0.000% 0.000%AR 1,658 1,423 235 2.413% 0.000% 17.021% 0.01 0.01 0.02 0.02 0.1 0.1 0.5 0.5AZ 7,042 5,492 1,550 0.043% 0.018% 0.129% 0.11 0.11 0.11 0.11 0.11 0.405 0.7 0.11 0.7 0.7 0.11 0.7CA 14,048 8,117 5,931 0.014% 0.012% 0.017% 0.04 3.1 0.04 1.57 3.1 0.04 3.1 3.1 0.04 3.1 3.1 0.04CO 2,571 1,837 734 2.334% 0.544% 6.812% 0.03 0.03 0.04 0.16 0.07 0.2 0.775 0.465 0.8 1.7 0.73 1.7CT 1,319 1,010 309 0.227% 0.297% 0.000% 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22DE 1,350 1,305 45 0.074% 0.077% 0.000% 1 1 1 1 1 1 1 1FL 2,428 2,358 70 1.277% 1.315% 0.000% 0.005 0.005 0.25 0.25 0.97 0.97 1.6 1.6GA 1,482 1,402 80 0.067% 0.000% 1.250% 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09HI 2,101 2,004 97 1.523% 0.200% 28.866% 0.05 0.05 0.05 0.08 0.065 0.08 0.14 0.08 0.14 0.16 0.08 0.16IA 149 132 17 0.000% 0.000% 0.000%ID 2,298 2,017 281 0.131% 0.000% 1.068% 0.07 0.07 0.1 0.1 0.5 0.5 0.5 0.5IL 3,898 3,129 769 0.000% 0.000% 0.000%IN 2,242 2,070 172 0.089% 0.000% 1.163% 0.1 0.1 0.15 0.15 0.2 0.2 0.2 0.2KY 2,153 570 1,583 3.019% 1.930% 3.411% 0.001 0.11 0.001 10 10 10 10 10 10 15 15 10MA 3,014 2,227 787 0.398% 0.090% 1.271% 0.04 0.1 0.04 0.1 0.1 0.085 0.14 0.1 0.17 0.2 0.1 0.2MD 2,794 1,735 1,059 0.322% 0.000% 0.850% 0.01 0.01 0.1 0.1 0.5 0.5 0.5 0.5ME 456 391 65 1.096% 0.000% 7.692% 0.16 0.16 0.22 0.22 0.58 0.58 0.58 0.58MI 6,875 6,423 452 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.021% 0.000% 0.709% 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4MO 5,563 4,695 868 0.000% 0.000% 0.000%MT 3,010 2,699 311 0.233% 0.000% 2.251% 0.05 0.05 0.11 0.11 0.2 0.2 0.2 0.2NC 13,576 12,453 1,123 0.243% 0.104% 1.781% 0.1 0.1 0.11 0.19 0.29 0.155 0.31 0.4 0.235 1.86 1.86 0.28ND 67 42 25 0.000% 0.000% 0.000%NE 4,480 4,131 349 0.000% 0.000% 0.000%NH 4,197 3,875 322 0.262% 0.026% 3.106% 0.1 0.6 0.1 0.1 0.6 0.1 0.38 0.6 0.34 0.6 0.6 0.38NJ 40 33 7 2.500% 3.030% 0.000% 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19NM 4,360 4,108 252 0.023% 0.024% 0.000% 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7NV 1,621 1,189 432 0.062% 0.000% 0.231% 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07NY 2,921 2,184 737 0.000% 0.000% 0.000%OH 229 95 134 0.000% 0.000% 0.000%OKOR 2,051 1,567 484 0.098% 0.000% 0.413% 0.1 0.1 0.115 0.115 0.13 0.13 0.13 0.13RI 923 630 293 0.000% 0.000% 0.000%SC 2,880 2,490 390 0.313% 0.361% 0.000% 10 10 10 10 10 10 10 10SD 952 843 109 0.000% 0.000% 0.000%TN 63 10 53 0.000% 0.000% 0.000%TX 11,038 5,279 5,759 0.109% 0.019% 0.191% 0.3 0.31 0.3 0.38 0.31 0.39 0.69 0.31 0.69 0.71 0.31 0.71UT 7,108 5,920 1,188 0.070% 0.068% 0.084% 0.3 0.3 0.4 0.3 0.3 0.4 0.4 0.3 0.4 0.4 0.3 0.4VA 505 178 327 0.000% 0.000% 0.000%VT 1,314 1,112 202 0.228% 0.090% 0.990% 0.1 0.2 0.1 0.1 0.2 0.1 0.2 0.2 0.1 0.2 0.2 0.1WI 3,184 3,091 93 0.000% 0.000% 0.000%WV 650 338 312 2.154% 2.663% 1.603% 0.05 0.05 0.05 0.05 0.05 0.1 0.5 0.53 0.5 0.53 0.53 0.5WY 1,258 948 310 0.477% 0.000% 1.935% 0.03 0.03 0.14 0.14 0.25 0.25 0.25 0.25Total 135,290 106,621 28,669 0.278% 0.098% 0.949% 0.001 0.005 0.001 0.15 0.275 0.13 10 10 10 15 15 10

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A42b. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 18 11 7 246,541 14,331 232,210 5.556% 0.000% 14.286% 1.254% 0.000% 1.332%AL 177 131 46 3,492,436 718,414 2,774,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 450 379 71 2,447,627 905,863 1,541,764 5.333% 0.000% 33.803% 21.686% 0.000% 34.428%AZ 937 889 48 6,069,368 2,698,777 3,370,591 0.320% 0.112% 4.167% 39.044% 25.054% 50.246%CA 1,640 1,353 287 33,859,665 12,218,039 21,641,626 0.122% 0.074% 0.348% 0.016% 0.046% 0.000%CO 808 589 219 4,990,621 523,712 4,466,909 3.960% 1.698% 10.046% 5.929% 0.481% 6.568%CT 654 617 37 2,589,153 261,886 2,327,267 0.459% 0.486% 0.000% 0.144% 1.423% 0.000%DE 247 244 3 647,226 365,826 281,400 0.405% 0.410% 0.000% 0.010% 0.018% 0.000%FL 1,317 1,294 23 16,795,482 14,552,477 2,243,005 1.139% 1.159% 0.000% 16.924% 19.533% 0.000%GA 297 283 14 997,274 305,252 692,022 0.337% 0.000% 7.143% 18.049% 0.000% 26.011%HI 112 100 12 1,305,882 1,251,254 54,628 4.464% 2.000% 25.000% 2.051% 1.498% 14.707%IA 96 94 2 238,964 99,579 139,385 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 855 801 54 1,065,312 818,904 246,408 0.234% 0.000% 3.704% 17.469% 0.000% 75.524%IL 1,132 1,031 101 9,103,070 2,907,148 6,195,922 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,401 1,357 44 4,866,289 2,546,553 2,319,736 0.071% 0.000% 2.273% 0.033% 0.000% 0.069%KY 243 93 150 4,612,320 375,460 4,236,860 20.988% 11.828% 26.667% 22.093% 7.186% 23.414%MA 642 525 117 8,484,975 1,682,593 6,802,382 1.246% 0.381% 5.128% 45.408% 0.769% 56.449%MD 861 793 68 4,906,066 907,959 3,998,107 0.465% 0.000% 5.882% 70.920% 0.000% 87.026%ME 269 241 28 510,420 134,500 375,920 1.115% 0.000% 10.714% 1.622% 0.000% 2.203%MI 2,934 2,873 61 7,227,105 2,047,249 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.078% 0.000% 3.448% 0.001% 0.000% 0.004%MO 1,471 1,395 76 2,644,644 1,700,183 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.369% 0.000% 5.000% 5.261% 0.000% 10.092%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.846% 0.449% 7.299% 4.541% 11.510% 2.196%ND 26 20 6 45,611 38,582 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.404% 0.084% 9.756% 6.598% 4.799% 7.894%NJ 36 30 6 1,444,605 143,223 1,301,382 2.778% 3.333% 0.000% 0.026% 0.262% 0.000%NM 695 659 36 1,662,962 1,400,064 262,898 0.144% 0.152% 0.000% 0.024% 0.029% 0.000%NV 292 271 21 961,092 271,201 689,891 0.342% 0.000% 4.762% 5.879% 0.000% 8.190%NY 1,343 1,113 230 4,923,707 982,017 3,941,690 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 46 36 10 3,537,892 147,360 3,390,532 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,083 933 150 2,936,954 572,204 2,364,750 0.185% 0.000% 1.333% 0.011% 0.000% 0.014%RI 105 97 8 902,560 163,122 739,438 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 767 708 59 3,426,157 799,374 2,626,783 0.913% 0.989% 0.000% 0.018% 0.077% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 11 5 6 650,577 144,562 506,015 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.450% 0.060% 2.374% 0.240% 0.003% 0.327%UT 426 389 37 2,500,671 1,667,485 833,186 0.469% 0.257% 2.703% 0.937% 1.379% 0.052%VA 184 71 113 2,391,419 30,317 2,361,102 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 441 408 33 432,879 181,715 251,164 0.454% 0.245% 3.030% 1.432% 0.169% 2.345%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 344 197 147 1,370,985 206,326 1,164,659 3.488% 4.569% 2.041% 0.827% 0.961% 0.804%WY 304 256 48 446,177 129,229 316,948 0.987% 0.000% 6.250% 0.246% 0.000% 0.346%Total 32,801 29,767 3,034 184,738,430 67,981,852 116,756,578 0.686% 0.262% 4.845% 8.321% 5.641% 9.882%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A42c. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 50 μg/L

State

Number of Systems 

with At Least One Detection 

> 50 μg/L

Percent of Systems 

with At Least One Detection 

> 50 μg/L

Population Served by Systems 

with At Least One Detection 

> 50 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A42d. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

'	


State

Number of Systems 

with At Least One Detection 

'	


Percent of Systems 

with At Least One Detection 

'	


Population Served by Systems 

with At Least One Detection 

'	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A42e. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A43. LIndane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.2 μg/L 30,143 2 0.007% 68,277,043 462 0.001%	
 30,143 11 0.036% 68,277,043 36,143 0.053%

> 0.2 μg/L 3,122 1 0.032% 118,981,892 4,374 0.004%

	
 3,122 4 0.128% 118,981,892 512,063 0.430%

> 0.2 μg/L 33,265 3 0.009% 187,258,935 4,836 0.003%	
 33,265 15 0.045% 187,258,935 548,206 0.293%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

Table A43a. LIndane (gamma-Hexachl

AK 99 50 49 0.000% 0.000% 0.000%AL 562 424 138 0.356% 0.236% 0.725% 0.15 0.16 0.15 0.155 0.16 0.15 0.16 0.16 0.15 0.16 0.16 0.15AR 1,664 1,423 241 0.000% 0.000% 0.000%AZ 7,221 5,643 1,578 0.028% 0.035% 0.000% 0.02 0.02 0.06 0.06 0.1 0.1 0.1 0.1CA 14,361 8,298 6,063 0.007% 0.012% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1CO 2,538 1,837 701 0.039% 0.054% 0.000% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02CT 1,602 1,015 587 0.499% 0.099% 1.193% 0.01 0.05 0.01 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05DE 758 729 29 1.319% 1.372% 0.000% 0.01 0.01 0.025 0.025 0.075 0.075 0.1 0.1FL 2,392 2,325 67 0.502% 0.516% 0.000% 0.003 0.003 0.003 0.003 0.006 0.006 0.06 0.06GA 1,482 1,402 80 0.000% 0.000% 0.000%HI 1,948 1,851 97 0.000% 0.000% 0.000%IA 149 132 17 0.000% 0.000% 0.000%ID 1,739 1,482 257 0.000% 0.000% 0.000%IL 4,684 3,949 735 0.064% 0.076% 0.000% 0.002 0.002 0.02 0.02 0.05 0.05 0.05 0.05IN 2,247 2,084 163 0.178% 0.192% 0.000% 0.02 0.02 0.05 0.05 0.07 0.07 0.07 0.07KY 1,753 445 1,308 0.342% 0.225% 0.382% 0.001 0.01 0.001 0.11 0.01 0.2 0.2 0.01 0.2 0.2 0.01 0.2MA 3,033 2,244 789 0.165% 0.045% 0.507% 0.02 0.02 0.02 0.02 0.02 0.02 0.07 0.02 0.07 0.07 0.02 0.07MD 2,720 1,726 994 0.294% 0.000% 0.805% 0.01 0.01 0.01 0.03 0.03 0.03 0.1 0.1 0.1 0.1 0.1 0.1ME 456 391 65 0.000% 0.000% 0.000%MI 6,875 6,423 452 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 5,559 4,691 868 0.000% 0.000% 0.000%MT 3,002 2,694 308 0.000% 0.000% 0.000%NC 13,616 12,479 1,137 0.492% 0.537% 0.000% 0.02 0.02 0.06 0.06 0.12 0.12 0.69 0.69ND 407 341 66 0.000% 0.000% 0.000%NE 4,480 4,131 349 0.022% 0.024% 0.000% 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 41 33 8 2.439% 3.030% 0.000% 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05NM 4,355 4,105 250 0.000% 0.000% 0.000%NV 1,633 1,194 439 0.000% 0.000% 0.000%NY 2,926 2,192 734 0.000% 0.000% 0.000%OH 669 433 236 0.000% 0.000% 0.000%OKOR 2,055 1,570 485 0.049% 0.000% 0.206% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02RI 601 414 187 0.166% 0.242% 0.000% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02SC 2,929 2,538 391 0.000% 0.000% 0.000%SD 953 844 109 0.000% 0.000% 0.000%TN 79 13 66 0.000% 0.000% 0.000%TX 11,038 5,279 5,759 0.000% 0.000% 0.000%UT 7,115 5,927 1,188 0.000% 0.000% 0.000%VA 459 165 294 0.000% 0.000% 0.000%VT 1,322 1,119 203 0.076% 0.089% 0.000% 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06WI 3,183 3,090 93 0.000% 0.000% 0.000%WV 643 335 308 2.022% 2.687% 1.299% 0.004 0.004 0.0044 0.0044 0.0044 0.0122 0.5 0.5 0.5 0.5 0.5 0.5WY 1,283 963 320 0.000% 0.000% 0.000%Total 135,585 106,917 28,668 0.108% 0.109% 0.105% 0.001 0.002 0.001 0.04 0.04 0.03 0.11 0.11 0.2 0.69 0.69 0.5

orocyclohexane) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 14 9 5 246,238 14,248 231,990 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 178 132 46 2,786,308 640,232 2,146,076 1.124% 0.758% 2.174% 8.924% 0.459% 11.450%AR 450 379 71 2,447,627 905,863 1,541,764 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 948 900 48 6,081,133 2,710,542 3,370,591 0.211% 0.222% 0.000% 0.012% 0.028% 0.000%CA 1,645 1,351 294 33,787,721 12,066,131 21,721,590 0.061% 0.074% 0.000% 0.020% 0.055% 0.000%CO 811 592 219 4,991,819 524,910 4,466,909 0.123% 0.169% 0.000% 0.006% 0.054% 0.000%CT 657 619 38 2,595,377 261,490 2,333,887 0.761% 0.162% 10.526% 17.147% 0.140% 19.052%DE 201 198 3 628,982 347,582 281,400 0.995% 1.010% 0.000% 11.717% 21.202% 0.000%FL 1,315 1,294 21 16,791,489 14,552,313 2,239,176 0.456% 0.464% 0.000% 15.540% 17.931% 0.000%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 100 88 12 1,256,886 1,202,258 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 96 94 2 238,964 99,579 139,385 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 723 676 47 979,385 742,709 236,676 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,371 1,267 104 9,186,700 2,986,303 6,200,397 0.219% 0.237% 0.000% 0.170% 0.524% 0.000%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.214% 0.221% 0.000% 0.141% 0.268% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 1.646% 1.075% 2.000% 7.746% 0.058% 8.427%MA 644 527 117 8,485,298 1,682,916 6,802,382 0.621% 0.190% 2.564% 1.923% 0.903% 2.175%MD 861 793 68 4,906,066 907,959 3,998,107 0.465% 0.000% 5.882% 71.708% 0.000% 87.992%ME 269 241 28 510,420 134,500 375,920 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,935 2,874 61 7,227,231 2,047,375 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,471 1,395 76 2,644,644 1,700,183 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 1.311% 1.391% 0.000% 1.084% 4.303% 0.000%ND 208 181 27 559,142 253,917 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.131% 0.133% 0.000% 0.005% 0.012% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 36 30 6 1,444,605 143,223 1,301,382 2.778% 3.333% 0.000% 2.284% 23.041% 0.000%NM 695 659 36 1,662,962 1,400,064 262,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 288 267 21 959,822 269,931 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,344 1,113 231 4,921,386 978,109 3,943,277 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 280 202 78 6,539,484 514,829 6,024,655 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,084 934 150 2,937,354 572,604 2,364,750 0.092% 0.000% 0.667% 0.417% 0.000% 0.518%RI 86 77 9 902,061 162,083 739,978 1.163% 1.299% 0.000% 0.510% 2.838% 0.000%SC 770 711 59 3,427,270 800,487 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 19 7 12 752,805 145,338 607,467 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 428 391 37 2,502,301 1,669,115 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 171 67 104 2,129,631 28,445 2,101,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 442 409 33 432,910 181,746 251,164 0.226% 0.244% 0.000% 0.071% 0.169% 0.000%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 342 195 147 1,368,695 204,036 1,164,659 3.216% 4.615% 1.361% 0.697% 0.971% 0.649%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 33,265 30,143 3,122 187,258,935 68,277,043 118,981,892 0.253% 0.219% 0.577% 4.048% 4.169% 3.978%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting

Table A43b. LIndane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 137 137 0 0.002% 0.008% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.585% 0.513% 0.680% 4,699 325 4,374 0.343% 0.159% 0.376%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Total 3 2 1 0.009% 0.007% 0.032% 4,836 462 4,374 0.003% 0.001% 0.004%

Percent of Population Served 

with At Least One Detection 

> 0.2 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.2 μg/L

Percent of Systems 

with At Least One Detection 

> 0.2 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.2 μg/L

Table A43c. LIndane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A43d. LIndane (gamma-Hexachlorocyclohexane) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 2 1 1 1.124% 0.758% 2.174% 248,664 2,937 245,727 8.924% 0.459% 11.450%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 1 0 0.105% 0.111% 0.000% 245 245 0 0.004% 0.009% 0.000%CA 1 1 0 0.061% 0.074% 0.000% 6,650 6,650 0 0.020% 0.055% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 1 1 0 0.498% 0.505% 0.000% 4,800 4,800 0 0.763% 1.381% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.412% 0.000% 0.667% 254,462 0 254,462 5.517% 0.000% 6.006%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 0 1 0.116% 0.000% 1.471% 7,500 0 7,500 0.153% 0.000% 0.188%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 6 6 0 0.254% 0.269% 0.000% 21,186 21,186 0 0.308% 1.222% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.585% 0.513% 0.680% 4,699 325 4,374 0.343% 0.159% 0.376%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 15 11 4 0.045% 0.036% 0.128% 548,206 36,143 512,063 0.293% 0.053% 0.430%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A44. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.002 mg/L 44,863 64 0.143% 85,514,854 617,666 0.722%	
 44,863 223 0.497% 85,514,854 2,282,255 2.669%

> 0.002 mg/L 3,996 18 0.450% 144,338,525 1,973,654 1.367%

	
 3,996 51 1.276% 144,338,525 10,552,870 7.311%

> 0.002 mg/L 48,859 82 0.168% 229,853,379 2,591,320 1.127%

	
 48,859 274 0.561% 229,853,379 12,835,125 5.584%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A44a. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 866 613 253 1.963% 2.121% 1.581% 0.0002 0.0002 0.0002 0.0003 0.0003 0.0002 0.00051 0.00051 0.00027 0.0071 0.0071 0.00027AL 2,683 1,829 854 1.416% 1.093% 2.108% 0.00003 0.00006 0.00003 0.0005 0.00047 0.00059 0.00147 0.0011 0.0015 0.002 0.002 0.0019AR 2,186 1,529 657 0.091% 0.131% 0.000% 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005AZ 6,219 4,855 1,364 1.769% 1.833% 1.540% 0.0001 0.0001 0.00012 0.0003 0.00039 0.0002 0.0011 0.0011 0.001 0.0031 0.0031 0.0011CA 34,622 20,422 14,200 1.765% 2.155% 1.204% 2.1E-05 2.1E-05 2.2E-05 0.00011 0.00012 0.0001 0.0012 0.0012 0.0012 0.01 0.01 0.009CO 4,378 2,321 2,057 1.256% 0.991% 1.556% 0.00005 0.0001 0.00005 0.0002 0.0002 0.00021 0.00097 0.00097 0.00051 0.002 0.0018 0.002CT 2,589 1,866 723 1.159% 1.447% 0.415% 0.00009 0.00009 0.0002 0.0003 0.00029 0.0003 0.002 0.002 0.002 0.002 0.002 0.002DE 762 709 53 2.493% 2.539% 1.887% 0.0001 0.0001 0.0001 0.0005 0.0005 0.0001 0.002 0.002 0.0001 0.01 0.01 0.0001FL 2,149 2,080 69 5.398% 5.481% 2.899% 0.0001 0.0001 0.0001 0.0002 0.0002 0.0004 0.0007 0.0007 0.0007 0.002 0.002 0.0007GA 3,646 3,005 641 0.082% 0.033% 0.312% 0.00026 0.0016 0.00026 0.0016 0.0016 0.00263 0.005 0.0016 0.005 0.005 0.0016 0.005HI 1,178 1,116 62 0.170% 0.179% 0.000% 0.0006 0.0006 0.00065 0.00065 0.0007 0.0007 0.0007 0.0007IA 1,491 1,228 263 0.671% 0.814% 0.000% 0.0002 0.0002 0.00037 0.00037 0.00081 0.00081 0.001 0.001ID 2,664 2,386 278 1.051% 1.006% 1.439% 0.0001 0.0001 0.0002 0.00042 0.00047 0.0003 0.0022 0.0022 0.0009 0.06 0.06 0.0009IL 3,420 3,017 403 0.526% 0.464% 0.993% 6.5E-05 6.5E-05 0.00011 0.0002 0.00022 0.00017 0.00096 0.00096 0.0003 0.002 0.002 0.0003IN 4,699 4,216 483 1.000% 0.783% 2.899% 0.0001 0.0001 0.0001 0.00023 0.0002 0.00055 0.0013 0.0015 0.0009 0.002 0.002 0.001KY 1,758 532 1,226 4.039% 2.820% 4.568% 0.0001 0.0002 0.0001 0.0003 0.0003 0.0003 0.0007 0.0085 0.0007 0.0086 0.0086 0.003MA 2,982 2,022 960 1.979% 2.324% 1.250% 0.00004 0.00004 0.0002 0.00027 0.00026 0.0005 0.001 0.001 0.0005 0.01 0.01 0.002MD 5,096 3,986 1,110 0.608% 0.477% 1.081% 0.0001 0.0002 0.0001 0.0005 0.0005 0.00055 0.0019 0.002 0.0016 0.006 0.006 0.0032ME 2,702 2,302 400 1.925% 2.215% 0.250% 0.00005 0.00005 0.0001 0.0001 0.0001 0.0001 0.00013 0.00013 0.0001 0.0003 0.0003 0.0001MI 5,591 5,436 155 4.525% 4.507% 5.161% 0.00003 0.00003 0.00003 0.00004 0.00004 0.00004 0.00013 0.00014 0.0001 0.00506 0.00506 0.0001MN 3,207 3,159 48 0.904% 0.823% 6.250% 0.00003 0.00003 0.00003 0.00006 0.00006 0.00005 0.00027 0.00027 0.00012 0.00037 0.00037 0.00012MO 5,704 4,923 781 0.666% 0.711% 0.384% 0.00004 0.00004 0.00016 0.00028 0.00028 0.00019 0.00087 0.00087 0.00032 0.00114 0.00114 0.00032MT 2,751 2,472 279 0.327% 0.324% 0.358% 0.0002 0.0002 0.0002 0.0003 0.0003 0.0002 0.0028 0.0028 0.0002 0.0028 0.0028 0.0002NC 9,222 7,786 1,436 1.247% 1.259% 1.184% 0.00006 0.0001 0.00006 0.0003 0.0003 0.0003 0.0007 0.0007 0.0006 0.03 0.03 0.0007ND 348 304 44 0.000% 0.000% 0.000%NE 1,937 1,849 88 0.000% 0.000% 0.000%NH 2,928 2,764 164 0.376% 0.398% 0.000% 0.0001 0.0001 0.0003 0.0003 0.0026 0.0026 0.0078 0.0078NJ 6,722 6,004 718 5.356% 5.763% 1.950% 0.00004 0.00004 0.00004 0.0004 0.00042 0.00025 0.00157 0.0016 0.0005 0.03 0.03 0.001NM 3,508 3,182 326 1.226% 1.288% 0.613% 0.0002 0.0002 0.0005 0.0003 0.0003 0.00125 0.0014 0.0014 0.002 0.0026 0.0026 0.002NV 1,836 1,305 531 1.634% 1.686% 1.507% 0.0001 0.0001 0.0002 0.0004 0.00039 0.00042 0.00091 0.001 0.00081 0.0028 0.0028 0.00081NY 3,398 2,546 852 0.971% 0.943% 1.056% 0.0002 0.0002 0.0002 0.0002 0.0002 0.00028 0.002 0.002 0.0021 0.004 0.004 0.0021OH 4,553 3,927 626 1.340% 1.477% 0.479% 0.00012 0.00012 0.00021 0.00035 0.00036 0.0003 0.001 0.00105 0.00065 0.02 0.02 0.00065OK 420 346 74 0.476% 0.578% 0.000% 0.00005 0.00005 0.00014 0.00014 0.00022 0.00022 0.00022 0.00022OR 1,320 957 363 0.455% 0.627% 0.000% 0.0002 0.0002 0.00095 0.00095 0.0013 0.0013 0.0013 0.0013RI 904 674 230 0.221% 0.297% 0.000% 0.0025 0.0025 0.00625 0.00625 0.01 0.01 0.01 0.01SC 3,403 2,940 463 2.116% 1.259% 7.559% 0.0002 0.0002 0.00032 0.00045 0.0003 0.00049 0.002 0.0018 0.0039 0.02 0.0045 0.02SD 388 359 29 1.289% 1.114% 3.448% 0.0002 0.0002 0.0011 0.0008 0.0005 0.0011 0.0013 0.0013 0.0011 0.0013 0.0013 0.0011TN 1,631 482 1,149 1.165% 0.415% 1.480% 0.00009 0.0002 0.00009 0.0003 0.0007 0.0003 0.0012 0.0012 0.0011 0.0016 0.0012 0.0016TX 14,712 12,141 2,571 0.387% 0.387% 0.389% 0.0002 0.0002 0.00021 0.0004 0.0005 0.0003 0.00125 0.0013 0.00053 0.0019 0.0019 0.00053UT 6,931 5,432 1,499 5.194% 5.468% 4.203% 0.0001 0.0001 0.0001 0.0002 0.0002 0.0002 0.0004 0.0004 0.0004 0.001 0.001 0.0006VA 2,804 2,195 609 0.713% 0.774% 0.493% 0.0002 0.0002 0.0002 0.0002 0.0002 0.0002 0.00075 0.001 0.0005 0.0026 0.0026 0.0005VT 2,059 1,738 321 0.826% 0.921% 0.312% 0.00003 0.00003 0.0003 0.0002 0.0002 0.0003 0.002 0.002 0.0003 0.02 0.02 0.0003WI 7,023 6,851 172 4.841% 4.904% 2.326% 2.5E-05 2.5E-05 0.0001 0.00015 0.00015 0.00045 0.00042 0.00041 0.0028 0.0077 0.0077 0.0028WV 1,116 423 693 3.495% 4.965% 2.597% 9.3E-05 9.3E-05 9.3E-05 0.001 0.001 0.00057 0.002 0.001 0.0027 0.1 0.002 0.1WY 1,123 875 248 0.890% 1.029% 0.403% 0.0001 0.0001 0.003 0.00055 0.0005 0.003 0.00225 0.0015 0.003 0.003 0.0015 0.003Total 181,629 141,104 40,525 1.789% 1.894% 1.426% 2.1E-05 2.1E-05 2.2E-05 0.0002 0.0002 0.0002 0.001 0.001 0.001 0.1 0.06 0.1

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A44b. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 490 389 101 546,448 210,227 336,221 3.061% 3.085% 2.970% 43.258% 1.748% 69.213%AL 352 279 73 4,701,100 1,463,066 3,238,034 7.955% 5.735% 16.438% 28.081% 10.073% 36.218%AR 453 381 72 2,452,800 909,774 1,543,026 0.221% 0.262% 0.000% 0.020% 0.054% 0.000%AZ 1,049 1,001 48 6,161,306 2,790,715 3,370,591 5.338% 4.795% 16.667% 51.813% 10.985% 85.617%CA 3,772 3,252 520 36,340,528 13,511,104 22,829,424 6.098% 5.566% 9.423% 33.929% 32.197% 34.954%CO 838 617 221 4,998,506 533,275 4,465,231 4.415% 2.593% 9.502% 17.246% 1.553% 19.121%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 2.393% 2.210% 7.692% 3.019% 1.056% 3.341%DE 281 278 3 679,823 398,423 281,400 2.135% 1.799% 33.333% 20.553% 8.648% 37.409%FL 1,335 1,309 26 17,251,183 15,005,141 2,246,042 4.270% 4.202% 7.692% 26.294% 28.131% 14.021%GA 1,734 1,618 116 7,466,977 1,574,196 5,892,781 0.173% 0.062% 1.724% 1.371% 0.011% 1.735%HI 107 95 12 1,303,767 1,249,139 54,628 0.935% 1.053% 0.000% 0.031% 0.032% 0.000%IA 967 934 33 2,500,395 1,391,769 1,108,626 1.034% 1.071% 0.000% 1.443% 2.593% 0.000%ID 896 848 48 1,050,473 806,038 244,435 2.567% 2.594% 2.083% 26.491% 11.449% 76.094%IL 1,489 1,386 103 9,168,041 2,967,969 6,200,072 1.075% 0.938% 2.913% 4.084% 6.653% 2.854%IN 1,622 1,573 49 4,980,031 2,619,576 2,360,455 2.528% 1.971% 20.408% 29.845% 4.558% 57.907%KY 242 93 149 4,602,489 375,460 4,227,029 18.182% 10.753% 22.819% 43.234% 7.753% 46.386%MA 676 558 118 8,525,575 1,718,151 6,807,424 5.030% 5.197% 4.237% 43.332% 3.528% 53.379%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 2.505% 1.649% 14.706% 40.382% 25.692% 44.146%ME 806 752 54 727,707 292,103 435,604 4.839% 5.053% 1.852% 5.906% 13.898% 0.546%MI 2,850 2,801 49 6,539,864 1,815,364 4,724,500 8.316% 8.283% 10.204% 59.692% 22.622% 73.936%MN 1,438 1,411 27 3,894,967 2,661,430 1,233,537 1.878% 1.772% 7.407% 3.698% 4.478% 2.015%MO 1,421 1,344 77 3,006,743 1,692,282 1,314,461 2.111% 2.083% 2.597% 1.817% 1.400% 2.354%MT 845 786 59 757,505 365,106 392,399 0.828% 0.763% 1.695% 0.445% 0.900% 0.022%NC 2,285 2,146 139 6,973,678 1,708,512 5,265,166 4.245% 3.868% 10.072% 13.455% 6.417% 15.739%ND 217 190 27 563,069 257,844 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 731 720 11 1,449,290 672,810 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,216 1,175 41 942,517 392,718 549,799 0.658% 0.681% 0.000% 2.179% 5.230% 0.000%NJ 1,372 1,335 37 7,762,526 2,726,580 5,035,946 12.026% 11.685% 24.324% 21.470% 34.076% 14.645%NM 720 681 39 1,667,049 1,400,501 266,548 5.000% 4.993% 5.128% 8.281% 9.233% 3.282%NV 324 304 20 970,526 280,727 689,799 7.407% 5.921% 30.000% 46.780% 17.939% 58.517%NY 1,571 1,332 239 11,195,033 1,218,149 9,976,884 2.101% 1.802% 3.766% 0.855% 0.974% 0.841%OH 1,915 1,790 125 10,216,143 3,121,206 7,094,937 2.663% 2.682% 2.400% 0.952% 1.473% 0.723%OK 202 175 27 749,266 276,712 472,554 0.990% 1.143% 0.000% 0.219% 0.594% 0.000%OR 733 611 122 2,777,164 487,418 2,289,746 0.819% 0.982% 0.000% 0.124% 0.706% 0.000%RI 143 134 9 913,584 173,606 739,978 1.399% 1.493% 0.000% 3.139% 16.521% 0.000%SC 822 757 65 3,462,560 804,033 2,658,527 5.231% 3.435% 26.154% 36.478% 3.526% 46.444%SD 235 224 11 328,972 237,011 91,961 2.128% 1.786% 9.091% 22.993% 4.919% 69.576%TN 350 161 189 5,683,572 1,460,816 4,222,756 4.286% 1.242% 6.878% 12.423% 0.040% 16.707%TX 4,888 4,547 341 25,060,220 9,275,719 15,784,501 1.002% 0.968% 1.466% 5.944% 14.742% 0.773%UT 507 457 50 2,543,652 1,686,017 857,635 18.343% 16.849% 32.000% 59.137% 49.220% 78.633%VA 1,582 1,414 168 4,803,450 634,384 4,169,066 0.822% 0.778% 1.190% 0.202% 0.889% 0.097%VT 598 556 42 490,389 226,621 263,768 2.508% 2.518% 2.381% 1.151% 1.210% 1.099%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 13.165% 13.145% 15.000% 16.875% 24.966% 5.623%WV 450 290 160 1,415,227 234,687 1,180,540 7.778% 7.241% 8.750% 4.848% 4.737% 4.870%WY 304 255 49 446,184 129,168 317,016 2.961% 3.137% 2.041% 0.858% 1.366% 0.651%Total 48,859 44,863 3,996 229,853,379 85,514,854 144,338,525 3.964% 3.669% 7.282% 20.052% 17.131% 21.783%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A44c. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.204% 0.257% 0.000% 200 200 0 0.037% 0.095% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 2 2 0 0.191% 0.200% 0.000% 277 277 0 0.004% 0.010% 0.000%CA 16 10 6 0.424% 0.308% 1.154% 1,873,292 502,592 1,370,700 5.155% 3.720% 6.004%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 1 1 0 0.356% 0.360% 0.000% 6,150 6,150 0 0.905% 1.544% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.058% 0.000% 0.862% 2,671 0 2,671 0.036% 0.000% 0.045%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 3 3 0 0.335% 0.354% 0.000% 2,163 2,163 0 0.206% 0.268% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 3 2 1 1.240% 2.151% 0.671% 99,748 4,877 94,871 2.167% 1.299% 2.244%MA 2 2 0 0.296% 0.358% 0.000% 745 745 0 0.009% 0.043% 0.000%MD 2 1 1 0.193% 0.103% 1.471% 4,058 58 4,000 0.081% 0.006% 0.100%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 2 2 0 0.070% 0.071% 0.000% 109 109 0 0.002% 0.006% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 150 150 0 0.020% 0.041% 0.000%NC 2 2 0 0.088% 0.093% 0.000% 65 65 0 0.001% 0.004% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 2 2 0 0.164% 0.170% 0.000% 113 113 0 0.012% 0.029% 0.000%NJ 16 16 0 1.166% 1.199% 0.000% 27,879 27,879 0 0.359% 1.022% 0.000%NM 1 1 0 0.139% 0.147% 0.000% 23,540 23,540 0 1.412% 1.681% 0.000%NV 1 1 0 0.309% 0.329% 0.000% 30 30 0 0.003% 0.011% 0.000%NY 2 1 1 0.127% 0.075% 0.418% 18,643 3,000 15,643 0.167% 0.246% 0.157%OH 2 2 0 0.104% 0.112% 0.000% 960 960 0 0.009% 0.031% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 2 2 0 1.399% 1.493% 0.000% 28,681 28,681 0 3.139% 16.521% 0.000%SC 6 3 3 0.730% 0.396% 4.615% 426,360 1,699 424,661 12.313% 0.211% 15.974%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.071% 0.000% 98 98 0 0.002% 0.015% 0.000%VT 1 1 0 0.167% 0.180% 0.000% 40 40 0 0.008% 0.018% 0.000%WI 8 7 1 0.439% 0.388% 5.000% 35,580 14,240 21,340 0.880% 0.605% 1.261%WV 3 0 3 0.667% 0.000% 1.875% 37,703 0 37,703 2.664% 0.000% 3.194%WY 1 0 1 0.329% 0.000% 2.041% 2,065 0 2,065 0.463% 0.000% 0.651%Total 82 64 18 0.168% 0.143% 0.450% 2,591,320 617,666 1,973,654 1.127% 0.722% 1.367%

Percent of Population Served 

with At Least One Detection 

> 0.002 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.002 mg/L

Percent of Systems 

with At Least One Detection 

> 0.002 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.002 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A44d. Mercury (Inorganic) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.204% 0.257% 0.000% 200 200 0 0.037% 0.095% 0.000%AL 6 2 4 1.705% 0.717% 5.479% 958,009 3,342 954,667 20.378% 0.228% 29.483%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 13 11 2 1.239% 1.099% 4.167% 715,990 90,765 625,225 11.621% 3.252% 18.549%CA 55 39 16 1.458% 1.199% 3.077% 7,342,316 1,126,527 6,215,789 20.204% 8.338% 27.227%CO 4 2 2 0.477% 0.324% 0.905% 147,212 445 146,767 2.945% 0.083% 3.287%CT 7 6 1 0.598% 0.531% 2.564% 37,823 1,756 36,067 1.393% 0.459% 1.545%DE 1 1 0 0.356% 0.360% 0.000% 6,150 6,150 0 0.905% 1.544% 0.000%FL 8 8 0 0.599% 0.611% 0.000% 515,436 515,436 0 2.988% 3.435% 0.000%GA 2 1 1 0.115% 0.062% 0.862% 2,846 175 2,671 0.038% 0.011% 0.045%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 1 1 0 0.103% 0.107% 0.000% 510 510 0 0.020% 0.037% 0.000%ID 3 3 0 0.335% 0.354% 0.000% 2,163 2,163 0 0.206% 0.268% 0.000%IL 1 1 0 0.067% 0.072% 0.000% 684 684 0 0.007% 0.023% 0.000%IN 8 7 1 0.493% 0.445% 2.041% 49,172 43,184 5,988 0.987% 1.649% 0.254%KY 3 2 1 1.240% 2.151% 0.671% 99,748 4,877 94,871 2.167% 1.299% 2.244%MA 6 5 1 0.888% 0.896% 0.847% 11,042 8,156 2,886 0.130% 0.475% 0.042%MD 5 2 3 0.482% 0.206% 4.412% 1,725,538 238 1,725,300 34.356% 0.023% 43.153%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 2 2 0 0.070% 0.071% 0.000% 109 109 0 0.002% 0.006% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.070% 0.074% 0.000% 235 235 0 0.008% 0.014% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 150 150 0 0.020% 0.041% 0.000%NC 5 5 0 0.219% 0.233% 0.000% 2,206 2,206 0 0.032% 0.129% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 4 4 0 0.329% 0.340% 0.000% 19,166 19,166 0 2.033% 4.880% 0.000%NJ 41 40 1 2.988% 2.996% 2.703% 274,161 124,161 150,000 3.532% 4.554% 2.979%NM 7 6 1 0.972% 0.881% 2.564% 36,726 28,102 8,624 2.203% 2.007% 3.235%NV 3 3 0 0.926% 0.987% 0.000% 3,163 3,163 0 0.326% 1.127% 0.000%NY 5 4 1 0.318% 0.300% 0.418% 19,087 3,444 15,643 0.170% 0.283% 0.157%OH 6 6 0 0.313% 0.335% 0.000% 7,974 7,974 0 0.078% 0.255% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 3 3 0 0.409% 0.491% 0.000% 3,306 3,306 0 0.119% 0.678% 0.000%RI 2 2 0 1.399% 1.493% 0.000% 28,681 28,681 0 3.139% 16.521% 0.000%SC 10 5 5 1.217% 0.661% 7.692% 428,676 2,025 426,651 12.380% 0.252% 16.048%SD 2 1 1 0.851% 0.446% 9.091% 64,027 44 63,983 19.463% 0.019% 69.576%TN 3 1 2 0.857% 0.621% 1.058% 9,677 33 9,644 0.170% 0.002% 0.228%TX 10 10 0 0.205% 0.220% 0.000% 13,335 13,335 0 0.053% 0.144% 0.000%UT 1 1 0 0.197% 0.219% 0.000% 15,800 15,800 0 0.621% 0.937% 0.000%VA 2 2 0 0.126% 0.141% 0.000% 423 423 0 0.009% 0.067% 0.000%VT 2 2 0 0.334% 0.360% 0.000% 190 190 0 0.039% 0.084% 0.000%WI 14 13 1 0.768% 0.721% 5.000% 242,886 221,546 21,340 6.005% 9.417% 1.261%WV 23 17 6 5.111% 5.862% 3.750% 47,732 3,043 44,689 3.373% 1.297% 3.785%WY 3 2 1 0.987% 0.784% 2.041% 2,576 511 2,065 0.577% 0.396% 0.651%Total 274 223 51 0.561% 0.497% 1.276% 12,835,125 2,282,255 10,552,870 5.584% 2.669% 7.311%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A45. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 40 μg/L 30,291 0 0.000% 68,501,754 0 0.000%	
 30,291 0 0.000% 68,501,754 0 0.000%> 40 μg/L 3,130 0 0.000% 119,134,365 0 0.000%	
 3,130 0 0.000% 119,134,365 0 0.000%> 40 μg/L 33,421 0 0.000% 187,636,119 0 0.000%	
 33,421 0 0.000% 187,636,119 0 0.000%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A45a. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 104 53 51 0.000% 0.000% 0.000%AL 519 387 132 0.193% 0.000% 0.758% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1AR 1,664 1,423 241 0.240% 0.281% 0.000% 0.07 0.07 0.12 0.12 0.17 0.17 0.17 0.17AZ 6,919 5,460 1,459 0.000% 0.000% 0.000%CA 14,512 8,466 6,046 0.007% 0.012% 0.000% 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06CO 3,382 2,401 981 0.000% 0.000% 0.000%CT 1,601 1,015 586 0.437% 0.000% 1.195% 0.1 0.1 0.22 0.22 0.22 0.22 0.22 0.22DE 758 729 29 0.000% 0.000% 0.000%FL 2,396 2,329 67 0.459% 0.472% 0.000% 0.009 0.009 0.02 0.02 0.02 0.02 0.02 0.02GA 1,481 1,402 79 0.000% 0.000% 0.000%HI 2,101 2,004 97 0.000% 0.000% 0.000%IA 146 127 19 1.370% 0.000% 10.526% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2ID 1,978 1,710 268 0.000% 0.000% 0.000%IL 4,682 3,947 735 0.000% 0.000% 0.000%IN 2,251 2,086 165 0.000% 0.000% 0.000%KY 1,758 443 1,315 0.398% 0.000% 0.532% 0.0073 0.0073 0.31 0.31 0.5 0.5 0.5 0.5MA 3,023 2,236 787 0.165% 0.089% 0.381% 0.1 0.1 0.1 0.1 0.2 0.1 0.3 0.3 0.1 0.3 0.3 0.1MD 2,744 1,726 1,018 0.474% 0.232% 0.884% 0.16 0.6 0.16 0.6 0.8 0.48 0.8 0.8 1.1 1.1 0.8 1.1ME 456 391 65 0.000% 0.000% 0.000%MI 6,875 6,423 452 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 5,560 4,692 868 0.018% 0.021% 0.000% 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12MT 3,005 2,697 308 0.000% 0.000% 0.000%NC 13,610 12,474 1,136 0.007% 0.008% 0.000% 0.32 0.32 0.32 0.32 0.32 0.32 0.32 0.32ND 403 338 65 0.000% 0.000% 0.000%NE 4,480 4,131 349 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 39 33 6 0.000% 0.000% 0.000%NM 4,354 4,104 250 0.000% 0.000% 0.000%NV 1,639 1,199 440 0.000% 0.000% 0.000%NY 2,945 2,204 741 0.000% 0.000% 0.000%OH 674 437 237 0.000% 0.000% 0.000%OKOR 2,056 1,572 484 0.000% 0.000% 0.000%RI 922 630 292 0.108% 0.000% 0.342% 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14SC 2,966 2,572 394 0.000% 0.000% 0.000%SD 954 845 109 0.000% 0.000% 0.000%TN 65 12 53 0.000% 0.000% 0.000%TX 11,038 5,279 5,759 0.009% 0.000% 0.017% 0.28 0.28 0.28 0.28 0.28 0.28 0.28 0.28UT 7,113 5,925 1,188 0.000% 0.000% 0.000%VA 504 178 326 0.000% 0.000% 0.000%VT 1,315 1,112 203 0.076% 0.090% 0.000% 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05WI 3,185 3,092 93 0.000% 0.000% 0.000%WV 646 336 310 2.167% 2.381% 1.935% 0.03 0.03 0.03 0.04 0.035 0.1 0.5 0.07 0.5 0.5 0.07 0.5WY 1,291 964 327 0.077% 0.104% 0.000% 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62Total 137,068 108,078 28,990 0.052% 0.031% 0.128% 0.0073 0.009 0.0073 0.1 0.04 0.2 0.6 0.62 0.6 1.1 0.8 1.1

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A45b. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 16 10 6 246,416 14,306 232,110 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 175 130 45 2,737,924 625,336 2,112,588 0.571% 0.000% 2.222% 0.813% 0.000% 1.053%AR 450 379 71 2,447,627 905,863 1,541,764 0.667% 0.792% 0.000% 0.157% 0.424% 0.000%AZ 949 901 48 6,081,248 2,710,657 3,370,591 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CA 1,688 1,393 295 33,918,407 12,195,317 21,723,090 0.059% 0.072% 0.000% 0.147% 0.410% 0.000%CO 810 591 219 4,991,644 524,735 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 657 619 38 2,595,377 261,490 2,333,887 0.609% 0.000% 10.526% 17.133% 0.000% 19.052%DE 201 198 3 628,982 347,582 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,315 1,294 21 16,791,489 14,552,313 2,239,176 0.380% 0.386% 0.000% 15.509% 17.895% 0.000%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 112 100 12 1,305,882 1,251,254 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 98 94 4 305,037 99,579 205,458 2.041% 0.000% 50.000% 21.661% 0.000% 32.159%ID 784 733 51 1,036,541 793,942 242,599 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,371 1,267 104 9,186,700 2,986,303 6,200,397 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,402 1,358 44 4,866,349 2,546,613 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 2.058% 0.000% 3.333% 7.147% 0.000% 7.781%MA 645 528 117 8,485,498 1,683,116 6,802,382 0.620% 0.379% 1.709% 0.916% 1.076% 0.876%MD 862 794 68 4,906,096 907,989 3,998,107 1.160% 0.504% 8.824% 37.858% 0.031% 46.449%ME 269 241 28 510,420 134,500 375,920 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,935 2,874 61 7,227,231 2,047,375 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,471 1,395 76 2,644,644 1,700,183 944,461 0.068% 0.072% 0.000% 0.039% 0.060% 0.000%MT 813 753 60 753,259 360,590 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.042% 0.045% 0.000% 0.003% 0.012% 0.000%ND 207 180 27 559,051 253,826 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 35 30 5 1,380,103 143,223 1,236,880 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 695 659 36 1,662,962 1,400,064 262,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 291 270 21 960,972 271,081 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,348 1,117 231 4,924,821 981,544 3,943,277 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 285 205 80 6,558,119 518,824 6,039,295 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,085 935 150 2,937,414 572,664 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 105 97 8 902,560 163,122 739,438 0.952% 0.000% 12.500% 7.563% 0.000% 9.232%SC 773 714 59 3,427,802 801,019 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 12 6 6 655,614 145,112 510,502 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 0.050% 0.000% 0.297% 0.036% 0.000% 0.049%UT 427 390 37 2,500,736 1,667,550 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 442 409 33 432,910 181,746 251,164 0.226% 0.244% 0.000% 0.071% 0.169% 0.000%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 343 196 147 1,368,815 204,156 1,164,659 3.499% 4.082% 2.721% 0.946% 0.812% 0.970%WY 304 256 48 446,177 129,229 316,948 0.329% 0.391% 0.000% 0.101% 0.348% 0.000%Total 33,421 30,291 3,130 187,636,119 68,501,754 119,134,365 0.159% 0.089% 0.831% 2.956% 3.912% 2.406%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A45c. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 40 μg/L

State

Number of Systems 

with At Least One Detection 

> 40 μg/L

Percent of Systems 

with At Least One Detection 

> 40 μg/L

Population Served by Systems 

with At Least One Detection 

> 40 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A45d. Methoxychlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A46. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 100 μg/L 46,069 0 0.000% 85,149,817 0 0.000%

	
 46,069 0 0.000% 85,149,817 0 0.000%

> 100 μg/L 4,242 0 0.000% 140,477,965 0 0.000%

	
 4,242 0 0.000% 140,477,965 0 0.000%

> 100 μg/L 50,311 0 0.000% 225,627,782 0 0.000%

	
 50,311 0 0.000% 225,627,782 0 0.000%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A46a. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,184 2,046 1,138 0.031% 0.049% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5AL 820 596 224 0.122% 0.168% 0.000% 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6AR 2,394 1,926 468 0.376% 0.467% 0.000% 0.07 0.07 0.12 0.12 0.3 0.3 0.3 0.3AZ 11,717 9,527 2,190 0.026% 0.000% 0.137% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5CA 85,614 45,340 40,274 0.152% 0.282% 0.005% 0.5 0.5 0.52 0.8 0.8 0.59 2 2 0.66 13 13 0.66CO 2,863 2,124 739 0.175% 0.141% 0.271% 0.05 0.06 0.05 0.06 0.06 0.055 0.08 0.08 0.06 0.08 0.08 0.06CT 6,654 5,765 889 0.060% 0.069% 0.000% 0.5 0.5 0.6 0.6 2.5 2.5 2.5 2.5DE 1,048 1,018 30 0.000% 0.000% 0.000%FL 4,155 4,087 68 0.963% 0.979% 0.000% 0.08 0.08 0.78 0.78 1.745 1.745 3.7 3.7GA 7,175 6,348 827 0.000% 0.000% 0.000%HIIA 1,757 1,632 125 0.000% 0.000% 0.000%ID 3,750 3,289 461 0.000% 0.000% 0.000%IL 6,995 6,428 567 0.014% 0.016% 0.000% 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2IN 4,621 4,311 310 0.022% 0.000% 0.323% 9.7 9.7 9.7 9.7 9.7 9.7 9.7 9.7KY 3,310 1,126 2,184 0.332% 0.000% 0.504% 0.003 0.003 0.5 0.5 1.2 1.2 1.2 1.2MA 16,249 12,259 3,990 0.055% 0.057% 0.050% 0.66 0.66 0.8 15 17 0.9 42 42 1 42 42 1MD 6,768 5,508 1,260 0.044% 0.054% 0.000% 0.5 0.5 2.6 2.6 5.7 5.7 5.7 5.7ME 3,698 3,383 315 0.027% 0.030% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5MI 10,754 9,744 1,010 0.009% 0.000% 0.099% 16 16 16 16 16 16 16 16MN 8,581 7,332 1,249 0.047% 0.055% 0.000% 0.9 0.9 1.3 1.3 1.7 1.7 1.7 1.7MO 7,543 6,694 849 0.013% 0.015% 0.000% 4.4 4.4 4.4 4.4 4.4 4.4 4.4 4.4MT 4,490 3,952 538 0.022% 0.025% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5NC 19,064 17,485 1,579 0.142% 0.132% 0.253% 0.5 0.5 0.7 0.8 0.7 1.775 2 1.6 19.7 19.7 2 19.7ND 552 417 135 0.000% 0.000% 0.000%NE 6,840 6,264 576 0.058% 0.048% 0.174% 0.21 0.21 0.95 0.595 0.24 0.95 2.73 2.73 0.95 2.73 2.73 0.95NH 9,585 9,107 478 0.083% 0.088% 0.000% 0.5 0.5 0.515 0.515 0.65 0.65 0.65 0.65NJ 20,354 18,568 1,786 0.275% 0.178% 1.288% 0.05 0.05 0.1 0.8 0.56 1 1.6 1.05 1.7 4.14 4.14 2NM 6,575 6,099 476 0.015% 0.016% 0.000% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2NV 3,202 2,574 628 0.250% 0.311% 0.000% 0.5 0.5 0.935 0.935 1.69 1.69 1.69 1.69NY 7,076 5,420 1,656 0.099% 0.092% 0.121% 0.5 0.5 0.5 0.5 0.5 0.5 8.8 8.8 0.5 8.8 8.8 0.5OH 8,852 7,690 1,162 0.023% 0.013% 0.086% 0.5 1.06 0.5 0.78 1.06 0.5 1.06 1.06 0.5 1.06 1.06 0.5OK 5,355 3,958 1,397 0.037% 0.051% 0.000% 0.4 0.4 0.45 0.45 0.5 0.5 0.5 0.5OR 2,324 1,682 642 0.000% 0.000% 0.000%RI 1,959 1,591 368 0.000% 0.000% 0.000%SC 4,342 3,805 537 0.000% 0.000% 0.000%SD 889 855 34 0.000% 0.000% 0.000%TN 2,935 1,166 1,769 0.000% 0.000% 0.000%TX 34,144 27,040 7,104 0.009% 0.011% 0.000% 0.7 0.7 0.91 0.91 35 35 35 35UT 8,986 7,560 1,426 0.022% 0.026% 0.000% 19 19 19 19 19 19 19 19VA 4,909 4,038 871 0.081% 0.099% 0.000% 0.5 0.5 0.6 0.6 1.5 1.5 1.5 1.5VT 4,342 3,951 391 0.023% 0.025% 0.000% 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99WI 11,296 11,172 124 0.089% 0.090% 0.000% 0.02 0.02 0.255 0.255 0.58 0.58 0.61 0.61WV 1,139 444 695 1.229% 2.477% 0.432% 0.07 0.07 0.5 0.5 0.5 0.5 0.5 0.5 1 1 0.5 1WY 1,659 1,156 503 0.000% 0.000% 0.000%Total 370,519 286,477 84,042 0.101% 0.111% 0.067% 0.003 0.02 0.003 0.7 0.7 0.8 1.94 2 1.9 42 42 19.7

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A46b. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.161% 0.211% 0.000% 0.825% 2.150% 0.000%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.380% 0.495% 0.000% 0.149% 0.559% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 1.762% 2.094% 0.000% 0.598% 1.612% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.094% 0.000% 2.083% 4.865% 0.000% 8.901%CA 3,657 3,141 516 35,829,496 13,517,105 22,312,391 0.219% 0.191% 0.388% 1.538% 0.639% 2.082%CO 826 605 221 4,997,841 530,207 4,467,634 0.605% 0.496% 0.905% 0.413% 0.179% 0.441%CT 1,200 1,161 39 2,722,518 388,596 2,333,922 0.167% 0.172% 0.000% 0.029% 0.200% 0.000%DE 318 315 3 698,987 417,587 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,510 1,484 26 17,495,564 15,249,522 2,246,042 0.861% 0.876% 0.000% 3.641% 4.177% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.070% 0.075% 0.000% 0.017% 0.053% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.068% 0.000% 2.273% 5.388% 0.000% 11.360%KY 241 92 149 4,602,392 375,363 4,227,029 2.905% 0.000% 4.698% 9.116% 0.000% 9.925%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.696% 0.500% 1.695% 1.522% 0.421% 1.805%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.285% 0.304% 0.000% 0.589% 2.884% 0.000%ME 810 757 53 728,347 292,773 435,574 0.123% 0.132% 0.000% 0.030% 0.073% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.034% 0.000% 1.639% 0.135% 0.000% 0.187%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.190% 0.193% 0.000% 0.080% 0.113% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.071% 0.075% 0.000% 0.017% 0.030% 0.000%MT 848 788 60 757,949 365,280 392,669 0.118% 0.127% 0.000% 0.013% 0.026% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.465% 0.314% 2.878% 0.562% 0.048% 0.731%ND 210 183 27 562,397 257,172 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.519% 0.395% 9.091% 35.170% 0.304% 65.960%NH 1,258 1,217 41 948,788 398,989 549,799 0.159% 0.164% 0.000% 0.030% 0.071% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 1.144% 0.955% 8.108% 6.206% 7.449% 5.537%NM 726 687 39 1,698,755 1,432,207 266,548 0.138% 0.146% 0.000% 0.007% 0.008% 0.000%NV 338 317 21 973,592 283,701 689,891 0.592% 0.631% 0.000% 0.037% 0.127% 0.000%NY 1,517 1,283 234 4,884,210 1,042,143 3,842,067 0.461% 0.390% 0.855% 0.091% 0.395% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.103% 0.055% 0.800% 0.443% 0.004% 0.637%OK 718 506 212 3,119,686 660,832 2,458,854 0.139% 0.198% 0.000% 0.008% 0.038% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.061% 0.065% 0.000% 0.042% 0.113% 0.000%UT 500 454 46 2,553,197 1,698,877 854,320 0.200% 0.220% 0.000% 0.001% 0.002% 0.000%VA 1,597 1,426 171 5,271,968 629,385 4,642,583 0.188% 0.210% 0.000% 0.053% 0.445% 0.000%VT 603 560 43 491,035 227,067 263,968 0.166% 0.179% 0.000% 0.018% 0.040% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.224% 0.227% 0.000% 0.156% 0.268% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.193% 1.018% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,311 46,069 4,242 225,627,782 85,149,817 140,477,965 0.268% 0.228% 0.707% 1.564% 1.205% 1.782%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A46c. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 100 μg/L

State

Number of Systems 

with At Least One Detection 

> 100 μg/L

Percent of Systems 

with At Least One Detection 

> 100 μg/L

Population Served by Systems 

with At Least One Detection 

> 100 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A46d. Monochlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A47. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 10 mg/L 114,764 2,855 2.488% 92,900,757 5,278,260 5.682%

	
 114,764 10,742 9.360% 92,900,757 19,289,360 20.763%

> 10 mg/L 4,773 118 2.472% 136,607,279 11,498,833 8.417%

	
 4,773 368 7.710% 136,607,279 24,830,964 18.177%

> 10 mg/L 119,537 2,973 2.487% 229,508,036 16,777,093 7.310%

	
 119,537 11,110 9.294% 229,508,036 44,120,324 19.224%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A47a. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 10,435 8,920 1,515 46.909% 46.693% 48.185% 1E-06 1E-06 7.3E-05 0.57 0.62 0.32 3.37 3.8 1.39 15.7 15.7 14.7AL 6,717 5,735 982 51.764% 46.748% 81.059% 0.00016 0.00016 0.0008 0.53 0.51 0.58 2.4 2.44 2.34 55 55 7.79ARAZ 23,327 20,063 3,264 87.435% 87.769% 85.386% 0.0026 0.0026 0.0034 1.85 1.8 2.1 6.9 7.1 6.19 76 76 17CA 229,724 137,054 92,670 85.504% 84.806% 86.537% 0.0018 0.00226 0.0018 4.52 4.294 4.52 10.396 10.17 10.7576 94.92 94.92 39.776CO 11,861 9,486 2,375 71.604% 73.023% 65.937% 0.00121 0.00121 0.01 0.7 0.92 0.26 6.8 7.5 1.8 51 51 12.2CT 15,989 15,201 788 71.649% 71.252% 79.315% 9.3E-06 9.3E-06 0.003 1.62 1.7 0.85 5.4 5.5 3.5 26 26 8.76DE 5,415 5,337 78 66.242% 65.767% 98.718% 0.0022 0.0022 0.8 5.1 5.2 3.1 9.8 9.9 5.8 66.8 66.8 8.5FL 15,514 15,275 239 55.969% 55.417% 91.213% 0.001 0.001 0.002 0.5 0.52 0.31 4.6 4.66 0.9 40 40 1.7GA 313 310 3 49.840% 49.355% 100.000% 0.01 0.01 0.14 0.23 0.23 0.28 1.41 1.41 0.39 11 11 0.39HI 3,191 3,100 91 80.100% 81.871% 19.780% 0.3 0.3 0.33 1 1 0.79 4.7 4.7 1.9 6.8 6.8 2IA 27,727 26,586 1,141 66.094% 65.053% 90.359% 0.01 0.01 0.07 3.67 3.7 3.4 8.8 8.8 8.6 99 99 15ID 21,327 19,652 1,675 74.844% 76.435% 56.179% 0.0013 0.0013 0.00652 1.46 1.46 1.54 5.97 5.7 7.24 33.5 33.5 10.3IL 14,109 13,061 1,048 39.450% 35.319% 90.935% 0.0006 0.00082 0.0006 1.6 1.6 1.75 7.2 7.47 5.75 26.8 26.8 9.54IN 38,430 37,583 847 59.649% 58.997% 88.548% 0.0005 0.0005 0.005 0.5 0.5 1.15 4.8 4.85 4.145 83 83 9.2KY 3,852 1,361 2,491 79.958% 75.018% 82.658% 0.0007 0.001 0.0007 0.675 1.11 0.59 3.1 5.3 1.8 29 29 10MA 23,712 19,109 4,603 83.713% 81.558% 92.657% 0.005 0.008 0.005 0.84 0.97 0.67 4.4 4.9 1.5 33.25 33.25 9.32MD 36,120 33,598 2,522 56.166% 53.325% 94.013% 0.001 0.001 0.002 3.9 4.1 2.7 8.9 9 8.36 56.6 56.6 36.05ME 20,466 19,721 745 44.684% 45.485% 23.490% 0.00274 0.00274 0.01 1.04 1.06 0.5 4.21 4.26 1.38 23 23 5.52MI 97,673 96,866 807 40.045% 39.652% 87.237% 0.0062 0.0062 0.1 0.5 0.5 0.4 4.75 4.8 1.4 41.5 41.5 6.7MN 81,637 80,734 903 31.752% 31.554% 49.391% 0.01 0.01 0.05 0.96 0.98 0.35 6.7 6.7 3.3 45 45 17MO 24,401 23,508 893 0.086% 0.089% 0.000% 0.01 0.01 0.01 0.01 10.8 10.8 12.5 12.5MT 1,210 1,131 79 86.612% 86.561% 87.342% 0.01 0.01 0.01 0.47 0.5 0.12 1.94 2.02 0.94 81 81 1.79NC 55,468 53,861 1,607 47.766% 47.960% 41.257% 0.001 0.001 0.01 1.3 1.36 0.29 5.1 5.17 1 55.2 55.2 5.9ND 24 11 13 70.833% 36.364% 100.000% 0.03 0.04 0.03 0.09 0.805 0.07 1.51 1.79 0.23 1.79 1.79 1.02NE 31 31 0 74.194% 74.194% 0.000% 0.15 0.15 2.7 2.7 9.8 9.8 13.5 13.5NH 14,766 14,629 137 30.218% 30.234% 28.467% 0.01 0.01 0.12 0.69 0.7 0.5 5.15 5.16 1.96 21 21 2.81NJ 42,954 41,610 1,344 66.869% 66.486% 78.720% 0.001 0.001 0.009 2.1 2.19 1.2 6.5 6.6 3.85 39.6 39.6 8.83NM 375 359 16 52.800% 52.368% 62.500% 0.01 0.01 0.03 0.455 0.455 0.495 3.1 3.01 4.65 9.27 9.27 5.68NV 7,723 6,603 1,120 80.008% 80.433% 77.500% 0.0007 0.0007 0.05 1.01 1 1.02 4.1 4.4 2.83 31.1 31.1 8.05NY 32,231 29,172 3,059 61.444% 59.807% 77.051% 0.00018 0.00018 0.00067 0.97 1 0.6 5.29 5.4 4.27 52 52 48.5OH 43,957 32,489 11,468 49.091% 36.215% 85.569% 0.00005 0.00005 0.00149 0.86 0.83 0.88 5.44 5.46 5.4 50.4 50.4 21.7OK 2,270 2,047 223 84.009% 83.732% 86.547% 0.02 0.02 0.05 1.48 1.71 0.65 6.96 7.41 1.87 25.99 25.99 5.48OR 11,977 10,686 1,291 45.671% 46.472% 39.040% 0.00819 0.00819 0.01 1.3 1.42 0.6 5.5 5.7 2 28.5 28.5 6.57RI 6,011 5,653 358 82.948% 82.947% 82.961% 0.0015 0.0015 0.01 1.115 1.2 0.6 5 5.1 2.5 18.2 18.2 5.55SC 12,298 11,682 616 59.416% 58.594% 75.000% 0.003 0.003 0.02 0.52 0.56 0.32 3 3 1.1 61 61 6SD 342 317 25 83.333% 86.120% 48.000% 0.08 0.08 0.1 1.09 1.11 0.15 1.96 1.96 0.28 3.69 3.69 0.31TN 4,234 2,159 2,075 69.509% 50.672% 89.108% 0.01 0.01 0.05 0.66 0.74 0.63 2 2.4 1.8 8.7 7.7 8.7TX 32,726 28,612 4,114 79.301% 77.502% 91.808% 0.01 0.01 0.01 0.19 0.19 0.21 6.12 6.82 1.44 88 88 20.2UT 22,429 19,124 3,305 91.547% 90.959% 94.947% 0.01 0.01 0.02 0.6 0.6 0.5 2.6 2.6 2.3 15.2 15.2 5.85VA 362 314 48 69.890% 67.516% 85.417% 0.02 0.02 0.09 1.1 1.17 0.62 4.84 5.06 1.38 15 15 2.51VT 10,203 9,649 554 42.282% 42.284% 42.238% 0.00013 0.00013 0.004 0.7 0.7 0.3 2.6 2.7 1.1 20.6 20.6 4.6WI 32,001 31,850 151 59.189% 59.250% 46.358% 0.002 0.002 0.06 2.51 2.55 0.5 8.6 8.6 0.88 44 44 1.2WV 4,241 3,387 854 56.921% 51.225% 79.508% 0.00014 0.00275 0.00014 0.44 0.39 0.48 3.28 3.69 1.7 27.6 27.6 8.31WY 2,714 2,309 405 70.818% 73.798% 53.827% 0.01 0.01 0.01 0.7 0.8 0.315 6.3 6.87 3.2 32.1 32.1 9.7Total 1,052,487 899,945 152,542 61.385% 57.670% 83.304% 1E-06 1E-06 7.3E-05 1.8 1.6 2.712 7.91 7.5258 9.04 99 99 48.5

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A47b. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1,475 1,267 208 711,941 323,895 388,046 73.424% 73.402% 73.558% 80.836% 63.191% 95.565%AL 425 352 73 4,741,994 1,503,960 3,238,034 92.000% 90.625% 98.630% 98.101% 94.913% 99.582%ARAZ 1,656 1,596 60 6,292,367 2,918,171 3,374,196 95.350% 95.426% 93.333% 98.848% 97.549% 99.971%CA 7,384 6,628 756 38,517,529 15,274,342 23,243,187 73.267% 75.211% 56.217% 90.813% 92.446% 89.741%CO 1,744 1,432 312 5,256,456 715,725 4,540,731 82.626% 82.612% 82.692% 89.674% 90.041% 89.616%CT 2,914 2,872 42 2,786,657 452,660 2,333,997 82.739% 82.591% 92.857% 96.885% 90.857% 98.054%DE 580 577 3 778,333 496,933 281,400 56.724% 56.499% 100.000% 87.817% 80.918% 100.000%FL 6,256 6,230 26 18,864,052 16,618,010 2,246,042 65.074% 64.928% 100.000% 84.238% 82.108% 100.000%GA 153 151 2 55,522 52,826 2,696 45.098% 44.371% 100.000% 26.991% 23.265% 100.000%HI 115 103 12 1,309,687 1,255,059 54,628 79.130% 85.437% 25.000% 98.796% 99.587% 80.611%IA 1,896 1,856 40 2,653,095 1,537,413 1,115,682 69.937% 69.450% 92.500% 87.709% 79.196% 99.438%ID 1,954 1,885 69 1,206,328 949,165 257,163 89.304% 90.133% 66.667% 93.978% 94.163% 93.296%IL 3,800 3,682 118 9,589,450 3,386,733 6,202,717 35.474% 33.650% 92.373% 87.480% 67.663% 98.300%IN 5,330 5,272 58 5,489,766 3,128,079 2,361,687 89.024% 88.904% 100.000% 98.719% 97.753% 100.000%KY 297 141 156 4,609,304 380,950 4,228,354 97.306% 94.326% 100.000% 99.765% 97.157% 100.000%MA 1,693 1,572 121 8,738,206 1,927,163 6,811,043 93.444% 93.066% 98.347% 99.087% 98.863% 99.150%MD 4,091 4,006 85 5,276,313 1,277,699 3,998,614 63.994% 63.230% 100.000% 96.482% 85.472% 100.000%ME 2,255 2,181 74 950,021 509,330 440,691 61.552% 61.669% 58.108% 71.394% 73.407% 69.067%MI 14,441 14,371 70 8,678,174 3,493,788 5,184,386 70.134% 69.988% 100.000% 93.727% 84.420% 100.000%MN 9,399 9,293 106 4,892,585 3,640,124 1,252,461 48.665% 48.499% 63.208% 76.682% 68.718% 99.829%MO 2,681 2,595 86 4,337,423 1,857,310 2,480,113 0.634% 0.655% 0.000% 0.053% 0.123% 0.000%MT 484 463 21 365,667 217,895 147,772 89.050% 88.985% 90.476% 96.609% 95.524% 98.209%NC 6,550 6,411 139 7,350,067 2,084,901 5,265,166 80.534% 80.206% 95.683% 94.642% 91.410% 95.921%ND 12 6 6 25,377 18,348 7,029 75.000% 50.000% 100.000% 84.821% 79.006% 100.000%NE 16 16 0 16,071 16,071 0 87.500% 87.500% 0.000% 99.403% 99.403% 0.000%NH 2,159 2,139 20 746,993 520,719 226,274 50.533% 50.631% 40.000% 61.227% 62.338% 58.668%NJ 4,218 4,181 37 8,258,138 3,222,192 5,035,946 87.767% 87.682% 97.297% 96.841% 92.013% 99.930%NM 102 96 6 705,705 589,326 116,379 71.569% 69.792% 100.000% 98.468% 98.165% 100.000%NV 576 554 22 997,901 307,984 689,917 94.792% 95.487% 77.273% 97.033% 97.440% 96.852%NY 6,491 5,981 510 12,319,219 1,622,163 10,697,056 77.538% 76.710% 87.255% 93.531% 89.341% 94.167%OH 5,072 4,924 148 10,675,300 3,569,388 7,105,912 59.286% 58.123% 97.973% 93.794% 81.470% 99.985%OK 808 703 105 2,010,183 634,125 1,376,058 89.356% 89.900% 85.714% 91.060% 91.687% 90.772%OR 2,671 2,446 225 3,182,057 796,755 2,385,302 60.651% 60.180% 65.778% 85.106% 74.157% 88.763%RI 469 459 10 968,534 227,231 741,303 91.898% 91.721% 100.000% 99.407% 97.472% 100.000%SC 1,632 1,565 67 3,575,289 915,912 2,659,377 78.125% 77.188% 100.000% 96.973% 88.182% 100.000%SD 72 68 4 139,171 69,546 69,625 73.611% 72.059% 100.000% 94.694% 89.383% 100.000%TN 369 176 193 5,686,766 1,463,885 4,222,881 90.244% 81.250% 98.446% 96.775% 90.016% 99.119%TX 6,198 5,817 381 25,381,472 9,552,528 15,828,944 86.947% 86.230% 97.900% 97.280% 92.932% 99.904%UT 996 932 64 2,638,256 1,777,397 860,859 95.382% 95.386% 95.313% 99.627% 99.484% 99.924%VA 225 209 16 1,742,737 61,188 1,681,549 72.889% 70.813% 100.000% 99.205% 77.366% 100.000%VT 1,314 1,255 59 596,093 326,550 269,543 73.744% 73.466% 79.661% 71.139% 80.114% 60.266%WI 6,853 6,835 18 4,378,408 2,709,133 1,669,275 66.423% 66.379% 83.333% 87.687% 85.234% 91.668%WV 1,089 915 174 1,493,668 313,806 1,179,862 76.584% 72.568% 97.701% 96.637% 84.803% 99.785%WY 622 551 71 519,761 184,379 335,382 80.064% 81.125% 71.831% 91.736% 90.824% 92.238%Total 119,537 114,764 4,773 229,508,036 92,900,757 136,607,279 69.942% 69.466% 81.374% 90.952% 85.648% 94.559%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A47c. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 7 6 1 0.475% 0.474% 0.481% 1,973 1,789 184 0.277% 0.552% 0.047%AL 3 3 0 0.706% 0.852% 0.000% 9,709 9,709 0 0.205% 0.646% 0.000%ARAZ 105 102 3 6.341% 6.391% 5.000% 824,186 236,686 587,500 13.098% 8.111% 17.412%CA 639 574 65 8.654% 8.660% 8.598% 12,672,259 3,671,971 9,000,288 32.900% 24.040% 38.722%CO 41 39 2 2.351% 2.723% 0.641% 30,389 30,047 342 0.578% 4.198% 0.008%CT 20 20 0 0.686% 0.696% 0.000% 2,337 2,337 0 0.084% 0.516% 0.000%DE 51 51 0 8.793% 8.839% 0.000% 33,594 33,594 0 4.316% 6.760% 0.000%FL 19 19 0 0.304% 0.305% 0.000% 121,275 121,275 0 0.643% 0.730% 0.000%GA 1 1 0 0.654% 0.662% 0.000% 100 100 0 0.180% 0.189% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 114 109 5 6.013% 5.873% 12.500% 458,504 111,037 347,467 17.282% 7.222% 31.144%ID 47 46 1 2.405% 2.440% 1.449% 76,149 74,538 1,611 6.312% 7.853% 0.626%IL 74 74 0 1.947% 2.010% 0.000% 18,196 18,196 0 0.190% 0.537% 0.000%IN 163 163 0 3.058% 3.092% 0.000% 28,385 28,385 0 0.517% 0.907% 0.000%KY 3 3 0 1.010% 2.128% 0.000% 1,110 1,110 0 0.024% 0.291% 0.000%MA 33 33 0 1.949% 2.099% 0.000% 8,597 8,597 0 0.098% 0.446% 0.000%MD 225 220 5 5.500% 5.492% 5.882% 68,736 33,245 35,491 1.303% 2.602% 0.888%ME 32 32 0 1.419% 1.467% 0.000% 4,449 4,449 0 0.468% 0.874% 0.000%MI 203 203 0 1.406% 1.413% 0.000% 103,836 103,836 0 1.197% 2.972% 0.000%MN 235 234 1 2.500% 2.518% 0.943% 68,623 68,583 40 1.403% 1.884% 0.003%MO 1 1 0 0.037% 0.039% 0.000% 25 25 0 0.001% 0.001% 0.000%MT 2 2 0 0.413% 0.432% 0.000% 245 245 0 0.067% 0.112% 0.000%NC 66 66 0 1.008% 1.029% 0.000% 38,376 38,376 0 0.522% 1.841% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 12.500% 12.500% 0.000% 254 254 0 1.580% 1.580% 0.000%NH 14 14 0 0.648% 0.655% 0.000% 1,912 1,912 0 0.256% 0.367% 0.000%NJ 161 161 0 3.817% 3.851% 0.000% 67,792 67,792 0 0.821% 2.104% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 14 14 0 2.431% 2.527% 0.000% 3,979 3,979 0 0.399% 1.292% 0.000%NY 96 82 14 1.479% 1.371% 2.745% 190,619 22,532 168,087 1.547% 1.389% 1.571%OH 58 41 17 1.144% 0.833% 11.486% 1,352,964 19,661 1,333,303 12.674% 0.551% 18.763%OK 42 42 0 5.198% 5.974% 0.000% 30,307 30,307 0 1.508% 4.779% 0.000%OR 25 25 0 0.936% 1.022% 0.000% 21,245 21,245 0 0.668% 2.666% 0.000%RI 9 9 0 1.919% 1.961% 0.000% 1,835 1,835 0 0.189% 0.808% 0.000%SC 17 17 0 1.042% 1.086% 0.000% 5,064 5,064 0 0.142% 0.553% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 120 116 4 1.936% 1.994% 1.050% 397,138 372,618 24,520 1.565% 3.901% 0.155%UT 4 4 0 0.402% 0.429% 0.000% 1,643 1,643 0 0.062% 0.092% 0.000%VA 4 4 0 1.778% 1.914% 0.000% 586 586 0 0.034% 0.958% 0.000%VT 5 5 0 0.381% 0.398% 0.000% 779 779 0 0.131% 0.239% 0.000%WI 309 309 0 4.509% 4.521% 0.000% 120,396 120,396 0 2.750% 4.444% 0.000%WV 3 3 0 0.275% 0.328% 0.000% 3,087 3,087 0 0.207% 0.984% 0.000%WY 6 6 0 0.965% 1.089% 0.000% 6,440 6,440 0 1.239% 3.493% 0.000%Total 2,973 2,855 118 2.487% 2.488% 2.472% 16,777,093 5,278,260 11,498,833 7.310% 5.682% 8.417%

Percent of Population Served 

with At Least One Detection 

> 10 mg/L

State

Number of Systems 

with At Least One Detection 

> 10 mg/L

Percent of Systems 

with At Least One Detection 

> 10 mg/L

Population Served by Systems 

with At Least One Detection 

> 10 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A47d. Nitrate (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 50 48 2 3.390% 3.788% 0.962% 9,057 8,753 304 1.272% 2.702% 0.078%AL 18 16 2 4.235% 4.545% 2.740% 499,477 204,734 294,743 10.533% 13.613% 9.103%ARAZ 356 346 10 21.498% 21.679% 16.667% 4,857,024 1,758,792 3,098,232 77.189% 60.270% 91.821%CA 1,670 1,563 107 22.616% 23.582% 14.153% 20,804,101 8,729,361 12,074,740 54.012% 57.150% 51.950%CO 161 151 10 9.232% 10.545% 3.205% 554,601 116,384 438,217 10.551% 16.261% 9.651%CT 226 223 3 7.756% 7.765% 7.143% 575,636 81,581 494,055 20.657% 18.023% 21.168%DE 173 172 1 29.828% 29.809% 33.333% 324,205 288,075 36,130 41.654% 57.971% 12.839%FL 169 169 0 2.701% 2.713% 0.000% 2,635,228 2,635,228 0 13.970% 15.858% 0.000%GA 2 2 0 1.307% 1.325% 0.000% 298 298 0 0.537% 0.564% 0.000%HI 3 3 0 2.609% 2.913% 0.000% 178,447 178,447 0 13.625% 14.218% 0.000%IA 326 310 16 17.194% 16.703% 40.000% 1,052,262 362,351 689,911 39.662% 23.569% 61.838%ID 214 209 5 10.952% 11.088% 7.246% 377,376 169,761 207,615 31.283% 17.885% 80.733%IL 276 254 22 7.263% 6.898% 18.644% 925,962 311,249 614,713 9.656% 9.190% 9.910%IN 525 516 9 9.850% 9.788% 15.517% 772,147 391,303 380,844 14.065% 12.509% 16.126%KY 30 20 10 10.101% 14.184% 6.410% 303,439 78,712 224,727 6.583% 20.662% 5.315%MA 178 167 11 10.514% 10.623% 9.091% 544,483 326,312 218,171 6.231% 16.932% 3.203%MD 989 963 26 24.175% 24.039% 30.588% 2,098,269 199,022 1,899,247 39.768% 15.577% 47.498%ME 126 125 1 5.588% 5.731% 1.351% 25,622 25,382 240 2.697% 4.983% 0.054%MI 773 771 2 5.353% 5.365% 2.857% 188,139 183,571 4,568 2.168% 5.254% 0.088%MN 740 733 7 7.873% 7.888% 6.604% 238,840 191,016 47,824 4.882% 5.248% 3.818%MO 1 1 0 0.037% 0.039% 0.000% 25 25 0 0.001% 0.001% 0.000%MT 14 14 0 2.893% 3.024% 0.000% 2,496 2,496 0 0.683% 1.146% 0.000%NC 415 414 1 6.336% 6.458% 0.719% 183,465 183,386 79 2.496% 8.796% 0.002%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 4 4 0 25.000% 25.000% 0.000% 824 824 0 5.127% 5.127% 0.000%NH 61 61 0 2.825% 2.852% 0.000% 9,851 9,851 0 1.319% 1.892% 0.000%NJ 750 747 3 17.781% 17.867% 8.108% 1,314,286 633,553 680,733 15.915% 19.662% 13.517%NM 7 6 1 6.863% 6.250% 16.667% 73,300 599 72,701 10.387% 0.102% 62.469%NV 70 69 1 12.153% 12.455% 4.545% 100,310 43,810 56,500 10.052% 14.225% 8.189%NY 480 432 48 7.395% 7.223% 9.412% 429,465 169,896 259,569 3.486% 10.473% 2.427%OH 245 205 40 4.830% 4.163% 27.027% 2,347,748 143,320 2,204,428 21.992% 4.015% 31.022%OK 177 176 1 21.906% 25.036% 0.952% 192,596 192,469 127 9.581% 30.352% 0.009%OR 162 159 3 6.065% 6.500% 1.333% 102,735 87,075 15,660 3.229% 10.929% 0.657%RI 42 41 1 8.955% 8.932% 10.000% 176,320 72,404 103,916 18.205% 31.864% 14.018%SC 84 82 2 5.147% 5.240% 2.985% 36,275 27,095 9,180 1.015% 2.958% 0.345%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 10 5 5 2.710% 2.841% 2.591% 86,781 6,380 80,401 1.526% 0.436% 1.904%TX 324 313 11 5.227% 5.381% 2.887% 841,164 553,205 287,959 3.314% 5.791% 1.819%UT 58 55 3 5.823% 5.901% 4.688% 739,205 405,855 333,350 28.019% 22.834% 38.723%VA 14 14 0 6.222% 6.699% 0.000% 2,189 2,189 0 0.126% 3.577% 0.000%VT 26 26 0 1.979% 2.072% 0.000% 3,508 3,508 0 0.588% 1.074% 0.000%WI 1,096 1,096 0 15.993% 16.035% 0.000% 479,285 479,285 0 10.947% 17.691% 0.000%WV 34 31 3 3.122% 3.388% 1.724% 21,391 19,341 2,050 1.432% 6.163% 0.174%WY 31 30 1 4.984% 5.445% 1.408% 12,492 12,462 30 2.403% 6.759% 0.009%Total 11,110 10,742 368 9.294% 9.360% 7.710% 44,120,324 19,289,360 24,830,964 19.224% 20.763% 18.177%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A48. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 1 mg/L 82,738 584 0.706% 81,271,403 729,751 0.898%

	
 82,738 1,241 1.500% 81,271,403 4,915,364 6.048%

> 1 mg/L 3,575 51 1.427% 126,713,410 9,337,280 7.369%

	
 3,575 112 3.133% 126,713,410 21,530,847 16.992%

> 1 mg/L 86,313 635 0.736% 207,984,813 10,067,031 4.840%

	
 86,313 1,353 1.568% 207,984,813 26,446,211 12.715%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A48a. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 1,142 862 280 3.327% 3.712% 2.143% 0.001 0.001 0.02 0.075 0.07 0.28 0.65 0.65 0.5 4.64 4.64 0.5AL 2,879 2,027 852 3.925% 3.503% 4.930% 0.002 0.002 0.003 0.03 0.02 0.045 0.3 0.25 0.36 2.03 2.03 2.03ARAZ 13,349 11,013 2,336 1.671% 1.780% 1.156% 0.004 0.004 0.006 0.05 0.055 0.05 0.48 0.52 0.3 5.8 5.8 0.5CA 61,630 39,623 22,007 3.060% 4.013% 1.345% 1E-06 1E-06 2E-06 0.004 0.003 0.03 0.34 0.2 0.5 7.31 6.1 7.31CO 5,507 4,368 1,139 2.760% 2.930% 2.107% 0.002 0.002 0.002 0.03 0.06 0.015 0.56 0.58 0.27 3.51 3.51 0.64CT 15,902 15,115 787 15.042% 15.250% 11.055% 0.0001 0.0001 0.002 0.01 0.01 0.01 0.1 0.1 0.05 3.44 3.44 1.09DE 1,655 1,615 40 1.148% 1.115% 2.500% 0.03 0.05 0.03 0.1 0.1 0.03 2.4 2.4 0.03 6.1 6.1 0.03FL 15,279 15,040 239 10.393% 9.801% 47.699% 0.001 0.001 0.001 0.01 0.01 0.02 0.17 0.16 0.29 2.3 2.3 1.17GA 100 98 2 3.000% 3.061% 0.000% 0.06 0.06 0.07 0.07 0.3 0.3 0.3 0.3HI 3,191 3,100 91 0.000% 0.000% 0.000%IA 3,909 3,817 92 17.268% 17.448% 9.783% 0.0003 0.0003 0.02 0.2 0.2 0.02 0.7 0.7 0.7 4 4 0.7ID 4,604 4,209 395 5.778% 6.296% 0.253% 0.002 0.002 0.01 0.009 0.009 0.01 0.14 0.14 0.01 2.1 2.1 0.01IL 12,758 12,190 568 4.264% 4.405% 1.232% 0.007 0.01 0.007 0.32 0.32 0.2 1.12 1.12 0.46 2.2 2.2 0.46IN 3,892 3,738 154 38.849% 38.604% 44.805% 0.0007 0.0007 0.001 0.05 0.05 0.005 0.1 0.1 0.05 5.6 5.6 0.14KY 2,980 958 2,022 7.886% 9.395% 7.171% 0.0001 0.0001 0.002 0.01 0.01 0.02 0.1 0.08 0.1 5 1 5MA 8,618 6,056 2,562 20.144% 15.258% 31.694% 0.0004 0.0004 0.004 0.02 0.01 0.03 0.09 0.05 0.12 5 2.28 5MD 6,993 6,491 502 15.301% 13.326% 40.837% 0.001 0.001 0.001 0.005 0.005 0.009 0.175 0.2 0.02 13 13 8.1ME 10,450 9,894 556 3.330% 3.275% 4.317% 0.008 0.008 0.01 0.01 0.01 0.01 0.07 0.07 0.05 1.2 1.2 0.1MI 76,978 76,172 806 26.900% 26.935% 23.573% 0.0023 0.0023 0.01 0.01 0.01 0.01 0.03 0.03 0.025 9.49 9.49 0.91MN 3,053 3,014 39 12.152% 12.309% 0.000% 0.001 0.001 0.02 0.02 0.27 0.27 2.1 2.1MO 12,519 12,068 451 46.945% 45.956% 73.392% 0.01 0.01 0.05 0.31 0.3 0.32 1.89 1.88 2.25 9.94 9.94 8.68MT 1,249 1,171 78 3.843% 3.928% 2.564% 0.01 0.01 0.01 0.035 0.04 0.01 1.69 1.69 0.01 2.39 2.39 0.01NC 9,024 8,603 421 4.588% 4.719% 1.900% 0.002 0.002 0.01 0.02 0.02 0.045 0.24 0.23 0.27 4.1 4.1 0.27ND 22 10 12 54.545% 20.000% 83.333% 0.03 0.04 0.03 0.08 0.07 0.08 0.17 0.1 0.2 0.23 0.1 0.23NE 18 18 0 0.000% 0.000% 0.000%NH 17,114 16,580 534 0.801% 0.820% 0.187% 0.001 0.001 0.59 0.1 0.1 0.59 0.64 0.64 0.59 1.17 1.17 0.59NJ 8,331 7,246 1,085 6.926% 7.439% 3.502% 0.0003 0.0003 0.004 0.01 0.01 0.02 0.14 0.14 0.17 5.4 5.4 0.53NM 1,055 985 70 1.611% 1.726% 0.000% 0.01 0.01 0.11 0.11 3.99 3.99 3.99 3.99NV 3,421 2,823 598 2.426% 2.515% 2.007% 0.01 0.01 0.01 0.09 0.09 0.075 0.5 0.61 0.24 2.2 2.2 0.27NY 7,166 6,448 718 5.261% 4.777% 9.610% 0.00001 0.00001 0.005 0.04 0.04 0.02 0.99 1 0.37 9.87 9.87 7.6OH 37,022 29,534 7,488 0.500% 0.582% 0.174% 0.00014 0.00014 0.05 0.11 0.1 0.19 0.38 0.38 0.4 1.15 1.15 0.48OK 1,783 1,591 192 6.169% 6.411% 4.167% 0.05 0.05 0.05 0.06 0.06 0.06 0.11 0.11 0.07 0.69 0.69 0.07OR 1,699 1,297 402 1.413% 1.696% 0.498% 0.004 0.004 0.1 0.04 0.035 0.35 0.3 0.28 0.6 1.5 1.5 0.6RI 5,601 5,242 359 2.999% 3.052% 2.228% 0.005 0.005 0.02 0.03 0.03 0.02 0.09 0.09 0.03 0.54 0.54 0.03SC 1,993 1,895 98 2.408% 2.375% 3.061% 0.02 0.02 0.02 0.03 0.03 0.03 0.11 0.11 0.03 0.73 0.73 0.03SD 380 366 14 4.737% 4.918% 0.000% 0.02 0.02 0.07 0.07 0.4 0.4 0.4 0.4TN 427 229 198 3.747% 4.803% 2.525% 0.01 0.01 0.01 0.02 0.02 0.02 0.1 0.1 0.05 0.15 0.15 0.05TX 7,373 6,132 1,241 16.805% 15.248% 24.496% 0.01 0.01 0.01 0.02 0.02 0.02 0.22 0.22 0.17 1.88 1.88 1.56UT 11,119 9,322 1,797 38.789% 41.525% 24.597% 0.01 0.01 0.01 0.26 0.27 0.2 0.62 0.62 0.66 7.75 7.75 2.8VA 281 246 35 7.117% 6.911% 8.571% 0.001 0.001 0.01 0.09 0.1 0.05 0.59 0.68 0.5 0.83 0.83 0.5VT 1,845 1,801 44 4.065% 4.109% 2.273% 0.002 0.002 0.05 0.02 0.02 0.05 0.12 0.12 0.05 0.66 0.66 0.05WI 9,603 9,428 175 12.517% 12.548% 10.857% 0.001 0.001 0.007 0.01 0.01 0.01 0.19 0.19 0.2 2.4 2.4 0.2WV 1,025 916 109 8.390% 8.297% 9.174% 0.003 0.003 0.01 0.05 0.05 0.125 0.77 0.77 0.74 4.67 4.67 1.05WY 2,236 1,855 381 8.274% 9.003% 4.724% 0.007 0.007 0.009 0.2 0.2 0.125 0.45 0.47 0.33 1.1 1.1 0.36Total 397,175 345,206 51,969 12.365% 13.251% 6.477% 1E-06 1E-06 2E-06 0.02 0.02 0.03 0.4 0.4 0.45 13 13 8.68

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A48b. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 696 574 122 454,495 154,431 300,064 5.316% 5.401% 4.918% 1.793% 3.350% 0.991%AL 372 299 73 4,730,976 1,492,942 3,238,034 18.011% 15.385% 28.767% 36.410% 20.014% 43.969%ARAZ 1,554 1,495 59 6,270,215 2,896,223 3,373,992 9.781% 9.097% 27.119% 61.943% 37.184% 83.196%CA 5,848 5,158 690 37,944,827 14,925,008 23,019,819 5.797% 5.409% 8.696% 40.388% 35.422% 43.607%CO 1,337 1,092 245 4,514,859 606,463 3,908,396 9.200% 9.615% 7.347% 15.075% 9.211% 15.985%CT 2,914 2,872 42 2,786,657 452,660 2,333,997 29.822% 29.666% 40.476% 47.380% 31.292% 50.501%DE 471 468 3 739,114 457,714 281,400 2.972% 2.778% 33.333% 22.971% 6.507% 49.751%FL 6,255 6,229 26 18,740,484 16,494,442 2,246,042 15.172% 14.962% 65.385% 49.287% 50.043% 43.736%GA 58 57 1 39,440 36,769 2,671 5.172% 5.263% 0.000% 0.231% 0.247% 0.000%HI 115 103 12 1,309,687 1,255,059 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 987 966 21 1,597,084 706,789 890,295 12.563% 12.526% 14.286% 19.760% 19.042% 20.330%ID 1,595 1,537 58 1,141,810 887,213 254,597 10.972% 11.321% 1.724% 13.402% 15.664% 5.519%IL 3,710 3,593 117 9,533,963 3,348,644 6,185,319 3.639% 3.590% 5.128% 4.358% 11.051% 0.735%IN 2,240 2,218 22 3,407,638 1,613,340 1,794,298 49.152% 49.188% 45.455% 47.527% 59.771% 36.519%KY 294 139 155 4,608,962 380,728 4,228,234 44.898% 37.410% 51.613% 60.117% 26.099% 63.180%MA 1,618 1,500 118 8,656,220 1,919,553 6,736,667 30.532% 30.067% 36.441% 67.478% 48.304% 72.942%MD 3,026 2,967 59 4,890,003 1,005,870 3,884,133 20.489% 19.953% 47.458% 76.067% 16.094% 91.598%ME 2,122 2,048 74 932,430 491,739 440,691 10.697% 10.498% 16.216% 16.172% 17.170% 15.059%MI 13,403 13,333 70 8,557,544 3,373,158 5,184,386 58.875% 58.756% 81.429% 87.342% 77.358% 93.838%MN 2,393 2,360 33 1,690,318 1,653,867 36,451 12.787% 12.966% 0.000% 16.859% 17.231% 0.000%MO 2,612 2,527 85 4,323,075 1,843,168 2,479,907 57.274% 56.074% 92.941% 77.989% 49.197% 99.389%MT 492 471 21 372,908 225,136 147,772 7.927% 8.068% 4.762% 6.858% 11.301% 0.088%NC 4,927 4,836 91 5,676,016 1,402,478 4,273,538 7.489% 7.486% 7.692% 9.128% 20.793% 5.300%ND 12 6 6 25,377 18,348 7,029 58.333% 33.333% 83.333% 31.690% 15.239% 74.634%NE 11 11 0 15,414 15,414 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 2,630 2,589 41 1,281,333 731,534 549,799 3.004% 3.013% 2.439% 3.277% 5.673% 0.087%NJ 1,911 1,877 34 7,167,350 2,454,112 4,713,238 14.966% 14.598% 35.294% 55.856% 28.781% 69.954%NM 544 522 22 1,432,779 1,241,815 190,964 3.125% 3.257% 0.000% 8.100% 9.346% 0.000%NV 566 544 22 997,503 307,586 689,917 9.541% 9.007% 22.727% 71.444% 16.989% 95.721%NY 2,386 2,208 178 9,658,089 590,778 9,067,311 12.028% 11.005% 24.719% 75.311% 14.517% 79.272%OH 5,053 4,906 147 10,672,352 3,566,540 7,105,812 3.028% 2.915% 6.803% 3.008% 3.367% 2.828%OK 787 691 96 1,948,185 623,862 1,324,323 11.563% 12.012% 8.333% 6.261% 12.822% 3.170%OR 989 853 136 2,855,851 519,515 2,336,336 2.224% 2.345% 1.471% 2.644% 11.102% 0.764%RI 469 459 10 968,534 227,231 741,303 14.072% 13.508% 40.000% 26.731% 15.246% 30.251%SC 1,141 1,088 53 3,200,533 691,636 2,508,897 3.330% 3.309% 3.774% 2.174% 0.664% 2.590%SD 300 289 11 334,779 202,039 132,740 5.667% 5.882% 0.000% 4.419% 7.323% 0.000%TN 84 52 32 2,349,183 1,014,599 1,334,584 5.952% 5.769% 6.250% 17.790% 0.027% 31.294%TX 3,673 3,333 340 22,322,690 6,694,172 15,628,518 20.120% 17.612% 44.706% 68.120% 52.194% 74.941%UT 947 884 63 2,608,294 1,747,635 860,659 70.116% 69.118% 84.127% 89.438% 85.521% 97.393%VA 177 165 12 1,899,919 51,267 1,848,652 9.605% 9.091% 16.667% 39.325% 8.848% 40.171%VT 800 777 23 209,994 157,872 52,122 8.000% 8.108% 4.348% 14.001% 18.567% 0.173%WI 3,751 3,731 20 4,182,062 2,490,318 1,691,744 21.354% 21.094% 70.000% 42.046% 48.058% 33.196%WV 451 390 61 423,068 124,414 298,654 16.630% 16.667% 16.393% 20.606% 21.382% 20.282%WY 592 521 71 512,799 177,322 335,477 20.101% 19.962% 21.127% 36.868% 37.750% 36.402%Total 86,313 82,738 3,575 207,984,813 81,271,403 126,713,410 22.318% 22.285% 23.077% 44.615% 36.640% 49.731%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A48c. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 3 3 0 0.431% 0.523% 0.000% 295 295 0 0.065% 0.191% 0.000%AL 3 1 2 0.806% 0.334% 2.740% 671,155 9,321 661,834 14.186% 0.624% 20.439%ARAZ 5 5 0 0.322% 0.334% 0.000% 32,937 32,937 0 0.525% 1.137% 0.000%CA 18 14 4 0.308% 0.271% 0.580% 4,624,393 120,741 4,503,652 12.187% 0.809% 19.564%CO 3 3 0 0.224% 0.275% 0.000% 626 626 0 0.014% 0.103% 0.000%CT 8 6 2 0.275% 0.209% 4.762% 40,363 2,215 38,148 1.448% 0.489% 1.634%DE 4 4 0 0.849% 0.855% 0.000% 11,262 11,262 0 1.524% 2.460% 0.000%FL 6 3 3 0.096% 0.048% 11.538% 142,645 588 142,057 0.761% 0.004% 6.325%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 14 14 0 1.418% 1.449% 0.000% 22,956 22,956 0 1.437% 3.248% 0.000%ID 4 4 0 0.251% 0.260% 0.000% 185 185 0 0.016% 0.021% 0.000%IL 12 12 0 0.323% 0.334% 0.000% 6,435 6,435 0 0.067% 0.192% 0.000%IN 7 7 0 0.313% 0.316% 0.000% 2,152 2,152 0 0.063% 0.133% 0.000%KY 2 0 2 0.680% 0.000% 1.290% 50,976 0 50,976 1.106% 0.000% 1.206%MA 5 3 2 0.309% 0.200% 1.695% 78,781 32,715 46,066 0.910% 1.704% 0.684%MD 19 17 2 0.628% 0.573% 3.390% 1,712,779 2,737 1,710,042 35.026% 0.272% 44.026%ME 1 1 0 0.047% 0.049% 0.000% 85 85 0 0.009% 0.017% 0.000%MI 25 25 0 0.187% 0.188% 0.000% 3,125 3,125 0 0.037% 0.093% 0.000%MN 4 4 0 0.167% 0.169% 0.000% 2,292 2,292 0 0.136% 0.139% 0.000%MO 355 338 17 13.591% 13.376% 20.000% 771,834 134,534 637,300 17.854% 7.299% 25.699%MT 3 3 0 0.610% 0.637% 0.000% 2,343 2,343 0 0.628% 1.041% 0.000%NC 4 4 0 0.081% 0.083% 0.000% 1,495 1,495 0 0.026% 0.107% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 2 2 0 0.076% 0.077% 0.000% 1,350 1,350 0 0.105% 0.185% 0.000%NJ 4 4 0 0.209% 0.213% 0.000% 12,800 12,800 0 0.179% 0.522% 0.000%NM 3 3 0 0.551% 0.575% 0.000% 410 410 0 0.029% 0.033% 0.000%NV 3 3 0 0.530% 0.551% 0.000% 765 765 0 0.077% 0.249% 0.000%NY 29 26 3 1.215% 1.178% 1.685% 4,247 4,149 98 0.044% 0.702% 0.001%OH 2 2 0 0.040% 0.041% 0.000% 1,517 1,517 0 0.014% 0.043% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 1 1 0 0.101% 0.117% 0.000% 175 175 0 0.006% 0.034% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 14 9 5 0.381% 0.270% 1.471% 1,133,205 42,897 1,090,308 5.076% 0.641% 6.976%UT 60 52 8 6.336% 5.882% 12.698% 690,018 241,972 448,046 26.455% 13.846% 52.058%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 7 7 0 0.187% 0.188% 0.000% 28,254 28,254 0 0.676% 1.135% 0.000%WV 4 3 1 0.887% 0.769% 1.639% 15,086 6,333 8,753 3.566% 5.090% 2.931%WY 1 1 0 0.169% 0.192% 0.000% 90 90 0 0.018% 0.051% 0.000%Total 635 584 51 0.736% 0.706% 1.427% 10,067,031 729,751 9,337,280 4.840% 0.898% 7.369%

Percent of Population Served 

with At Least One Detection 

> 1 mg/L

State

Number of Systems 

with At Least One Detection 

> 1 mg/L

Percent of Systems 

with At Least One Detection 

> 1 mg/L

Population Served by Systems 

with At Least One Detection 

> 1 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A48d. Nitrite (as N) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 7 5 2 1.006% 0.871% 1.639% 2,574 2,335 239 0.566% 1.512% 0.080%AL 7 3 4 1.882% 1.003% 5.479% 753,676 25,899 727,777 15.931% 1.735% 22.476%ARAZ 17 16 1 1.094% 1.070% 1.695% 63,508 63,368 140 1.013% 2.188% 0.004%CA 52 39 13 0.889% 0.756% 1.884% 5,826,393 575,592 5,250,801 15.355% 3.857% 22.810%CO 18 16 2 1.346% 1.465% 0.816% 68,287 4,484 63,803 1.512% 0.739% 1.632%CT 26 24 2 0.892% 0.836% 4.762% 43,345 5,197 38,148 1.555% 1.148% 1.634%DE 5 5 0 1.062% 1.068% 0.000% 13,262 13,262 0 1.794% 2.897% 0.000%FL 28 24 4 0.448% 0.385% 15.385% 2,953,977 2,569,796 384,181 15.763% 15.580% 17.105%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 27 26 1 2.736% 2.692% 4.762% 57,571 56,999 572 3.605% 8.065% 0.064%ID 10 10 0 0.627% 0.651% 0.000% 580 580 0 0.051% 0.065% 0.000%IL 30 30 0 0.809% 0.835% 0.000% 35,425 35,425 0 0.372% 1.058% 0.000%IN 13 13 0 0.580% 0.586% 0.000% 4,423 4,423 0 0.130% 0.274% 0.000%KY 6 2 4 2.041% 1.439% 2.581% 58,822 1,342 57,480 1.276% 0.352% 1.359%MA 9 6 3 0.556% 0.400% 2.542% 198,422 50,976 147,446 2.292% 2.656% 2.189%MD 29 26 3 0.958% 0.876% 5.085% 3,423,814 3,772 3,420,042 70.017% 0.375% 88.052%ME 3 3 0 0.141% 0.146% 0.000% 1,630 1,630 0 0.175% 0.331% 0.000%MI 61 60 1 0.455% 0.450% 1.429% 44,972 39,487 5,485 0.526% 1.171% 0.106%MN 4 4 0 0.167% 0.169% 0.000% 2,292 2,292 0 0.136% 0.139% 0.000%MO 616 584 32 23.583% 23.110% 37.647% 2,339,658 302,964 2,036,694 54.120% 16.437% 82.128%MT 5 5 0 1.016% 1.062% 0.000% 3,168 3,168 0 0.850% 1.407% 0.000%NC 19 19 0 0.386% 0.393% 0.000% 4,629 4,629 0 0.082% 0.330% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 11 10 1 0.418% 0.386% 2.439% 3,147 2,667 480 0.246% 0.365% 0.087%NJ 16 15 1 0.837% 0.799% 2.941% 797,792 121,538 676,254 11.131% 4.952% 14.348%NM 4 4 0 0.735% 0.766% 0.000% 510 510 0 0.036% 0.041% 0.000%NV 9 9 0 1.590% 1.654% 0.000% 17,412 17,412 0 1.746% 5.661% 0.000%NY 53 48 5 2.221% 2.174% 2.809% 6,812,556 7,179 6,805,377 70.537% 1.215% 75.054%OH 6 6 0 0.119% 0.122% 0.000% 5,137 5,137 0 0.048% 0.144% 0.000%OK 1 1 0 0.127% 0.145% 0.000% 432 432 0 0.022% 0.069% 0.000%OR 2 1 1 0.202% 0.117% 0.735% 6,875 175 6,700 0.241% 0.034% 0.287%RI 1 1 0 0.213% 0.218% 0.000% 150 150 0 0.015% 0.066% 0.000%SC 1 1 0 0.088% 0.092% 0.000% 36 36 0 0.001% 0.005% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 38 26 12 1.035% 0.780% 3.529% 1,633,073 265,724 1,367,349 7.316% 3.969% 8.749%UT 179 161 18 18.902% 18.213% 28.571% 1,185,969 659,143 526,826 45.469% 37.716% 61.212%VA 2 1 1 1.130% 0.606% 8.333% 6,325 25 6,300 0.333% 0.049% 0.341%VT 3 3 0 0.375% 0.386% 0.000% 285 285 0 0.136% 0.181% 0.000%WI 20 20 0 0.533% 0.536% 0.000% 49,027 49,027 0 1.172% 1.969% 0.000%WV 10 9 1 2.217% 2.308% 1.639% 25,152 16,399 8,753 5.945% 13.181% 2.931%WY 5 5 0 0.845% 0.960% 0.000% 1,905 1,905 0 0.371% 1.074% 0.000%Total 1,353 1,241 112 1.568% 1.500% 3.133% 26,446,211 4,915,364 21,530,847 12.715% 6.048% 16.992%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A49. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 200 μg/L 28,100 0 0.000% 61,701,854 0 0.000%

	
 28,100 0 0.000% 61,701,854 0 0.000%

> 2 μg/L 28,100 14 0.050% 61,701,854 38,142 0.062%

> 200 μg/L 2,776 1 0.036% 105,676,577 200 0.000%

	
 2,776 1 0.036% 105,676,577 200 0.000%

> 2 μg/L 2,776 4 0.144% 105,676,577 258,348 0.244%

> 200 μg/L 30,876 1 0.003% 167,378,431 200 0.000%

	
 30,876 1 0.003% 167,378,431 200 0.000%

> 2 μg/L 30,876 18 0.058% 167,378,431 296,490 0.177%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A49a. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 32 14 18 0.000% 0.000% 0.000%AL 503 374 129 0.000% 0.000% 0.000%AR 1,544 1,318 226 0.000% 0.000% 0.000%AZ 6,376 4,952 1,424 0.125% 0.141% 0.070% 0.5 0.5 0.5 0.5 0.5 0.5 2 2 0.5 2 2 0.5CA 12,095 6,951 5,144 0.008% 0.000% 0.019% 531.1 531.1 531.1 531.1 531.1 531.1 531.1 531.1CO 2,375 1,709 666 0.000% 0.000% 0.000%CT 1,310 1,001 309 0.992% 1.299% 0.000% 1 1 1 1 1 1 1 1DE 1,248 1,218 30 0.481% 0.493% 0.000% 0.53 0.53 0.53 0.53 0.53 0.53 0.53 0.53FL 2,360 2,295 65 0.636% 0.654% 0.000% 0.18 0.18 0.5 0.5 4 4 4 4GA 1,428 1,355 73 0.000% 0.000% 0.000%HI 1,694 1,646 48 0.000% 0.000% 0.000%IA 49 32 17 0.000% 0.000% 0.000%ID 1,177 965 212 0.000% 0.000% 0.000%IL 3,013 2,624 389 0.000% 0.000% 0.000%IN 2,241 2,081 160 0.000% 0.000% 0.000%KY 1,743 441 1,302 0.459% 0.000% 0.614% 1.28 1.28 2 2 2.6 2.6 2.6 2.6MA 2,922 2,157 765 0.000% 0.000% 0.000%MD 2,355 1,632 723 0.679% 0.797% 0.415% 2 5 2 5 5 2 5 5 2 5 5 2ME 357 300 57 0.000% 0.000% 0.000%MI 6,607 6,340 267 0.000% 0.000% 0.000%MN 4,577 4,443 134 0.000% 0.000% 0.000%MO 4,610 4,040 570 0.000% 0.000% 0.000%MT 2,851 2,583 268 0.035% 0.039% 0.000% 3.3 3.3 3.3 3.3 3.3 3.3 3.3 3.3NC 12,775 11,736 1,039 0.008% 0.009% 0.000% 5.01 5.01 5.01 5.01 5.01 5.01 5.01 5.01ND 60 41 19 0.000% 0.000% 0.000%NE 2,345 2,279 66 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 158 145 13 0.000% 0.000% 0.000%NM 4,260 4,011 249 0.047% 0.050% 0.000% 1.5 1.5 1.6 1.6 1.7 1.7 1.7 1.7NV 1,535 1,144 391 0.000% 0.000% 0.000%NY 2,866 2,154 712 0.070% 0.093% 0.000% 0.5 0.5 0.75 0.75 1 1 1 1OH 531 381 150 0.000% 0.000% 0.000%OK 5 5 0 0.000% 0.000% 0.000%OR 2,054 1,570 484 0.000% 0.000% 0.000%RI 471 316 155 0.212% 0.000% 0.645% 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2SC 2,998 2,625 373 0.000% 0.000% 0.000%SD 898 787 111 0.000% 0.000% 0.000%TN 79 13 66 0.000% 0.000% 0.000%TX 829 706 123 0.000% 0.000% 0.000%UT 7,103 5,915 1,188 0.000% 0.000% 0.000%VA 415 154 261 0.000% 0.000% 0.000%VT 1,287 1,097 190 0.311% 0.365% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5WI 3,161 3,069 92 0.000% 0.000% 0.000%WV 640 334 306 1.563% 1.796% 1.307% 0.5 0.53 0.5 0.83 0.53 1.13 20.565 1.13 40 40 1.13 40WY 1,250 939 311 0.000% 0.000% 0.000%Total 113,380 93,766 19,614 0.078% 0.075% 0.092% 0.18 0.18 0.5 1 1 2 5 5 40 531.1 5.01 531.1

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A49b. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 8 6 2 22,575 13,611 8,964 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 171 126 45 2,702,037 589,449 2,112,588 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 912 864 48 6,035,739 2,665,148 3,370,591 0.548% 0.463% 2.083% 17.050% 27.356% 8.901%CA 1,397 1,130 267 32,699,061 11,168,297 21,530,764 0.072% 0.000% 0.375% 0.001% 0.000% 0.001%CO 795 578 217 4,978,003 511,369 4,466,634 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 652 615 37 2,588,853 261,586 2,327,267 1.840% 1.951% 0.000% 0.113% 1.120% 0.000%DE 238 235 3 650,290 368,890 281,400 2.521% 2.553% 0.000% 1.032% 1.819% 0.000%FL 1,310 1,289 21 16,786,098 14,546,922 2,239,176 0.687% 0.698% 0.000% 18.380% 21.209% 0.000%GA 296 283 13 994,603 305,252 689,351 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 110 98 12 1,300,849 1,246,221 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 5 4 1 162,247 27,630 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 492 466 26 857,411 639,629 217,782 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,153 1,052 101 9,103,561 2,907,639 6,195,922 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 2.881% 0.000% 4.667% 8.155% 0.000% 8.878%MA 644 527 117 8,509,572 1,707,190 6,802,382 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MD 856 790 66 4,901,793 906,003 3,995,790 1.402% 1.266% 3.030% 35.270% 0.627% 43.125%ME 208 185 23 471,954 108,050 363,904 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,931 2,870 61 7,228,834 2,048,978 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,282 1,253 29 3,931,466 2,681,825 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,461 1,385 76 2,643,059 1,698,598 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 812 752 60 753,305 360,636 392,669 0.123% 0.133% 0.000% 0.010% 0.021% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.042% 0.045% 0.000% 0.001% 0.004% 0.000%ND 28 22 6 47,665 40,636 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 712 701 11 1,453,178 676,698 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 128 118 10 1,906,326 343,608 1,562,718 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 696 660 36 1,663,162 1,400,264 262,898 0.287% 0.303% 0.000% 0.835% 0.992% 0.000%NV 291 270 21 960,557 270,666 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,343 1,113 230 4,921,839 980,149 3,941,690 0.149% 0.180% 0.000% 0.012% 0.058% 0.000%OH 269 190 79 6,465,862 483,522 5,982,340 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OK 3 3 0 905 905 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OR 1,082 932 150 2,935,110 570,360 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 72 63 9 894,778 154,800 739,978 1.389% 0.000% 11.111% 2.978% 0.000% 3.601%SC 778 719 59 3,428,914 802,131 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 259 238 21 621,074 261,903 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 26 7 19 1,255,969 157,598 1,098,371 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 669 606 63 2,803,106 435,220 2,367,886 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,671 1,667,485 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 174 65 109 2,312,591 26,001 2,286,590 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 438 404 34 432,235 180,711 251,524 0.913% 0.990% 0.000% 0.148% 0.354% 0.000%WI 1,405 1,385 20 3,883,163 2,191,419 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 339 194 145 1,360,534 203,368 1,157,166 2.360% 3.093% 1.379% 0.642% 0.575% 0.653%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 30,876 28,100 2,776 167,378,431 61,701,854 105,676,577 0.230% 0.203% 0.504% 3.752% 6.233% 2.303%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A49c. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 0 1 0.072% 0.000% 0.375% 200 0 200 0.001% 0.000% 0.001%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 0 1 0.003% 0.000% 0.036% 200 0 200 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 200 μg/L

State

Number of Systems 

with At Least One Detection 

> 200 μg/L

Percent of Systems 

with At Least One Detection 

> 200 μg/L

Population Served by Systems 

with At Least One Detection 

> 200 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A49d. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 0 1 0.072% 0.000% 0.375% 200 0 200 0.001% 0.000% 0.001%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 0 1 0.003% 0.000% 0.036% 200 0 200 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A49e. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 0 1 0.072% 0.000% 0.375% 200 0 200 0.001% 0.000% 0.001%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 0 1 0.295% 0.000% 0.690% 3,186 0 3,186 0.234% 0.000% 0.275%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 21 17 4 0.066% 0.059% 0.142% 299,704 41,356 258,348 0.179% 0.067% 0.244%

Percent of Population Served 

with At Least One Detection 

> 2 μg/L

State

Number of Systems 

with At Least One Detection 

> 2 μg/L

Percent of Systems 

with At Least One Detection 

> 2 μg/L

Population Served by Systems 

with At Least One Detection 

> 2 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A50. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 1 μg/L 31,142 7 0.022% 68,667,605 11,376 0.017%

	
 31,142 21 0.067% 68,667,605 434,892 0.633%

> 1 μg/L 3,197 1 0.031% 121,840,104 429 0.000%

	
 3,197 8 0.250% 121,840,104 310,346 0.255%

> 1 μg/L 34,339 8 0.023% 190,507,709 11,805 0.006%

	
 34,339 29 0.084% 190,507,709 745,238 0.391%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A50a. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 113 48 65 0.000% 0.000% 0.000%AL 596 405 191 0.671% 0.494% 1.047% 0.07 0.19 0.07 0.145 0.4 0.085 0.61 0.61 0.1 0.61 0.61 0.1AR 1,588 1,357 231 0.000% 0.000% 0.000%AZ 6,850 5,427 1,423 0.409% 0.479% 0.141% 0.04 0.04 0.04 0.05 0.05 0.325 0.28 0.16 0.61 0.61 0.34 0.61CA 14,641 8,627 6,014 0.096% 0.104% 0.083% 0.05 0.05 0.18 0.325 0.2 0.4 0.7 10 0.51 10 10 0.51CO 2,526 1,847 679 0.079% 0.108% 0.000% 0.1 0.1 0.195 0.195 0.29 0.29 0.29 0.29CT 1,330 1,013 317 0.000% 0.000% 0.000%DE 826 788 38 0.000% 0.000% 0.000%FL 2,395 2,327 68 0.626% 0.602% 1.471% 0.01 0.01 0.14 0.01 0.01 0.14 0.32 0.32 0.14 0.32 0.32 0.14GA 1,481 1,402 79 0.068% 0.071% 0.000% 0.26 0.26 0.26 0.26 0.26 0.26 0.26 0.26HIIA 1,733 1,603 130 0.115% 0.125% 0.000% 0.2 0.2 0.3 0.3 0.4 0.4 0.4 0.4ID 2,096 1,814 282 0.191% 0.221% 0.000% 0.06 0.06 0.145 0.145 0.66 0.66 0.66 0.66IL 4,017 3,475 542 0.100% 0.086% 0.185% 0.09 0.09 0.32 0.135 0.11 0.32 0.32 0.16 0.32 0.32 0.16 0.32IN 2,286 2,119 167 0.131% 0.142% 0.000% 0.06 0.06 0.19 0.19 0.19 0.19 0.19 0.19KY 2,370 637 1,733 0.422% 0.157% 0.519% 0.01 4 0.01 0.5 4 0.5 2.5 4 1 4 4 1MA 2,953 2,167 786 0.034% 0.046% 0.000% 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04MD 2,515 1,699 816 3.459% 3.002% 4.412% 0.01 0.01 0.01 0.04 0.03 0.045 0.14 0.14 0.14 0.85 0.85 0.45ME 378 317 61 0.265% 0.315% 0.000% 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3MI 6,583 6,290 293 0.091% 0.095% 0.000% 0.1 0.1 0.175 0.175 0.29 0.29 0.29 0.29MN 4,627 4,495 132 0.108% 0.089% 0.758% 0.5 0.5 0.8 0.7 0.65 0.8 0.8 0.8 0.8 0.8 0.8 0.8MO 5,945 4,997 948 0.017% 0.020% 0.000% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01MT 3,280 2,970 310 0.122% 0.135% 0.000% 0.14 0.14 0.445 0.445 1 1 1 1NC 13,940 12,710 1,230 0.344% 0.330% 0.488% 0.04 0.04 0.07 0.105 0.095 0.12 0.4 0.4 0.13 3.6 3.6 0.13ND 398 338 60 1.759% 0.592% 8.333% 0.04 0.04 0.07 0.08 0.045 0.11 0.16 0.05 0.16 0.16 0.05 0.16NE 2,220 2,143 77 0.045% 0.047% 0.000% 0.67 0.67 0.67 0.67 0.67 0.67 0.67 0.67NH 4,193 3,874 319 0.048% 0.052% 0.000% 0.05 0.05 0.075 0.075 0.1 0.1 0.1 0.1NJ 199 174 25 0.000% 0.000% 0.000%NM 4,904 4,637 267 0.224% 0.237% 0.000% 0.01 0.01 0.25 0.25 0.97 0.97 1.3 1.3NV 1,635 1,188 447 0.550% 0.673% 0.224% 0.04 0.04 0.09 0.06 0.055 0.09 0.15 0.15 0.09 0.15 0.15 0.09NY 2,884 2,173 711 0.139% 0.184% 0.000% 0.84 0.84 1 1 5 5 5 5OH 599 404 195 0.334% 0.495% 0.000% 0.13 0.13 0.435 0.435 0.74 0.74 0.74 0.74OKOR 2,055 1,573 482 0.292% 0.318% 0.207% 0.04 0.05 0.04 0.095 0.1 0.04 0.3 0.3 0.04 0.3 0.3 0.04RI 881 619 262 0.000% 0.000% 0.000%SC 3,304 2,893 411 0.454% 0.449% 0.487% 0.02 0.02 0.03 0.06 0.08 0.04 0.19 0.19 0.05 0.25 0.25 0.05SD 952 842 110 0.000% 0.000% 0.000%TN 61 12 49 0.000% 0.000% 0.000%TX 13,213 6,622 6,591 0.015% 0.000% 0.030% 4 4 4 4 4 4 4 4UT 7,089 5,906 1,183 0.042% 0.051% 0.000% 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2VA 441 148 293 0.000% 0.000% 0.000%VT 1,303 1,109 194 0.230% 0.180% 0.515% 0.04 0.04 0.1 0.1 0.07 0.1 0.1 0.1 0.1 0.1 0.1 0.1WI 3,176 3,084 92 0.535% 0.551% 0.000% 0.04 0.04 0.08 0.08 0.24 0.24 0.3 0.3WV 644 337 307 1.863% 2.671% 0.977% 0.01 0.01 0.01 0.01 0.01 0.01 0.5 0.65 0.5 0.65 0.65 0.5WY 1,255 941 314 0.398% 0.531% 0.000% 0.1 0.1 0.19 0.19 2 2 2 2Total 136,475 107,551 28,924 0.248% 0.243% 0.270% 0.01 0.01 0.01 0.08 0.08 0.09 0.6 0.6 0.51 10 10 4

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A50b. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 21 15 6 316,496 84,946 231,550 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 184 131 53 3,496,123 619,137 2,876,986 2.174% 1.527% 3.774% 1.177% 2.084% 0.982%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 913 865 48 6,038,526 2,667,935 3,370,591 2.081% 1.965% 4.167% 7.673% 5.214% 9.619%CA 1,612 1,283 329 33,848,671 12,044,555 21,804,116 0.744% 0.546% 1.520% 0.622% 0.838% 0.502%CO 813 594 219 4,993,297 526,388 4,466,909 0.246% 0.337% 0.000% 0.009% 0.084% 0.000%CT 654 617 37 2,588,507 261,240 2,327,267 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 254 251 3 624,615 343,215 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,318 1,296 22 16,796,064 14,554,059 2,242,005 0.759% 0.694% 4.545% 18.816% 17.898% 24.778%GA 297 283 14 997,274 305,252 692,022 0.337% 0.353% 0.000% 0.045% 0.146% 0.000%HIIA 1,054 1,021 33 2,542,611 1,433,985 1,108,626 0.190% 0.196% 0.000% 0.041% 0.072% 0.000%ID 871 814 57 1,064,886 808,690 256,196 0.459% 0.491% 0.000% 0.142% 0.187% 0.000%IL 1,368 1,264 104 9,183,247 2,982,850 6,200,397 0.292% 0.237% 0.962% 0.102% 0.081% 0.112%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.214% 0.221% 0.000% 0.016% 0.030% 0.000%KY 243 93 150 4,612,320 375,460 4,236,860 3.292% 1.075% 4.667% 7.692% 0.506% 8.329%MA 644 527 117 8,506,732 1,704,350 6,802,382 0.155% 0.190% 0.000% 0.188% 0.938% 0.000%MD 863 795 68 4,906,061 907,954 3,998,107 8.111% 6.038% 32.353% 80.605% 31.999% 91.643%ME 216 190 26 491,237 116,848 374,389 0.463% 0.526% 0.000% 0.073% 0.308% 0.000%MI 2,919 2,858 61 7,224,193 2,044,337 5,179,856 0.137% 0.140% 0.000% 0.950% 3.358% 0.000%MN 1,288 1,259 29 3,933,642 2,684,001 1,249,641 0.155% 0.079% 3.448% 0.127% 0.001% 0.397%MO 1,476 1,399 77 3,281,938 1,700,607 1,581,331 0.068% 0.071% 0.000% 0.092% 0.178% 0.000%MT 846 786 60 757,811 365,142 392,669 0.118% 0.127% 0.000% 0.037% 0.077% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 1.734% 1.661% 2.920% 3.965% 8.347% 2.491%ND 209 182 27 559,198 253,973 305,225 1.435% 1.099% 3.704% 2.866% 0.085% 5.180%NE 739 728 11 1,454,673 678,193 776,480 0.135% 0.137% 0.000% 1.765% 3.786% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.162% 0.167% 0.000% 2.156% 5.151% 0.000%NJ 131 120 11 1,971,594 344,374 1,627,220 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 694 659 35 1,657,042 1,395,944 261,098 0.720% 0.759% 0.000% 32.761% 38.888% 0.000%NV 286 265 21 959,703 269,812 689,891 1.049% 0.755% 4.762% 34.877% 0.130% 48.467%NY 1,345 1,115 230 4,923,782 982,092 3,941,690 0.149% 0.179% 0.000% 0.040% 0.202% 0.000%OH 275 196 79 6,526,958 495,763 6,031,195 0.727% 1.020% 0.000% 0.030% 0.391% 0.000%OKOR 1,087 937 150 2,937,439 572,689 2,364,750 0.552% 0.534% 0.667% 0.725% 3.575% 0.035%RI 107 98 9 903,992 164,014 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 785 725 60 3,448,394 820,701 2,627,693 0.764% 0.690% 1.667% 1.484% 1.292% 1.543%SD 260 239 21 622,152 262,981 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 12 6 6 651,369 145,112 506,257 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 2,006 1,669 337 21,524,625 5,761,125 15,763,500 0.050% 0.000% 0.297% 0.002% 0.000% 0.003%UT 426 389 37 2,500,671 1,667,485 833,186 0.235% 0.257% 0.000% 2.679% 4.018% 0.000%VA 173 63 110 2,380,983 26,904 2,354,079 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 440 407 33 432,434 181,270 251,164 0.682% 0.491% 3.030% 3.739% 0.280% 6.236%WI 1,406 1,386 20 3,883,613 2,191,869 1,691,744 0.853% 0.866% 0.000% 0.649% 1.150% 0.000%WV 342 197 145 1,367,674 206,326 1,161,348 2.924% 4.569% 0.690% 0.991% 4.448% 0.377%WY 304 256 48 446,177 129,229 316,948 1.316% 1.563% 0.000% 0.170% 0.587% 0.000%Total 34,339 31,142 3,197 190,507,709 68,667,605 121,840,104 0.731% 0.639% 1.627% 5.094% 5.996% 4.585%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A50c. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.062% 0.078% 0.000% 50 50 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 1 0 0.412% 1.075% 0.000% 1,898 1,898 0 0.041% 0.506% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 2 0 0.085% 0.090% 0.000% 924 924 0 0.013% 0.053% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 1 1 0 0.144% 0.152% 0.000% 8,114 8,114 0 0.490% 0.581% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.074% 0.090% 0.000% 300 300 0 0.006% 0.031% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 0 1 0.050% 0.000% 0.297% 429 0 429 0.002% 0.000% 0.003%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 1 1 0 0.329% 0.391% 0.000% 90 90 0 0.020% 0.070% 0.000%Total 8 7 1 0.023% 0.022% 0.031% 11,805 11,376 429 0.006% 0.017% 0.0004%

Percent of Population Served 

with At Least One Detection 

> 1 μg/L

State

Number of Systems 

with At Least One Detection 

> 1 μg/L

Percent of Systems 

with At Least One Detection 

> 1 μg/L

Population Served by Systems 

with At Least One Detection 

> 1 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A50d. Pentachlorophenol – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 1 0 0.543% 0.763% 0.000% 7,857 7,857 0 0.225% 1.269% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 1 0 1 0.110% 0.000% 2.083% 24,219 0 24,219 0.401% 0.000% 0.719%CA 4 3 1 0.248% 0.234% 0.304% 58,165 46,165 12,000 0.172% 0.383% 0.055%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 1 1 0 0.115% 0.123% 0.000% 800 800 0 0.075% 0.099% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 4 1 3 1.646% 1.075% 2.000% 266,262 1,898 264,364 5.773% 0.506% 6.240%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 1 0 0.116% 0.126% 0.000% 249,760 249,760 0 5.091% 27.508% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 2 1 1 0.155% 0.079% 3.448% 4,995 35 4,960 0.127% 0.001% 0.397%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 280 280 0 0.037% 0.077% 0.000%NC 2 2 0 0.085% 0.090% 0.000% 924 924 0 0.013% 0.053% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 1 1 0 0.135% 0.137% 0.000% 25,676 25,676 0 1.765% 3.786% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 3 3 0 0.432% 0.455% 0.000% 89,527 89,527 0 5.403% 6.413% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 2 2 0 0.149% 0.179% 0.000% 1,985 1,985 0 0.040% 0.202% 0.000%OH 1 1 0 0.364% 0.510% 0.000% 1,900 1,900 0 0.029% 0.383% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 0 1 0.050% 0.000% 0.297% 429 0 429 0.002% 0.000% 0.003%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.585% 0.508% 0.690% 11,894 7,520 4,374 0.870% 3.645% 0.377%WY 2 2 0 0.658% 0.781% 0.000% 565 565 0 0.127% 0.437% 0.000%Total 29 21 8 0.084% 0.067% 0.250% 745,238 434,892 310,346 0.391% 0.633% 0.255%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A51. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 500 μg/L 29,914 0 0.000% 66,798,378 0 0.000%

	
 29,914 0 0.000% 66,798,378 0 0.000%

> 500 μg/L 2,996 0 0.000% 119,588,052 0 0.000%

	
 2,996 0 0.000% 119,588,052 0 0.000%

> 500 μg/L 32,910 0 0.000% 186,386,430 0 0.000%

	
 32,910 0 0.000% 186,386,430 0 0.000%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A51a. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 73 39 34 0.000% 0.000% 0.000%AL 550 404 146 0.364% 0.248% 0.685% 80.4 111.9 80.4 96.15 111.9 80.4 111.9 111.9 80.4 111.9 111.9 80.4AR 1,588 1,357 231 0.000% 0.000% 0.000%AZ 6,831 5,406 1,425 0.117% 0.111% 0.140% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1CA 14,022 8,210 5,812 0.071% 0.061% 0.086% 0.01 0.1 0.01 0.65 2.1 0.2 12.5 13 3 13 13 3CO 2,528 1,852 676 0.514% 0.648% 0.148% 0.5 0.5 0.73 0.73 0.73 0.73 1.4 1.4 0.73 1.6 1.6 0.73CT 1,325 1,010 315 0.000% 0.000% 0.000%DE 826 788 38 0.121% 0.127% 0.000% 0.19 0.19 0.19 0.19 0.19 0.19 0.19 0.19FL 2,388 2,321 67 0.461% 0.474% 0.000% 0.01 0.01 0.01 0.01 0.09 0.09 0.1 0.1GA 1,431 1,353 78 0.000% 0.000% 0.000%HIIA 1,737 1,607 130 0.345% 0.373% 0.000% 1.6 1.6 5.8 5.8 11 11 11 11ID 2,057 1,777 280 0.000% 0.000% 0.000%IL 3,241 2,688 553 0.000% 0.000% 0.000%IN 2,258 2,093 165 0.221% 0.191% 0.606% 0.1 0.1 0.4 0.2 0.2 0.4 3.4 3.4 0.4 3.4 3.4 0.4KY 1,746 443 1,303 0.515% 0.226% 0.614% 0.05 190 0.05 0.5 190 0.3 190 190 100 190 190 100MA 2,967 2,176 791 0.135% 0.184% 0.000% 0.1 0.1 0.685 0.685 1.2 1.2 1.2 1.2MD 2,488 1,699 789 1.166% 0.942% 1.648% 0.05 0.1 0.05 0.2 0.19 0.2 3.01 2.48 3.46 3.76 2.67 3.76ME 378 317 61 0.000% 0.000% 0.000%MI 6,395 6,103 292 0.047% 0.049% 0.000% 2 2 2 2 2 2 2 2MN 4,627 4,495 132 0.000% 0.000% 0.000%MO 5,803 4,984 819 0.000% 0.000% 0.000%MT 3,187 2,905 282 0.157% 0.172% 0.000% 0.14 0.14 1.4 1.4 2 2 2 2NC 13,934 12,704 1,230 0.201% 0.197% 0.244% 0.1 0.1 0.2 0.205 0.19 0.26 0.65 0.65 0.28 1.9 1.9 0.28ND 411 348 63 4.136% 4.598% 1.587% 0.1 0.1 0.11 0.3 0.31 0.11 2.3 2.3 0.11 2.47 2.47 0.11NE 2,220 2,143 77 0.180% 0.187% 0.000% 1.6 1.6 3.2 3.2 3.4 3.4 3.4 3.4NH 4,193 3,874 319 0.024% 0.026% 0.000% 2 2 2 2 2 2 2 2NJ 162 144 18 0.000% 0.000% 0.000%NM 4,347 4,100 247 0.023% 0.024% 0.000% 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4NV 1,569 1,161 408 0.064% 0.086% 0.000% 0.11 0.11 0.11 0.11 0.11 0.11 0.11 0.11NY 2,877 2,165 712 0.070% 0.092% 0.000% 1 1 1.05 1.05 1.1 1.1 1.1 1.1OH 587 392 195 0.170% 0.000% 0.513% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2OKOR 2,067 1,583 484 0.145% 0.190% 0.000% 0.2 0.2 0.5 0.5 0.5 0.5 0.5 0.5RI 740 498 242 0.270% 0.201% 0.413% 0.1 0.1 0.11 0.105 0.1 0.11 0.11 0.1 0.11 0.11 0.1 0.11SC 3,303 2,893 410 0.303% 0.346% 0.000% 0.05 0.05 0.195 0.195 0.92 0.92 1.3 1.3SD 965 856 109 0.311% 0.350% 0.000% 1.96 1.96 2.04 2.04 3.42 3.42 3.42 3.42TN 58 12 46 0.000% 0.000% 0.000%TX 2,174 1,343 831 0.000% 0.000% 0.000%UT 7,079 5,897 1,182 0.000% 0.000% 0.000%VA 441 148 293 0.000% 0.000% 0.000%VT 1,298 1,104 194 0.154% 0.181% 0.000% 0.04 0.04 0.395 0.395 0.75 0.75 0.75 0.75WI 3,161 3,069 92 0.158% 0.163% 0.000% 0.1 0.1 0.1 0.1 1.1 1.1 1.1 1.1WV 646 338 308 1.858% 2.663% 0.974% 0.02 0.02 0.02 0.025 0.03 0.02 0.1 0.1 0.5 0.5 0.1 0.5WY 1,242 935 307 0.081% 0.107% 0.000% 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5Total 121,920 99,734 22,186 0.163% 0.159% 0.180% 0.01 0.01 0.01 0.24 0.25 0.2 3 2.48 3.235 190 190 100

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A51b. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 19 14 5 316,371 84,921 231,450 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 176 128 48 2,771,799 604,527 2,167,272 1.136% 0.781% 2.083% 0.252% 0.289% 0.242%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 918 870 48 6,045,047 2,674,456 3,370,591 0.436% 0.345% 2.083% 7.129% 4.897% 8.901%CA 1,582 1,261 321 33,364,134 12,015,440 21,348,694 0.379% 0.238% 0.935% 0.434% 0.191% 0.570%CO 813 594 219 4,993,297 526,388 4,466,909 0.861% 1.010% 0.457% 0.159% 0.939% 0.067%CT 656 619 37 2,589,596 262,329 2,327,267 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 254 251 3 624,615 343,215 281,400 0.394% 0.398% 0.000% 0.005% 0.009% 0.000%FL 1,318 1,296 22 16,796,064 14,554,059 2,242,005 0.379% 0.386% 0.000% 15.504% 17.893% 0.000%GA 297 283 14 997,274 305,252 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 1,055 1,022 33 2,542,641 1,434,015 1,108,626 0.095% 0.098% 0.000% 0.017% 0.031% 0.000%ID 870 813 57 1,064,826 808,630 256,196 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,157 1,056 101 9,106,231 2,910,309 6,195,922 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,403 1,359 44 4,870,706 2,550,970 2,319,736 0.356% 0.294% 2.273% 5.417% 0.013% 11.360%KY 242 92 150 4,606,159 369,299 4,236,860 2.893% 1.087% 4.000% 7.899% 0.291% 8.562%MA 645 528 117 8,509,903 1,707,521 6,802,382 0.620% 0.758% 0.000% 0.516% 2.572% 0.000%MD 863 795 68 4,906,061 907,954 3,998,107 2.897% 1.761% 16.176% 74.535% 2.953% 90.791%ME 216 190 26 491,237 116,848 374,389 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,908 2,847 61 7,222,532 2,042,676 5,179,856 0.069% 0.070% 0.000% 0.015% 0.054% 0.000%MN 1,288 1,259 29 3,933,642 2,684,001 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,475 1,398 77 3,281,888 1,700,557 1,581,331 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 846 786 60 757,811 365,142 392,669 0.355% 0.382% 0.000% 0.286% 0.594% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.803% 0.718% 2.190% 12.034% 4.419% 14.597%ND 209 182 27 559,198 253,973 305,225 2.871% 2.747% 3.704% 1.964% 2.829% 1.245%NE 739 728 11 1,454,673 678,193 776,480 0.541% 0.549% 0.000% 0.495% 1.061% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.081% 0.084% 0.000% 0.008% 0.020% 0.000%NJ 127 116 11 1,969,193 341,973 1,627,220 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 692 657 35 1,656,892 1,395,794 261,098 0.145% 0.152% 0.000% 0.490% 0.581% 0.000%NV 287 266 21 960,268 270,377 689,891 0.348% 0.376% 0.000% 0.052% 0.185% 0.000%NY 1,346 1,116 230 4,923,979 982,289 3,941,690 0.074% 0.090% 0.000% 0.034% 0.172% 0.000%OH 273 194 79 6,517,900 486,705 6,031,195 0.366% 0.000% 1.266% 0.874% 0.000% 0.944%OKOR 1,089 939 150 2,939,339 574,589 2,364,750 0.184% 0.213% 0.000% 0.171% 0.875% 0.000%RI 89 80 9 900,695 160,717 739,978 2.247% 1.250% 11.111% 3.131% 0.964% 3.601%SC 785 725 60 3,448,394 820,701 2,627,693 0.764% 0.828% 0.000% 0.111% 0.468% 0.000%SD 260 239 21 622,152 262,981 359,171 1.154% 1.255% 0.000% 2.386% 5.645% 0.000%TN 10 5 5 645,820 144,963 500,857 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 856 702 154 18,700,247 4,013,688 14,686,559 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,671 1,667,485 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 173 63 110 2,380,983 26,904 2,354,079 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 440 407 33 432,449 181,285 251,164 0.455% 0.491% 0.000% 0.117% 0.280% 0.000%WI 1,406 1,386 20 3,883,613 2,191,869 1,691,744 0.284% 0.289% 0.000% 0.680% 1.204% 0.000%WV 342 197 145 1,367,674 206,326 1,161,348 2.924% 4.569% 0.690% 0.465% 0.961% 0.377%WY 304 256 48 446,177 129,229 316,948 0.329% 0.391% 0.000% 0.157% 0.542% 0.000%Total 32,910 29,914 2,996 186,386,430 66,798,378 119,588,052 0.413% 0.351% 1.035% 4.575% 4.486% 4.624%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A51c. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 500 μg/L

State

Number of Systems 

with At Least One Detection 

> 500 μg/L

Percent of Systems 

with At Least One Detection 

> 500 μg/L

Population Served by Systems 

with At Least One Detection 

> 500 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A51d. Picloram – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.5 μg/L 16,249 2 0.012% 45,009,798 125,046 0.278%

	
 16,249 4 0.025% 45,009,798 128,040 0.284%

> 0.5 μg/L 2,144 0 0.000% 79,104,410 0 0.000%

	
 2,144 3 0.140% 79,104,410 593,206 0.750%

> 0.5 μg/L 18,393 2 0.011% 124,114,208 125,046 0.101%

	
 18,393 7 0.038% 124,114,208 721,246 0.581%

Ground Water

Surface Water

Combined Ground & 

Surface Water

Table A52. Polychlorinated biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

Table A52a. Polychlorinated biphenyls (PCBs) AK 70 50 20 0.000% 0.000% 0.000%AL 537 386 151 0.745% 0.259% 1.987% 0.12 0.33 0.12 0.17 0.33 0.16 0.33 0.33 0.18 0.33 0.33 0.18AR 1,641 1,395 246 0.000% 0.000% 0.000%AZ 1,326 1,100 226 0.603% 0.727% 0.000% 0.1 0.1 0.17 0.17 0.24 0.24 0.24 0.24CA 10,122 5,952 4,170 0.010% 0.017% 0.000% 0.52 0.52 0.52 0.52 0.52 0.52 0.52 0.52CO 2,524 1,819 705 0.000% 0.000% 0.000%CT 1,275 956 319 0.000% 0.000% 0.000%DE 31 31 0 0.000% 0.000% 0.000%FL 2,377 2,312 65 0.421% 0.433% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1GA 1,423 1,344 79 0.000% 0.000% 0.000%HIIA 9 8 1 0.000% 0.000% 0.000%ID 1,307 1,081 226 0.000% 0.000% 0.000%IL 4,447 3,726 721 0.000% 0.000% 0.000%IN 960 818 142 0.000% 0.000% 0.000%KY 1,686 426 1,260 0.237% 0.000% 0.317% 0.05 0.05 0.5 0.5 0.5 0.5 0.5 0.5MAMD 206 43 163 0.971% 2.326% 0.613% 0.12 0.21 0.12 0.165 0.21 0.12 0.21 0.21 0.12 0.21 0.21 0.12ME 163 142 21 0.000% 0.000% 0.000%MIMNMOMT 1,767 1,603 164 0.000% 0.000% 0.000%NC 13,170 12,078 1,092 0.008% 0.008% 0.000% 0.31 0.31 0.31 0.31 0.31 0.31 0.31 0.31ND 49 27 22 0.000% 0.000% 0.000%NENHNJNM 859 805 54 0.000% 0.000% 0.000%NV 945 750 195 0.106% 0.000% 0.513% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5NY 2,854 2,107 747 0.000% 0.000% 0.000%OH 432 327 105 1.620% 2.141% 0.000% 0.1 0.1 0.6 0.6 1.44 1.44 1.44 1.44OKOR 2,047 1,566 481 0.000% 0.000% 0.000%RISCSD 953 844 109 0.000% 0.000% 0.000%TN 61 11 50 0.000% 0.000% 0.000%TX 770 753 17 0.000% 0.000% 0.000%UT 7,092 5,914 1,178 0.000% 0.000% 0.000%VA 479 173 306 0.000% 0.000% 0.000%VT 1,015 875 140 0.099% 0.114% 0.000% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2WI 2,830 2,737 93 0.000% 0.000% 0.000%WV 527 262 265 2.087% 3.053% 1.132% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.5 0.5 0.1 0.5WY 1,262 944 318 0.000% 0.000% 0.000%Total 67,216 53,365 13,851 0.074% 0.071% 0.087% 0.05 0.1 0.05 0.1 0.1 0.17 0.54 0.6 0.5 1.44 1.44 0.5

– Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 14 9 5 23,947 14,048 9,899 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 174 128 46 2,733,250 611,586 2,121,664 1.724% 0.781% 4.348% 9.200% 0.480% 11.714%AR 437 366 71 2,445,874 904,110 1,541,764 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 366 337 29 4,849,157 1,888,824 2,960,333 0.546% 0.593% 0.000% 0.961% 2.466% 0.000%CA 1,332 1,079 253 29,239,114 9,516,308 19,722,806 0.075% 0.093% 0.000% 0.428% 1.314% 0.000%CO 810 591 219 4,991,979 525,070 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 643 605 38 2,589,577 255,690 2,333,887 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 24 24 0 94,720 94,720 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,310 1,289 21 16,785,272 14,546,096 2,239,176 0.382% 0.388% 0.000% 15.514% 17.903% 0.000%GA 291 277 14 967,784 275,762 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 2 1 1 162,118 27,501 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 544 515 29 875,826 656,625 219,201 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,358 1,254 104 9,182,612 2,982,215 6,200,397 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 581 537 44 3,757,238 1,437,502 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 242 93 149 4,602,489 375,460 4,227,029 0.826% 0.000% 1.342% 6.721% 0.000% 7.318%MAMD 55 28 27 3,859,880 86,871 3,773,009 3.636% 3.571% 3.704% 0.029% 0.035% 0.029%ME 130 118 12 284,816 85,281 199,535 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MIMNMOMT 705 650 55 726,404 336,830 389,574 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.042% 0.045% 0.000% 0.001% 0.003% 0.000%ND 13 7 6 25,452 18,423 7,029 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NENHNJNM 271 258 13 1,365,772 1,209,925 155,847 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 249 229 20 946,071 256,272 689,799 0.402% 0.000% 5.000% 35.343% 0.000% 48.474%NY 1,246 1,030 216 4,789,355 933,413 3,855,942 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 245 176 69 6,367,123 462,749 5,904,374 0.816% 1.136% 0.000% 0.007% 0.097% 0.000%OKOR 1,083 933 150 2,936,604 571,854 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RISCSD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 11 5 6 648,070 127,613 520,457 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 617 609 8 508,429 469,714 38,715 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 427 390 37 2,500,736 1,667,550 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 178 70 108 2,303,114 29,317 2,273,797 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 410 379 31 426,022 181,998 244,024 0.244% 0.264% 0.000% 0.072% 0.169% 0.000%WI 1,384 1,364 20 3,841,377 2,149,633 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 311 174 137 1,330,400 184,957 1,145,443 2.894% 4.598% 0.730% 0.453% 0.896% 0.382%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 18,393 16,249 2,144 124,114,208 45,009,798 79,104,410 0.158% 0.135% 0.326% 2.964% 6.179% 1.135%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting

Table A52b. Polychlorinated biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A52c. Polychlorinated biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.075% 0.093% 0.000% 125,000 125,000 0 0.428% 1.314% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MAMD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MIMNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NENHNJNM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 1 1 0 0.408% 0.568% 0.000% 46 46 0 0.001% 0.010% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RISCSD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 2 0 0.011% 0.012% 0.000% 125,046 125,046 0 0.101% 0.278% 0.000%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 1 0 0.575% 0.781% 0.000% 2,937 2,937 0 0.107% 0.480% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.075% 0.093% 0.000% 125,000 125,000 0 0.428% 1.314% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 254,462 0 254,462 5.529% 0.000% 6.020%MAMD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MIMNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 57 57 0 0.001% 0.003% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NENHNJNM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 0 1 0.402% 0.000% 5.000% 334,370 0 334,370 35.343% 0.000% 48.474%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 1 1 0 0.408% 0.568% 0.000% 46 46 0 0.001% 0.010% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RISCSD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 1 0 1 0.322% 0.000% 0.730% 4,374 0 4,374 0.329% 0.000% 0.382%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 7 4 3 0.038% 0.025% 0.140% 721,246 128,040 593,206 0.581% 0.284% 0.750%

Percent of Population Served 

with At Least One Detection 

	
 State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	


 Table A52d. Polychlorinated biphenyls (PCBs) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53 (Original Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems 

Exceeding 

Threshold of 

Interest

% Systems 

Exceeding 

Threshold of 

Interest

Total Pop. Served 

by Systems 

Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of 

Interest

> 5 pCi/L 6,190 488 7.884% 15,006,355 2,143,386 14.283%


	
 6,190 1,185 19.144% 15,006,355 4,652,946 31.007%

> 5 pCi/L 694 14 2.017% 32,416,085 2,418,615 7.461%


	
 694 37 5.331% 32,416,085 4,510,400 13.914%

> 5 pCi/L 6,884 502 7.292% 47,422,440 4,562,001 9.620%


	
 6,884 1,222 17.751% 47,422,440 9,163,346 19.323%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53a (Original Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 5 5 0 60.000% 60.000% 0.08 0.08 0.09 0.09 0.13 0.13 0.13 0.13AL 29 25 4 82.759% 92.000% 25.000% 0.1 0.6 0.1 2.33 2.37 0.1 5.6 5.6 0.1 17.9 17.9 0.1ARAZ 1,721 1,092 629 27.077% 31.410% 19.555% 0.2 0.2 0.2 0.5 0.5 0.5 3.5 4.5 1.8 12.8 12.8 5.45CA 1,838 1,149 689 55.658% 59.443% 49.347% 0.03 0.03 0.07 0.85 0.89 0.785 1.77 1.97 1.4 142 21.71 142CO 366 342 24 85.519% 86.550% 70.833% 0.03 0.03 0.2 6.1 6.6 1 19.2 19.9 1.7 47 47 3.2CT 247 216 31 75.709% 78.704% 54.839% 0.01 0.01 0.2 1.6 1.765 1.1 14.3 14.425 2.4 39.92 39.92 2.76DEFLGA 4 0 4 100.000% 100.000% 5.7 5.7 5.7 5.7 5.7 5.7 5.7 5.7HIIA 1,539 1,492 47 68.421% 69.839% 23.404% 0.2 0.2 0.6 2.3 2.3 1 6.7 6.7 2.2 19.2 19.2 3.4ID 897 804 93 32.776% 33.582% 25.806% 0.1 0.1 0.1 0.4 0.4 0.45 3.2 3.2 3.76 19 19 4.7IL 3,187 3,147 40 98.463% 98.538% 92.500% 0.1 0.1 0.2 4.8 4.9 1 12.9 13 1.9 28.2 28.2 2.6IN 3 3 0 100.000% 100.000% 4.1 4.1 5.6 5.6 6.2 6.2 6.2 6.2KY 3 1 2 100.000% 100.000% 100.000% 0.2 0.2 0.3 0.3 0.2 1.25 2.2 0.2 2.2 2.2 0.2 2.2MAMD 674 606 68 32.938% 34.158% 22.059% 0.2 0.2 0.26 2.2 2.3 1.253 5.5 5.7 2.42 14.3 14.3 5.083ME 98 91 7 94.898% 94.505% 100.000% 0.05 0.05 0.2 0.56 0.525 2.42 3.48 3.44 7.93 8.06 8.06 7.93MIMNMO 24 24 0 95.833% 95.833% 0.3 0.3 4.2 4.2 9.2 9.2 16.1 16.1MT 912 819 93 30.044% 31.258% 19.355% 0.2 0.2 0.2 0.8 0.75 1.8 4.5 4.4 6 11 11 6.1NC 383 343 40 65.274% 72.303% 5.000% 0.06 0.06 0.17 3.3 3.3 0.735 10.8 10.9 1.3 45.9 45.9 1.3ND 181 164 17 32.044% 33.537% 17.647% 0.3 0.3 1.09 1.55 1.56 1.17 2.79 2.79 1.4 6.26 6.26 1.4NE 521 511 10 76.200% 76.321% 70.000% 0.1 0.1 0.5 1 1 0.9 3 3 3.1 7.6 7.6 3.1NHNJ 58 45 13 79.310% 100.000% 7.692% 0.08 0.08 2.98 3.395 3.59 2.98 5.35 5.35 2.98 8.26 8.26 2.98NM 62 62 0 51.613% 51.613% 2.28 2.28 4.675 4.675 8.76 8.76 10.57 10.57NV 99 76 23 47.475% 50.000% 39.130% 0.2 0.2 0.2 0.688 0.939 0.22 3.416 3.416 4.06 6.93 6.93 4.06NY 263 198 65 84.411% 88.384% 72.308% 0.0495 0.079 0.0495 1.78 2.4 0.8 7.6 8.1 3.7 28.7 28.7 9.41OH 31 26 5 38.710% 42.308% 20.000% 1.01 1.01 1.38 1.845 2 1.38 6.35 6.35 1.38 8.23 8.23 1.38OKOR 954 753 201 20.440% 17.397% 31.841% 0.0293 0.2 0.0293 1.4 1.43 1.335 2.45 2.87 2.2 4.9 4.9 3RI 184 167 17 83.152% 85.030% 64.706% 0.06 0.06 0.23 1.13 1.13 0.51 3.35 3.38 1.39 13.42 13.42 1.76SC 1,059 992 67 39.377% 40.423% 23.881% 1 1 1 2.7 2.7 1.3 9 9 4.3 25 25 5.1SD 5 4 1 40.000% 50.000% 0.000% 1.3 1.3 1.55 1.55 1.8 1.8 1.8 1.8TNTX 1,192 1,144 48 86.242% 86.976% 68.750% 0.2 0.2 0.2 0.9 0.99 0.3 3.8 3.8 1.1 22.6 22.6 8.3UT 115 35 80 50.435% 71.429% 41.250% 1 1 1 2 3 2 7 9 2 10 10 2VA 10 9 1 100.000% 100.000% 100.000% 0.1 0.873 0.1 5.195 5.64 0.1 8.625 9.62 0.1 9.62 9.62 0.1VT 429 391 38 80.420% 81.074% 73.684% 0.04 0.04 0.06 0.45 0.54 0.2 3.7 4.15 0.98 19.43 19.43 1.7WI 1,026 982 44 99.708% 99.695% 100.000% 0.02 0.03 0.02 3.6 3.54 5.3 7.9 7.8 9 26.7 26.7 10.4WV 250 134 116 92.800% 95.522% 89.655% 0.1 0.1 0.1 0.5 0.6 0.3 2.5 4.5 0.9 7.9 7.9 2.6WY 83 68 15 68.675% 72.059% 53.333% 0.1 0.1 0.2 2.8 3.4 0.65 6.7 6.7 9.8 9.8 8.2 9.8Total 18,452 15,920 2,532 63.446% 67.079% 40.600% 0.01 0.01 0.02 1.9 2.1 0.785 9 9.3 2.4 142 47 142

Median Detect 

Concentration (pCi/L)

Maximum Detect 

Concentration (pCi/L)

90th Percentile Detect 

Concentration (pCi/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (pCi/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53b (Original Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 5 5 0 14,544 14,544 0 60.000% 60.000% 36.806% 36.806%AL 11 10 1 775,613 114,179 661,434 90.909% 90.000% 100.000% 99.936% 99.564% 100.000%ARAZ 269 258 11 4,744,269 1,581,000 3,163,269 45.725% 44.186% 81.818% 91.570% 77.059% 98.823%CA 212 156 56 10,706,892 1,812,964 8,893,928 60.849% 59.615% 64.286% 69.521% 71.088% 69.202%CO 124 107 17 439,620 128,156 311,464 75.000% 74.766% 76.471% 61.658% 85.794% 51.727%CT 107 96 11 1,067,986 65,967 1,002,019 77.570% 79.167% 63.636% 93.516% 93.995% 93.485%DEFLGA 1 0 1 715,820 0 715,820 100.000% 100.000% 100.000% 100.000%HIIA 872 839 33 2,478,368 1,369,742 1,108,626 63.647% 65.316% 21.212% 54.105% 60.605% 46.075%ID 421 399 22 851,551 636,614 214,937 42.755% 43.108% 36.364% 84.409% 82.341% 90.535%IL 349 329 20 1,942,114 1,325,106 617,008 98.281% 98.480% 95.000% 99.201% 99.506% 98.545%IN 2 2 0 928 928 0 100.000% 100.000% 100.000% 100.000%KY 2 1 1 151,039 84,935 66,104 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%MAMD 314 283 31 2,768,089 757,553 2,010,536 19.427% 18.728% 25.806% 22.196% 63.832% 6.507%ME 59 56 3 45,990 43,281 2,709 96.610% 96.429% 100.000% 99.446% 99.411% 100.000%MIMNMO 22 22 0 31,449 31,449 0 95.455% 95.455% 96.642% 96.642%MT 551 496 55 690,718 299,264 391,454 37.387% 39.113% 21.818% 25.363% 52.347% 4.733%NC 159 130 29 1,589,233 220,164 1,369,069 55.975% 66.923% 6.897% 31.520% 65.815% 26.004%ND 173 156 17 545,827 248,887 296,940 33.526% 35.256% 17.647% 24.155% 25.468% 23.055%NE 223 216 7 813,616 274,704 538,912 79.372% 79.630% 71.429% 95.944% 89.687% 99.133%NHNJ 27 25 2 675,668 320,792 354,876 96.296% 100.000% 50.000% 53.842% 100.000% 12.117%NM 20 20 0 13,812 13,812 0 40.000% 40.000% 53.562% 53.562%NV 34 29 5 645,637 56,442 589,195 58.824% 55.172% 80.000% 96.121% 70.329% 98.591%NY 116 84 32 2,207,311 169,118 2,038,193 82.759% 88.095% 68.750% 85.654% 76.391% 86.423%OH 19 17 2 358,320 142,727 215,593 47.368% 47.059% 50.000% 0.742% 1.810% 0.035%OKOR 613 486 127 2,577,462 419,886 2,157,576 24.633% 22.222% 33.858% 64.676% 30.766% 71.275%RI 53 48 5 758,560 141,563 616,997 90.566% 93.750% 60.000% 42.507% 99.691% 29.387%SC 379 353 26 1,732,025 499,578 1,232,447 45.646% 47.025% 26.923% 30.981% 69.863% 15.220%SD 4 3 1 2,200 500 1,700 25.000% 33.333% 0.000% 4.545% 20.000% 0.000%TNTX 875 841 34 3,938,407 2,409,649 1,528,758 89.371% 89.774% 79.412% 93.060% 95.109% 89.830%UT 15 14 1 452,327 300,067 152,260 93.333% 92.857% 100.000% 97.170% 95.734% 100.000%VA 4 3 1 1,208 198 1,010 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%VT 312 282 30 260,741 148,444 112,297 80.128% 80.851% 73.333% 85.101% 89.690% 79.035%WI 294 291 3 2,285,860 1,216,339 1,069,521 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%WV 208 105 103 1,012,959 110,743 902,216 93.269% 95.238% 91.262% 97.734% 98.287% 97.666%WY 35 28 7 126,277 47,060 79,217 51.429% 53.571% 42.857% 48.572% 90.278% 23.795%Total 6,884 6,190 694 47,422,440 15,006,355 32,416,085 62.188% 63.231% 52.882% 71.796% 79.462% 68.248%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53c (Original Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0 0 0 0.000% 0.000%AL 3 3 0 27.273% 30.000% 0.000% 39,261 39,261 0 5.062% 34.385% 0.000%ARAZ 7 6 1 2.602% 2.326% 9.091% 1,584,453 50,871 1,533,582 33.397% 3.218% 48.481%CA 6 5 1 2.830% 3.205% 1.786% 52,176 51,676 500 0.487% 2.850% 0.006%CO 30 30 0 24.194% 28.037% 0.000% 9,181 9,181 0 2.088% 7.164% 0.000%CT 11 11 0 10.280% 11.458% 0.000% 2,742 2,742 0 0.257% 4.157% 0.000%DEFLGA 1 0 1 100.000% 100.000% 715,820 0 715,820 100.000% 100.000%HIIA 37 37 0 4.243% 4.410% 0.000% 120,542 120,542 0 4.864% 8.800% 0.000%ID 7 7 0 1.663% 1.754% 0.000% 1,524 1,524 0 0.179% 0.239% 0.000%IL 133 133 0 38.109% 40.426% 0.000% 838,292 838,292 0 43.164% 63.262% 0.000%IN 2 2 0 100.000% 100.000% 928 928 0 100.000% 100.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MAMD 8 7 1 2.548% 2.473% 3.226% 262,912 257,812 5,100 9.498% 34.032% 0.254%ME 3 2 1 5.085% 3.571% 33.333% 751 148 603 1.633% 0.342% 22.259%MIMNMO 7 7 0 31.818% 31.818% 16,590 16,590 0 52.752% 52.752%MT 13 9 4 2.359% 1.815% 7.273% 13,822 6,960 6,862 2.001% 2.326% 1.753%NC 32 32 0 20.126% 24.615% 0.000% 14,142 14,142 0 0.890% 6.423% 0.000%ND 1 1 0 0.578% 0.641% 0.000% 91 91 0 0.017% 0.037% 0.000%NE 3 3 0 1.345% 1.389% 0.000% 1,599 1,599 0 0.197% 0.582% 0.000%NHNJ 4 4 0 14.815% 16.000% 0.000% 23,120 23,120 0 3.422% 7.207% 0.000%NM 4 4 0 20.000% 20.000% 3,267 3,267 0 23.653% 23.653%NV 1 1 0 2.941% 3.448% 0.000% 1,240 1,240 0 0.192% 2.197% 0.000%NY 19 18 1 16.379% 21.429% 3.125% 4,149 4,019 130 0.188% 2.376% 0.006%OH 1 1 0 5.263% 5.882% 0.000% 100 100 0 0.028% 0.070% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 4 4 0 7.547% 8.333% 0.000% 929 929 0 0.122% 0.656% 0.000%SC 32 31 1 8.443% 8.782% 3.846% 59,388 18,838 40,550 3.429% 3.771% 3.290%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TNTX 41 40 1 4.686% 4.756% 2.941% 97,283 91,683 5,600 2.470% 3.805% 0.366%UT 3 3 0 20.000% 21.429% 0.000% 116,495 116,495 0 25.755% 38.823% 0.000%VA 2 2 0 50.000% 66.667% 0.000% 154 154 0 12.748% 77.778% 0.000%VT 7 7 0 2.244% 2.482% 0.000% 1,504 1,504 0 0.577% 1.013% 0.000%WI 74 73 1 25.170% 25.086% 33.333% 571,748 468,730 103,018 25.012% 38.536% 9.632%WV 3 3 0 1.442% 2.857% 0.000% 422 422 0 0.042% 0.381% 0.000%WY 3 2 1 8.571% 7.143% 14.286% 7,376 526 6,850 5.841% 1.118% 8.647%

Total 502 488 14 7.292% 7.884% 2.017% 4,562,001 2,143,386 2,418,615 9.620% 14.283% 7.461%

Percent of Population Served 

with At Least One Detection 

> 5 pCi/L

State

Number of Systems 

with At Least One Detection 

> 5 pCi/L

Percent of Systems 

with At Least One Detection 

> 5 pCi/L

Population Served by Systems 

with At Least One Detection 

> 5 pCi/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53d (Original Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 4 4 0 36.364% 40.000% 0.000% 75,210 75,210 0 9.697% 65.870% 0.000%ARAZ 20 17 3 7.435% 6.589% 27.273% 2,241,484 82,677 2,158,807 47.246% 5.229% 68.246%CA 15 13 2 7.075% 8.333% 3.571% 430,071 193,571 236,500 4.017% 10.677% 2.659%CO 37 36 1 29.839% 33.645% 5.882% 36,974 24,774 12,200 8.410% 19.331% 3.917%CT 16 15 1 14.953% 15.625% 9.091% 15,957 3,726 12,231 1.494% 5.648% 1.221%DEFLGA 1 0 1 100.000% 0.000% 100.000% 715,820 0 715,820 100.000% 0.000% 100.000%HIIA 189 188 1 21.674% 22.408% 3.030% 483,481 398,453 85,028 19.508% 29.090% 7.670%ID 45 43 2 10.689% 10.777% 9.091% 293,644 107,504 186,140 34.483% 16.887% 86.602%IL 199 198 1 57.020% 60.182% 5.000% 1,046,785 1,044,949 1,836 53.899% 78.858% 0.298%IN 2 2 0 100.000% 100.000% 0.000% 928 928 0 100.000% 100.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MAMD 18 17 1 5.732% 6.007% 3.226% 346,267 341,167 5,100 12.509% 45.035% 0.254%ME 6 4 2 10.169% 7.143% 66.667% 2,037 371 1,666 4.429% 0.857% 61.499%MIMNMO 17 17 0 77.273% 77.273% 0.000% 21,258 21,258 0 67.595% 67.595% 0.000%MT 64 56 8 11.615% 11.290% 14.545% 112,051 98,173 13,878 16.222% 32.805% 3.545%NC 47 47 0 29.560% 36.154% 0.000% 108,462 108,462 0 6.825% 49.264% 0.000%ND 9 9 0 5.202% 5.769% 0.000% 8,353 8,353 0 1.530% 3.356% 0.000%NE 50 49 1 22.422% 22.685% 14.286% 629,360 117,196 512,164 77.353% 42.663% 95.037%NHNJ 14 13 1 51.852% 52.000% 50.000% 307,499 264,499 43,000 45.510% 82.452% 12.117%NM 8 8 0 40.000% 40.000% 0.000% 7,398 7,398 0 53.562% 53.562% 0.000%NV 3 2 1 8.824% 6.897% 20.000% 336,210 1,840 334,370 52.074% 3.260% 56.750%NY 30 28 2 25.862% 33.333% 6.250% 8,553 7,953 600 0.387% 4.703% 0.029%OH 3 3 0 15.789% 17.647% 0.000% 667 667 0 0.186% 0.467% 0.000%OKOR 15 12 3 2.447% 2.469% 2.362% 58,535 30,518 28,017 2.271% 7.268% 1.299%RI 13 13 0 24.528% 27.083% 0.000% 23,286 23,286 0 3.070% 16.449% 0.000%SC 70 69 1 18.470% 19.547% 3.846% 157,706 117,156 40,550 9.105% 23.451% 3.290%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TNTX 118 117 1 13.486% 13.912% 2.941% 297,167 291,567 5,600 7.545% 12.100% 0.366%UT 8 8 0 53.333% 57.143% 0.000% 255,415 255,415 0 56.467% 85.119% 0.000%VA 2 2 0 50.000% 66.667% 0.000% 154 154 0 12.748% 77.778% 0.000%VT 22 22 0 7.051% 7.801% 0.000% 7,604 7,604 0 2.916% 5.122% 0.000%WI 161 160 1 54.762% 54.983% 33.333% 1,091,022 988,004 103,018 47.729% 81.228% 9.632%WV 10 8 2 4.808% 7.619% 1.942% 8,178 1,153 7,025 0.807% 1.041% 0.779%WY 6 5 1 17.143% 17.857% 14.286% 35,810 28,960 6,850 28.358% 61.538% 8.647%Total 1,222 1,185 37 17.751% 19.144% 5.331% 9,163,346 4,652,946 4,510,400 19.323% 31.007% 13.914%

Percent of Population Served 

with At Least One Detection 


	


State

Number of Systems 

with At Least One Detection 


	


Percent of Systems 

with At Least One Detection 


	


Population Served by Systems 

with At Least One Detection 


	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53 (Revised Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 pCi/L 3,472 432 12.442% 11,709,681 2,438,570 20.825%


	
 3,472 1,008 29.032% 11,709,681 4,280,726 36.557%

> 5 pCi/L 421 14 3.325% 29,716,756 1,372,884 4.620%


	
 421 47 11.164% 29,716,756 3,100,164 10.432%

> 5 pCi/L 3,893 446 11.456% 41,426,437 3,811,454 9.201%


	
 3,893 1,055 27.100% 41,426,437 7,380,890 17.817%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53a (Revised Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 522 454 68 93.295% 92.731% 97.059% 0.01 0.04 0.01 0.47 0.47 0.49 1.01 1.01 0.86 4.45 4.45 1.83AL 36 11 25 94.444% 90.909% 96.000% 0.1 0.12 0.1 0.5 1.17 0.45 1.4 3.225 0.8 3.3 3.3 1.9ARAZ 610 435 175 18.689% 21.379% 12.000% 0.0008 0.0008 0.2 0.7 0.98 0.3 2.6 3.1 0.57 8.3 8.3 1.2CA 1,094 661 433 16.271% 18.759% 12.471% 0.053 0.16 0.053 0.934 1.035 0.82 2.8 3.9 1.4 11.03 11.03 3.4CO 870 663 207 75.862% 76.621% 73.430% 0.04 0.04 0.1 1 1.2 0.55 7.65 10.07 1.9 40.3 40.3 10CT 1,504 1,383 121 37.566% 39.407% 16.529% 0.1 0.1 1.01 1.5 1.5 1.5 4.9 4.92 2.385 56.66 56.66 3.75DE 6 5 1 66.667% 60.000% 100.000% 1.58 1.58 27.789 4.3 4.04 27.789 27.789 4.56 27.789 27.789 4.56 27.789FLGAHIIA 422 412 10 89.810% 91.505% 20.000% 0.6 0.6 0.8 2.9 3 0.9 5.4 5.4 1 11.2 11.2 1ID 154 147 7 29.221% 29.252% 28.571% 0.1 0.1 0.4 0.5 0.5 0.75 1.9 1.9 1.1 3 3 1.1IL 2,851 2,832 19 98.843% 98.976% 78.947% 0.1 0.1 0.13 3.507 3.55 1.57 10.8 10.84 8.1 32.84 32.84 9.1INKY 2 1 1 100.000% 100.000% 100.000% 0.25 0.25 2.6 1.425 0.25 2.6 2.6 0.25 2.6 2.6 0.25 2.6MAMD 279 219 60 59.140% 66.210% 33.333% 0.1 0.1 0.1 1.8 1.9 0.75 6.7 6.8 2.295 12.9 12.9 2.78ME 18 18 0 100.000% 100.000% 0.000% 0.26 0.26 1.508 1.508 19.32 19.32 21 21MIMNMO 697 696 1 99.570% 99.569% 100.000% 0.1 0.1 0.1 2.95 3 0.1 11.1 11.1 0.1 32.7 32.7 0.1MT 464 449 15 19.181% 19.376% 13.333% 0.2 0.2 0.6 0.7 0.7 0.7 3.1 3.1 0.8 6.4 6.4 0.8NC 2,815 2,583 232 54.210% 56.833% 25.000% 0.13 0.13 0.18 3.4 3.5 0.95 9.3 9.3 1.43 31.1 31.1 1.9ND 5 5 0 60.000% 60.000% 0.000% 0.166 0.166 1.15 1.15 1.5 1.5 1.5 1.5NE 130 126 4 45.385% 46.825% 0.000% 0.3 0.3 2.1 2.1 4.7 4.7 11.6 11.6NHNJ 1,489 1,146 343 73.674% 76.963% 62.682% 1 1 1 2.7 3.11 1.5 5.46 5.72 4.56 20.41 20.41 7.22NM 599 555 44 46.745% 46.486% 50.000% 0.01 0.01 0.04 0.4035 0.41 0.235 3.07 3.28 1.36 22.3 22.3 2.082NV 532 489 43 52.820% 50.102% 83.721% 0.0165 0.0165 0.079 0.461 0.431 0.6305 1.37 1.4 1.24 7.62 7.62 1.4771NY 1,362 1,166 196 84.875% 86.106% 77.551% 0.008 0.008 0.03 1.1015 1.18 0.8 4.12 4.2 3.2 22.4 22.4 9.02OH 50 49 1 48.000% 48.980% 0.000% 1.08 1.08 2.86 2.86 6.04 6.04 7.26 7.26OKOR 50 43 7 14.000% 16.279% 0.000% 0.3 0.3 0.74 0.74 1.85 1.85 1.85 1.85RI 29 24 5 24.138% 29.167% 0.000% 1.11 1.11 1.3 1.3 1.7 1.7 1.7 1.7SC 860 789 71 53.372% 56.274% 21.127% 1 1 1 3.5 3.5 2.3 8 8.1 5.4 33.6 33.6 6.1SD 25 25 0 96.000% 96.000% 0.000% 1 1 1 1 2.91 2.91 4 4TNTXUT 26 14 12 53.846% 92.857% 8.333% 113223443443VA 33 32 1 48.485% 50.000% 0.000% 0.671 0.671 1.59 1.59 4.44 4.44 4.55 4.55VT 143 117 26 87.413% 88.889% 80.769% 0.03 0.03 0.1 0.7 0.795 0.3 6.1 6.2 1.3 14.87 14.87 1.8WI 207 207 0 97.585% 97.585% 0.000% 0.03 0.03 3.85 3.85 6.7 6.7 14.8 14.8WV 90 73 17 94.444% 94.521% 94.118% 0.1 0.1 0.1 0.8 1 0.41 4.4 4.5 1.5 7 7 1.89WY 76 66 10 100.000% 100.000% 100.000% 0.2 0.2 0.6 1 1 1.6 3 2.5 3.05 5.9 5.9 3.1Total 18,050 15,895 2,155 64.781% 67.732% 43.016% 0.0008 0.0008 0.01 2 2.3 1 7.8 8.1 3 56.66 56.66 27.789

Maximum Detect 

Concentration (pCi/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (pCi/L) Median Detect Concentration (pCi/L) 90th Percentile Detect Concentration (pCi/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53b (Revised Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 141 118 23 92,837 70,944 21,893 92.908% 93.220% 91.304% 91.996% 91.086% 94.944%AL 11 8 3 1,051,258 38,578 1,012,680 90.909% 87.500% 100.000% 99.732% 92.706% 100.000%ARAZ 139 127 12 4,573,238 1,328,714 3,244,524 34.532% 31.496% 66.667% 37.946% 25.561% 43.018%CA 163 118 45 9,301,445 1,992,068 7,309,377 32.515% 31.356% 35.556% 28.412% 53.616% 21.543%CO 204 153 51 3,169,671 253,727 2,915,944 83.333% 86.275% 74.510% 46.502% 94.061% 42.363%CT 283 265 18 1,463,874 139,544 1,324,330 69.258% 72.075% 27.778% 18.964% 78.576% 12.683%DE 3 2 1 111,360 6,090 105,270 66.667% 50.000% 100.000% 99.919% 98.522% 100.000%FLGAHIIA 170 166 4 557,475 252,579 304,896 88.235% 89.157% 50.000% 56.854% 67.187% 48.295%ID 79 77 2 610,810 421,610 189,200 32.911% 32.468% 50.000% 65.817% 51.236% 98.309%IL 472 461 11 2,256,473 1,679,294 577,179 97.881% 98.482% 72.727% 96.420% 99.758% 86.707%INKY 2 1 1 101,482 84,935 16,547 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%MAMD 96 77 19 2,527,642 519,882 2,007,760 58.333% 63.636% 36.842% 89.884% 85.004% 91.148%ME 11 11 0 1,746 1,746 0 100.000% 100.000% 0.000% 100.000% 100.000% 0.000%MIMNMO 210 209 1 211,284 211,261 23 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%MT 167 160 7 69,849 54,111 15,738 26.347% 26.250% 28.571% 41.840% 41.054% 44.542%NC 404 363 41 2,816,439 436,906 2,379,533 51.485% 53.168% 36.585% 69.181% 58.076% 71.220%ND 3 3 0 269 269 0 100.000% 100.000% 0.000% 100.000% 100.000% 0.000%NE 50 49 1 623,950 111,786 512,164 48.000% 48.980% 0.000% 5.290% 29.524% 0.000%NHNJ 125 95 30 6,565,156 1,633,380 4,931,776 87.200% 86.316% 90.000% 87.086% 95.974% 84.143%NM 283 258 25 1,363,603 1,122,055 241,548 53.004% 51.938% 64.000% 47.375% 40.005% 81.607%NV 86 81 5 464,030 155,491 308,539 55.814% 54.321% 80.000% 94.789% 84.641% 99.903%NY 362 298 64 979,416 300,365 679,051 88.122% 89.597% 81.250% 69.172% 61.817% 72.425%OH 27 26 1 33,974 18,774 15,200 51.852% 53.846% 0.000% 21.466% 38.846% 0.000%OKOR 28 22 6 43,482 36,292 7,190 21.429% 27.273% 0.000% 21.899% 26.237% 0.000%RI 6 5 1 83,717 32,967 50,750 66.667% 80.000% 0.000% 39.170% 99.469% 0.000%SC 150 128 22 1,225,431 205,071 1,020,360 46.667% 52.344% 13.636% 15.767% 62.744% 6.326%SD 11 11 0 16,869 16,869 0 90.909% 90.909% 0.000% 12.644% 12.644% 0.000%TNTXUT 8 7 1 206,396 54,136 152,260 87.500% 85.714% 100.000% 99.855% 99.446% 100.000%VA 17 16 1 133,660 4,708 128,952 52.941% 56.250% 0.000% 1.491% 42.332% 0.000%VT 63 53 10 160,030 23,036 136,994 88.889% 88.679% 90.000% 64.017% 93.775% 59.013%WI 61 61 0 489,065 489,065 0 98.361% 98.361% 0.000% 99.775% 99.775% 0.000%WV 38 26 12 41,652 7,642 34,010 94.737% 92.308% 100.000% 99.400% 96.729% 100.000%WY 20 17 3 78,854 5,786 73,068 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%Total 3,893 3,472 421 41,426,437 11,709,681 29,716,756 69.972% 71.083% 60.808% 56.754% 68.876% 51.978%

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting Percent of Systems with At Least One Detection Total Population Served by Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53c (Revised Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ARAZ 2 2 0 1.439% 1.575% 0.000% 63,865 63,865 0 1.396% 4.807% 0.000%CA 4 4 0 2.454% 3.390% 0.000% 17,752 17,752 0 0.191% 0.891% 0.000%CO 39 36 3 19.118% 23.529% 5.882% 49,240 42,290 6,950 1.553% 16.668% 0.238%CT 17 17 0 6.007% 6.415% 0.000% 3,149 3,149 0 0.215% 2.257% 0.000%DE 1 0 1 33.333% 0.000% 100.000% 105,270 0 105,270 94.531% 0.000% 100.000%FLGAHIIA 21 21 0 12.353% 12.651% 0.000% 44,955 44,955 0 8.064% 17.798% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 132 130 2 27.966% 28.200% 18.182% 1,050,977 860,191 190,786 46.576% 51.223% 33.055%INKY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MAMD 4 4 0 4.167% 5.195% 0.000% 250,026 250,026 0 9.892% 48.093% 0.000%ME 2 2 0 18.182% 18.182% 0.000% 163 163 0 9.336% 9.336% 0.000%MIMNMO 34 34 0 16.190% 16.268% 0.000% 69,634 69,634 0 32.958% 32.961% 0.000%MT 1 1 0 0.599% 0.625% 0.000% 540 540 0 0.773% 0.998% 0.000%NC 57 57 0 14.109% 15.702% 0.000% 60,229 60,229 0 2.138% 13.785% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 4.000% 4.082% 0.000% 1,833 1,833 0 0.294% 1.640% 0.000%NHNJ 42 38 4 33.600% 40.000% 13.333% 1,888,978 862,698 1,026,280 28.773% 52.817% 20.810%NM 3 3 0 1.060% 1.163% 0.000% 2,840 2,840 0 0.208% 0.253% 0.000%NV 1 1 0 1.163% 1.235% 0.000% 663 663 0 0.143% 0.426% 0.000%NY 25 22 3 6.906% 7.383% 4.688% 11,670 8,622 3,048 1.192% 2.871% 0.449%OH 3 3 0 11.111% 11.538% 0.000% 852 852 0 2.508% 4.538% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 27 26 1 18.000% 20.313% 4.545% 74,993 34,443 40,550 6.120% 16.796% 3.974%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TNTXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 5 5 0 7.937% 9.434% 0.000% 865 865 0 0.541% 3.755% 0.000%WI 20 20 0 32.787% 32.787% 0.000% 111,935 111,935 0 22.888% 22.888% 0.000%WV 2 2 0 5.263% 7.692% 0.000% 280 280 0 0.672% 3.664% 0.000%WY 2 2 0 10.000% 11.765% 0.000% 745 745 0 0.945% 12.876% 0.000%

Total 446 432 14 11.456% 12.442% 3.325% 3,811,454 2,438,570 1,372,884 9.201% 20.825% 4.620%

Percent of Population Served 

with At Least One Detection 

> 5 pCi/L

State

Number of Systems 

with At Least One Detection 

> 5 pCi/L

Percent of Systems 

with At Least One Detection 

> 5 pCi/L

Population Served by Systems 

with At Least One Detection 

> 5 pCi/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A53d (Revised Rule). Radium-226 228 – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 3 3 0 2.128% 2.542% 0.000% 560 560 0 0.603% 0.789% 0.000%AL 2 2 0 18.182% 25.000% 0.000% 11,721 11,721 0 1.115% 30.383% 0.000%ARAZ 9 9 0 6.475% 7.087% 0.000% 137,300 137,300 0 3.002% 10.333% 0.000%CA 11 9 2 6.748% 7.627% 4.444% 482,626 190,511 292,115 5.189% 9.563% 3.996%CO 56 49 7 27.451% 32.026% 13.725% 230,225 103,211 127,014 7.263% 40.678% 4.356%CT 90 88 2 31.802% 33.208% 11.111% 142,649 43,702 98,947 9.745% 31.318% 7.471%DE 2 1 1 66.667% 50.000% 100.000% 111,270 6,000 105,270 99.919% 98.522% 100.000%FLGAHIIA 96 96 0 56.471% 57.831% 0.000% 141,891 141,891 0 25.452% 56.177% 0.000%ID 1 1 0 1.266% 1.299% 0.000% 94 94 0 0.015% 0.022% 0.000%IL 265 262 3 56.144% 56.833% 27.273% 1,410,014 1,212,402 197,612 62.488% 72.197% 34.238%INKY 1 0 1 50.000% 0.000% 100.000% 16,547 0 16,547 16.305% 0.000% 100.000%MAMD 13 12 1 13.542% 15.584% 5.263% 270,211 265,111 5,100 10.690% 50.994% 0.254%ME 2 2 0 18.182% 18.182% 0.000% 163 163 0 9.336% 9.336% 0.000%MIMNMO 61 61 0 29.048% 29.187% 0.000% 98,354 98,354 0 46.551% 46.556% 0.000%MT 6 6 0 3.593% 3.750% 0.000% 865 865 0 1.238% 1.599% 0.000%NC 111 111 0 27.475% 30.579% 0.000% 167,069 167,069 0 5.932% 38.239% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 6 6 0 12.000% 12.245% 0.000% 2,301 2,301 0 0.369% 2.058% 0.000%NHNJ 73 61 12 58.400% 64.211% 40.000% 3,031,317 1,270,041 1,761,276 46.173% 77.755% 35.713%NM 17 17 0 6.007% 6.589% 0.000% 93,899 93,899 0 6.886% 8.368% 0.000%NV 4 4 0 4.651% 4.938% 0.000% 26,215 26,215 0 5.649% 16.859% 0.000%NY 96 82 14 26.519% 27.517% 21.875% 244,030 26,341 217,689 24.916% 8.770% 32.058%OH 7 7 0 25.926% 26.923% 0.000% 2,862 2,862 0 8.424% 15.244% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 53 51 2 35.333% 39.844% 9.091% 154,547 98,381 56,166 12.612% 47.974% 5.505%SD 4 4 0 36.364% 36.364% 0.000% 775 775 0 4.594% 4.594% 0.000%TNTXUT 3 2 1 37.500% 28.571% 100.000% 155,310 3,050 152,260 75.249% 5.634% 100.000%VA 4 4 0 23.529% 25.000% 0.000% 544 544 0 0.407% 11.555% 0.000%VT 11 11 0 17.460% 20.755% 0.000% 2,324 2,324 0 1.452% 10.089% 0.000%WI 38 38 0 62.295% 62.295% 0.000% 373,042 373,042 0 76.277% 76.277% 0.000%WV 4 4 0 10.526% 15.385% 0.000% 532 532 0 1.277% 6.962% 0.000%WY 6 5 1 30.000% 29.412% 33.333% 71,633 1,465 70,168 90.843% 25.320% 96.031%Total 1,055 1,008 47 27.100% 29.032% 11.164% 7,380,890 4,280,726 3,100,164 17.817% 36.557% 10.432%

Percent of Population Served 

with At Least One Detection 


	


State

Number of Systems 

with At Least One Detection 


	


Percent of Systems 

with At Least One Detection 


	


Population Served by Systems 

with At Least One Detection 


	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A54. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.05 mg/L 44,924 63 0.140% 85,462,006 123,164 0.144%

	
 44,924 252 0.561% 85,462,006 750,440 0.878%

> 0.05 mg/L 4,001 2 0.050% 144,401,405 101,652 0.070%

	
 4,001 28 0.700% 144,401,405 4,034,609 2.794%

> 0.05 mg/L 48,925 65 0.133% 229,863,411 224,816 0.098%

	
 48,925 280 0.572% 229,863,411 4,785,049 2.082%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A54a. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 874 617 257 3.204% 3.241% 3.113% 0.00112 0.00131 0.00112 0.00346 0.00374 0.0025 0.00631 0.00816 0.00491 0.02 0.02 0.00491AL 2,643 1,794 849 1.400% 0.669% 2.945% 0.0002 0.00103 0.0002 0.002 0.0021 0.002 0.0063 0.01 0.0035 0.01 0.01 0.01AR 2,180 1,516 664 0.367% 0.462% 0.151% 0.005 0.005 0.0059 0.0062 0.0064 0.0059 0.04 0.04 0.0059 0.04 0.04 0.0059AZ 6,317 4,988 1,329 11.065% 10.866% 11.813% 0.0006 0.0006 0.001 0.0043 0.005 0.0031 0.01 0.01 0.0057 0.42 0.42 0.04CA 35,322 21,147 14,175 10.011% 12.900% 5.700% 7.6E-05 7.6E-05 0.00012 0.005 0.005 0.005 0.02 0.02 0.01 0.49 0.49 0.2CO 4,423 2,367 2,056 19.127% 24.546% 12.889% 0.00006 0.0002 0.00006 0.0043 0.005 0.003 0.02 0.02 0.01 0.18 0.18 0.04CT 2,595 1,873 722 2.235% 2.723% 0.970% 0.0002 0.0003 0.0002 0.006 0.006 0.003 0.01 0.01 0.01 0.05 0.05 0.01DE 686 638 48 28.280% 29.467% 12.500% 0.0001 0.0001 0.0005 0.0005 0.0005 0.0006 0.0026 0.0027 0.0007 0.02 0.02 0.0007FL 2,141 2,072 69 18.449% 18.678% 11.594% 0.0001 0.0001 0.001 0.002 0.002 0.003 0.006 0.006 0.004 0.03 0.03 0.004GA 2,700 2,377 323 0.037% 0.042% 0.000% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02HI 1,178 1,116 62 0.170% 0.179% 0.000% 0.005 0.005 0.0055 0.0055 0.006 0.006 0.006 0.006IA 1,511 1,249 262 3.508% 4.003% 1.145% 0.001 0.001 0.002 0.02 0.02 0.009 0.03 0.03 0.01 0.05 0.05 0.01ID 2,652 2,382 270 4.563% 4.618% 4.074% 0.0005 0.0005 0.001 0.003 0.003 0.0026 0.01 0.01 0.0077 0.03 0.03 0.01IL 3,392 2,991 401 13.738% 12.638% 21.945% 0.001 0.001 0.001 0.0021 0.00215 0.002 0.006 0.0066 0.005 0.06 0.06 0.01IN 4,704 4,221 483 3.550% 3.293% 5.797% 0.0008 0.0008 0.0012 0.003 0.003 0.003 0.01 0.01 0.0091 0.03 0.03 0.01KY 1,778 537 1,241 6.805% 5.587% 7.333% 0.00024 0.0005 0.00024 0.003 0.003 0.0022 0.006 0.0085 0.0059 0.01 0.01 0.01MA 2,941 1,978 963 3.196% 3.387% 2.804% 0.00086 0.00086 0.001 0.003 0.003 0.003 0.006 0.007 0.005 0.01 0.01 0.01MD 5,085 3,969 1,116 2.852% 1.159% 8.871% 0.00034 0.0006 0.00034 0.001 0.004 0.001 0.02 0.02 0.007 0.05 0.02 0.05ME 2,703 2,305 398 10.877% 11.584% 6.784% 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.01 0.01 0.01MI 6,119 5,945 174 31.786% 30.463% 77.011% 0.00015 0.00015 0.0005 0.001 0.001 0.001 0.003 0.003 0.003 0.14 0.14 0.04MN 3,329 3,280 49 0.421% 0.427% 0.000% 0.00516 0.00516 0.00657 0.00657 0.00924 0.00924 0.00985 0.00985MO 5,705 4,928 777 3.996% 4.058% 3.604% 0.001 0.001 0.00104 0.00193 0.00199 0.00174 0.0059 0.00597 0.0026 0.02 0.02 0.00638MT 2,756 2,473 283 5.806% 5.985% 4.240% 0.0003 0.0003 0.001 0.003 0.003 0.0025 0.01 0.01 0.006 0.05 0.05 0.01NC 9,233 7,799 1,434 1.700% 1.769% 1.325% 0.0004 0.0004 0.001 0.006 0.0065 0.005 0.02 0.02 0.02 0.18 0.18 0.02ND 357 313 44 70.588% 69.329% 79.545% 0.00102 0.00102 0.00107 0.00277 0.00292 0.00188 0.00948 0.00948 0.01 0.09 0.09 0.03NE 1,940 1,854 86 36.649% 38.080% 5.814% 0.005 0.005 0.00509 0.00955 0.00962 0.00542 0.04 0.04 0.00646 0.2 0.2 0.00646NH 2,930 2,766 164 0.137% 0.145% 0.000% 0.0069 0.0069 0.04 0.04 0.1 0.1 0.1 0.1NJ 6,574 5,853 721 4.198% 4.186% 4.300% 0.0003 0.0003 0.0004 0.003 0.003 0.002 0.007 0.007 0.004 0.17 0.17 0.03NM 3,540 3,214 326 40.480% 41.661% 28.834% 0.0004 0.0004 0.0006 0.0028 0.0029 0.00225 0.01 0.01 0.0053 0.23 0.23 0.02NV 1,870 1,292 578 26.898% 30.495% 18.858% 0.0001 0.0001 0.00022 0.002 0.002 0.002 0.006 0.00665 0.005 0.06 0.06 0.01NY 3,389 2,535 854 4.574% 4.379% 5.152% 0.00019 0.00019 0.001 0.002 0.0027 0.00183 0.007 0.0082 0.00398 0.03 0.03 0.01OH 4,080 3,447 633 4.534% 4.845% 2.844% 0.00167 0.00167 0.002 0.0047 0.0049 0.004 0.0092 0.00932 0.006 0.04 0.04 0.0071OK 424 350 74 16.274% 14.286% 25.676% 0.0015 0.0015 0.0021 0.01 0.025 0.01 0.06 0.075 0.03 0.19 0.19 0.03OR 1,313 952 361 2.437% 2.941% 1.108% 0.00061 0.00069 0.00061 0.00201 0.00301 0.0015 0.01 0.01 0.0067 0.01 0.01 0.0067RI 888 658 230 0.338% 0.456% 0.000% 0.005 0.005 0.01 0.01 0.01 0.01 0.01 0.01SC 3,443 2,980 463 1.888% 2.148% 0.216% 0.002 0.002 0.0031 0.0031 0.00305 0.0031 0.0054 0.0054 0.0031 0.02 0.02 0.0031SD 388 359 29 37.629% 37.326% 41.379% 0.0008 0.0008 0.001 0.003 0.00345 0.0015 0.009 0.0092 0.0018 0.02 0.02 0.002TN 1,656 483 1,173 7.065% 2.277% 9.037% 0.00021 0.001 0.00021 0.0015 0.0015 0.0015 0.003 0.0029 0.003 0.01 0.01 0.01TX 14,806 12,227 2,579 23.680% 20.790% 37.379% 0.0012 0.0012 0.002 0.0048 0.0053 0.0041 0.01 0.02 0.01 0.19 0.19 0.04UT 6,996 5,459 1,537 60.206% 64.096% 46.389% 0.0001 0.0002 0.0001 0.00178 0.0019 0.0013 0.0047 0.0048 0.0046 0.18 0.18 0.01VA 2,802 2,193 609 0.678% 0.775% 0.328% 0.002 0.002 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01VT 2,080 1,756 324 0.529% 0.626% 0.000% 0.0009 0.0009 0.002 0.002 0.04 0.04 0.38 0.38WI 7,007 6,835 172 7.250% 7.403% 1.163% 0.00035 0.00035 0.0009 0.0014 0.0014 0.00145 0.00385 0.00385 0.002 0.05 0.05 0.002WV 1,112 424 688 4.137% 7.547% 2.035% 0.00033 0.00063 0.00033 0.005 0.005 0.00275 0.01 0.01 0.0051 0.01 0.01 0.01WY 1,122 875 247 8.734% 9.943% 4.453% 0.0011 0.0011 0.0023 0.006 0.006 0.006 0.01 0.01 0.007 0.08 0.08 0.009Total 181,684 141,387 40,297 12.175% 12.790% 10.016% 0.00006 7.6E-05 0.00006 0.003 0.003 0.003 0.01 0.01 0.0087 0.49 0.49 0.2

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A54b. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 492 391 101 546,472 210,251 336,221 5.081% 4.859% 5.941% 42.405% 2.183% 67.558%AL 352 279 73 4,701,100 1,463,066 3,238,034 7.955% 3.943% 23.288% 26.905% 1.970% 38.171%AR 453 381 72 2,452,800 909,774 1,543,026 1.104% 1.050% 1.389% 1.413% 2.809% 0.589%AZ 1,050 1,002 48 6,162,056 2,791,465 3,370,591 26.762% 25.150% 60.417% 65.396% 37.701% 88.332%CA 3,812 3,289 523 36,243,379 13,413,210 22,830,169 18.258% 18.030% 19.694% 56.543% 57.515% 55.972%CO 838 617 221 4,998,506 533,275 4,465,231 41.169% 39.708% 45.249% 40.000% 49.461% 38.871%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 4.444% 4.156% 12.821% 17.810% 6.003% 19.744%DE 281 278 3 679,823 398,423 281,400 47.331% 46.763% 100.000% 73.448% 54.695% 100.000%FL 1,333 1,307 26 17,371,144 15,125,102 2,246,042 21.230% 21.117% 26.923% 45.578% 48.546% 25.593%GA 1,587 1,473 114 7,241,184 1,348,853 5,892,331 0.063% 0.068% 0.000% 0.002% 0.009% 0.000%HI 107 95 12 1,303,767 1,249,139 54,628 1.869% 2.105% 0.000% 0.466% 0.487% 0.000%IA 966 933 33 2,499,860 1,391,234 1,108,626 3.209% 3.001% 9.091% 11.162% 2.880% 21.556%ID 894 847 47 1,048,642 805,767 242,875 7.606% 7.556% 8.511% 20.501% 24.640% 6.770%IL 1,490 1,387 103 9,168,134 2,968,062 6,200,072 21.409% 19.827% 42.718% 22.588% 32.118% 18.025%IN 1,623 1,574 49 4,980,057 2,619,602 2,360,455 7.209% 6.607% 26.531% 23.677% 27.157% 19.814%KY 242 93 149 4,602,489 375,460 4,227,029 33.471% 24.731% 38.926% 51.189% 32.276% 52.869%MA 676 558 118 8,525,575 1,718,151 6,807,424 8.876% 8.602% 10.169% 51.067% 9.521% 61.553%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 4.913% 3.711% 22.059% 46.779% 33.269% 50.241%ME 806 752 54 727,707 292,103 435,604 26.799% 26.064% 37.037% 26.751% 35.265% 21.043%MI 2,993 2,941 52 6,681,481 1,889,150 4,792,331 40.194% 39.510% 78.846% 85.026% 59.186% 95.212%MN 1,459 1,432 27 3,959,159 2,725,622 1,233,537 0.685% 0.698% 0.000% 2.817% 4.091% 0.000%MO 1,420 1,343 77 3,006,718 1,692,257 1,314,461 10.986% 10.424% 20.779% 15.734% 18.082% 12.711%MT 846 787 59 757,540 365,141 392,399 13.239% 13.469% 10.169% 25.040% 28.164% 22.132%NC 2,283 2,144 139 6,973,518 1,708,352 5,265,166 5.344% 5.084% 9.353% 4.849% 7.050% 4.135%ND 217 190 27 563,069 257,844 305,225 74.194% 73.684% 77.778% 81.228% 73.501% 87.757%NE 731 720 11 1,449,290 672,810 776,480 41.313% 41.389% 36.364% 80.227% 62.655% 95.452%NH 1,216 1,175 41 942,517 392,718 549,799 0.329% 0.340% 0.000% 0.204% 0.489% 0.000%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 11.790% 11.219% 32.432% 40.865% 43.179% 39.612%NM 724 685 39 1,667,433 1,400,885 266,548 55.110% 55.912% 41.026% 45.800% 42.977% 60.635%NV 324 304 20 970,526 280,727 689,799 51.543% 50.329% 70.000% 91.351% 73.576% 98.585%NY 1,574 1,333 241 11,201,957 1,222,509 9,979,448 8.005% 6.752% 14.938% 2.591% 8.113% 1.915%OH 1,917 1,792 125 10,218,949 3,124,012 7,094,937 7.929% 7.924% 8.000% 6.947% 3.415% 8.502%OK 202 175 27 749,266 276,712 472,554 10.891% 10.857% 11.111% 31.910% 29.516% 33.312%OR 731 610 121 2,770,064 486,818 2,283,246 3.830% 3.934% 3.306% 30.564% 11.062% 34.722%RI 143 134 9 913,584 173,606 739,978 1.399% 1.493% 0.000% 4.663% 24.538% 0.000%SC 823 758 65 3,468,333 809,806 2,658,527 4.010% 4.222% 1.538% 1.229% 3.605% 0.505%SD 235 224 11 328,972 237,011 91,961 46.383% 45.982% 54.545% 48.679% 59.749% 20.149%TN 350 161 189 5,683,572 1,460,816 4,222,756 9.143% 6.832% 11.111% 14.824% 4.976% 18.231%TX 4,888 4,547 341 25,060,220 9,275,719 15,784,501 31.015% 28.172% 68.915% 62.609% 31.420% 80.938%UT 507 457 50 2,543,652 1,686,017 857,635 76.726% 78.775% 58.000% 82.074% 85.922% 74.508%VA 1,581 1,413 168 4,803,093 634,027 4,169,066 1.012% 0.991% 1.190% 2.408% 1.279% 2.580%VT 599 557 42 490,639 226,871 263,768 1.669% 1.795% 0.000% 0.310% 0.671% 0.000%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 19.035% 19.135% 10.000% 13.114% 21.178% 1.899%WV 451 290 161 1,415,477 234,687 1,180,790 8.204% 9.310% 6.211% 13.121% 10.236% 13.695%WY 304 255 49 446,184 129,168 317,016 14.803% 15.686% 10.204% 40.431% 39.599% 40.770%Total 48,925 44,924 4,001 229,863,411 85,462,006 144,401,405 17.284% 16.715% 23.669% 37.048% 34.217% 38.724%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A54c. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 3 3 0 0.286% 0.299% 0.000% 6,432 6,432 0 0.104% 0.230% 0.000%CA 16 14 2 0.420% 0.426% 0.382% 138,673 37,021 101,652 0.383% 0.276% 0.445%CO 4 4 0 0.477% 0.648% 0.000% 3,725 3,725 0 0.075% 0.699% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.067% 0.072% 0.000% 60 60 0 0.001% 0.002% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 1 1 0 0.033% 0.034% 0.000% 263 263 0 0.004% 0.014% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 4 4 0 0.175% 0.187% 0.000% 13,705 13,705 0 0.197% 0.802% 0.000%ND 1 1 0 0.461% 0.526% 0.000% 761 761 0 0.135% 0.295% 0.000%NE 8 8 0 1.094% 1.111% 0.000% 3,643 3,643 0 0.251% 0.541% 0.000%NH 2 2 0 0.164% 0.170% 0.000% 98 98 0 0.010% 0.025% 0.000%NJ 1 1 0 0.073% 0.075% 0.000% 145 145 0 0.002% 0.005% 0.000%NM 5 5 0 0.691% 0.730% 0.000% 1,095 1,095 0 0.066% 0.078% 0.000%NV 2 2 0 0.617% 0.658% 0.000% 593 593 0 0.061% 0.211% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 5 5 0 2.475% 2.857% 0.000% 46,475 46,475 0 6.203% 16.795% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 7 7 0 0.143% 0.154% 0.000% 702 702 0 0.003% 0.008% 0.000%UT 3 3 0 0.592% 0.656% 0.000% 8,200 8,200 0 0.322% 0.486% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 1 1 0 0.167% 0.180% 0.000% 168 168 0 0.034% 0.074% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 1 1 0 0.329% 0.392% 0.000% 78 78 0 0.017% 0.060% 0.000%Total 65 63 2 0.133% 0.140% 0.050% 224,816 123,164 101,652 0.098% 0.144% 0.070%

Percent of Population Served 

with At Least One Detection 

> 0.05 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.05 mg/L

Percent of Systems 

with At Least One Detection 

> 0.05 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.05 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A54d. Selenium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 1 1 0 0.221% 0.262% 0.000% 37 37 0 0.002% 0.004% 0.000%AZ 8 6 2 0.762% 0.599% 4.167% 318,655 18,655 300,000 5.171% 0.668% 8.901%CA 47 39 8 1.233% 1.186% 1.530% 1,029,063 438,560 590,503 2.839% 3.270% 2.587%CO 19 17 2 2.267% 2.755% 0.905% 13,363 13,003 360 0.267% 2.438% 0.008%CT 4 4 0 0.342% 0.354% 0.000% 289 289 0 0.011% 0.076% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 2 2 0 0.150% 0.153% 0.000% 106 106 0 0.001% 0.001% 0.000%GA 1 1 0 0.063% 0.068% 0.000% 120 120 0 0.002% 0.009% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 3 3 0 0.311% 0.322% 0.000% 3,218 3,218 0 0.129% 0.231% 0.000%ID 3 3 0 0.336% 0.354% 0.000% 465 465 0 0.044% 0.058% 0.000%IL 4 4 0 0.268% 0.288% 0.000% 24,434 24,434 0 0.267% 0.823% 0.000%IN 2 2 0 0.123% 0.127% 0.000% 13,134 13,134 0 0.264% 0.501% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 13 7 6 1.252% 0.722% 8.824% 1,894,473 9,666 1,884,807 37.720% 0.944% 47.142%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 4 3 1 0.134% 0.102% 1.923% 297,792 438 297,354 4.457% 0.023% 6.205%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 5 5 0 0.591% 0.635% 0.000% 380 380 0 0.050% 0.104% 0.000%NC 11 10 1 0.482% 0.466% 0.719% 24,225 17,725 6,500 0.347% 1.038% 0.123%ND 4 3 1 1.843% 1.579% 3.704% 6,592 2,076 4,516 1.171% 0.805% 1.480%NE 34 34 0 4.651% 4.722% 0.000% 39,415 39,415 0 2.720% 5.858% 0.000%NH 2 2 0 0.164% 0.170% 0.000% 98 98 0 0.010% 0.025% 0.000%NJ 2 1 1 0.146% 0.075% 2.703% 676,399 145 676,254 8.714% 0.005% 13.429%NM 13 13 0 1.796% 1.898% 0.000% 14,256 14,256 0 0.855% 1.018% 0.000%NV 3 3 0 0.926% 0.987% 0.000% 1,353 1,353 0 0.139% 0.482% 0.000%NY 2 2 0 0.127% 0.150% 0.000% 2,000 2,000 0 0.018% 0.164% 0.000%OH 7 7 0 0.365% 0.391% 0.000% 1,371 1,371 0 0.013% 0.044% 0.000%OK 7 6 1 3.465% 3.429% 3.704% 176,806 51,375 125,431 23.597% 18.566% 26.543%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 1 0 0.122% 0.132% 0.000% 200 200 0 0.006% 0.025% 0.000%SD 1 1 0 0.426% 0.446% 0.000% 33 33 0 0.010% 0.014% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 61 56 5 1.248% 1.232% 1.466% 196,331 47,447 148,884 0.783% 0.512% 0.943%UT 8 8 0 1.578% 1.751% 0.000% 48,401 48,401 0 1.903% 2.871% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 2 2 0 0.334% 0.359% 0.000% 293 293 0 0.060% 0.129% 0.000%WI 4 4 0 0.219% 0.222% 0.000% 1,605 1,605 0 0.040% 0.068% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 2 2 0 0.658% 0.784% 0.000% 142 142 0 0.032% 0.110% 0.000%Total 280 252 28 0.572% 0.561% 0.700% 4,785,049 750,440 4,034,609 2.082% 0.878% 2.794%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A55. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 4 μg/L 33,478 4 0.012% 73,412,761 2,408 0.003%	
 33,478 5 0.015% 73,412,761 3,108 0.004%> 4 μg/L 3,352 12 0.358% 123,573,744 120,751 0.098%	
 3,352 29 0.865% 123,573,744 725,922 0.587%> 4 μg/L 36,830 16 0.043% 196,986,505 123,159 0.063%	
 36,830 34 0.092% 196,986,505 729,030 0.370%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A55a. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 51 15 36 0.000% 0.000% 0.000%AL 567 411 156 0.882% 0.000% 3.205% 0.08 0.08 0.19 0.19 0.22 0.22 0.22 0.22AR 1,658 1,412 246 0.121% 0.000% 0.813% 0.03 0.03 0.04 0.04 0.05 0.05 0.05 0.05AZ 7,021 5,446 1,575 0.114% 0.147% 0.000% 0.09 0.09 0.13 0.13 0.7 0.7 0.7 0.7CA 23,217 14,840 8,377 0.134% 0.020% 0.334% 0.02 0.21 0.02 0.17 0.28 0.135 3.18 1.3 3.18 3.18 1.3 3.18CO 2,486 1,813 673 0.322% 0.165% 0.743% 3.9 3.9 5.6 5.95 5.7 6.3 11 6.2 11 11 6.2 11CT 1,316 1,003 313 0.000% 0.000% 0.000%DE 1,266 1,221 45 0.000% 0.000% 0.000%FL 2,398 2,328 70 0.459% 0.473% 0.000% 0.01 0.01 0.01 0.01 0.01 0.01 0.24 0.24GA 1,477 1,396 81 0.135% 0.000% 2.469% 8 8 8 8 8 8 8 8HI 2,101 2,004 97 0.095% 0.100% 0.000% 0.08 0.08 0.085 0.085 0.09 0.09 0.09 0.09IA 1,739 1,603 136 0.115% 0.062% 0.735% 0.29 0.3 0.29 0.295 0.3 0.29 0.3 0.3 0.29 0.3 0.3 0.29ID 2,621 2,337 284 0.000% 0.000% 0.000%IL 4,178 3,175 1,003 1.915% 0.000% 7.976% 0.4 0.4 0.815 0.815 2.4 2.4 7.8 7.8IN 2,448 2,202 246 1.511% 0.045% 14.634% 0.08 0.75 0.08 0.34 0.75 0.3 1 0.75 1 3.9 0.75 3.9KY 1,873 436 1,437 5.392% 0.000% 7.029% 0.02 0.02 0.27 0.27 0.93 0.93 7.2 7.2MA 3,020 2,235 785 0.099% 0.045% 0.255% 0.07 0.13 0.07 0.07 0.13 0.07 0.13 0.13 0.07 0.13 0.13 0.07MD 2,820 1,732 1,088 2.270% 0.520% 5.055% 0.01 0.3 0.01 0.215 1.3 0.2 1.1 1.4 0.8 3.2 1.4 3.2ME 456 391 65 0.000% 0.000% 0.000%MI 6,923 6,423 500 0.058% 0.000% 0.800% 0.2 0.2 0.25 0.25 0.3 0.3 0.3 0.3MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 9,521 5,075 4,446 0.357% 0.611% 0.067% 0.5 0.5 0.62 1.025 1.42 0.77 2.7 2.7 1 4.52 4.52 1MT 3,018 2,710 308 0.000% 0.000% 0.000%NC 13,271 12,108 1,163 0.377% 0.140% 2.837% 0.07 0.07 0.07 0.235 0.28 0.21 0.785 1.23 0.56 4.82 1.68 4.82ND 407 341 66 0.000% 0.000% 0.000%NE 4,478 4,130 348 0.246% 0.048% 2.586% 0.1 0.1 0.11 0.16 0.105 0.17 0.24 0.11 0.25 0.25 0.11 0.25NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 195 176 19 0.513% 0.568% 0.000% 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12NM 4,525 4,262 263 0.022% 0.023% 0.000% 4.16 4.16 4.16 4.16 4.16 4.16 4.16 4.16NV 1,606 1,174 432 0.000% 0.000% 0.000%NY 2,925 2,187 738 0.034% 0.000% 0.136% 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04OH 7,557 4,178 3,379 6.352% 0.239% 13.909% 0.05 0.05 0.05 0.27 0.095 0.27 0.86 0.63 0.87 12.4 0.78 12.4OKOR 2,057 1,573 484 0.000% 0.000% 0.000%RI 926 633 293 3.672% 0.474% 10.580% 0.1 0.15 0.1 0.15 0.15 0.15 0.51 0.21 0.51 0.89 0.21 0.89SC 2,906 2,516 390 0.000% 0.000% 0.000%SD 960 851 109 0.000% 0.000% 0.000%TN 214 42 172 0.935% 2.381% 0.581% 0.07 1.7 0.07 0.885 1.7 0.07 1.7 1.7 0.07 1.7 1.7 0.07TX 11,075 5,282 5,793 1.309% 0.076% 2.434% 0.1 0.14 0.1 0.24 0.205 0.24 0.48 0.3 0.48 1.66 0.3 1.66UT 7,084 5,903 1,181 0.014% 0.017% 0.000% 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3VA 504 178 326 0.000% 0.000% 0.000%VT 1,315 1,113 202 0.152% 0.090% 0.495% 0.07 0.07 0.17 0.12 0.07 0.17 0.17 0.07 0.17 0.17 0.07 0.17WI 3,190 3,097 93 0.251% 0.258% 0.000% 0.07 0.07 0.115 0.115 0.27 0.27 0.27 0.27WV 650 338 312 2.000% 2.367% 1.603% 0.03 0.03 0.03 0.05 0.04 0.07 0.5 0.5 0.5 0.5 0.5 0.5WY 1,282 971 311 0.000% 0.000% 0.000%Total 158,256 119,755 38,501 0.722% 0.106% 2.639% 0.01 0.01 0.01 0.27 0.3 0.26 1.1 2.46 1 12.4 6.2 12.4

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A55b. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 12 7 5 245,571 13,636 231,935 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 179 132 47 2,794,595 634,014 2,160,581 2.235% 0.000% 8.511% 3.714% 0.000% 4.803%AR 454 382 72 2,453,348 910,322 1,543,026 0.441% 0.000% 2.778% 0.804% 0.000% 1.279%AZ 933 885 48 6,077,602 2,707,011 3,370,591 0.750% 0.791% 0.000% 0.043% 0.097% 0.000%CA 2,409 2,030 379 34,891,367 12,961,658 21,929,709 0.706% 0.148% 3.694% 2.342% 0.256% 3.575%CO 805 586 219 4,990,326 523,417 4,466,909 0.994% 0.512% 2.283% 0.337% 0.528% 0.315%CT 654 617 37 2,589,153 261,886 2,327,267 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DE 247 244 3 647,226 365,826 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,317 1,295 22 16,794,353 14,552,348 2,242,005 0.380% 0.386% 0.000% 15.506% 17.895% 0.000%GA 294 280 14 974,583 282,561 692,022 0.340% 0.000% 7.143% 0.274% 0.000% 0.386%HI 112 100 12 1,305,882 1,251,254 54,628 0.893% 1.000% 0.000% 0.107% 0.112% 0.000%IA 1,056 1,023 33 2,543,237 1,434,611 1,108,626 0.189% 0.098% 3.030% 2.157% 0.122% 4.789%ID 879 825 54 1,074,009 827,601 246,408 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,160 1,058 102 9,113,191 2,914,019 6,199,172 2.069% 0.000% 23.529% 4.876% 0.000% 7.168%IN 1,405 1,361 44 4,872,043 2,552,307 2,319,736 0.712% 0.073% 20.455% 11.888% 0.002% 24.965%KY 243 93 150 4,612,320 375,460 4,236,860 9.465% 0.000% 15.333% 14.736% 0.000% 16.042%MA 644 527 117 8,485,298 1,682,916 6,802,382 0.311% 0.190% 0.855% 0.799% 1.430% 0.643%MD 861 793 68 4,906,042 907,935 3,998,107 2.439% 1.135% 17.647% 74.354% 0.378% 91.154%ME 269 241 28 510,420 134,500 375,920 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,934 2,873 61 7,227,105 2,047,249 5,179,856 0.068% 0.000% 3.279% 0.322% 0.000% 0.449%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,474 1,397 77 3,282,439 1,701,108 1,581,331 0.204% 0.072% 2.597% 1.188% 0.015% 2.450%MT 813 753 60 753,259 360,590 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.973% 0.269% 12.409% 25.074% 1.553% 32.989%ND 206 179 27 555,446 250,221 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 762 751 11 1,455,834 679,354 776,480 0.525% 0.266% 18.182% 36.986% 3.705% 66.103%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 131 119 12 2,002,039 354,819 1,647,220 0.763% 0.840% 0.000% 0.029% 0.166% 0.000%NM 695 659 36 1,661,712 1,398,814 262,898 0.144% 0.152% 0.000% 0.006% 0.007% 0.000%NV 295 274 21 961,667 271,776 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,343 1,113 230 4,923,387 981,697 3,941,690 0.074% 0.000% 0.435% 0.393% 0.000% 0.491%OH 1,939 1,814 125 10,227,103 3,132,166 7,094,937 2.940% 0.496% 38.400% 25.566% 1.608% 36.142%OKOR 1,084 934 150 2,937,354 572,604 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 105 97 8 902,560 163,122 739,438 2.857% 2.062% 12.500% 7.714% 0.835% 9.232%SC 770 711 59 3,427,270 800,487 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 86 25 61 1,856,148 161,124 1,695,024 2.326% 4.000% 1.639% 2.213% 0.053% 2.418%TX 2,002 1,665 337 21,523,196 5,759,696 15,763,500 1.149% 0.240% 5.638% 31.658% 0.653% 42.986%UT 425 388 37 2,500,321 1,667,135 833,186 0.235% 0.258% 0.000% 0.001% 0.001% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 442 409 33 432,954 181,790 251,164 0.452% 0.244% 3.030% 0.092% 0.169% 0.036%WI 1,413 1,393 20 3,884,401 2,192,657 1,691,744 0.425% 0.431% 0.000% 0.569% 1.008% 0.000%WV 342 196 146 1,366,817 206,226 1,160,591 3.216% 4.082% 2.055% 0.819% 0.828% 0.818%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 36,830 33,478 3,352 196,986,505 73,412,761 123,573,744 0.725% 0.221% 5.758% 10.641% 3.869% 14.665%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A55c. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 7 2 5 0.870% 0.341% 2.283% 16,129 2,066 14,063 0.323% 0.395% 0.315%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.340% 0.000% 7.143% 2,671 0 2,671 0.274% 0.000% 0.386%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 2 0 2 0.172% 0.000% 1.961% 7,529 0 7,529 0.083% 0.000% 0.121%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 2 0 2 0.823% 0.000% 1.333% 3,409 0 3,409 0.074% 0.000% 0.080%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.068% 0.072% 0.000% 250 250 0 0.008% 0.015% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 0 1 0.042% 0.000% 0.730% 72,480 0 72,480 1.053% 0.000% 1.407%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 1 1 0 0.144% 0.152% 0.000% 92 92 0 0.006% 0.007% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 1 0 1 0.052% 0.000% 0.800% 20,599 0 20,599 0.201% 0.000% 0.290%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 16 4 12 0.043% 0.012% 0.358% 123,159 2,408 120,751 0.063% 0.003% 0.098%

Percent of Population Served 

with At Least One Detection 

> 4 μg/L

State

Number of Systems 

with At Least One Detection 

> 4 μg/L

Percent of Systems 

with At Least One Detection 

> 4 μg/L

Population Served by Systems 

with At Least One Detection 

> 4 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A55d. Simazine – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 8 0 8 0.332% 0.000% 2.111% 487,920 0 487,920 1.398% 0.000% 2.225%CO 8 3 5 0.994% 0.512% 2.283% 16,829 2,766 14,063 0.337% 0.528% 0.315%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 0 1 0.340% 0.000% 7.143% 2,671 0 2,671 0.274% 0.000% 0.386%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 5 0 5 0.431% 0.000% 4.902% 29,291 0 29,291 0.321% 0.000% 0.472%IN 1 0 1 0.071% 0.000% 2.273% 1,350 0 1,350 0.028% 0.000% 0.058%KY 3 0 3 1.235% 0.000% 2.000% 53,630 0 53,630 1.163% 0.000% 1.266%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 1 0 1 0.116% 0.000% 1.471% 8,453 0 8,453 0.172% 0.000% 0.211%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 1 1 0 0.068% 0.072% 0.000% 250 250 0 0.008% 0.015% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 0 1 0.042% 0.000% 0.730% 72,480 0 72,480 1.053% 0.000% 1.407%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 1 1 0 0.144% 0.152% 0.000% 92 92 0 0.006% 0.007% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 4 0 4 0.206% 0.000% 3.200% 56,064 0 56,064 0.548% 0.000% 0.790%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 34 5 29 0.092% 0.015% 0.865% 729,030 3,108 725,922 0.370% 0.004% 0.587%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A56. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 100 μg/L 46,165 4 0.009% 86,392,838 1,310 0.002%

	
 46,165 7 0.015% 86,392,838 1,651 0.002%

> 100 μg/L 4,256 0 0.000% 140,540,798 0 0.000%

	
 4,256 0 0.000% 140,540,798 0 0.000%

> 100 μg/L 50,421 4 0.008% 226,933,636 1,310 0.001%

	
 50,421 7 0.014% 226,933,636 1,651 0.001%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A56a. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,116 1,977 1,139 0.289% 0.152% 0.527% 0.2 0.2 0.23 0.54 0.27 0.875 1.98 0.54 1.98 1.98 0.54 1.98AL 821 597 224 0.244% 0.335% 0.000% 0.53 0.53 5.215 5.215 9.9 9.9 9.9 9.9AR 2,393 1,926 467 0.125% 0.156% 0.000% 0.14 0.14 0.15 0.15 0.64 0.64 0.64 0.64AZ 11,698 9,531 2,167 0.060% 0.042% 0.138% 0.5 0.6 0.5 0.6 0.65 0.5 0.7 0.7 0.5 0.7 0.7 0.5CA 85,452 45,203 40,249 0.037% 0.040% 0.035% 0.5 0.6 0.5 0.88 1.15 0.75 5.6 6 5.6 7.7 7.7 5.6CO 2,864 2,125 739 0.908% 1.176% 0.135% 0.04 0.04 0.3 0.9 0.9 0.3 2 2 0.3 3.9 3.9 0.3CT 6,938 6,047 891 0.043% 0.050% 0.000% 0.5 0.5 1.2 1.2 1.8 1.8 1.8 1.8DE 1,048 1,018 30 0.382% 0.393% 0.000% 0.95 0.95 1.285 1.285 2.76 2.76 2.76 2.76FL 4,146 4,078 68 0.362% 0.368% 0.000% 0.08 0.08 0.22 0.22 0.34 0.34 0.5 0.5GA 7,175 6,348 827 0.014% 0.016% 0.000% 0.85 0.85 0.85 0.85 0.85 0.85 0.85 0.85HI 1,789 1,686 103 0.000% 0.000% 0.000%IA 1,788 1,662 126 0.951% 0.963% 0.794% 0.3 0.3 0.9 1.4 8.2 0.9 31 31 0.9 33 33 0.9ID 3,741 3,280 461 0.080% 0.091% 0.000% 0.5 0.5 6.4 6.4 500 500 500 500IL 7,012 6,452 560 0.157% 0.170% 0.000% 0.5 0.5 0.6 0.6 13.2 13.2 710 710IN 4,623 4,313 310 1.363% 1.461% 0.000% 0.5 0.5 2 2 8.7 8.7 24 24KY 3,306 1,123 2,183 0.514% 0.000% 0.779% 0.002 0.002 0.2 0.2 0.5 0.5 1 1MA 16,249 12,259 3,990 0.062% 0.082% 0.000% 0.5 0.5 0.665 0.665 4.25 4.25 7.4 7.4MD 6,770 5,510 1,260 0.369% 0.454% 0.000% 0.5 0.5 0.5 0.5 9.4 9.4 21.6 21.6ME 3,689 3,374 315 0.434% 0.474% 0.000% 0.5 0.5 2.6 2.6 14 14 18.9 18.9MI 10,753 9,743 1,010 0.335% 0.349% 0.198% 0.5 0.5 0.6 0.8 0.8 1.05 3 3 1.5 10.7 10.7 1.5MN 8,593 7,339 1,254 1.082% 1.022% 1.435% 0.5 0.5 0.5 2.2 2.5 0.95 20 21 3.5 96 96 9MO 7,543 6,694 849 0.013% 0.015% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5MT 4,490 3,951 539 0.000% 0.000% 0.000%NC 19,061 17,483 1,578 0.310% 0.326% 0.127% 0.5 0.5 0.68 1.3 1.3 1.64 8.18 8.18 2.6 66.1 66.1 2.6ND 552 417 135 0.906% 0.719% 1.481% 0.54 0.58 0.54 0.58 0.66 0.56 1.86 1.86 0.58 1.86 1.86 0.58NE 6,838 6,262 576 0.000% 0.000% 0.000%NH 9,583 9,105 478 0.083% 0.088% 0.000% 0.5 0.5 1.4 1.4 10 10 10 10NJ 20,347 18,561 1,786 0.147% 0.162% 0.000% 0.2 0.2 0.79 0.79 10.835 10.835 235 235NM 6,573 6,097 476 0.015% 0.016% 0.000% 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3NV 3,207 2,575 632 0.094% 0.078% 0.158% 0.2 0.2 0.55 0.55 1.25 0.55 2.3 2.3 0.55 2.3 2.3 0.55NY 7,097 5,427 1,670 0.127% 0.111% 0.180% 0.5 0.5 0.5 0.5 0.55 0.5 9 9 1.3 9 9 1.3OH 8,856 7,695 1,161 0.576% 0.650% 0.086% 0.55 0.55 1.1 1.63 1.635 1.1 9.87 10.935 1.1 108 108 1.1OK 5,356 3,959 1,397 0.504% 0.505% 0.501% 0.4 0.4 0.5 0.98 1.165 0.6 11.4 6.81 18.8 18.8 11.4 18.8OR 2,324 1,682 642 0.000% 0.000% 0.000%RI 1,959 1,591 368 0.051% 0.000% 0.272% 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7SC 4,207 3,725 482 0.024% 0.027% 0.000% 0.73 0.73 0.73 0.73 0.73 0.73 0.73 0.73SD 889 855 34 0.225% 0.234% 0.000% 0.24 0.24 0.425 0.425 0.61 0.61 0.61 0.61TN 2,936 1,163 1,773 0.034% 0.000% 0.056% 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2TX 34,145 27,041 7,104 0.082% 0.085% 0.070% 0.5 0.5 0.5 0.6 0.6 0.6 2.1 2.1 1.2 59 59 1.2UT 8,970 7,549 1,421 0.045% 0.053% 0.000% 0.9 0.9 1.15 1.15 1.8 1.8 1.8 1.8VA 4,930 4,058 872 1.075% 1.207% 0.459% 0.5 0.5 0.6 0.9 0.9 1.05 1.8 1.8 2 4.3 4.3 2VT 4,349 3,955 394 0.092% 0.101% 0.000% 0.6 0.6 0.75 0.75 0.97 0.97 0.97 0.97WI 11,294 11,169 125 0.832% 0.842% 0.000% 0.02 0.02 0.57 0.57 5.2 5.2 44 44WV 1,140 444 696 1.228% 2.477% 0.431% 0.11 0.11 0.5 0.5 0.5 0.5 0.5 0.5 1 1 0.5 1WY 1,659 1,156 503 0.060% 0.087% 0.000% 0.76 0.76 0.76 0.76 0.76 0.76 0.76 0.76Total 372,269 288,205 84,064 0.212% 0.242% 0.109% 0.002 0.02 0.002 0.885 0.9 0.69 7.5 8.1 2.6 710 710 18.8

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A56b. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.968% 0.422% 2.740% 1.634% 0.071% 2.607%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.760% 0.990% 0.000% 0.286% 1.073% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.661% 0.785% 0.000% 0.073% 0.196% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.378% 0.297% 2.083% 5.287% 0.932% 8.901%CA 3,643 3,127 516 35,826,547 13,514,486 22,312,061 0.549% 0.384% 1.550% 3.714% 3.175% 4.041%CO 826 605 221 4,997,841 530,207 4,467,634 2.785% 3.636% 0.452% 1.189% 1.463% 1.157%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.249% 0.257% 0.000% 0.018% 0.129% 0.000%DE 318 315 3 698,987 417,587 281,400 0.314% 0.317% 0.000% 0.030% 0.050% 0.000%FL 1,511 1,485 26 17,499,068 15,253,026 2,246,042 0.794% 0.808% 0.000% 1.003% 1.151% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.055% 0.059% 0.000% 0.001% 0.005% 0.000%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.852% 0.782% 3.030% 0.329% 0.314% 0.348%ID 935 878 57 1,093,666 837,604 256,062 0.321% 0.342% 0.000% 0.014% 0.018% 0.000%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 0.630% 0.679% 0.000% 0.188% 0.575% 0.000%IN 1,473 1,429 44 4,891,163 2,571,427 2,319,736 1.969% 2.029% 0.000% 0.502% 0.954% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 4.564% 0.000% 7.383% 10.587% 0.000% 11.527%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.975% 1.167% 0.000% 0.034% 0.166% 0.000%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 1.328% 1.420% 0.000% 0.493% 2.417% 0.000%ME 810 757 53 728,347 292,773 435,574 0.741% 0.793% 0.000% 0.160% 0.399% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 1.009% 0.962% 3.279% 0.705% 0.950% 0.611%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 3.161% 2.448% 40.000% 20.831% 6.020% 56.515%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.071% 0.075% 0.000% 0.043% 0.077% 0.000%MT 848 788 60 757,949 365,280 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 1.817% 1.840% 1.439% 1.424% 2.355% 1.118%ND 210 183 27 562,397 257,172 305,225 2.381% 1.639% 7.407% 0.891% 0.407% 1.299%NE 771 760 11 1,462,181 685,701 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 0.477% 0.493% 0.000% 2.096% 4.983% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 1.288% 1.323% 0.000% 0.048% 0.138% 0.000%NM 727 688 39 1,698,980 1,432,432 266,548 0.138% 0.145% 0.000% 0.012% 0.015% 0.000%NV 338 317 21 973,592 283,701 689,891 0.888% 0.631% 4.762% 35.542% 4.110% 48.467%NY 1,524 1,288 236 4,893,449 1,042,847 3,850,602 0.525% 0.388% 1.271% 0.107% 0.424% 0.021%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 1.492% 1.539% 0.800% 0.096% 0.220% 0.041%OK 718 506 212 3,119,686 660,832 2,458,854 3.621% 3.755% 3.302% 2.712% 9.542% 0.877%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 145 136 9 913,884 173,906 739,978 0.690% 0.000% 11.111% 5.553% 0.000% 6.858%SC 819 757 62 3,356,831 732,879 2,623,952 0.122% 0.132% 0.000% 0.001% 0.006% 0.000%SD 245 233 12 266,416 194,218 72,198 0.816% 0.858% 0.000% 0.077% 0.106% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.285% 0.000% 0.529% 0.026% 0.000% 0.035%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.444% 0.456% 0.292% 5.163% 13.847% 0.058%UT 500 454 46 2,553,197 1,698,877 854,320 0.600% 0.661% 0.000% 4.168% 6.264% 0.000%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 2.500% 2.589% 1.754% 1.356% 2.261% 1.233%VT 603 560 43 491,035 227,067 263,968 0.663% 0.714% 0.000% 0.063% 0.135% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 3.139% 3.175% 0.000% 3.254% 5.599% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.193% 1.018% 2.430%WY 304 256 48 446,177 129,229 316,948 0.329% 0.391% 0.000% 0.016% 0.056% 0.000%Total 50,421 46,165 4,256 226,933,636 86,392,838 140,540,798 1.047% 1.003% 1.527% 2.506% 3.038% 2.179%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A56c. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 1 1 0 0.107% 0.114% 0.000% 60 60 0 0.005% 0.007% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 200 200 0 0.002% 0.007% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 1 1 0 0.072% 0.073% 0.000% 400 400 0 0.005% 0.015% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 1 1 0 0.051% 0.055% 0.000% 650 650 0 0.006% 0.021% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 4 4 0 0.008% 0.009% 0.000% 1,310 1,310 0 0.001% 0.002% 0.000%

Percent of Population Served 

with At Least One Detection 

> 100 μg/L

State

Number of Systems 

with At Least One Detection 

> 100 μg/L

Percent of Systems 

with At Least One Detection 

> 100 μg/L

Population Served by Systems 

with At Least One Detection 

> 100 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A56d. Styrene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 1 1 0 0.107% 0.114% 0.000% 60 60 0 0.005% 0.007% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 200 200 0 0.002% 0.007% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 25 25 0 0.001% 0.001% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 40 40 0 0.001% 0.002% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 1 1 0 0.072% 0.073% 0.000% 400 400 0 0.005% 0.015% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 1 1 0 0.051% 0.055% 0.000% 650 650 0 0.006% 0.021% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 1 1 0 0.020% 0.022% 0.000% 276 276 0 0.001% 0.003% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 7 7 0 0.014% 0.015% 0.000% 1,651 1,651 0 0.001% 0.002% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A57. 2,3,7,8-TCDD (Dioxin) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration or 

Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.00003 μg/L 1,956 1 0.051% 16,399,032 7,100 0.043%

	
 1,956 2 0.102% 16,399,032 7,226 0.044%

> 0.00003 μg/L 427 0 0.000% 36,455,413 0 0.000%

	
 427 1 0.234% 36,455,413 2,400 0.007%

> 0.00003 μg/L 2,383 1 0.042% 52,854,445 7,100 0.013%

	
 2,383 3 0.126% 52,854,445 9,626 0.018%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A57a. 2,3,7,8-TCDD (Dioxin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 23 12 11 0.000% 0.000% 0.000%AL 1 0 1 100.000% 0.000% 100.000% 0.00003 0.00003 0.00003 0.00003 0.00003 0.00003 0.00003 0.00003ARAZ 3,059 2,073 986 0.425% 0.241% 0.811% 1E-06 3E-06 1E-06 4E-06 5E-06 3.5E-06 5E-06 0.00001 5E-06 0.00001 0.00001 5E-06CA 5,187 2,558 2,629 0.058% 0.078% 0.038% 3E-06 0.00001 3E-06 0.00001 9.4E-05 3E-06 0.00018 0.00018 3E-06 0.00018 0.00018 3E-06CO 58 48 10 0.000% 0.000% 0.000%CT 3 3 0 0.000% 0.000% 0.000%DEFL 187 146 41 0.000% 0.000% 0.000%GA 5 5 0 0.000% 0.000% 0.000%HIIAID 2 2 0 50.000% 50.000% 0.000% 5E-06 5E-06 5E-06 5E-06 5E-06 5E-06 5E-06 5E-06ILIN 170 55 115 0.000% 0.000% 0.000%KY 77 5 72 0.000% 0.000% 0.000%MA 1 0 1 0.000% 0.000% 0.000%MD 83 4 79 0.000% 0.000% 0.000%MEMIMNMOMT 922 832 90 0.000% 0.000% 0.000%NC 26 7 19 0.000% 0.000% 0.000%ND 2 1 1 0.000% 0.000% 0.000%NE 11 11 0 0.000% 0.000% 0.000%NHNJNM 4 2 2 0.000% 0.000% 0.000%NV 958 553 405 0.104% 0.181% 0.000% 2.5E-05 2.5E-05 2.5E-05 2.5E-05 2.5E-05 2.5E-05 2.5E-05 2.5E-05NY 79 12 67 0.000% 0.000% 0.000%OH 39 21 18 0.000% 0.000% 0.000%OKOR 5 2 3 0.000% 0.000% 0.000%RISCSDTN 10 2 8 0.000% 0.000% 0.000%TXUT 15 8 7 0.000% 0.000% 0.000%VAVT 10 9 1 0.000% 0.000% 0.000%WI 128 69 59 0.781% 1.449% 0.000% 2E-06 2E-06 2E-06 2E-06 2E-06 2E-06 2E-06 2E-06WVWY 11 5 6 0.000% 0.000% 0.000%Total 11,076 6,445 4,631 0.181% 0.155% 0.216% 1E-06 2E-06 1E-06 5E-06 5E-06 3.5E-06 2.8E-05 0.0001 1.8E-05 0.00018 0.00018 0.00003

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A57b. 2,3,7,8-TCDD (Dioxin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 6 5 1 19,333 13,461 5,872 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 1 0 1 2,400 0 2,400 100.000% 0.000% 100.000% 100.000% 0.000% 100.000%ARAZ 598 552 46 5,381,098 2,011,562 3,369,536 1.672% 0.725% 13.043% 5.280% 1.338% 7.634%CA 595 431 164 24,075,352 7,031,578 17,043,774 0.504% 0.464% 0.610% 0.085% 0.101% 0.078%CO 35 27 8 1,936,985 61,912 1,875,073 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 2 2 0 520 520 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%DEFL 104 88 16 7,701,758 5,634,110 2,067,648 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%GA 4 4 0 27,571 27,571 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIAID 2 2 0 1,254 1,254 0 50.000% 50.000% 0.000% 20.175% 20.175% 0.000%ILIN 86 43 43 2,343,633 26,697 2,316,936 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 29 5 24 2,094,576 27,456 2,067,120 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MA 1 0 1 37,615 0 37,615 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MD 7 3 4 1,824,735 68 1,824,667 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MEMIMNMOMT 605 557 48 685,741 309,762 375,979 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 12 7 5 837,285 69,714 767,571 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ND 2 1 1 13,483 11,700 1,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 6 6 0 12,822 12,822 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NHNJNM 3 2 1 3,897 3,347 550 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 146 127 19 806,913 126,427 680,486 0.685% 0.787% 0.000% 0.016% 0.100% 0.000%NY 17 8 9 506,453 18,987 487,466 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OH 20 12 8 1,086,855 69,630 1,017,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 3 1 2 67,955 75 67,880 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RISCSDTN 5 2 3 1,167,103 721,882 445,221 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TXUT 6 4 2 188,815 31,155 157,660 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VAVT 10 9 1 76,237 7,314 68,923 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WI 71 54 17 1,821,983 179,333 1,642,650 1.408% 1.852% 0.000% 0.007% 0.075% 0.000%WVWY 7 4 3 132,073 695 131,378 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 2,383 1,956 427 52,854,445 16,399,032 36,455,413 0.713% 0.460% 1.874% 0.582% 0.211% 0.749%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A57c. 2,3,7,8-TCDD (Dioxin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

 Table A57c. 2,3,7,8-TCDD (Dioxin) – Summary of Stage 1 (Peak) Analyses of Any Detections > 0.00003 μg/L (Single detections > 0.00003 μg/L are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ARAZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.168% 0.232% 0.000% 7,100 7,100 0 0.029% 0.101% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DEFL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIAID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ILIN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MEMIMNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJNM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RISCSDTN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VAVT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WVWY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 1 0 0.042% 0.051% 0.000% 7,100 7,100 0 0.013% 0.043% 0.000%

Percent of Population Served 

with At Least One Detection 

> 0.00003 μg/L State

Number of Systems 

with At Least One Detection 

> 0.00003 μg/L

Percent of Systems 

with At Least One Detection 

> 0.00003 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.00003 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A57d. 2,3,7,8-TCDD (Dioxin – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

 Table A57d. 2,3,7,8-TCDD (Dioxin) – Summary of Stage 1 (Peak) Analyses of Any Detections 	
	
!!"
#

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 0 1 100.000% 0.000% 100.000% 2,400 0 2,400 100.000% 0.000% 100.000%ARAZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.168% 0.232% 0.000% 7,100 7,100 0 0.029% 0.101% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DEFL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIAID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ILIN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MEMIMNMOMT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NHNJNM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 1 0 0.685% 0.787% 0.000% 126 126 0 0.016% 0.100% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RISCSDTN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TXUT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VAVT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WVWY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 3 2 1 0.126% 0.102% 0.234% 9,626 7,226 2,400 0.018% 0.044% 0.007%

Percent of Population Served 

with At Least One Detection 

	
 State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A58. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 46,180 185 0.401% 86,396,173 3,823,729 4.426%

	
 46,180 331 0.717% 86,396,173 6,157,866 7.127%

	
 46,180 615 1.332% 86,396,173 10,479,911 12.130%

> 0.5 μg/L 46,180 915 1.981% 86,396,173 12,472,505 14.436%

> 5 μg/L 4,256 56 1.316% 140,612,382 10,814,217 7.691%

	
 4,256 73 1.715% 140,612,382 11,524,206 8.196%

	
 4,256 118 2.773% 140,612,382 15,318,905 10.894%

> 0.5 μg/L 4,256 148 3.477% 140,612,382 17,083,237 12.149%

> 5 μg/L 50,436 241 0.478% 227,008,555 14,637,946 6.448%

	
 50,436 404 0.801% 227,008,555 17,682,072 7.789%

	
 50,436 733 1.453% 227,008,555 25,798,816 11.365%

> 0.5 μg/L 50,436 1,063 2.108% 227,008,555 29,555,742 13.020%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A58a. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,128 1,977 1,151 0.863% 0.556% 1.390% 0.29 0.29 0.3 0.95 0.76 1.11 4.04 3.3 4.04 9.54 5 9.54AL 1,092 736 356 30.769% 22.962% 46.910% 0.5 0.5 0.5 1.7 1.54 1.82 6.18 4.8 9.3 43.1 15.5 43.1AR 2,393 1,926 467 1.421% 1.765% 0.000% 0.19 0.19 0.55 0.55 1.09 1.09 1.84 1.84AZ 12,720 9,662 3,058 2.956% 3.353% 1.700% 0.5 0.5 0.5 1.2 1.3 0.79 10 11 1.5 17 17 2.1CA 117,322 62,663 54,659 21.784% 21.979% 21.559% 0.05 0.05 0.49 2 2.2 1.7 9.5 7.4 14 177 177 88CO 2,895 2,155 740 1.244% 1.578% 0.270% 0.33 0.33 1 1.3 1.3 1 2.1 2.1 1 2.6 2.6 1CT 6,983 6,073 910 5.385% 4.034% 14.396% 0.08 0.08 0.6 1.5 1 2.8 13.3 7.1 28 47.1 47.1 42DE 1,050 1,020 30 1.048% 0.882% 6.667% 0.68 0.68 1.65 1.42 1.36 3.955 6.26 14.6 6.26 14.6 14.6 6.26FL 4,152 4,084 68 7.948% 8.080% 0.000% 0.03 0.03 0.52 0.52 1.405 1.405 5.1 5.1GA 7,174 6,347 827 1.101% 1.197% 0.363% 0.5 0.5 0.5 0.72 0.735 0.52 2.3 2.3 0.64 3.1 3.1 0.64HI 1,789 1,686 103 0.000% 0.000% 0.000%IA 1,923 1,796 127 4.420% 4.621% 1.575% 0.5 0.5 0.6 1.9 1.9 1.75 4.6 4.6 2.9 16.19 16.19 2.9ID 3,794 3,329 465 4.692% 4.266% 7.742% 0.3 0.3 0.5 0.8 0.8 1.35 3.4 1.8 6.3 9.6 9.6 8.5IL 7,054 6,485 569 2.566% 2.791% 0.000% 0.5 0.5 1.12 1.12 3.68 3.68 6.4 6.4IN 4,625 4,315 310 1.016% 1.089% 0.000% 0.5 0.5 2.2 2.2 6.8 6.8 47 47KY 3,315 1,130 2,185 0.814% 1.416% 0.503% 0.001 0.4 0.001 0.6 0.65 0.5 7 2 7 23 23 23MA 19,988 15,236 4,752 14.599% 15.522% 11.637% 0.2 0.2 0.5 1 1 1 2.9 2.4 5 34 34 25MD 6,776 5,514 1,262 3.143% 3.845% 0.079% 0.4 0.4 0.9 1.9 1.9 0.9 5.1 5.1 0.9 45 45 0.9ME 3,689 3,374 315 0.623% 0.622% 0.635% 0.5 0.5 1.4 0.9 0.88 1.5 1.9 1.9 1.6 17 17 1.6MI 10,752 9,742 1,010 1.479% 1.632% 0.000% 0.4 0.4 0.9 0.9 3.1 3.1 10.8 10.8MN 8,592 7,342 1,250 1.734% 1.920% 0.640% 0.2 0.2 0.2 0.5 0.5 0.3 2.2 2.2 0.8 16 16 0.8MO 7,543 6,694 849 2.174% 2.435% 0.118% 0.51 0.51 3.6 1.67 1.67 3.6 3.3 3.2 3.6 14.3 14.3 3.6MT 4,496 3,957 539 0.601% 0.607% 0.557% 0.36 0.36 0.61 0.79 0.775 0.8 2.3 1.7 2.9 2.9 2.31 2.9NC 19,066 17,487 1,579 1.295% 1.407% 0.063% 0.5 0.5 0.9 1.1 1.1 0.9 2.5 2.5 0.9 9.52 9.52 0.9ND 558 417 141 2.867% 1.679% 6.383% 0.57 0.57 1.03 2 1.08 3.89 6.2 1.7 8.16 8.16 1.7 8.16NE 6,837 6,261 576 1.858% 2.028% 0.000% 0.27 0.27 1.31 1.31 7.1 7.1 13 13NH 9,587 9,109 478 0.970% 1.010% 0.209% 0.28 0.28 2.6 1.1 1.1 2.6 11 11 2.6 45 45 2.6NJ 20,347 18,562 1,785 3.313% 3.356% 2.857% 0.1 0.13 0.1 0.6 0.6 0.5 1.53 1.6 0.72 141.5 141.5 2.1NM 6,574 6,098 476 2.784% 2.870% 1.681% 0.1 0.1 0.26 1.3 1.2 8.45 4.88 4.56 16.7 45.01 45.01 16.7NV 3,270 2,586 684 5.719% 0.889% 23.977% 0.2 0.5 0.2 8.5 1.05 9.815 18.4 5.9 19 33.1 9.3 33.1NY 7,094 5,426 1,668 3.496% 1.788% 9.053% 0.5 0.5 0.5 5.1 8.2 3.2 24.2 32 16.5 38 38 25.8OH 8,850 7,689 1,161 2.508% 2.874% 0.086% 0.5 0.5 1.36 1.1 1.1 1.36 2.56 2.56 1.36 14.16 14.16 1.36OK 5,634 4,199 1,435 0.728% 0.953% 0.070% 0.4 0.4 1.8 0.7 0.7 1.8 4.5 5.75 1.8 23 23 1.8OR 2,334 1,691 643 2.614% 3.548% 0.156% 0.53 0.53 1.3 2 2 1.3 5.4 5.6 1.3 8.43 8.43 1.3RI 1,959 1,591 368 2.450% 2.577% 1.902% 0.5 0.5 0.5 0.9 0.9 0.7 2 2 0.9 2.5 2.5 0.9SC 4,344 3,805 539 2.187% 2.392% 0.742% 0.3 0.3 0.69 1.19 1.19 1.555 4.87 4.87 2.66 12.7 12.7 2.66SD 889 855 34 1.800% 1.871% 0.000% 0.5 0.5 0.695 0.695 1.68 1.68 2.29 2.29TN 2,939 1,165 1,774 2.416% 1.459% 3.044% 0.54 0.6 0.54 0.9 0.8 0.9 2 2.2 2 17 2.5 17TX 34,158 27,054 7,104 0.632% 0.780% 0.070% 0.5 0.5 0.6 0.8 0.8 0.7 2.5 2.5 6.1 13 13 6.1UT 8,989 7,561 1,428 0.667% 0.661% 0.700% 0.6 0.7 0.6 3.65 6.65 1.3 21.6 21.6 3.75 21.6 21.6 3.9VA 4,893 4,025 868 1.655% 1.988% 0.115% 0.5 0.5 2.8 1.6 1.6 2.8 7 7.05 2.8 24 24 2.8VT 4,343 3,952 391 2.763% 3.036% 0.000% 0.23 0.23 0.95 0.95 4.45 4.45 9 9WI 11,299 11,174 125 5.638% 5.611% 8.000% 0.01 0.01 0.22 0.99 1 0.455 3.3 3.3 0.92 16 16 0.95WV 1,173 472 701 2.046% 4.025% 0.713% 0.1 0.1 0.3 0.5 0.5 0.5 1 1.3 1 1.37 1.37 1WY 1,660 1,157 503 0.723% 0.778% 0.596% 0.56 0.56 0.6 1 1 1.2 2 2.01 1.9 2.01 2.01 1.9Total 410,042 309,579 100,463 8.490% 6.961% 13.200% 0.001 0.01 0.001 1.6 1.6 1.6 8.5 6.5 14 177 177 88

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A58b. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.968% 0.844% 1.370% 36.994% 0.853% 59.494%AL 264 202 62 4,231,003 1,123,190 3,107,813 9.091% 7.921% 12.903% 20.375% 23.612% 19.205%AR 454 382 72 2,453,348 910,322 1,543,026 1.542% 1.832% 0.000% 1.403% 3.780% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 2.833% 2.671% 6.250% 29.125% 31.867% 26.850%CA 3,657 3,141 516 35,889,084 13,517,016 22,372,068 6.043% 5.126% 11.628% 43.506% 32.570% 50.112%CO 826 605 221 4,997,841 530,207 4,467,634 1.695% 1.983% 0.905% 1.416% 12.977% 0.044%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 4.225% 3.853% 15.385% 11.989% 14.457% 11.577%DE 319 316 3 699,787 418,387 281,400 2.194% 1.899% 33.333% 7.728% 4.291% 12.839%FL 1,509 1,483 26 17,495,514 15,249,472 2,246,042 0.729% 0.742% 0.000% 3.878% 4.450% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.823% 0.821% 0.862% 0.774% 0.696% 0.795%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 1.705% 1.564% 6.061% 11.839% 13.903% 9.168%ID 935 878 57 1,093,666 837,604 256,062 2.781% 2.506% 7.018% 25.094% 9.938% 74.670%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 1.610% 1.736% 0.000% 3.374% 10.309% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 1.357% 1.399% 0.000% 5.387% 10.246% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 6.224% 5.435% 6.711% 9.113% 3.644% 9.599%MA 718 600 118 8,557,325 1,749,901 6,807,424 12.953% 12.000% 17.797% 14.611% 44.536% 6.918%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 2.941% 3.043% 1.471% 6.629% 32.102% 0.096%ME 810 757 53 728,347 292,773 435,574 1.111% 0.925% 3.774% 1.333% 1.459% 1.249%MI 2,973 2,912 61 7,158,313 1,978,457 5,179,856 1.043% 1.065% 0.000% 1.116% 4.039% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 2.718% 2.384% 20.000% 9.550% 12.596% 2.212%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.847% 0.821% 1.299% 0.929% 1.505% 0.187%MT 848 788 60 757,949 365,280 392,669 1.179% 1.015% 3.333% 15.683% 21.455% 10.315%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 2.535% 2.648% 0.719% 1.266% 4.930% 0.060%ND 210 183 27 562,397 257,172 305,225 1.905% 1.639% 3.704% 2.342% 2.467% 2.236%NE 771 760 11 1,462,181 685,701 776,480 2.464% 2.500% 0.000% 9.203% 19.624% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 2.305% 2.301% 2.439% 7.856% 11.664% 5.093%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 7.654% 7.421% 16.216% 29.098% 30.068% 28.576%NM 727 688 39 1,698,980 1,432,432 266,548 3.576% 3.488% 5.128% 41.846% 49.062% 3.064%NV 338 317 21 973,592 283,701 689,891 2.959% 2.208% 14.286% 36.481% 6.842% 48.670%NY 1,522 1,286 236 4,894,720 1,044,118 3,850,602 1.445% 1.477% 1.271% 6.635% 5.125% 7.045%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 1.492% 1.539% 0.800% 1.296% 4.023% 0.092%OK 730 518 212 3,123,687 664,833 2,458,854 1.233% 1.544% 0.472% 2.594% 8.858% 0.901%OR 1,097 945 152 2,940,119 574,689 2,365,430 1.550% 1.693% 0.658% 1.851% 8.688% 0.190%RI 145 136 9 913,884 173,906 739,978 4.138% 3.676% 11.111% 12.189% 4.301% 14.043%SC 819 757 62 3,356,831 732,879 2,623,952 2.808% 2.906% 1.613% 1.190% 4.039% 0.394%SD 245 233 12 266,416 194,218 72,198 1.633% 1.717% 0.000% 7.503% 10.293% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 2.564% 2.469% 2.646% 3.794% 6.451% 2.873%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.727% 0.716% 0.877% 9.994% 17.309% 5.694%UT 500 454 46 2,553,197 1,698,877 854,320 1.800% 1.762% 2.174% 20.974% 13.157% 36.520%VA 1,589 1,419 170 5,269,764 628,329 4,641,435 1.259% 1.339% 0.588% 0.141% 1.177% 0.001%VT 603 560 43 491,035 227,067 263,968 2.819% 3.036% 0.000% 1.220% 2.639% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 3.643% 3.571% 10.000% 17.882% 28.502% 3.142%WV 403 243 160 1,416,020 237,670 1,178,350 4.963% 6.584% 2.500% 3.186% 6.878% 2.441%WY 304 256 48 446,177 129,229 316,948 1.316% 1.172% 2.083% 0.203% 0.391% 0.126%Total 50,436 46,180 4,256 227,008,555 86,396,173 140,612,382 2.502% 2.362% 4.018% 14.076% 15.923% 12.940%

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting Percent of Systems with At Least One Detection Total Population Served by Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A58c. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 0 1 0.161% 0.000% 0.685% 60 0 60 0.010% 0.000% 0.016%AL 8 3 5 3.030% 1.485% 8.065% 563,685 31,322 532,363 13.323% 2.789% 17.130%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 6 6 0 0.567% 0.593% 0.000% 53,295 53,295 0 0.864% 1.906% 0.000%CA 88 58 30 2.406% 1.847% 5.814% 11,244,688 2,364,769 8,879,919 31.332% 17.495% 39.692%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 15 12 3 1.243% 1.027% 7.692% 160,099 9,872 150,227 5.879% 2.535% 6.437%DE 2 1 1 0.627% 0.316% 33.333% 45,331 9,201 36,130 6.478% 2.199% 12.839%FL 1 1 0 0.066% 0.067% 0.000% 315,516 315,516 0 1.803% 2.069% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 3 3 0 0.284% 0.293% 0.000% 2,330 2,330 0 0.092% 0.162% 0.000%ID 3 2 1 0.321% 0.228% 1.754% 196,565 10,565 186,000 17.973% 1.261% 72.639%IL 3 3 0 0.210% 0.226% 0.000% 39,517 39,517 0 0.429% 1.310% 0.000%IN 3 3 0 0.204% 0.210% 0.000% 15,270 15,270 0 0.312% 0.594% 0.000%KY 3 1 2 1.245% 1.087% 1.342% 195 100 95 0.004% 0.027% 0.002%MA 20 13 7 2.786% 2.167% 5.932% 439,709 222,107 217,602 5.138% 12.693% 3.197%MD 6 6 0 0.569% 0.609% 0.000% 25,570 25,570 0 0.509% 2.494% 0.000%ME 1 1 0 0.123% 0.132% 0.000% 155 155 0 0.021% 0.053% 0.000%MI 2 2 0 0.067% 0.069% 0.000% 3,145 3,145 0 0.044% 0.159% 0.000%MN 4 4 0 0.253% 0.258% 0.000% 50,911 50,911 0 1.195% 1.691% 0.000%MO 1 1 0 0.071% 0.075% 0.000% 500 500 0 0.017% 0.030% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 3 0 0.127% 0.135% 0.000% 1,610 1,610 0 0.023% 0.093% 0.000%ND 1 0 1 0.476% 0.000% 3.704% 6,826 0 6,826 1.214% 0.000% 2.236%NE 8 8 0 1.038% 1.053% 0.000% 61,022 61,022 0 4.173% 8.899% 0.000%NH 6 6 0 0.477% 0.493% 0.000% 2,280 2,280 0 0.240% 0.571% 0.000%NJ 10 10 0 0.715% 0.735% 0.000% 223,585 223,585 0 2.886% 8.243% 0.000%NM 3 2 1 0.413% 0.291% 2.564% 93,085 84,948 8,137 5.479% 5.930% 3.053%NV 3 2 1 0.888% 0.631% 4.762% 352,410 18,040 334,370 36.197% 6.359% 48.467%NY 5 4 1 0.329% 0.311% 0.424% 294,555 23,605 270,950 6.018% 2.261% 7.037%OH 2 2 0 0.103% 0.110% 0.000% 185 185 0 0.002% 0.006% 0.000%OK 2 2 0 0.274% 0.386% 0.000% 41,408 41,408 0 1.326% 6.228% 0.000%OR 4 4 0 0.365% 0.423% 0.000% 17,110 17,110 0 0.582% 2.977% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 4 4 0 0.488% 0.528% 0.000% 5,800 5,800 0 0.173% 0.791% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 0 1 0.285% 0.000% 0.529% 6,597 0 6,597 0.116% 0.000% 0.156%TX 3 2 1 0.061% 0.043% 0.292% 185,225 284 184,941 0.738% 0.003% 1.169%UT 5 5 0 1.000% 1.101% 0.000% 105,470 105,470 0 4.131% 6.208% 0.000%VA 3 3 0 0.189% 0.211% 0.000% 598 598 0 0.011% 0.095% 0.000%VT 3 3 0 0.498% 0.536% 0.000% 1,453 1,453 0 0.296% 0.640% 0.000%WI 5 5 0 0.280% 0.283% 0.000% 82,186 82,186 0 2.035% 3.501% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 241 185 56 0.478% 0.401% 1.316% 14,637,946 3,823,729 10,814,217 6.448% 4.426% 7.691%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A58d. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 3 2 1 0.484% 0.422% 0.685% 600 540 60 0.099% 0.232% 0.016%AL 10 5 5 3.788% 2.475% 8.065% 614,286 81,923 532,363 14.519% 7.294% 17.130%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 10 10 0 0.944% 0.989% 0.000% 54,081 54,081 0 0.877% 1.934% 0.000%CA 113 79 34 3.090% 2.515% 6.589% 12,172,668 3,078,916 9,093,752 33.917% 22.778% 40.648%CO 1 1 0 0.121% 0.165% 0.000% 175 175 0 0.004% 0.033% 0.000%CT 23 19 4 1.906% 1.627% 10.256% 178,184 25,450 152,734 6.543% 6.535% 6.544%DE 2 1 1 0.627% 0.316% 33.333% 45,331 9,201 36,130 6.478% 2.199% 12.839%FL 3 3 0 0.199% 0.202% 0.000% 346,855 346,855 0 1.983% 2.275% 0.000%GA 2 2 0 0.110% 0.117% 0.000% 7,176 7,176 0 0.096% 0.451% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 7 6 1 0.663% 0.587% 3.030% 21,527 4,913 16,614 0.846% 0.342% 1.499%ID 4 2 2 0.428% 0.228% 3.509% 196,730 10,565 186,165 17.988% 1.261% 72.703%IL 10 10 0 0.700% 0.755% 0.000% 263,476 263,476 0 2.858% 8.733% 0.000%IN 7 7 0 0.475% 0.490% 0.000% 20,126 20,126 0 0.411% 0.783% 0.000%KY 3 1 2 1.245% 1.087% 1.342% 195 100 95 0.004% 0.027% 0.002%MA 41 30 11 5.710% 5.000% 9.322% 761,818 458,661 303,157 8.903% 26.211% 4.453%MD 11 11 0 1.044% 1.116% 0.000% 276,396 276,396 0 5.502% 26.958% 0.000%ME 1 1 0 0.123% 0.132% 0.000% 155 155 0 0.021% 0.053% 0.000%MI 7 7 0 0.235% 0.240% 0.000% 11,590 11,590 0 0.162% 0.586% 0.000%MN 6 6 0 0.379% 0.387% 0.000% 53,074 53,074 0 1.246% 1.763% 0.000%MO 5 4 1 0.353% 0.299% 1.299% 7,834 5,371 2,463 0.261% 0.318% 0.187%MT 1 0 1 0.118% 0.000% 1.667% 38,477 0 38,477 5.076% 0.000% 9.799%NC 11 11 0 0.465% 0.494% 0.000% 12,093 12,093 0 0.173% 0.698% 0.000%ND 1 0 1 0.476% 0.000% 3.704% 6,826 0 6,826 1.214% 0.000% 2.236%NE 13 13 0 1.686% 1.711% 0.000% 124,220 124,220 0 8.496% 18.116% 0.000%NH 9 8 1 0.715% 0.657% 2.439% 30,444 2,444 28,000 3.209% 0.613% 5.093%NJ 18 18 0 1.288% 1.323% 0.000% 279,330 279,330 0 3.605% 10.298% 0.000%NM 4 3 1 0.550% 0.436% 2.564% 93,120 84,983 8,137 5.481% 5.933% 3.053%NV 3 2 1 0.888% 0.631% 4.762% 352,410 18,040 334,370 36.197% 6.359% 48.467%NY 7 6 1 0.460% 0.467% 0.424% 294,635 23,685 270,950 6.019% 2.268% 7.037%OH 8 8 0 0.412% 0.440% 0.000% 6,857 6,857 0 0.067% 0.219% 0.000%OK 2 2 0 0.274% 0.386% 0.000% 41,408 41,408 0 1.326% 6.228% 0.000%OR 7 7 0 0.638% 0.741% 0.000% 48,240 48,240 0 1.641% 8.394% 0.000%RI 1 1 0 0.690% 0.735% 0.000% 60 60 0 0.007% 0.035% 0.000%SC 5 4 1 0.611% 0.528% 1.613% 16,150 5,800 10,350 0.481% 0.791% 0.394%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 2 1 1 0.570% 0.617% 0.529% 11,891 5,294 6,597 0.209% 0.362% 0.156%TX 10 9 1 0.202% 0.195% 0.292% 486,437 301,496 184,941 1.937% 3.243% 1.169%UT 6 5 1 1.200% 1.101% 2.174% 417,470 105,470 312,000 16.351% 6.208% 36.520%VA 7 6 1 0.441% 0.423% 0.588% 1,285 1,260 25 0.024% 0.201% 0.001%VT 5 5 0 0.829% 0.893% 0.000% 2,425 2,425 0 0.494% 1.068% 0.000%WI 15 15 0 0.841% 0.850% 0.000% 386,017 386,017 0 9.556% 16.442% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 404 331 73 0.801% 0.717% 1.715% 17,682,072 6,157,866 11,524,206 7.789% 7.127% 8.196%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A58e. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 4 2 2 0.645% 0.422% 1.370% 222,811 540 222,271 36.756% 0.232% 59.494%AL 16 11 5 6.061% 5.446% 8.065% 748,146 215,783 532,363 17.682% 19.212% 17.130%AR 1 1 0 0.220% 0.262% 0.000% 19,465 19,465 0 0.793% 2.138% 0.000%AZ 18 16 2 1.700% 1.583% 4.167% 1,366,960 761,960 605,000 22.166% 27.249% 17.949%CA 171 120 51 4.676% 3.820% 9.884% 14,825,825 3,871,181 10,954,644 41.310% 28.639% 48.966%CO 5 3 2 0.605% 0.496% 0.905% 42,236 40,256 1,980 0.845% 7.593% 0.044%CT 33 28 5 2.734% 2.397% 12.821% 273,620 43,684 229,936 10.047% 11.217% 9.852%DE 6 5 1 1.881% 1.582% 33.333% 53,281 17,151 36,130 7.614% 4.099% 12.839%FL 5 5 0 0.331% 0.337% 0.000% 547,143 547,143 0 3.127% 3.588% 0.000%GA 4 4 0 0.220% 0.234% 0.000% 8,127 8,127 0 0.109% 0.510% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 12 11 1 1.136% 1.075% 3.030% 98,355 81,741 16,614 3.867% 5.698% 1.499%ID 16 13 3 1.711% 1.481% 5.263% 263,947 75,897 188,050 24.134% 9.061% 73.439%IL 15 15 0 1.050% 1.132% 0.000% 265,484 265,484 0 2.880% 8.800% 0.000%IN 13 13 0 0.882% 0.909% 0.000% 144,949 144,949 0 2.963% 5.637% 0.000%KY 5 2 3 2.075% 2.174% 2.013% 49,095 200 48,895 1.067% 0.053% 1.157%MA 69 53 16 9.610% 8.833% 13.559% 1,091,310 697,472 393,838 12.753% 39.858% 5.785%MD 23 23 0 2.182% 2.333% 0.000% 327,996 327,996 0 6.529% 31.990% 0.000%ME 4 2 2 0.494% 0.264% 3.774% 5,630 190 5,440 0.773% 0.065% 1.249%MI 14 14 0 0.471% 0.481% 0.000% 66,157 66,157 0 0.924% 3.344% 0.000%MN 11 11 0 0.695% 0.709% 0.000% 110,145 110,145 0 2.585% 3.658% 0.000%MO 8 7 1 0.565% 0.522% 1.299% 17,361 14,898 2,463 0.578% 0.882% 0.187%MT 5 4 1 0.590% 0.508% 1.667% 38,917 440 38,477 5.135% 0.120% 9.799%NC 31 31 0 1.310% 1.391% 0.000% 58,871 58,871 0 0.841% 3.397% 0.000%ND 4 3 1 1.905% 1.639% 3.704% 13,170 6,344 6,826 2.342% 2.467% 2.236%NE 14 14 0 1.816% 1.842% 0.000% 125,114 125,114 0 8.557% 18.246% 0.000%NH 11 10 1 0.874% 0.822% 2.439% 30,574 2,574 28,000 3.222% 0.645% 5.093%NJ 38 36 2 2.718% 2.645% 5.405% 1,035,707 332,953 702,754 13.367% 12.275% 13.955%NM 7 6 1 0.963% 0.872% 2.564% 198,570 190,433 8,137 11.688% 13.294% 3.053%NV 7 5 2 2.071% 1.577% 9.524% 353,680 18,910 334,770 36.327% 6.665% 48.525%NY 11 10 1 0.723% 0.778% 0.424% 298,846 27,896 270,950 6.105% 2.672% 7.037%OH 22 21 1 1.132% 1.154% 0.800% 74,168 67,619 6,549 0.725% 2.159% 0.092%OK 4 3 1 0.548% 0.579% 0.472% 63,642 41,489 22,153 2.037% 6.241% 0.901%OR 10 9 1 0.912% 0.952% 0.658% 53,178 48,678 4,500 1.809% 8.470% 0.190%RI 4 4 0 2.759% 2.941% 0.000% 4,838 4,838 0 0.529% 2.782% 0.000%SC 16 15 1 1.954% 1.982% 1.613% 34,996 24,646 10,350 1.043% 3.363% 0.394%SD 1 1 0 0.408% 0.429% 0.000% 99 99 0 0.037% 0.051% 0.000%TN 7 2 5 1.994% 1.235% 2.646% 128,955 7,619 121,336 2.268% 0.521% 2.873%TX 23 21 2 0.465% 0.456% 0.585% 1,776,182 1,563,928 212,254 7.073% 16.822% 1.342%UT 9 8 1 1.800% 1.762% 2.174% 535,520 223,520 312,000 20.974% 13.157% 36.520%VA 13 12 1 0.818% 0.846% 0.588% 3,966 3,941 25 0.075% 0.627% 0.001%VT 11 11 0 1.824% 1.964% 0.000% 4,059 4,059 0 0.827% 1.788% 0.000%WI 24 24 0 1.345% 1.361% 0.000% 406,853 406,853 0 10.072% 17.329% 0.000%WV 4 3 1 0.993% 1.235% 0.625% 9,963 8,163 1,800 0.704% 3.435% 0.153%WY 4 3 1 1.316% 1.172% 2.083% 905 505 400 0.203% 0.391% 0.126%Total 733 615 118 1.453% 1.332% 2.773% 25,798,816 10,479,911 15,318,905 11.365% 12.130% 10.894%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A58f. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 4 2 2 0.645% 0.422% 1.370% 222,811 540 222,271 36.756% 0.232% 59.494%AL 24 16 8 9.091% 7.921% 12.903% 862,055 265,205 596,850 20.375% 23.612% 19.205%AR 3 3 0 0.661% 0.785% 0.000% 24,460 24,460 0 0.997% 2.687% 0.000%AZ 25 23 2 2.361% 2.275% 4.167% 1,487,387 882,387 605,000 24.119% 31.556% 17.949%CA 219 159 60 5.989% 5.062% 11.628% 15,548,678 4,337,492 11,211,186 43.324% 32.089% 50.112%CO 11 9 2 1.332% 1.488% 0.905% 69,582 67,602 1,980 1.392% 12.750% 0.044%CT 50 44 6 4.143% 3.767% 15.385% 326,356 56,164 270,192 11.984% 14.421% 11.577%DE 7 6 1 2.194% 1.899% 33.333% 54,081 17,951 36,130 7.728% 4.291% 12.839%FL 5 5 0 0.331% 0.337% 0.000% 547,143 547,143 0 3.127% 3.588% 0.000%GA 13 12 1 0.714% 0.703% 0.862% 57,672 10,811 46,861 0.770% 0.679% 0.795%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 18 16 2 1.705% 1.564% 6.061% 301,076 199,434 101,642 11.839% 13.903% 9.168%ID 23 20 3 2.460% 2.278% 5.263% 268,828 80,778 188,050 24.580% 9.644% 73.439%IL 23 23 0 1.610% 1.736% 0.000% 311,020 311,020 0 3.374% 10.309% 0.000%IN 18 18 0 1.221% 1.259% 0.000% 204,818 204,818 0 4.187% 7.965% 0.000%KY 9 5 4 3.734% 5.435% 2.685% 88,762 13,679 75,083 1.929% 3.644% 1.776%MA 89 69 20 12.396% 11.500% 16.949% 1,232,504 778,651 453,853 14.403% 44.497% 6.667%MD 30 29 1 2.846% 2.941% 1.471% 332,919 329,079 3,840 6.627% 32.096% 0.096%ME 6 4 2 0.741% 0.528% 3.774% 8,795 3,355 5,440 1.208% 1.146% 1.249%MI 20 20 0 0.673% 0.687% 0.000% 76,588 76,588 0 1.070% 3.871% 0.000%MN 18 17 1 1.138% 1.095% 3.333% 225,783 211,700 14,083 5.299% 7.031% 1.127%MO 12 11 1 0.847% 0.821% 1.299% 27,896 25,433 2,463 0.929% 1.505% 0.187%MT 10 8 2 1.179% 1.015% 3.333% 118,871 78,369 40,502 15.683% 21.455% 10.315%NC 55 54 1 2.324% 2.424% 0.719% 78,110 74,961 3,149 1.116% 4.326% 0.060%ND 4 3 1 1.905% 1.639% 3.704% 13,170 6,344 6,826 2.342% 2.467% 2.236%NE 16 16 0 2.075% 2.105% 0.000% 125,364 125,364 0 8.574% 18.283% 0.000%NH 27 26 1 2.146% 2.136% 2.439% 74,254 46,254 28,000 7.826% 11.593% 5.093%NJ 73 69 4 5.222% 5.070% 10.811% 1,735,338 698,387 1,036,951 22.396% 25.747% 20.591%NM 10 9 1 1.376% 1.308% 2.564% 199,447 191,310 8,137 11.739% 13.356% 3.053%NV 9 6 3 2.663% 1.893% 14.286% 354,880 19,110 335,770 36.451% 6.736% 48.670%NY 15 14 1 0.986% 1.089% 0.424% 319,962 49,012 270,950 6.537% 4.694% 7.037%OH 29 28 1 1.492% 1.539% 0.800% 132,561 126,012 6,549 1.296% 4.023% 0.092%OK 6 5 1 0.822% 0.965% 0.472% 70,071 47,918 22,153 2.243% 7.208% 0.901%OR 17 16 1 1.550% 1.693% 0.658% 54,427 49,927 4,500 1.851% 8.688% 0.190%RI 6 5 1 4.138% 3.676% 11.111% 111,396 7,480 103,916 12.189% 4.301% 14.043%SC 22 21 1 2.686% 2.774% 1.613% 38,464 28,114 10,350 1.146% 3.836% 0.394%SD 3 3 0 1.224% 1.288% 0.000% 14,490 14,490 0 5.439% 7.461% 0.000%TN 9 4 5 2.564% 2.469% 2.646% 215,680 94,344 121,336 3.794% 6.451% 2.873%TX 33 30 3 0.667% 0.651% 0.877% 2,507,699 1,607,200 900,499 9.986% 17.287% 5.694%UT 9 8 1 1.800% 1.762% 2.174% 535,520 223,520 312,000 20.974% 13.157% 36.520%VA 20 19 1 1.259% 1.339% 0.588% 7,422 7,397 25 0.141% 1.177% 0.001%VT 16 16 0 2.653% 2.857% 0.000% 5,949 5,949 0 1.212% 2.620% 0.000%WI 38 37 1 2.130% 2.098% 5.000% 548,008 513,508 34,500 13.566% 21.872% 2.039%WV 5 4 1 1.241% 1.646% 0.625% 14,540 12,740 1,800 1.027% 5.360% 0.153%WY 4 3 1 1.316% 1.172% 2.083% 905 505 400 0.203% 0.391% 0.126%Total 1,063 915 148 2.108% 1.981% 3.477% 29,555,742 12,472,505 17,083,237 13.020% 14.436% 12.149%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A59. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 0.002 mg/L 44,898 101 0.225% 85,832,905 281,729 0.328%

	
 44,898 703 1.566% 85,832,905 5,653,247 6.586%> 0.002 mg/L 4,027 24 0.596% 137,491,940 1,550,072 1.127%

	
 4,027 154 3.824% 137,491,940 14,008,014 10.188%

> 0.002 mg/L 48,925 125 0.255% 223,324,845 1,831,801 0.820%	
 48,925 857 1.752% 223,324,845 19,661,261 8.804%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A59a. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 1,498 1,062 436 4.539% 4.614% 4.358% 6.1E-05 6.1E-05 0.00016 0.001 0.001 0.001 0.00162 0.00162 0.0017 0.00246 0.00246 0.002AL 2,639 1,795 844 0.379% 0.501% 0.118% 0.001 0.001 0.00209 0.005 0.005 0.00209 0.0085 0.01 0.00209 0.01 0.01 0.00209AR 2,214 1,550 664 0.407% 0.323% 0.602% 0.0005 0.0006 0.0005 0.0006 0.0006 0.00055 0.001 0.001 0.0007 0.001 0.001 0.0007AZ 6,273 5,002 1,271 1.084% 1.060% 1.180% 0.0007 0.0007 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.01 0.003 0.01CA 34,960 20,908 14,052 0.503% 0.550% 0.434% 3.3E-05 4.7E-05 3.3E-05 0.001 0.001 0.001 0.0023 0.0025 0.00218 0.01 0.01 0.01CO 4,373 2,334 2,039 2.424% 2.828% 1.962% 0.00006 0.0001 0.00006 0.00058 0.0006 0.00048 0.0018 0.002 0.00165 0.005 0.005 0.0033CT 2,231 1,841 390 0.941% 1.086% 0.256% 0.0001 0.0005 0.0001 0.0012 0.00135 0.0001 0.002 0.0021 0.0001 0.005 0.005 0.0001DE 686 639 47 1.603% 1.721% 0.000% 0.0001 0.0001 0.0002 0.0002 0.001 0.001 0.002 0.002FL 2,143 2,074 69 5.880% 6.027% 1.449% 0.0001 0.0001 0.0001 0.0005 0.0005 0.0001 0.0014 0.0014 0.0001 0.006 0.006 0.0001GA 2,691 2,368 323 0.149% 0.169% 0.000% 0.0011 0.0011 0.00135 0.00135 0.0015 0.0015 0.0015 0.0015HI 1,176 1,114 62 0.000% 0.000% 0.000%IA 1,482 1,219 263 0.000% 0.000% 0.000%ID 3,080 2,798 282 0.877% 0.858% 1.064% 0.00003 0.00003 0.0001 0.0007 0.00085 0.0002 0.0017 0.0017 0.0006 0.0055 0.0055 0.0006IL 2,762 2,362 400 0.615% 0.677% 0.250% 5.1E-05 5.1E-05 0.0012 0.0012 0.0013 0.0012 0.002 0.002 0.0012 0.0025 0.0025 0.0012IN 4,724 4,243 481 0.910% 0.919% 0.832% 0.00018 0.00018 0.0005 0.001 0.0014 0.0009 0.003 0.003 0.001 0.0088 0.0088 0.001KY 1,809 554 1,255 6.302% 2.347% 8.048% 0.0001 0.0001 0.0001 0.00095 0.0009 0.001 0.0019 0.002 0.0018 0.01 0.002 0.01MA 2,990 2,006 984 1.906% 2.343% 1.016% 0.0002 0.0002 0.0003 0.001 0.001 0.001 0.002 0.002 0.00185 0.0033 0.0033 0.002MD 5,064 3,961 1,103 0.533% 0.429% 0.907% 0.00003 0.0002 0.00003 0.001 0.0011 0.001 0.003 0.004 0.00212 0.004 0.004 0.00223ME 2,341 1,956 385 0.128% 0.051% 0.519% 0.001 0.001 0.001 0.001 0.001 0.0015 0.002 0.001 0.002 0.002 0.001 0.002MI 6,722 6,543 179 3.139% 3.179% 1.676% 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.0003 0.0003 0.0001 0.01 0.01 0.0001MN 4,437 4,358 79 0.518% 0.505% 1.266% 0.001 0.001 0.001 0.0012 0.0012 0.001 0.0016 0.0016 0.001 0.0023 0.0023 0.001MO 5,706 4,929 777 0.105% 0.122% 0.000% 0.00104 0.00104 0.00137 0.00137 0.00165 0.00165 0.00165 0.00165MT 3,169 2,829 340 0.032% 0.000% 0.294% 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002NC 9,271 7,828 1,443 1.402% 1.405% 1.386% 0.00009 0.00009 0.0006 0.001 0.001 0.001 0.00225 0.0024 0.002 0.09 0.09 0.003ND 345 303 42 0.000% 0.000% 0.000%NE 2,976 2,867 109 0.101% 0.105% 0.000% 0.0001 0.0001 0.0001 0.0001 0.001 0.001 0.001 0.001NH 2,928 2,764 164 0.376% 0.398% 0.000% 0.00007 0.00007 0.001 0.001 0.01 0.01 0.01 0.01NJ 6,591 5,867 724 0.804% 0.835% 0.552% 0.0001 0.0001 0.0007 0.002 0.002 0.0015 0.005 0.005 0.005 0.01 0.01 0.005NM 3,520 3,194 326 26.932% 27.771% 18.712% 0.00003 0.00003 0.00003 0.0001 0.0001 0.0001 0.00051 0.00047 0.00078 0.01 0.01 0.00351NV 2,109 1,536 573 0.901% 0.781% 1.222% 0.0001 0.0001 0.001 0.0011 0.001 0.002 0.0065 0.0028 0.0072 0.0072 0.0065 0.0072NY 3,296 2,497 799 1.608% 1.482% 2.003% 0.00004 0.00004 0.00059 0.001 0.001 0.0013 0.003 0.002 0.005 0.01 0.01 0.009OH 4,648 4,011 637 0.409% 0.374% 0.628% 0.0006 0.00064 0.0006 0.00145 0.0015 0.0007 0.0017 0.0017 0.0007 0.00181 0.00181 0.0007OK 396 333 63 0.505% 0.300% 1.587% 0.0026 0.0026 0.01 0.0063 0.0026 0.01 0.01 0.0026 0.01 0.01 0.0026 0.01OR 1,311 951 360 0.076% 0.000% 0.278% 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002RI 860 630 230 0.233% 0.000% 0.870% 0.0008 0.0008 0.0009 0.0009 0.001 0.001 0.001 0.001SC 3,446 2,982 464 0.784% 0.704% 1.293% 0.001 0.001 0.001 0.002 0.002 0.002 0.003 0.003 0.003 0.01 0.01 0.003SD 412 383 29 0.000% 0.000% 0.000%TN 1,838 644 1,194 6.910% 0.311% 10.469% 0.0007 0.0007 0.0009 0.0011 0.00115 0.0011 0.0017 0.0016 0.0017 0.002 0.0016 0.002TX 14,759 12,179 2,580 0.285% 0.296% 0.233% 0.0004 0.0004 0.00049 0.00118 0.00118 0.00118 0.00276 0.0036 0.00234 0.02 0.02 0.00234UT 6,998 5,459 1,539 3.844% 4.158% 2.729% 0.0002 0.0003 0.0002 0.0011 0.0011 0.001 0.002 0.002 0.0047 0.01 0.01 0.01VA 2,800 2,192 608 0.286% 0.319% 0.164% 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002 0.002VT 2,107 1,763 344 0.285% 0.340% 0.000% 0.001 0.001 0.001 0.001 0.002 0.002 0.002 0.002WI 7,038 6,867 171 3.055% 3.087% 1.754% 0.00003 0.00003 0.0002 0.0006 0.0006 0.00041 0.0017 0.0017 0.0007 0.01 0.01 0.0007WV 1,105 421 684 2.353% 3.563% 1.608% 0.00012 0.00012 0.00012 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001WY 1,123 874 249 0.623% 0.572% 0.803% 0.0004 0.0004 0.0012 0.0012 0.002 0.0012 0.01 0.01 0.0012 0.01 0.01 0.0012Total 185,047 144,990 40,057 1.673% 1.728% 1.473% 0.00003 0.00003 0.00003 0.00067 0.00046 0.001 0.002 0.002 0.002 0.09 0.09 0.01

Median Detect 

Concentration (mg/L)

Maximum Detect 

Concentration (mg/L)

90th Percentile Detect 

Concentration (mg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (mg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A59b. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 610 467 143 592,922 230,950 361,972 9.672% 9.850% 9.091% 42.961% 8.329% 65.058%AL 352 279 73 4,701,100 1,463,066 3,238,034 1.420% 1.434% 1.370% 1.213% 2.015% 0.850%AR 453 381 72 2,452,800 909,774 1,543,026 1.325% 1.312% 1.389% 0.815% 0.597% 0.944%AZ 1,051 1,003 48 6,159,082 2,788,491 3,370,591 4.662% 4.088% 16.667% 16.807% 8.162% 23.958%CA 3,744 3,227 517 36,250,792 13,502,653 22,748,139 2.751% 2.262% 5.803% 13.420% 10.810% 14.970%CO 838 617 221 4,998,506 533,275 4,465,231 7.041% 5.835% 10.407% 6.727% 12.090% 6.087%CT 1,170 1,131 39 2,716,176 382,254 2,333,922 1.795% 1.768% 2.564% 2.280% 0.850% 2.515%DE 281 278 3 679,823 398,423 281,400 3.203% 3.237% 0.000% 5.163% 8.809% 0.000%FL 1,333 1,307 26 17,371,132 15,125,090 2,246,042 6.302% 6.350% 3.846% 30.071% 32.629% 12.848%GA 1,586 1,472 114 7,238,277 1,345,946 5,892,331 0.252% 0.272% 0.000% 0.227% 1.223% 0.000%HI 107 95 12 1,303,767 1,249,139 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 963 930 33 2,495,648 1,387,022 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 923 874 49 1,078,374 833,464 244,910 2.384% 2.288% 4.082% 12.405% 14.262% 6.083%IL 1,240 1,139 101 9,078,598 2,879,370 6,199,228 1.210% 1.229% 0.990% 1.291% 2.780% 0.600%IN 1,622 1,573 49 4,980,032 2,619,577 2,360,455 2.404% 2.352% 4.082% 9.806% 7.919% 11.901%KY 242 93 149 4,602,489 375,460 4,227,029 25.620% 10.753% 34.899% 25.309% 5.643% 27.055%MA 676 558 118 8,525,575 1,718,151 6,807,424 5.473% 5.735% 4.237% 44.069% 4.237% 54.123%MD 1,038 970 68 5,022,488 1,024,381 3,998,107 2.119% 1.753% 7.353% 36.598% 0.335% 45.890%ME 802 748 54 727,134 291,530 435,604 0.374% 0.134% 3.704% 1.747% 0.055% 2.880%MI 3,033 2,980 53 6,717,830 1,925,399 4,792,431 6.100% 6.107% 5.660% 6.871% 7.894% 6.461%MN 1,593 1,564 29 4,265,162 3,015,521 1,249,641 1.067% 1.023% 3.448% 13.510% 3.667% 37.262%MO 1,420 1,343 77 3,006,718 1,692,257 1,314,461 0.352% 0.372% 0.000% 0.553% 0.982% 0.000%MT 849 789 60 757,930 365,261 392,669 0.118% 0.000% 1.667% 0.011% 0.000% 0.022%NC 2,284 2,145 139 6,973,609 1,708,443 5,265,166 4.991% 4.569% 11.511% 14.929% 11.242% 16.125%ND 217 190 27 563,069 257,844 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 743 732 11 1,450,223 673,743 776,480 0.269% 0.273% 0.000% 0.076% 0.163% 0.000%NH 1,216 1,175 41 942,517 392,718 549,799 0.740% 0.766% 0.000% 0.196% 0.470% 0.000%NJ 1,374 1,337 37 7,762,423 2,726,477 5,035,946 3.130% 2.917% 10.811% 9.266% 8.505% 9.679%NM 725 686 39 1,668,123 1,401,575 266,548 42.759% 43.440% 30.769% 42.808% 40.152% 56.774%NV 334 313 21 973,017 283,126 689,891 2.994% 2.875% 4.762% 6.911% 3.794% 8.190%NY 1,552 1,316 236 4,383,193 1,213,289 3,169,904 3.028% 2.584% 5.508% 2.796% 5.962% 1.585%OH 1,933 1,808 125 10,225,465 3,130,528 7,094,937 0.776% 0.774% 0.800% 16.690% 1.621% 23.340%OK 184 168 16 680,015 269,060 410,955 1.087% 0.595% 6.250% 3.900% 1.507% 5.466%OR 730 609 121 2,770,014 486,768 2,283,246 0.137% 0.000% 0.826% 5.998% 0.000% 7.277%RI 143 134 9 913,584 173,606 739,978 1.399% 0.000% 22.222% 5.930% 0.000% 7.322%SC 823 758 65 3,468,333 809,806 2,658,527 2.552% 2.375% 4.615% 2.700% 1.426% 3.087%SD 234 223 11 339,259 247,298 91,961 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 1.140% 1.235% 1.058% 9.123% 3.109% 11.206%TX 4,888 4,547 341 25,060,220 9,275,719 15,784,501 0.675% 0.638% 1.173% 3.626% 0.945% 5.202%UT 507 457 50 2,543,652 1,686,017 857,635 14.990% 14.661% 18.000% 44.438% 33.023% 66.878%VA 1,582 1,414 168 4,803,450 634,384 4,169,066 0.379% 0.354% 0.595% 0.113% 0.456% 0.061%VT 601 558 43 490,989 227,021 263,968 0.832% 0.896% 0.000% 0.192% 0.415% 0.000%WI 1,823 1,803 20 4,044,416 2,352,672 1,691,744 9.490% 9.429% 15.000% 10.374% 16.081% 2.438%WV 451 290 161 1,415,477 234,687 1,180,790 4.878% 5.172% 4.348% 1.525% 1.053% 1.619%WY 304 255 49 446,184 129,168 317,016 2.303% 1.961% 4.082% 1.178% 0.701% 1.372%Total 48,925 44,898 4,027 223,324,845 85,832,905 137,491,940 3.493% 3.285% 5.811% 12.626% 11.410% 13.385%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A59c. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.164% 0.214% 0.000% 120 120 0 0.020% 0.052% 0.000%AL 4 3 1 1.136% 1.075% 1.370% 53,723 26,189 27,534 1.143% 1.790% 0.850%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 2 1 1 0.190% 0.100% 2.083% 125,301 801 124,500 2.034% 0.029% 3.694%CA 15 12 3 0.401% 0.372% 0.580% 663,501 12,953 650,548 1.830% 0.096% 2.860%CO 7 5 2 0.835% 0.810% 0.905% 6,597 2,297 4,300 0.132% 0.431% 0.096%CT 2 2 0 0.171% 0.177% 0.000% 225 225 0 0.008% 0.059% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 2 2 0 0.150% 0.153% 0.000% 11,069 11,069 0 0.064% 0.073% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 1 1 0 0.108% 0.114% 0.000% 46,500 46,500 0 4.312% 5.579% 0.000%IL 1 1 0 0.081% 0.088% 0.000% 170 170 0 0.002% 0.006% 0.000%IN 10 10 0 0.617% 0.636% 0.000% 3,518 3,518 0 0.071% 0.134% 0.000%KY 3 0 3 1.240% 0.000% 2.013% 126,627 0 126,627 2.751% 0.000% 2.996%MA 1 1 0 0.148% 0.179% 0.000% 200 200 0 0.002% 0.012% 0.000%MD 6 5 1 0.578% 0.515% 1.471% 90,811 279 90,532 1.808% 0.027% 2.264%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 1 1 0 0.033% 0.034% 0.000% 27 27 0 0.000% 0.001% 0.000%MN 1 1 0 0.063% 0.064% 0.000% 55,300 55,300 0 1.297% 1.834% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 12 11 1 0.525% 0.513% 0.719% 52,298 29,298 23,000 0.750% 1.715% 0.437%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 2 2 0 0.164% 0.170% 0.000% 283 283 0 0.030% 0.072% 0.000%NJ 7 6 1 0.509% 0.449% 2.703% 9,351 720 8,631 0.120% 0.026% 0.171%NM 7 6 1 0.966% 0.875% 2.564% 92,144 19,443 72,701 5.524% 1.387% 27.275%NV 3 2 1 0.898% 0.639% 4.762% 65,960 9,460 56,500 6.779% 3.341% 8.190%NY 6 3 3 0.387% 0.228% 1.271% 13,931 2,605 11,326 0.318% 0.215% 0.357%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 2 1 1 1.087% 0.595% 6.250% 26,519 4,056 22,463 3.900% 1.507% 5.466%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 5 4 1 0.608% 0.528% 1.538% 7,075 3,467 3,608 0.204% 0.428% 0.136%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 8 7 1 0.164% 0.154% 0.293% 46,891 39,687 7,204 0.187% 0.428% 0.046%UT 8 5 3 1.578% 1.094% 6.000% 331,964 11,366 320,598 13.051% 0.674% 37.382%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 6 6 0 0.329% 0.333% 0.000% 1,455 1,455 0 0.036% 0.062% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 2 2 0 0.658% 0.784% 0.000% 241 241 0 0.054% 0.187% 0.000%Total 125 101 24 0.255% 0.225% 0.596% 1,831,801 281,729 1,550,072 0.820% 0.328% 1.127%

Percent of Population Served 

with At Least One Detection 

> 0.002 mg/L

State

Number of Systems 

with At Least One Detection 

> 0.002 mg/L

Percent of Systems 

with At Least One Detection 

> 0.002 mg/L

Population Served by Systems 

with At Least One Detection 

> 0.002 mg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A59d. Thallium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 34 24 10 5.574% 5.139% 6.993% 239,006 6,812 232,194 40.310% 2.950% 64.147%AL 5 4 1 1.420% 1.434% 1.370% 57,014 29,480 27,534 1.213% 2.015% 0.850%AR 1 1 0 0.221% 0.262% 0.000% 1,834 1,834 0 0.075% 0.202% 0.000%AZ 48 40 8 4.567% 3.988% 16.667% 998,818 191,275 807,543 16.217% 6.859% 23.958%CA 86 63 23 2.297% 1.952% 4.449% 4,033,580 1,240,374 2,793,206 11.127% 9.186% 12.279%CO 27 17 10 3.222% 2.755% 4.525% 244,095 24,275 219,820 4.883% 4.552% 4.923%CT 19 19 0 1.624% 1.680% 0.000% 3,189 3,189 0 0.117% 0.834% 0.000%DE 3 3 0 1.068% 1.079% 0.000% 967 967 0 0.142% 0.243% 0.000%FL 27 27 0 2.026% 2.066% 0.000% 2,780,540 2,780,540 0 16.007% 18.384% 0.000%GA 4 4 0 0.252% 0.272% 0.000% 16,464 16,464 0 0.227% 1.223% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 10 10 0 1.083% 1.144% 0.000% 54,466 54,466 0 5.051% 6.535% 0.000%IL 14 13 1 1.129% 1.141% 0.990% 117,072 79,885 37,187 1.290% 2.774% 0.600%IN 32 31 1 1.973% 1.971% 2.041% 293,716 30,196 263,520 5.898% 1.153% 11.164%KY 37 5 32 15.289% 5.376% 21.477% 858,838 14,303 844,535 18.660% 3.809% 19.979%MA 34 30 4 5.030% 5.376% 3.390% 3,708,067 67,460 3,640,607 43.493% 3.926% 53.480%MD 17 15 2 1.638% 1.546% 2.941% 1,803,315 2,783 1,800,532 35.905% 0.272% 45.035%ME 3 1 2 0.374% 0.134% 3.704% 12,705 160 12,545 1.747% 0.055% 2.880%MI 3 3 0 0.099% 0.101% 0.000% 627 627 0 0.009% 0.033% 0.000%MN 17 16 1 1.067% 1.023% 3.448% 576,207 110,567 465,640 13.510% 3.667% 37.262%MO 5 5 0 0.352% 0.372% 0.000% 16,620 16,620 0 0.553% 0.982% 0.000%MT 1 0 1 0.118% 0.000% 1.667% 85 0 85 0.011% 0.000% 0.022%NC 108 94 14 4.729% 4.382% 10.072% 1,013,112 178,157 834,955 14.528% 10.428% 15.858%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 1 1 0 0.135% 0.137% 0.000% 43 43 0 0.003% 0.006% 0.000%NH 8 8 0 0.658% 0.681% 0.000% 1,736 1,736 0 0.184% 0.442% 0.000%NJ 37 34 3 2.693% 2.543% 8.108% 505,088 94,339 410,749 6.507% 3.460% 8.156%NM 30 28 2 4.138% 4.082% 5.128% 207,584 134,733 72,851 12.444% 9.613% 27.331%NV 6 5 1 1.796% 1.597% 4.762% 66,348 9,848 56,500 6.819% 3.478% 8.190%NY 31 19 12 1.997% 1.444% 5.085% 88,507 38,346 50,161 2.019% 3.161% 1.582%OH 11 11 0 0.569% 0.608% 0.000% 38,726 38,726 0 0.379% 1.237% 0.000%OK 2 1 1 1.087% 0.595% 6.250% 26,519 4,056 22,463 3.900% 1.507% 5.466%OR 1 0 1 0.137% 0.000% 0.826% 166,150 0 166,150 5.998% 0.000% 7.277%RI 1 0 1 0.699% 0.000% 11.111% 51,000 0 51,000 5.582% 0.000% 6.892%SC 21 18 3 2.552% 2.375% 4.615% 93,633 11,551 82,082 2.700% 1.426% 3.087%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 3 1 2 0.855% 0.617% 1.058% 513,986 40,773 473,213 9.041% 2.788% 11.206%TX 25 22 3 0.511% 0.484% 0.880% 200,419 67,521 132,898 0.800% 0.728% 0.842%UT 68 61 7 13.412% 13.348% 14.000% 821,427 330,244 491,183 32.293% 19.587% 57.272%VA 6 5 1 0.379% 0.354% 0.595% 5,432 2,894 2,538 0.113% 0.456% 0.061%VT 5 5 0 0.832% 0.896% 0.000% 942 942 0 0.192% 0.415% 0.000%WI 42 42 0 2.304% 2.329% 0.000% 24,205 24,205 0 0.598% 1.029% 0.000%WV 18 13 5 3.991% 4.483% 3.106% 14,193 2,221 11,972 1.003% 0.946% 1.014%WY 6 4 2 1.974% 1.569% 4.082% 4,986 635 4,351 1.117% 0.492% 1.372%Total 857 703 154 1.752% 1.566% 3.824% 19,661,261 5,653,247 14,008,014 8.804% 6.586% 10.188%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A60. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 1,000 μg/L 46,193 1 0.002% 86,403,546 500 0.001%

}	
 46,193 14 0.030% 86,403,546 15,689 0.018%	
 46,193 15 0.032% 86,403,546 15,757 0.018%

> 1,000 μg/L 4,258 0 0.000% 140,551,755 0 0.000%

}	
 4,258 1 0.023% 140,551,755 1,612 0.001%	
 4,258 3 0.070% 140,551,755 6,212 0.004%

> 1,000 μg/L 50,451 1 0.002% 226,955,301 500 0.000%

}	
 50,451 15 0.030% 226,955,301 17,301 0.008%	
 50,451 18 0.036% 226,955,301 21,969 0.010%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A60a. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,388 2,222 1,166 6.346% 4.500% 9.863% 0.1 0.1 0.12 0.57 0.695 0.49 2.87 3.845 2.25 100 43.6 100AL 846 614 232 4.019% 3.746% 4.741% 0.5 0.5 0.55 0.895 1 0.8 16 6.41 16 78 78 18AR 2,393 1,926 467 1.295% 1.506% 0.428% 0.09 0.09 0.14 0.62 0.67 0.22 7.46 10 0.3 296 296 0.3AZ 11,717 9,548 2,169 0.819% 0.880% 0.553% 0.4 0.4 0.5 0.9 0.99 0.6 6.4 6.7 2.5 24 24 3.1CA 86,373 45,816 40,557 0.315% 0.404% 0.215% 0.38 0.38 0.5 1 1.1 1 6.8 11 4.52 390 390 77CO 2,919 2,170 749 2.672% 2.995% 1.736% 0.13 0.13 0.2 0.735 0.64 1 2.8 3.2 2 830 830 2.3CT 6,945 6,054 891 1.094% 1.255% 0.000% 0.51 0.51 2.35 2.35 18.2 18.2 530 530DE 1,051 1,021 30 2.664% 2.742% 0.000% 0.6 0.6 1.35 1.35 35.9 35.9 80.1 80.1FL 4,160 4,089 71 0.962% 0.954% 1.408% 0.05 0.05 0.09 0.5 0.5 0.09 8.15 8.4 0.09 11 11 0.09GA 7,174 6,347 827 0.725% 0.788% 0.242% 0.5 0.5 0.96 1.1 1.1 1.08 4.1 4.25 1.2 18 18 1.2HI 1,791 1,688 103 0.000% 0.000% 0.000%IA 1,997 1,832 165 2.754% 2.183% 9.091% 0.5 0.5 0.5 1.2 1.3 1 4 4.105 3.2 22.6 22.6 4.6ID 3,742 3,281 461 1.015% 1.128% 0.217% 0.5 0.5 0.5 1.1 1.1 0.5 38 38 0.5 800 800 0.5IL 7,035 6,462 573 0.597% 0.650% 0.000% 0.12 0.12 0.8 0.8 2.4 2.4 19.8 19.8IN 4,623 4,313 310 2.963% 3.107% 0.968% 0.5 0.5 0.86 1.3 1.3 2.2 4.7 4.7 3.4 39 39 3.4KY 3,351 1,131 2,220 1.761% 0.973% 2.162% 0.002 0.3 0.002 0.7 0.9 0.7 2.4 19 2 40 40 18MA 16,249 12,259 3,990 0.677% 0.808% 0.276% 0.5 0.5 0.5 1.1 1.2 0.99 6.6 7 1.6 44 44 1.68MD 6,775 5,513 1,262 2.421% 2.721% 1.109% 0.1 0.2 0.1 1.45 1.6 0.65 8.9 8.95 1.5 24 24 2.1ME 3,693 3,374 319 1.679% 1.423% 4.389% 0.5 0.5 0.5 1.45 1.5 1.45 11.5 19.3 5.5 55 55 6.7MI 10,754 9,744 1,010 1.246% 1.293% 0.792% 0.08 0.08 0.5 0.8 0.8 1.2 4.6 4.9 3.4 5100 5100 3.4MN 8,596 7,343 1,253 2.873% 2.492% 5.108% 0.2 0.2 0.2 0.4 0.5 0.3 1.6 2.2 0.7 46 46 5.2MO 7,544 6,695 849 1.577% 1.449% 2.591% 0.5 0.5 0.5 1.01 1.1 0.9 7.5 11.3 1.8 149 149 4.8MT 4,496 3,955 541 0.489% 0.506% 0.370% 0.21 0.21 3.8 3.1 2.65 3.9 730 840 4 1000 1000 4NC 19,062 17,483 1,579 1.096% 1.161% 0.380% 0.5 0.5 0.5 1.2 1.2 0.675 5.6 5.6 1.8 170 170 1.8ND 564 429 135 2.482% 3.030% 0.741% 0.5 0.5 2.02 0.67 0.67 2.02 2.02 1.43 2.02 5.39 5.39 2.02NE 6,838 6,262 576 0.351% 0.383% 0.000% 0.14 0.14 0.735 0.735 1.8 1.8 3.6 3.6NH 9,614 9,136 478 2.517% 2.638% 0.209% 0.0077 0.0077 0.74 1.4 1.4 0.74 15 15 0.74 260 260 0.74NJ 20,359 18,571 1,788 1.483% 1.556% 0.727% 0.07 0.07 0.1 0.67 0.69 0.5 3 3.2 1.4 820 820 1.7NM 6,572 6,096 476 1.263% 1.312% 0.630% 0.1 0.1 0.77 0.69 0.6 1.3 5.26 5.3 2.4 180 180 2.4NV 3,219 2,580 639 1.336% 1.318% 1.408% 0.52 0.55 0.52 1.22 1.445 0.66 3.4 3.8 1.4 4.9 4.9 1.4NY 7,173 5,489 1,684 1.157% 1.221% 0.950% 0.12 0.5 0.12 1.3 1.3 1.15 12.4 12.4 500 800 800 567OH 8,845 7,685 1,160 1.119% 1.262% 0.172% 0.5 0.5 0.7 1.2 1.3 0.8 3.65 3.65 0.9 17 17 0.9OK 5,355 3,958 1,397 1.120% 1.061% 1.288% 0.1 0.1 0.43 0.8 0.765 0.94 3.6 3.9 3.3 45 45 4.62OR 2,336 1,693 643 0.728% 0.886% 0.311% 0.2 0.2 1 1.3 1.6 1 48 48 1 54.8 54.8 1RI 1,959 1,591 368 1.276% 1.257% 1.359% 0.2 0.2 0.5 1.4 1.8 0.63 25 30.5 4.8 110 110 4.8SC 4,345 3,805 540 1.220% 1.340% 0.370% 0.51 0.51 0.71 0.77 0.78 0.725 2.18 2.18 0.74 18.8 18.8 0.74SD 889 855 34 1.012% 1.053% 0.000% 0.51 0.51 0.65 0.65 37.2 37.2 37.2 37.2TN 2,943 1,165 1,778 0.102% 0.000% 0.169% 0.5 0.5 1.8 1.8 3.2 3.2 3.2 3.2TX 34,177 27,069 7,108 1.911% 2.050% 1.379% 0.5 0.5 0.5 1.1 1.3 0.8 5.3 5.5 3.3 200 200 33UT 8,980 7,559 1,421 0.445% 0.463% 0.352% 0.4 0.4 0.6 1.15 1.2 0.7 20.2 35.6 1.9 35.6 35.6 1.9VA 4,933 4,060 873 2.352% 2.537% 1.489% 0.5 0.5 0.5 1 1.1 0.7 5 5 2 63 63 5VT 4,358 3,964 394 2.685% 2.901% 0.508% 0.2 0.2 0.6 1 1.1 0.7 5.7 5.7 0.8 600 600 0.8WI 11,303 11,178 125 2.636% 2.657% 0.800% 0.02 0.02 0.84 0.54 0.54 0.84 3.2 3.2 0.84 57 57 0.84WV 1,150 449 701 2.261% 4.232% 0.999% 0.16 0.16 0.5 0.5 0.5 1 9 9 740 740 700 740WY 1,664 1,161 503 1.983% 2.239% 1.392% 0.5 0.5 0.58 0.8 0.8 0.7 3.4 4.42 1.7 17 17 1.7Total 374,250 289,635 84,615 1.245% 1.381% 0.779% 0.002 0.0077 0.002 0.94 1 0.7 5.4 6 2.9 5100 5100 740

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A60b. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 16.129% 9.494% 37.671% 24.047% 36.289% 16.426%AL 266 204 62 4,234,433 1,128,788 3,105,645 10.526% 10.294% 11.290% 10.957% 18.756% 8.123%AR 454 382 72 2,453,348 910,322 1,543,026 4.185% 4.712% 1.389% 1.170% 2.738% 0.245%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 6.138% 5.638% 16.667% 12.077% 9.305% 14.376%CA 3,662 3,145 517 35,830,167 13,517,706 22,312,461 4.588% 4.134% 7.350% 31.809% 11.181% 44.306%CO 827 606 221 4,998,841 531,207 4,467,634 6.892% 7.591% 4.977% 6.067% 25.023% 3.813%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 3.977% 4.110% 0.000% 0.889% 6.217% 0.000%DE 318 315 3 698,987 417,587 281,400 5.975% 6.032% 0.000% 13.325% 22.305% 0.000%FL 1,510 1,484 26 17,495,564 15,249,522 2,246,042 2.185% 2.156% 3.846% 3.565% 2.502% 10.780%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 1.976% 1.993% 1.724% 0.482% 0.866% 0.379%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 3.504% 3.226% 12.121% 9.663% 4.997% 15.702%ID 935 878 57 1,093,666 837,604 256,062 3.209% 3.303% 1.754% 18.179% 22.059% 5.488%IL 1,429 1,325 104 9,217,431 3,017,034 6,200,397 2.099% 2.264% 0.000% 1.282% 3.918% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 4.953% 4.895% 6.818% 3.484% 1.721% 5.438%KY 241 92 149 4,602,392 375,363 4,227,029 16.183% 9.783% 20.134% 14.212% 6.367% 14.909%MA 718 600 118 8,557,325 1,749,901 6,807,424 9.610% 9.833% 8.475% 4.637% 10.931% 3.019%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 8.634% 8.418% 11.765% 42.344% 31.235% 45.193%ME 810 757 53 728,347 292,773 435,574 5.679% 5.680% 5.660% 21.442% 5.430% 32.205%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 2.961% 2.851% 8.197% 6.152% 19.093% 1.211%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 10.367% 9.278% 66.667% 20.299% 19.472% 22.291%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 5.928% 5.522% 12.987% 9.654% 15.059% 2.706%MT 848 788 60 757,949 365,280 392,669 2.241% 2.284% 1.667% 3.436% 5.059% 1.927%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 5.999% 6.104% 4.317% 16.641% 16.645% 16.639%ND 210 183 27 562,397 257,172 305,225 5.238% 5.464% 3.704% 2.087% 4.505% 0.049%NE 771 760 11 1,462,181 685,701 776,480 2.464% 2.500% 0.000% 3.906% 8.329% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 11.685% 11.997% 2.439% 6.215% 14.119% 0.478%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 11.445% 11.315% 16.216% 21.742% 17.870% 23.828%NM 727 688 39 1,698,980 1,432,432 266,548 7.428% 7.413% 7.692% 14.923% 9.246% 45.431%NV 338 317 21 973,592 283,701 689,891 7.988% 6.940% 23.810% 43.739% 6.970% 58.859%NY 1,530 1,294 236 4,896,835 1,046,233 3,850,602 3.922% 3.555% 5.932% 1.747% 5.178% 0.815%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 2.829% 2.914% 1.600% 1.419% 2.264% 1.046%OK 718 506 212 3,119,686 660,832 2,458,854 6.825% 7.312% 5.660% 4.681% 15.738% 1.709%OR 1,097 945 152 2,940,119 574,689 2,365,430 1.550% 1.587% 1.316% 1.188% 2.229% 0.936%RI 145 136 9 913,884 173,906 739,978 13.103% 11.029% 44.444% 25.730% 32.786% 24.071%SC 819 757 62 3,356,831 732,879 2,623,952 2.930% 2.906% 3.226% 12.014% 1.373% 14.986%SD 245 233 12 266,416 194,218 72,198 2.041% 2.146% 0.000% 1.528% 2.096% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.855% 0.000% 1.587% 1.774% 0.000% 2.388%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 7.817% 7.377% 13.743% 18.286% 10.607% 22.801%UT 500 454 46 2,553,197 1,698,877 854,320 4.800% 4.405% 8.696% 7.681% 5.012% 12.989%VA 1,601 1,430 171 5,274,208 631,625 4,642,583 4.310% 4.336% 4.094% 3.223% 12.636% 1.942%VT 603 560 43 491,035 227,067 263,968 9.121% 9.464% 4.651% 6.363% 12.809% 0.818%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 10.650% 10.714% 5.000% 14.524% 24.937% 0.073%WV 403 243 160 1,416,020 237,670 1,178,350 6.203% 7.407% 4.375% 2.743% 2.487% 2.794%WY 304 256 48 446,177 129,229 316,948 7.566% 7.422% 8.333% 3.487% 5.782% 2.552%Total 50,451 46,193 4,258 226,955,301 86,403,546 140,551,755 5.764% 5.535% 8.243% 13.215% 9.361% 15.584%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A60c. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 1 1 0 0.034% 0.034% 0.000% 500 500 0 0.007% 0.025% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 1 0 0.002% 0.002% 0.000% 500 500 0 0.0002% 0.001% 0.000%

Percent of Population Served 

with At Least One Detection 

> 1,000 μg/L

State

Number of Systems 

with At Least One Detection 

> 1,000 μg/L

Percent of Systems 

with At Least One Detection 

> 1,000 μg/L

Population Served by Systems 

with At Least One Detection 

> 1,000 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A60d. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 1 1 0 0.121% 0.165% 0.000% 425 425 0 0.009% 0.080% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 2 2 0 0.214% 0.228% 0.000% 10,137 10,137 0 0.927% 1.210% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 4 4 0 0.135% 0.137% 0.000% 1,745 1,745 0 0.024% 0.088% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 2 2 0 0.236% 0.254% 0.000% 579 579 0 0.076% 0.159% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 1 1 0 0.072% 0.073% 0.000% 85 85 0 0.001% 0.003% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 2 2 0 0.131% 0.155% 0.000% 801 801 0 0.016% 0.077% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 1 1 0 0.166% 0.179% 0.000% 1,695 1,695 0 0.345% 0.746% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.496% 0.412% 0.625% 1,834 222 1,612 0.130% 0.093% 0.137%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 15 14 1 0.030% 0.030% 0.023% 17,301 15,689 1,612 0.008% 0.018% 0.001%

Percent of Population Served 

with At Least One Detection 

}	


State

Number of Systems 

with At Least One Detection 

}	


Percent of Systems 

with At Least One Detection 

}	


Population Served by Systems 

with At Least One Detection 

}	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A60e. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 1 1 0 0.121% 0.165% 0.000% 425 425 0 0.009% 0.080% 0.000%CT 1 1 0 0.083% 0.086% 0.000% 68 68 0 0.002% 0.017% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 2 2 0 0.214% 0.228% 0.000% 10,137 10,137 0 0.927% 1.210% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 4 4 0 0.135% 0.137% 0.000% 1,745 1,745 0 0.024% 0.088% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 2 2 0 0.236% 0.254% 0.000% 579 579 0 0.076% 0.159% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 1 1 0 0.072% 0.073% 0.000% 85 85 0 0.001% 0.003% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 4 2 2 0.261% 0.155% 0.847% 5,401 801 4,600 0.110% 0.077% 0.119%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 1 1 0 0.166% 0.179% 0.000% 1,695 1,695 0 0.345% 0.746% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 2 1 1 0.496% 0.412% 0.625% 1,834 222 1,612 0.130% 0.093% 0.137%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 18 15 3 0.036% 0.032% 0.070% 21,969 15,757 6,212 0.010% 0.018% 0.004%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A61. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 3 μg/L 27,718 5 0.018% 60,886,049 27,063 0.044%

	
 27,718 7 0.025% 60,886,049 27,713 0.046%

> 1 μg/L 27,718 7 0.025% 60,886,049 27,713 0.046%> 3 μg/L 2,669 0 0.000% 99,126,085 0 0.000%

	
 2,669 2 0.075% 99,126,085 257,737 0.260%

> 1 μg/L 2,669 2 0.075% 99,126,085 257,737 0.260%> 3 μg/L 30,387 5 0.016% 160,012,134 27,063 0.017%

	
 30,387 9 0.030% 160,012,134 285,450 0.178%

> 1 μg/L 30,387 9 0.030% 160,012,134 285,450 0.178%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A61a. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 66 46 20 0.000% 0.000% 0.000%AL 499 370 129 0.000% 0.000% 0.000%AR 1,664 1,423 241 0.060% 0.070% 0.000% 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2AZ 6,809 5,378 1,431 0.000% 0.000% 0.000%CA 12,542 7,285 5,257 0.000% 0.000% 0.000%CO 2,524 1,823 701 0.000% 0.000% 0.000%CT 1,774 1,184 590 0.451% 0.084% 1.186% 1 2 1 1 2 1 2 2 1 2 2 1DE 275 257 18 0.000% 0.000% 0.000%FL 2,376 2,311 65 0.505% 0.519% 0.000% 0.04 0.04 0.04 0.04 0.1 0.1 0.9 0.9GA 1,429 1,350 79 0.280% 0.296% 0.000% 5 5 5 5 5 5 5 5HI 1,946 1,849 97 0.000% 0.000% 0.000%IA 42 29 13 0.000% 0.000% 0.000%ID 1,732 1,476 256 0.000% 0.000% 0.000%IL 4,676 3,944 732 0.000% 0.000% 0.000%IN 2,229 2,063 166 0.000% 0.000% 0.000%KY 1,713 439 1,274 0.350% 0.000% 0.471% 0.07 0.07 1.5 1.5 2.5 2.5 2.5 2.5MA 2,966 2,189 777 0.135% 0.046% 0.386% 1 1 1 1 1 1 1 1 1 1 1 1MD 428 76 352 0.000% 0.000% 0.000%ME 387 339 48 0.000% 0.000% 0.000%MI 6,875 6,423 452 0.000% 0.000% 0.000%MN 4,761 4,620 141 0.000% 0.000% 0.000%MO 5,237 4,499 738 0.000% 0.000% 0.000%MT 2,992 2,691 301 0.000% 0.000% 0.000%NC 13,219 12,111 1,108 0.227% 0.239% 0.090% 1 1 1.72 3.465 3.63 1.72 5.1 5.3 1.72 6.8 6.8 1.72ND 409 341 68 0.000% 0.000% 0.000%NE 1,355 1,320 35 0.000% 0.000% 0.000%NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 5 5 0 0.000% 0.000% 0.000%NM 4,335 4,086 249 0.046% 0.049% 0.000% 0.15 0.15 0.32 0.32 0.49 0.49 0.49 0.49NV 1,523 1,141 382 0.000% 0.000% 0.000%NY 2,879 2,169 710 0.035% 0.046% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1OH 192 75 117 0.000% 0.000% 0.000%OKOR 2,052 1,569 483 0.000% 0.000% 0.000%RI 598 411 187 0.000% 0.000% 0.000%SC 2,920 2,527 393 0.000% 0.000% 0.000%SD 953 844 109 0.000% 0.000% 0.000%TN 65 12 53 0.000% 0.000% 0.000%TX 770 753 17 0.000% 0.000% 0.000%UT 7,110 5,922 1,188 0.000% 0.000% 0.000%VA 500 178 322 0.000% 0.000% 0.000%VT 1,283 1,095 188 0.078% 0.091% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5WI 3,177 3,082 95 0.000% 0.000% 0.000%WV 645 335 310 1.860% 2.090% 1.613% 0.1 0.24 0.1 0.34 0.24 0.34 0.5 0.34 1 1 0.34 1WY 1,278 958 320 0.000% 0.000% 0.000%Total 115,403 94,872 20,531 0.070% 0.062% 0.107% 0.04 0.04 0.07 1 1.5 1 4.9 5 2.5 6.8 6.8 2.5

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A61b. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 15 10 5 24,205 14,306 9,899 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 171 126 45 2,702,037 589,449 2,112,588 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 450 379 71 2,447,627 905,863 1,541,764 0.222% 0.264% 0.000% 0.201% 0.544% 0.000%AZ 949 901 48 6,081,248 2,710,657 3,370,591 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CA 1,593 1,307 286 33,236,213 11,569,633 21,666,580 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CO 812 593 219 4,992,325 525,416 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 663 625 38 2,596,535 262,648 2,333,887 0.754% 0.160% 10.526% 17.142% 0.168% 19.052%DE 115 112 3 480,758 199,358 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,309 1,288 21 16,785,212 14,546,036 2,239,176 0.458% 0.466% 0.000% 15.517% 17.905% 0.000%GA 294 280 14 990,475 298,453 692,022 1.361% 1.429% 0.000% 2.702% 8.968% 0.000%HI 100 88 12 1,256,886 1,202,258 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 4 3 1 162,197 27,580 134,617 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 716 670 46 978,793 742,327 236,466 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,371 1,267 104 9,186,700 2,986,303 6,200,397 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,401 1,357 44 4,866,641 2,546,905 2,319,736 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%KY 242 93 149 4,602,489 375,460 4,227,029 1.653% 0.000% 2.685% 8.236% 0.000% 8.967%MA 644 527 117 8,485,078 1,682,696 6,802,382 0.466% 0.190% 1.709% 0.740% 0.351% 0.836%MD 72 39 33 4,101,506 149,836 3,951,670 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ME 228 204 24 473,968 103,532 370,436 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,935 2,874 61 7,227,231 2,047,375 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,287 1,258 29 3,934,332 2,684,691 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,384 1,308 76 2,624,615 1,680,154 944,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 813 753 60 753,259 360,590 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.127% 0.090% 0.730% 0.055% 0.029% 0.064%ND 209 182 27 559,198 253,973 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 692 681 11 1,442,549 666,069 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 2 2 0 6,121 6,121 0 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 694 658 36 1,662,842 1,399,944 262,898 0.288% 0.304% 0.000% 0.022% 0.026% 0.000%NV 288 267 21 960,034 270,143 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,348 1,117 231 4,924,818 981,541 3,943,277 0.074% 0.090% 0.000% 0.001% 0.006% 0.000%OH 46 36 10 3,527,456 136,924 3,390,532 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OKOR 1,084 934 150 2,937,104 572,354 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 85 76 9 901,461 161,483 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 775 716 59 3,436,445 809,662 2,626,783 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 261 240 21 622,272 263,101 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 13 6 7 675,214 145,112 530,102 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 617 609 8 508,429 469,714 38,715 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 427 390 37 2,500,736 1,667,550 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 182 71 111 2,391,215 30,317 2,360,898 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 438 405 33 436,614 185,450 251,164 0.228% 0.247% 0.000% 0.071% 0.166% 0.000%WI 1,410 1,390 20 3,883,918 2,192,174 1,691,744 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%WV 342 196 146 1,368,270 204,156 1,164,114 2.924% 3.571% 2.055% 0.789% 0.640% 0.815%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 30,387 27,718 2,669 160,012,134 60,886,049 99,126,085 0.132% 0.094% 0.525% 2.211% 4.344% 0.901%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A61c. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 4 4 0 1.361% 1.429% 0.000% 26,765 26,765 0 2.702% 8.968% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 1 0 0.042% 0.045% 0.000% 298 298 0 0.004% 0.017% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 5 5 0 0.016% 0.018% 0.000% 27,063 27,063 0 0.017% 0.044% 0.000%

Percent of Population Served 

with At Least One Detection 

> 3 μg/L

State

Number of Systems 

with At Least One Detection 

> 3 μg/L

Percent of Systems 

with At Least One Detection 

> 3 μg/L

Population Served by Systems 

with At Least One Detection 

> 3 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A61d. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.151% 0.160% 0.000% 440 440 0 0.017% 0.168% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 4 4 0 1.361% 1.429% 0.000% 26,765 26,765 0 2.702% 8.968% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 254,462 0 254,462 5.529% 0.000% 6.020%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 2 1 0.127% 0.090% 0.730% 3,783 508 3,275 0.055% 0.029% 0.064%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 9 7 2 0.030% 0.025% 0.075% 285,450 27,713 257,737 0.178% 0.046% 0.260%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A61e. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.151% 0.160% 0.000% 440 440 0 0.017% 0.168% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 4 4 0 1.361% 1.429% 0.000% 26,765 26,765 0 2.702% 8.968% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.413% 0.000% 0.671% 254,462 0 254,462 5.529% 0.000% 6.020%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 3 2 1 0.127% 0.090% 0.730% 3,783 508 3,275 0.055% 0.029% 0.064%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 9 7 2 0.030% 0.025% 0.075% 285,450 27,713 257,737 0.178% 0.046% 0.260%

Percent of Population Served 

with At Least One Detection 

> 1 μg/L

State

Number of Systems 

with At Least One Detection 

> 1 μg/L

Percent of Systems 

with At Least One Detection 

> 1 μg/L

Population Served by Systems 

with At Least One Detection 

> 1 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A62. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 70 μg/L 45,887 0 0.000% 86,306,318 0 0.000%	
 45,887 2 0.004% 86,306,318 2,131 0.002%

> 70 μg/L 4,248 0 0.000% 140,535,784 0 0.000%	
 4,248 0 0.000% 140,535,784 0 0.000%> 70 μg/L 50,135 0 0.000% 226,842,102 0 0.000%	
 50,135 2 0.004% 226,842,102 2,131 0.001%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A62a. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,113 1,976 1,137 0.128% 0.152% 0.088% 0.25 0.38 0.25 0.61 0.84 0.25 2.9 2.9 0.25 2.9 2.9 0.25AL 820 596 224 0.000% 0.000% 0.000%AR 2,383 1,915 468 0.504% 0.522% 0.427% 0.11 0.11 0.11 0.135 0.135 0.175 0.24 0.26 0.24 0.29 0.29 0.24AZ 11,713 9,543 2,170 0.034% 0.010% 0.138% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5CA 84,520 44,744 39,776 0.012% 0.011% 0.013% 0.53 0.6 0.53 1.3 0.84 1.4 6.1 2.2 10 10 2.2 10CO 2,871 2,131 740 0.383% 0.469% 0.135% 0.04 0.04 0.05 0.08 0.08 0.05 0.52 0.61 0.05 0.7 0.7 0.05CT 6,937 6,046 891 0.086% 0.099% 0.000% 0.7 0.7 1 1 1.1 1.1 1.1 1.1DE 1,047 1,017 30 0.000% 0.000% 0.000%FL 4,143 4,075 68 0.169% 0.172% 0.000% 0.09 0.09 0.12 0.12 0.5 0.5 0.5 0.5GA 7,176 6,349 827 0.000% 0.000% 0.000%HI 1,789 1,686 103 0.000% 0.000% 0.000%IA 1,762 1,637 125 0.000% 0.000% 0.000%ID 3,764 3,303 461 0.000% 0.000% 0.000%IL 6,523 5,969 554 0.015% 0.017% 0.000% 0.65 0.65 0.65 0.65 0.65 0.65 0.65 0.65IN 4,621 4,311 310 0.022% 0.023% 0.000% 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5KY 3,312 1,125 2,187 0.332% 0.000% 0.503% 0.003 0.003 0.12 0.12 0.5 0.5 1 1MA 16,249 12,259 3,990 0.006% 0.008% 0.000% 1 1 1 1 1 1 1 1MD 6,768 5,506 1,262 0.044% 0.054% 0.000% 0.6 0.6 1.8 1.8 1.9 1.9 1.9 1.9ME 3,696 3,381 315 0.000% 0.000% 0.000%MI 10,753 9,743 1,010 0.000% 0.000% 0.000%MN 8,581 7,332 1,249 0.000% 0.000% 0.000%MO 7,544 6,695 849 0.080% 0.090% 0.000% 0.5 0.5 0.725 0.725 1.22 1.22 1.22 1.22MT 4,493 3,953 540 0.000% 0.000% 0.000%NC 19,035 17,455 1,580 0.079% 0.086% 0.000% 0.5 0.5 1.2 1.2 70 70 70 70ND 543 411 132 0.000% 0.000% 0.000%NE 6,844 6,265 579 0.000% 0.000% 0.000%NH 9,581 9,103 478 0.073% 0.077% 0.000% 0.5 0.5 0.76 0.76 2.9 2.9 2.9 2.9NJ 20,349 18,561 1,788 0.074% 0.075% 0.056% 0.05 0.05 0.7 0.35 0.34 0.7 0.99 0.99 0.7 1 1 0.7NM 6,577 6,101 476 0.046% 0.049% 0.000% 0.2 0.2 0.3 0.3 0.5 0.5 0.5 0.5NV 3,209 2,576 633 0.031% 0.039% 0.000% 5.5 5.5 5.5 5.5 5.5 5.5 5.5 5.5NY 7,099 5,429 1,670 0.099% 0.092% 0.120% 0.5 0.5 0.5 0.5 0.5 0.5 9.5 9.5 0.5 9.5 9.5 0.5OH 8,828 7,672 1,156 0.068% 0.078% 0.000% 0.5 0.5 1.82 1.82 9.3 9.3 9.3 9.3OK 5,638 4,202 1,436 0.018% 0.000% 0.070% 0.91 0.91 0.91 0.91 0.91 0.91 0.91 0.91OR 2,324 1,682 642 0.043% 0.059% 0.000% 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61RI 1,957 1,589 368 0.000% 0.000% 0.000%SC 4,324 3,787 537 0.023% 0.026% 0.000% 0.56 0.56 0.56 0.56 0.56 0.56 0.56 0.56SD 889 855 34 0.112% 0.117% 0.000% 0.66 0.66 0.66 0.66 0.66 0.66 0.66 0.66TN 2,946 1,166 1,780 0.000% 0.000% 0.000%TX 34,148 27,042 7,106 0.061% 0.055% 0.084% 0.5 0.5 0.6 0.7 0.6 0.8 2.74 2.82 0.9 2.82 2.82 0.9UT 8,981 7,555 1,426 0.000% 0.000% 0.000%VA 4,928 4,055 873 0.264% 0.321% 0.000% 0.6 0.6 0.9 0.9 1.5 1.5 1.7 1.7VT 4,271 3,884 387 0.023% 0.026% 0.000% 0.95 0.95 0.95 0.95 0.95 0.95 0.95 0.95WI 11,293 11,168 125 0.027% 0.027% 0.000% 0.02 0.02 0.37 0.37 0.8 0.8 0.8 0.8WV 1,134 443 691 1.499% 2.709% 0.724% 0.24 0.24 0.4 0.5 0.5 0.5 1 0.5 1 4.97 4.97 1WY 1,656 1,153 503 0.000% 0.000% 0.000%Total 371,132 287,446 83,686 0.051% 0.053% 0.045% 0.003 0.02 0.003 0.6 0.6 0.5 2.2 2.74 1.2 70 70 10

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A62b. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.645% 0.633% 0.685% 0.175% 0.226% 0.143%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 2.643% 2.618% 2.778% 1.673% 3.769% 0.437%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.189% 0.099% 2.083% 4.877% 0.026% 8.901%CA 3,595 3,083 512 35,819,126 13,507,460 22,311,666 0.250% 0.130% 0.977% 1.379% 0.967% 1.628%CO 826 605 221 4,997,841 530,207 4,467,634 1.090% 1.322% 0.452% 0.145% 1.326% 0.005%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.083% 0.086% 0.000% 0.001% 0.007% 0.000%DE 318 315 3 698,987 417,587 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,510 1,484 26 17,495,564 15,249,522 2,246,042 0.331% 0.337% 0.000% 1.824% 2.093% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,184 1,084 100 9,132,188 2,936,410 6,195,778 0.084% 0.092% 0.000% 0.005% 0.017% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.068% 0.070% 0.000% 0.001% 0.002% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 2.075% 0.000% 3.356% 7.905% 0.000% 8.607%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.139% 0.167% 0.000% 0.289% 1.413% 0.000%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.190% 0.203% 0.000% 0.000% 0.002% 0.000%ME 810 757 53 728,347 292,773 435,574 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.423% 0.448% 0.000% 0.559% 0.993% 0.000%MT 848 788 60 757,949 365,280 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.634% 0.673% 0.000% 0.062% 0.249% 0.000%ND 209 182 27 562,332 257,107 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 0.556% 0.575% 0.000% 0.372% 0.885% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 1.073% 1.029% 2.703% 1.789% 3.525% 0.854%NM 727 688 39 1,698,980 1,432,432 266,548 0.413% 0.436% 0.000% 5.015% 5.948% 0.000%NV 338 317 21 973,592 283,701 689,891 0.296% 0.315% 0.000% 0.003% 0.009% 0.000%NY 1,525 1,289 236 4,895,099 1,044,497 3,850,602 0.459% 0.388% 0.847% 0.097% 0.423% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.309% 0.330% 0.000% 0.042% 0.138% 0.000%OK 730 518 212 3,123,687 664,833 2,458,854 0.137% 0.000% 0.472% 0.063% 0.000% 0.080%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.091% 0.106% 0.000% 0.002% 0.011% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 817 755 62 3,356,049 732,097 2,623,952 0.122% 0.132% 0.000% 0.003% 0.016% 0.000%SD 245 233 12 266,416 194,218 72,198 0.408% 0.429% 0.000% 0.176% 0.242% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.323% 0.260% 1.170% 0.647% 0.404% 0.790%UT 500 454 46 2,553,197 1,698,877 854,320 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 0.563% 0.630% 0.000% 0.089% 0.742% 0.000%VT 603 560 43 491,035 227,067 263,968 0.166% 0.179% 0.000% 0.018% 0.040% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.168% 0.170% 0.000% 0.034% 0.058% 0.000%WV 400 240 160 1,415,792 237,442 1,178,350 4.000% 5.000% 2.500% 2.503% 1.177% 2.770%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,135 45,887 4,248 226,842,102 86,306,318 140,535,784 0.321% 0.292% 0.636% 0.889% 0.903% 0.880%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A62c. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 70 μg/L

State

Number of Systems 

with At Least One Detection 

> 70 μg/L

Percent of Systems 

with At Least One Detection 

> 70 μg/L

Population Served by Systems 

with At Least One Detection 

> 70 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A62d. 1,2,4-Trichlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 2 2 0 0.084% 0.090% 0.000% 2,131 2,131 0 0.030% 0.123% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 2 0 0.004% 0.004% 0.000% 2,131 2,131 0 0.001% 0.002% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A63. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 200 μg/L 46,183 2 0.004% 86,390,348 226 0.000%

	
 46,183 2 0.004% 86,390,348 226 0.000%

> 200 μg/L 4,257 0 0.000% 140,541,198 0 0.000%

	
 4,257 0 0.000% 140,541,198 0 0.000%

> 200 μg/L 50,440 2 0.004% 226,931,546 226 0.000%

	
 50,440 2 0.004% 226,931,546 226 0.000%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A63a. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,105 1,968 1,137 1.127% 1.677% 0.176% 0.3 0.3 0.34 1.3 1.34 0.34 15.4 15.4 0.34 39.6 39.6 0.34AL 850 626 224 4.235% 5.751% 0.000% 0.5 0.5 0.795 0.795 1.4 1.4 2.4 2.4AR 2,394 1,926 468 0.084% 0.104% 0.000% 0.2 0.2 0.825 0.825 1.45 1.45 1.45 1.45AZ 12,599 9,548 3,051 0.087% 0.063% 0.164% 0.5 0.6 0.5 0.7 0.75 0.5 2 2 4.2 4.2 2 4.2CA 86,649 45,586 41,063 1.144% 0.847% 1.473% 0.5 0.5 0.5 1 1.2 0.99 4.7 7.5 4.1 92 14 92CO 2,874 2,134 740 0.070% 0.094% 0.000% 0.51 0.51 0.555 0.555 0.6 0.6 0.6 0.6CT 6,938 6,047 891 2.681% 2.431% 4.377% 0.5 0.5 0.5 1.615 1.8 1.4 8.79 10.6 3.3 29.8 29.8 4.3DE 1,048 1,019 29 0.286% 0.294% 0.000% 0.5 0.5 0.51 0.51 1.67 1.67 1.67 1.67FL 4,147 4,079 68 0.096% 0.098% 0.000% 0.08 0.08 0.21 0.21 0.42 0.42 0.42 0.42GA 7,176 6,349 827 0.111% 0.126% 0.000% 0.5 0.5 0.595 0.595 0.9 0.9 0.9 0.9HI 1,792 1,689 103 0.000% 0.000% 0.000%IA 1,789 1,660 129 1.062% 0.843% 3.876% 0.5 0.5 0.6 2.1 3.75 0.7 6.1 6.1 0.7 8.2 8.2 0.7ID 3,764 3,303 461 0.213% 0.242% 0.000% 0.3 0.3 0.53 0.53 7.2 7.2 7.2 7.2IL 7,030 6,464 566 2.575% 2.800% 0.000% 0.5 0.5 1.4 1.4 5.3 5.3 1400 1400IN 4,621 4,311 310 1.536% 1.647% 0.000% 0.5 0.5 1.9 1.9 8.5 8.5 60 60KY 3,313 1,126 2,187 0.483% 1.066% 0.183% 0.1 0.1 0.5 0.5 0.45 0.5 3.2 3.2 1 3.3 3.3 1MA 16,249 12,259 3,990 1.612% 1.746% 1.203% 0.4 0.4 0.5 1 1 1 11 14 6.3 63 63 14.9MD 6,772 5,510 1,262 1.270% 1.053% 2.219% 0.2 0.4 0.2 1 0.9 3.5 5.6 2.8 6.4 38 38 17.6ME 3,698 3,383 315 1.001% 1.094% 0.000% 0.48 0.48 0.9 0.9 16 16 31 31MI 10,754 9,744 1,010 0.567% 0.626% 0.000% 0.4 0.4 0.6 0.6 1.8 1.8 4.1 4.1MN 8,582 7,333 1,249 0.839% 0.955% 0.160% 0.2 0.2 0.2 0.5 0.5 0.25 2.4 2.4 0.3 4.7 4.7 0.3MO 7,544 6,695 849 0.066% 0.075% 0.000% 0.6 0.6 0.8 0.8 0.9 0.9 0.9 0.9MT 4,495 3,956 539 0.311% 0.354% 0.000% 0.59 0.59 2.95 2.95 16 16 29 29NC 19,068 17,488 1,580 0.273% 0.280% 0.190% 0.5 0.5 0.57 1.215 1.26 0.6 11 12.8 0.6 44.6 44.6 0.6ND 552 417 135 0.725% 0.959% 0.000% 1.22 1.22 3.9 3.9 9.17 9.17 9.17 9.17NE 6,844 6,265 579 0.687% 0.750% 0.000% 0.17 0.17 1.08 1.08 5.5 5.5 16 16NH 9,600 9,115 485 0.771% 0.669% 2.680% 0.009 0.009 0.57 1.2 1.29 1 2.38 2.3 9.2 9.5 8.1 9.5NJ 20,364 18,576 1,788 2.932% 2.988% 2.349% 0.04 0.04 0.2 0.82 0.88 0.6 3.77 3.98 1 11.8 11.8 1.9NM 6,577 6,101 476 0.334% 0.361% 0.000% 0.2 0.2 0.5 0.5 2.1 2.1 3 3NV 3,209 2,577 632 0.530% 0.660% 0.000% 0.1 0.1 0.67 0.67 1.4 1.4 6.01 6.01NY 7,092 5,424 1,668 0.874% 1.088% 0.180% 0.4 0.4 0.5 1.15 1.3 0.5 6.9 7.2 0.5 500 500 0.5OH 8,856 7,694 1,162 0.926% 1.053% 0.086% 0.5 0.5 0.59 1.5 1.5 0.59 6.1 6.1 0.59 68.9 68.9 0.59OK 5,636 4,201 1,435 0.035% 0.024% 0.070% 0.5 0.5 0.6 0.55 0.5 0.6 0.6 0.5 0.6 0.6 0.5 0.6OR 2,327 1,685 642 1.031% 1.424% 0.000% 0.5 0.5 0.685 0.685 1 1 1.7 1.7RI 1,959 1,591 368 1.940% 2.388% 0.000% 0.4 0.4 0.8 0.8 2 2 6 6SC 4,342 3,803 539 0.184% 0.210% 0.000% 0.54 0.54 3.76 3.76 7 7 7 7SD 889 855 34 0.225% 0.234% 0.000% 0.51 0.51 1.335 1.335 2.16 2.16 2.16 2.16TN 2,946 1,166 1,780 0.170% 0.429% 0.000% 0.5 0.5 0.8 0.8 1.6 1.6 1.6 1.6TX 34,146 27,042 7,104 0.056% 0.067% 0.014% 0.5 0.5 7.8 0.8 0.77 7.8 2.7 2.6 7.8 7.8 2.7 7.8UT 8,990 7,559 1,431 0.000% 0.000% 0.000%VA 4,930 4,057 873 0.385% 0.468% 0.000% 0.8 0.8 2.1 2.1 6.7 6.7 11 11VT 4,350 3,956 394 0.920% 1.011% 0.000% 0.3 0.3 0.855 0.855 2.9 2.9 4.3 4.3WI 11,292 11,167 125 2.993% 3.018% 0.800% 0.03 0.03 0.41 0.55 0.55 0.41 6.3 6.3 0.41 34 34 0.41WV 1,140 444 696 4.035% 7.432% 1.868% 0.17 0.17 0.4 1.55 2.8 1 4.4 4.4 2 6 5.5 6WY 1,658 1,155 503 0.181% 0.260% 0.000% 0.5 0.5 0.7 0.7 8.02 8.02 8.02 8.02Total 374,950 289,053 85,897 0.963% 0.967% 0.950% 0.009 0.009 0.2 1 1 0.97 5.2 5.6 4.3 1400 1400 92

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A63b. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 1.452% 1.688% 0.685% 8.233% 21.443% 0.009%AL 263 202 61 4,218,278 1,123,190 3,095,088 1.521% 1.980% 0.000% 0.773% 2.904% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.441% 0.524% 0.000% 0.187% 0.503% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.567% 0.297% 6.250% 8.667% 1.938% 14.250%CA 3,653 3,136 517 35,828,228 13,515,767 22,312,461 0.602% 0.415% 1.741% 19.948% 6.400% 28.155%CO 826 605 221 4,997,841 530,207 4,467,634 0.242% 0.331% 0.000% 0.003% 0.024% 0.000%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 1.823% 1.627% 7.692% 6.306% 6.725% 6.236%DE 318 315 3 698,987 417,587 281,400 0.314% 0.317% 0.000% 0.044% 0.073% 0.000%FL 1,509 1,483 26 17,495,514 15,249,472 2,246,042 0.265% 0.270% 0.000% 0.753% 0.864% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.055% 0.059% 0.000% 0.001% 0.003% 0.000%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.473% 0.391% 3.030% 3.172% 5.292% 0.430%ID 935 878 57 1,093,666 837,604 256,062 0.642% 0.683% 0.000% 0.126% 0.164% 0.000%IL 1,430 1,326 104 9,217,581 3,017,184 6,200,397 0.909% 0.980% 0.000% 2.144% 6.551% 0.000%IN 1,472 1,428 44 4,885,505 2,565,769 2,319,736 1.155% 1.190% 0.000% 4.710% 8.968% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 2.490% 2.174% 2.685% 2.477% 1.236% 2.587%MA 718 600 118 8,557,325 1,749,901 6,807,424 4.596% 4.500% 5.085% 4.691% 17.877% 1.302%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 1.613% 1.217% 7.353% 35.327% 4.799% 43.156%ME 810 757 53 728,347 292,773 435,574 0.988% 1.057% 0.000% 2.213% 5.506% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.538% 0.550% 0.000% 0.754% 2.730% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 1.454% 1.418% 3.333% 4.624% 6.185% 0.862%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.282% 0.299% 0.000% 0.201% 0.357% 0.000%MT 848 788 60 757,949 365,280 392,669 0.354% 0.381% 0.000% 0.074% 0.154% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 1.098% 1.032% 2.158% 0.873% 0.485% 1.001%ND 210 183 27 562,397 257,172 305,225 0.952% 1.093% 0.000% 9.587% 20.966% 0.000%NE 771 760 11 1,462,181 685,701 776,480 1.038% 1.053% 0.000% 4.826% 10.290% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 1.908% 1.726% 7.317% 9.181% 6.543% 11.095%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 6.795% 6.539% 16.216% 30.649% 21.470% 35.594%NM 727 688 39 1,698,980 1,432,432 266,548 0.963% 1.017% 0.000% 0.194% 0.230% 0.000%NV 338 317 21 973,592 283,701 689,891 1.183% 1.262% 0.000% 2.770% 9.505% 0.000%NY 1,524 1,288 236 4,894,939 1,044,337 3,850,602 1.444% 1.475% 1.271% 7.693% 10.081% 7.045%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.772% 0.770% 0.800% 0.393% 1.281% 0.001%OK 730 518 212 3,123,687 664,833 2,458,854 0.274% 0.193% 0.472% 0.049% 0.024% 0.055%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.182% 0.212% 0.000% 1.041% 5.325% 0.000%RI 145 136 9 913,884 173,906 739,978 4.828% 5.147% 0.000% 2.953% 15.519% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.244% 0.264% 0.000% 0.020% 0.093% 0.000%SD 245 233 12 266,416 194,218 72,198 0.816% 0.858% 0.000% 0.349% 0.479% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.285% 0.617% 0.000% 0.027% 0.104% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.121% 0.108% 0.292% 0.033% 0.033% 0.032%UT 500 454 46 2,553,197 1,698,877 854,320 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 1,599 1,428 171 5,273,058 630,475 4,642,583 0.250% 0.280% 0.000% 0.010% 0.085% 0.000%VT 603 560 43 491,035 227,067 263,968 1.161% 1.250% 0.000% 1.081% 2.337% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 3.307% 3.288% 5.000% 12.784% 20.526% 2.039%WV 403 243 160 1,416,020 237,670 1,178,350 4.963% 6.584% 2.500% 3.436% 2.033% 3.718%WY 304 256 48 446,177 129,229 316,948 0.987% 1.172% 0.000% 0.334% 1.155% 0.000%Total 50,440 46,183 4,257 226,931,546 86,390,348 140,541,198 1.075% 1.052% 1.315% 6.559% 4.369% 7.905%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A63c. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 150 150 0 0.002% 0.005% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 76 76 0 0.002% 0.007% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 2 0 0.004% 0.004% 0.000% 226 226 0 0.0001% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 200 μg/L

State

Number of Systems 

with At Least One Detection 

> 200 μg/L

Percent of Systems 

with At Least One Detection 

> 200 μg/L

Population Served by Systems 

with At Least One Detection 

> 200 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A63d. 1,1,1-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.070% 0.075% 0.000% 150 150 0 0.002% 0.005% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 76 76 0 0.002% 0.007% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 2 2 0 0.004% 0.004% 0.000% 226 226 0 0.0001% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A64. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 45,942 5 0.011% 86,314,890 20,910 0.024%	
 45,942 7 0.015% 86,314,890 31,838 0.037%

	
 45,942 8 0.017% 86,314,890 31,882 0.037%

> 5 μg/L 4,253 2 0.047% 140,536,579 105,441 0.075%	
 4,253 5 0.118% 140,536,579 320,808 0.228%

	
 4,253 5 0.118% 140,536,579 320,808 0.228%

> 5 μg/L 50,195 7 0.014% 226,851,469 126,351 0.056%	
 50,195 12 0.024% 226,851,469 352,646 0.155%

	
 50,195 13 0.026% 226,851,469 352,690 0.155%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A64a. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,107 1,970 1,137 0.097% 0.102% 0.088% 0.12 0.12 1.31 0.55 0.335 1.31 1.31 0.55 1.31 1.31 0.55 1.31AL 820 596 224 0.000% 0.000% 0.000%AR 2,394 1,926 468 0.084% 0.052% 0.214% 0.15 0.3 0.15 0.225 0.3 0.15 0.3 0.3 0.15 0.3 0.3 0.15AZ 11,718 9,550 2,168 0.026% 0.000% 0.138% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5CA 85,674 45,401 40,273 0.133% 0.004% 0.278% 0.5 1 0.5 0.7 4.9 0.7 3 8.8 2.9 40 8.8 40CO 2,865 2,126 739 0.175% 0.047% 0.541% 0.1 0.2 0.1 0.2 0.2 0.25 0.8 0.2 0.8 0.8 0.2 0.8CT 6,938 6,047 891 0.043% 0.050% 0.000% 0.74 0.74 2.3 2.3 4.3 4.3 4.3 4.3DE 1,048 1,018 30 0.000% 0.000% 0.000%FL 4,147 4,079 68 0.145% 0.147% 0.000% 0.08 0.08 0.265 0.265 0.89 0.89 0.89 0.89GA 7,176 6,349 827 0.042% 0.032% 0.121% 0.56 18 0.56 18 27 0.56 36 36 0.56 36 36 0.56HI 1,789 1,686 103 0.000% 0.000% 0.000%IA 1,762 1,637 125 0.000% 0.000% 0.000%ID 3,765 3,304 461 0.000% 0.000% 0.000%IL 6,519 5,965 554 0.031% 0.034% 0.000% 0.52 0.52 3.06 3.06 5.6 5.6 5.6 5.6IN 4,621 4,311 310 0.022% 0.023% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5KY 3,312 1,125 2,187 0.211% 0.089% 0.274% 0.04 0.5 0.04 0.5 0.5 0.5 1 0.5 1 1 0.5 1MA 16,249 12,259 3,990 0.006% 0.000% 0.025% 0.68 0.68 0.68 0.68 0.68 0.68 0.68 0.68MD 6,770 5,509 1,261 0.074% 0.036% 0.238% 0.5 0.6 0.5 0.6 1.3 0.6 2 2 1.8 2 2 1.8ME 3,698 3,383 315 0.027% 0.030% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5MI 10,753 9,743 1,010 0.000% 0.000% 0.000%MN 8,584 7,335 1,249 0.280% 0.286% 0.240% 0.2 0.2 0.2 0.6 0.6 0.2 1.1 1.1 0.2 1.2 1.2 0.2MO 7,544 6,695 849 0.000% 0.000% 0.000%MT 4,491 3,952 539 0.022% 0.025% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5NC 19,065 17,486 1,579 0.016% 0.006% 0.127% 0.54 0.54 0.86 0.86 0.54 2 3.14 0.54 3.14 3.14 0.54 3.14ND 552 417 135 0.000% 0.000% 0.000%NE 6,844 6,265 579 0.029% 0.032% 0.000% 0.55 0.55 0.675 0.675 0.8 0.8 0.8 0.8NH 9,581 9,103 478 0.000% 0.000% 0.000%NJ 20,362 18,574 1,788 0.108% 0.118% 0.000% 0.21 0.21 1.02 1.02 1.8 1.8 2.6 2.6NM 6,577 6,101 476 0.000% 0.000% 0.000%NV 3,207 2,574 633 0.000% 0.000% 0.000%NY 7,078 5,410 1,668 0.113% 0.111% 0.120% 0.5 0.5 0.5 0.5 0.65 0.5 10.1 10.1 0.5 10.1 10.1 0.5OH 8,848 7,686 1,162 0.011% 0.013% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5OK 5,634 4,199 1,435 0.000% 0.000% 0.000%OR 2,324 1,682 642 0.000% 0.000% 0.000%RI 1,959 1,591 368 0.000% 0.000% 0.000%SC 4,344 3,805 539 0.000% 0.000% 0.000%SD 889 855 34 0.000% 0.000% 0.000%TN 2,937 1,165 1,772 0.000% 0.000% 0.000%TX 34,144 27,040 7,104 0.000% 0.000% 0.000%UT 8,979 7,555 1,424 0.011% 0.013% 0.000% 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5VA 4,931 4,058 873 0.000% 0.000% 0.000%VT 4,349 3,955 394 0.046% 0.051% 0.000% 0.3 0.3 0.65 0.65 1 1 1 1WI 11,290 11,165 125 0.027% 0.027% 0.000% 0.01 0.01 3.2 3.2 15 15 15 15WV 1,141 445 696 1.227% 2.472% 0.431% 0.18 0.18 0.5 0.5 0.5 0.5 0.5 0.5 1 1 0.5 1WY 1,607 1,121 486 0.000% 0.000% 0.000%Total 372,386 288,218 84,168 0.064% 0.033% 0.169% 0.01 0.01 0.04 0.6 0.54 0.7 2.4 2.3 2.4 40 36 40

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A64b. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.323% 0.211% 0.685% 0.254% 0.598% 0.040%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.441% 0.262% 1.389% 0.816% 0.437% 1.040%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 0.094% 0.000% 2.083% 4.865% 0.000% 8.901%CA 3,651 3,134 517 35,827,628 13,515,167 22,312,461 0.192% 0.064% 0.967% 1.426% 1.474% 1.396%CO 826 605 221 4,997,841 530,207 4,467,634 0.605% 0.165% 1.810% 0.024% 0.011% 0.026%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.249% 0.257% 0.000% 0.201% 1.403% 0.000%DE 318 315 3 698,987 417,587 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,509 1,483 26 17,495,514 15,249,472 2,246,042 0.331% 0.337% 0.000% 2.554% 2.930% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.110% 0.059% 0.862% 0.091% 0.044% 0.104%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,184 1,084 100 9,132,188 2,936,410 6,195,778 0.169% 0.185% 0.000% 0.015% 0.048% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.068% 0.070% 0.000% 0.003% 0.006% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 2.490% 1.087% 3.356% 7.913% 0.091% 8.607%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.139% 0.000% 0.847% 0.274% 0.000% 0.344%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.380% 0.203% 2.941% 2.191% 0.528% 2.617%ME 810 757 53 728,347 292,773 435,574 0.123% 0.132% 0.000% 0.030% 0.073% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.379% 0.193% 10.000% 0.974% 0.968% 0.990%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 848 788 60 757,949 365,280 392,669 0.118% 0.127% 0.000% 0.013% 0.026% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.127% 0.045% 1.439% 0.219% 0.010% 0.288%ND 210 183 27 562,397 257,172 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.259% 0.263% 0.000% 0.470% 1.002% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 0.572% 0.588% 0.000% 0.475% 1.357% 0.000%NM 727 688 39 1,698,980 1,432,432 266,548 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 338 317 21 973,592 283,701 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,524 1,288 236 4,894,939 1,044,337 3,850,602 0.459% 0.388% 0.847% 0.097% 0.425% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.051% 0.055% 0.000% 0.000% 0.001% 0.000%OK 730 518 212 3,123,687 664,833 2,458,854 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 500 454 46 2,553,197 1,698,877 854,320 0.200% 0.220% 0.000% 4.308% 6.475% 0.000%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 603 560 43 491,035 227,067 263,968 0.332% 0.357% 0.000% 0.967% 2.090% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.168% 0.170% 0.000% 0.428% 0.736% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.193% 1.018% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,195 45,942 4,253 226,851,469 86,314,890 140,536,579 0.179% 0.128% 0.729% 0.908% 1.016% 0.842%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A64c. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 3 1 2 0.082% 0.032% 0.387% 114,542 9,101 105,441 0.320% 0.067% 0.473%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 700 700 0 0.009% 0.044% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.084% 0.092% 0.000% 1,059 1,059 0 0.012% 0.036% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.161% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.056% 0.057% 0.000% 8,365 8,365 0 0.207% 0.356% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 7 5 2 0.014% 0.011% 0.047% 126,351 20,910 105,441 0.056% 0.024% 0.075%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A64d. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 5 1 4 0.137% 0.032% 0.774% 320,159 9,101 311,058 0.894% 0.067% 1.394%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.083% 0.086% 0.000% 2,800 2,800 0 0.103% 0.719% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 700 700 0 0.009% 0.044% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.084% 0.092% 0.000% 1,059 1,059 0 0.012% 0.036% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 0 1 0.042% 0.000% 0.719% 9,750 0 9,750 0.139% 0.000% 0.185%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.161% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.112% 0.113% 0.000% 16,493 16,493 0 0.408% 0.702% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 12 7 5 0.024% 0.015% 0.118% 352,646 31,838 320,808 0.155% 0.037% 0.228%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A64e. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 5 1 4 0.137% 0.032% 0.774% 320,159 9,101 311,058 0.894% 0.067% 1.394%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 1 0 0.083% 0.086% 0.000% 2,800 2,800 0 0.103% 0.719% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 700 700 0 0.009% 0.044% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 1 1 0 0.084% 0.092% 0.000% 1,059 1,059 0 0.012% 0.036% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 1 0 1 0.042% 0.000% 0.719% 9,750 0 9,750 0.139% 0.000% 0.185%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 1 1 0 0.072% 0.073% 0.000% 44 44 0 0.001% 0.002% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.161% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 2 2 0 0.112% 0.113% 0.000% 16,493 16,493 0 0.408% 0.702% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 13 8 5 0.026% 0.017% 0.118% 352,690 31,882 320,808 0.155% 0.037% 0.228%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A65. 2,4,5-Trichlorophenoxypropionic acid – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Source Water Type

Concentration or 

Threshold of 

Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 50 μg/L 29,954 0 0.000% 66,468,861 0 0.000%

	
 29,954 1 0.003% 66,468,861 240 0.000%

> 50 μg/L 2,933 0 0.000% 116,531,907 0 0.000%

	
 2,933 0 0.000% 116,531,907 0 0.000%

> 50 μg/L 32,887 0 0.000% 183,000,768 0 0.000%

	
 32,887 1 0.003% 183,000,768 240 0.000%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

Table A65a. 2,4,5-Trichlorophenoxypropionic acid – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of int

AK 73 39 34 0.000% 0.000% 0.000%AL 541 396 145 0.000% 0.000% 0.000%AR 1,588 1,357 231 0.000% 0.000% 0.000%AZ 6,802 5,383 1,419 0.118% 0.130% 0.070% 0.2 0.2 0.2 0.2 0.2 0.2 0.26 0.26 0.2 0.26 0.26 0.2CA 14,002 8,170 5,832 0.007% 0.012% 0.000% 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23CO 2,527 1,850 677 0.000% 0.000% 0.000%CT 1,599 1,013 586 0.438% 0.000% 1.195% 0.24 0.24 0.44 0.44 0.44 0.44 0.44 0.44DE 826 788 38 0.000% 0.000% 0.000%FL 2,388 2,321 67 0.461% 0.474% 0.000% 0.03 0.03 1 1 1 1 28 28GA 1,432 1,354 78 0.000% 0.000% 0.000%HIIA 1,731 1,601 130 0.000% 0.000% 0.000%ID 2,075 1,795 280 0.000% 0.000% 0.000%IL 4,005 3,463 542 0.000% 0.000% 0.000%IN 2,280 2,109 171 0.132% 0.095% 0.585% 0.1 0.1 0.1 0.1 0.15 0.1 0.2 0.2 0.1 0.2 0.2 0.1KY 1,750 441 1,309 0.457% 0.000% 0.611% 0.02 0.02 0.2 0.2 0.5 0.5 0.5 0.5MA 2,975 2,183 792 0.235% 0.183% 0.379% 0.1 0.1 0.1 0.2 0.45 0.2 2 2 0.2 2 2 0.2MD 2,494 1,699 795 0.922% 0.883% 1.006% 0.05 0.05 0.05 0.1 0.08 0.1 0.3 0.3 1.05 1.05 0.37 1.05ME 378 317 61 0.000% 0.000% 0.000%MI 6,587 6,294 293 0.000% 0.000% 0.000%MN 4,627 4,495 132 0.000% 0.000% 0.000%MO 5,802 4,983 819 0.000% 0.000% 0.000%MT 3,183 2,901 282 0.000% 0.000% 0.000%NC 13,959 12,727 1,232 0.043% 0.047% 0.000% 0.14 0.14 0.235 0.235 0.6 0.6 0.6 0.6ND 404 341 63 0.000% 0.000% 0.000%NE 2,220 2,143 77 0.045% 0.047% 0.000% 0.62 0.62 0.62 0.62 0.62 0.62 0.62 0.62NH 4,193 3,874 319 0.000% 0.000% 0.000%NJ 162 144 18 0.000% 0.000% 0.000%NM 4,349 4,102 247 0.023% 0.024% 0.000% 2 2 2 2 2 2 2 2NV 1,568 1,158 410 0.000% 0.000% 0.000%NY 2,891 2,177 714 0.069% 0.092% 0.000% 0.9 0.9 1.25 1.25 1.6 1.6 1.6 1.6OH 137 53 84 0.730% 0.000% 1.190% 5 5 5 5 5 5 5 5OKOR 2,056 1,574 482 0.000% 0.000% 0.000%RI 740 498 242 0.000% 0.000% 0.000%SC 3,304 2,893 411 0.303% 0.311% 0.243% 0.04 0.04 0.06 0.4 0.4 0.06 0.4 0.4 0.06 0.4 0.4 0.06SD 952 842 110 0.000% 0.000% 0.000%TN 56 12 44 0.000% 0.000% 0.000%TX 2,174 1,343 831 0.000% 0.000% 0.000%UT 7,085 5,897 1,188 0.000% 0.000% 0.000%VA 441 148 293 0.000% 0.000% 0.000%VT 1,298 1,104 194 0.154% 0.181% 0.000% 0.05 0.05 0.15 0.15 0.25 0.25 0.25 0.25WI 3,160 3,068 92 0.032% 0.033% 0.000% 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1WV 645 338 307 1.860% 2.663% 0.977% 0.01 0.01 0.01 0.01 0.01 0.01 0.1 0.1 0.5 0.5 0.1 0.5WY 1,254 941 313 0.000% 0.000% 0.000%Total 122,713 100,329 22,384 0.085% 0.071% 0.147% 0.01 0.01 0.01 0.2 0.2 0.2 1 1 0.5 28 28 5

erest are not necessarily MCL violations)

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A65b. 2,4,5-Trichlorophenoxypropionic acid – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 19 14 5 316,371 84,921 231,450 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 175 126 49 2,796,309 589,449 2,206,860 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AZ 918 870 48 6,045,047 2,674,456 3,370,591 0.545% 0.460% 2.083% 5.847% 1.998% 8.901%CA 1,580 1,258 322 33,370,087 12,021,293 21,348,794 0.063% 0.079% 0.000% 0.000% 0.000% 0.000%CO 814 595 219 4,993,697 526,788 4,466,909 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 655 617 38 2,595,127 261,240 2,333,887 0.611% 0.000% 10.526% 17.134% 0.000% 19.052%DE 254 251 3 624,615 343,215 281,400 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%FL 1,318 1,296 22 16,796,064 14,554,059 2,242,005 0.455% 0.463% 0.000% 15.506% 17.894% 0.000%GA 296 282 14 993,774 301,752 692,022 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%HIIA 1,055 1,022 33 2,542,641 1,434,015 1,108,626 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%ID 869 812 57 1,064,783 808,587 256,196 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IL 1,368 1,264 104 9,183,247 2,982,850 6,200,397 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IN 1,402 1,358 44 4,866,706 2,546,970 2,319,736 0.214% 0.147% 2.273% 5.417% 0.003% 11.360%KY 242 93 149 4,602,489 375,460 4,227,029 2.479% 0.000% 4.027% 8.257% 0.000% 8.990%MA 644 527 117 8,506,903 1,704,521 6,802,382 1.087% 0.759% 2.564% 1.472% 3.401% 0.989%MD 863 795 68 4,906,061 907,954 3,998,107 2.202% 1.509% 10.294% 4.634% 0.739% 5.519%ME 216 190 26 491,237 116,848 374,389 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MI 2,919 2,858 61 7,224,193 2,044,337 5,179,856 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MN 1,288 1,259 29 3,933,642 2,684,001 1,249,641 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MO 1,475 1,398 77 3,281,888 1,700,557 1,581,331 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%MT 846 786 60 757,811 365,142 392,669 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NC 2,365 2,228 137 6,885,177 1,733,551 5,151,626 0.254% 0.269% 0.000% 0.551% 2.190% 0.000%ND 209 182 27 559,198 253,973 305,225 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NE 739 728 11 1,454,673 678,193 776,480 0.135% 0.137% 0.000% 0.556% 1.192% 0.000%NH 1,237 1,196 41 945,754 395,955 549,799 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NJ 127 116 11 1,969,193 341,973 1,627,220 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NM 691 656 35 1,656,642 1,395,544 261,098 0.145% 0.152% 0.000% 0.490% 0.581% 0.000%NV 287 266 21 960,268 270,377 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,348 1,117 231 4,925,666 982,389 3,943,277 0.074% 0.090% 0.000% 0.034% 0.172% 0.000%OH 35 26 9 3,028,943 99,332 2,929,611 2.857% 0.000% 11.111% 7.115% 0.000% 7.357%OKOR 1,087 937 150 2,937,439 572,689 2,364,750 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 89 80 9 900,695 160,717 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 785 725 60 3,448,394 820,701 2,627,693 0.510% 0.414% 1.667% 1.873% 2.931% 1.543%SD 260 239 21 622,152 262,981 359,171 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 11 5 6 648,720 144,963 503,757 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TX 856 702 154 18,700,247 4,013,688 14,686,559 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%UT 426 389 37 2,500,671 1,667,485 833,186 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VA 173 63 110 2,380,983 26,904 2,354,079 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%VT 440 407 33 432,449 181,285 251,164 0.455% 0.491% 0.000% 0.117% 0.280% 0.000%WI 1,406 1,386 20 3,883,613 2,191,869 1,691,744 0.071% 0.072% 0.000% 0.360% 0.639% 0.000%WV 342 197 145 1,367,674 206,326 1,161,348 2.924% 4.569% 0.690% 0.465% 0.961% 0.377%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 32,887 29,954 2,933 183,000,768 66,468,861 116,531,907 0.237% 0.177% 0.852% 2.599% 4.241% 1.662%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table A65c. 2,4,5-Trichlorophenoxypropionic acid – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 50 μg/L

State

Number of Systems 

with At Least One Detection 

> 50 μg/L

Percent of Systems 

with At Least One Detection 

> 50 μg/L

Population Served by Systems 

with At Least One Detection 

> 50 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.076% 0.077% 0.000% 240 240 0 0.001% 0.002% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 1 1 0 0.003% 0.003% 0.000% 240 240 0 0.0001% 0.0004% 0.000%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	


Table A65d. 2,4,5-Trichlorophenoxypropionic acid – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A66. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 5 μg/L 46,177 157 0.340% 86,393,209 2,241,272 2.594%

	
 46,177 283 0.613% 86,393,209 4,817,431 5.576%

	
 46,177 490 1.061% 86,393,209 7,008,143 8.112%

> 0.5 μg/L 46,177 682 1.477% 86,393,209 8,714,465 10.087%

> 5 μg/L 4,255 38 0.893% 140,514,477 9,703,812 6.906%

	
 4,255 55 1.293% 140,514,477 11,131,487 7.922%

	
 4,255 93 2.186% 140,514,477 16,021,388 11.402%

> 0.5 μg/L 4,255 122 2.867% 140,514,477 17,384,229 12.372%

> 5 μg/L 50,432 195 0.387% 226,907,686 11,945,084 5.264%

	
 50,432 338 0.670% 226,907,686 15,948,918 7.029%

	
 50,432 583 1.156% 226,907,686 23,029,531 10.149%

> 0.5 μg/L 50,432 804 1.594% 226,907,686 26,098,694 11.502%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A66a. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,114 1,976 1,138 0.578% 0.759% 0.264% 0.44 0.5 0.44 0.705 0.78 0.51 0.9 0.9 0.71 1.3 1.3 0.71AL 1,002 672 330 22.056% 14.137% 38.182% 0.17 0.17 0.51 1.6 1 2.59 3.6 2.9 4 13.1 10.9 13.1AR 2,382 1,915 467 1.931% 2.402% 0.000% 0.16 0.16 1.53 1.53 4.78 4.78 6.1 6.1AZ 12,598 9,545 3,053 1.603% 1.697% 1.310% 0.18 0.18 0.5 1.5 2.5 0.73 4.2 4.3 1.15 6.3 6.3 1.3CA 114,988 61,095 53,893 20.308% 15.613% 25.630% 0.007 0.007 0.5 1.7 1.6 1.85 12 8.8 14.8 159 159 50CO 2,866 2,126 740 0.314% 0.376% 0.135% 0.09 0.09 0.87 0.6 0.6 0.87 1.2 1.2 0.87 1.2 1.2 0.87CT 6,934 6,042 892 5.076% 4.138% 11.435% 0.1 0.26 0.1 1.6 2 1.2 8.7 11.5 2.9 90.9 90.9 20.2DE 1,066 1,037 29 2.251% 2.314% 0.000% 0.51 0.51 0.785 0.785 74.1 74.1 93.6 93.6FL 4,173 4,105 68 2.876% 2.899% 1.471% 0.02 0.02 0.95 0.25 0.24 0.95 1.12 1.13 0.95 8.9 8.9 0.95GA 7,174 6,347 827 0.502% 0.425% 1.088% 0.5 0.5 0.55 2.4 2.2 14 15 6.9 18 18 8.4 18HI 1,792 1,689 103 0.000% 0.000% 0.000%IA 1,846 1,719 127 2.817% 2.909% 1.575% 0.5 0.5 1.1 1 1 1.55 3.2 3.65 2 10.4 10.4 2ID 3,769 3,308 461 6.129% 6.862% 0.868% 0.1 0.1 0.5 1.5 1.5 0.5 7.3 7.6 0.9 15.7 15.7 0.9IL 7,057 6,492 565 2.848% 3.096% 0.000% 0.4 0.4 1.2 1.2 2.96 2.96 7.34 7.34IN 4,630 4,320 310 1.663% 1.782% 0.000% 0.22 0.22 1.2 1.2 5.5 5.5 13 13KY 3,313 1,129 2,184 1.720% 4.074% 0.504% 0.001 0.1 0.001 1 1.4 0.5 4 4.1 1 8 8 1.7MA 16,225 12,259 3,966 4.222% 3.442% 6.631% 0.2 0.2 0.34 1.2 1 1.4 11 7.1 38 50 31.7 50MD 6,774 5,512 1,262 1.845% 1.941% 1.426% 0.5 0.5 0.5 1.2 1.3 0.75 4.3 5.4 4.1 22.4 19.2 22.4ME 3,692 3,377 315 0.948% 0.888% 1.587% 0.5 0.5 1 0.7 0.61 1.3 1.9 1.75 50 50 3 50MI 10,752 9,742 1,010 1.888% 2.084% 0.000% 0.4 0.4 0.7 0.7 3.2 3.2 6.5 6.5MN 8,596 7,346 1,250 3.327% 3.784% 0.640% 0.1 0.1 0.1 0.55 0.6 0.15 2.3 2.3 0.4 7.5 7.5 0.4MO 7,544 6,695 849 2.717% 3.032% 0.236% 0.5 0.5 0.6 1.1 1.1 1.17 4.7 4.7 1.74 44 44 1.74MT 4,480 3,946 534 0.201% 0.228% 0.000% 0.55 0.55 1.03 1.03 2.31 2.31 2.31 2.31NC 19,067 17,488 1,579 1.301% 1.395% 0.253% 0.5 0.5 1.04 1.4 1.4 2.05 4.91 4.91 2.9 16.8 16.8 2.9ND 558 417 141 1.971% 0.719% 5.674% 0.89 0.89 1.52 1.81 0.96 2.18 2.69 1.52 3.62 3.62 1.52 3.62NE 6,838 6,262 576 2.135% 2.332% 0.000% 0.15 0.15 1.1 1.1 4.4 4.4 7.9 7.9NH 9,589 9,111 478 1.126% 1.163% 0.418% 0.5 0.5 1 1 0.985 1.45 3.14 3.14 1.9 23.53 23.53 1.9NJ 20,355 18,567 1,788 3.468% 3.307% 5.145% 0.09 0.09 0.1 0.54 0.55 0.51 1.7 1.72 0.9 71.64 71.64 6.4NM 6,576 6,100 476 1.521% 1.541% 1.261% 0.1 0.1 0.2 1 1.055 0.4 4.55 4.6 0.5 18 18 0.5NV 3,255 2,586 669 3.164% 0.193% 14.649% 0.2 0.5 0.2 1.3 0.75 1.315 2.2 2 2.4 3.84 2 3.84NY 7,127 5,455 1,672 3.367% 2.511% 6.160% 0.3 0.3 0.5 1.55 1.4 1.7 9.35 10.5 8.4 23 23 15.2OH 8,846 7,688 1,158 1.933% 2.198% 0.173% 0.31 0.5 0.31 1.03 1.07 0.32 2.75 2.9 0.33 15.8 15.8 0.33OK 5,634 4,199 1,435 1.367% 1.834% 0.000% 0.3 0.3 1.2 1.2 43.9 43.9 58.7 58.7OR 2,327 1,682 645 0.430% 0.535% 0.155% 0.5 0.5 1.2 0.7 0.7 1.2 2.2 3.2 1.2 3.2 3.2 1.2RI 1,959 1,591 368 1.991% 2.263% 0.815% 0.3 0.3 0.5 0.8 0.9 0.6 3 3 0.6 4.6 4.6 0.6SC 4,340 3,801 539 1.290% 1.342% 0.928% 0.4 0.4 0.4 1.54 1.56 0.4 4.09 4.09 0.4 21.2 21.2 0.4SD 889 855 34 0.900% 0.936% 0.000% 0.53 0.53 0.68 0.68 0.93 0.93 0.93 0.93TN 2,945 1,165 1,780 0.441% 1.116% 0.000% 0.5 0.5 0.85 0.85 1.1 1.1 1.2 1.2TX 34,145 27,040 7,105 0.255% 0.288% 0.127% 0.5 0.5 0.5 1.02 1.065 0.8 7.3 7.4 1.1 21 21 1.1UT 8,995 7,564 1,431 0.278% 0.331% 0.000% 0.7 0.7 1 1 3.7 3.7 4.2 4.2VA 4,895 4,026 869 1.144% 1.341% 0.230% 0.5 0.5 0.6 1.2 1.25 0.6 3.1 3.1 0.6 4.6 4.6 0.6VT 4,345 3,954 391 0.230% 0.253% 0.000% 0.2 0.2 0.55 0.55 1.05 1.05 1.1 1.1WI 11,296 11,171 125 6.232% 6.266% 3.200% 0.01 0.01 0.11 0.725 0.735 0.18 13 13 0.23 38 38 0.23WV 1,190 492 698 6.639% 13.415% 1.862% 0.0018 0.0018 0.5 2.1 2 4.4 7 6.6 12.2 27 27 12.6WY 1,671 1,168 503 0.838% 1.199% 0.000% 0.5 0.5 2.6 2.6 5.6 5.6 5.8 5.8Total 403,609 304,776 98,833 7.323% 4.855% 14.934% 0.001 0.0018 0.001 1.5 1.3 1.8 10.5 7.5 14.2 159 159 50

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A66b. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 0.968% 0.844% 1.370% 0.507% 0.921% 0.250%AL 264 203 61 4,218,673 1,123,585 3,095,088 7.576% 5.911% 13.115% 19.683% 17.588% 20.444%AR 454 382 72 2,453,348 910,322 1,543,026 1.982% 2.356% 0.000% 1.335% 3.599% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 1.416% 1.187% 6.250% 23.105% 28.061% 18.994%CA 3,656 3,140 516 35,803,350 13,516,462 22,286,888 4.349% 3.599% 8.915% 40.706% 26.679% 49.213%CO 826 605 221 4,997,841 530,207 4,467,634 0.847% 0.992% 0.452% 0.020% 0.125% 0.008%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 3.728% 3.339% 15.385% 25.688% 11.664% 28.028%DE 319 316 3 699,172 417,772 281,400 1.254% 1.266% 0.000% 0.760% 1.272% 0.000%FL 1,509 1,483 26 17,495,514 15,249,472 2,246,042 0.994% 0.944% 3.846% 5.443% 6.182% 0.423%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.329% 0.234% 1.724% 0.684% 0.138% 0.831%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 1.231% 1.173% 3.030% 9.767% 11.388% 7.670%ID 935 878 57 1,093,666 837,604 256,062 1.390% 1.367% 1.754% 27.323% 13.469% 72.639%IL 1,430 1,326 104 9,217,581 3,017,184 6,200,397 1.049% 1.131% 0.000% 3.256% 9.947% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 1.357% 1.399% 0.000% 4.481% 8.523% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 6.639% 5.435% 7.383% 9.416% 6.441% 9.680%MA 718 600 118 8,557,325 1,749,901 6,807,424 7.521% 6.000% 15.254% 8.427% 18.811% 5.757%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 2.372% 2.130% 5.882% 3.039% 3.901% 2.818%ME 810 757 53 728,347 292,773 435,574 0.988% 0.925% 1.887% 6.049% 7.362% 5.166%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.841% 0.859% 0.000% 3.820% 13.823% 0.000%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 3.919% 3.737% 13.333% 23.430% 16.179% 40.902%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 0.988% 0.896% 2.597% 0.662% 0.963% 0.277%MT 848 788 60 757,949 365,280 392,669 0.472% 0.508% 0.000% 0.098% 0.203% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 1.986% 1.930% 2.878% 11.706% 5.189% 13.851%ND 210 183 27 562,397 257,172 305,225 0.952% 0.546% 3.704% 1.919% 1.543% 2.236%NE 771 760 11 1,462,181 685,701 776,480 2.205% 2.237% 0.000% 6.175% 13.168% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 2.067% 1.972% 4.878% 21.901% 5.569% 33.753%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 7.225% 6.980% 16.216% 27.093% 26.430% 27.450%NM 727 688 39 1,698,980 1,432,432 266,548 2.338% 2.180% 5.128% 38.532% 45.132% 3.064%NV 338 317 21 973,592 283,701 689,891 0.888% 0.631% 4.762% 34.564% 0.754% 48.467%NY 1,520 1,284 236 4,893,045 1,042,443 3,850,602 2.237% 2.103% 2.966% 11.222% 18.742% 9.186%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 1.080% 1.100% 0.800% 2.653% 1.783% 3.038%OK 730 518 212 3,123,687 664,833 2,458,854 1.781% 2.510% 0.000% 2.588% 12.157% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.365% 0.317% 0.658% 1.048% 5.325% 0.008%RI 145 136 9 913,884 173,906 739,978 5.517% 5.147% 11.111% 12.037% 3.498% 14.043%SC 819 757 62 3,356,831 732,879 2,623,952 2.198% 1.717% 8.065% 3.508% 4.149% 3.329%SD 245 233 12 266,416 194,218 72,198 0.816% 0.858% 0.000% 7.748% 10.628% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.855% 1.852% 0.000% 0.150% 0.582% 0.000%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.485% 0.499% 0.292% 3.987% 3.366% 4.352%UT 500 454 46 2,553,197 1,698,877 854,320 0.600% 0.661% 0.000% 0.815% 1.224% 0.000%VA 1,588 1,418 170 5,269,674 628,239 4,641,435 0.819% 0.776% 1.176% 2.612% 0.333% 2.920%VT 603 560 43 491,035 227,067 263,968 1.161% 1.250% 0.000% 1.765% 3.816% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 3.756% 3.685% 10.000% 14.656% 23.694% 2.113%WV 403 243 160 1,416,020 237,670 1,178,350 5.955% 8.230% 2.500% 5.995% 18.091% 3.556%WY 304 256 48 446,177 129,229 316,948 1.316% 1.563% 0.000% 0.072% 0.248% 0.000%Total 50,432 46,177 4,255 226,907,686 86,393,209 140,514,477 2.009% 1.867% 3.549% 13.018% 12.214% 13.512%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A66c. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 5 3 2 1.894% 1.478% 3.279% 291,136 48,827 242,309 6.901% 4.346% 7.829%AR 2 2 0 0.441% 0.524% 0.000% 19,740 19,740 0 0.805% 2.168% 0.000%AZ 2 2 0 0.189% 0.198% 0.000% 47,273 47,273 0 0.767% 1.691% 0.000%CA 65 43 22 1.778% 1.369% 4.264% 9,313,108 1,542,488 7,770,620 26.012% 11.412% 34.866%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 13 10 3 1.077% 0.856% 7.692% 483,768 5,757 478,011 17.764% 1.478% 20.481%DE 2 2 0 0.627% 0.633% 0.000% 4,510 4,510 0 0.645% 1.080% 0.000%FL 1 1 0 0.066% 0.067% 0.000% 32,680 32,680 0 0.187% 0.214% 0.000%GA 3 2 1 0.165% 0.117% 0.862% 48,011 1,150 46,861 0.641% 0.072% 0.795%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 1 1 0 0.095% 0.098% 0.000% 73,051 73,051 0 2.872% 5.092% 0.000%ID 3 3 0 0.321% 0.342% 0.000% 59,816 59,816 0 5.469% 7.141% 0.000%IL 4 4 0 0.280% 0.302% 0.000% 21,912 21,912 0 0.238% 0.726% 0.000%IN 5 5 0 0.339% 0.350% 0.000% 4,680 4,680 0 0.096% 0.182% 0.000%KY 1 1 0 0.415% 1.087% 0.000% 1,930 1,930 0 0.042% 0.514% 0.000%MA 11 7 4 1.532% 1.167% 3.390% 182,089 91,001 91,088 2.128% 5.200% 1.338%MD 4 3 1 0.380% 0.304% 1.471% 19,918 13,818 6,100 0.397% 1.348% 0.153%ME 1 0 1 0.123% 0.000% 1.887% 22,500 0 22,500 3.089% 0.000% 5.166%MI 1 1 0 0.034% 0.034% 0.000% 5,840 5,840 0 0.082% 0.295% 0.000%MN 3 3 0 0.190% 0.193% 0.000% 3,261 3,261 0 0.077% 0.108% 0.000%MO 3 3 0 0.212% 0.224% 0.000% 8,588 8,588 0 0.286% 0.508% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 6 6 0 0.253% 0.269% 0.000% 12,676 12,676 0 0.181% 0.731% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 4 4 0 0.519% 0.526% 0.000% 3,849 3,849 0 0.263% 0.561% 0.000%NH 4 4 0 0.318% 0.329% 0.000% 527 527 0 0.056% 0.132% 0.000%NJ 16 14 2 1.144% 1.029% 5.405% 848,739 95,828 752,911 10.954% 3.533% 14.951%NM 3 3 0 0.413% 0.436% 0.000% 10,025 10,025 0 0.590% 0.700% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 7 6 1 0.461% 0.467% 0.424% 288,775 17,825 270,950 5.902% 1.710% 7.037%OH 2 2 0 0.103% 0.110% 0.000% 348 348 0 0.003% 0.011% 0.000%OK 1 1 0 0.137% 0.193% 0.000% 2,086 2,086 0 0.067% 0.314% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 3 3 0 0.366% 0.396% 0.000% 5,874 5,874 0 0.175% 0.801% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 5 5 0 0.101% 0.108% 0.000% 6,911 6,911 0 0.028% 0.074% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 8 8 0 0.448% 0.454% 0.000% 70,219 70,219 0 1.738% 2.991% 0.000%WV 5 4 1 1.241% 1.646% 0.625% 51,144 28,682 22,462 3.612% 12.068% 1.906%WY 1 1 0 0.329% 0.391% 0.000% 100 100 0 0.022% 0.077% 0.000%Total 195 157 38 0.387% 0.340% 0.893% 11,945,084 2,241,272 9,703,812 5.264% 2.594% 6.906%

Percent of Population Served 

with At Least One Detection 

> 5 μg/L

State

Number of Systems 

with At Least One Detection 

> 5 μg/L

Percent of Systems 

with At Least One Detection 

> 5 μg/L

Population Served by Systems 

with At Least One Detection 

> 5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A66d. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 12 7 5 4.545% 3.448% 8.197% 721,003 148,629 572,374 17.091% 13.228% 18.493%AR 2 2 0 0.441% 0.524% 0.000% 19,740 19,740 0 0.805% 2.168% 0.000%AZ 5 5 0 0.472% 0.495% 0.000% 767,312 767,312 0 12.442% 27.440% 0.000%CA 86 59 27 2.352% 1.879% 5.233% 10,835,974 2,465,720 8,370,254 30.265% 18.242% 37.557%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 19 16 3 1.574% 1.370% 7.692% 484,017 6,006 478,011 17.773% 1.542% 20.481%DE 2 2 0 0.627% 0.633% 0.000% 4,510 4,510 0 0.645% 1.080% 0.000%FL 1 1 0 0.066% 0.067% 0.000% 32,680 32,680 0 0.187% 0.214% 0.000%GA 4 3 1 0.220% 0.176% 0.862% 48,079 1,218 46,861 0.642% 0.076% 0.795%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.189% 0.196% 0.000% 78,597 78,597 0 3.091% 5.479% 0.000%ID 5 5 0 0.535% 0.569% 0.000% 102,496 102,496 0 9.372% 12.237% 0.000%IL 10 10 0 0.699% 0.754% 0.000% 247,753 247,753 0 2.688% 8.211% 0.000%IN 7 7 0 0.475% 0.490% 0.000% 10,230 10,230 0 0.209% 0.398% 0.000%KY 3 3 0 1.245% 3.261% 0.000% 5,239 5,239 0 0.114% 1.396% 0.000%MA 21 13 8 2.925% 2.167% 6.780% 409,702 179,187 230,515 4.788% 10.240% 3.386%MD 11 9 2 1.044% 0.913% 2.941% 38,090 31,920 6,170 0.758% 3.113% 0.154%ME 2 1 1 0.247% 0.132% 1.887% 22,630 130 22,500 3.107% 0.044% 5.166%MI 8 8 0 0.269% 0.275% 0.000% 38,329 38,329 0 0.535% 1.938% 0.000%MN 7 7 0 0.442% 0.451% 0.000% 71,935 71,935 0 1.688% 2.389% 0.000%MO 5 5 0 0.353% 0.373% 0.000% 9,008 9,008 0 0.300% 0.533% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 10 9 1 0.422% 0.404% 0.719% 19,308 15,286 4,022 0.276% 0.882% 0.076%ND 1 0 1 0.476% 0.000% 3.704% 6,826 0 6,826 1.214% 0.000% 2.236%NE 8 8 0 1.038% 1.053% 0.000% 49,646 49,646 0 3.395% 7.240% 0.000%NH 9 9 0 0.715% 0.740% 0.000% 17,391 17,391 0 1.833% 4.359% 0.000%NJ 29 27 2 2.074% 1.984% 5.405% 942,587 189,676 752,911 12.165% 6.993% 14.951%NM 4 4 0 0.550% 0.581% 0.000% 59,050 59,050 0 3.476% 4.122% 0.000%NV 1 0 1 0.296% 0.000% 4.762% 334,370 0 334,370 34.344% 0.000% 48.467%NY 11 10 1 0.724% 0.779% 0.424% 294,565 23,615 270,950 6.020% 2.265% 7.037%OH 6 6 0 0.309% 0.330% 0.000% 7,725 7,725 0 0.076% 0.247% 0.000%OK 2 2 0 0.274% 0.386% 0.000% 2,444 2,444 0 0.078% 0.368% 0.000%OR 1 1 0 0.091% 0.106% 0.000% 65 65 0 0.002% 0.011% 0.000%RI 1 1 0 0.690% 0.735% 0.000% 1,200 1,200 0 0.131% 0.690% 0.000%SC 6 6 0 0.733% 0.793% 0.000% 6,415 6,415 0 0.191% 0.875% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 8 8 0 0.162% 0.174% 0.000% 10,121 10,121 0 0.040% 0.109% 0.000%UT 2 2 0 0.400% 0.441% 0.000% 19,500 19,500 0 0.764% 1.148% 0.000%VA 3 3 0 0.189% 0.212% 0.000% 786 786 0 0.015% 0.125% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 15 15 0 0.841% 0.850% 0.000% 161,431 161,431 0 3.996% 6.876% 0.000%WV 7 5 2 1.737% 2.058% 1.250% 68,039 32,316 35,723 4.805% 13.597% 3.032%WY 2 2 0 0.658% 0.781% 0.000% 125 125 0 0.028% 0.097% 0.000%Total 338 283 55 0.670% 0.613% 1.293% 15,948,918 4,817,431 11,131,487 7.029% 5.576% 7.922%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A66e. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 1 1 0 0.161% 0.211% 0.000% 500 500 0 0.082% 0.215% 0.000%AL 17 10 7 6.439% 4.926% 11.475% 759,097 165,389 593,708 17.994% 14.720% 19.182%AR 2 2 0 0.441% 0.524% 0.000% 19,740 19,740 0 0.805% 2.168% 0.000%AZ 10 9 1 0.944% 0.890% 2.083% 944,098 784,098 160,000 15.309% 28.041% 4.747%CA 132 93 39 3.611% 2.962% 7.558% 14,006,721 3,239,696 10,767,025 39.121% 23.969% 48.311%CO 1 1 0 0.121% 0.165% 0.000% 65 65 0 0.001% 0.012% 0.000%CT 37 31 6 3.065% 2.654% 15.385% 680,737 26,577 654,160 24.996% 6.824% 28.028%DE 3 3 0 0.940% 0.949% 0.000% 4,560 4,560 0 0.652% 1.092% 0.000%FL 3 3 0 0.199% 0.202% 0.000% 348,225 348,225 0 1.990% 2.284% 0.000%GA 4 3 1 0.220% 0.176% 0.862% 48,079 1,218 46,861 0.642% 0.076% 0.795%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 7 6 1 0.663% 0.587% 3.030% 243,985 158,957 85,028 9.594% 11.081% 7.670%ID 10 10 0 1.070% 1.139% 0.000% 105,471 105,471 0 9.644% 12.592% 0.000%IL 12 12 0 0.839% 0.905% 0.000% 258,591 258,591 0 2.805% 8.571% 0.000%IN 13 13 0 0.882% 0.909% 0.000% 104,920 104,920 0 2.145% 4.080% 0.000%KY 5 3 2 2.075% 3.261% 1.342% 65,951 5,239 60,712 1.433% 1.396% 1.436%MA 33 20 13 4.596% 3.333% 11.017% 513,503 209,423 304,080 6.001% 11.968% 4.467%MD 19 16 3 1.803% 1.623% 4.412% 46,172 38,081 8,091 0.919% 3.714% 0.202%ME 3 2 1 0.370% 0.264% 1.887% 22,755 255 22,500 3.124% 0.087% 5.166%MI 12 12 0 0.404% 0.412% 0.000% 45,373 45,373 0 0.634% 2.294% 0.000%MN 16 16 0 1.011% 1.031% 0.000% 194,561 194,561 0 4.567% 6.462% 0.000%MO 10 9 1 0.706% 0.672% 1.299% 13,629 12,455 1,174 0.454% 0.737% 0.089%MT 2 2 0 0.236% 0.254% 0.000% 235 235 0 0.031% 0.064% 0.000%NC 26 22 4 1.098% 0.987% 2.878% 773,293 44,038 729,255 11.050% 2.541% 13.851%ND 2 1 1 0.952% 0.546% 3.704% 10,793 3,967 6,826 1.919% 1.543% 2.236%NE 10 10 0 1.297% 1.316% 0.000% 53,516 53,516 0 3.660% 7.805% 0.000%NH 18 16 2 1.431% 1.315% 4.878% 207,032 21,459 185,573 21.821% 5.378% 33.753%NJ 49 46 3 3.505% 3.380% 8.108% 1,508,724 443,937 1,064,787 19.471% 16.366% 21.144%NM 7 7 0 0.963% 1.017% 0.000% 67,954 67,954 0 4.000% 4.744% 0.000%NV 2 1 1 0.592% 0.315% 4.762% 334,410 40 334,370 34.348% 0.014% 48.467%NY 16 14 2 1.053% 1.090% 0.847% 350,940 79,670 271,270 7.172% 7.643% 7.045%OH 14 14 0 0.720% 0.770% 0.000% 41,573 41,573 0 0.406% 1.327% 0.000%OK 7 7 0 0.959% 1.351% 0.000% 34,522 34,522 0 1.105% 5.193% 0.000%OR 2 1 1 0.182% 0.106% 0.658% 265 65 200 0.009% 0.011% 0.008%RI 4 4 0 2.759% 2.941% 0.000% 5,870 5,870 0 0.642% 3.375% 0.000%SC 9 9 0 1.099% 1.189% 0.000% 29,714 29,714 0 0.885% 4.054% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 1 0 0.285% 0.617% 0.000% 1,541 1,541 0 0.027% 0.105% 0.000%TX 16 15 1 0.323% 0.325% 0.292% 708,693 20,448 688,245 2.822% 0.220% 4.352%UT 3 3 0 0.600% 0.661% 0.000% 20,800 20,800 0 0.815% 1.224% 0.000%VA 9 9 0 0.567% 0.635% 0.000% 1,738 1,738 0 0.033% 0.277% 0.000%VT 3 3 0 0.498% 0.536% 0.000% 2,290 2,290 0 0.466% 1.009% 0.000%WI 20 20 0 1.121% 1.134% 0.000% 377,456 377,456 0 9.344% 16.077% 0.000%WV 10 7 3 2.481% 2.881% 1.875% 71,159 33,636 37,523 5.025% 14.152% 3.184%WY 3 3 0 0.987% 1.172% 0.000% 280 280 0 0.063% 0.217% 0.000%Total 583 490 93 1.156% 1.061% 2.186% 23,029,531 7,008,143 16,021,388 10.149% 8.112% 11.402%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A66f. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 6 4 2 0.968% 0.844% 1.370% 3,075 2,141 934 0.507% 0.921% 0.250%AL 20 12 8 7.576% 5.911% 13.115% 830,371 197,612 632,759 19.683% 17.588% 20.444%AR 3 3 0 0.661% 0.785% 0.000% 23,718 23,718 0 0.967% 2.605% 0.000%AZ 14 12 2 1.322% 1.187% 4.167% 1,124,883 784,658 340,225 18.241% 28.061% 10.094%CA 151 107 44 4.130% 3.408% 8.527% 14,484,081 3,569,344 10,914,737 40.455% 26.407% 48.974%CO 5 4 1 0.605% 0.661% 0.452% 646 290 356 0.013% 0.055% 0.008%CT 45 39 6 3.728% 3.339% 15.385% 699,584 45,424 654,160 25.688% 11.664% 28.028%DE 4 4 0 1.254% 1.266% 0.000% 5,316 5,316 0 0.760% 1.272% 0.000%FL 6 5 1 0.398% 0.337% 3.846% 434,952 425,452 9,500 2.486% 2.790% 0.423%GA 5 3 2 0.274% 0.176% 1.724% 50,199 1,218 48,981 0.671% 0.076% 0.831%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 12 11 1 1.136% 1.075% 3.030% 247,113 162,085 85,028 9.717% 11.299% 7.670%ID 12 11 1 1.283% 1.253% 1.754% 294,221 108,221 186,000 26.902% 12.920% 72.639%IL 14 14 0 0.979% 1.056% 0.000% 298,970 298,970 0 3.243% 9.909% 0.000%IN 20 20 0 1.357% 1.399% 0.000% 219,162 219,162 0 4.481% 8.523% 0.000%KY 9 5 4 3.734% 5.435% 2.685% 95,046 24,176 70,870 2.065% 6.441% 1.677%MA 47 31 16 6.546% 5.167% 13.559% 650,392 305,761 344,631 7.600% 17.473% 5.063%MD 25 21 4 2.372% 2.130% 5.882% 152,654 39,996 112,658 3.039% 3.901% 2.818%ME 8 7 1 0.988% 0.925% 1.887% 44,055 21,555 22,500 6.049% 7.362% 5.166%MI 19 19 0 0.639% 0.653% 0.000% 223,474 223,474 0 3.122% 11.299% 0.000%MN 25 25 0 1.580% 1.611% 0.000% 226,879 226,879 0 5.325% 7.535% 0.000%MO 14 12 2 0.988% 0.896% 2.597% 19,902 16,265 3,637 0.662% 0.963% 0.277%MT 4 4 0 0.472% 0.508% 0.000% 740 740 0 0.098% 0.203% 0.000%NC 42 38 4 1.774% 1.706% 2.878% 779,057 49,802 729,255 11.132% 2.874% 13.851%ND 2 1 1 0.952% 0.546% 3.704% 10,793 3,967 6,826 1.919% 1.543% 2.236%NE 14 14 0 1.816% 1.842% 0.000% 79,820 79,820 0 5.459% 11.641% 0.000%NH 24 22 2 1.908% 1.808% 4.878% 207,599 22,026 185,573 21.880% 5.520% 33.753%NJ 79 73 6 5.651% 5.364% 16.216% 1,987,792 605,404 1,382,388 25.654% 22.319% 27.450%NM 8 8 0 1.100% 1.163% 0.000% 149,117 149,117 0 8.777% 10.410% 0.000%NV 3 2 1 0.888% 0.631% 4.762% 336,510 2,140 334,370 34.564% 0.754% 48.467%NY 26 21 5 1.711% 1.636% 2.119% 484,035 130,627 353,408 9.892% 12.531% 9.178%OH 20 20 0 1.029% 1.100% 0.000% 55,869 55,869 0 0.546% 1.783% 0.000%OK 9 9 0 1.233% 1.737% 0.000% 37,044 37,044 0 1.186% 5.572% 0.000%OR 3 2 1 0.273% 0.212% 0.658% 30,765 30,565 200 1.046% 5.319% 0.008%RI 7 6 1 4.828% 4.412% 11.111% 109,891 5,975 103,916 12.025% 3.436% 14.043%SC 11 11 0 1.343% 1.453% 0.000% 30,353 30,353 0 0.904% 4.142% 0.000%SD 2 2 0 0.816% 0.858% 0.000% 20,641 20,641 0 7.748% 10.628% 0.000%TN 2 2 0 0.570% 1.235% 0.000% 6,835 6,835 0 0.120% 0.467% 0.000%TX 22 21 1 0.444% 0.456% 0.292% 1,000,446 312,201 688,245 3.984% 3.358% 4.352%UT 3 3 0 0.600% 0.661% 0.000% 20,800 20,800 0 0.815% 1.224% 0.000%VA 13 11 2 0.819% 0.776% 1.176% 137,640 2,091 135,549 2.612% 0.333% 2.920%VT 4 4 0 0.663% 0.714% 0.000% 3,790 3,790 0 0.772% 1.669% 0.000%WI 28 28 0 1.570% 1.587% 0.000% 408,984 408,984 0 10.125% 17.420% 0.000%WV 10 7 3 2.481% 2.881% 1.875% 71,159 33,636 37,523 5.025% 14.152% 3.184%WY 4 4 0 1.316% 1.563% 0.000% 321 321 0 0.072% 0.248% 0.000%Total 804 682 122 1.594% 1.477% 2.867% 26,098,694 8,714,465 17,384,229 11.502% 10.087% 12.372%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A67. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 30 μg/L 5,191 413 7.956% 23,338,623 1,240,188 5.314%	
 5,191 846 16.297% 23,338,623 5,684,077 24.355%

> 30 μg/L 730 35 4.795% 47,292,769 7,153,925 15.127%

	
 730 77 10.548% 47,292,769 13,809,436 29.200%> 30 μg/L 5,921 448 7.566% 70,631,392 8,394,113 11.884%	
 5,921 923 15.589% 70,631,392 19,493,513 27.599%

Ground Water

Surface Water

Combined Ground & 

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A67a. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 530 462 68 50.755% 57.143% 7.353% 0.1 0.1 0.2 0.3 0.3 0.2 1.2 1.2 0.2 11.64 11.64 0.2ALARAZ 1,077 830 247 86.815% 90.120% 75.709% 0.29 0.29 0.83 4.17 4.47 3.2 13.11 14.75 7.45 69 69 24.3CA 21,582 13,666 7,916 80.145% 80.214% 80.028% 0.00299 0.01 0.00299 8.44 8.82 7.76 30.74 32.98 25.37 425.37 425.37 244.77CO 1,166 971 195 60.034% 60.659% 56.923% 0.00075 0.00075 0.00149 10 11 7 46 46.26 32.83 268.65 268.65 160CT 1,505 1,383 122 66.844% 70.644% 23.770% 0.01 0.01 1 2.38 2.45 2.24 19.89 20 5.72 343.87 343.87 6.79DEFL 146 131 15 40.411% 41.221% 33.333% 0.00149 0.00149 0.44 1.19 1.19 0.74 6.41 6.41 1.64 21.94 21.94 1.64GAHIIA 46 46 0 95.652% 95.652% 0.000% 1.04 1.04 4.025 4.025 16.26 16.26 32.23 32.23ID 767 725 42 74.837% 74.345% 83.333% 0.00015 0.00015 0.00448 11.94 11.94 13.43 74.02 77.61 61.19 191.04 191.04 77.61IL 1,659 1,658 1 83.665% 83.655% 100.000% 1.4E-05 1.4E-05 2.53 0.38 0.38 2.53 3.28 3.28 2.53 18.35 18.35 2.53INKYMA 375 317 58 89.333% 91.798% 75.862% 0.14 0.14 2 24.77 25 22.115 83.58 86.56 45 183 183 101MD 98 81 17 76.531% 71.605% 100.000% 1.04 1.04 2.38 5.67 4.245 15.37 20.89 19.1 24.62 27.46 26.11 27.46ME 87 87 0 100.000% 100.000% 0.000% 0.02 0.02 44 44 140 140 469 469MIMN 463 463 0 72.138% 72.138% 0.000% 0.16 0.16 1 1 4.02 4.02 28.95 28.95MO 271 271 0 65.314% 65.314% 0.000% 1.3 1.3 4.17 4.17 8.5 8.5 23.28 23.28MT 88 81 7 87.500% 87.654% 85.714% 0.00448 0.00448 1.54 15 16 8.7 65 65 23 79 79 23NC 2,285 2,030 255 40.044% 44.483% 4.706% 0.4 0.4 0.44 17.31 17.77 3.13 76.71 76.71 4.17 298.5 298.5 5.67ND 180 164 16 100.000% 100.000% 100.000% 0.00001 0.00001 0.04 1.55 1.62 0.8 6.445 6.6 4.36 23.5 23.5 4.63NE 659 631 28 85.736% 85.261% 96.429% 0.29 0.29 9.55 32.68 33.805 14.47 74.02 76.56 30.44 252.23 252.23 37.91NHNJ 1,637 1,257 380 17.043% 18.218% 13.158% 0.00299 0.00299 0.02 1.04 1.13 0.31 35.37 41.79 19.4 380.59 380.59 25.37NM 855 808 47 90.760% 91.708% 74.468% 0.002 0.002 0.98 5.7 6 3.8 38 39.93 7.53 164.17 164.17 11NV 901 806 95 87.458% 87.841% 84.211% 0.00015 0.00015 0.00358 5.96 5.745 8.65 33 33 32 294.02 294.02 53.73NY 946 814 132 83.404% 86.855% 62.121% 0.0009 0.0009 0.01 2.71 2.98 1.335 11.34 11.7 9 150 150 16.86OH 5 0 5 40.000% 40.000% 1.49 1.49 1.49 1.49 1.49 1.49 1.49 1.49OKOR 1,013 805 208 59.131% 63.230% 43.269% 1.5E-06 1.5E-06 0.002 0.11 0.12 0.03 2.43 2.83 1 36 36 8.04RI 20 20 0 90.000% 90.000% 0.000% 5.85 5.85 14.79 14.79 42.35 42.35 89.01 89.01SC 1,808 1,662 146 3.319% 3.550% 0.685% 1.49 1.49 31.49 24.395 24.32 31.49 81.34 85.07 31.49 127.31 127.31 31.49SD 26 25 1 92.308% 92.000% 100.000% 8.5 8.5 16.1 15.55 15 16.1 24.17 24.17 16.1 28.35 28.35 16.1TNTX 549 506 43 66.120% 67.589% 48.837% 2 2 2.1 12.4 12.5 10.5 40.2 40.7 17.1 175.4 175.4 26.5UTVA 88 79 9 80.682% 84.810% 44.444% 0.14 0.14 1.2 21.6 23.1 1.6 41.34 43.13 2.4 67.76 67.76 2.4VT 175 164 11 68.571% 72.561% 9.091% 0.15 0.15 0.15 2.09 2.1 0.15 63.39 69.2 0.15 87 87 0.15WI 464 434 30 81.250% 80.184% 96.667% 0.03 0.03 0.23 2.23 2.08 4.17 6.86 6.56 7.16 104.47 104.47 7.91WV 50 38 12 2.000% 2.632% 0.000% 27.61 27.61 27.61 27.61 27.61 27.61 27.61 27.61WY 60 46 14 80.000% 78.261% 85.714% 0.00027 0.00027 0.6 6.5 11.9 2.85 24.2 27.5 4.3 35.2 35.2 5.5Total 41,581 31,461 10,120 70.542% 70.227% 71.522% 1.5E-06 1.5E-06 0.00149 6.8 6.57 7.31 32.83 35 25.07 469 469 244.77

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A67b. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 145 122 23 94,606 72,713 21,893 51.724% 59.836% 8.696% 42.400% 53.444% 5.719%ALARAZ 160 151 9 4,008,876 1,106,562 2,902,314 99.375% 99.338% 100.000% 99.994% 99.978% 100.000%CA 1,063 860 203 30,756,273 10,686,347 20,069,926 88.241% 89.302% 83.744% 92.263% 89.017% 93.991%CO 254 198 56 2,980,899 248,509 2,732,390 61.024% 62.121% 57.143% 84.537% 73.823% 85.511%CT 287 269 18 1,466,952 142,622 1,324,330 82.578% 84.758% 50.000% 27.917% 80.565% 22.247%DEFL 38 32 6 3,503,799 2,366,772 1,137,027 71.053% 68.750% 83.333% 87.091% 80.891% 99.998%GAHIIA 19 19 0 28,641 28,641 0 94.737% 94.737% 0.000% 98.129% 98.129% 0.000%ID 301 292 9 682,916 491,248 191,668 73.754% 73.288% 88.889% 89.333% 85.222% 99.870%IL 121 120 1 766,197 764,361 1,836 83.471% 83.333% 100.000% 93.472% 93.457% 100.000%INKYMA 38 33 5 118,830 21,517 97,313 68.421% 72.727% 40.000% 9.855% 21.476% 7.286%MD 19 18 1 328,268 323,168 5,100 73.684% 72.222% 100.000% 23.612% 22.406% 100.000%ME 27 27 0 5,703 5,703 0 100.000% 100.000% 0.000% 100.000% 100.000% 0.000%MIMN 112 112 0 730,523 730,523 0 87.500% 87.500% 0.000% 72.171% 72.171% 0.000%MO 80 80 0 88,067 88,067 0 60.000% 60.000% 0.000% 87.439% 87.439% 0.000%MT 43 38 5 20,290 17,127 3,163 83.721% 84.211% 80.000% 85.397% 93.577% 41.100%NC 385 328 57 3,636,665 359,874 3,276,791 35.065% 39.329% 10.526% 41.533% 23.731% 43.488%ND 171 155 16 533,303 237,120 296,183 100.000% 100.000% 100.000% 100.000% 100.000% 100.000%NE 171 169 2 302,725 277,273 25,452 62.573% 62.130% 100.000% 79.409% 77.519% 100.000%NHNJ 146 117 29 6,379,628 1,457,687 4,921,941 49.315% 54.701% 27.586% 34.390% 52.635% 28.987%NM 327 302 25 1,427,921 1,186,373 241,548 91.743% 94.371% 60.000% 96.200% 97.292% 90.835%NV 165 155 10 532,264 207,214 325,050 90.303% 92.258% 60.000% 97.133% 94.766% 98.643%NY 249 206 43 559,318 88,875 470,443 86.747% 92.718% 58.140% 91.436% 92.421% 91.250%OH 1 0 1 215,517 0 215,517 100.000% 0.000% 100.000% 100.000% 0.000% 100.000%OKOR 634 504 130 2,604,897 445,931 2,158,966 59.306% 64.484% 39.231% 60.548% 72.928% 57.991%RI 5 5 0 4,217 4,217 0 60.000% 60.000% 0.000% 47.830% 47.830% 0.000%SC 452 405 47 3,021,859 525,705 2,496,154 4.425% 4.691% 2.128% 0.824% 3.142% 0.336%SD 17 16 1 137,188 9,062 128,126 88.235% 87.500% 100.000% 99.632% 94.427% 100.000%TNTX 205 200 5 3,472,887 512,883 2,960,004 80.488% 80.000% 100.000% 96.791% 78.272% 100.000%UTVA 30 28 2 155,849 16,465 139,384 73.333% 75.000% 50.000% 11.486% 45.363% 7.484%VT 87 78 9 81,508 44,981 36,527 52.874% 57.692% 11.111% 36.928% 63.580% 4.107%WI 114 112 2 1,783,743 826,968 956,775 84.211% 83.929% 100.000% 96.214% 91.834% 100.000%WV 27 17 10 38,980 5,783 33,197 3.704% 5.882% 0.000% 0.231% 1.556% 0.000%WY 28 23 5 162,083 38,332 123,751 89.286% 91.304% 80.000% 78.455% 99.251% 72.014%Total 5,921 5,191 730 70,631,392 23,338,623 47,292,769 69.262% 71.528% 53.151% 77.256% 81.666% 75.079%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A67c. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ALARAZ 6 6 0 3.750% 3.974% 0.000% 16,123 16,123 0 0.402% 1.457% 0.000%CA 129 105 24 12.135% 12.209% 11.823% 7,453,544 602,391 6,851,153 24.234% 5.637% 34.136%CO 34 30 4 13.386% 15.152% 7.143% 120,267 100,917 19,350 4.035% 40.609% 0.708%CT 18 18 0 6.272% 6.691% 0.000% 3,273 3,273 0 0.223% 2.295% 0.000%DEFL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GAHIIA 1 1 0 5.263% 5.263% 0.000% 863 863 0 3.013% 3.013% 0.000%ID 28 27 1 9.302% 9.247% 11.111% 252,364 66,364 186,000 36.954% 13.509% 97.043%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%INKYMA 13 11 2 34.211% 33.333% 40.000% 9,977 2,887 7,090 8.396% 13.417% 7.286%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 14 14 0 51.852% 51.852% 0.000% 2,364 2,364 0 41.452% 41.452% 0.000%MIMN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 3 3 0 6.977% 7.895% 0.000% 472 472 0 2.326% 2.756% 0.000%NC 38 38 0 9.870% 11.585% 0.000% 18,284 18,284 0 0.503% 5.081% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 43 41 2 25.146% 24.260% 100.000% 178,042 152,590 25,452 58.813% 55.032% 100.000%NHNJ 9 9 0 6.164% 7.692% 0.000% 18,580 18,580 0 0.291% 1.275% 0.000%NM 33 33 0 10.092% 10.927% 0.000% 130,515 130,515 0 9.140% 11.001% 0.000%NV 17 16 1 10.303% 10.323% 10.000% 104,230 47,730 56,500 19.582% 23.034% 17.382%NY 4 4 0 1.606% 1.942% 0.000% 3,322 3,322 0 0.594% 3.738% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 2 2 0 0.315% 0.397% 0.000% 578 578 0 0.022% 0.130% 0.000%RI 3 3 0 60.000% 60.000% 0.000% 2,017 2,017 0 47.830% 47.830% 0.000%SC 7 6 1 1.549% 1.481% 2.128% 10,945 2,565 8,380 0.362% 0.488% 0.336%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TNTX 29 29 0 14.146% 14.500% 0.000% 40,152 40,152 0 1.156% 7.829% 0.000%UTVA 8 8 0 26.667% 28.571% 0.000% 3,422 3,422 0 2.196% 20.783% 0.000%VT 2 2 0 2.299% 2.564% 0.000% 489 489 0 0.600% 1.087% 0.000%WI 4 4 0 3.509% 3.571% 0.000% 23,973 23,973 0 1.344% 2.899% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 3 3 0 10.714% 13.043% 0.000% 317 317 0 0.196% 0.827% 0.000%

Total 448 413 35 7.566% 7.956% 4.795% 8,394,113 1,240,188 7,153,925 11.884% 5.314% 15.127%

Percent of Population Served 

with At Least One Detection 

> 30 μg/L

State

Number of Systems 

with At Least One Detection 

> 30 μg/L

Percent of Systems 

with At Least One Detection 

> 30 μg/L

Population Served by Systems 

with At Least One Detection 

> 30 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A67d. Uranium – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ALARAZ 28 27 1 17.500% 17.881% 11.111% 842,488 702,488 140,000 21.016% 63.484% 4.824%CA 299 246 53 28.128% 28.605% 26.108% 13,899,989 3,888,485 10,011,504 45.194% 36.387% 49.883%CO 56 50 6 22.047% 25.253% 10.714% 183,520 117,370 66,150 6.157% 47.230% 2.421%CT 37 37 0 12.892% 13.755% 0.000% 8,797 8,797 0 0.600% 6.168% 0.000%DEFL 1 1 0 2.632% 3.125% 0.000% 37,227 37,227 0 1.062% 1.573% 0.000%GAHIIA 1 1 0 5.263% 5.263% 0.000% 863 863 0 3.013% 3.013% 0.000%ID 56 55 1 18.605% 18.836% 11.111% 384,679 198,679 186,000 56.329% 40.444% 97.043%IL 2 2 0 1.653% 1.667% 0.000% 25,850 25,850 0 3.374% 3.382% 0.000%INKYMA 20 18 2 52.632% 54.545% 40.000% 10,456 3,366 7,090 8.799% 15.643% 7.286%MD 4 3 1 21.053% 16.667% 100.000% 17,305 12,205 5,100 5.272% 3.777% 100.000%ME 19 19 0 70.370% 70.370% 0.000% 2,606 2,606 0 45.695% 45.695% 0.000%MIMN 8 8 0 7.143% 7.143% 0.000% 25,428 25,428 0 3.481% 3.481% 0.000%MO 1 1 0 1.250% 1.250% 0.000% 11,224 11,224 0 12.745% 12.745% 0.000%MT 12 10 2 27.907% 26.316% 40.000% 5,436 4,506 930 26.792% 26.309% 29.402%NC 64 64 0 16.623% 19.512% 0.000% 23,297 23,297 0 0.641% 6.474% 0.000%ND 3 3 0 1.754% 1.935% 0.000% 2,684 2,684 0 0.503% 1.132% 0.000%NE 64 62 2 37.427% 36.686% 100.000% 205,629 180,177 25,452 67.926% 64.982% 100.000%NHNJ 15 13 2 10.274% 11.111% 6.897% 354,726 22,850 331,876 5.560% 1.568% 6.743%NM 55 55 0 16.820% 18.212% 0.000% 140,273 140,273 0 9.824% 11.824% 0.000%NV 35 33 2 21.212% 21.290% 20.000% 128,503 71,703 56,800 24.143% 34.603% 17.474%NY 13 12 1 5.221% 5.825% 2.326% 16,837 7,237 9,600 3.010% 8.143% 2.041%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OKOR 3 3 0 0.473% 0.595% 0.000% 723 723 0 0.028% 0.162% 0.000%RI 3 3 0 60.000% 60.000% 0.000% 2,017 2,017 0 47.830% 47.830% 0.000%SC 10 9 1 2.212% 2.222% 2.128% 11,975 3,595 8,380 0.396% 0.684% 0.336%SD 10 9 1 58.824% 56.250% 100.000% 133,595 5,469 128,126 97.381% 60.351% 100.000%TNTX 75 73 2 36.585% 36.500% 40.000% 2,955,865 123,437 2,832,428 85.113% 24.067% 95.690%UTVA 10 10 0 33.333% 35.714% 0.000% 4,172 4,172 0 2.677% 25.339% 0.000%VT 3 3 0 3.448% 3.846% 0.000% 909 909 0 1.115% 2.021% 0.000%WI 7 7 0 6.140% 6.250% 0.000% 52,475 52,475 0 2.942% 6.345% 0.000%WV 1 1 0 3.704% 5.882% 0.000% 90 90 0 0.231% 1.556% 0.000%WY 8 8 0 28.571% 34.783% 0.000% 3,875 3,875 0 2.391% 10.109% 0.000%Total 923 846 77 15.589% 16.297% 10.548% 19,493,513 5,684,077 13,809,436 27.599% 24.355% 29.200%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A68. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 2 μg/L 46,158 31 0.067% 86,057,502 334,543 0.389%	
 46,158 63 0.136% 86,057,502 427,229 0.496%

> 0.5 μg/L 46,158 113 0.245% 86,057,502 825,343 0.959%

> 2 μg/L 4,253 10 0.235% 140,406,921 147,536 0.105%	
 4,253 21 0.494% 140,406,921 468,912 0.334%

> 0.5 μg/L 4,253 33 0.776% 140,406,921 1,621,211 1.155%

> 2 μg/L 50,411 41 0.081% 226,464,423 482,079 0.213%	
 50,411 84 0.167% 226,464,423 896,141 0.396%

> 0.5 μg/L 50,411 146 0.290% 226,464,423 2,446,554 1.080%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A68a. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,107 1,969 1,138 0.000% 0.000% 0.000%AL 820 596 224 0.122% 0.168% 0.000% 0.54 0.54 0.54 0.54 0.54 0.54 0.54 0.54AR 2,393 1,926 467 0.084% 0.104% 0.000% 0.32 0.32 0.69 0.69 1.06 1.06 1.06 1.06AZ 11,697 9,539 2,158 0.274% 0.199% 0.602% 0.3 0.3 0.3 0.3 0.3 0.3 0.5 0.3 0.5 0.9 0.9 0.5CA 86,043 45,407 40,636 0.078% 0.024% 0.138% 0.5 0.6 0.5 1 0.73 1 1.5 1.6 1.5 5.6 5.6 2CO 2,892 2,151 741 0.000% 0.000% 0.000%CT 6,939 6,048 891 0.058% 0.050% 0.112% 0.52 0.52 1 0.635 0.57 1 1 0.7 1 1 0.7 1DE 1,048 1,018 30 0.095% 0.098% 0.000% 1.44 1.44 1.44 1.44 1.44 1.44 1.44 1.44FL 4,151 4,083 68 0.337% 0.343% 0.000% 0.17 0.17 0.88 0.88 4.6 4.6 4.98 4.98GA 7,174 6,347 827 0.070% 0.079% 0.000% 0.51 0.51 0.86 0.86 20 20 20 20HI 1,794 1,691 103 0.000% 0.000% 0.000%IA 1,995 1,846 149 0.301% 0.325% 0.000% 0.5 0.5 6.9 6.9 15 15 15 15ID 3,771 3,310 461 0.027% 0.030% 0.000% 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6IL 6,671 6,185 486 0.270% 0.291% 0.000% 0.5 0.5 0.92 0.92 4 4 6.2 6.2IN 4,621 4,311 310 0.216% 0.232% 0.000% 0.2 0.2 0.5 0.5 0.95 0.95 1.2 1.2KY 3,309 1,126 2,183 0.151% 0.000% 0.229% 0.5 0.5 0.5 0.5 6 6 6 6MA 16,249 12,259 3,990 0.080% 0.049% 0.175% 0.3 0.5 0.3 0.6 0.605 0.59 1.6 5 0.62 5 5 0.62MD 6,773 5,511 1,262 0.354% 0.435% 0.000% 0.5 0.5 1.3 1.3 3.3 3.3 3.8 3.8ME 3,689 3,374 315 0.054% 0.059% 0.000% 0.1 0.1 0.55 0.55 1 1 1 1MI 10,753 9,743 1,010 0.046% 0.021% 0.297% 0.5 0.5 0.5 0.6 0.7 0.6 0.9 0.9 0.8 0.9 0.9 0.8MN 8,583 7,336 1,247 0.489% 0.573% 0.000% 0.4 0.4 0.9 0.9 1.6 1.6 3.1 3.1MO 7,544 6,695 849 0.318% 0.239% 0.942% 0.5 0.5 0.57 1.09 1.015 1.12 1.88 1.88 2.48 2.64 2.64 2.48MT 4,455 3,916 539 0.022% 0.026% 0.000% 2.26 2.26 2.26 2.26 2.26 2.26 2.26 2.26NC 19,058 17,478 1,580 0.084% 0.092% 0.000% 0.5 0.5 0.8 0.8 2.41 2.41 2.57 2.57ND 551 416 135 0.181% 0.240% 0.000% 0.66 0.66 0.66 0.66 0.66 0.66 0.66 0.66NE 6,838 6,262 576 0.058% 0.064% 0.000% 0.43 0.43 0.89 0.89 1.6 1.6 1.6 1.6NH 9,581 9,103 478 0.021% 0.022% 0.000% 0.71 0.71 1.255 1.255 1.8 1.8 1.8 1.8NJ 20,361 18,574 1,787 0.157% 0.162% 0.112% 0.23 0.23 0.5 1.195 1.31 0.55 15.43 19.04 0.6 46.5 46.5 0.6NM 6,572 6,096 476 0.000% 0.000% 0.000%NV 3,209 2,577 632 0.000% 0.000% 0.000%NY 7,074 5,411 1,663 0.085% 0.074% 0.120% 0.5 0.5 0.5 0.5 0.5 0.5 13.6 13.6 0.5 13.6 13.6 0.5OH 8,844 7,683 1,161 0.294% 0.338% 0.000% 0.3 0.3 0.77 0.77 9.3 9.3 9.7 9.7OK 5,634 4,199 1,435 0.266% 0.357% 0.000% 0.6 0.6 3.11 3.11 6.3 6.3 20.6 20.6OR 2,325 1,683 642 0.000% 0.000% 0.000%RI 1,959 1,591 368 0.000% 0.000% 0.000%SC 4,342 3,803 539 0.230% 0.237% 0.186% 0.4 0.53 0.4 2.35 4.05 0.4 13.25 17 0.4 17 17 0.4SD 889 855 34 0.000% 0.000% 0.000%TN 2,944 1,166 1,778 0.102% 0.000% 0.169% 0.6 0.6 0.8 0.8 1.8 1.8 1.8 1.8TX 34,146 27,044 7,102 0.196% 0.111% 0.521% 0.5 0.5 0.6 1.6 0.95 2.1 3.4 6.05 3.4 20 20 3.6UT 8,988 7,557 1,431 0.078% 0.093% 0.000% 0.7 0.7 0.7 0.7 0.8 0.8 0.8 0.8VA 4,930 4,058 872 0.183% 0.123% 0.459% 0.6 0.8 0.6 1.1 1.2 1 4.7 4.7 1.8 4.7 4.7 1.8VT 4,348 3,955 393 0.046% 0.025% 0.254% 1.1 1.1 37.7 19.4 1.1 37.7 37.7 1.1 37.7 37.7 1.1 37.7WI 11,295 11,170 125 0.443% 0.448% 0.000% 0.01 0.01 0.5 0.5 0.9 0.9 3.59 3.59WV 1,141 445 696 2.016% 2.472% 1.724% 0.23 0.23 0.4 0.5 0.5 1.46 2.4 0.5 2.6 3 0.5 3WY 1,661 1,158 503 0.000% 0.000% 0.000%Total 373,161 288,671 84,490 0.147% 0.137% 0.183% 0.01 0.01 0.3 0.89 0.8 1 3.545 4.6 2.48 46.5 46.5 37.7

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A68b. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 619 473 146 606,053 232,450 373,603 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%AL 263 202 61 4,218,278 1,123,190 3,095,088 0.380% 0.495% 0.000% 0.011% 0.041% 0.000%AR 454 382 72 2,453,348 910,322 1,543,026 0.441% 0.524% 0.000% 0.062% 0.167% 0.000%AZ 1,059 1,011 48 6,166,873 2,796,282 3,370,591 1.605% 1.286% 8.333% 10.149% 1.477% 17.342%CA 3,651 3,134 517 35,828,298 13,515,837 22,312,461 0.219% 0.191% 0.387% 0.983% 0.074% 1.533%CO 827 606 221 4,998,841 531,207 4,467,634 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%CT 1,207 1,168 39 2,723,376 389,454 2,333,922 0.249% 0.171% 2.564% 1.224% 0.046% 1.420%DE 318 315 3 698,987 417,587 281,400 0.314% 0.317% 0.000% 0.109% 0.182% 0.000%FL 1,509 1,483 26 17,416,591 15,170,549 2,246,042 0.398% 0.405% 0.000% 1.986% 2.280% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 0.165% 0.176% 0.000% 0.030% 0.139% 0.000%HI 106 94 12 1,293,745 1,239,117 54,628 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%IA 1,056 1,023 33 2,543,141 1,434,515 1,108,626 0.284% 0.293% 0.000% 0.443% 0.785% 0.000%ID 935 878 57 1,093,666 837,604 256,062 0.107% 0.114% 0.000% 0.004% 0.005% 0.000%IL 1,401 1,301 100 8,824,185 2,758,065 6,066,120 0.642% 0.692% 0.000% 0.073% 0.233% 0.000%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 0.204% 0.210% 0.000% 0.217% 0.413% 0.000%KY 241 92 149 4,602,392 375,363 4,227,029 2.075% 0.000% 3.356% 2.411% 0.000% 2.626%MA 718 600 118 8,557,325 1,749,901 6,807,424 0.975% 0.667% 2.542% 1.446% 1.535% 1.423%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 0.474% 0.507% 0.000% 0.065% 0.316% 0.000%ME 810 757 53 728,347 292,773 435,574 0.247% 0.264% 0.000% 0.036% 0.089% 0.000%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 0.168% 0.069% 4.918% 2.468% 0.168% 3.346%MN 1,582 1,552 30 4,260,523 3,010,848 1,249,675 0.442% 0.451% 0.000% 5.316% 7.522% 0.000%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 1.553% 1.194% 7.792% 19.775% 12.281% 29.409%MT 848 788 60 757,949 365,280 392,669 0.118% 0.127% 0.000% 0.009% 0.019% 0.000%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 0.338% 0.359% 0.000% 0.225% 0.909% 0.000%ND 210 183 27 562,397 257,172 305,225 0.476% 0.546% 0.000% 0.252% 0.551% 0.000%NE 771 760 11 1,462,181 685,701 776,480 0.389% 0.395% 0.000% 0.232% 0.494% 0.000%NH 1,258 1,217 41 948,788 398,989 549,799 0.079% 0.082% 0.000% 0.003% 0.008% 0.000%NJ 1,398 1,361 37 7,748,495 2,712,549 5,035,946 0.572% 0.514% 2.703% 5.357% 5.809% 5.114%NM 727 688 39 1,698,980 1,432,432 266,548 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NV 338 317 21 973,592 283,701 689,891 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%NY 1,523 1,287 236 4,893,289 1,042,687 3,850,602 0.394% 0.311% 0.847% 0.096% 0.421% 0.008%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 0.206% 0.220% 0.000% 0.031% 0.100% 0.000%OK 730 518 212 3,123,687 664,833 2,458,854 0.548% 0.772% 0.000% 0.048% 0.226% 0.000%OR 1,097 945 152 2,940,119 574,689 2,365,430 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%RI 145 136 9 913,884 173,906 739,978 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%SC 819 757 62 3,356,831 732,879 2,623,952 0.488% 0.396% 1.613% 0.320% 0.137% 0.371%SD 245 233 12 266,416 194,218 72,198 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 0.855% 0.000% 1.587% 1.810% 0.000% 2.437%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 0.424% 0.304% 2.047% 0.657% 0.481% 0.760%UT 500 454 46 2,553,197 1,698,877 854,320 0.400% 0.441% 0.000% 0.042% 0.063% 0.000%VA 1,600 1,429 171 5,273,258 630,675 4,642,583 0.500% 0.280% 2.339% 1.713% 0.626% 1.860%VT 603 560 43 491,035 227,067 263,968 0.332% 0.179% 2.326% 0.296% 0.040% 0.517%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 0.392% 0.397% 0.000% 1.370% 2.358% 0.000%WV 403 243 160 1,416,020 237,670 1,178,350 3.474% 4.527% 1.875% 2.193% 1.018% 2.430%WY 304 256 48 446,177 129,229 316,948 0.000% 0.000% 0.000% 0.000% 0.000% 0.000%Total 50,411 46,158 4,253 226,464,423 86,057,502 140,406,921 0.411% 0.349% 1.082% 1.558% 1.388% 1.663%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A68c. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 1 1 0 0.027% 0.032% 0.000% 45 45 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 2 2 0 0.133% 0.135% 0.000% 197,826 197,826 0 1.136% 1.304% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 700 700 0 0.009% 0.044% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.189% 0.196% 0.000% 9,987 9,987 0 0.393% 0.696% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 3 3 0 0.214% 0.231% 0.000% 745 745 0 0.008% 0.027% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 1 0 1 0.415% 0.000% 0.671% 1,617 0 1,617 0.035% 0.000% 0.038%MA 1 1 0 0.139% 0.167% 0.000% 2,500 2,500 0 0.029% 0.143% 0.000%MD 1 1 0 0.095% 0.101% 0.000% 150 150 0 0.003% 0.015% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 2 2 0 0.126% 0.129% 0.000% 92,282 92,282 0 2.166% 3.065% 0.000%MO 2 1 1 0.141% 0.075% 1.299% 2,272 272 2,000 0.076% 0.016% 0.152%MT 1 1 0 0.118% 0.127% 0.000% 71 71 0 0.009% 0.019% 0.000%NC 2 2 0 0.084% 0.090% 0.000% 14,356 14,356 0 0.205% 0.828% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 2 2 0 0.143% 0.147% 0.000% 80 80 0 0.001% 0.003% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.162% 0.000%OH 2 2 0 0.103% 0.110% 0.000% 1,763 1,763 0 0.017% 0.056% 0.000%OK 1 1 0 0.137% 0.193% 0.000% 250 250 0 0.008% 0.038% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 1 0 0.122% 0.132% 0.000% 281 281 0 0.008% 0.038% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 11 5 6 0.222% 0.108% 1.754% 131,567 11,475 120,092 0.524% 0.123% 0.759%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 1 1 0 0.063% 0.070% 0.000% 50 50 0 0.001% 0.008% 0.000%VT 1 0 1 0.166% 0.000% 2.326% 1,365 0 1,365 0.278% 0.000% 0.517%WI 1 1 0 0.056% 0.057% 0.000% 25 25 0 0.001% 0.001% 0.000%WV 1 0 1 0.248% 0.000% 0.625% 22,462 0 22,462 1.586% 0.000% 1.906%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 41 31 10 0.081% 0.067% 0.235% 482,079 334,543 147,536 0.213% 0.389% 0.105%

Percent of Population Served 

with At Least One Detection 

> 2 μg/L

State

Number of Systems 

with At Least One Detection 

> 2 μg/L

Percent of Systems 

with At Least One Detection 

> 2 μg/L

Population Served by Systems 

with At Least One Detection 

> 2 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A68d. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 1 1 0 0.220% 0.262% 0.000% 357 357 0 0.015% 0.039% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 4 3 1 0.110% 0.096% 0.193% 208,600 8,600 200,000 0.582% 0.064% 0.896%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 1 0 1 0.083% 0.000% 2.564% 33,143 0 33,143 1.217% 0.000% 1.420%DE 1 1 0 0.314% 0.317% 0.000% 760 760 0 0.109% 0.182% 0.000%FL 2 2 0 0.133% 0.135% 0.000% 197,826 197,826 0 1.136% 1.304% 0.000%GA 1 1 0 0.055% 0.059% 0.000% 700 700 0 0.009% 0.044% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.189% 0.196% 0.000% 9,987 9,987 0 0.393% 0.696% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 5 5 0 0.357% 0.384% 0.000% 1,538 1,538 0 0.017% 0.056% 0.000%IN 1 1 0 0.068% 0.070% 0.000% 10,452 10,452 0 0.214% 0.406% 0.000%KY 2 0 2 0.830% 0.000% 1.342% 50,417 0 50,417 1.095% 0.000% 1.193%MA 2 2 0 0.279% 0.333% 0.000% 2,545 2,545 0 0.030% 0.145% 0.000%MD 4 4 0 0.380% 0.406% 0.000% 2,190 2,190 0 0.044% 0.214% 0.000%ME 1 1 0 0.123% 0.132% 0.000% 215 215 0 0.030% 0.073% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 2 2 0 0.126% 0.129% 0.000% 92,282 92,282 0 2.166% 3.065% 0.000%MO 12 8 4 0.847% 0.597% 5.195% 41,197 26,064 15,133 1.371% 1.543% 1.151%MT 1 1 0 0.118% 0.127% 0.000% 71 71 0 0.009% 0.019% 0.000%NC 4 4 0 0.169% 0.180% 0.000% 14,522 14,522 0 0.208% 0.838% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 2 2 0 0.259% 0.263% 0.000% 163 163 0 0.011% 0.024% 0.000%NH 1 1 0 0.079% 0.082% 0.000% 30 30 0 0.003% 0.008% 0.000%NJ 3 3 0 0.215% 0.220% 0.000% 20,080 20,080 0 0.259% 0.740% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.162% 0.000%OH 2 2 0 0.103% 0.110% 0.000% 1,763 1,763 0 0.017% 0.056% 0.000%OK 2 2 0 0.274% 0.386% 0.000% 390 390 0 0.012% 0.059% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 1 1 0 0.122% 0.132% 0.000% 281 281 0 0.008% 0.038% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 1 0 1 0.285% 0.000% 0.529% 2,900 0 2,900 0.051% 0.000% 0.069%TX 15 8 7 0.303% 0.174% 2.047% 152,355 32,163 120,192 0.607% 0.346% 0.760%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 5 3 2 0.313% 0.210% 1.170% 23,950 2,450 21,500 0.454% 0.388% 0.463%VT 2 1 1 0.332% 0.179% 2.326% 1,455 90 1,365 0.296% 0.040% 0.517%WI 1 1 0 0.056% 0.057% 0.000% 25 25 0 0.001% 0.001% 0.000%WV 2 0 2 0.496% 0.000% 1.250% 24,262 0 24,262 1.713% 0.000% 2.059%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 84 63 21 0.167% 0.136% 0.494% 896,141 427,229 468,912 0.396% 0.496% 0.334%

Percent of Population Served 

with At Least One Detection 

	


State

Number of Systems 

with At Least One Detection 

	


Percent of Systems 

with At Least One Detection 

	


Population Served by Systems 

with At Least One Detection 

	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A68e. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 1 1 0 0.380% 0.495% 0.000% 456 456 0 0.011% 0.041% 0.000%AR 1 1 0 0.220% 0.262% 0.000% 357 357 0 0.015% 0.039% 0.000%AZ 1 1 0 0.094% 0.099% 0.000% 66 66 0 0.001% 0.002% 0.000%CA 8 6 2 0.219% 0.191% 0.387% 352,030 10,030 342,000 0.983% 0.074% 1.533%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 3 2 1 0.249% 0.171% 2.564% 33,323 180 33,143 1.224% 0.046% 1.420%DE 1 1 0 0.314% 0.317% 0.000% 760 760 0 0.109% 0.182% 0.000%FL 3 3 0 0.199% 0.202% 0.000% 214,626 214,626 0 1.232% 1.415% 0.000%GA 3 3 0 0.165% 0.176% 0.000% 2,220 2,220 0 0.030% 0.139% 0.000%HI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IA 2 2 0 0.189% 0.196% 0.000% 9,987 9,987 0 0.393% 0.696% 0.000%ID 1 1 0 0.107% 0.114% 0.000% 40 40 0 0.004% 0.005% 0.000%IL 8 8 0 0.571% 0.615% 0.000% 3,439 3,439 0 0.039% 0.125% 0.000%IN 2 2 0 0.136% 0.140% 0.000% 10,562 10,562 0 0.216% 0.411% 0.000%KY 2 0 2 0.830% 0.000% 1.342% 50,417 0 50,417 1.095% 0.000% 1.193%MA 5 3 2 0.696% 0.500% 1.695% 72,530 26,464 46,066 0.848% 1.512% 0.677%MD 4 4 0 0.380% 0.406% 0.000% 2,190 2,190 0 0.044% 0.214% 0.000%ME 1 1 0 0.123% 0.132% 0.000% 215 215 0 0.030% 0.073% 0.000%MI 3 1 2 0.101% 0.034% 3.279% 173,554 3,173 170,381 2.425% 0.160% 3.289%MN 4 4 0 0.253% 0.258% 0.000% 221,734 221,734 0 5.204% 7.365% 0.000%MO 19 13 6 1.341% 0.970% 7.792% 503,012 116,439 386,573 16.744% 6.891% 29.409%MT 1 1 0 0.118% 0.127% 0.000% 71 71 0 0.009% 0.019% 0.000%NC 8 8 0 0.338% 0.359% 0.000% 15,754 15,754 0 0.225% 0.909% 0.000%ND 1 1 0 0.476% 0.546% 0.000% 1,417 1,417 0 0.252% 0.551% 0.000%NE 3 3 0 0.389% 0.395% 0.000% 3,389 3,389 0 0.232% 0.494% 0.000%NH 1 1 0 0.079% 0.082% 0.000% 30 30 0 0.003% 0.008% 0.000%NJ 5 4 1 0.358% 0.294% 2.703% 327,620 70,080 257,540 4.228% 2.584% 5.114%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 1 1 0 0.066% 0.078% 0.000% 1,685 1,685 0 0.034% 0.162% 0.000%OH 3 3 0 0.154% 0.165% 0.000% 3,103 3,103 0 0.030% 0.099% 0.000%OK 4 4 0 0.548% 0.772% 0.000% 1,501 1,501 0 0.048% 0.226% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 3 3 0 0.366% 0.396% 0.000% 1,006 1,006 0 0.030% 0.137% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 3 0 3 0.855% 0.000% 1.587% 102,900 0 102,900 1.810% 0.000% 2.437%TX 21 14 7 0.424% 0.304% 2.047% 164,899 44,707 120,192 0.657% 0.481% 0.760%UT 2 2 0 0.400% 0.441% 0.000% 1,070 1,070 0 0.042% 0.063% 0.000%VA 8 4 4 0.500% 0.280% 2.339% 90,322 3,950 86,372 1.713% 0.626% 1.860%VT 2 1 1 0.332% 0.179% 2.326% 1,455 90 1,365 0.296% 0.040% 0.517%WI 6 6 0 0.336% 0.340% 0.000% 54,552 54,552 0 1.350% 2.324% 0.000%WV 2 0 2 0.496% 0.000% 1.250% 24,262 0 24,262 1.713% 0.000% 2.059%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 146 113 33 0.290% 0.245% 0.776% 2,446,554 825,343 1,621,211 1.080% 0.959% 1.155%

Percent of Population Served 

with At Least One Detection 

> 0.5 μg/L

State

Number of Systems 

with At Least One Detection 

> 0.5 μg/L

Percent of Systems 

with At Least One Detection 

> 0.5 μg/L

Population Served by Systems 

with At Least One Detection 

> 0.5 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A69. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Source Water 

Type

Concentration 

or Threshold 

of Interest

Total # Systems 

Reporting

# Systems Exceeding 

Threshold of Interest

% Systems Exceeding Threshold of Interest

Total Pop. Served by 

Systems Reporting

Total Pop. Served by 

Systems Exceeding 

Threshold of Interest

% Pop. Served by 

Systems Exceeding 

Threshold of Interest

> 10,000 μg/L 43,726 0 0.000% 83,748,512 0 0.000%

*	
 43,726 0 0.000% 83,748,512 0 0.000%

*	
 43,726 9 0.021% 83,748,512 2,344 0.003%

> 10,000 μg/L 3,972 0 0.000% 134,323,023 0 0.000%

*	
 3,972 0 0.000% 134,323,023 0 0.000%

*	
 3,972 1 0.025% 134,323,023 1,785 0.001%

> 10,000 μg/L 47,698 0 0.000% 218,071,535 0 0.000%

*	
 47,698 0 0.000% 218,071,535 0 0.000%

*	
 47,698 10 0.021% 218,071,535 4,129 0.002%

Surface Water

Combined 

Ground & 

Ground Water

Surface Water
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A69a. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW Total GW SW

AK 3,385 2,220 1,165 6.204% 2.883% 12.532% 0.18 0.18 0.2 2.285 1.38 2.93 80.5 4.98 167 506 73 506AL 904 669 235 12.168% 14.499% 5.532% 0.51 0.52 0.51 1.385 1.51 0.7 15.575 16.27 2.9 194.9 194.9 20AR 2,393 1,926 467 6.143% 7.113% 2.141% 0.21 0.21 0.5 1.26 1.26 1.465 6.49 6.53 3.51 34.6 34.6 3.93AZ 11,736 9,562 2,174 3.391% 3.639% 2.300% 0.5 0.5 0.5 2 2 1.5 10 9.1 25 480 191 480CA 83,594 43,873 39,721 0.206% 0.157% 0.259% 0.25 0.25 0.5 1.2 1.4 1 8.3 6.9 13.2 79 62 79CO 2,975 2,213 762 5.849% 6.055% 5.249% 0.06 0.06 0.3 1.7 1.4 2.5 10.5 10 11.5 2800 2800 17.9CT 146 144 2 2.055% 2.083% 0.000% 0.78 0.78 2.2 2.2 9.1 9.1 9.1 9.1DE 1,056 1,026 30 2.652% 2.729% 0.000% 0.56 0.56 3.44 3.44 83.5 83.5 259 259FL 4,241 4,173 68 4.150% 4.218% 0.000% 0.08 0.08 1.45 1.45 8.4 8.4 1300 1300GA 7,172 6,346 826 6.762% 7.501% 1.090% 0.5 0.5 0.5 1.6 1.6 1.7 6 6 5.6 58 58 5.6HIIA 2,217 2,058 159 11.412% 11.224% 13.836% 0.1 0.1 0.5 1 1 1 6.1 6.1 4.3 4000 4000 37ID 3,741 3,280 461 0.508% 0.549% 0.217% 0.3 0.3 11.6 1.1 1.1 11.6 600 600 11.6 2100 2100 11.6IL 7,194 6,601 593 7.034% 7.514% 1.686% 0.5 0.5 0.6 1.175 1.185 0.835 5.4 5.5 1.845 800 800 2.29IN 4,622 4,312 310 1.125% 1.020% 2.581% 0.5 0.5 0.55 1.45 1.3 2.095 6.1 6.1 13.8 43 43 13.8KY 2,988 1,000 1,988 2.644% 2.000% 2.968% 0.002 0.3 0.002 1 2.55 0.8 11 20.75 4 66 66 20.7MA 16,249 12,259 3,990 0.769% 0.710% 0.952% 0.5 0.5 0.52 1.56 1.5 1.825 6.6 5.6 15.6 53 30 53MD 6,763 5,509 1,254 2.455% 2.868% 0.638% 0.3 0.5 0.3 2.95 3.1 1.55 12.8 13 5.6 39.9 39.9 5.6ME 3,362 3,079 283 0.684% 0.390% 3.887% 0.9 1 0.9 2.2 1.95 2.8 9.2 10.2 6.7 16.5 16.5 9.2MI 19,359 17,522 1,837 1.612% 0.965% 7.784% 0.06 0.06 0.5 1 1 0.8 5.5 6.4 4.8 800 800 23.2MN 8,693 7,423 1,270 7.765% 6.588% 14.646% 0.2 0.2 0.2 0.7 0.7 0.8 3.2 3.3 3 199 199 61MO 7,543 6,694 849 3.301% 3.257% 3.651% 0.5 0.5 0.5 1.89 2.1 1 10.3 11.1 2 239 239 18.6MT 4,494 3,952 542 1.090% 0.987% 1.845% 0.44 0.44 1.1 4 4 4.95 27 30 7.3 2400 2400 7.6NC 19,072 17,491 1,581 8.054% 8.684% 1.075% 0.5 0.5 0.57 2.2 2.2 1.3 14.8 15 5.3 2220 2220 15.2ND 570 434 136 9.123% 10.599% 4.412% 0.5 0.5 0.61 1.02 1.075 0.79 5.77 9.8 1.2 242 242 1.2NE 6,838 6,262 576 0.775% 0.671% 1.910% 0.33 0.33 0.34 1.3 1.765 0.75 11.6 12.8 1.76 30.1 30.1 2.33NH 9,584 9,106 478 0.355% 0.373% 0.000% 0.5 0.5 1.765 1.765 19.3 19.3 71 71NJ 19,767 18,015 1,752 0.890% 0.916% 0.628% 0.12 0.12 0.3 1.35 1.25 1.9 6.8 6.6 11.4 300 300 25NM 6,547 6,071 476 1.466% 1.417% 2.101% 0.14 0.14 0.2 1.2 1.35 0.93 7.4 8.07 2.385 104 104 2.7NV 3,139 2,508 631 0.828% 0.797% 0.951% 0.74 0.74 0.9 2.7 2.7 4.2 36.9 60.3 10.8 1400 1400 10.8NY 25 22 3 24.000% 27.273% 0.000% 0.5 0.5 1.31 1.31 7.6 7.6 7.6 7.6OH 8,832 7,676 1,156 2.638% 2.619% 2.768% 0.01 0.01 0.5 1.7 2.1 0.9 16.6 22 2.3 327 327 6.8OK 5,636 4,200 1,436 4.418% 4.500% 4.178% 0.34 0.5 0.34 1.7 1.9 1.46 12.4 14.6 7.51 117.9 117.9 38.5OR 2,344 1,689 655 1.280% 0.414% 3.511% 0.6 1 0.6 2 2.9 1.4 305 600 10 1860 600 1860RI 1,953 1,585 368 0.819% 0.505% 2.174% 0.7 0.7 0.95 5.3 3.8 6.925 14 14 35.1 35.1 14 35.1SC 4,333 3,800 533 40.157% 40.289% 39.212% 0.3 0.3 1 1 1 1 1 1 1 600 600 6.06SD 886 852 34 1.580% 1.643% 0.000% 1.28 1.28 2.415 2.415 3.7 3.7 5.25 5.25TN 2,945 1,164 1,781 0.340% 0.601% 0.168% 0.55 0.76 0.55 1.05 1.1 1 3.85 5.2 2.5 5.2 5.2 2.5TX 34,162 27,058 7,104 0.266% 0.288% 0.183% 1.88 1.88 2.23 4.85 5.415 3.55 15.76 19.54 5.42 318.56 318.56 14.52UT 8,981 7,550 1,431 0.557% 0.503% 0.839% 0.3 0.3 0.7 1.8 1.8 4.3 68.3 69.5 15.3 490 140 490VA 4,918 4,045 873 4.107% 4.598% 1.833% 0.5 0.5 0.5 3.25 3.2 3.75 19 18 28 320 320 47VT 3,995 3,633 362 0.125% 0.138% 0.000% 0.2 0.2 3.1 3.1 29.6 29.6 29.6 29.6WI 11,300 11,176 124 1.522% 1.539% 0.000% 0.02 0.02 0.88 0.88 4.8 4.8 1420 1420WV 1,143 444 699 2.800% 4.730% 1.574% 0.25 0.25 0.5 0.82 0.6 1.3 4 3.11 4 10.1 4.1 10.1WY 1,669 1,165 504 2.217% 2.747% 0.992% 0.5 0.5 0.56 1.7 2.05 1.03 13 13 2.3 41 41 2.3Total 363,466 281,787 81,679 2.551% 2.811% 1.654% 0.002 0.01 0.002 1.1 1.1 1 8.1 8.1 8.3 4000 4000 1860

Median Detect 

Concentration (μg/L)

Maximum Detect 

Concentration (μg/L)

90th Percentile Detect 

Concentration (μg/L) State Number of Records Percent of Samples with Detections Minimum Detect Concentration (μg/L)
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A69b. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 620 474 146 606,193 232,590 373,603 11.129% 6.118% 27.397% 7.842% 6.903% 8.427%AL 266 204 62 4,230,338 1,124,693 3,105,645 21.053% 23.529% 12.903% 18.185% 27.024% 14.984%AR 454 382 72 2,453,348 910,322 1,543,026 11.233% 12.565% 4.167% 4.089% 9.243% 1.049%AZ 1,058 1,010 48 6,166,773 2,796,182 3,370,591 12.382% 11.584% 29.167% 32.122% 42.836% 23.233%CA 3,626 3,111 515 35,825,523 13,513,182 22,312,341 2.206% 1.446% 6.796% 31.037% 7.723% 45.156%CO 829 608 221 5,000,031 532,397 4,467,634 10.374% 11.513% 7.240% 4.132% 23.437% 1.831%CT 110 109 1 30,258 23,638 6,620 1.818% 1.835% 0.000% 0.687% 0.880% 0.000%DE 318 315 3 698,987 417,587 281,400 5.660% 5.714% 0.000% 18.897% 31.631% 0.000%FL 1,520 1,494 26 17,504,412 15,258,370 2,246,042 5.000% 5.087% 0.000% 4.071% 4.670% 0.000%GA 1,822 1,706 116 7,485,298 1,592,517 5,892,781 8.123% 8.499% 2.586% 6.656% 24.580% 1.812%HIIA 1,057 1,024 33 2,543,315 1,434,689 1,108,626 14.191% 13.574% 33.333% 16.461% 17.157% 15.559%ID 935 878 57 1,093,666 837,604 256,062 1.070% 1.025% 1.754% 4.892% 6.325% 0.205%IL 1,428 1,324 104 9,214,706 3,014,309 6,200,397 10.784% 11.329% 3.846% 5.133% 15.334% 0.174%IN 1,474 1,430 44 4,891,221 2,571,485 2,319,736 1.696% 1.608% 4.545% 3.380% 6.390% 0.042%KY 241 92 149 4,602,392 375,363 4,227,029 20.332% 14.130% 24.161% 21.628% 9.444% 22.710%MA 718 600 118 8,557,325 1,749,901 6,807,424 8.078% 6.833% 14.407% 6.905% 14.424% 4.972%MD 1,054 986 68 5,023,402 1,025,295 3,998,107 6.072% 6.085% 5.882% 36.067% 7.908% 43.288%ME 807 754 53 728,215 292,641 435,574 1.611% 1.459% 3.774% 19.511% 1.141% 31.853%MI 2,972 2,911 61 7,157,738 1,977,882 5,179,856 2.927% 2.267% 34.426% 57.568% 22.311% 71.030%MN 1,584 1,554 30 4,260,894 3,011,219 1,249,675 17.992% 16.988% 70.000% 48.687% 45.335% 56.762%MO 1,417 1,340 77 3,004,094 1,689,633 1,314,461 10.092% 9.254% 24.675% 13.389% 18.111% 7.320%MT 848 788 60 757,949 365,280 392,669 2.123% 1.650% 8.333% 4.375% 4.781% 3.998%NC 2,367 2,228 139 6,998,123 1,732,957 5,265,166 20.110% 20.826% 8.633% 24.297% 37.518% 19.946%ND 210 183 27 562,397 257,172 305,225 19.048% 19.126% 18.519% 6.209% 11.612% 1.656%NE 771 760 11 1,462,181 685,701 776,480 4.280% 3.816% 36.364% 4.928% 8.617% 1.670%NH 1,258 1,217 41 948,788 398,989 549,799 1.908% 1.972% 0.000% 0.633% 1.504% 0.000%NJ 1,392 1,355 37 7,746,465 2,710,519 5,035,946 6.250% 6.125% 10.811% 17.118% 20.126% 15.499%NM 724 685 39 1,690,690 1,424,142 266,548 7.320% 7.007% 12.821% 43.697% 50.692% 6.323%NV 338 317 21 973,592 283,701 689,891 4.438% 3.785% 14.286% 27.034% 5.191% 36.016%NY 12 10 2 8,865 4,945 3,920 41.667% 50.000% 0.000% 5.753% 10.313% 0.000%OH 1,944 1,819 125 10,227,597 3,132,660 7,094,937 5.350% 4.728% 14.400% 20.719% 2.928% 28.575%OK 730 518 212 3,123,687 664,833 2,458,854 10.685% 11.004% 9.906% 3.884% 9.590% 2.341%OR 1,097 945 152 2,940,119 574,689 2,365,430 1.550% 0.741% 6.579% 1.317% 0.602% 1.490%RI 145 136 9 913,884 173,906 739,978 6.207% 4.412% 33.333% 23.796% 41.287% 19.685%SC 819 757 62 3,356,831 732,879 2,623,952 72.772% 71.731% 85.484% 93.601% 80.116% 97.367%SD 245 233 12 266,416 194,218 72,198 2.041% 2.146% 0.000% 2.048% 2.809% 0.000%TN 351 162 189 5,685,258 1,462,502 4,222,756 1.994% 2.469% 1.587% 2.278% 0.909% 2.752%TX 4,951 4,609 342 25,111,902 9,297,171 15,814,731 1.232% 1.085% 3.216% 1.412% 1.701% 1.243%UT 500 454 46 2,553,197 1,698,877 854,320 3.200% 3.084% 4.348% 8.735% 3.781% 18.586%VA 1,596 1,425 171 5,272,971 630,388 4,642,583 5.639% 5.684% 5.263% 4.252% 12.464% 3.137%VT 600 557 43 490,811 226,843 263,968 0.667% 0.718% 0.000% 0.273% 0.591% 0.000%WI 1,784 1,764 20 4,039,526 2,347,782 1,691,744 4.484% 4.535% 0.000% 11.234% 19.330% 0.000%WV 402 242 160 1,415,980 237,630 1,178,350 6.468% 6.612% 6.250% 3.297% 3.387% 3.279%WY 304 256 48 446,177 129,229 316,948 7.237% 6.641% 10.417% 11.470% 7.933% 12.912%Total 47,698 43,726 3,972 218,071,535 83,748,512 134,323,023 7.592% 7.275% 11.078% 17.480% 13.222% 20.134%

Percent of Systems 

with At Least One Detection

Total Population Served by Systems 

Reporting

Percent of Population Served 

with At Least One Detection State Total Number of Systems Reporting
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A69c. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

> 10,000 μg/L

State

Number of Systems 

with At Least One Detection 

> 10,000 μg/L

Percent of Systems 

with At Least One Detection 

> 10,000 μg/L

Population Served by Systems 

with At Least One Detection 

> 10,000 μg/L
Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A69d. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ID 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%

Percent of Population Served 

with At Least One Detection 

*	


State

Number of Systems 

with At Least One Detection 

*	


Percent of Systems 

with At Least One Detection 

*	


Population Served by Systems 

with At Least One Detection 

*	

Appendix A - Analysis of Occ. Data from the 2nd Six-Year Review

Table A69e. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Total GW SW Total GW SW Total GW SW Total GW SW

AK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AR 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%AZ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%CO 1 1 0 0.121% 0.164% 0.000% 320 320 0 0.006% 0.060% 0.000%CT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%DE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%FL 1 1 0 0.066% 0.067% 0.000% 100 100 0 0.001% 0.001% 0.000%GA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%HIIA 1 1 0 0.095% 0.098% 0.000% 1,074 1,074 0 0.042% 0.075% 0.000%ID 1 1 0 0.107% 0.114% 0.000% 200 200 0 0.018% 0.024% 0.000%IL 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%IN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%KY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%ME 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MO 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%MT 1 1 0 0.118% 0.127% 0.000% 165 165 0 0.022% 0.045% 0.000%NC 2 2 0 0.084% 0.090% 0.000% 317 317 0 0.005% 0.018% 0.000%ND 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NE 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NJ 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NM 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%NV 1 1 0 0.296% 0.315% 0.000% 100 100 0 0.010% 0.035% 0.000%NY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OH 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OK 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%OR 1 0 1 0.091% 0.000% 0.658% 1,785 0 1,785 0.061% 0.000% 0.075%RI 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SC 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%SD 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TN 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%TX 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%UT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VA 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%VT 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WI 1 1 0 0.056% 0.057% 0.000% 68 68 0 0.002% 0.003% 0.000%WV 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%WY 0 0 0 0.000% 0.000% 0.000% 0 0 0 0.000% 0.000% 0.000%Total 10 9 1 0.021% 0.021% 0.025% 4,129 2,344 1,785 0.002% 0.003% 0.001%

Percent of Population Served 

with At Least One Detection 

*	


State

Number of Systems 

with At Least One Detection 

*	


Percent of Systems 

with At Least One Detection 

*	


Population Served by Systems 

with At Least One Detection 

*	

Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B1. Benzene - Summary of the Stage 2 Analyses

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 46,177 9 9 9 0.019% 0.019% 0.019%

	
 46,177 15 13 13 | +| +|

	
 46,177 67 55 49 0.145% 0.119% 0.106%

> 0.5 μg/L 46,177 }' 114 90 | '| 0.195%

> 5 μg/L '*+ 1 1 1 | | |

	
 '*+ 1 1 1 | | |

	
 '*+ 3 3 3 0.070% 0.070% 0.070%

> 0.5 μg/L '*+ 37 9 5 +}=| | 0.117%

> 5 μg/L 50,435 10 10 10 | | |

	
 50,435 16 14 14 | +| +|

	
 50,435 70 +  0.139% 0.115% 0.103%

> 0.5 μg/L 50,435 301  95 0.597% ''| ++|

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B1. Benzene - Summary of the Stage 2 Analyses

Revised September 2010

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+}*=*+ '* '* '* 0.016% 0.016% 0.016%

+}*=*+ *+ 109,663 109,663 +| | |

+}*=*+ 169,570 '+*}== '*= 0.196% | 0.171%

+}*=*+ 1,364,591 =+*+ +*++} 1.579% '}| |

140,551,755 50 50 50 0.00004% 0.00004% 0.00004%

140,551,755 50 50 50 0.00004% 0.00004% 0.00004%

140,551,755 *} *} *} +| +| +|

140,551,755 *+*= +}* * | 0.061% 0.015%}*='*= '* '* '* 0.006% 0.006% 0.006%

}*='*= *+ 109,713 109,713 0.049% '+| '+|

}*='*= +*= =*' +*' 0.079% 0.070% 0.070%

}*='*= +*}+*++ '+'*+ 304,419 +}| '| 0.134%

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B2. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 40 μg/L 28,289 0 0 0 0.000% 0.000% 0.000%	
 28,289 0 0 0 0.000% 0.000% 0.000%

	
 28,289 0 0 0 0.000% 0.000% 0.000%

> 0.9 μg/L 28,289 30 1 0 0.106% 0.004% 0.000%

> 40 μg/L 2,808 0 0 0 0.000% 0.000% 0.000%	
 2,808 0 0 0 0.000% 0.000% 0.000%

	
 2,808 1 1 1 0.036% 0.036% 0.036%

> 0.9 μg/L 2,808 25 1 1 0.890% 0.036% 0.036%

> 40 μg/L *= 0 0 0 0.000% 0.000% 0.000%	
 *= 0 0 0 0.000% 0.000% 0.000%

	
 *= 1 1 1 0.003% 0.003% 0.003%

> 0.9 μg/L *= 55 2 1 | 0.006% 0.003%

% Systems Exceeding Threshold

Source 

Water 

Type

Ground 

Water

Surface 

Water

Combined 

Ground & 

Surface 

Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B2. Carbofuran – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 40 μg/L	


	


> 0.9 μg/L

> 40 μg/L	


	


> 0.9 μg/L

> 40 μg/L	


	


> 0.9 μg/L

Source 

Water 

Type

Ground 

Water

Surface 

Water

Combined 

Ground & 

Surface 

Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

}*=* 0 0 0 0.000% 0.000% 0.000%

}*=* 0 0 0 0.000% 0.000% 0.000%

}*=* 0 0 0 0.000% 0.000% 0.000%

}*=* 1,138,494 220 0 1.842% 0.0004% 0.000%

}*+* 0 0 0 0.000% 0.000% 0.000%

}*+* 0 0 0 0.000% 0.000% 0.000%

}*+* 3,186 3,186 3,186 0.003% 0.003% 0.003%

}*+* **} 3,186 3,186 | 0.003% 0.003%}*=*' 0 0 0 0.000% 0.000% 0.000%

}*=*' 0 0 0 0.000% 0.000% 0.000%

}*=*' 3,186 3,186 3,186 0.002% 0.002% 0.002%

}*=*' 8,840,125 3,406 3,186 5.263% 0.002% 0.002%

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B3. Carbon tetrachloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 46,190 5 5 5 0.011% 0.011% 0.011%

	
 46,190 13   +| }| }|

	
 46,190 54 46 36 0.117% 0.100% +|

> 0.5 μg/L 46,190 = 101 76 0.634% =| 0.165%

> 5 μg/L '*} 0 0 0 0.000% 0.000% 0.000%

	
 '*} 0 0 0 0.000% 0.000% 0.000%

	
 '*} 5 4 4 0.117% 0.094% 0.094%

> 0.5 μg/L '*} 133 17 + | 0.399% ++|

> 5 μg/L 50,446 5 5 5 0.010% 0.010% 0.010%

	
 50,446 13   }| '| '|

	
 50,446 59 50 40 0.117% 0.099% 0.079%

> 0.5 μg/L 50,446 '} + +' +''| '| 0.167%

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B3. Carbon tetrachloride 

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+}*=*' 1,746 1,746 1,746 | | |

+}*=*' *++ *+ *+ 0.007% 0.006% 0.006%

+}*=*' 60,156 +*+ *++ 0.070% 0.067% '|

+}*=*' *}+*=+ =*+ 131,766 +=| +'| 0.153%

'** 0 0 0 0.000% 0.000% 0.000%

'** 0 0 0 0.000% 0.000% 0.000%

'** '*+ *=+ *=+ 0.146% 0.110% 0.110%

'** 9,450,131 =* }*} }'| '| }+|}*='*+ 1,746 1,746 1,746 0.001% 0.001% 0.001%

}*='*+ *++ *+ *+ 0.003% | |

}*='*+ }'*+}' *=} +=*+' 0.117% 0.093% +'|

}*='*+ *+=*= 749,743 }*= '++}| 0.330% }|

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B4. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 2 μg/L 28,808 1 1 1 0.003% 0.003% 0.003%	
 28,808 2 2 1 0.007% 0.007% 0.003%> 2 μg/L 3,033 0 0 0 0.000% 0.000% 0.000%	
 3,033 0 0 0 0.000% 0.000% 0.000%

> 2 μg/L 31,841 1 1 1 0.003% 0.003% 0.003%	
 31,841 2 2 1 0.006% 0.006% 0.003%

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B4. Chlordane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 2 μg/L	
> 2 μg/L	
> 2 μg/L	


Threshold Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

66,936,780 80 80 80 0.0001% 0.0001% 0.0001%

66,936,780 116 116 80 0.0002% 0.0002% 0.0001%

115,100,195 0 0 0 0.000% 0.000% 0.000%

115,100,195 0 0 0 0.000% 0.000% 0.000%

182,036,975 80 80 80 0.00004% 0.00004% 0.00004%

182,036,975 116 116 80 0.0001% 0.0001% 0.0000%

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B5. 1,2-Dibromo-3-chloropropane (DBCP) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 0.2 μg/L 34,602 38 38 38 0.110% 0.110% 0.110%	
 34,602 85 82 81 0.246% 0.237% 0.234%> 0.2 μg/L 3,016 4 4 4 0.133% 0.133% 0.133%	
 3,016 12 11 11 0.398% 0.365% 0.365%> 0.2 μg/L 37,618 42 42 42 0.112% 0.112% 0.112%	
 37,618 97 93 92 0.258% 0.247% 0.245%

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined Ground 

& Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B5. 1,2-Dibromo-3-chloropropane 

> 0.2 μg/L	
> 0.2 μg/L	
> 0.2 μg/L	


Source Water 

Type

Ground Water

Surface Water

Combined Ground 

& Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

73,552,992 15,947 15,947 15,947 0.022% 0.022% 0.022%

73,552,992 391,923 385,285 195,179 0.533% 0.524% 0.265%

120,196,347 9,246 9,246 9,246 0.008% 0.008% 0.008%

120,196,347 990,387 986,013 986,013 0.824% 0.820% 0.820%

193,749,339 25,193 25,193 25,193 0.013% 0.013% 0.013%

193,749,339 1,382,310 1,371,298 1,181,192 0.713% 0.708% 0.610%

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B6. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 46,185 3 3 3 0.006% 0.006% 0.006%

	
 46,185 9 9 8 0.019% 0.019% 0.017%

	
 46,185 43 35 = 0.093% 0.076% 0.063%

> 0.5 μg/L 46,185 190 77 60 0.411% 0.167% 0.130%

> 5 μg/L '* 0 0 0 0.000% 0.000% 0.000%

	
 '* 0 0 0 0.000% 0.000% 0.000%

	
 '* 3  1 0.070% 0.047% |

> 0.5 μg/L '* 38 5 3 0.893% 0.117% 0.070%

> 5 μg/L *'' 3 3 3 0.006% 0.006% 0.006%

	
 *'' 9 9 8 0.018% 0.018% 0.016%

	
 *'' 46 37 30 0.091% 0.073% 0.059%

> 0.5 μg/L *'' + + 63 '| 0.163% |

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B6. 1,2-Dichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+}*=*= 151 151 151 | | |

+}*=*= 873 873 833 0.001% 0.001% 0.001%

+}*=*= ==*' =*=' +*=} 0.115% 0.105% 0.095%

+}*=*= 963,134 135,637 =* 1.115% 0.157% 0.138%

140,541,198 0 0 0 0.000% 0.000% 0.000%

140,541,198 0 0 0 0.000% 0.000% 0.000%

140,541,198 90,390 '*} 4,750 0.064% 0.039% 0.003%

140,541,198 7,359,474 141,310 90,390 | 0.101% 0.064%}*=*== 151 151 151 0.0001% 0.0001% 0.0001%

}*=*== 873 873 833 0.0004% 0.0004% 0.0004%

}*=*== 189,664 '* 87,146 0.084% 0.064% 0.038%

}*=*== +**}+ }*=' =*} 3.667% | =|

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B7. Dichloromethane (Methylene dichloride) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 45,918 16 15 12 0.035% 0.033% 0.026%

	
 45,918 48 46 42 0.105% 0.100% 0.091%

	
 45,918 240 181 151 0.523% 0.394% 0.329%

> 0.5 μg/L 45,918 1,251 494 329 2.724% 1.076% 0.716%

> 5 μg/L 4,251 1 1 1 0.024% 0.024% 0.024%

	
 4,251 5 5 4 0.118% 0.118% 0.094%

	
 4,251 36 27 18 0.847% 0.635% 0.423%

> 0.5 μg/L 4,251 306 85 54 7.198% 2.000% 1.270%

> 5 μg/L 50,169 17 16 13 0.034% 0.032% 0.026%

	
 50,169 53 51 46 0.106% 0.102% 0.092%

	
 50,169 276 208 169 0.550% 0.415% 0.337%

> 0.5 μg/L 50,169 1,557 579 383 3.104% 1.154% 0.763%

% Systems Exceeding Threshold

Source 

Water 

Type

Ground 

Water

Surface 

Water

Combined 

Ground & 

Surface 

Water

Threshold Total # Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B7. Dichloromethane 

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

Source 

Water 

Type

Ground 

Water

Surface 

Water

Combined 

Ground & 

Surface 

Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

86,307,048 10,219 10,119 9,148 0.012% 0.012% 0.011%

86,307,048 36,518 33,009 31,607 0.042% 0.038% 0.037%

86,307,048 1,273,387 1,152,919 791,105 1.475% 1.336% 0.917%86,307,048 6,645,442 1,910,810 1,385,316 7.700% 2.214% 1.605%

140,537,012 1,800 1,800 1,800 0.001% 0.001% 0.001%

140,537,012 7,435 7,435 7,350 0.005% 0.005% 0.005%

140,537,012 243,772 232,890 154,950 0.173% 0.166% 0.110%

140,537,012 25,125,784 1,586,371 458,789 17.878% 1.129% 0.326%226,844,060 12,019 11,919 10,948 0.005% 0.005% 0.005%

226,844,060 43,953 40,444 38,957 0.019% 0.018% 0.017%

226,844,060 1,517,159 1,385,809 946,055 0.669% 0.611% 0.417%226,844,060 31,771,226 3,497,181 1,844,105 14.006% 1.542% 0.813%

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B8. 2,4-Dichlorophenoxyacetic Acid (2,4-D) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 70 μg/L 30,172 0 0 0 0.000% 0.000% 0.000%'	
 30,172 0 0 0 0.000% 0.000% 0.000%	
 30,172 0 0 0 0.000% 0.000% 0.000%> 70 μg/L * 0 0 0 0.000% 0.000% 0.000%'	
 * 0 0 0 0.000% 0.000% 0.000%

	
 * 0 0 0 0.000% 0.000% 0.000%> 70 μg/L 33,187 0 0 0 0.000% 0.000% 0.000%'	
 33,187 0 0 0 0.000% 0.000% 0.000%	
 33,187 0 0 0 0.000% 0.000% 0.000%

% Systems Exceeding Threshold

Source Water Type

Ground Water

Surface Water

Combined Ground 

& Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review Revised September 2010

Table B8. 2,4-Dichlorophenoxyacetic Acid 

> 70 μg/L'	
	
> 70 μg/L'	
	
> 70 μg/L'	
	


Source Water Type

Ground Water

Surface Water

Combined Ground 

& Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

67,200,878 0 0 0 0.000% 0.000% 0.000%

67,200,878 0 0 0 0.000% 0.000% 0.000%

67,200,878 0 0 0 0.000% 0.000% 0.000%

** 0 0 0 0.000% 0.000% 0.000%

** 0 0 0 0.000% 0.000% 0.000%

** 0 0 0 0.000% 0.000% 0.000%

+*'*+ 0 0 0 0.000% 0.000% 0.000%

+*'*+ 0 0 0 0.0000% 0.0000% 0.0000%

+*'*+ 0 0 0 0.000% 0.000% 0.000%

# Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B9. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 46,180 0 0 0 0.000% 0.000% 0.000%

	
 46,180    0.004% 0.004% 0.004%

	
 46,180 }   0.056% 0.050% '|

> 0.5 μg/L 46,180 + 59 46 ==| +| 0.100%

> 5 μg/L '* 0 0 0 0.000% 0.000% 0.000%

	
 '* 0 0 0 0.000% 0.000% 0.000%

	
 '* 1 1 1 | | |

> 0.5 μg/L '* 14  1 =| '| |

> 5 μg/L *' 0 0 0 0.000% 0.000% 0.000%

	
 *'    0.004% 0.004% 0.004%

	
 *'  '  0.054% 0.048% '|

Threshold

> 0.5 μg/L *'  61 ' | | =|

Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B9. 1,2-Dichloropropane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


Threshold

> 0.5 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+}*=*= 0 0 0 0.000% 0.000% 0.000%

+}*=*=    0.0001% 0.0001% 0.0001%

+}*=*= *'' * 18,656 '| | |

+}*=*= }'*} +}*}' * '=| 0.100% |

'*}*' 0 0 0 0.000% 0.000% 0.000%

'*}*' 0 0 0 0.000% 0.000% 0.000%

'*}*' }*}=} }*}=} }*}=} 0.189% 0.189% 0.189%

'*}*' **} '*}=} }*}=} | =| 0.189%}*=*' 0 0 0 0.000% 0.000% 0.000%

}*=*'    0.0001% 0.0001% 0.0001%

}*=*' +}*' +* +'* }| }| |

}*=*' +*'* 494,460 =}* }| +| |

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B10. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 100 μg/L 12,632 0 0 0 0.000% 0.000% 0.000%

	
 12,632 0 0 0 0.000% 0.000% 0.000%

> 100 μg/L *' 0 0 0 0.000% 0.000% 0.000%

	
 *' 1 1 1 0.066% 0.066% 0.066%

> 100 μg/L '*} 0 0 0 0.000% 0.000% 0.000%

	
 '*} 1 1 1 0.007% 0.007% 0.007%

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B10. Endothall – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 100 μg/L

	


> 100 μg/L

	


> 100 μg/L

	


Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

''*'*+ 0 0 0 0.000% 0.000% 0.000%

''*'*+ 0 0 0 0.000% 0.000% 0.000%

'*'*' 0 0 0 0.000% 0.000% 0.000%

'*'*' 10,000 10,000 10,000 0.013% 0.013% 0.013%

+*}*+ 0 0 0 0.000% 0.000% 0.000%

+*}*+ 10,000 10,000 10,000 +| +| +|

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B11. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Threshold

> 0.4 μg/L 29,965 1 1 1 0.003% 0.003% 0.003%	
 29,965 1 1 1 0.003% 0.003% 0.003%	
 29,965 41 41 41 0.137% 0.137% 0.137%> 0.4 μg/L 3,055 0 0 0 0.000% 0.000% 0.000%	
 3,055 0 0 0 0.000% 0.000% 0.000%	
 3,055 1 1 1 0.033% 0.033% 0.033%

> 0.4 μg/L 33,020 1 1 1 0.003% 0.003% 0.003%	
 33,020 1 1 1 0.003% 0.003% 0.003%	
 33,020 42 42 42 0.127% 0.127% 0.127%

Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B11. Heptachlor – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Threshold

> 0.4 μg/L	
	
> 0.4 μg/L	
	
> 0.4 μg/L	
	


Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

67,922,151 325 325 325 0.0005% 0.0005% 0.0005%

67,922,151 325 325 325 0.0005% 0.0005% 0.0005%

67,922,151 23,112 23,112 23,112 0.034% 0.034% 0.034%

116,521,633 0 0 0 0.000% 0.000% 0.000%

116,521,633 0 0 0 0.000% 0.000% 0.000%

116,521,633 8,380 8,380 8,380 0.007% 0.007% 0.007%

184,443,784 325 325 325 0.0002% 0.0002% 0.0002%

184,443,784 325 325 325 0.0002% 0.0002% 0.0002%

184,443,784 31,492 31,492 31,492 0.017% 0.017% 0.017%

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B12. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 0.2 μg/L 29,961 1 1 1 0.003% 0.003% 0.003%	
 29,961 3 3 3 0.010% 0.010% 0.010%> 0.2 μg/L 3,054 0 0 0 0.000% 0.000% 0.000%

	
 3,054 0 0 0 0.000% 0.000% 0.000%> 0.2 μg/L 33,015 1 1 1 0.003% 0.003% 0.003%	
 33,015 3 3 3 0.009% 0.009% 0.009%

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B12. Heptachlor Epoxide – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 0.2 μg/L	
> 0.2 μg/L	
> 0.2 μg/L	


Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

67,983,066 325 325 325 0.0005% 0.0005% 0.0005%

67,983,066 14,419 14,419 14,419 0.021% 0.021% 0.021%

116,494,709 0 0 0 0.000% 0.000% 0.000%

116,494,709 0 0 0 0.000% 0.000% 0.000%

184,477,775 325 325 325 0.0002% 0.0002% 0.0002%

184,477,775 14,419 14,419 14,419 0.008% 0.008% 0.008%

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B13. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 1 μg/L 29,793 3 3 3 0.010% 0.010% 0.010%

	
 29,793 3 3 3 0.010% 0.010% 0.010%> 0.1 μg/L 29,793 20 8 8 0.067% 0.027% 0.027%

> 1 μg/L 3,033 0 0 0 0.000% 0.000% 0.000%

	
 3,033 1 1 1 0.033% 0.033% 0.033%> 0.1 μg/L 3,033 39 8 1 1.286% 0.264% 0.033%

> 1 μg/L 32,826 3 3 3 0.009% 0.009% 0.009%

	
 32,826 4 4 4 0.012% 0.012% 0.012%> 0.1 μg/L 32,826 = 16 9 0.180% 0.049% 0.027%

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B13. Hexachlorobenzene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 1 μg/L

	
> 0.1 μg/L

> 1 μg/L

	
> 0.1 μg/L

> 1 μg/L

	
> 0.1 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

}*=*= 2,273 2,273 2,273 0.003% 0.003% 0.003%

}*=*= 2,273 2,273 2,273 0.003% 0.003% 0.003%

}*=*= 639,313 6,741 6,741 0.941% 0.010% 0.010%

116,167,630 0 0 0 0.000% 0.000% 0.000%

116,167,630 2,671 2,671 2,671 0.002% 0.002% 0.002%

116,167,630 *'+*== 87,448 2,671 2.139% | 0.002%184,124,823 2,273 2,273 2,273 0.001% 0.001% 0.001%

184,124,823 4,944 4,944 4,944 0.003% 0.003% 0.003%

184,124,823 3,124,412 94,189 9,412 1.697% | |

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B14. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 50 μg/L 29,767 0 0 0 0.000% 0.000% 0.000%'	
 29,767 0 0 0 0.000% 0.000% 0.000%	
 29,767 0 0 0 0.000% 0.000% 0.000%> 50 μg/L *' 0 0 0 0.000% 0.000% 0.000%'	
 *' 0 0 0 0.000% 0.000% 0.000%	
 *' 0 0 0 0.000% 0.000% 0.000%> 50 μg/L 32,801 0 0 0 0.000% 0.000% 0.000%'	
 32,801 0 0 0 0.000% 0.000% 0.000%	
 32,801 0 0 0 0.000% 0.000% 0.000%

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B14. Hexachlorocyclopentadiene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 50 μg/L'	
	
> 50 μg/L'	
	
> 50 μg/L'	
	


Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

67,981,852 0 0 0 0.000% 0.000% 0.000%

67,981,852 0 0 0 0.000% 0.000% 0.000%

67,981,852 0 0 0 0.000% 0.000% 0.000%

116,756,578 0 0 0 0.000% 0.000% 0.000%

116,756,578 0 0 0 0.000% 0.000% 0.000%

116,756,578 0 0 0 0.000% 0.000% 0.000%

+'*+*' 0 0 0 0.000% 0.000% 0.000%

+'*+*' 0 0 0 0.000% 0.000% 0.000%

+'*+*' 0 0 0 0.000% 0.000% 0.000%

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B15. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 200 μg/L 28,100 0 0 0 0.000% 0.000% 0.000%	
 28,100 0 0 0 0.000% 0.000% 0.000%

> 2 μg/L 28,100 14 11 6 0.050% 0.039% 0.021%

> 200 μg/L 2,776 0 0 0 0.000% 0.000% 0.000%	
 2,776 0 0 0 0.000% 0.000% 0.000%

> 2 μg/L 2,776 3 2 2 0.108% 0.072% 0.072%

> 200 μg/L 30,876 0 0 0 0.000% 0.000% 0.000%	
 30,876 0 0 0 0.000% 0.000% 0.000%

> 2 μg/L 30,876 17 13 8 0.055% 0.042% 0.026%

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B15. Oxamyl (Vydate) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 200 μg/L	


> 2 μg/L

> 200 μg/L	


> 2 μg/L

> 200 μg/L	


> 2 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

61,701,854 0 0 0 0.000% 0.000% 0.000%

61,701,854 0 0 0 0.000% 0.000% 0.000%

61,701,854 38,142 37,979 3,669 0.062% 0.062% 0.006%

105,676,577 0 0 0 0.000% 0.000% 0.000%

105,676,577 0 0 0 0.000% 0.000% 0.000%

105,676,577 257,848 3,386 3,386 0.244% 0.003% 0.003%

167,378,431 0 0 0 0.000% 0.000% 0.000%

167,378,431 0 0 0 0.000% 0.000% 0.000%

167,378,431 295,990 41,365 7,055 0.177% 0.025% 0.004%

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B16. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 46,180 20 20 20 0.043% 0.043% 0.043%

	
 46,180 61 58 55 0.132% 0.126% 0.119%

	
 46,180 244 214 190 0.528% 0.463% 0.411%

> 0.5 μg/L 46,180 860 446 356 1.862% 0.966% 0.771%

> 5 μg/L 4,256 5 3 3 0.117% 0.070% 0.070%

	
 4,256 14 13 13 0.329% 0.305% 0.305%

	
 4,256 42 37 30 0.987% 0.869% 0.705%

> 0.5 μg/L 4,256 145 73 56 3.407% 1.715% 1.316%

> 5 μg/L 50,436 25 23 23 0.050% 0.046% 0.046%

	
 50,436 75 71 68 0.149% 0.141% 0.135%

	
 50,436 286 251 220 0.567% 0.498% 0.436%

> 0.5 μg/L 50,436 1,005 519 412 1.993% 1.029% 0.817%

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B16. Tetrachloroethylene (PCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

86,396,173 81,488 81,488 81,488 0.094% 0.094% 0.094%

86,396,173 461,738 455,716 411,244 0.534% 0.527% 0.476%

86,396,173 2,498,326 2,122,956 1,933,039 2.892% 2.457% 2.237%86,396,173 11,851,080 4,827,257 3,399,163 13.717% 5.587% 3.934%

140,612,382 992,445 546,718 546,718 0.706% 0.389% 0.389%

140,612,382 1,244,255 1,236,118 1,236,118 0.885% 0.879% 0.879%

140,612,382 8,207,545 8,053,939 7,691,532 5.837% 5.728% 5.470%140,612,382 16,303,826 9,744,394 9,009,278 11.595% 6.930% 6.407%

227,008,555 1,073,933 628,206 628,206 0.473% 0.277% 0.277%227,008,555 1,705,993 1,691,834 1,647,362 0.752% 0.745% 0.726%

227,008,555 10,705,871 10,176,895 9,624,571 4.716% 4.483% 4.240%227,008,555 28,154,906 14,571,651 12,408,441 12.403% 6.419% 5.466%

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B17. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 1,000 μg/L 46,193 1 1 1 0.002% 0.002% 0.002%

}	
 46,193 2 2 2 0.004% 0.004% 0.004%	
 46,193 2 2 2 0.004% 0.004% 0.004%

> 1,000 μg/L '*+ 0 0 0 0.000% 0.000% 0.000%

}	
 '*+ 0 0 0 0.000% 0.000% 0.000%	
 '*+ 0 0 0 0.000% 0.000% 0.000%

> 1,000 μg/L *' 1 1 1 0.002% 0.002% 0.002%

}	
 *' 2 2 2 0.004% 0.004% 0.004%	
 *' 2 2 2 0.004% 0.004% 0.004%

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B17. Toluene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 1,000 μg/L

}	
	


> 1,000 μg/L

}	
	


> 1,000 μg/L

}	
	


Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+}*'*'}    0.001% 0.001% 0.001%

+}*'*'} +' +' +' 0.001% 0.001% 0.001%

+}*'*'} +' +' +' 0.001% 0.001% 0.001%

'** 0 0 0 0.000% 0.000% 0.000%

'** 0 0 0 0.000% 0.000% 0.000%

'** 0 0 0 0.000% 0.000% 0.000%

}*=*    0.0002% 0.0002% 0.0002%

}*=* +' +' +' 0.0004% 0.0004% 0.0004%

}*=* +' +' +' 0.0004% 0.0004% 0.0004%

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B18. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 3 μg/L 27,718 4 3 3 0.014% 0.011% 0.011%

	
 27,718    0.018% 0.018% 0.018%

> 1 μg/L 27,718 7   | 0.018% 0.018%> 3 μg/L 2,669 0 0 0 0.000% 0.000% 0.000%

	
 2,669 0 0 0 0.000% 0.000% 0.000%

> 1 μg/L 2,669 2 0 0 | 0.000% 0.000%> 3 μg/L 30,387 4 3 3 0.013% 0.010% 0.010%

	
 30,387    0.016% 0.016% 0.016%

> 1 μg/L 30,387 9   0.030% 0.016% 0.016%

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B18. Toxaphene – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 3 μg/L

	


> 1 μg/L> 3 μg/L

	


> 1 μg/L> 3 μg/L

	


> 1 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

60,886,049 22,989 22,691 22,691 0.038% 0.037% 0.037%

60,886,049 23,429 23,429 23,429 0.038% 0.038% 0.038%

60,886,049 27,713 23,429 23,429 0.046% 0.038% 0.038%

==*}*+ 0 0 0 0.000% 0.000% 0.000%

==*}*+ 0 0 0 0.000% 0.000% 0.000%

==*}*+ * 0 0 0.260% 0.000% 0.000%

160,012,134 22,989 22,691 22,691 0.014% 0.014% 0.014%

160,012,134 23,429 23,429 23,429 | | |

160,012,134 +*' 23,429 23,429 0.178% | |

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B19. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 45,942 0 0 0 0.000% 0.000% 0.000%	
 45,942 1 1 1 0.002% 0.002% 0.002%

	
 45,942 1 1 1 0.002% 0.002% 0.002%

> 5 μg/L '* 0 0 0 0.000% 0.000% 0.000%

	
 '* 0 0 0 0.000% 0.000% 0.000%

	
 '* 0 0 0 0.000% 0.000% 0.000%

> 5 μg/L 50,195 0 0 0 0.000% 0.000% 0.000%	
 50,195 1 1 1 0.002% 0.002% 0.002%

	
 50,195 1 1 1 0.002% 0.002% 0.002%

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B19. 1,1,2-Trichloroethane – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 5 μg/L	


	


> 5 μg/L	


	


> 5 μg/L	


	


Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+}*'*+= 0 0 0 0.000% 0.000% 0.000%

+}*'*+= 700 700 700 0.001% 0.001% 0.001%

+}*'*+= 700 700 700 0.001% 0.001% 0.001%

'*}*= 0 0 0 0.000% 0.000% 0.000%

'*}*= 0 0 0 0.000% 0.000% 0.000%

'*}*= 0 0 0 0.000% 0.000% 0.000%

226,851,469 0 0 0 0.000% 0.000% 0.000%

226,851,469 700 700 700 | | |

226,851,469 700 700 700 | | |

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B20. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 5 μg/L 46,177 18 18 18 0.039% 0.039% 0.039%

	
 46,177 60 58 54 0.130% }| 0.117%

	
 46,177 = 181 160 0.453% =| 0.346%

> 0.5 μg/L 46,177 }' 334 } 1.351% | 0.578%

> 5 μg/L '* 7 7 7 0.165% 0.165% 0.165%

	
 '* 10 10 10 | | |

	
 '* 31   =| 0.635% 0.517%

> 0.5 μg/L '* 115 54 43 | }=| 1.011%

> 5 μg/L *'    0.050% 0.050% 0.050%

	
 *' 70 68 64 0.139% 0.135% |

	
 *' ' + + 0.476% '| 0.361%

> 0.5 μg/L *' 739 388 310 1.465% 0.769% 0.615%

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold % Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B20. Trichloroethylene (TCE) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

> 5 μg/L

	


	


> 0.5 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+}*=*= 50,410 50,410 50,410 0.058% 0.058% 0.058%

+}*=*= 307,930 '*= 140,973 0.356% | 0.163%

+}*=*= 1,911,987 1,686,897 *'* | 1.953% 1.559%+}*=*= +**} *==*+=} *'*+ =}| 3.391% =|

140,514,477 359,713 359,713 359,713 }| }| }|

140,514,477 4,456,573 4,456,573 4,456,573 | | |

140,514,477 8,458,791 6,594,945 6,051,956 }| 4.693% 4.307%140,514,477 }** =*=}* =*'* 11.566% 7.071% 6.741%

}*=*}+} '* '* '* 0.181% 0.181% 0.181%

}*=*}+} 4,764,503 '*}=*+ 4,597,546 | }| }|

}*=*}+} 10,370,778 +*+*+' 7,399,167 4.570% 3.650% }|}*=*}+} '**} *+}}* 11,883,875 10.688% 5.670% |

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold

Total Pop Served 

by Systems
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B21. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 2 μg/L 46,158 10 9 7 0.022% 0.019% 0.015%	
 46,158 20 17 14 0.043% 0.037% 0.030%

> 0.5 μg/L 46,158 104 41 28 0.225% 0.089% 0.061%

> 2 μg/L 4,253 1 1 1 0.024% 0.024% 0.024%	
 4,253 1 1 1 0.024% 0.024% 0.024%

> 0.5 μg/L 4,253 32 8 4 0.752% 0.188% 0.094%

> 2 μg/L 50,411 11 10 8 0.022% 0.020% 0.016%	
 50,411 21 18 15 0.042% 0.036% 0.030%

> 0.5 μg/L 50,411 136 49 32 0.270% 0.097% 0.063%

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B21. Vinyl Chloride – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 2 μg/L	


> 0.5 μg/L

> 2 μg/L	


> 0.5 μg/L

> 2 μg/L	


> 0.5 μg/L

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

86,057,502 12,478 10,793 4,688 0.014% 0.013% 0.005%

86,057,502 54,796 21,736 16,526 0.064% 0.025% 0.019%

86,057,502 712,162 338,964 71,559 0.828% 0.394% 0.083%

140,406,921 1,365 1,365 1,365 0.001% 0.001% 0.001%

140,406,921 1,365 1,365 1,365 0.001% 0.001% 0.001%

140,406,921 1,363,671 426,745 411,827 0.971% 0.304% 0.293%226,464,423 13,843 12,158 6,053 0.006% 0.005% 0.003%

226,464,423 56,161 23,101 17,891 0.025% 0.010% 0.008%

226,464,423 2,075,833 765,709 483,386 0.917% 0.338% 0.213%

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B22. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

> 10,000 μg/L 43,726 0 0 0 0.000% 0.000% 0.000%

*	
 43,726 0 0 0 0.000% 0.000% 0.000%*	
 43,726 0 0 0 0.000% 0.000% 0.000%

> 10,000 μg/L 3,972 0 0 0 0.000% 0.000% 0.000%

*	
 3,972 0 0 0 0.000% 0.000% 0.000%*	
 3,972 0 0 0 0.000% 0.000% 0.000%

> 10,000 μg/L 47,698 0 0 0 0.000% 0.000% 0.000%

*	
 47,698 0 0 0 0.000% 0.000% 0.000%*	
 47,698 0 0 0 0.000% 0.000% 0.000%

% Systems Exceeding Threshold

Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Total # 

Systems

# Systems Exceeding Threshold
Appendix B - Analysis of Occ. Data from the 2nd Six-Year Review

Table B22. Xylenes (Total) – Summary of the Stage 1 (Peak) Analyses (Single detections > threshold of interest are not necessarily MCL violations)

Revised September 2010

> 10,000 μg/L

*	
*	


> 10,000 μg/L

*	
*	


> 10,000 μg/L

*	
*	


Source Water 

Type

Ground Water

Surface Water

Combined 

Ground & 

Surface Water

Threshold Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

Arithmetic 

System Mean 

using MRL

Arithmetic 

System Mean 

using 1/2 MRL

Arithmetic 

System Mean 

using 0

+*'+* 0 0 0 0.000% 0.000% 0.000%

+*'+* 0 0 0 0.000% 0.000% 0.000%

+*'+* 0 0 0 0.000% 0.000% 0.000%

134,323,023 0 0 0 0.000% 0.000% 0.000%

134,323,023 0 0 0 0.000% 0.000% 0.000%

134,323,023 0 0 0 0.000% 0.000% 0.000%

+** 0 0 0 0.000% 0.000% 0.000%

+** 0 0 0 0.000% 0.000% 0.000%

+** 0 0 0 0.000% 0.000% 0.000%

Total Pop Served 

by Systems

% Pop. Served by Systems Exceeding Threshold # Pop. Served by Systems Exceeding Threshold