# Occurrence Data from the Second Unregulated Contaminant Monitoring Regulation (UCMR 2)

# O ffice of Water (4607M) EPA -815-R-15-013 December 2015

## EPA

- OGWDW Occurrence Data from the UCMR 2



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# Executive Summary

T his report presents the United States Environmental Protection Agency ’s ( EPA ) analysis of the national occurrence of unregulated contaminants that were monitored in public water systems (PWSs) under the second Unregulated Contaminant Monitoring Regulation ( UCMR 2). The UCMR 2 monitoring was conducted for selected unregulated contaminants in drinking water under the authority of Section 1445(a)(2) of the Safe Drinking Water Act (SDWA), as amended in 1996. This r eport also presents an overview of the regulatory background for unregulated contaminant monitoring, the design and implementation of the UCMR 2 monitoring program , data management and quality assurance/quality control (QA/QC) , and the occurrence measures used and any limitations of those measures.

The UCMR program specifies a three -tiered approach for contaminant monitoring based on the availability of analytical methods and contaminant prioritization. Assessment Monitoring (List 1) is the largest in scop e of the three monitoring components (or tiers). Assessment Monitoring typically relies on analytical methods, techniques or technologies that are in common use by drinking water laboratories



# . Screening Survey ( List 2) monitoring typically relies on newer analytical methods that are not as commonly used, such that laboratory capacity to perform List 2 analyses may be limited



# . Pre

- Screen Testing (List 3) is often associated with analytical methods that are very recently developed and/or are particularly complex. 

# The Pre -Screen Testing provisions of the UCMR program were not required under UCMR 2.

The UCMR 2 program specified that all large (serving 10,001 – 100,000 people) and very large (serving more than 100,000 people) community water systems (CWSs) and n on- transient

non- community water systems (NTNCWSs), plus a statistically representative national sample of 800 small (serving 10,000 or fewer people) CWSs and NTNCWSs were required to monitor for the 10 Assessment Monitoring contaminants. Additionally, UCM R 2 required monitoring of the 15 Screening Survey contaminants by all very large systems , 320 selected large systems , and 480 selected small systems

.
The UCMR 2 sampling was co nducted from January 2008 to December 2010. The data

were collected from PWSs in all 50 states and 6 additional primacy entities. A ll of the applicable PWSs participated in the UCMR 2 monitoring, and collectively the systems submitted monitoring data of high quality. The UCMR 2 Data Quality Objectives (DQOs) required a small systems participation rate of at least 82.375%
, and required that at least 90% of all submitted data meet the established data acceptance criteria ; both requirements were met and surpassed.
EPA developed a two

- stage analytical approach to evaluate the UCMR 2 contaminant occurrence data. In Stage 1 , the data are fir st reviewed, quality- checked
, and characterized, and then analyzed to generate simple, clear non- parametric estimates of contaminant occurrence. For example, simple counts are made of the number of systems, and populations served by those systems, with at least one observed detection that has a concentration greater than the HRL, greater than 1⁄2 the HRL , or greater than or equal to the Minimum Repor ting Level ( MRL ) . Based on the Stage 1 analysis, any contaminant found to have significant occurrence can be anal yzed with a more rigorous Stage 2 analysis. In Stage 2 , statistical modeling is used to generate national probability estimates of contaminant occurrence based on estimated annual (or longer-

## EPA

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# term) mean concentrations of contaminants along with statistical measures of uncertainty and

error. This report presents the Stage 1 analysis only.

Occurrence measures are presented for different categories of systems so that occurrence can be assessed based on system characteristics such as source water type or system size. Given that ground water systems and surface water systems have different sampling sch edules
, it is important to evaluate occurrence sepa rately for the two source water types. EPA has also evaluate d contaminant occurrence separately for the different UCMR 2 system size categories. A census of large and very large systems, plus a sample of small systems, monitored for 10 Assessment Monitoring contaminants. A census of very large systems, plus a statistical sample of large and small systems monitored for 15 Screening Survey contaminants. UCMR 2 occurrence data from the large and very large systems that monitored for the Assessment Monitoring contaminants; and from very large systems that monitored for the Screening Survey contaminants support contaminant occurrence analyses that are representative (stat istically valid) at the s tate level. T he statistical sample s of small systems were insufficient to support a statistically rigorous s tate

- level occurrence analysis ; however , summary tables of all UCMR 2 monitoring results are presented for each s tate, t err itory , and tr ibe to provide a complete record of monitoring results by s tate are included in the Appendix.

In the final UCMR 2 data set, an average of 32,1 48 samples from 4,140 PWSs were collected for each of 10 Assessment Monitoring contaminants. Only 2 of the 10 Assessment Monitoring contaminants were detected – RDX and terbufos sulfone. Four detections of RDX (ranging from 1 μg/L to 1.1 μg/L ) were reported; none of these detections were greater than the HRL of 21 μg/L. One detection of terbufos su lfone was reported ; this detection (equal to 0.42 μg/L ) wa s greater than the HRL of 0.35 μg/L

. The remaining eight Assessment Monitoring contaminants (BDE- 47, BDE

- 99, BDE -100, BDE-153, dimethoate, 1,3-dinitrobenzene, HBB, and TNT) were not detected

.
In th e final UCMR 2 data set, an average of 11,1 69 samples from 1,198 PWSs were collected for each of the nine acetanilide parent and degradate h erbicides monitored under the Screening Survey. An average of 18,101 samples from 1,198 PWSs were collected for each of the six nitrosamines monitored under the Screening Survey. Ten of the 15 Screening Survey contaminants were detected – acetochlor ESA, alachlor ESA, metolachlor, metolachlor ESA, metolachlor OA, NDBA, NDEA, NDMA, NMEA, and NPYR

. UCMR 2 monitoring found no analytical detections for five Screening Survey contaminants (acetochlor, acetochlor OA, alachlor, alachlor OA, and NDPA) . Of the 10 Screening Survey contaminants detected , 7 contaminants had at least one detection greate r than their respective HRLs – a cetochlor ESA, alachlor ESA, NDBA, NDEA, NDMA, NMEA, and NPYR

. By far, the contaminant with the most detections was NDMA . NDMA was detected in 1,861 samples reported from 324 PWSs. NDMA detections ranged from 0.002 μg/L to 0.63 μg/L

. All detections were g reater than NDMA’s HRL of 0.0006 μg/L

.

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# Contents

E xecutive Summary

....................................................................................................................... iii
Contents ................................ .......................................................................................................... v Exhibits ................................ ......................................................................................................... vii Acronyms

................................ ....................................................................................................... ix
1 Introduction .................................................................................................................. 1
1.1 Regulatory Background ............................................................................................... 1 1.2 Two

- Stage Analytical Approach .................................................................................. 2 1.3 Analytical Tools ........................................................................................................... 3
2 UCMR 2 Program Overview ....................................................................................... 4
2.1 UCMR 2 Monitoring Design and Contaminant List .................................................... 4 2.2 Assessment Monitoring ................................................................................................ 7 2.3 Screening Survey ......................................................................................................... 8
3 UCMR 2 Data Description ......................................................................................... 10
3.1 Data Submittal Process .............................................................................................. 10 3.2 Data Management and Quality Assurance ................................................................. 11 3.3 Assessments of Data Representativeness and Completeness ..................................... 13 3.3.1 Data Representativeness ............................................................................................. 13 3.3.2 Completeness ............................................................................................................. 14 3.4 Additional Data Management Considerations ........................................................... 15 3.4.1 Population Adjustments ............................................................................................. 15 3.4.2 Temporal Information ................................................................................................ 15
4 Description of Stage 1 Analytical Method ................................................................. 17
4.1 Stage 1 Analysis ......................................................................................................... 17 4.2 Threshold Evaluations ................................................................................................ 18 4.3 Additional Considerations for Stage 1 Analysis ........................................................ 19 4.3.1 Ground Water and Surface Water Comparisons ........................................................ 19 4.3.2 Large System and Small System Totals ..................................................................... 20 4.3.3 Extrapolation of the Results ....................................................................................... 20 4.3.4 Stage 1 Analyses and the Statistically

- Weighted Sample of Small Systems ............. 21
5 Stage 1 Occurrence Estimates .................................................................................... 23
5.1 Assessment Monitoring Contaminants ...................................................................... 26 5.1.1 RDX ........................................................................................................................... 26 5.1.2 Terbufos Sulfone ........................................................................................................ 27 5.2 Screening Survey Contaminants with Detections ...................................................... 30 5.2.1 Acetochlor ESA ......................................................................................................... 31 5.2.2 Alachlor ESA ............................................................................................................. 35 5.2.3 Metolachlor ................................................................................................................ 38 5.2.4 Metolachlor ESA ........................................................................................................ 40 5.2.5 Metolachlor OA ......................................................................................................... 42

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# 5.2.6 NDBA ........................................................................................................................ 43 5.2.7 NDEA ......................................................................................................................... 46 5.2.8 NDMA ........................................................................................................................ 50 5.2.9 NMEA ........................................................................................................................ 54 5.2.10 NPYR ......................................................................................................................... 58
6 References .................................................................................................................. 62

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# Exhibits

E xhibit 2-1: Contaminants Monitored Under UCMR 2 ................................................................. 4
Exhibit 2-2: Number of PWSs that Monitored Under UCMR 2 .................................................... 9
Exhibit 3- 1 : UCMR 2 Required Data Elements ........................................................................... 11
Exhibit 4- 1 : Minimum Reporting Levels (MRLs) and Health Reference Levels (HRLs) for UCMR 2 Contaminants ............................................................................................... 18
Exhibit 4- 2 : Example Calculation of National Estimates (Extrapolations) for UCMR 2 Small and Large Systems (serving ≤ 100,000 people) for Screening Survey Contaminants ............ 21
Ex hi bit 5- 1: Summary of Stage 1 Occurrence Results for 10 Assessment Monitoring Contaminants and 15 Screening Survey Contaminants .................................................... 24
Exhibit 5- 2 : Summary of Stage 1 Occurrence Results for 10 Assessment Monitoring Contaminants and 15 Screening Survey Contaminants .................................................... 25
Exhibit 5- 3 : RDX National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - All Detections .................................. 26
Exhibit 5-4: Terbufos Sulfone National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - All Detecti ons ... 28
Exhibit 5-5: Terbufos Sulfone National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

................................................................................................ ................................... 29
Exhibit 5-6: Terbufos Sulfone National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - Detections > HRL

................................................................................................ ........................................... 30
Exhibit 5- 7 : Acetochlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections ....................... 31
Exhibit 5-8: Acetochlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL ............. 33
Exhibit 5- 9 : Acetochlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL ................. 34
Exhibit 5- 1 0: Alachlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections ....................... 35
Exhibit 5- 1 1: Alachlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL ............. 37
Exhibit 5- 1 2: Alachlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL ................. 38
Exhibit 5- 1 3: Metolachlor National Occurrence Measures from UCMR 2 Screening Survey Data

- Summary of System a nd Population Served Data - All Detections ............................... 39
Exhibit 5- 1 4: Metolachlor ESA National Occurrence Measures from UCMR 2 Screening Sur vey Data - Summary of System and Population Served Data - All Detections ....................... 41

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# Exhibit 5- 15: Metolachlor OA National Occurrence Measu res from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections ....................... 42
Exhibit 5- 1 6: NDBA Natio nal Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections .................................. 44
Exhibit 5- 1 7: NDBA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL ....................... 45
Exhibit 5- 1 8: NDBA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL ........................... 46
Exhibit 5- 1 9: NDEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections .................................. 47
Exhibit 5- 2 0: NDEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL ....................... 48
Exhibit 5- 2 1: NDEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL ........................... 49
Exhibit 5- 2 2: NDMA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Da ta - All Detections .................................. 51
Exhibit 5- 2 3: NDMA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL ....................... 52
Exhibit 5- 2 4: NDMA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL ........................... 53
Exhibit 5- 2 5: NMEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections .................................. 55
Exhibit 5- 2 6: NMEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data – Detections > 1⁄2 HRL ....................... 56
Exhibit 5-27: NM EA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL ........................... 57
Exhibit 5- 2 8: NPYR National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections .................................. 58
Exhibit 5- 2 9: NPYR National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL ....................... 60
Exhibit 5- 3 0: NPYR National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL ........................... 61

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# Acronyms

BDE

- 47 2,2',4,4'

- T etrabromodiphenyl ether
BDE

- 99 2,2',4,4',5

- P entabromodiphenyl ether
BDE

- 100 2,2',4,4',6

- P entabromodiphenyl ether
BDE

- 153 2,2',4,4',5,5'

- H exabromodiphenyl ether
CAS RN Chemical Abstract Services Registry Number
CCL Candidate Contaminant List
CDX Central Data Exchange
CWS Community Water System
CWSS Community Water System Survey DQO Data Quality Objective
DSMRT Distribution System Maximum Residence Time
EPTDS Entry Point to the Distribution System
EPA Environmental Protection Agency
ESA Ethane Sulfonic A cid
GW Ground Water
GUDI Ground Water Under Direct Influence (of Surface Water)
HBB 2,2',4,4',5,5'

- H exabromobiphenyl
HRL Health Reference Level
MCL Maximum Contaminant Level
MRL Minimum Reporting Level (or Limit)
NCOD National Contaminant Occurrence Database
NDBA N

- N itroso

- di

- n

- butylamine
NDEA N

- N itroso

- diethylamine
NDMA N

- N itroso

- dimethylamine
NDPA N

- N itroso

- di

- n

- propylamine
NMEA N

- N itroso

- methylethylamine
NPDWR National Primary Drinking Water Regulations
NPYR N

- N itroso

- pyrrolidine
NTNCWS Non

- Transient Non

- Community Water System
OA O xanilic A cid
OGWDW Office of Ground Water and Drinking Water

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# PWS Public Water System
PWSID Public Water System Identification Number QA Quality Assurance QC Quality Control
RD Regulatory Determination
RDX H exahydro

- 1,3,5

- trinitro 1,3,5

- triazine
SDWA Safe Drinking Water Act
SDWARS Safe Drinking Water Accession and Review System
SDWIS/Fed Safe Drinking Water Information System / Federal Version
SW Surface Water
TNCWS Transient Non

- Community Water System
TNT 2,4,6

- T rinitrotoluene
UCM Unregulated Contaminant Monitoring
UCMR Unregulated Contaminant Monitoring Regulation
USEPA United States Environmental Protection Agency

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# 1 Introduction

T he United States Environmental Protection Agency (EPA) conducted drinking water monitoring under the a gency’s second Unregulated Contaminant Monitoring Regulation ( UCMR 2 ). UCMR 2 monitoring was conducted for select ed unregulated contaminants in drinking water under the authority of Section 1445(a)(2) of the Safe Drinking Water Act (SDWA), as amended in 1996. Unregulated contaminan ts are contaminants for which there is no established or proposed National Primary Drinking Water Regulation (NPDWR). The intent of this monitoring is to gather more scientific information on these unregulated contaminants to support EPA assessments of national occurrence in drin king water to determine whether additional drinking water regulations are needed.
This report presents EPA’s analysis of the national occurrence of unregulated contaminants that were monitored at PWSs under the UCMR 2. The repor t additionally provides an overview of the regulatory background for unregulated contaminant monitoring, the design and implementation of the UCMR 2 monitoring program, data management and quality assurance/quality control (QA/QC), and the occurrence measu res used and any limitations of those measures.
The analyses presented in this report are based on the final UCMR 2 data set , which includes analytical results of water samples from all 4,620 systems that were expected to submit UCMR 2 data (100% complian ce). To accommodate final (late) UCMR 2 reporting, the data system remained open for submission of data through December 31, 2011. The final data set, including the sample data submitted through December 2011, is available on the UCMR website ( http://www.epa.gov/dwucmr/occurrence- data

- unregulated -contaminant-monitoring-rule#2 ). This document also provides detailed descriptions of EPA’s management and analysis of the data.



# 1.1 Regulatory Background

S DWA, as amended in 1986, required PWSs to monitor for specified unregulated contaminants on a five-year cycle and to report the monitoring results to the states. Monitoring of unregulated drinking water contaminants was historically conducted under the Un regulated Contaminant Monitoring (UCM) program. Data from the first round of monitoring (UCM Round 1) were collected from 1988 to 1992. All community water systems (CWSs) and non- transient non-community water systems (NTNCWSs) that had more than 150 servic e connections were required to conduct monitoring for select unregulated contaminants in drinking water. Smaller systems (t hose with 150 service connections or fewer ) were not universally required to participate in the monitoring, but they were required to be available for monitoring if the state decided such monitoring was necessary. In 1993, Congress amended SDWA to add new contaminants for unregulated contaminant monitoring. Data from UCM Round 2 monitoring were collected from 1993 to 1997.
The 1996 SDWA Amendments directed EPA to develop a revised program for the monitoring of unregulated contaminants and to , once every 5 years, identify no more than 30 contaminants to be monitored. The first UCMR (UCMR 1), and related rules, replaced the older UCM req uirements. The details of UCMR 1 were formally published in the Federal Register on

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# September 17, 1999 (64 FR 50556; USEPA, 1999). The UCMR program was designed to provide a national assessment of the occurrence of select unregulated contaminants in PWSs. UCMR 1 provided for the selection of the contaminants to be monitored, the requirements for PWSs that must conduct monitoring (from 2001-2005), and establishment of the process to report all UCMR monitoring results to EPA. The second UCMR ( UCMR 2 ; USEPA , 2007) established a somewhat revised monitoring program; this monitoring was primarily conducted between January 2008 and December 2010.

The 1996 amendments to SDWA instituted the Candidate Contaminant List (CCL) and the National Contaminant Occurrence Dat abase (NCOD) in addition to the UCMR programs. Development of each successive UCMR is coordinat ed with the CCL and the NCOD to provide the information EPA needs to determine which drinking water contaminants have the greatest potential to present a meaningful opportunity to reduce health risk through an NPWDR. UCMR provides EPA with the data necessary to identify contaminants that may require regulation as part of the CCL (USEPA, 2002) and to determine if a contaminant occurs at a frequency and level of pub lic health concern to inform the Regulatory Determination (RD) process (USEPA, 2008a). The UCMR , CCL and RD are coordinated parts of EPA’s risk management process, and they support and inform each other. The data collected through the UCMR program are stored in the NCOD to facilitate review of contaminant occurrence in drinking water. These data may guide the development of subsequent CCLs and ultimately support the EPA Administrator's regulatory determination s.

Data from UCMR 2 were used by EPA to evaluate the occurrence of contaminants on the third Contaminant Candidate List (CCL 3) for possible inclusion in the third round of Regulatory Determinations (RD 3) . Sixteen UCMR 2 contaminants we re included on CCL 3: 1,3- dinitrobenzene, a cetochlor, acetochlor ethane sulfonic acid (ESA), acetochlor oxanilic acid (OA),alachlor ESA, alachlor OA, dimethoate, metolachlor, metolachlor ESA, metolachlor OA, Nnitroso- diethylamine (NDEA), N -nitroso- dimethylamine (NDMA), N -nitroso-di-n-propylamine (NDPA), N -nitroso- pyrrolidine ( NPYR), hexahydro-1,3,5- trinitro -1,3,5-triazine (RDX), and terbufos sulfone. The nine UCMR 2 contaminants that are not on CCL 3 are: alachlor, 2,2',4,4',5,5'-hexabromodiphen yl ether (BDE -153), 2,2',4,4',5-pentabromodiphenyl et her (BDE

99), 2,2',4,4',6-pentabromodiphenyl ether (BDE-100), 2,2',4,4'- tetrabromodiphenyl ether (BDE

47), 2,2',4,4',5,5'-hexabromobiphenyl (HBB), N-nitroso-di-n-butylamine (NDBA), N-nitrosomet hylethylamine (NMEA), and 2,4,6- trinitrotoluene (TNT). For mor e information about the RD 3 program , see the Regulatory Determination 3 Support Document (USEPA, 2015) and the Protocol for the Regulatory Determination 3 ( USEPA , 2014a ).

To meet agency deadlines, EPA made use of UCMR data submitted through June 2011 in the deliberative process for RD 3. A draft version of this document, included in the docket for the preliminary regulatory determinations under RD 3 (79 FR 62715-62750; USEPA, 2014b), presented the data through June 2011 in the appendix. The June 2011 data are only slightly different from the final December 2011 UCMR 2 data set described in this report.



# 1.2 Two-Stage Analytical Approach

E PA developed a two

- stage analytical approach to evaluate the UCMR 2 contaminant occurrence data. This two

- stage analytical approach was previously developed (and peer reviewed) for other EPA Office of Ground Water and Drinking Water (OGWDW) national

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# occurrence studies, including the first Six- Year Review of National Prima ry Drinking Water Regulations (USEPA, 2003a), UCMR 1 (USEPA, 2008b), and previous rounds of the CCL and RD process (USEPA, 2002; USEPA, 2008a ).
The first stage of analysis provides a straightforward evaluation of occurrence of all contaminants under consideration. This “ Stage 1 analysis” of occurrence assesses the quality and characteristics of the data and then uses the data to conduct simple, conservative assessments for a broad evaluation of contaminant occurrence and population exposure. 1 

# Occurrence for each UCMR 2 contaminant was assessed based on samples, systems , and population served by systems. A typical Stage 1 analysis is the actual count (or percentage) of systems with at least one analytical detection 2 

# of a specific contaminant.
Based on the Stage 1 analysis, any contaminant found to have significant occurrence can be analyzed with a more rigorous “ Stage 2 analysis.” T he Stage 2 analysis is a parametric estimation based on calculation of mean contaminant concentrations at each system, and can provide occurrence estimates that help characterize contaminant occurrence at concentrations below the MRL. The Stage 2 occurrence analyses are less conservative than Stage 1 (since the Stage 2 analysis is based on estimated mean concentrations) and also provide occurrence estimates that may be more reflective of the potential for chronic exposure. This report presents only Stage 1 analyses.



# 1.3 Analytical Tools

D atabase manipulation, data quality checks, and overall data management were conducted in Microsoft Access. The data analyses were also conducted with Microsoft Access. Upon completion, results of the analyses were exported into Microsoft Excel for development of report tables that present the occurrence findings.

1 

# These analyses are conservative in that they are protective of human health (i.e., they are more likely to overestimate risks to human h ealth than underestimate them).

2 

# By definition, an analytical detection is a quantified concentration that is equal t o or greater than the laboratory method minimum reporting level, the MRL.

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# 2 UCMR 2 Program Overview

2.1 UCMR 2 Monitoring Design and Contaminant List

T he UCMR program design includes a three -tiered approach for monitoring of contaminants based on the availability of analytical methods (and related laboratory capacity) as well as risk

- based contaminant prioritization. Assessment Monitoring (List 1) is the largest in scope of the three monitoring components (or tiers) and typica lly relies on analytical methods, techniques or technologies that are in common use by drinking water laboratories 

# . Screening Survey (List 2) monitoring typically relies on newer analytical methods that are not as commonly used, such that laboratory capaci ty to perform List 2 analyses may be limited 

# . Pre

- Screen Testing (List 3) is often associated with analytical methods that are very recently developed and/or are particularly complex



# . Exhibit 2-1 presents the list of 10 Assessment Monitoring contaminants and 15 Screening Survey contaminants monitored under UCMR 2 . The Assessment Monitoring contaminants fall into three main groups: insecticides and insecticide degradate s, flame retardants, and explosives. The Screening Survey contaminants fall into two mai n groups: acetanilide herbicides with their degradation products, and nitrosamines. The Pre- Screen Testing provisions of the UCMR program were not implemented under UCMR 2.

Exhibit 2-1 : Contaminants Monitored Under UCMR 2

Contaminant Name Chemical Abstract Services Registry Number (CAS RN) Minimum Reporting

Level (MRL) Analytical Method Contaminant Use and Description



# . . A SSESSMENT 

# M ONITORING



# . .

. . Insecticide and Insecticide Degradate

. .

Dimethoate 60

- 51 -5 0.7 μg/L EPA 527 Insecticide used on cotton and other field crops, orchard crops, vegetable crops, in forestry, and residential uses

.

Terbufos sulfone 56070

- 16 -7 0.4 μg/L EPA 527 Parent compound ( terbufos ) used for systemic control of soil

- borne insects and nematodes in fields of corn, grain sorghum, and sugar beets

.

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# 5 Contaminant Name Chemical Abstract Services Registry Number (CAS RN) Minimum Reporting

Level (MRL) Analytical Method Contaminant Use and Description

. . Flame Retardants

. .

2,2',4,4'

- tetrabromodiphenyl ether (BDE

- 47) 5436

- 43

- 1 0.3 μg/L EPA 527 Flame retardant added to other materials (for products such as computer monitors, televisions, textiles, and plastic foams)

. 2,2',4,4',5

- pentabromodiphenyl ether (BDE

- 99) 60348

- 60

- 9 0.9 μg/L EPA 527 Flame retardant added to other materials (for products such as computer monitors, televisions, textiles, and p lastic foams)

. 2,2',4,4',5,5'

- hexabromodiphenyl ether (BDE

- 153) 68631

- 49

- 2 0.8 μg/L EPA 527 Flame retardant added to other materials (for products such as computer monitors, televisions, textiles, and plastic foams)

. 2,2',4,4',6

- pentabromodiphenyl ether (BDE

- 100) 189084

- 64

- 8 0.5 μg/L EPA 527 Flame retardant added to other materials (for products such as computer monitors, televisions, textiles, and plastic foams)

.
2,2',4,4',5,5'

- hexabromobiphenyl (HBB) 59080

- 40

- 9 0.7 μg/L EPA 527 Flame retardant additive; production of PBBEs ended in 1976 in US after an incident of significant accidental agricultural contamination in 1973

.

. . Explosives

. .

2,4,6

- trinitrotoluene (TNT) 118

- 96

- 7 0.8 μg/L EPA 529 Used as an explosive in bombs and grenades and as a propellant; small amounts used for industrial explosive applications, such as deep well and underwater blasting; chemical intermediate in manufacture of dyestuffs and photographic chemicals

.

1,3

- dinitrobenzene 99

- 65

- 0 0.8 μg/L EPA 529 Used in explos ives; also formed as a by

- product during the manufacture of the explosive trinitrotoluene (TNT); used in the manufacture of aramid fibers, spandex, and dyes

.

Hexahydro

- 1,3,5

- trinitro

1,3,5

- triazine (RDX) 121

- 82

- 4 1 μg/L EPA 529 Used in detonators, primers, mines, rocket boosters, and plastic explosives; also used in fireworks and demolition blocks, and as a rodenticide

.



# . . S CREENING 

# S URVEY



# . .

. . Acetanilide Parent Herbicides and Acetanilide Herbicide Degradates

. .

Acetochlor 34256

- 82

- 1 2 μg/L EPA 525.2 The active ingredient in a number of herbicides used on corn crops to control annual grasses and certain broadleaf weeds

.

Alachlor 15972

- 60

- 8 2 μg/L EPA 525.2 Widely used herbicide ; primarily used in the Midwest to control annual grasses and certain broadleaf weeds on crops such as corn, sorghum, and soybeans

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 6 Contaminant Name Chemical Abstract Services Registry Number (CAS RN) Minimum Reporting

Level (MRL) Analytical Method Contaminant Use and Description

Metolachlor 51218

- 45 -2 1 μg/L EPA 525.2 Broad spectrum herbicide used for general weed control in non

- crop areas; widely used on crops such as corn, cotton, peanuts, grass for seed production, nurseries, hedgerows/ fencerows, and landscape plantings

. Acetochlor ethane sulfonic acid (ESA) 187022

- 11

- 3 1 μg/L EPA 535 Degradation products of acetochlor

. Acetochlor oxanilic acid (OA) 184992

- 44

- 4 2 μg/L EPA 535 Degradation products of acetochlor

. Alachlor ethane sulfonic acid (ESA) 142363

- 53

- 9 1 μg/L EPA 535 Degradation products of alachlor

.
Alachlor oxanilic acid (OA) 171262

- 17

- 2 2 μg/L EPA 535 Degradation products of alachlor

. Metolachlor ethane sulfonic acid (ESA) 171118

- 09

- 5 1 μg/L EPA 535 Degradation products of metolachlor

.
Metolachlor oxanilic acid (OA) 152019

- 73

- 3 2 μg/L EPA 535 Degradation products of metolachlor

.

. . Nitrosamines

. . N

- nitroso

- diethylamine (NDEA) 55

- 18 -5 0.005 μg/L EPA 521 See description below table 1



## N

- nitroso

- dimethylamine (NDMA) 62

- 75 -9 0.002 μg/L EPA 521 See description below table 1



## N

- nitroso

- di

- n
- butylamine (NDBA) 924

- 16 -3 0.004 μg/L EPA 521 See description below table 1



## N

- nitroso

- di

- n
- propylamine (NDPA) 621

- 64 -7 0.007 μg/L EPA 521 See description below table 1



## N

- nitroso

- methylethylamine (NMEA) 10595

- 95 -6 0.003 μg/L EPA 521 See description below table 1



## N

- nitroso

- pyrrolidine (NPYR) 930

- 55 -2 0.002 μg/L EPA 521 See description below table 1

1 

## Nitrosamines can form as intermediates and byproducts in chemical synthesis and manufacture of rubber, leather, and plastics; can form spontaneously by reaction of precursor amines with nitrosating agents (nitrate and related compounds), or by action of nitrate

- reducing bacteria. Foods such as baco n and malt beverages can contain nitrosamines; there also is evidence that they form in the upper gastrointestinal tract. Research suggests nitrosamines may also be produced as disinfection byproducts, particularly as a result of chloramination of drinking water.



# T he final UCMR 2 rule maintains the basic program design of the original UCMR, building upon the structure established by the original rule for this cyclical program. The primary design changes between UCMR 1 and UCMR 2 include: (1) strengthening the Screening Survey statistical sample by increas ing the number of systems monitoring; (2) revising and clarifying the list of required “data elements”; and , (3 ) specifying both entry point and distribution system monitoring for certain contaminants. Other minor revis ions reflected “lessons learned” during UCMR 1.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 7 

# UCMR 2 monitoring requirements for PWSs varied according to system size. The three size categories under the program are “small” (serving 10,000 or fewer people ), “large” (serving between 10,001 and 100,000 people) and “very large” (serving more than 100,000 people).

UCMR 2 required all large and very large CWSs and NTNCWSs, plus a statistically repres entative national sample of 800 small CWSs and NTNCWSs, to monitor for the Assessment Monitoring contaminants. The sample of 800 small systems represents the approximately 62,000 small systems operating nationally. Additionally, EPA required monitoring of the 15 Screening Survey contaminants by all very large PWSs, 320 selected large PWSs, and 480 selected small PWSs. The Screening Survey sample of 800 small and large systems was designed to be representative of the approximately 65,000 small and large syst ems operating nationally. See Section 4.3.3 for more detail on national extrapolation of monitoring results based on the representative system sampling.
Both Assessment Monitoring and the Screening Survey had the same monitoring requirements for ground wa ter (GW) and surface water (SW) systems. Surface water and ground water under direct influence (GUDI) of surface water systems were required to sample for four consecutive quarters (per entry point to the distribution system) over a 12-month period, with samples collected 3 months apart. Ground water systems had to sample only twice (per entry point), 5 to 7 months apart within a 12-month period. EPA, in coordination with the states, assigned individual monitoring schedules (year and month of monitoring) to each PWS subject to UCMR 2.
Two categories of PWSs were exempt from UCMR 2 monitoring. First, PWSs that purchase their entire water supply from another PWS were not included since monitoring at these systems could result in double-counting of estimated population exposure (i.e., the PWSs selling water are also monitoring and reporting their contaminant occurrence findings). Second, transient non- community water systems (TNCWSs) were excluded since estimating contaminant exposure for transient populations can be difficult and inconclusive. The exclusion of these two categories of PWSs from UCMR 2 monitoring is consistent with the exclusion of the same two categories of PWSs from most compliance monitoring requirements. Sections 2.2 and 2.3 describe the PWSs that were required to conduct UCMR 2 monitoring. See Exhibit 2-2 for the fu ll breakdown of each program component by system size and source water type

. Note that the small and large systems were further subdivided into narrower categories for the purpose of constructing a stratified random sample. See Reference Guide for the Second Cycle of the Unregulated Contaminant Monitoring Regulation (UCMR 2) ( USEPA , 2006) for additional information about implementation of UCMR 2.



# 2.2 Assessment Monitoring

E PA maintained the same basic statistical design used for UCMR 1 for its UCMR 2 national representative sample of 800 small systems for Assessment Monitoring . The sample size was determined by a combination of statistical and budgetary considerations. A sample of 800 systems is more than the approximately 720 systems (659 CWSs and 61 NTNCWSs) needed to meet programmatic data quality objectives (DQOs) . It also enables the selection of at least two PWSs in each state to ensure a broad and diverse geographic coverage. The small system representative sample was designed to account for different system sizes, types of systems, sources of water supply, contaminants likely to be found, and geographic location (70 FR 49093;

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 8 

# USEPA, 2005). The UCMR 1 design was subjected to peer review and improved by recommendations of the peer reviewers, as we ll as suggestions made during the public comment and response process in developing UCMR 1. The details of the UCMR 1 design are included in USEPA (2001).

As with UCMR 1, UCMR 2 required that all large and very large CWSs and NTNCWSs that do not purchase all of their water from another system
, monitor their water for the presence of the 10 Assessment Monitoring contaminants.
A total of 4,140 systems (800 small, 2,942 large, and 398 very large) submitted Assessment Monitoring results.

Assessment Monito ring samples were collected at the entry point(s) to the distribution system (EPTDSs) (for systems with multiple EPTDSs, samples were required to be collected from every entry point 3 

# ) . PWSs were allowed to collect “raw source water” samples only in those instances where groundwater enters the distribution system untreated at the EPTDS, wa s a change from UCMR 1.



# 2.3 Screening Survey

I n addition to UCMR 2 Assessment Monitoring, UCMR 2 required monitoring for 15 Screening Survey contaminants. The UCMR 2 Screening Survey was designed to increase the statistical strength of the sampling results compared to the UCMR 1 Screening Survey design. This was accomplished in two ways. First, the UCMR 2 Screening Survey used a larger stratified random sample of appr oximately 800 systems
, as compared to 300 under UCMR 1. The sample size was derived from the same rationale as that for Assessment Monitoring, but the sample frame was expanded to include large systems. Second, this Screening Survey included a census of ve ry large PWSs. This approach minimizes the possibility of missing contaminant occurrence at the systems that serve the largest portion of the population while keeping the number of systems required to conduct the Screening Survey monitoring relatively smal l. No small systems were selected to participate in more than one component of UCMR 2 (i.e., if a small system was selected for Assessment Monitoring, it was excluded from possible selection f or the Screening Survey). The sample of 800 systems serving 100,000 or fewer people was divided uniformly

across 10 system size and water source strata (as was done for the prior Screening Survey under UCMR 1). For more detailed information on the selection of the Screening Survey PWSs, refer to the Unregulated Contaminant Monitoring Regulation (UCMR) for Public Water Systems Revisions; Proposed Rule (70 FR 49093; USEPA
, 2005).
For UCMR 1, the Screening Survey sample size was limited to 300 systems (120 large and 180 small PWSs). Screening Survey data from UCMR 1 were generally expected to provide only enough information for EPA to determine whether a contaminant should be elevated to future Assessment Monitoring. The resulting data of all systems combined were designed to be used for national estimates . Individual syst em strata had variance s that w ere too large to provide meaningful estimates. The increased sample size of the UCMR 2 Screening Survey enables

3 

## Ground water systems could limit monitoring to representative entry points if they had appropriate documentation and state approval.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 9 

# national estimates for each of the system size strata . A total of 1,198 systems (480 small, 320 large, and 398 very large) submitted Screening Survey results.

As for Assessment Monitoring, Screening Survey samples we re also collected at the EPTDSs for all Screening Survey contaminants. However, for those systems that utilize chemical disinfection, additional sampl es were collected for nitrosamines at the distribution system maximum residence time (DSMRT) sampling point associated with each plant/water source.

Exhibit 2-2 : Number of PWSs that Monitored Under UCMR 2

Size Category P opulation served Assessment Monitoring Systems . Screening Survey Systems . Total

.

. GW SW + GUDI GW SW + GUDI

.

. 25 to 500 104 5 80 80 269

. 501 to 3,300 259 48 80 80 467

. 3,301 to 10,000 255 129 80 80 544

Small 1 

## S ystems serving 25 to 10,000 people 618 182 240 240 1,280

. 10,001 to 50,000 1,239 1,246 75 2 

## (subset of the 1,239) 85 2 

## (subset of the 1,246) 2,48 5

. 50,001 to 100,000 135 322 76 2 

## (subset of the 135) 84 2 

## (subset of the 322) 457

Large 1 

## S ystems serving 10,001 to 100,000 people 1,374 1,568 151 2 

## (subset of the 1,374) 169 2 

## (subset of the 1,568) 2,94 2

Very Large S ystems serving
o ver 100,000 people 63 335 63 335 398

Total UCMR 2 Systems

. 2,055 2,085 454 744 4,6 20

1 

## F or the purpose of constructing stratified random samples , the small PWSs w ere grouped into three subcategories and the large PWSs were grouped into two subcategories

.

2 

## The number of systems included in these cells are excluded from row totals (as they are a subset of the systems conducting Assessment Monitoring)
, but are included in the column totals to show the overall total number of systems conducting Screening Survey monitoring.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 10 

# 3 UCMR 2 Data Description

T his section of the report describes the process of submitting, managing, and quality checking the UCMR 2 occurrence data. It also describes the assessment of the representativeness and completeness of the data set as well as various temporal, geographical, and other characteristics of the da ta.
The analyses presented in this report are based on the final UCMR 2 data set , which includes analytical results of water samples from all 4,620 systems that were expected to submit UCMR 2 data (100% compliance). To accommodate final (late) UCMR 2 rep orting, the data system remained open for submission of data through December 31, 2011. The final data set, including the sample data submitted through December 2011, is available on the UCMR website ( http://www.epa.gov/dwucmr/occurrence- data

- unregulated -contaminant-monitoring-rule#2 ). This document also provides detailed descriptions of EPA’s management and analysis of the data.



# 3.1 Data Submittal Process

T his section describes the process by which the UCMR 2 data were submitted by PWSs and laboratories.
Laboratories conducting UCMR sample analysis were also responsible for posting the sample analytical data to the Safe Drinking Water Accession and Revie w System (SDWARS). Access to SDWARS , which is the main database for upload, review, and storage of UCMR 2 data, is through the Central Data Exchange (CDX), EPA’s electronic reporting system. The CDX is the point of entry on the Environmental Information Ex change Network where PWSs, laboratories, states, and EPA submit, view, review, and (in the case of UCMR large systems) approve UCMR 2 occurrence data. Numerous security controls have been established to prevent unauthorized entry into the CDX and the SDWARS/UCMR storage system, and to prevent the potential loss of data or inappropriate transformations. CDX required users to register prior to being allowed access to data reporting and reviewing sections (only records from registered laboratories and systems could be uploaded into the database). In addition, the SDWARS/UCMR system has a number of electronic back -up provisions to minimize the risk of data being lost through tampering, system failure, or inadvertent deletion.
For the large systems, data were p osted directly to SDWARS by laboratories. PWSs accessed SDWARS to review the data and approve its release to EPA. Large PWSs had 60 days to review the data posted by their laboratories. After 60 days, if a PWS had not reviewed its UCMR 2 data, it was automatically approved and released to EPA (and concurrently to the state) as the system’s official UCMR 2 results.
EPA collected and reviewed occurrence data for small systems. EPA performed a thorough QC review of the data for small systems as part of the agency’s oversight of the contract laboratories performing sample collection and analyses. Small PWSs were authorized to review their data in SDWARS, but were not responsible for final data approval. The QC review was provided to states for review and comment.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 11 

# For all system sizes, w hen the EPA QC review was complete and the system’s 60- day review period had passed, the data were considered valid. D ata that passed final quality assessments were made available to the public through the National Contaminant Occurrence Database (NCOD), which is accessible through the EPA website.



# 3.2 Data Management and Quality Assurance

T his section describes how the UC MR 2 data were collected, maintained, and organized by EPA. QA/QC procedures are also described. Data discussed in this section include the water sample analytical data (monitoring results that define contaminant occurrence) and PWS inventory information ( data that define characteristics of the participating PWSs ). Exhibit 3-1 defines the data elements that were required to be provided with UCMR 2 sample results.

Exhibit 3-1 : UCMR 2 Required Data Elements

Data El ement Definition

Public Water System Identification (PWSID) Code 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. The same identification code must be used to represent the PWS identification for all current and future UCMR monitoring.

Public Water System Facility Identification Code An identification code established by the state or, at the state’s discretion, by the PWS, following the format of a 5

- digit number unique within each PWS for each applicable facility (i.e., for each source of water, treatment plant, distribution system, or any other facility associated with water treatment or delivery). The same identification code must be used to represent the facility for all current and future UCMR monitoring. Water Source Type The type of source water that supplies a water system and sampling location . Systems must report one of the following codes for each sampling location:

SW Surface water (to be reported for water facilities that are served all or in part by a surface water source at any time during the 12

- month period).

GW Ground water (to be reported for water facilities that are served entirely by a ground water source).

GU Ground water under the direct influence of surface water (to be reported for water facilities that are served all or in part by ground water under the direct influence of surface water at any time during the 12

- month sampling period), and are not served at all by surface water during this period. MX Any combination of the three water types listed above.

Sampling Point Identification Code An identification code established by the state, or at the state’s discretion, by the PWS, that uniquely identifies each sampling point. Each sampling code must be unique within each applicable facility, for each applicable sampling location (i.e., entry point to the distribution system or distribution system sample at maximum residence time). The sa me identification code must be used to represent the sampling location for all current and future UCMR monitoring. Sampling Point Type Code A code that corresponds to the location of the sampling point

. EP Entry point to the distribution system. MR Dist ribution system sample at maximum residence time.

Disinfectant Residual Type The type of disinfectant in use at the time of UCMR sampling to maintain a residual in the distribution system for each Screening Survey sampling point. To be reported by systems required to conduct Screening Survey monitoring. Systems must report using the following codes for each Screening Survey sampling location (i.e., EP, MR): CL Chlorine.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 12 Data El ement Definition

CA Chloramine. OT All other types of disinfectant (e.g., chlorine dioxide). ND No d isinfectant used. Sample Collection Date The date the sample is collected, reported as 2

- digit month, 2

- digit day , and 4

- digit year (i.e., 01152008).
Sample Identification Code An alphanumeric value up to 30 characters assigned by the laboratory to uniquely identify containers, or groups of containers, containing water samples collected at the same sampling location for the same sampling date. Contaminant The unregulated contaminant for which the sample is being analyzed. Analytical Method Code The identification code of the analytical method used. Sample Analysis Type The type of sample collected and/or prepared, as well as the fortification level. Permitted values include: FS Field sample; sample collected and submitted for analysis under this rule.

LFSM Laboratory fortified sample matrix; a UCMR field sample with a known amount of the contaminant of interest added.

LFSMD Laboratory fortified sample matrix duplicate; duplicate of the laboratory fortified sample matrix.

CF Concentration fortif ied; reported with sample analysis types LFSM and LFSMD, the concentration of a known contaminant added to a field sample.

Analytical Result

— Sign A value indicating whether the sample analysis result was: (<) “less than” means the contaminant was not detected, or was detected at a level below the Minimum Reporting Level. (=) “equal to” means the contaminant was detected at the level reported in “Analytical Result

— Value.” Analytical Result

— Value The actual numeric value of the analytical results for: f ield samples; laboratory fortified matrix samples; laboratory fortified sample matrix duplicates; and concentration fortified.
Laboratory Identification Code The code, assigned by EPA, used to identify each laboratory. The code begins with the standard tw o- character state postal abbreviation; the remaining five numbers are unique to each laboratory in the state.

Sample Event Code A code assigned by the PWS for each sample event. This will associate samples with the PWS monitoring plan to allow EPA to track compliance and completeness. Systems must assign the following codes:

SE1 Represents samples collected to meet the UCMR monitoring requirement for the first sampling period (all source types).

SE2 Represents samples collected to meet the UCMR monitoring requirement for the second sampling period (all source types).

SE3 Represents samples collected to meet the UCMR monitoring requirement for the third sampling period (SW and GU sources only).

SE4 Represents samples collected to meet the UCMR m onitoring requirement for the fourth sampling period (SW and GU sources only).



# UC MR 2 data that were ready for EPA review were extracted on a monthly basis from SDWARS via the CDX. EPA reviewed all UCMR 2 data that had already passed the laboratory and PWS reviews. In addition, the SDWARS database was developed with several automated data quality criteria checks designed into the database structure so only data that passed QA measures could be successfully imported into the database. The database conducts an automated data review and flag s questionable records. Reasons for flagging records include, but are not limited to , missing required fields, or records that are duplicates (i.e., having the same PWSID,

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 13 

# PWS Facility ID, Sampling Point ID, contaminant, and sample collection date). 4 

# In addition, the database includes a “range check” that identifies data outliers or possible unit problems. For example, any reported contaminant concentration values that are a thousand-fold lower than most other low contaminant concentration values would be flagged and investigated, since such significantly lower results likely reflect an analytical unit conversion problem (mg/L versus μg/L) in the original raw data.

For more details on the data quality review applied to the small system data, refer to the Standard Operating Procedure: NCOD Data Import for Small Systems for the Second Cycle of the Unregulated Contaminant Monitoring Regulation, Revision 1.0 ( USEPA , 2009). For m ore details on the data quality review of the large system occurrence data, refer to the Quality Assurance Project Plan for the Implementation of the Unregulated Contaminant Monitoring Regulation ( USEPA , 2003b).



# 3.3 Assessments of Data Representativeness and Completeness

T o ensure that the UCMR 2 data and occurrence estimates dependably reflect national conditions, the representativeness and completeness of the UCMR 2 contaminant sample data were assessed. This section describes how the UCMR 2 data were asse ssed for representativeness and completeness.

3.3.1 Data Representativeness

Assessment Monitoring - Small Systems (Serving ≤ 10,000 Persons)

The UCMR 2 small system sampling design incorporated a stratified sampling approach to enable statistically valid nat ional occurrence analyses according to system size (based on population served) and water source type ( e.g. surface water , ground water). 5 

# This stratified, population- weighted, random selection process is the same process used for UCMR 1 and is described in detail in the Statistical Design and Sample Selection for the Unregulated Contaminant Monitoring Regulation ( USEPA
, 2001). Statistical design and program DQOs, as well as cost and scheduling considerations resulted in a sample design that selected 800 small PWSs that collectively provide nationally representative contaminant occurrence data.
EPA identified DQOs for the representative sample of small systems to include the following: data should provide unbiased nationa l exposure estimates; and margins of error must be kept to ±1% with 99% confidence for CWSs and ±2.5% with 95% confidence for NTNCWSs. If the estimated percentage of PWSs with a detection is 1%, EPA must be able to state with 99% confidence that the true exposure fraction is between 0% and 2%. In other words, if the sampling plan were to be repeated many times, the true occurrence and exposure values would fall within the 1% margin of error around the estimate in 99% of all cases.

4 

# Note that some duplicate records are legitimate and are retained in the data set. If a system sampled and got a high detection of a contaminant, and then re

- sampled, both results are retained in the database. At the time of data analysis, the largest detection value would be used for all occurrence analyses.
5 

# The number of NTNCWSs designated and selected for monitoring does not support a statistically valid analysis of only NTNCWSs.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 14 

# M eeting the representativeness objective require d that the designated sample of small systems conducting monitoring be stratified and implemented correctly. In a small number of cases, the originally selected small systems could not participate (due to closing, change in status, etc.)

. Replacement systems were statistically selected in the event that the original (or first or second replacement) system could not participate.

Assessment Monitoring - Large and Very Large Systems (Serving > 10,000 Persons)
A census, such as that required for all eligible large systems under UCMR 2 Assessment Monitoring, is by definition the most representative type of sample design. All PWSs serving more than 10,000 people that submitted Assessment Monitoring UCMR 2 data.

Screening Survey - Small and Large Systems (Serving ≤ 100,000 Persons)
Screening Survey systems were selected from all large and small system subcategories
, with each of the five sub categories given equal importance. 6 

# Therefore, 160 systems were selected from each size sub category . Within each subcategory, selected systems were distributed evenly between surface water and ground water systems wherever possible.

Screening Survey - Very Large Systems (Serving > 10,000 Persons)
All PWSs serving more than 100,000 people (approximately 400 systems) were required to conduct Screening Survey monitoring.

3.3.2 Completeness
The DQO for completeness of the occurrence data has two components: that 90% of data submitted are accept able (i.e., conform to QC criteria with all data elements present and accurate) , and that acceptable data are obtained from 82.375% of selected PWSs. Although, as designed, all selected PWSs (i.e., 100%) are required to collect and report UCMR 2 occurrence data, in practice some samples may not be collected and some results may not be reported. This DQO provides for adequate data quality for end

- use applications while recognizing the practical realities of PWS monitoring that some required data are not generated and/or reported. The DQO to obtain acceptable data from 82.375% of PWSs is based on a calculation of the minimum requirements to produce national ly representative estimate s of PWS contaminant occurrence with a 99% confidence interval and a 1% margin of error.

All (100%) of the 4,620 small, large, and very large PWSs required to participate in UCMR 2 collected and report ed UCMR 2 occurrence data , s urpass ing the DQO goal of 82.375%. Furthermore, as described earlier, the SDWARS database contained several data quality criteria checks
, so only data that passed QA measures were successfully imported into the database. Thus, the DQO of 90% for acceptable data was also surpassed

.

6 

# Unlike Assessment Monitoring, system s election for the Screening Surve y was not proportionately weighted by population serve d or by the proportion of systems in each size category. If the sample was weighted by population served, a disproportionate number of large systems would be included in the Screening Surveys. If the sa mple were weighted by the number of systems in each size category, a disproportionate number of small systems would be represented.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 15 

# 3.4 Additional Data Management Considerations

A dditional QA/QC measures were applied to the UCMR 2 data set to evaluate other quality aspects of the occurrence data and system inventory data. The following section addresses data management steps taken with the UCMR 2 systems’ population- served values asthey relate to consecutive systems, seller/purchaser relations, and the resulting potential doublecounting of populations served by systems.

3.4.1 Population Adjustments
As described in Section 2.1, all “purchased systems” (systems purchasing 100% of thei r water from other systems) were exempt from UCMR 2 monitoring. However, exclusion of these systems meant the populations served by those systems would also be excluded from the exposure estimates conducted for the UCMR 2 analyses. Therefore, the populations served by the purchased systems were assigned to the systems they purchased from (the “wholesale systems”). To do this, EPA compiled a list of all purchased systems that sell water directly to the consumer. EPA then id entified the wholesale system (s) from which each system on the list purchases water. If a purchased system purchased 100% of its water from a single wholesale system, the population served by each purchased system was assigned to the wholesale system and added to wholesale system’s total population served . The contaminant occurrence measures that include these wholesale systems with their “adjusted” population- served values include the population served by the purchased systems.
A total of 386 purchased s ystems purchase water from more than one seller. To avoid double-counting in these cases , the population served by the purchasing systems was assigned fractionally to its wholesalers. Since no data were available on the relative quantities of water purchas ed from the different wholesalers , a uniform distribut ion was assumed . 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 complian ce occurrence data from that purchasing system is excluded from the occurrence analyses because it is a purchased system; however, one-third of its population served (60,300 ÷ 3 = 20,100) is assigned to each of the three systems from which it purchases wat er. This way, the population served by purchased systems is included in the analyses and considerations for UCMR 2.

3.4.2 Temporal Information

The UCMR 2 program was designed with concerns about temporal variability in mind. The study design addressed tempora l variability in contaminant occurrence by defining a vulnerable period (i.e., the season of greatest likelihood of contaminant occurrence ; generally the months of late spring and early summer, which are characterized by high volumes of surface water runoff and ground water recharge) . At least one UCMR 2 sample at each applicable sampling point were required to be collected during that period. Each system was required to monitor for one year (12 consecutive months) during the three years of UCMR 2 monitoring (2008 – 2010). For small systems , approximately one-third were scheduled to conduct monitoring in each of the three years ; with UCMR 2 schedules staggered to ensure that results

we re collecte d from every month in every part of the country. Large systems could conduct their 12 consecutive months of monitoring anytime during the UCMR 2 period. Like small systems,

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 16 

# their monitoring schedules were spread throughout the year and included one monitoring period during their most vulnerable season. By staggering system monitoring schedules and requiring monitoring during at least on e vulnerable period, EPA ensured that the UCMR 2 results reflected multiple seasons and multiple years of climatic conditio ns throughout the country and we re not directly affected (or biased) by weather conditions of a single season, year, or geographic region.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 17 

# 4 Description of Stage 1 Analytical Method

T he Stage 1 analysis consists of simple, non- parametric measures of occurrence using the UCMR 2 data. Based on the occurrence findings of the Stage 1 analyses, among other considerations, more statistically rigorous parametric analyses for select contaminants can be conducted. These parametric occurrence analyses are referred to as Stage 2 analyses. This two

stage analytical approach has been peer reviewed and used to conduct other occurrence analyses that supported Regulatory Determination 1 and 2 (USEPA, 2002; USEPA, 2008a ) an d Six

- Year Review (USEPA, 2003a). This section is a discussion of the Stage 1 analyses. Stage 2 analysis is briefly described in Section 1 of this document. The occurrence estimates conducted using UCMR 2 data and presented in Section 5 of this document involve Stage 1 analyses only.



# 4.1 Stage 1 Analysis

T he basic Stage 1 analytical methodology is a conservative approach: occurrence measures are based on actual counts of whether a PWS has at least one sample analytical result greater than a specified concentration threshold. This is roughly analogous to a measure based conservatively on peak contaminant occurrence (i.e., when a system’s occurrence is represented by the maximum concentration even if numerous other samples collected by the system were non-detections or had lower concentrations). The Stage 1 statistical analys is of the UCMR 2 data consists of direct counts and descriptive statistics of analytical sample data for each of the monitored contaminants. The analytical sample data define the presence or absence of a contaminant relative to the analytical method minimu m reporting level (MRL) and, if present, the concentration of the detected contaminant.
These analyses were conducted to characterize occurrence by samples, systems, and populations served by systems. At the sample level, occurrence measures included: th e number and percent of samples for each contaminant with analytical detections; and the minimum, median, maximum, 90th and 99th percentile concentration values of those detections. Systemlevel occurrence measures include the number and percent of systems with one or more analytical detections by contaminant. At the level of p opulations served
, occurrence measures include the number and percent of customers served by systems with one or more analytical detections by contaminant.

All occurrence analyses presented in this report were stratified by water system source water type . The stratification by source water type was consistent with source water type classification protocols used for past efforts (i.e., systems using GUDI and those using a mix of grou nd water and surface/GUDI sources were classified as surface water systems).
The Stage 1 approach incorporates another conservative assumption: if a detection occurs in a single entry point in a system, then the entire population served by the system is exposed to the detected contaminant (i.e., even if there are other entry points with no detections that might dilute the concentration found in the single entry point sample). For example, if a PWS serves a population of 10,000 and finds a detection of a U CMR 2 contaminant in one of its two entry points on one occasion, the Stage 1 analytical methodology would estimate that the entire population served by the system (i.e., all 10,000 persons) was exposed to the maximum detected levels of the contaminant.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 18 

# I n reality, many systems get water from multiple water sources (a mix of multiple wells, or more than one surface water source, or a combination of ground water and surface water

sources ). In systems with multiple water sources or water intakes, contaminan t occurrence in one source or entry point does not necessarily mean occurrence in all sources or entry points that distribute water to consumers.
Entry point- level occurrence measures can also be part of the Stage 1 analyses. EPA did not perform entry point-level analyses on any of the contaminants evaluated in this report.



# 4.2 Threshold Evaluations

E PA performed occurrence evaluations of UCMR 2 contaminants relative to multiple concentration thresholds. One occurrence analysis was conducted relative to th e MRL for each UCMR 2 contaminant . In this analysis, any concentration equal to or greater than the MRL was considered an analytical detection. Evaluations of occurrence relative to the MRL provide a baseline measure of occurrence.

Detections of UCMR 2 co ntaminants were also evaluated relative to two other concentration thresholds: the Health Reference Level (HRL) and one -half the HRL (1⁄2 HRL). The HRL is an EPA -defined risk -derived concentration for evaluating contaminant occurrence based on health effects information. 7 

# There are two general approaches to the derivation of an HRL. One approach is used for chemicals that cause cancer and exhibit a linear response to dose
, and the other applies to non- carcinogens and carcinogens evaluated using a non

- linear approach

. See Appendix B of the Protocol for the Regulatory Determination 3 USEPA ( 2014a) for detailed discussion of HRLs, including descriptions of the linear and non- linear approaches to HRL derivation. Conducting occurrence assessments relative to the he alth -based thresholds in addition to the MRL gives additional information on the degree as well as the frequency of contaminant occurrence and helps to better characterize the distribution of occurrence.

Exhibit 4-1 : Minimum Reporting Levels (MRLs) and Health Reference Levels (HRLs) for UCMR 2 Contaminants

Contaminant MRL (μg/L) HRL 1 

## (μg/L)

. Assessment Monitoring Contaminants

. BDE

- 47 0.3 -- BDE

- 99 0.9 -- BDE

- 100 0.5 -- BDE

- 153 0.8 -- Dimethoate 0.7 15 .4

7 

# EPA evaluates the best available, peer

- reviewed assessments and studies to characterize the human health effects that may result from exposure to individual contaminants when found in drinking water. Based on this characterization, the a gency estimates an HRL for each contaminant. HRLs are not final determinations of the level of a contaminant in drinking water that is necess ary to protect any particular population and are derived prior to the development of a complete exposure assessment.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 19 Contaminant MRL (μg/L) HRL 1 

## (μg/L) 1,3

- Dinitrobenzene 0.8 0 .7
HBB 0.7 -- RDX 1 21 Terbufos sulfone 0.4 0.35
TNT 0.8 --

. Screening Survey Contaminants

. Acetochlor 2 1 Acetochlor ESA 1 1 Acetochlor OA 2 1
Alachlor 2 2 2


## Alachlor ESA 1 0.4 Alachlor OA 2 0.4
Metolachlor 1 700 Metolachlor ESA 1 700 Metolachlor OA 2 700
NDBA 0.004 0.03 3


## NDEA 0.005 0.0004
NDMA 0.002 0.0006
NDPA 0.007 0.007
NMEA 0.003 0.003 3


## NPYR 0.002 0.00 2

1 

## Note: "--" indicates that there is no HRL for this contaminant. These UCMR 2 contaminants are not on CCL 3.
2 

## Alachlor is a regulated drinking water contaminant with a Maximum Contaminant Level (MCL) of 2 μg/L.
3 

## NDBA and NMEA are not on CCL 3; however, they do have HRLs
, since they are being evaluated by EPA alongside the other nitrosamines, as part of a nitrosamine group

.



# 4.3 Additional Considerations for Stage 1 Analysis

4.3.1 Ground Water and Surface Water Comparisons
Given the different sampling schedules of ground water systems (two samples per year) and surface water systems (four samples per year), care must be taken regarding any sample

level comparative analyses between the two source water types. For example, if the true rate of detection for a given contaminant were identical for both ground water and surface water systems, one would expect to see roughly twice the number of detections in the surface water systems simply because surface water systems collect twice as many samples. Estimating the percentage of detections by source water type (i.e., dividing the number of detections by number of samples taken for a particular source type ) corrects for this difference and provides a fair comparison of detection r ates across surface water and ground water systems. System

- level and population- served -level analyses also account for the different sampling frequencies.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 20 

# 4.3.2 Large System and Small System Totals
When presenting the Stage 1 Analyses, it is sometimes useful t o summarize the occurrence of a contaminant as a single number or percentage. When doing so for the Assessment Monitoring contaminants, however, consideration should be given to the distinction between analytical results from the small system sample and la rge system census. Simply adding the number of both small and large systems’ detections may undercount the actual number of detections at the nation’s small systems because of the differences in UCMR 2 monitoring for small and large systems (see Section 2.1). While such simple summaries accurately present the UCMR 2 monitoring results themselves, reasonable estimates of national contaminant occurrence require national extrapolation of the small system Assessment Monitoring occurrence data. The se same consid eration s are applicable for the Screening Survey contaminants when summarizing occurrence as a single number or percentage using analytical results from the sample of small and large systems and the census of very large systems.

4.3.3 Extrapolation of the Resu lts

Under UCMR 2 Assessment Monitoring, the 800 small systems (serving 10,000 or fewer people ) selected to conduct monitoring were a stratified, random, statistically

- weighted sample of the nation’s small systems. These 800 small systems were chosen to represent the distribution of small system characteristics found at the national level. Consequently, contaminant occurrence findings for those 800 UCMR 2 small systems are representative of occurrence at the approximately 62,000 small systems operating nationally. 8 

# Moreover, the 2.7 million persons served by the 800 UCMR 2 sampled systems are representative of the approximately 47 million served by all small systems nationally.

For the UCMR 2 Screening Survey, monitoring was required by 320 large PWSs servi ng 10,001-100,000 people, and 480 small PWSs serving 10,000 or fewer people. These 800 small and large systems were chosen to represent the distribution of small and large system characteristics found at the national level. Thus, Screening Survey occurrence findings UCMR 2 are representative of occurrence at the approximately 65, 000 small and large systems operating nationally, and the approximately 130 million served by those small and large systems.
To calculate national extrapolations, the percent of systems (or of populations served by systems) estimated to exceed a specified threshold is multiplied by the total number of systems (or population served) in the nation (see Exhibit 4-2 ). Estimates of national system and population-served numbers were developed from a combination of EPA’s Safe Drinking Water Information System (SDWIS), the Community Water System Survey (CWSS), and the UCMR

. Analogous national extrapolations can also be made for the occurrence results of the Screening Survey sma ll and large systems. However, for the Screening Survey , only aggregated national estimates are appropriate because the error margin may be too large in small subcategories to be conclusive, particularly in cases where no detections occur. Monitoring resul ts are carefully analyzed to assess the possible implications of results.

8 

# This national estimate of systems and population served by systems was developed from EPA’s Safe Drinking Water Information System (SDWI S), the Community Water System Survey (CWSS), and UCMR.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 21 

# Exhibit 4-2 presents results from NDMA to illustrate how system

- level estimates of national contaminant occurrence are calculated by extrapolation of UCMR 2 Screening Survey monitoring results for small and large systems. To estimate the national number of small ground water systems that are e xpected to have detections, the percentage of systems of that source water type/system size strata with detections of the contaminant (in this example, approximately 4.17%) is multiplied by the estimated total number of small ground water systems in the nation (57,818 systems). The result is an estimate of 2,409 small ground water systems that are expected to have detect able concentrations of the contaminant (assuming monitoring protocols similar to that used under UCMR 2). Note that the calculations used to pro duce the national estimates involve more significant digits than are shown in the table. Thus, due to rounding, some calculations (including the one above) may appear to be incorrect . Comparable calculations are used to estimate the population served nationally by systems in that source water type/system size category, and to make the corresponding extrapolations in the other source water type/system size categories. The national estimates for “All Small Systems” and “All Large Systems” were calculated by summing extrapolated ground water and surface water results in each category

.
Exhibit 4-2 : Example Calculation of National Estimates (Extrapolations) for UCMR 2 Small and Large Systems (serving ≤ 100,000 peo ple) for Screening Survey Contaminants

Water Type National Inventory 1



## . Percentage ≥ MRL (based on UCMR 2) . National Estimate

.

. Systems Population Systems Population Systems Population

. . . Small Systems (serving ≤ 10,000 people)

. . . Ground Water 57,818 37,685,557 4.17% 4.75% 2,409 1,790,869 Surface Water 3,866 8,928,745 30.83% 39.25% 1,192 3,504,746 All Small Systems 61,684 46,614,302 17.50% 23.60% 3,601 5,295,615

. . . Large Systems (serving 10,001 - 100,000 people)

. . . Ground Water 1,506 38,870,272 8.61% 11.23% 130 4,363,960 Surface Water 1,366 44,536,172 34.32% 37.51% 469 16,707,724 All Large Systems 2,872 83,406,444 22.19% 25.18% 598 21,071,684

1 

### National inventory data for systems and populations were developed from EPA’s SDWIS, the CWSS, and UCMR.



# 4.3.4 Stage 1 Analyses and the Statistically-Weighted Sample of Small Systems
The Stage 1 occurrence analysis consists of simple, non- parametric, descript ive statistics based directly upon the contaminant occurrence data. The 800 small systems required to conduct UCMR 2 Assessment M onitoring were selected as a statistically -weighted (primarily populationweighted) stratified sample, in a similar fashion tha t 800 small systems were selected for UCMR 1 monitoring. Because of the difficulties in calculating the statistical weighting parameters, the UCMR 1 occurrence findings did not incorporate adjustments for the statistically

- weighted sample selection of the UCMR 1 small systems. However, a sensitivity analysis was conducted on the 800 UCMR 1 small systems to address the issue of adjusting the occurrence findings to account for the statistically- weighted sample of small systems. At every detection level, the a nalysis found no significant statistical difference between estimates of the weighted and unweighted means (USEPA, 2008b ). Since the 800 UCMR 2 small systems were

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 22 

# selected in a similar fashion, it is expected that there would be no significant statistical difference between estimates of the weighted and unweighted means for UCMR 2 as well.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 23 

# 5 Stage 1 Occurrence Estimates

T his section presents summary Stage 1 occurrence findings for the 25 contaminants monitored under UCMR 2 . The following exhibits, evaluated together with the other analytical results included within this report and report appendices, provide a multi- faceted presentation of the frequency, degree, and distribution of the occurrence of those contaminants as sampled and reported under UCMR 2.

Basic occurrence information for all 25 UCMR 2 contaminants is summarized in Exhibit 5-1 and Exhibit 5-2. Exhibit 5 -1 shows sample-level results, including minimum, median, and maximum concentrations. Exhibit 5-2 shows system-level results, including data on populations served by systems with detections. Separate contaminant -specific sections and exhibits follow which provide more details on the occurrence results. These more detailed occurrence results are included only for contaminants with at least one detection.

In the final UCMR 2 data set , 13 of the 25 contaminants were not detected in any of the large or small systems that sampled under UCMR 2. Eight of the 13 contaminants with no detections were from the Assessment Monitoring component: BDE

- 47, BDE -99, DBE-100, DBE -153, dimethoate, 1,3-dinitrobenzene, HBB, and TNT. The remaining five contaminants with no detections were from the Screening Survey component: a cetochlor, acetochlor OA, alachlor, alachlor OA, and NDPA. One of the 25 contaminants, terbufos sulfone, had only a single detection. The remaining 11 UCMR 2 contaminants had multiple detections in small and/or large systems.
Additional occurrence findings are contained in Appendi ces A, B, and C. Appendix A provides detailed occurrence findings at the level of samples, systems, and population served for all UCMR 2 contaminants (including contaminants that had no detections). In Appendix B, the number of sy stems that monitored for each UCMR 2 contaminant, the number of sample s taken at those systems , and the population served by the systems are listed and broken out by state

. Appendix C includes more detailed occurrence numbers for the 12 UCMR 2 contaminants with detections , including summary statistics by source water type and system size and the number and percentage of samples that exceeded the HRL.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 24 

# Exhibit 5-1 : Summ ary of Stage 1 Occurrence Results for 10 Assessment Monitoring Contaminants and 15 Screening Survey Contaminants : Sample

- Level Results

Contaminant

. Samples

. . Detected Concentration

.

. Number of Samples Detections

. Minimum (μg/L) Median (μg/L) Maximum (μg/L)

. . Number Percent

. . .

. . . Assessment Monitoring Contaminan ts

. . . BDE

- 47 32,149 0 0.00% ND ND ND
BDE

- 99 32,149 0 0.00% ND ND ND
BDE

- 100 32,1 49 0 0.00% ND ND ND
BDE

- 153 32,1 39 0 0.00% ND ND ND
Dimethoate 32,150 0 0.00% ND ND ND 1,3

- Dinitrobenzene 32,15 2 0 0.00% ND ND ND
HBB 32,143 0 0.00% ND ND ND
RDX 32,150 4 0.01% 1 1. 1 1.1
Terbufos sulfone 32,149 1 0.00 3% 0.42 0.42 0.42
TNT 32,151 0 0.00% ND ND ND

. . . Screening Survey Contaminants

. . . Acetochlor 11,193 0 0.00% ND ND ND
Acetochlor ESA 11,157 2 0.02% 1.10526 1.15263 1.2
Acetochlor OA 11,157 0 0.00% ND ND ND
Alachlor 11,193 0 0.00% ND ND ND
Alachlor ESA 11,156 5 0.0 4% 1 1.2 1.3
Alachlor OA 11,157 0 0.00% ND ND ND
Metolachlor 11,192 3 0.03% 1.152 1.4 2.73235
Metolachlor ESA 11,157 52 0.47% 1 1.4413 1 3.95455
Metolachlor OA 11,157 3 0.03% 2.502 3.078 3.539
NDBA 18,101 9 0.05% 0.004 0.00666 0.02062
NDEA 18,096 46 0.2 5% 0.005 0.007 0.1
NDMA 18,098 1,861 10.28% 0.002 0.004 0.63
NDPA 18,107 0 0.00% ND ND ND
NMEA 18,101 3 0.02% 0.0036 0.0045 0.0049
NPYR 18,101 41 0.23% 0.00207 0.0039 0.0238

NOTE: “ND“ indicates no detection of contaminant.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 25 

# Exhibit 5-2 : Summary of Stage 1 Occurrence Results for 10 Assessment Monitoring Contaminants and 15 Screening Survey Contaminants : System

- Level Results

Contaminant

. Systems

. . Population S erved

.

. Number of Systems Systems with Detection(s) . Total Population

Served by Systems Population Served by Systems with Detection(s) .

. . Number Percent

. Number Percent

. . . Assessment Monitoring Contaminant s

. . . BDE

- 47 4,140 0 0.00% 229,237,740 0 0.00%
BDE

- 99 4,140 0 0.00% 229,237,740 0 0.00%
BDE

- 100 4,140 0 0.00% 229,237,740 0 0.00%
BDE

- 153 4,140 0 0.00% 229,237,740 0 0.00%
Dimethoate 4,140 0 0.00% 229,237,740 0 0.00% 1,3

- Dinitrobenzene 4,139 0 0.00% 229,225,740 0 0.00%
HBB 4,140 0 0.00% 229,237,740 0 0.00%
RDX 4,139 3 0.07% 229,225,740 96,033 0.04%
Terbufos sulfone 4,140 1 0.02% 229,237,740 44,600 0.02%
TNT 4,139 0 0.00% 229,225,740 0 0.00%

. . . Screening Survey Contaminants

. . . Acetochlor 1,198 0 0.00% 157,219,620 0 0.00%
Acetochlor ESA 1,198 2 0.17% 157,219,620 3,832,155 2.44%
Acetochlor OA 1,198 0 0.00% 157,219,620 0 0.00%
Alachlor 1,198 0 0.00% 157,219,620 0 0.00%
Alachlor ESA 1,198 3 0.25% 157,219,620 3,910,398 2.49%
Alachlor OA 1,198 0 0.00% 157,219,620 0 0.00%
Metolachlor 1,198 3 0.25% 157,219,620 107,510 0.07%
Metolachlor ESA 1,198 19 1.59% 157,219,620 5,873,985 3.74%
Metolachlor OA 1,198 1 0.08% 157,219,620 1,045,522 0.67%
NDBA 1,198 5 0.42% 157,219,620 1,685,983 1.07%
NDEA 1,198 26 2.17% 157,219,620 11,232,194 7.14%
NDMA 1,198 324 27.05% 157,219,620 65,311,764 41.54%
NDPA 1,198 0 0.00% 157,219,620 0 0.00%
NMEA 1,198 3 0.25% 157,219,620 4,480 0.003%
NPYR 1,198 21 1.75% 157,219,620 7,431,551 4.73%

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 26 

# 5.1 Assessment Monitoring Contaminants

T his section presents summaries of occurrence results for Assessment Monitoring contaminants with at least one detection. In the final UCMR 2 data set , only 2 of the 10 Assessment Monitoring contaminants had at least one detection – RDX and terbufos sulfon e. See Exhibit 2-1 for the list of Assessment Monitoring contaminants, and their applicable methods and MRLs. The following two sections present detailed occurrence findings on those contaminants. The remaining eight Assessment Monitoring contaminants did not have any detections (BDE

- 47, BDE -99, BDE-100, BDE-153, dimethoate, 1,3-dinitrobenzene, HBB, and TNT); s ee Exhibit 5-1, Exhib it 5 -2, and Appendix A. The number of systems and samples, by state, are included for all 10 Assessment Monitoring contaminants in Appendix B.

5.1.1 RDX
As indicated in Appendices A and B, under UCMR 2 Assessment Monitoring 32,150 samples of RDX were collected from 4,13 9 PWSs . Of these, 4 samples (0.01%) had analytical detections of RDX at or above the MRL of 1 μg/L. The maximum detected concentration of RDX was 1.1 μg/L and the median value was also 1.1 μg/L. Appendix C includes m ore detailed occurrence numbers for RDX, such as summary statistics by source water type and system size and the number and percentage of samples with detections exceeding the HRL.
The four RDX detections occurred in 3 large surface water systems (0.10%) in 2 states (Tennessee and Texas). These systems served a combined population of 96,033 people, or 0.11%, of the national total population served by water systems of the same size. The percentage of all small, large, and very large UCMR 2 Assessment Monit oring systems with at least one detection of RDX was 0.07%. A summary of the number of systems with RDX detections and the population served by them is presented in Exhibit 5-3.
The design of the UCMR 2 Assessment Mon itoring enables extrapolation of national estimates of occurrence of contaminants detected in small water systems (see Section 4.3.3). Occurrence results from the large and very large systems are already nationally representative so national extrapolations are not necessary. These findings suggest that an estimated 3 PWSs serving approximately 96,000 customers nationally have RDX detections.

Exhibit 5-3: RDX National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 618 1,790,743 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 182 878,262 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 27 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

All Small Systems 800 2,669,004 0 (0%) 0 (0%) 61,684 46,614,302 0 (0%) 0 (0%)

. . . . Large Systems (serving 10,001 - 100,000 people)

-- CENSUS

. . . .

Ground Water 1,373 34,816,693 0 (0%) 0 (0%) 1,373 34,816,693 0 (0%) 0 (0%)

Surface Water 1,568 49,758,358 3 (0.19%) 96,033 (0.19%) 1,568 49,758,358 3 (0.19%) 96,033 (0.19%)

All Large Systems 2,941 84,575,051 3 (0.1%) 96,033 (0.11%) 2,941 84,575,051 3 (0.1%) 96,033 (0.11%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)
All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 4,139 229,225,740 3 (0.07%) 96,033 (0.04%) 65,023 273,171,037 3 (0.005%) 96,033 (0.04%)

1 

### National estimates for the small systems are extrapolations, generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages and national system/population inventory numbers for PWSs developed from EPA’s SDWIS, th e CWSS, and UCMR. National estimates for the large and very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all large and very large systems were required to conduct UCMR 2 Assessment Monitoring. Due to rounding, some calculations may appear to be incorrect

.



# R DX was evaluated relative to an HRL of 21 μg/L. None of the RDX detections exceeded the one-half HRL (10.5 μg/L ) or the full HRL (21 μg/L); thus no occurrence tables relative to th e HRL are included below.

5.1.2 Terbufos Sulfone
As indicated in Appendices A and B, under UCMR 2 Assessment Monitoring 32,149 samples of terbufos sulfone were collected from 4,140 PWSs . Of these, a single sample (0.003% of all samples) had an analytical detection of terbufos sulfone at or above the MRL of 0.4 μg/L (therefore above the HRL) . The single detected concentration of terbufos sulfone was equal to 0.42 μg/L. Appendix C includes more detailed occurrence numbers for terbufos sulfone, such as summary statistics by source water typ e and system size and the number and percentage of samples with detections exceeding the HRL.
The terbufos sulfone detection occurred in a single large ground water system (0.02% of all systems sampled for terbufos sulfone) in the State of New York. This system served a population of 44,600 people or 0.05% of the national total population served by water systems of

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 28 

# the same size. The percentage of all small, large, and very large UCMR 2 Assessment Monitoring systems with at least one detection of terbufos sulfone was 0.02%. A summary of the number of systems with detections and the population served by them is presented in Exhibit 5-4.
As described previously, the design of the UCMR 2 Assessment Monitoring enables national extrapolation of estimates of contaminant occurrence in small water systems (see Section 4.3.3). Occurrence results from the large and very large systems are already nationally representative so national extrapolations are not necessary. These fin dings suggest that one PWS serving approximately 44,600 nationally has detected terbufos sulfo ne

.
Exhibit 5-4: Terbufos Sulfone National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 618 1,790,743 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 182 878,262 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 800 2,669,004 0 (0%) 0 (0%) 61,684 46,614,302 0 (0%) 0 (0%)

. . . . Large Systems (serving 10,001 - 100,000 people)

-- CENSUS

. . . .

Ground Water 1,374 34,828,693 1 (0.07%) 44,600 (0.13%) 1,37 4 34,828,693 1 (0.07%) 44,600 (0.13%)

Surface Water 1,568 49,758,358 0 (0%) 0 (0%) 1,568 49,758,358 0 (0%) 0 (0%)

All Large Systems 2,942 84,587,051 1 (0.03%) 44,600 (0.05%) 2,94 2 84,587,051 1 (0.03%) 44,600 (0.05%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 4,140 229,237,740 1 (0.02%) 44,600 (0.02%) 65,02 4 273,183,037 1 (0.002%) 44,600 (0.02%)

1 

### National estimates for the small systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the large and very large systems are based directly on the UCMR 2 results, since this was a ce nsus, i.e., all large and very large systems were required to conduct UCMR 2 Assessment Monitoring. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 29 

# Terbufos sulfone was evaluated relative to an HRL of 0.35 μg/L. Exhibit 5-5 and Exhibit 5-6 present the number of systems and the population they serve with detections greater than

one- half the HRL and the HRL, respectively. The single detection of terbufos sulfone was equal to 0.42 μg/L, which exceeds one- half the HRL and the HRL. These findings suggest that an estimated one PWS serving 44,600 people nationally has terbufos sulfone detections greater than

one- half the HRL and the HRL. (Note that the estimates of national exceedance of these health thresholds are identical to the estimated terbufos sulfone national occurrence presented in Exhibit 5-4 above, since the single detection of terbufos sulfone was greater than the HRL .)

Exhibit 5-5: Terbufos Sulfone National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.175 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.175 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 618 1,790,743 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 182 878,262 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 800 2,669,004 0 (0%) 0 (0%) 61,684 46,614,302 0 (0%) 0 (0%)

. . . . Large Systems (serving 10,001 - 100,000 people)

-- CENSUS

. . . .

Ground Water 1,374 34,828,693 1 (0.07%) 44,600 (0.13%) 1,37 4 34,828,693 1 (0.07%) 44,600 (0.13%)

Surface Water 1,568 49,758,358 0 (0%) 0 (0%) 1,568 49,758,358 0 (0%) 0 (0%)

All Large Systems 2,942 84,587,051 1 (0.03%) 44,600 (0.05%) 2,94 2 84,587,051 1 (0.03%) 44,600 (0.05%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 4,140 229,237,740 1 (0.02%) 44,600 (0.02%) 65,02 4 273,183,037 1 (0.002%) 44,600 (0.02%)

1 

### National estimates for the small systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the large and very large systems are based directly on the UCMR 2 results, since this was a ce nsus, i.e., all large and very large systems were required to conduct UCMR 2 Assessment Monitoring. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 30 

# Exhibit 5-6: Terbufos Sulfone National Occurrence Measures from UCMR 2 Assessment Monitoring Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.35 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL (0.35 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 618 1,790,743 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 182 878,262 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 800 2,669,004 0 (0%) 0 (0%) 61,684 46,614,302 0 (0%) 0 (0%)

. . . . Large Systems (serving 10,001 - 100,000 people)

-- CENSUS

. . . .

Ground Water 1,374 34,828,693 1 (0.07%) 44,600 (0.13%) 1,37 4 34,828,693 1 (0.07%) 44,600 (0.13%)

Surface Water 1,568 49,758,358 0 (0%) 0 (0%) 1,568 49,758,358 0 (0%) 0 (0%)

All Large Systems 2,942 84,587,051 1 (0.03%) 44,600 (0.05%) 2,94 2 84,587,051 1 (0.03%) 44,600 (0.05%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 4,140 229,237,740 1 (0.02%) 44,600 (0.02%) 65,02 4 273,183,037 1 (0.002%) 44,600 (0.02%)

1 

### National estimates for the small systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the large and very large systems are based directly on the UCMR 2 results, since this was a ce nsus, i.e., all large and very large systems were required to conduct UCMR 2 Assessment Monitoring. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# 5.2 Screening Survey Contaminants with Detections

T his section presents summaries of occurrence results for Screening Survey contaminants with at least one detection. In the final UCMR 2 data set , 10 of the 15 Screening Survey contaminants had at least one detection. See Exhibit 2-1 for the list of Screening Survey contaminants, and their applicable analytical methods and MRLs. The following 10 subsections present detailed occurrence findings on those contaminants. UCMR 2 monitoring found no analytical detections for five Screening Survey contaminants (acetochlor, acetochlor OA,

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 31 

# alachlor, alachlor OA, and NDPA); as such these con taminants are not discussed in more detail here. Summary occurrence findings for these contaminants are presented in Exhibit 5-1 , Exhibit 5-2, and Appendix A. Counts of the number of systems and samples, by state, are included for all 15 Screening Survey contaminants in Appendix B.

5.2.1 Acetochlor ESA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 11,157 samples of acetochlor ESA were collected from 1,198 PWSs . Of these, 2 (0.02%) samples had analytical detections of acetochlor ESA at or above the MRL of 1 μg/L. The maximum detected concentration of acetochlor ESA was 1.2 μg/L, and the median value was 1.15263 μg/L. Appendix C includes more detailed occurrence numbers for acetochlor ESA, such as summa ry statistics by source water type and system size and the number and percentage of samples with detections exceeding the HRL.
One acetochlor ESA detection occurred in a small surface water system in Ohio; the other acetochlor ESA detection occurred in a very large surface water system in California. These two systems served a cumulative population of 3,832,155 people or 2.44% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of acetochlor ESA was 0.17%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-7.
The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally representative so national extrapolations are not necessary.
Acetochlor ESA is estimated to occur nationally in 16 small systems serving an estimated 46,701 people. Acetochlor ESA also occurred in one very large system serving 3,828,700 people. These findings suggest that an estimated 17 PWSs serving approximately 3.9 million people nationally have acetochlor ESA detections.

Exhibit 5-7: Acetochlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System an d Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 1 (0.42%) 3,455 (0.52%) 3,866 8,928,745 16 (0.42%) 46,701 (0.52%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 32 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

All Small Systems 480 1,208,921 1 (0.21%) 3,455 (0.29%) 61,684 46,614,302 16 (0.03%) 46,701 (0.1%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 1 (0.3%) 3,828,700 (3.07%) 335 124,711,765 1 (0.3%) 3,828,700 (3.07%)

All Very Large Systems 398 141,981,684 1 (0.25%) 3,828,700 (2.7%) 398 141,981,684 1 (0.25%) 3,828,700 (2.7%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 2 (0.17%) 3,832,155 (2.44%) 64,954 272,002,430 17 (0.03%) 3,875,401 (1.42%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# A cetochlor ESA was evaluated relative to an HRL of 1 μg/L. Exhibit 5-8 and Exhibit 5-9present the number of systems and the population they serve with detections greater than onehalf the HRL (0.5 μg/L) and the HRL (1 μg/L), r espectively.
Nationally, acetochlor ESA is estimated to exceed one- half the HRL and the HRL in 16 small systems serving an estimated 46,701 people. Acetochlor ESA also exceeded one- half the HRL and the HRL in one very large system serving 3,828,700 people. The refor e, an estimated 17 PWSs serving approximately 3.9 million people nationally are expected to have acetochlor ESA detections greater than one- half the HRL and the HRL. (Note that since all of the acetochlor ESA detections are greater than the HRL of 1 μg/L, the estimates of national exceedance of onehalf the HRL and the HRL are identical to the estimated acetochlor ESA national occurrence presented in Exhibit 5-7 above.)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 33 

# Exhibit 5-8: Acetochlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.5 μg/L) in the

UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.5 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 1 (0.42%) 3,455 (0.52%) 3,866 8,928,745 16 (0.42%) 46,701 (0.52%)

All Small Systems 480 1,208,921 1 (0.21%) 3,455 (0.29%) 61,684 46,614,302 16 (0.03%) 46,701 (0.1%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 1 (0.3%) 3,828,700 (3.07%) 335 124,711,765 1 (0.3%) 3,828,700 (3.07%)

All Very Large Systems 398 141,981,684 1 (0.25%) 3,828,700 (2.7%) 398 141,981,684 1 (0.25%) 3,828,700 (2.7%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 2 (0.17%) 3,832,155 (2.44%) 64,954 272,002,430 17 (0.03%) 3,875,401 (1.42%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 34 

# Exhibit 5-9: Acetochlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL

(1 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL (1 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 1 (0.42%) 3,455 (0.52%) 3,866 8,928,745 16 (0.42%) 46,701 (0.52%)

All Small Systems 480 1,208,921 1 (0.21%) 3,455 (0.29%) 61,684 46,614,302 16 (0.03%) 46,701 (0.1%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 1 (0.3%) 3,828,700 (3.07%) 335 124,711,765 1 (0.3%) 3,828,700 (3.07%)

All Very Large Systems 398 141,981,684 1 (0.25%) 3,828,700 (2.7%) 398 141,981,684 1 (0.25%) 3,828,700 (2.7%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 2 (0.17%) 3,832,155 (2.44%) 64,954 272,002,430 17 (0.03%) 3,875,401 (1.42%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA ’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full descr iption of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 35 

# 5.2.2 Alachlor ESA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 11,156 samples of alachlor ESA were collected from 1,198 PWSs . Of these, 5 samples (0.04 %) had analytical detections of alachlor ESA at or above the MRL of 1 μg/L. The maximum detected concentration of alachlor ESA was 1.3 μg/L and the median value was 1.2 μg/L. Appendix C includes more detailed occurrence numbers for alachlor ESA, such as summary statistics by source water type and system size and the number and percentage of samples with detections exceeding the HRL.
All but one of the alachlor ESA detections occurred in surface water systems. Alachlor ESA was detected in three systems in three states (California, Iowa, and Indiana). The systems with detections of alachlor ESA served a cumulative population of 3,910,398 people or 2.49% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small
, large, and very large UCMR 2 Screening Survey systems with at least one detection of alachlor ESA was 0.25%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-10.
The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally representative so national extrapolations are not necessary.
Alachlor ESA is estimated to occur nationally in 16 small systems serving approximately 105,000 people. It is also estimated to occur nationally in 10 large systems serving approximately 437,000 people. Alachlor ESA also occurred in one very large system serving 3,828,700 people. These findings suggest that an estimated 27 PWSs serving almost 4.4 million people nationally have alachlor ESA detections.

Exhibit 5- 10 : Alachlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 1 (0.42%) 7,705 (1.17%) 3,866 8,928,745 16 (0.42%) 104,148 (1.17%)

All Small Systems 480 1,208,921 1 (0.21%) 7,705 (0.64%) 61,684 46,614,302 16 (0.03%) 104,148 (0.22%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 36 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 1 (0.66%) 73,993 (1.12%) 1,506 38,870,272 10 (0.66%) 436,824 (1.12%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 1 (0.31%) 73,993 (0.53%) 2,872 83,406,444 10 (0.35%) 436,824 (0.52%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 1 (0.3%) 3,828,700 (3.07%) 335 124,711,765 1 (0.3%) 3,828,700 (3.07%)

All Very Large Systems 398 141,981,684 1 (0.25%) 3,828,700 (2.7%) 398 141,981,684 1 (0.25%) 3,828,700 (2.7%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 3 (0.25%) 3,910,398 (2.49%) 64,954 272,002,430 27 (0.04%) 4,369,672 (1.61%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# A lachlor ESA was evaluated relative to an HRL of 0.4 μg/L. Exhibit 5-11 and Exhibit 5-12 present the number of systems and the population they serve with detections greater than

one- half the HRL (0.2 μg/L) and the HRL (0.4 μg/L) , respectively.
Nationally, alachlor ESA is estimated to exceed one- half the HRL and the HRL in 16 small systems serving an estimated 104,148 people and 10 large systems serving an estimated 436,824 people. Alachlor ESA also exceeded one- half the HRL and the HRL in one very large system serving 3,828,700 people. These findings suggest that an estimated 27 PWSs serving almost 4.4 million people nationally have alachlor ESA detections greater than one- half the HRL and the HRL. (Note that since all of the al achlor ESA detections are greater than the HRL of 0.4 μg/L, the estimates of national exceedance of one- half the HRL and the HRL are identical to the estimated alachlor ESA national occurrence presented in Exhibit 5-10 above.)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 37 

# Exhibit 5- 11 : Alachlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Numbe r (and Percent) of Detections > 1/2 HRL (0.2 μg/L) in the

UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.2 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 1 (0.42%) 7,705 (1.17%) 3,866 8,928,745 16 (0.42%) 104,148 (1.17%)

All Small Systems 480 1,208,921 1 (0.21%) 7,705 (0.64%) 61,684 46,614,302 16 (0.03%) 104,148 (0.22%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 1 (0.66%) 73,993 (1.12%) 1,506 38,870,272 10 (0.66%) 436,824 (1.12%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 1 (0.31%) 73,993 (0.53%) 2,872 83,406,444 10 (0.35%) 436,824 (0.52%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 1 (0.3%) 3,828,700 (3.07%) 335 124,711,765 1 (0.3%) 3,828,700 (3.07%)

All Very Large Systems 398 141,981,684 1 (0.25%) 3,828,700 (2.7%) 398 141,981,684 1 (0.25%) 3,828,700 (2.7%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 3 (0.25%) 3,910,398 (2.49%) 64,954 272,002,430 27 (0.04%) 4,369,672 (1.61%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 38 

# Exhibit 5- 12 : Alachlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.4 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL (0.4 μg/L)

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 1 (0.42%) 7,705 (1.17%) 3,866 8,928,745 16 (0.42%) 104,148 (1.17%)

All Small Systems 480 1,208,921 1 (0.21%) 7,705 (0.64%) 61,684 46,614,302 16 (0.03%) 104,148 (0.22%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 1 (0.66%) 73,993 (1.12%) 1,506 38,870,272 10 (0.66%) 436,824 (1.12%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 1 (0.31%) 73,993 (0.53%) 2,872 83,406,444 10 (0.35%) 436,824 (0.52%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 1 (0.3%) 3,828,700 (3.07%) 335 124,711,765 1 (0.3%) 3,828,700 (3.07%)

All Very Large Systems 398 141,981,684 1 (0.25%) 3,828,700 (2.7%) 398 141,981,684 1 (0.25%) 3,828,700 (2.7%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 3 (0.25%) 3,910,398 (2.49%) 64,954 272,002,430 27 (0.04%) 4,369,672 (1.61%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# 5.2.3 Metolachlor
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 11,192 samples of metola chlor were collected from 1,198 PWSs . Of these, 3 samples (0.03%) had analytical detections of metolachlor at or above the MRL of 1 μg/L. The maximum detected concentration of metolachlor was 2.73235 μg/L and the median value was 1.4 μg/L. Appendix C includes more detailed occurrence numbers for metolachlor, such as summary statistics by source water type and system size.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 39 

# A ll three metolachlor detecti ons occurred in surface water systems, of which two detections were small systems and one was a very large system, in three states (Delaware, Indiana, and Oklahoma). These systems served a cumulative population of 107,510 people or 0.07% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of metolachlor was 0.25%. A summary of the number of systems with detections and the population

ser ved by them are presented in Exhibit 5-13.
The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3 .3). Occurrence results from the very large systems are already nationally representative so national extrapolations are not necessary.
Metolachlor is estimated to occur nationally in 32 small systems serving approximately 30,000 people. Metolachlor also occurred in one very large system serving 105,270 people. These findings suggest that an estimated 33 PWSs serving approximately 136,000 people nationally have metolachlor detections.

Exhibit 5- 13 : Metolachlor National Occurrence Measures from UCMR 2 Screening

Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . Natio nal Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 2 (0.83%) 2,240 (0.34%) 3,866 8,928,745 32 (0.83%) 30,278 (0.34%)

All Small Systems 480 1,208,921 2 (0.42%) 2,240 (0.19%) 61,684 46,614,302 32 (0.05%) 30,278 (0.06%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 40 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . Natio nal Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

Surface Water 335 124,711,765 1 (0.3%) 105,270 (0.08%) 335 124,711,765 1 (0.3%) 105,270 (0.08%)

All Very Large Systems 398 141,981,684 1 (0.25%) 105,270 (0.07%) 398 141,981,684 1 (0.25%) 105,270 (0.07%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 3 (0.25%) 107,510 (0.07%) 64,954 272,002,430 33 (0.05%) 135,548 (0.05%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# M etolachlor was evaluated relative to an HRL of 700 μg/L. None of the metolachlor detections exceeded one- half the HRL (350 μg/L) or the HRL (700 μg/L); thus no occurrence tables relative to the HRL are included below.

5.2.4 Metolachlor ESA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 11,157 samples of metolachlor ESA were collected from 1,198 PWSs . Of these, 52 samples (0.47%) had analytical detections of metolachlor ESA at or above the MRL of 1 μg/L. The maximum detected concentration of metolachlor ESA was 3.95455 μg/L and the median value was 1.44131 μg/L. Appendix C includes more detailed occurrence numbers for metolachlor ESA, such as summary statistics by source water type and system size.
Detections of metolachlor ESA occurred in 7 ground water and 12 surface water systems in 10 states. These 19 systems served a cumulative population of approximately 5.9 million people or 3.74% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of metolachlor ESA was 1.59%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-14.
The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally repres entative so national extrapolations are not necessary.
Metolachlor ESA is estimated to occur nationally in 1,253 small systems serving an estimated population of approximately 1.4 million people. It is also estimated to occur nationally in 34 large systems serving an estimated cumulative population of approximately 1.3 million

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 41 

# people. Metolachlor ESA also occurred in 7 very large systems serving 5.6 million people. These findings suggest that an estimated 1,294 PWSs serving more than 8.3 million people nationally have metolachlor ESA detections.

Exhibit 5- 14 : Metolachlor ESA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 5 (2.08%) 17,540 (3.2%) 57,818 37,685,557 1,205 (2.08%) 1,205,412 (3.2%)

Surface Water 240 660,557 3 (1.25%) 17,498 (2.65%) 3,866 8,928,745 48 (1.25%) 236,514 (2.65%)

All Small Systems 480 1,208,921 8 (1.67%) 35,038 (2.9%) 61,684 46,614,302 1,253 (2.03%) 1,441,926 (3.09%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 1 (0.66%) 73,993 (1.12%) 1,506 38,870,272 10 (0.66%) 436,824 (1.12%)

Surface Water 169 7,444,830 3 (1.78%) 138,897 (1.87%) 1,366 44,536,172 24 (1.78%) 830,904 (1.87%)

All Large Systems 320 14,029,015 4 (1.25%) 212,890 (1.52%) 2,872 83,406,444 34 (1.19%) 1,267,728 (1.52%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 1 (1.59%) 1,045,522 (6.05%) 63 17,269,919 1 (1.59%) 1,045,522 (6.05%)

Surface Water 335 124,711,765 6 (1.79%) 4,580,535 (3.67%) 335 124,711,765 6 (1.79%) 4,580,535 (3.67%)

All Very Large Systems 398 141,981,684 7 (1.76%) 5,626,057 (3.96%) 398 141,981,684 7 (1.76%) 5,626,057 (3.96%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 19 (1.59%) 5,873,985 (3.74%) 64,954 272,002,430 1,294 (1.99%) 8,335,711 (3.06%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 42 

# Metolachlor ESA was evaluated relative to an HRL of 700 μg/L. None of the metolachlor ESA detections exceeded one-half the HRL (350 μg/L) or the full HRL (700 μg/L); thus no occurrence tables relative to the HRL are included below.

5.2.5 Metolachlor OA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 11,157 samples of metolachlor OA were collected from 1,198 PWSs . Of these, 3 samples (0.03%) had analytical detections of metolachlor OA at or above the MRL of 2 μg/L. The maximum detected concentration of metolachlor OA was 3.539 μg/L and the median value was 3.078 μg/L. Appendix C includes more detailed occurrence numbers for metolachlor OA, such as summary statistics by source water type and system size.
All three metolachlor OA detections occurred in a single very large ground water system in the State of New York. This system served a population of approximately 1.05 million people or 0.67% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of metolachlor OA was 0.08%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-15.
The design of the UCMR 2 Screening S urvey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally representative so national extrapolations a re not necessary. These findings suggest that an estimated one PWS serving 1.05 million people nationally has metolachlor OA detections.

Exhibit 5- 15 : Metolachlor OA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 480 1,208,921 0 (0%) 0 (0%) 61,684 46,614,302 0 (0%) 0 (0%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 43 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 1 (1.59%) 1,045,522 (6.05%) 63 17,269,919 1 (1.59%) 1,045,522 (6.05%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 1 (0.25%) 1,045,522 (0.74%) 398 141,981,684 1 (0.25%) 1,045,522 (0.74%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 1 (0.08%) 1,045,522 (0.67%) 64,954 272,002,430 1 (0%) 1,045,522 (0.38%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# M etolachlor OA was evaluated relative to an HRL of 700 μg/L. None of the metolachlor OA detections exceeded one- half the HRL (350 μg/L) or the HRL (700 μg/L); thus no occurrence tables relative to the HRL are included below.

5.2.6 NDBA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 18,101 samples of NDBA were collected from 1,198 PWSs. Of these, 9 samples (0.05%) had analytical detections of NDBA at or above the MRL of 0.004 μg/L. The maximum detected concentration of NDBA was 0.02 062 μg/L and the median value was 0.00666 μg/L. Appendix C includes more detailed occurrence numbers for NDBA, such as summary statistics by source water type and system size.

Detections of NDBA occurred in three ground water and two surface water systems in four states. These five systems served a cumulati ve population of approximately 1.7 million people or 1.07% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of NDBA was 0.42%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-16.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 44 

# The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of o ccurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally representative so national extrapolations are not necessary.
NDBA is estimated to occur nationally in 482 small systems serving approximately 982,000 people. NDBA also occurred in 3 very large systems serving 1.67 million people. These findings suggest that an estimated 485 PWSs serving approximately 2.7 million people nationally have NDBA detections

.
Exhibit 5- 16 : NDBA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 2 (0.83%) 14,292 (2.61%) 57,818 37,685,557 482 (0.83%) 982,198 (2.61%)

Surface Water 240 660,557 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 480 1,208,921 2 (0.42%) 14,292 (1.18%) 61,684 46,614,302 482 (0.78%) 982,198 (2.11%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 1 (1.59%) 1,045,522 (6.05%) 63 17,269,919 1 (1.59%) 1,045,522 (6.05%)

Surface Water 335 124,711,765 2 (0.6%) 626,169 (0.5%) 335 124,711,765 2 (0.6%) 626,169 (0.5%)

All Very Large Systems 398 141,981,684 3 (0.75%) 1,671,691 (1.18%) 398 141,981,684 3 (0.75%) 1,671,691 (1.18%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 5 (0.42%) 1,685,983 (1.07%) 64,954 272,002,430 485 (0.75%) 2,653,889 (0.98%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 45 

# NDBA was evaluated relative to an HRL of 0. 03 μg/L. NDBA was evaluated relative to an HRL of 0.03 μg/L. Exhibit 5-17 and Exhibit 5-18 present the number of systems and the population they serve with detections greater t han one -half the HRL and the HRL, respectively. Nationally, ND B A is estimated to exceed one

- half the HRL in 241 small systems serving approximately 467,000 people. There were no exceedance s of the HRL.

Exhibit 5- 17 : NDBA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.015 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.015 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 1 (0.42%) 6,792 (1.24%) 57,818 37,685,557 241 (0.42%) 466,771 (1.24%)

Surface Water 240 660,557 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 480 1,208,921 1 (0.21%) 6,792 (0.56%) 61,684 46,614,302 241 (0.39%) 466,771 (1%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)
All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 1 (0.08%) 6,792 (0.004%) 64,954 272,002,430 241 (0.37%) 466,771 (0.17%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 46 

# Exhibit 5- 18 : NDBA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.03 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL (0.03 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 480 1,208,921 0 (0%) 0 (0%) 61,684 46,614,302 0 (0%) 0 (0%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 0 (0%) 0 (0%) 64,954 272,002,430 0 (0%) 0 (0%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA ’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full descr iption of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# 5.2.7 NDEA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 18,096 samples of NDEA were collected from 1,198 PWSs . Of these, 46 (0.25 %) samples had analytical detections of NDEA at or above the MRL of 0.005 μg/L. The maximum detected concentration of NDEA was 0.1 μg/L and the median value was 0.007 μg/L. Appendix C includes more detailed occurrence numbers for NDEA, such as summary statistics by source water type and system size and the number and percentage of samples with detections exceeding the HRL.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 47 

# N DEA was detected in seven ground and 19 surface water systems in eight states and one territory (Guam). The majority of these detectio ns occurred in very large surface water systems. Systems with detections served a cumulative population of approximately 11.2 million people or 7.14% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and ve ry large UCMR 2 Screening Survey systems with at least one detection of NDEA was 2.17%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-19.
The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally representative so na tional extrapolations are not necessary.
NDEA is estimated to occur nationally in 241 small systems serving approximately 452,000 people. It is also estimated to occur nationally in 34 large systems serving an estimated population of approximately 1.4 million people. NDEA also occurred in 21 very large systems serving approximately 11.0 million people. These findings suggest that an estimated 296 PWSs serving approximately 12.9 million people nationally have NDEA detections.

Exhibit 5- 19 : NDEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 1 (0.42%) 6,575 (1.2%) 57,818 37,685,557 241 (0.42%) 451,858 (1.2%)

Surface Water 240 660,557 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 480 1,208,921 1 (0.21%) 6,575 (0.54%) 61,684 46,614,302 241 (0.39%) 451,858 (0.97%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 1 (0.66%) 93,660 (1.42%) 1,506 38,870,272 10 (0.66%) 552,930 (1.42%)

Surface Water 169 7,444,830 3 (1.78%) 148,608 (2%) 1,366 44,536,172 24 (1.78%) 888,995 (2%)

All Large Systems 320 14,029,015 4 (1.25%) 242,268 (1.73%) 2,872 83,406,444 34 (1.19%) 1,441,924 (1.73%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 5 (7.94%) 668,861 (3.87%) 63 17,269,919 5 (7.94%) 668,861 (3.87%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 48 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

Surface Water 335 124,711,765 16 (4.78%) 10,314,490 (8.27%) 335 124,711,765 16 (4.78%) 10,314,490 (8.27%)

All Very Large Systems 398 141,981,684 21 (5.28%) 10,983,351 (7.74%) 398 141,981,684 21 (5.28%) 10,983,351 (7.74%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 26 (2.17%) 11,232,194 (7.14%) 64,954 272,002,430 296 (0.46%) 12,877,133 (4.73%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on th e UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# N DEA was evaluated relative to an HRL of 0.0004 μg/L. Exhibit 5-20 and Exhibit 5-21present the number of systems and the population they serve with detections greater than onehalf the HRL and the HRL, respectively. Nationally, NDEA is estimated to exceed one- half the HRL and the HRL in 241 small systems serving approximately 452,000 people and 34 large systems serving an estimated 1.4 million people. NDEA also exceeded one- half the HRL and the HRL in 21 very large systems serving approximately 11.0 million people. These findings suggest that an estimated 296 PWSs serving approximately 12.9 million people nationally have NDEA detections. (Note that since all of the NDEA detection s are greater than the HRL of 0.0004 μg/L, the estimates of national exceedance of one- half the HRL and the HRL are identical to the estimated NDEA national occurrence presented in Exhibit 5-19 above.)

Exhibit 5- 20 : NDEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.0002 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.0002 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 1 (0.42%) 6,575 (1.2%) 57,818 37,685,557 241 (0.42%) 451,858 (1.2%)

Surface Water 240 660,557 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 480 1,208,921 1 (0.21%) 6,575 (0.54%) 61,684 46,614,302 241 (0.39%) 451,858 (0.97%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 49 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.0002 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.0002 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 1 (0.66%) 93,660 (1.42%) 1,506 38,870,272 10 (0.66%) 552,930 (1.42%)

Surface Water 169 7,444,830 3 (1.78%) 148,608 (2%) 1,366 44,536,172 24 (1.78%) 888,995 (2%)

All Large Systems 320 14,029,015 4 (1.25%) 242,268 (1.73%) 2,872 83,406,444 34 (1.19%) 1,441,924 (1.73%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 5 (7.94%) 668,861 (3.87%) 63 17,269,919 5 (7.94%) 668,861 (3.87%)

Surface Water 335 124,711,765 16 (4.78%) 10,314,490 (8.27%) 335 124,711,765 16 (4.78%) 10,314,490 (8.27%)

All Very Large Systems 398 141,981,684 21 (5.28%) 10,983,351 (7.74%) 398 141,981,684 21 (5.28%) 10,983,351 (7.74%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 26 (2.17%) 11,232,194 (7.14%) 64,954 272,002,430 296 (0.46%) 12,877,133 (4.73%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA ’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full descr iption of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# E xhibit 5- 21 : NDEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.0004 μg/L) in the

UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL

(0.0004 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 1 (0.42%) 6,575 (1.2%) 57,818 37,685,557 241 (0.42%) 451,858 (1.2%)

Surface Water 240 660,557 0 (0%) 0 (0%) 3,866 8,928,745 0 (0%) 0 (0%)

All Small Systems 480 1,208,921 1 (0.21%) 6,575 (0.54%) 61,684 46,614,302 241 (0.39%) 451,858 (0.97%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 50 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.0004 μg/L) in the

UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL

(0.0004 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 1 (0.66%) 93,660 (1.42%) 1,506 38,870,272 10 (0.66%) 552,930 (1.42%)

Surface Water 169 7,444,830 3 (1.78%) 148,608 (2%) 1,366 44,536,172 24 (1.78%) 888,995 (2%)

All Large Systems 320 14,029,015 4 (1.25%) 242,268 (1.73%) 2,872 83,406,444 34 (1.19%) 1,441,924 (1.73%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 5 (7.94%) 668,861 (3.87%) 63 17,269,919 5 (7.94%) 668,861 (3.87%)

Surface Water 335 124,711,765 16 (4.78%) 10,314,490 (8.27%) 335 124,711,765 16 (4.78%) 10,314,490 (8.27%)

All Very Large Systems 398 141,981,684 21 (5.28%) 10,983,351 (7.74%) 398 141,981,684 21 (5.28%) 10,983,351 (7.74%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 26 (2.17%) 11,232,194 (7.14%) 64,954 272,002,430 296 (0.46%) 12,877,133 (4.73%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# 5.2.8 NDMA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 18,098 samples of NDMA were collected from 1,198 PWSs. Of these, 1,861 samples (10.3 %) had analytical detections of NDMA at or above the MRL of 0.002 μg/L. The maximum detected concentra tion of NDMA was 0.63 μg/L and the median value was 0.004 μg/L. Appendix C includes more detailed occurrence numbers for NDMA, such as summary statistics by source water type and system size and the number and percentage of samples with detections exceedin g the HRL.

NDMA was detected in 45 states and two territories (Guam and Puerto Rico). The majority of those detections occurred in surface water systems. The 324 systems with detections served a cumulative population of approximately 65.3 million people or 41.54% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of NDMA was 27.05%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-22.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 51 

# T he design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water sys tems (see Section 4.3.3). Occurrence results from the very large systems are already nationally representative so national extrapolations are not necessary.
NDMA is estimated to occur nationally in 3,601 small water systems serving an estimated 5.3 millio n people. It is also estimated to occur nationally in 598 large water systems of serving an estimated 21.1 million people. NDMA also occurred in 169 very large systems serving almost 61.5 million people. These findings suggest that an estimated 4,369 PWSs serving approximately 87.9 million people nationally have NDMA detections.

Exhibit 5- 22 : NDMA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 10 (4.17%) 26,059 (4.75%) 57,818 37,685,557 2,409 (4.17%) 1,790,869 (4.75%)

Surface Water 240 660,557 74 (30.83%) 259,285 (39.25%) 3,866 8,928,745 1,192 (30.83%) 3,504,746 (39.25%)

All Small Systems 480 1,208,921 84 (17.5%) 285,344 (23.6%) 61,684 46,614,302 3,601 (5.84%) 5,295,615 (11.36%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 13 (8.61%) 739,206 (11.23%) 1,506 38,870,272 130 (8.61%) 4,363,960 (11.23%)

Surface Water 169 7,444,830 58 (34.32%) 2,792,925 (37.51%) 1,366 44,536,172 469 (34.32%) 16,707,724 (37.51%)

All Large Systems 320 14,029,015 71 (22.19%) 3,532,130 (25.18%) 2,872 83,406,444 598 (20.84%) 21,071,684 (25.26%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 15 (23.81%) 5,706,228 (33.04%) 63 17,269,919 15 (23.81%) 5,706,228 (33.04%)

Surface Water 335 124,711,765 154 (45.97%) 55,788,062 (44.73%) 335 124,711,765 154 (45.97%) 55,788,062 (44.73%)

All Very Large Systems 398 141,981,684 169 (42.46%) 61,494,290 (43.31%) 398 141,981,684 169 (42.46%) 61,494,290 (43.31%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 52 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 324 (27.05%) 65,311,764 (41.54%) 64,954 272,002,430 4,369 (6.73%) 87,861,589 (32.3%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# NDM A was evaluated relative to an HRL of 0.0006 μg/L. Exhibit 5-23 and Exhibit 5-24present the number of systems and the population they serve with detections greater than onehalf the HRL and the HRL, respectively. Nati onally, NDMA is estimated to exceed one- half the HRL and the HRL in 3,601 small systems serving an estimated 5.3 million people and 598 large systems serving an estimated 21.1 million people. NDMA also exceeded one- half the HRL and the HRL in 169 very large systems serving approximately 61.5 million people. These findings suggest that an estimated 4,369 PWSs serving approximately 87.9 million people nationally have NDMA detections. (Note that since all of the NDMA detections are greater than the HRL of 0.0006 μg/L, the estimates of national exceedance of one- half the HRL and the HRL are identical to the estimated NDMA national occurrence presented in Exhibit 5-22 above.)

Exhibit 5- 23 : NDMA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.000 3 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.0003 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 10 (4.17%) 26,059 (4.75%) 57,818 37,685,557 2,409 (4.17%) 1,790,869 (4.75%)

Surface Water 240 660,557 74 (30.83%) 259,285 (39.25%) 3,866 8,928,745 1,192 (30.83%) 3,504,746 (39.25%)

All Small Systems 480 1,208,921 84 (17.5%) 285,344 (23.6%) 61,684 46,614,302 3,601 (5.84%) 5,295,615 (11.36%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 13 (8.61%) 739,206 (11.23%) 1,506 38,870,272 130 (8.61%) 4,363,960 (11.23%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 53 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.000 3 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.0003 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

Surface Water 169 7,444,830 58 (34.32%) 2,792,925 (37.51%) 1,366 44,536,172 469 (34.32%) 16,707,724 (37.51%)

All Large Systems 320 14,029,015 71 (22.19%) 3,532,130 (25.18%) 2,872 83,406,444 598 (20.84%) 21,071,684 (25.26%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 15 (23.81%) 5,706,228 (33.04%) 63 17,269,919 15 (23.81%) 5,706,228 (33.04%)

Surface Water 335 124,711,765 154 (45.97%) 55,788,062 (44.73%) 335 124,711,765 154 (45.97%) 55,788,062 (44.73%)

All Very Large Systems 398 141,981,684 169 (42.46%) 61,494,290 (43.31%) 398 141,981,684 169 (42.46%) 61,494,290 (43.31%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 324 (27.05%) 65,311,764 (41.54%) 64,954 272,002,430 4,369 (6.73%) 87,861,589 (32.3%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA ’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full descr iption of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# E xhibit 5- 24 : NDMA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.0006 μg/L) in the

UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detection s > HRL

(0.0006 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 10 (4.17%) 26,059 (4.75%) 57,818 37,685,557 2,409 (4.17%) 1,790,869 (4.75%)

Surface Water 240 660,557 74 (30.83%) 259,285 (39.25%) 3,866 8,928,745 1,192 (30.83%) 3,504,746 (39.25%)

All Small Systems 480 1,208,921 84 (17.5%) 285,344 (23.6%) 61,684 46,614,302 3,601 (5.84%) 5,295,615 (11.36%)

. . . . Large Systems (serving .10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 13 (8.61%) 739,206 (11.23%) 1,506 38,870,272 130 (8.61%) 4,363,960 (11.23%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 54 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.0006 μg/L) in the

UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detection s > HRL

(0.0006 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

Surface Water 169 7,444,830 58 (34.32%) 2,792,925 (37.51%) 1,366 44,536,172 469 (34.32%) 16,707,724 (37.51%)

All Large Systems 320 14,029,015 71 (22.19%) 3,532,130 (25.18%) 2,872 83,406,444 598 (20.84%) 21,071,684 (25.26%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 15 (23.81%) 5,706,228 (33.04%) 63 17,269,919 15 (23.81%) 5,706,228 (33.04%)

Surface Water 335 124,711,765 154 (45.97%) 55,788,062 (44.73%) 335 124,711,765 154 (45.97%) 55,788,062 (44.73%)

All Very Large Systems 398 141,981,684 169 (42.46%) 61,494,290 (43.31%) 398 141,981,684 169 (42.46%) 61,494,290 (43.31%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 324 (27.05%) 65,311,764 (41.54%) 64,954 272,002,430 4,369 (6.73%) 87,861,589 (32.3%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# 5.2.9 NMEA
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 18,101 samples of NMEA were collected from 1,198 PWSs . Of these, 3 samples (0.02%) had analytical detections of NMEA at or above the MRL of 0.003 μg/L. The maximum detected concentration of NMEA was 0.0049 μg/L and the median value was also 0.0045 μg/L. Appendix C includes more detailed occurrence numbers for NMEA, such as summary statistics by source water type and system size and the number and percentage of samples with detections exceeding the HRL.

All three NMEA detect ions occurred in three small surface water systems in two states (Oklahoma and Washington). These systems served a cumulative population of 4,480 people or 0.003% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of NMEA was 0.25%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-25.
The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally represe ntative so national extrapolations are not necessary.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 55 

# N MEA is estimated to occur nationally in 48 small water systems serving approximately 61,000 people. It is not estimated to occur nationally in any large or very large water systems. These findings sug gest that an estimated 48 PWSs serving approximately 6 1,000 people nationally have NMEA detections.

Exhibit 5- 25 : NMEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 3 (1.25%) 4,480 (0.68%) 3,866 8,928,745 48 (1.25%) 60,556 (0.68%)

All Small Systems 480 1,208,921 3 (0.63%) 4,480 (0.37%) 61,684 46,614,302 48 (0.08%) 60,556 (0.13%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 3 (0.25%) 4,480 (0.003%) 64,954 272,002,430 48 (0.07%) 60,556 (0.02%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# N MEA was evaluated relative to an HRL of 0.003 μg/L. Exhibit 5-26 and Exhibit 5-27 present the number of systems and the population they serve with detections greater than one-

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 56 

# half the HRL and the HRL, respectively. Nationally, NM EA is estimated to exceed one- half the HRL and the HRL in 48 small systems serving an estimated 61,000 people. NMEA is not estimated to occur nationally in any large or very large water systems. These findi ngs suggest that an estimated 48 PWSs serving approximately 61,000 people nationally have NMEA detections. (Note that since all of the NMEA detections are greater than the HRL of 0.003 μg/L, the estimates of national exceedance of one- half the HRL and the HRL are identical to the estimated NMEA national occurrence presented in Exhibit 5-25 above.)

Exhibit 5- 26 : NMEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data – Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.0015 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Nu mber (and Percent) of Detections > 1/2 HRL (0.0015 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 3 (1.25%) 4,480 (0.68%) 3,866 8,928,745 48 (1.25%) 60,556 (0.68%)

All Small Systems 480 1,208,921 3 (0.63%) 4,480 (0.37%) 61,684 46,614,302 48 (0.08%) 60,556 (0.13%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 3 (0.25%) 4,480 (0.003%) 64,954 272,002,430 48 (0.07%) 60,556 (0.02%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 57 

# E xhibit 5- 27 : NMEA National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.003 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL (0.003 μg/L) .

. Systems Population Systems Population Systems Population System s Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 3 (1.25%) 4,480 (0.68%) 3,866 8,928,745 48 (1.25%) 60,556 (0.68%)

All Small Systems 480 1,208,921 3 (0.63%) 4,480 (0.37%) 61,684 46,614,302 48 (0.08%) 60,556 (0.13%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 0 (0%) 0 (0%) 1,366 44,536,172 0 (0%) 0 (0%)

All Large Systems 320 14,029,015 0 (0%) 0 (0%) 2,872 83,406,444 0 (0%) 0 (0%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 0 (0%) 0 (0%) 63 17,269,919 0 (0%) 0 (0%)

Surface Water 335 124,711,765 0 (0%) 0 (0%) 335 124,711,765 0 (0%) 0 (0%)

All Very Large Systems 398 141,981,684 0 (0%) 0 (0%) 398 141,981,684 0 (0%) 0 (0%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 3 (0.25%) 4,480 (0.003%) 64,954 272,002,430 48 (0.07%) 60,556 (0.02%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 58 

# 5.2.10 NPYR
As indicated in Appendices A and B, u nder the UCMR 2 Screening Survey 18,101 samples of NPYR were collected from 1,198 PWSs . Of these, 41 samples (0.23%) had analytical detections of NPYR at or above the MRL of 0.002 μg/L. The maximum detected concentration of NPYR was 0.0238 μg/L and the median value was 0.0039 μg/L. Appendix C includes more detailed occurrence numbers for NPYR, such as summary statistics by source water type and system size and the number and percentage of samples with detections exceeding the HRL.
The 41 NPYR detections occurred in 21 systems in 10 states ; all but one of the systems

were surface water systems. The 21 systems served a cumulative population of approximately 7.4 million people, or 4.73% of the total population served by UCMR 2 Screening Survey PWSs. The percentage of all small, large, and very large UCMR 2 Screening Survey systems with at least one detection of NPYR was 1.75%. A summary of the number of systems with detections and the population served by them are presented in Exhibit 5-28.
The design of the UCMR 2 Screening Survey enables extrapolation of national estimates of occurrence of contaminants detected in small and large water systems (see Section 4.3.3). Occurrence results from the very large systems are already nationally representative so national extrapolations are not necessary.
NPYR is estimated to occur nationally in 48 small systems serving approximately 197,000 people. It is also estimated to occur nationally in 48 large systems serving an estimated 1.1 million people. NPYR also occurred in 12 very large systems serving about 7.2 million people. These findings suggest that an estimated 109 PWSs serving approximately 8.6 million people nationally have NPYR detections.

Exhibit 5- 28 : NPYR National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - All Detections

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 3 (1.25%) 14,572 (2.21%) 3,866 8,928,745 48 (1.25%) 196,970 (2.21%)

All Small Systems 480 1,208,921 3 (0.63%) 14,572 (1.21%) 61,684 46,614,302 48 (0.08%) 196,970 (0.42%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 59 Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections .

. Systems Population Systems Population Systems Population Systems Population

Surface Water 169 7,444,830 6 (3.55%) 188,603 (2.53%) 1,366 44,536,172 48 (3.55%) 1,128,251 (2.53%)

All Large Systems 320 14,029,015 6 (1.88%) 188,603 (1.34%) 2,872 83,406,444 48 (1.69%) 1,128,251 (1.35%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 1 (1.59%) 148,137 (0.86%) 63 17,269,919 1 (1.59%) 148,137 (0.86%)

Surface Water 335 124,711,765 11 (3.28%) 7,080,239 (5.68%) 335 124,711,765 11 (3.28%) 7,080,239 (5.68%)

All Very Large Systems 398 141,981,684 12 (3.02%) 7,228,376 (5.09%) 398 141,981,684 12 (3.02%) 7,228,376 (5.09%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 21 (1.75%) 7,431,551 (4.73%) 64,954 272,002,430 109 (0.17%) 8,553,597 (3.14%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.



# N PYR was evaluated relative to an HRL of 0.002 μg/L. Exhibit 5-29 and Exhibit 5-30 present the number of systems with detections greater than one- half the HRL and the HRL, respecti vely as well as the population they serve. NPYR is estimated to occur greater than one

half the HRL and the HRL in 48 small systems serving approximately 197,000 people nationally. It is also estimated to occur nationally greater than one- half the HRL and the HRL in 48 large systems serving an estimated 1.1 million people. NPYR also occurred in 12 very large systems serving about 7.2 million people. These findings suggest that an estimated 109 PWSs serving approximately 8.6 million people nationally have NPYR detections greater than the HRL. (Note that since all of the NPYR detections are greater than the HRL of 0.002 μg/L, the estimates of national exceedance of one- half the HRL and the HRL are identical to the estimated NPYR national occurrence presented in Exhibit 6-27 above.)

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 60 

# Exhibit 5- 29 : NPYR National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > 1⁄2 HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > 1/2 HRL (0.001 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > 1/2 HRL (0.001 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 3 (1.25%) 14,572 (2.21%) 3,866 8,928,745 48 (1.25%) 196,970 (2.21%)

All Small Systems 480 1,208,921 3 (0.63%) 14,572 (1.21%) 61,684 46,614,302 48 (0.08%) 196,970 (0.42%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 6 (3.55%) 188,603 (2.53%) 1,366 44,536,172 48 (3.55%) 1,128,251 (2.53%)

All Large Systems 320 14,029,015 6 (1.88%) 188,603 (1.34%) 2,872 83,406,444 48 (1.69%) 1,128,251 (1.35%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 1 (1.59%) 148,137 (0.86%) 63 17,269,919 1 (1.59%) 148,137 (0.86%)

Surface Water 335 124,711,765 11 (3.28%) 7,080,239 (5.68%) 335 124,711,765 11 (3.28%) 7,080,239 (5.68%)

All Very Large Systems 398 141,981,684 12 (3.02%) 7,228,376 (5.09%) 398 141,981,684 12 (3.02%) 7,228,376 (5.09%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 21 (1.75%) 7,431,551 (4.73%) 64,954 272,002,430 109 (0.17%) 8,553,597 (3.14%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e. , all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full description of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 61 

# Exhibit 5- 30 : NPYR National Occurrence Measures from UCMR 2 Screening Survey Data - Summary of System and Population Served Data - Detections > HRL

Source Water Type UCMR 2 Sample

. Number (and Percent) of Detections > HRL (0.002 μg/L) in the UCMR 2 Sample . National Inventory

. National Estimate 1 

### of the Number (and Percent) of Detections > HRL (0.002 μg/L) .

. Systems Population Systems Population Systems Population Systems Population

. . . . Small Systems (serving ≤ 10,000 people)

. . . .

Ground Water 240 548,364 0 (0%) 0 (0%) 57,818 37,685,557 0 (0%) 0 (0%)

Surface Water 240 660,557 3 (1.25%) 14,572 (2.21%) 3,866 8,928,745 48 (1.25%) 196,970 (2.21%)

All Small Systems 480 1,208,921 3 (0.63%) 14,572 (1.21%) 61,684 46,614,302 48 (0.08%) 196,970 (0.42%)

. . . . Large Systems (serving 10,001 - 100,000 people)

. . . .

Ground Water 151 6,584,184 0 (0%) 0 (0%) 1,506 38,870,272 0 (0%) 0 (0%)

Surface Water 169 7,444,830 6 (3.55%) 188,603 (2.53%) 1,366 44,536,172 48 (3.55%) 1,128,251 (2.53%)

All Large Systems 320 14,029,015 6 (1.88%) 188,603 (1.34%) 2,872 83,406,444 48 (1.69%) 1,128,251 (1.35%)

. . . . Very Large Systems (serving > 100,000 people)

-- CENSUS

. . . .

Ground Water 63 17,269,919 1 (1.59%) 148,137 (0.86%) 63 17,269,919 1 (1.59%) 148,137 (0.86%)

Surface Water 335 124,711,765 11 (3.28%) 7,080,239 (5.68%) 335 124,711,765 11 (3.28%) 7,080,239 (5.68%)
All Very Large Systems 398 141,981,684 12 (3.02%) 7,228,376 (5.09%) 398 141,981,684 12 (3.02%) 7,228,376 (5.09%)

. . . . All Systems

. . . .
All Water Systems 1,198 157,219,620 21 (1.75%) 7,431,551 (4.73%) 64,954 272,002,430 109 (0.17%) 8,553,597 (3.14%)

1 

### National estimates for the small and large systems are extrapolations generated by multiplying the UCMR 2 national statistical sample findings of system/population percentages by the national system/population inventory numbers for PWSs developed from EPA ’s SDWIS, the CWSS, and UCMR. National estimates for the very large systems are based directly on the UCMR 2 results, since this was a census, i.e., all very large systems were required to conduct UCMR 2 Screening Survey. See Section 4.3.3 for a full descr iption of national extrapolations. Due to rounding, some calculations may appear to be incorrect

.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 62 

# 6 References

Uni ted States Environmental Protection Agency (USEPA). 1999. Revisions to the Unregulated Contaminant Monitoring Regulation for Public Water Systems. Federal Register . Vol. 64, no. 180, p. 50556, September 17, 1999.

USEPA. 2001 . Statistical Design and Sample Selection for the Unregulated Contaminant Monitoring Regulation (1999). August 2001. EPA-815-R-01-004, Office of Water.

USEPA. 2002. Analysis of National Occurrence of the 1998 Contaminant Candidate List (CCL) Regulatory Determination Priority Contaminants in Public Water Systems. May 2002. EPA-815- D-01- 002, Office of Water.

USEPA. 2003a. Occurrence Estimation Methodology and Occurrence Findings for Six- Year Review of National Primary Drinking Water Regulations . June 2003. EPA-815-R-03-006, Office of Water.

USEPA. 2003b. Quality Assurance Project Plan for the Implementation of the Unregulated Contaminant Monitoring Regulation. Draft. April 2003. Office of Water.
USEPA. 2005. Unregulated Contaminant Monitoring Regulation (UCMR) for Public Water System s Revisions; Proposed Rule. Federal Register . Vol. 70, no. 161, p. 49093, August 22, 2005.

USEPA. 2006. Reference Guide for the Second Cycle of the Unregulated Contaminant Monitoring Regulation ( UCMR 2) . December 2006. EPA-815-R-06- 016, Office of Water.
USEPA. 2007. Unregulated Contaminant Monitoring Regulation (UCMR) for Public Water Systems Revisions; Final Rule. Federal Register . Vol. 72, no. 2, p. 367, January 4, 2007.

USEPA. 2008a. The Analysis of Occurrence Data from the Unregulated Contaminant Mon itoring Program (UCM) and National Inorganics and Radionuclides Survey (NIRS) in Support of Regulatory Determinations for the Second Drinking Water Contaminant Candidate List (CCL 2). June 2008. EPA -815-R-08-014, Office of Water.

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 . June 2008. EPA-815-R-08- 013, Office of Water.

USEPA. 2009. Standard Operating Procedure: NCOD Data Import for Small Systems for the Second Cycle of the Unregulated Contaminant Monitoring Regulation. Revision 1.0. December 2009. SOP TSC UCMR2 004.

USEPA. 2010. Technical Description of the Statistical Model of Pe rchlorate Occurrence in Drinking Water. Peer Reviewed Draft Report.

## EPA

- OGWDW Occurrence Data from the UCMR 2



# 63 

# USEPA . 2014a. Protocol for the Regulatory Determination 3 . Post-expert review final. Including Appendices A- F. April 2014. EPA -815-R-14-005.
USEPA 2014b. Announcement of Preliminary Regulatory Determinations for Contaminants on the Third Drinking Water Contaminant Candidate List. Federal Register. Vol. 79, No. 202, pp. 62715-62750.

USEPA. 2015. Regulatory Determination 3 Support Document. EPA 815-R-15-014.

## EPA

- OGWDW Occurrence Da ta f rom the UC

MR 2



# List of Appendix Tables

Appendix A. Final UCMR 2 Data: Summary of Occurrence Based on Samples, Systems, and Population Served
Appendix B. Final UCMR 2 Data: Summary of Systems and Population Served by State
Appendix C. Final UCMR 2 Data: Summary of Sam ples (Relative to the HRL) and Summary of Detected Concentrations

## EPA

- OGWDW Occurrence Da ta f rom the UC

MR 2



# Appendix A

Table A1. BDE-47 – Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served
Table A2. BDE-99 - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served
Table A3. BDE-100 - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Sa mples, Systems, and Population Served
Table A4. BDE-153 - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served
Table A5. Dimethoate - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Sy stems, and Population Served Table A6. 1,3-Dinitrobenzene - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served
Table A7. HBB - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems , and Population Served
Table A8. RDX - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served
Table A9. Terbufos Sulfone - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served
Table A10. TNT - Final UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served
Table A11. Acetochlor - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A12. Acetochlor ESA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A13. Acetochlor OA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A14. Alachlor - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A15. Alachlor ESA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A16. Alachlor OA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A17. Metolachlor - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

## EPA

- OGWDW Occurrence Da ta f rom the UC

MR 2



# Table A18. Metolachlor ESA - Fin al UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A19. Metolachlor OA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A20. NDBA - Final UCMR 2 Screen ing Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A21. NDEA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A22. NDMA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A23. NDPA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served
Table A24. NMEA - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Syste ms, and Population Served
Table A25. NPYR - Final UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A1. BDE-47 - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 920 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,248 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 0 0.00% 1,374 0 0.00% 34,828,693 0 0.00%

Surface Water 10,331 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,091 0 0.00% 2,942 0 0.00% 84,587,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,796 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,810 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,149 0 0.00% 4,140 0 0.00% 229,237,740 0 0.00%



# Page 1 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A2. BDE-99 - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 920 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,248 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 0 0.00% 1,374 0 0.00% 34,828,693 0 0.00%

Surface Water 10,331 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,091 0 0.00% 2,942 0 0.00% 84,587,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,796 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,810 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,149 0 0.00% 4,140 0 0.00% 229,237,740 0 0.00%



# Page 2 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A3. BDE-100 - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 920 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,248 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 0 0.00% 1,374 0 0.00% 34,828,693 0 0.00%

Surface Water 10,331 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,091 0 0.00% 2,942 0 0.00% 84,587,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,796 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,810 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,149 0 0.00% 4,140 0 0.00% 229,237,740 0 0.00%



# Page 3 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A4. BDE-153 - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 920 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,248 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,759 0 0.00% 1,374 0 0.00% 34,828,693 0 0.00%

Surface Water 10,324 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,083 0 0.00% 2,942 0 0.00% 84,587,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,794 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,808 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,139 0 0.00% 4,140 0 0.00% 229,237,740 0 0.00%



# Page 4 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A5. Dimethoate - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 920 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,248 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 0 0.00% 1,374 0 0.00% 34,828,693 0 0.00%

Surface Water 10,332 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,092 0 0.00% 2,942 0 0.00% 84,587,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,796 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,810 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,150 0 0.00% 4,140 0 0.00% 229,237,740 0 0.00%



# Page 5 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A6. 1,3-Dinitrobenzene - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,332 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 919 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,251 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,761 0 0.00% 1,373 0 0.00% 34,816,693 0 0.00%

Surface Water 10,327 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,088 0 0.00% 2,941 0 0.00% 84,575,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,012 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,801 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,813 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,152 0 0.00% 4,139 0 0.00% 229,225,740 0 0.00%



# Page 6 of 25

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Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A7. HBB - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 920 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,248 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,759 0 0.00% 1,374 0 0.00% 34,828,693 0 0.00%

Surface Water 10,328 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,087 0 0.00% 2,942 0 0.00% 84,587,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,794 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,808 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,143 0 0.00% 4,140 0 0.00% 229,237,740 0 0.00%



# Page 7 of 25

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Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A8. RDX - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,332 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 919 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,251 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 0 0.00% 1,373 0 0.00% 34,816,693 0 0.00%

Surface Water 10,327 4 0.04% 1,568 3 0.19% 49,758,358 96,033 0.19%
All Large Systems 22,087 4 0.02% 2,941 3 0.10% 84,575,051 96,033 0.11%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,012 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,800 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,812 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,150 4 0.01% 4,139 3 0.07% 229,225,740 96,033 0.04%



# Page 8 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A9. Terbufos Sulfone - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 920 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,248 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 1 0.01% 1,374 1 0.07% 34,828,693 44,600 0.13%

Surface Water 10,331 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,091 1 0.005% 2,942 1 0.03% 84,587,051 44,600 0.05%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,796 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,810 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,149 1 0.003% 4,140 1 0.02% 229,237,740 44,600 0.02%



# Page 9 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A10. TNT - UCMR 2 Assessment Monitoring Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,332 0 0.00% 618 0 0.00% 1,790,743 0 0.00%

Surface Water 919 0 0.00% 182 0 0.00% 878,262 0 0.00%
All Small Systems 3,251 0 0.00% 800 0 0.00% 2,669,004 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 0 0.00% 1,373 0 0.00% 34,816,693 0 0.00%

Surface Water 10,327 0 0.00% 1,568 0 0.00% 49,758,358 0 0.00%
All Large Systems 22,087 0 0.00% 2,941 0 0.00% 84,575,051 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,012 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,801 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,813 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 32,151 0 0.00% 4,139 0 0.00% 229,225,740 0 0.00%



# Page 10 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A11. Acetochlor - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 788 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,040 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 1,828 0 0.00% 480 0 0.00% 1,208,921 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,392 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 1,178 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,570 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,010 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,785 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,795 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 11,193 0 0.00% 1,198 0 0.00% 157,219,620 0 0.00%



# Page 11 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A12. Acetochlor ESA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,035 1 0.10% 240 1 0.42% 660,557 3,455 0.52%
All Small Systems 1,821 1 0.05% 480 1 0.21% 1,208,921 3,455 0.29%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 1,170 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,551 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,786 1 0.02% 335 1 0.30% 124,711,765 3,828,700 3.07%
All Very Large Systems 6,785 1 0.01% 398 1 0.25% 141,981,684 3,828,700 2.70%
All Systems
All Water Systems 11,157 2 0.02% 1,198 2 0.17% 157,219,620 3,832,155 2.44%



# Page 12 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A13. Acetochlor OA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,035 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 1,821 0 0.00% 480 0 0.00% 1,208,921 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 1,170 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,551 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,786 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,785 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 11,157 0 0.00% 1,198 0 0.00% 157,219,620 0 0.00%



# Page 13 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A14. Alachlor - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 788 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,040 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 1,828 0 0.00% 480 0 0.00% 1,208,921 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,392 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 1,178 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,570 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,010 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,785 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,795 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 11,193 0 0.00% 1,198 0 0.00% 157,219,620 0 0.00%



# Page 14 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A15. Alachlor ESA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,035 3 0.29% 240 1 0.42% 660,557 7,705 1.17%
All Small Systems 1,821 3 0.16% 480 1 0.21% 1,208,921 7,705 0.64%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 1 0.07% 151 1 0.66% 6,584,184 73,993 1.12%

Surface Water 1,170 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,551 1 0.04% 320 1 0.31% 14,029,015 73,993 0.53%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,785 1 0.02% 335 1 0.30% 124,711,765 3,828,700 3.07%
All Very Large Systems 6,784 1 0.01% 398 1 0.25% 141,981,684 3,828,700 2.70%
All Systems
All Water Systems 11,156 5 0.04% 1,198 3 0.25% 157,219,620 3,910,398 2.49%



# Page 15 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A16. Alachlor OA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,035 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 1,821 0 0.00% 480 0 0.00% 1,208,921 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 1,170 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,551 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,786 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,785 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 11,157 0 0.00% 1,198 0 0.00% 157,219,620 0 0.00%



# Page 16 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A17. Metolachlor - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 788 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,040 2 0.19% 240 2 0.83% 660,557 2,240 0.34%
All Small Systems 1,828 2 0.11% 480 2 0.42% 1,208,921 2,240 0.19%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,392 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 1,178 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,570 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,010 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 4,784 1 0.02% 335 1 0.30% 124,711,765 105,270 0.08%
All Very Large Systems 6,794 1 0.01% 398 1 0.25% 141,981,684 105,270 0.07%
All Systems
All Water Systems 11,192 3 0.03% 1,198 3 0.25% 157,219,620 107,510 0.07%



# Page 17 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A18. Metolachlor ESA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 16 2.04% 240 5 2.08% 548,364 17,540 3.20%

Surface Water 1,035 5 0.48% 240 3 1.25% 660,557 17,498 2.65%
All Small Systems 1,821 21 1.15% 480 8 1.67% 1,208,921 35,038 2.90%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 4 0.29% 151 1 0.66% 6,584,184 73,993 1.12%

Surface Water 1,170 8 0.68% 169 3 1.78% 7,444,830 138,897 1.87%
All Large Systems 2,551 12 0.47% 320 4 1.25% 14,029,015 212,890 1.52%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 9 0.45% 63 1 1.59% 17,269,919 1,045,522 6.05%

Surface Water 4,786 10 0.21% 335 6 1.79% 124,711,765 4,580,535 3.67%
All Very Large Systems 6,785 19 0.28% 398 7 1.76% 141,981,684 5,626,057 3.96%
All Systems
All Water Systems 11,157 52 0.47% 1,198 19 1.59% 157,219,620 5,873,985 3.74%



# Page 18 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A19. Metolachlor OA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,035 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 1,821 0 0.00% 480 0 0.00% 1,208,921 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 1,170 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 2,551 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 3 0.15% 63 1 1.59% 17,269,919 1,045,522 6.05%

Surface Water 4,786 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 6,785 3 0.04% 398 1 0.25% 141,981,684 1,045,522 0.74%
All Systems
All Water Systems 11,157 3 0.03% 1,198 1 0.08% 157,219,620 1,045,522 0.67%



# Page 19 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A20. NDBA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 3 0.24% 240 2 0.83% 548,364 14,292 2.61%

Surface Water 1,996 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 3,233 3 0.09% 480 2 0.42% 1,208,921 14,292 1.18%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 2,091 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 4,023 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 3 0.10% 63 1 1.59% 17,269,919 1,045,522 6.05%

Surface Water 7,879 3 0.04% 335 2 0.60% 124,711,765 626,169 0.50%
All Very Large Systems 10,845 6 0.06% 398 3 0.75% 141,981,684 1,671,691 1.18%
All Systems
All Water Systems 18,101 9 0.05% 1,198 5 0.42% 157,219,620 1,685,983 1.07%



# Page 20 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A21. NDEA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 1 0.08% 240 1 0.42% 548,364 6,575 1.20%

Surface Water 1,996 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 3,233 1 0.03% 480 1 0.21% 1,208,921 6,575 0.54%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,920 3 0.16% 151 1 0.66% 6,584,184 93,660 1.42%

Surface Water 2,091 6 0.29% 169 3 1.78% 7,444,830 148,608 2.00%
All Large Systems 4,011 9 0.22% 320 4 1.25% 14,029,015 242,268 1.73%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,968 7 0.24% 63 5 7.94% 17,269,919 668,861 3.87%

Surface Water 7,884 29 0.37% 335 16 4.78% 124,711,765 10,314,490 8.27%
All Very Large Systems 10,852 36 0.33% 398 21 5.28% 141,981,684 10,983,351 7.74%
All Systems
All Water Systems 18,096 46 0.25% 1,198 26 2.17% 157,219,620 11,232,194 7.14%



# Page 21 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A22. NDMA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 14 1.13% 240 10 4.17% 548,364 26,059 4.75%

Surface Water 1,996 326 16.33% 240 74 30.83% 660,557 259,285 39.25%
All Small Systems 3,233 340 10.52% 480 84 17.50% 1,208,921 285,344 23.60%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 48 2.48% 151 13 8.61% 6,584,184 739,206 11.23%

Surface Water 2,091 305 14.59% 169 58 34.32% 7,444,830 2,792,925 37.51%
All Large Systems 4,023 353 8.77% 320 71 22.19% 14,029,015 3,532,130 25.18%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 52 1.75% 63 15 23.81% 17,269,919 5,706,228 33.04%

Surface Water 7,876 1,116 14.17% 335 154 45.97% 124,711,765 55,788,062 44.73%
All Very Large Systems 10,842 1,168 10.77% 398 169 42.46% 141,981,684 61,494,290 43.31%
All Systems
All Water Systems 18,098 1,861 10.28% 1,198 324 27.05% 157,219,620 65,311,764 41.54%



# Page 22 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A23. NDPA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,996 0 0.00% 240 0 0.00% 660,557 0 0.00%
All Small Systems 3,233 0 0.00% 480 0 0.00% 1,208,921 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 2,091 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 4,023 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,968 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 7,883 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 10,851 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 18,107 0 0.00% 1,198 0 0.00% 157,219,620 0 0.00%



# Page 23 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A24. NMEA - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,996 3 0.15% 240 3 1.25% 660,557 4,480 0.68%
All Small Systems 3,233 3 0.09% 480 3 0.63% 1,208,921 4,480 0.37%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 2,091 0 0.00% 169 0 0.00% 7,444,830 0 0.00%
All Large Systems 4,023 0 0.00% 320 0 0.00% 14,029,015 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 0 0.00% 63 0 0.00% 17,269,919 0 0.00%

Surface Water 7,879 0 0.00% 335 0 0.00% 124,711,765 0 0.00%
All Very Large Systems 10,845 0 0.00% 398 0 0.00% 141,981,684 0 0.00%
All Systems
All Water Systems 18,101 3 0.02% 1,198 3 0.25% 157,219,620 4,480 0.003%



# Page 24 of 25

# EPA-OGWDW

Appendix A. Summary of Occurrence Based on Samples, Systems, and Population Served Occurrence Data from the UCMR 2

Table A25. NPYR - UCMR 2 Screening Survey Data - Occurrence Based on Samples, Systems, and Population Served

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Total Number

of Systems Systems with

Detections: Number Systems with

Detections: Percent Population

Served by Systems Population

Served by Systems with Detections: Number Population

Served by Systems with Detections: Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 0 0.00% 240 0 0.00% 548,364 0 0.00%

Surface Water 1,996 11 0.55% 240 3 1.25% 660,557 14,572 2.21%
All Small Systems 3,233 11 0.34% 480 3 0.63% 1,208,921 14,572 1.21%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 0 0.00% 151 0 0.00% 6,584,184 0 0.00%

Surface Water 2,091 7 0.33% 169 6 3.55% 7,444,830 188,603 2.53%
All Large Systems 4,023 7 0.17% 320 6 1.88% 14,029,015 188,603 1.34%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 1 0.03% 63 1 1.59% 17,269,919 148,137 0.86%

Surface Water 7,879 22 0.28% 335 11 3.28% 124,711,765 7,080,239 5.68%
All Very Large Systems 10,845 23 0.21% 398 12 3.02% 141,981,684 7,228,376 5.09%
All Systems
All Water Systems 18,101 41 0.23% 1,198 21 1.75% 157,219,620 7,431,551 4.73%



# Page 25 of 25

## EPA

- OGWDW Occurrence Da ta f rom the UC

MR 2



# Appendix B

Tabl e B1. BDE-47 - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B2. BDE -99 - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B3. BDE -100 - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B4. BDE -153 - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B5. Dimethoate - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B6. 1,3-Dinitrobenzene - Final UCMR 2 As sessment Monitoring Data - Number of Systems and Population Served by State
Table B7. HBB - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B8. RDX - Final UCMR 2 Assessment Monitoring Data - Number of S ystems and Population Served by State
Table B9 . Terbufos Sulfone - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B10

. TNT - Final UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State
Table B11

. Acetochlor - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B12

. Acetochlor ESA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B13

. Acet ochlor OA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B14

. Alachlor - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B15

. Alachlor ESA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B16

. Alachlor OA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B17

. Metolachlor - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

## EPA

- OGWDW Occurrence Da ta f rom the UC

MR 2



# Table B18

. Metolachlor ESA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B19

. Metolachlor OA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B20

. NDBA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B21

. NDEA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B22

. NDMA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B23

. NDPA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B24

. NMEA - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State
Table B25

. NPYR - Final UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 49 9 3 2 2 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 951 69 13 0 41 5 1 9 Arkansas 289 61 9 4 17 28 0 3 California 6,725 393 32 14 123 152 8 64 Colorado 505 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,152 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 246 3 0 0 0 2 1 0 Hawaii 315 18 3 0 8 5 2 0 Idaho 257 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 233 54 14 1 24 12 0 3 Kansas 224 46 7 4 12 17 0 6 Kentucky 433 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 636 78 30 0 46 0 0 2 Missouri 464 75 16 4 31 19 1 4 Montana 112 13 4 2 1 5 0 1 N. Mariana Islands 69 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,055 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,542 154 18 11 47 59 5 14 North Carolina 1,032 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 422 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 655 83 6 5 17 47 0 8 Rhode Island 92 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,200 295 63 23 62 122 1 24 Utah 513 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 834 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 56 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,149 4,140 618 182 1,374 1,568 63 335
1 The UCMR data are not representative at the state-level. 

## Table B1. BDE-47 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

State 1 Total Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 234,237 6,025 9,791 59,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,237,740 1,790,743 878,262 34,828,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level. 

## Table B1. BDE-47 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B2. BDE-99 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 49 9 3 2 2 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 951 69 13 0 41 5 1 9 Arkansas 289 61 9 4 17 28 0 3 California 6,725 393 32 14 123 152 8 64 Colorado 505 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,152 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 246 3 0 0 0 2 1 0 Hawaii 315 18 3 0 8 5 2 0 Idaho 257 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 233 54 14 1 24 12 0 3 Kansas 224 46 7 4 12 17 0 6 Kentucky 433 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 636 78 30 0 46 0 0 2 Missouri 464 75 16 4 31 19 1 4 Montana 112 13 4 2 1 5 0 1 N. Mariana Islands 69 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,055 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,542 154 18 11 47 59 5 14 North Carolina 1,032 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 422 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 655 83 6 5 17 47 0 8 Rhode Island 92 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,200 295 63 23 62 122 1 24 Utah 513 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 834 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 56 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,149 4,140 618 182 1,374 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B2. BDE-99 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 234,237 6,025 9,791 59,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,237,740 1,790,743 878,262 34,828,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B3. BDE-100 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 49 9 3 2 2 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 951 69 13 0 41 5 1 9 Arkansas 289 61 9 4 17 28 0 3 California 6,725 393 32 14 123 152 8 64 Colorado 505 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,152 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 246 3 0 0 0 2 1 0 Hawaii 315 18 3 0 8 5 2 0 Idaho 257 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 233 54 14 1 24 12 0 3 Kansas 224 46 7 4 12 17 0 6 Kentucky 433 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 636 78 30 0 46 0 0 2 Missouri 464 75 16 4 31 19 1 4 Montana 112 13 4 2 1 5 0 1 N. Mariana Islands 69 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,055 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,542 154 18 11 47 59 5 14 North Carolina 1,032 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 422 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 655 83 6 5 17 47 0 8 Rhode Island 92 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,200 295 63 23 62 122 1 24 Utah 513 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 834 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 56 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,149 4,140 618 182 1,374 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B3. BDE-100 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 234,237 6,025 9,791 59,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,237,740 1,790,743 878,262 34,828,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B4. BDE-153 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 49 9 3 2 2 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 951 69 13 0 41 5 1 9 Arkansas 289 61 9 4 17 28 0 3 California 6,725 393 32 14 123 152 8 64 Colorado 505 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,152 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 246 3 0 0 0 2 1 0 Hawaii 315 18 3 0 8 5 2 0 Idaho 257 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 233 54 14 1 24 12 0 3 Kansas 224 46 7 4 12 17 0 6 Kentucky 433 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 636 78 30 0 46 0 0 2 Missouri 464 75 16 4 31 19 1 4 Montana 112 13 4 2 1 5 0 1 N. Mariana Islands 69 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,055 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,542 154 18 11 47 59 5 14 North Carolina 1,032 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 422 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 655 83 6 5 17 47 0 8 Rhode Island 92 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,190 295 63 23 62 122 1 24 Utah 513 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 834 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 56 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,139 4,140 618 182 1,374 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B4. BDE-153 - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 234,237 6,025 9,791 59,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,237,740 1,790,743 878,262 34,828,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B5. Dimethoate - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 49 9 3 2 2 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 951 69 13 0 41 5 1 9 Arkansas 289 61 9 4 17 28 0 3 California 6,725 393 32 14 123 152 8 64 Colorado 505 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,152 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 246 3 0 0 0 2 1 0 Hawaii 315 18 3 0 8 5 2 0 Idaho 257 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 233 54 14 1 24 12 0 3 Kansas 224 46 7 4 12 17 0 6 Kentucky 433 107 2 4 10 86 1 4 Louisiana 607 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 636 78 30 0 46 0 0 2 Missouri 464 75 16 4 31 19 1 4 Montana 112 13 4 2 1 5 0 1 N. Mariana Islands 69 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,055 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,542 154 18 11 47 59 5 14 North Carolina 1,032 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 422 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 655 83 6 5 17 47 0 8 Rhode Island 92 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,200 295 63 23 62 122 1 24 Utah 513 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 834 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 56 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,150 4,140 618 182 1,374 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B5. Dimethoate - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 234,237 6,025 9,791 59,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,237,740 1,790,743 878,262 34,828,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B6. 1,3-Dinitrobenzene - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 48 8 3 2 1 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 952 69 13 0 41 5 1 9 Arkansas 290 61 9 4 17 28 0 3 California 6,724 393 32 14 123 152 8 64 Colorado 503 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,155 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 245 3 0 0 0 2 1 0 Hawaii 313 18 3 0 8 5 2 0 Idaho 256 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 234 54 14 1 24 12 0 3 Kansas 226 46 7 4 12 17 0 6 Kentucky 432 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 635 78 30 0 46 0 0 2 Missouri 463 75 16 4 31 19 1 4 Montana 111 13 4 2 1 5 0 1 N. Mariana Islands 68 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,058 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,538 154 18 11 47 59 5 14 North Carolina 1,029 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 434 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 645 83 6 5 17 47 0 8 Rhode Island 91 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,199 295 63 23 62 122 1 24 Utah 514 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 844 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 57 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,152 4,139 618 182 1,373 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 222,237 6,025 9,791 47,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,225,740 1,790,743 878,262 34,816,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level. 

## Table B6. 1,3-Dinitrobenzene - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by

Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B7. HBB - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 49 9 3 2 2 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 951 69 13 0 41 5 1 9 Arkansas 289 61 9 4 17 28 0 3 California 6,725 393 32 14 123 152 8 64 Colorado 505 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,152 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 246 3 0 0 0 2 1 0 Hawaii 315 18 3 0 8 5 2 0 Idaho 257 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 233 54 14 1 24 12 0 3 Kansas 224 46 7 4 12 17 0 6 Kentucky 433 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 636 78 30 0 46 0 0 2 Missouri 464 75 16 4 31 19 1 4 Montana 112 13 4 2 1 5 0 1 N. Mariana Islands 69 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,055 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,542 154 18 11 47 59 5 14 North Carolina 1,032 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 422 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 655 83 6 5 17 47 0 8 Rhode Island 92 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,194 295 63 23 62 122 1 24 Utah 513 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 834 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 56 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,143 4,140 618 182 1,374 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B7. HBB - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 234,237 6,025 9,791 59,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,237,740 1,790,743 878,262 34,828,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B8. RDX - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 48 8 3 2 1 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 952 69 13 0 41 5 1 9 Arkansas 290 61 9 4 17 28 0 3 California 6,724 393 32 14 123 152 8 64 Colorado 503 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,155 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 245 3 0 0 0 2 1 0 Hawaii 313 18 3 0 8 5 2 0 Idaho 256 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 234 54 14 1 24 12 0 3 Kansas 226 46 7 4 12 17 0 6 Kentucky 432 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 635 78 30 0 46 0 0 2 Missouri 463 75 16 4 31 19 1 4 Montana 111 13 4 2 1 5 0 1 N. Mariana Islands 68 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,058 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,538 154 18 11 47 59 5 14 North Carolina 1,029 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 434 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 645 83 6 5 17 47 0 8 Rhode Island 91 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,198 295 63 23 62 122 1 24 Utah 514 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 843 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 57 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,150 4,139 618 182 1,373 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B8. RDX - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 222,237 6,025 9,791 47,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,225,740 1,790,743 878,262 34,816,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B9. Terbufos Sulfone - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 49 9 3 2 2 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 951 69 13 0 41 5 1 9 Arkansas 289 61 9 4 17 28 0 3 California 6,725 393 32 14 123 152 8 64 Colorado 505 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,152 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 246 3 0 0 0 2 1 0 Hawaii 315 18 3 0 8 5 2 0 Idaho 257 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 233 54 14 1 24 12 0 3 Kansas 224 46 7 4 12 17 0 6 Kentucky 433 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 636 78 30 0 46 0 0 2 Missouri 464 75 16 4 31 19 1 4 Montana 112 13 4 2 1 5 0 1 N. Mariana Islands 69 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,055 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,542 154 18 11 47 59 5 14 North Carolina 1,032 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 422 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 655 83 6 5 17 47 0 8 Rhode Island 92 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,200 295 63 23 62 122 1 24 Utah 513 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 834 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 56 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,149 4,140 618 182 1,374 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 234,237 6,025 9,791 59,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,237,740 1,790,743 878,262 34,828,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level. 

## Table B9. Terbufos Sulfone - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by

Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B10. TNT - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 946 120 13 3 36 62 0 6 Alaska 48 8 3 2 1 1 0 1 American Samoa 4 1 0 0 0 1 0 0 Arizona 952 69 13 0 41 5 1 9 Arkansas 290 61 9 4 17 28 0 3 California 6,724 393 32 14 123 152 8 64 Colorado 503 68 5 6 13 34 0 10 Connecticut 329 41 5 1 7 23 0 5 Delaware 106 10 4 0 2 1 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 1,155 231 28 0 161 7 23 12 Georgia 570 110 14 5 27 51 1 12 Guam 245 3 0 0 0 2 1 0 Hawaii 313 18 3 0 8 5 2 0 Idaho 256 22 7 0 13 1 0 1 Illinois 839 141 22 5 61 42 3 8 Indiana 399 99 16 2 56 18 1 6 Iowa 234 54 14 1 24 12 0 3 Kansas 226 46 7 4 12 17 0 6 Kentucky 432 107 2 4 10 86 1 4 Louisiana 606 92 25 3 36 21 3 4 Maine 89 19 4 2 3 9 0 1 Maryland 180 38 7 2 13 12 1 3 Massachusetts 965 126 9 3 55 50 1 8 Michigan 393 77 21 2 18 29 2 5 Minnesota 356 91 15 1 64 9 0 2 Mississippi 635 78 30 0 46 0 0 2 Missouri 463 75 16 4 31 19 1 4 Montana 111 13 4 2 1 5 0 1 N. Mariana Islands 68 2 1 0 1 0 0 0 Navajo Nation 12 2 1 0 1 0 0 0 Nebraska 238 22 8 0 10 2 0 2 Nevada 184 15 4 1 4 2 0 4 New Hampshire 155 24 5 1 4 13 0 1 New Jersey 1,058 131 14 1 55 49 1 11 New Mexico 331 32 7 1 18 5 1 0 New York 1,538 154 18 11 47 59 5 14 North Carolina 1,029 126 16 5 27 65 1 12 North Dakota 50 12 2 1 3 6 0 0 Ohio 525 153 20 5 59 58 1 10 Oklahoma 434 62 6 8 11 34 0 3 Oregon 365 55 6 4 10 30 0 5 Pennsylvania 1,218 171 24 13 24 92 0 18 Puerto Rico 645 83 6 5 17 47 0 8 Rhode Island 91 13 2 0 4 5 0 2 South Carolina 321 63 6 3 8 41 0 5 South Dakota 87 15 4 1 3 6 0 1 Tennessee 569 121 5 8 16 87 1 4 Texas 2,199 295 63 23 62 122 1 24 Utah 514 54 6 2 14 25 0 7 Vermont 46 11 3 2 0 6 0 0 Virgin Islands 20 4 2 0 0 2 0 0 Virginia 409 73 9 6 4 43 0 11 Washington 843 93 18 3 46 20 2 4 West Virginia 142 36 3 6 3 22 0 2 Wisconsin 561 78 19 1 38 16 1 3 Wyoming 57 11 3 0 1 7 0 0 Tribes - Region 1 4 1 0 0 0 1 0 0 Tribes - Region 5 10 4 3 0 1 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 0 Tribes - Region 8 6 2 0 1 1 0 0 0 Tribes - Region 9 45 9 6 0 2 1 0 0 Total 32,151 4,139 618 182 1,373 1,568 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B10. TNT - UCMR 2 Assessment Monitoring Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 4,249,148 64,214 15,859 850,382 1,612,450 0 1,706,245 Alaska 222,237 6,025 9,791 47,290 23,965 0 135,166 American Samoa 45,000 0 0 0 45,000 0 0 Arizona 4,417,574 32,953 0 999,514 110,587 675,445 2,599,075 Arkansas 1,771,814 31,449 19,189 395,797 638,748 0 686,632 California 32,516,672 101,399 70,338 3,738,533 6,626,442 1,088,908 20,891,052 Colorado 4,395,410 12,154 13,190 312,380 1,020,990 0 3,036,696 Connecticut 2,423,307 6,961 7,784 101,145 929,609 0 1,377,809 Delaware 550,332 14,255 0 54,443 36,130 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 15,964,524 85,230 0 5,601,752 190,650 7,266,168 2,820,724 Georgia 6,323,497 30,214 19,473 555,035 1,594,334 163,688 3,960,753 Guam 136,301 0 0 0 36,300 100,001 0 Hawaii 1,168,403 14,938 0 237,807 128,935 786,723 0 Idaho 598,638 20,705 0 377,881 14,052 0 186,000 Illinois 7,910,559 62,240 31,607 1,237,820 1,377,669 405,228 4,795,996 Indiana 3,833,462 53,832 8,150 1,343,907 460,953 113,400 1,853,220 Iowa 1,669,054 34,873 7,782 635,226 435,492 0 555,682 Kansas 1,903,624 14,044 15,781 288,095 327,403 0 1,258,301 Kentucky 4,050,273 6,419 21,540 145,399 2,190,482 85,697 1,600,737 Louisiana 3,411,211 100,823 8,085 762,163 705,285 663,655 1,171,200 Maine 368,811 10,566 8,770 43,690 192,225 0 113,560 Maryland 4,493,237 9,908 6,123 346,418 348,121 249,600 3,533,067 Massachusetts 7,942,671 43,421 14,171 1,317,567 1,768,248 159,180 4,640,084 Michigan 5,866,881 54,175 12,964 366,966 859,317 283,846 4,289,613 Minnesota 3,092,542 38,944 4,960 1,707,947 406,914 0 933,777 Mississippi 1,418,405 86,727 0 988,496 0 0 343,182 Missouri 3,711,957 49,173 19,101 600,252 449,297 223,971 2,370,164 Montana 376,922 8,734 8,778 72,215 183,824 0 103,371 N. Mariana Islands 72,737 1,081 0 71,656 0 0 0 Navajo Nation 19,080 836 0 18,244 0 0 0 Nebraska 998,770 26,423 0 219,594 37,864 0 714,889 Nevada 1,999,825 13,712 8,323 59,000 73,095 0 1,845,695 New Hampshire 562,737 8,516 10,000 86,706 305,451 0 152,064 New Jersey 7,116,424 60,693 3,400 1,156,623 1,666,422 115,378 4,113,907 New Mexico 1,152,067 16,238 8,256 501,653 172,567 453,353 0 New York 14,764,779 35,519 44,587 1,371,569 1,657,155 1,682,822 9,973,127 North Carolina 5,366,551 37,318 18,964 580,495 1,974,056 108,666 2,647,052 North Dakota 350,292 5,414 2,694 78,529 263,655 0 0 Ohio 8,788,460 64,492 31,964 1,498,349 1,822,242 123,850 5,247,564 Oklahoma 2,491,284 10,318 31,117 241,483 950,915 0 1,257,451 Oregon 2,413,155 13,140 24,170 188,470 830,806 0 1,356,569 Pennsylvania 8,692,491 58,224 57,237 425,487 2,978,041 0 5,173,502 Puerto Rico 5,552,363 20,268 20,177 384,807 1,688,215 0 3,438,896 Rhode Island 911,235 1,812 0 107,302 250,585 0 551,536 South Carolina 2,785,309 14,508 19,828 180,888 1,218,197 0 1,351,888 South Dakota 349,953 10,139 1,592 43,056 167,166 0 128,000 Tennessee 4,625,703 22,345 49,153 428,243 2,499,282 687,096 939,584 Texas 18,832,904 189,890 115,111 1,429,442 3,795,822 1,253,442 12,049,197 Utah 2,403,787 20,075 15,000 274,446 934,364 0 1,159,902 Vermont 196,255 5,245 5,830 0 185,180 0 0 Virgin Islands 67,889 2,550 0 0 65,339 0 0 Virginia 4,635,684 11,756 31,277 98,415 1,285,803 0 3,208,433 Washington 4,265,055 47,921 18,679 1,255,343 756,649 374,556 1,811,906 West Virginia 958,526 8,711 26,897 65,669 527,486 0 329,764 Wisconsin 2,806,236 59,710 8,550 842,048 620,506 205,247 1,070,175 Wyoming 296,668 6,591 0 24,999 265,078 0 0 Tribes - Region 1 41,000 0 0 0 41,000 0 0 Tribes - Region 5 18,788 4,068 0 14,720 0 0 0 Tribes - Region 6 0 0 0 0 0 0 0 Tribes - Region 8 12,160 0 2,020 10,140 0 0 0 Tribes - Region 9 62,055 18,855 0 31,200 12,000 0 0 Total 229,225,740 1,790,743 878,262 34,816,693 49,758,358 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B11. Acetochlor - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,347 154 13 28 19 22 8 64 Colorado 159 26 3 9 1 3 0 10 Connecticut 84 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 433 79 11 1 31 1 23 12 Georgia 170 31 6 5 2 5 1 12 Guam 219 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 212 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 141 24 4 2 4 5 1 8 Michigan 146 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 96 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 857 53 8 14 6 6 5 14 North Carolina 210 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 333 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 779 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 18 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 253 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 4 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,193 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B11. Acetochlor - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B12. Acetochlor ESA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,351 154 13 28 19 22 8 64 Colorado 158 26 3 9 1 3 0 10 Connecticut 83 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 432 79 11 1 31 1 23 12 Georgia 169 31 6 5 2 5 1 12 Guam 220 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 209 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 135 24 4 2 4 5 1 8 Michigan 145 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 95 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 848 53 8 14 6 6 5 14 North Carolina 209 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 334 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 776 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 17 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 241 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 3 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,157 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B12. Acetochlor ESA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B13. Acetochlor OA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,351 154 13 28 19 22 8 64 Colorado 158 26 3 9 1 3 0 10 Connecticut 83 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 432 79 11 1 31 1 23 12 Georgia 169 31 6 5 2 5 1 12 Guam 220 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 209 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 135 24 4 2 4 5 1 8 Michigan 145 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 95 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 848 53 8 14 6 6 5 14 North Carolina 209 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 334 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 776 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 17 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 241 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 3 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,157 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B13. Acetochlor OA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B14. Alachlor - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,347 154 13 28 19 22 8 64 Colorado 159 26 3 9 1 3 0 10 Connecticut 84 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 433 79 11 1 31 1 23 12 Georgia 170 31 6 5 2 5 1 12 Guam 219 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 212 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 141 24 4 2 4 5 1 8 Michigan 146 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 96 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 857 53 8 14 6 6 5 14 North Carolina 210 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 333 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 779 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 18 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 253 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 4 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,193 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B14. Alachlor - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B15. Alachlor ESA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,350 154 13 28 19 22 8 64 Colorado 158 26 3 9 1 3 0 10 Connecticut 83 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 432 79 11 1 31 1 23 12 Georgia 169 31 6 5 2 5 1 12 Guam 220 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 209 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 135 24 4 2 4 5 1 8 Michigan 145 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 95 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 848 53 8 14 6 6 5 14 North Carolina 209 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 334 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 776 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 17 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 241 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 3 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,156 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B15. Alachlor ESA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B16. Alachlor OA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,351 154 13 28 19 22 8 64 Colorado 158 26 3 9 1 3 0 10 Connecticut 83 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 432 79 11 1 31 1 23 12 Georgia 169 31 6 5 2 5 1 12 Guam 220 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 209 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 135 24 4 2 4 5 1 8 Michigan 145 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 95 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 848 53 8 14 6 6 5 14 North Carolina 209 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 334 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 776 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 17 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 241 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 3 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,157 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B16. Alachlor OA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B17. Metolachlor - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,347 154 13 28 19 22 8 64 Colorado 159 26 3 9 1 3 0 10 Connecticut 83 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 433 79 11 1 31 1 23 12 Georgia 170 31 6 5 2 5 1 12 Guam 219 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 212 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 141 24 4 2 4 5 1 8 Michigan 146 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 96 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 857 53 8 14 6 6 5 14 North Carolina 210 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 333 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 779 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 18 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 253 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 4 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,192 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B17. Metolachlor - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B18. Metolachlor ESA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,351 154 13 28 19 22 8 64 Colorado 158 26 3 9 1 3 0 10 Connecticut 83 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 432 79 11 1 31 1 23 12 Georgia 169 31 6 5 2 5 1 12 Guam 220 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 209 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 135 24 4 2 4 5 1 8 Michigan 145 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 95 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 848 53 8 14 6 6 5 14 North Carolina 209 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 334 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 776 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 17 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 241 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 3 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,157 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B18. Metolachlor ESA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B19. Metolachlor OA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 147 20 4 2 3 5 0 6 Alaska 58 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 382 19 4 2 3 0 1 9 Arkansas 68 13 3 3 2 2 0 3 California 3,351 154 13 28 19 22 8 64 Colorado 158 26 3 9 1 3 0 10 Connecticut 83 12 3 1 1 2 0 5 Delaware 83 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 432 79 11 1 31 1 23 12 Georgia 169 31 6 5 2 5 1 12 Guam 220 1 0 0 0 0 1 0 Hawaii 140 4 1 0 1 0 2 0 Idaho 67 9 3 3 2 0 0 1 Illinois 270 35 7 5 4 8 3 8 Indiana 109 21 5 2 5 2 1 6 Iowa 82 15 5 2 3 2 0 3 Kansas 76 16 3 5 1 1 0 6 Kentucky 83 17 0 4 0 8 1 4 Louisiana 209 22 8 2 3 2 3 4 Maine 22 6 2 2 0 1 0 1 Maryland 60 13 3 3 2 1 1 3 Massachusetts 135 24 4 2 4 5 1 8 Michigan 145 23 9 2 2 3 2 5 Minnesota 59 18 6 1 7 2 0 2 Mississippi 82 15 10 0 3 0 0 2 Missouri 95 20 6 4 3 2 1 4 Montana 24 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 14 3 2 0 1 0 0 0 Nebraska 45 7 3 1 1 0 0 2 Nevada 98 8 2 1 0 1 0 4 New Hampshire 17 6 3 1 0 1 0 1 New Jersey 257 26 6 0 4 4 1 11 New Mexico 110 8 3 2 2 0 1 0 New York 848 53 8 14 6 6 5 14 North Carolina 209 35 7 5 3 7 1 12 North Dakota 14 4 1 2 0 1 0 0 Ohio 152 36 7 5 7 6 1 10 Oklahoma 83 19 3 9 1 3 0 3 Oregon 84 17 3 6 0 3 0 5 Pennsylvania 334 51 10 14 0 9 0 18 Puerto Rico 275 27 2 10 2 5 0 8 Rhode Island 18 4 1 0 0 1 0 2 South Carolina 70 16 3 3 1 4 0 5 South Dakota 32 9 2 5 0 1 0 1 Tennessee 114 23 1 7 2 8 1 4 Texas 776 96 23 27 6 15 1 24 Utah 142 16 2 3 1 3 0 7 Vermont 17 5 1 3 0 1 0 0 Virgin Islands 2 1 1 0 0 0 0 0 Virginia 158 27 4 7 0 5 0 11 Washington 241 29 8 4 8 3 2 4 West Virginia 46 12 1 7 0 2 0 2 Wisconsin 149 17 8 0 3 2 1 3 Wyoming 16 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 3 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 16 2 0 2 0 0 0 0 Total 11,157 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B19. Metolachlor OA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B20. NDBA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 270 20 4 2 3 5 0 6 Alaska 97 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 753 19 4 2 3 0 1 9 Arkansas 116 13 3 3 2 2 0 3 California 4,394 154 13 28 19 22 8 64 Colorado 319 26 3 9 1 3 0 10 Connecticut 165 12 3 1 1 2 0 5 Delaware 117 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 793 79 11 1 31 1 23 12 Georgia 315 31 6 5 2 5 1 12 Guam 233 1 0 0 0 0 1 0 Hawaii 161 4 1 0 1 0 2 0 Idaho 109 9 3 3 2 0 0 1 Illinois 392 35 7 5 4 8 3 8 Indiana 203 21 5 2 5 2 1 6 Iowa 130 15 5 2 3 2 0 3 Kansas 140 16 3 5 1 1 0 6 Kentucky 156 17 0 4 0 8 1 4 Louisiana 302 22 8 2 3 2 3 4 Maine 39 6 2 2 0 1 0 1 Maryland 120 13 3 3 2 1 1 3 Massachusetts 221 24 4 2 4 5 1 8 Michigan 255 23 9 2 2 3 2 5 Minnesota 103 18 6 1 7 2 0 2 Mississippi 114 15 10 0 3 0 0 2 Missouri 167 20 6 4 3 2 1 4 Montana 48 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 30 3 2 0 1 0 0 0 Nebraska 71 7 3 1 1 0 0 2 Nevada 147 8 2 1 0 1 0 4 New Hampshire 31 6 3 1 0 1 0 1 New Jersey 375 26 6 0 4 4 1 11 New Mexico 132 8 3 2 2 0 1 0 New York 1,540 53 8 14 6 6 5 14 North Carolina 355 35 7 5 3 7 1 12 North Dakota 28 4 1 2 0 1 0 0 Ohio 297 36 7 5 7 6 1 10 Oklahoma 158 19 3 9 1 3 0 3 Oregon 147 17 3 6 0 3 0 5 Pennsylvania 656 51 10 14 0 9 0 18 Puerto Rico 569 27 2 10 2 5 0 8 Rhode Island 30 4 1 0 0 1 0 2 South Carolina 140 16 3 3 1 4 0 5 South Dakota 62 9 2 5 0 1 0 1 Tennessee 226 23 1 7 2 8 1 4 Texas 1,627 96 23 27 6 15 1 24 Utah 200 16 2 3 1 3 0 7 Vermont 36 5 1 3 0 1 0 0 Virgin Islands 4 1 1 0 0 0 0 0 Virginia 285 27 4 7 0 5 0 11 Washington 350 29 8 4 8 3 2 4 West Virginia 86 12 1 7 0 2 0 2 Wisconsin 214 17 8 0 3 2 1 3 Wyoming 33 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 8 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 24 2 0 2 0 0 0 0 Total 18,101 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B20. NDBA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B21. NDEA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 270 20 4 2 3 5 0 6 Alaska 97 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 753 19 4 2 3 0 1 9 Arkansas 116 13 3 3 2 2 0 3 California 4,382 154 13 28 19 22 8 64 Colorado 319 26 3 9 1 3 0 10 Connecticut 165 12 3 1 1 2 0 5 Delaware 117 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 793 79 11 1 31 1 23 12 Georgia 315 31 6 5 2 5 1 12 Guam 233 1 0 0 0 0 1 0 Hawaii 161 4 1 0 1 0 2 0 Idaho 109 9 3 3 2 0 0 1 Illinois 392 35 7 5 4 8 3 8 Indiana 203 21 5 2 5 2 1 6 Iowa 130 15 5 2 3 2 0 3 Kansas 140 16 3 5 1 1 0 6 Kentucky 156 17 0 4 0 8 1 4 Louisiana 302 22 8 2 3 2 3 4 Maine 39 6 2 2 0 1 0 1 Maryland 120 13 3 3 2 1 1 3 Massachusetts 221 24 4 2 4 5 1 8 Michigan 255 23 9 2 2 3 2 5 Minnesota 103 18 6 1 7 2 0 2 Mississippi 114 15 10 0 3 0 0 2 Missouri 167 20 6 4 3 2 1 4 Montana 48 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 30 3 2 0 1 0 0 0 Nebraska 71 7 3 1 1 0 0 2 Nevada 147 8 2 1 0 1 0 4 New Hampshire 31 6 3 1 0 1 0 1 New Jersey 375 26 6 0 4 4 1 11 New Mexico 132 8 3 2 2 0 1 0 New York 1,540 53 8 14 6 6 5 14 North Carolina 355 35 7 5 3 7 1 12 North Dakota 28 4 1 2 0 1 0 0 Ohio 297 36 7 5 7 6 1 10 Oklahoma 158 19 3 9 1 3 0 3 Oregon 147 17 3 6 0 3 0 5 Pennsylvania 656 51 10 14 0 9 0 18 Puerto Rico 569 27 2 10 2 5 0 8 Rhode Island 30 4 1 0 0 1 0 2 South Carolina 140 16 3 3 1 4 0 5 South Dakota 62 9 2 5 0 1 0 1 Tennessee 226 23 1 7 2 8 1 4 Texas 1,634 96 23 27 6 15 1 24 Utah 200 16 2 3 1 3 0 7 Vermont 36 5 1 3 0 1 0 0 Virgin Islands 4 1 1 0 0 0 0 0 Virginia 285 27 4 7 0 5 0 11 Washington 350 29 8 4 8 3 2 4 West Virginia 86 12 1 7 0 2 0 2 Wisconsin 214 17 8 0 3 2 1 3 Wyoming 33 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 8 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 24 2 0 2 0 0 0 0 Total 18,096 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B21. NDEA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B22. NDMA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 270 20 4 2 3 5 0 6 Alaska 97 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 753 19 4 2 3 0 1 9 Arkansas 116 13 3 3 2 2 0 3 California 4,392 154 13 28 19 22 8 64 Colorado 319 26 3 9 1 3 0 10 Connecticut 165 12 3 1 1 2 0 5 Delaware 117 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 793 79 11 1 31 1 23 12 Georgia 315 31 6 5 2 5 1 12 Guam 233 1 0 0 0 0 1 0 Hawaii 161 4 1 0 1 0 2 0 Idaho 109 9 3 3 2 0 0 1 Illinois 392 35 7 5 4 8 3 8 Indiana 203 21 5 2 5 2 1 6 Iowa 130 15 5 2 3 2 0 3 Kansas 140 16 3 5 1 1 0 6 Kentucky 156 17 0 4 0 8 1 4 Louisiana 302 22 8 2 3 2 3 4 Maine 39 6 2 2 0 1 0 1 Maryland 120 13 3 3 2 1 1 3 Massachusetts 220 24 4 2 4 5 1 8 Michigan 255 23 9 2 2 3 2 5 Minnesota 103 18 6 1 7 2 0 2 Mississippi 114 15 10 0 3 0 0 2 Missouri 167 20 6 4 3 2 1 4 Montana 48 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 30 3 2 0 1 0 0 0 Nebraska 71 7 3 1 1 0 0 2 Nevada 147 8 2 1 0 1 0 4 New Hampshire 31 6 3 1 0 1 0 1 New Jersey 375 26 6 0 4 4 1 11 New Mexico 132 8 3 2 2 0 1 0 New York 1,540 53 8 14 6 6 5 14 North Carolina 355 35 7 5 3 7 1 12 North Dakota 28 4 1 2 0 1 0 0 Ohio 297 36 7 5 7 6 1 10 Oklahoma 158 19 3 9 1 3 0 3 Oregon 147 17 3 6 0 3 0 5 Pennsylvania 656 51 10 14 0 9 0 18 Puerto Rico 569 27 2 10 2 5 0 8 Rhode Island 30 4 1 0 0 1 0 2 South Carolina 140 16 3 3 1 4 0 5 South Dakota 62 9 2 5 0 1 0 1 Tennessee 226 23 1 7 2 8 1 4 Texas 1,627 96 23 27 6 15 1 24 Utah 200 16 2 3 1 3 0 7 Vermont 36 5 1 3 0 1 0 0 Virgin Islands 4 1 1 0 0 0 0 0 Virginia 285 27 4 7 0 5 0 11 Washington 350 29 8 4 8 3 2 4 West Virginia 86 12 1 7 0 2 0 2 Wisconsin 214 17 8 0 3 2 1 3 Wyoming 33 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 8 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 24 2 0 2 0 0 0 0 Total 18,098 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B22. NDMA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B23. NDPA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 270 20 4 2 3 5 0 6 Alaska 97 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 753 19 4 2 3 0 1 9 Arkansas 116 13 3 3 2 2 0 3 California 4,394 154 13 28 19 22 8 64 Colorado 319 26 3 9 1 3 0 10 Connecticut 165 12 3 1 1 2 0 5 Delaware 117 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 793 79 11 1 31 1 23 12 Georgia 315 31 6 5 2 5 1 12 Guam 233 1 0 0 0 0 1 0 Hawaii 161 4 1 0 1 0 2 0 Idaho 109 9 3 3 2 0 0 1 Illinois 392 35 7 5 4 8 3 8 Indiana 203 21 5 2 5 2 1 6 Iowa 130 15 5 2 3 2 0 3 Kansas 140 16 3 5 1 1 0 6 Kentucky 156 17 0 4 0 8 1 4 Louisiana 302 22 8 2 3 2 3 4 Maine 39 6 2 2 0 1 0 1 Maryland 120 13 3 3 2 1 1 3 Massachusetts 221 24 4 2 4 5 1 8 Michigan 255 23 9 2 2 3 2 5 Minnesota 103 18 6 1 7 2 0 2 Mississippi 114 15 10 0 3 0 0 2 Missouri 167 20 6 4 3 2 1 4 Montana 48 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 30 3 2 0 1 0 0 0 Nebraska 71 7 3 1 1 0 0 2 Nevada 147 8 2 1 0 1 0 4 New Hampshire 31 6 3 1 0 1 0 1 New Jersey 375 26 6 0 4 4 1 11 New Mexico 132 8 3 2 2 0 1 0 New York 1,540 53 8 14 6 6 5 14 North Carolina 355 35 7 5 3 7 1 12 North Dakota 28 4 1 2 0 1 0 0 Ohio 297 36 7 5 7 6 1 10 Oklahoma 158 19 3 9 1 3 0 3 Oregon 147 17 3 6 0 3 0 5 Pennsylvania 656 51 10 14 0 9 0 18 Puerto Rico 569 27 2 10 2 5 0 8 Rhode Island 30 4 1 0 0 1 0 2 South Carolina 140 16 3 3 1 4 0 5 South Dakota 62 9 2 5 0 1 0 1 Tennessee 226 23 1 7 2 8 1 4 Texas 1,633 96 23 27 6 15 1 24 Utah 200 16 2 3 1 3 0 7 Vermont 36 5 1 3 0 1 0 0 Virgin Islands 4 1 1 0 0 0 0 0 Virginia 285 27 4 7 0 5 0 11 Washington 350 29 8 4 8 3 2 4 West Virginia 86 12 1 7 0 2 0 2 Wisconsin 214 17 8 0 3 2 1 3 Wyoming 33 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 8 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 24 2 0 2 0 0 0 0 Total 18,107 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B23. NDPA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B24. NMEA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 270 20 4 2 3 5 0 6 Alaska 97 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 753 19 4 2 3 0 1 9 Arkansas 116 13 3 3 2 2 0 3 California 4,394 154 13 28 19 22 8 64 Colorado 319 26 3 9 1 3 0 10 Connecticut 165 12 3 1 1 2 0 5 Delaware 117 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 793 79 11 1 31 1 23 12 Georgia 315 31 6 5 2 5 1 12 Guam 233 1 0 0 0 0 1 0 Hawaii 161 4 1 0 1 0 2 0 Idaho 109 9 3 3 2 0 0 1 Illinois 392 35 7 5 4 8 3 8 Indiana 203 21 5 2 5 2 1 6 Iowa 130 15 5 2 3 2 0 3 Kansas 140 16 3 5 1 1 0 6 Kentucky 156 17 0 4 0 8 1 4 Louisiana 302 22 8 2 3 2 3 4 Maine 39 6 2 2 0 1 0 1 Maryland 120 13 3 3 2 1 1 3 Massachusetts 221 24 4 2 4 5 1 8 Michigan 255 23 9 2 2 3 2 5 Minnesota 103 18 6 1 7 2 0 2 Mississippi 114 15 10 0 3 0 0 2 Missouri 167 20 6 4 3 2 1 4 Montana 48 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 30 3 2 0 1 0 0 0 Nebraska 71 7 3 1 1 0 0 2 Nevada 147 8 2 1 0 1 0 4 New Hampshire 31 6 3 1 0 1 0 1 New Jersey 375 26 6 0 4 4 1 11 New Mexico 132 8 3 2 2 0 1 0 New York 1,540 53 8 14 6 6 5 14 North Carolina 355 35 7 5 3 7 1 12 North Dakota 28 4 1 2 0 1 0 0 Ohio 297 36 7 5 7 6 1 10 Oklahoma 158 19 3 9 1 3 0 3 Oregon 147 17 3 6 0 3 0 5 Pennsylvania 656 51 10 14 0 9 0 18 Puerto Rico 569 27 2 10 2 5 0 8 Rhode Island 30 4 1 0 0 1 0 2 South Carolina 140 16 3 3 1 4 0 5 South Dakota 62 9 2 5 0 1 0 1 Tennessee 226 23 1 7 2 8 1 4 Texas 1,627 96 23 27 6 15 1 24 Utah 200 16 2 3 1 3 0 7 Vermont 36 5 1 3 0 1 0 0 Virgin Islands 4 1 1 0 0 0 0 0 Virginia 285 27 4 7 0 5 0 11 Washington 350 29 8 4 8 3 2 4 West Virginia 86 12 1 7 0 2 0 2 Wisconsin 214 17 8 0 3 2 1 3 Wyoming 33 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 8 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 24 2 0 2 0 0 0 0 Total 18,101 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B24. NMEA - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B25. NPYR - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Number of Samples Total

Number of Systems Number of

Small Systems (serving ≤ 10,000 people): Ground Water Number of

Small Systems (serving ≤ 10,000 people): Surface Water Number of

Large Systems (serving 10,001- 100,000 people): Ground Water Number of

Large Systems (serving 10,001- 100,000 people): Surface Water Number of Very

Large Systems (serving >100,000 people): Ground Water Number of Very

Large Systems (serving >100,000 people): Surface Water

Alabama 270 20 4 2 3 5 0 6 Alaska 97 9 1 7 0 0 0 1 American Samoa 0 0 0 0 0 0 0 0 Arizona 753 19 4 2 3 0 1 9 Arkansas 116 13 3 3 2 2 0 3 California 4,394 154 13 28 19 22 8 64 Colorado 319 26 3 9 1 3 0 10 Connecticut 165 12 3 1 1 2 0 5 Delaware 117 5 1 0 1 0 0 3 District of Columbia 8 1 0 0 0 0 0 1 Florida 793 79 11 1 31 1 23 12 Georgia 315 31 6 5 2 5 1 12 Guam 233 1 0 0 0 0 1 0 Hawaii 161 4 1 0 1 0 2 0 Idaho 109 9 3 3 2 0 0 1 Illinois 392 35 7 5 4 8 3 8 Indiana 203 21 5 2 5 2 1 6 Iowa 130 15 5 2 3 2 0 3 Kansas 140 16 3 5 1 1 0 6 Kentucky 156 17 0 4 0 8 1 4 Louisiana 302 22 8 2 3 2 3 4 Maine 39 6 2 2 0 1 0 1 Maryland 120 13 3 3 2 1 1 3 Massachusetts 221 24 4 2 4 5 1 8 Michigan 255 23 9 2 2 3 2 5 Minnesota 103 18 6 1 7 2 0 2 Mississippi 114 15 10 0 3 0 0 2 Missouri 167 20 6 4 3 2 1 4 Montana 48 7 2 4 0 0 0 1 N. Mariana Islands 0 0 0 0 0 0 0 0 Navajo Nation 30 3 2 0 1 0 0 0 Nebraska 71 7 3 1 1 0 0 2 Nevada 147 8 2 1 0 1 0 4 New Hampshire 31 6 3 1 0 1 0 1 New Jersey 375 26 6 0 4 4 1 11 New Mexico 132 8 3 2 2 0 1 0 New York 1,540 53 8 14 6 6 5 14 North Carolina 355 35 7 5 3 7 1 12 North Dakota 28 4 1 2 0 1 0 0 Ohio 297 36 7 5 7 6 1 10 Oklahoma 158 19 3 9 1 3 0 3 Oregon 147 17 3 6 0 3 0 5 Pennsylvania 656 51 10 14 0 9 0 18 Puerto Rico 569 27 2 10 2 5 0 8 Rhode Island 30 4 1 0 0 1 0 2 South Carolina 140 16 3 3 1 4 0 5 South Dakota 62 9 2 5 0 1 0 1 Tennessee 226 23 1 7 2 8 1 4 Texas 1,627 96 23 27 6 15 1 24 Utah 200 16 2 3 1 3 0 7 Vermont 36 5 1 3 0 1 0 0 Virgin Islands 4 1 1 0 0 0 0 0 Virginia 285 27 4 7 0 5 0 11 Washington 350 29 8 4 8 3 2 4 West Virginia 86 12 1 7 0 2 0 2 Wisconsin 214 17 8 0 3 2 1 3 Wyoming 33 4 0 3 0 1 0 0 Tribes - Region 1 0 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 0 Tribes - Region 6 8 2 2 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 0 Tribes - Region 9 24 2 0 2 0 0 0 0 Total 18,101 1,198 240 240 151 169 63 335
1 The UCMR data are not representative at the state-level.



## Page 1 of 2

## EPA-OGWDW

Appendix B. Summary of Systems and Population Served by State Occurrence Data from the UCMR 2

Table B25. NPYR - UCMR 2 Screening Survey Data - Number of Systems and Population Served by State

State 1 Total

Population Served Pop. Served by

Small Systems (serving ≤10,000 people): Ground Water Pop. Served by

Small Systems (serving ≤10,000 people): Surface Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Ground Water Pop. Served by

Large Systems (serving 10,001- 100,000 people): Surface Water Pop. Served by

Very Large Systems (serving >100,000 people): Ground Water Pop. Served by

Very Large Systems (serving >100,000 people): Surface Water

Alabama 2,040,600 17,259 9,693 103,109 204,295 0 1,706,245 Alaska 143,305 90 8,049 0 0 0 135,166 American Samoa 0 0 0 0 0 0 0 Arizona 3,403,868 14,319 1,729 113,300 0 675,445 2,599,075 Arkansas 845,459 11,365 8,930 85,674 52,858 0 686,632 California 24,372,007 29,816 49,813 1,008,796 1,303,622 1,088,908 20,891,052 Colorado 3,219,993 8,226 15,710 31,000 128,361 0 3,036,696 Connecticut 1,497,295 1,004 6,620 17,500 94,362 0 1,377,809 Delaware 484,765 4,383 0 34,878 0 0 445,504 District of Columbia 783,055 0 0 0 0 0 783,055 Florida 11,889,692 31,802 7,075 1,732,771 31,152 7,266,168 2,820,724 Georgia 4,397,366 9,885 12,463 39,543 211,034 163,688 3,960,753 Guam 100,001 0 0 0 0 100,001 0 Hawaii 854,836 4,958 0 63,155 0 786,723 0 Idaho 280,917 5,329 1,237 88,351 0 0 186,000 Illinois 5,680,520 22,938 20,358 71,451 364,550 405,228 4,795,996 Indiana 2,277,440 14,331 9,489 216,877 70,123 113,400 1,853,220 Iowa 805,109 14,756 7,369 146,216 81,086 0 555,682 Kansas 1,331,673 6,004 14,995 41,348 11,025 0 1,258,301 Kentucky 1,962,150 0 17,056 0 258,661 85,697 1,600,737 Louisiana 2,049,851 22,928 7,429 115,495 69,144 663,655 1,171,200 Maine 132,909 724 7,600 0 11,025 0 113,560 Maryland 3,874,592 6,534 7,390 64,801 13,200 249,600 3,533,067 Massachusetts 5,202,826 10,300 12,914 130,449 249,899 159,180 4,640,084 Michigan 4,826,722 12,746 12,269 97,711 130,537 283,846 4,289,613 Minnesota 1,400,744 10,862 7,501 300,404 148,200 0 933,777 Mississippi 424,022 31,538 0 49,302 0 0 343,182 Missouri 2,793,981 11,698 13,341 97,715 77,092 223,971 2,370,164 Montana 112,643 3,104 6,168 0 0 0 103,371 N. Mariana Islands 0 0 0 0 0 0 0 Navajo Nation 21,873 3,629 0 18,244 0 0 0 Nebraska 743,335 4,946 2,500 21,000 0 0 714,889 Nevada 1,908,764 6,832 237 0 56,000 0 1,845,695 New Hampshire 165,859 950 1,595 0 11,250 0 152,064 New Jersey 4,449,920 10,749 0 91,759 118,127 115,378 4,113,907 New Mexico 568,968 7,769 2,846 105,000 0 453,353 0 New York 12,173,772 8,634 35,158 248,594 225,437 1,682,822 9,973,127 North Carolina 3,220,020 15,311 26,493 111,438 311,061 108,666 2,647,052 North Dakota 92,952 1,099 1,254 0 90,599 0 0 Ohio 5,968,446 21,415 12,060 300,293 263,264 123,850 5,247,564 Oklahoma 1,432,777 6,402 25,003 15,435 128,486 0 1,257,451 Oregon 1,505,465 7,740 18,036 0 123,120 0 1,356,569 Pennsylvania 5,612,428 14,708 33,537 0 390,681 0 5,173,502 Puerto Rico 3,794,459 4,955 17,083 112,793 220,732 0 3,438,896 Rhode Island 613,600 355 0 0 61,709 0 551,536 South Carolina 1,604,882 8,549 10,201 53,122 181,122 0 1,351,888 South Dakota 152,210 811 3,162 0 20,237 0 128,000 Tennessee 2,104,138 8,587 31,013 66,568 371,290 687,096 939,584 Texas 14,372,970 60,963 89,693 228,445 691,230 1,253,442 12,049,197 Utah 1,362,703 8,500 9,345 24,000 160,956 0 1,159,902 Vermont 63,618 298 11,570 0 51,750 0 0 Virgin Islands 50 50 0 0 0 0 0 Virginia 3,377,005 3,451 21,232 0 143,889 0 3,208,433 Washington 2,706,556 15,667 6,360 404,649 93,417 374,556 1,811,906 West Virginia 434,635 424 26,216 0 78,231 0 329,764 Wisconsin 1,507,678 17,221 0 133,000 82,035 205,247 1,070,175 Wyoming 68,027 0 8,043 0 59,984 0 0 Tribes - Region 1 0 0 0 0 0 0 0 Tribes - Region 5 0 0 0 0 0 0 0 Tribes - Region 6 1,450 1,450 0 0 0 0 0 Tribes - Region 8 0 0 0 0 0 0 0 Tribes - Region 9 2,722 0 2,722 0 0 0 0 Total 157,219,620 548,364 660,557 6,584,184 7,444,830 17,269,919 124,711,765
1 The UCMR data are not representative at the state-level.



## Page 2 of 2

## EPA

- OGWDW Occurrence Da ta f rom the UC

MR 2



# Appendix C

Tabl e C1. RDX – Final UCMR 2 Assessment Monitoring Data – Summary of Samples and Detected Concentrations
Table C2. Ter bufos Sulfone – Final UCMR 2 Assessment Monitoring Data – Summary of Samples and Detected Concentrations
Table C3. Acetochlor ESA – Final UCMR 2 Screening Survey Data – Summary of Samples and Detected Concentrations
Table C4. Alachlor ESA – Final UCMR 2 Sc reening Survey Data – Summary of Samples and Detected Concentrations
Table C5. Metolachlor – Final UCMR 2 Screening Survey Data – Summary of Samples and Detected Concentrations
Table C6. Metolachlor ESA – Final UCMR 2 Screening Survey Data – Summary of Sam ples and Detected Concentrations
Table C7. Metolachlor OA – Final UCMR 2 Screening Survey Data – Summary of Samples and Detected Concentrations
Table C8. NDBA – Final UCMR 2 Screening Survey Data – Summary of Samples and Detected Concentrations
Table C9. N DEA – Final UCMR 2 Screening Survey Data – Summary of Samples and Detected Concentrations
Table C10. NDMA – Final UCMR 2 Screening Survey Data – Summary of Samples and Detected Concentrations
Table C11. NMEA – Final UCMR 2 Screening Survey Data – Summary o f Samples and Detected Concentrations
Table C12. NPYR – Final UCMR 2 Screening Survey Data – Summary of Samp les and Detected Concentrations

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C1a. RDX – UCMR 2 Assessment Monitoring Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,332 0 0.00% 0 0.00% 0 0.00%

Surface Water 919 0 0.00% 0 0.00% 0 0.00%
All Small Systems 3,251 0 0.00% 0 0.00% 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 0 0.00% 0 0.00% 0 0.00%

Surface Water 10,327 4 0.04% 0 0.00% 0 0.00%
All Large Systems 22,087 4 0.02% 0 0.00% 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,012 0 0.00% 0 0.00% 0 0.00%

Surface Water 4,800 0 0.00% 0 0.00% 0 0.00%
All Very Large Systems 6,812 0 0.00% 0 0.00% 0 0.00%
All Systems
All Water Systems 32,150 4 0.01% 0 0.00% 0 0.00%



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C1b. RDX – UCMR 2 Assessment Monitoring Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Small Systems ND ND ND ND ND
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water ND ND ND ND ND

Surface Water 1 1.1 1.1 1.1 1.1
All Large Systems 1 1.1 1.1 1.1 1.1
Census of Very Large Systems (serving > 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Very Large Systems ND ND ND ND ND
All Systems
All Water Systems 1 1.1 1.1 1.1 1.1

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C2a. Terbufos Sulfone – UCMR 2 Assessment Monitoring Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 2,328 0 0.00% 0 0.00% 0 0.00%

Surface Water 920 0 0.00% 0 0.00% 0 0.00%
All Small Systems 3,248 0 0.00% 0 0.00% 0 0.00%
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 11,760 1 0.01% 1 0.01% 1 0.01%

Surface Water 10,331 0 0.00% 0 0.00% 0 0.00%
All Large Systems 22,091 1 0.005% 1 0.005% 1 0.005%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,014 0 0.00% 0 0.00% 0 0.00%

Surface Water 4,796 0 0.00% 0 0.00% 0 0.00%
All Very Large Systems 6,810 0 0.00% 0 0.00% 0 0.00%
All Systems
All Water Systems 32,149 1 0.003% 1 0.003% 1 0.003%

D = No detection



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C2b. Terbufos Sulfone – UCMR 2 Assessment Monitoring Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Small Systems ND ND ND ND ND
Census of Large Systems (serving 10,001 - 100,000 people)

Ground Water 0.42 0.42 0.42 0.42 0.42

Surface Water ND ND ND ND ND
All Large Systems 0.42 0.42 0.42 0.42 0.42
Census of Very Large Systems (serving > 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Very Large Systems ND ND ND ND ND
All Systems
All Water Systems 0.42 0.42 0.42 0.42 0.42

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C3a. Acetochlor ESA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,035 1 0.10% 1 0.10% 1 0.10%
All Small Systems 1,821 1 0.05% 1 0.05% 1 0.05%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,170 0 0.00% 0 0.00% 0 0.00%
All Large Systems 2,551 0 0.00% 0 0.00% 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 0 0.00% 0 0.00% 0 0.00%

Surface Water 4,786 1 0.02% 1 0.02% 1 0.02%
All Very Large Systems 6,785 1 0.01% 1 0.01% 1 0.01%
All Systems
All Water Systems 11,157 2 0.02% 2 0.02% 2 0.02%



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C3b. Acetochlor ESA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water 1.10526 1.10526 1.10526 1.10526 1.10526
All Small Systems 1.10526 1.10526 1.10526 1.10526 1.10526
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Large Systems ND ND ND ND ND
Census of Very Large Systems (serving > 100,000 people)

Ground Water ND ND ND ND ND

Surface Water 1.2 1.2 1.2 1.2 1.2
All Very Large Systems 1.2 1.2 1.2 1.2 1.2
All Systems
All Water Systems 1.10526 1.15263 1.19053 1.19905 1.2

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C4a. Alachlor ESA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,035 3 0.29% 3 0.29% 3 0.29%
All Small Systems 1,821 3 0.16% 3 0.16% 3 0.16%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 1 0.07% 1 0.07% 1 0.07%

Surface Water 1,170 0 0.00% 0 0.00% 0 0.00%
All Large Systems 2,551 1 0.04% 1 0.04% 1 0.04%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 0 0.00% 0 0.00% 0 0.00%

Surface Water 4,785 1 0.02% 1 0.02% 1 0.02%
All Very Large Systems 6,784 1 0.01% 1 0.01% 1 0.01%
All Systems
All Water Systems 11,156 5 0.04% 5 0.04% 5 0.04%



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C4b. Alachlor ESA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water 1 1.2 1.2 1.2 1.2
All Small Systems 1 1.2 1.2 1.2 1.2
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1.06364 1.06364 1.06364 1.06364 1.06364

Surface Water ND ND ND ND ND
All Large Systems 1.06364 1.06364 1.06364 1.06364 1.06364
Census of Very Large Systems (serving > 100,000 people)

Ground Water ND ND ND ND ND

Surface Water 1.3 1.3 1.3 1.3 1.3
All Very Large Systems 1.3 1.3 1.3 1.3 1.3
All Systems
All Water Systems 1 1.2 1.3 1.3 1.3

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C5a. Metolachlor – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 788 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,040 2 0.19% 0 0.00% 0 0.00%
All Small Systems 1,828 2 0.11% 0 0.00% 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,392 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,178 0 0.00% 0 0.00% 0 0.00%
All Large Systems 2,570 0 0.00% 0 0.00% 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,010 0 0.00% 0 0.00% 0 0.00%

Surface Water 4,784 1 0.02% 0 0.00% 0 0.00%
All Very Large Systems 6,794 1 0.01% 0 0.00% 0 0.00%
All Systems
All Water Systems 11,192 3 0.03% 0 0.00% 0 0.00%

ND = No detection



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C5b. Metolachlor – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water 1.152 1.94218 2.57432 2.71655 2.73235
All Small Systems 1.152 1.94218 2.57432 2.71655 2.73235
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Large Systems ND ND ND ND ND
Census of Very Large Systems (serving > 100,000 people)

Ground Water ND ND ND ND ND

Surface Water 1.4 1.4 1.4 1.4 1.4
All Very Large Systems 1.4 1.4 1.4 1.4 1.4
All Systems
All Water Systems 1.152 1.4 2.46588 2.7057 2.73235

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C6a. Metolachlor ESA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 16 2.04% 0 0.00% 0 0.00%

Surface Water 1,035 5 0.48% 0 0.00% 0 0.00%
All Small Systems 1,821 21 1.15% 0 0.00% 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 4 0.29% 0 0.00% 0 0.00%

Surface Water 1,170 8 0.68% 0 0.00% 0 0.00%
All Large Systems 2,551 12 0.47% 0 0.00% 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 9 0.45% 0 0.00% 0 0.00%

Surface Water 4,786 10 0.21% 0 0.00% 0 0.00%
All Very Large Systems 6,785 19 0.28% 0 0.00% 0 0.00%
All Systems
All Water Systems 11,157 52 0.47% 0 0.00% 0 0.00%



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C6b. Metolachlor ESA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1.16 1.95 2.71137 3.78137 3.95455

Surface Water 1.02381 1.11739 1.4 1.4 1.4
All Small Systems 1.02381 1.8375 2.62273 3.72364 3.95455
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1.48261 1.87095 2.13864 2.20614 2.21364

Surface Water 1 1.1 1.3 1.3 1.3
All Large Systems 1 1.25 1.9451 2.18614 2.21364
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1.03 1.168 3.024 3.296 3.326

Surface Water 1.1 1.2 2.0 2.2 2.2
All Very Large Systems 1.03 1.188 2.711 3.258 3.326
All Systems
All Water Systems 1 1.44131 2.61986 3.63399 3.95455



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C7a. Metolachlor OA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 786 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,035 0 0.00% 0 0.00% 0 0.00%
All Small Systems 1,821 0 0.00% 0 0.00% 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,381 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,170 0 0.00% 0 0.00% 0 0.00%
All Large Systems 2,551 0 0.00% 0 0.00% 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 1,999 3 0.15% 0 0.00% 0 0.00%

Surface Water 4,786 0 0.00% 0 0.00% 0 0.00%
All Very Large Systems 6,785 3 0.04% 0 0.00% 0 0.00%
All Systems
All Water Systems 11,157 3 0.03% 0 0.00% 0 0.00%



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C7b. Metolachlor OA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Small Systems ND ND ND ND ND
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Large Systems ND ND ND ND ND
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2.502 3.078 3.447 3.53 3.539

Surface Water ND ND ND ND ND
All Very Large Systems 2.502 3.078 3.447 3.53 3.539
All Systems
All Water Systems 2.502 3.078 3.447 3.53 3.539

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C8a. NDBA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,237 3 0.24% 1 0.08% 0 0.00%

Surface Water 1,996 0 0.00% 0 0.00% 0 0.00%
All Small Systems 3,233 3 0.09% 1 0.03% 0 0.00%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 0 0.00% 0 0.00% 0 0.00%

Surface Water 2,091 0 0.00% 0 0.00% 0 0.00%
All Large Systems 4,023 0 0.00% 0 0.00% 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 3 0.10% 0 0.00% 0 0.00%

Surface Water 7,879 3 0.04% 0 0.00% 0 0.00%
All Very Large Systems 10,845 6 0.06% 0 0.00% 0 0.00%
All Systems
All Water Systems 18,101 9 0.05% 1 0.01% 0 0.00%

ND = No detection



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C8b. NDBA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 0.004 0.00629 0.01775 0.02033 0.02062

Surface Water ND ND ND ND ND
All Small Systems 0.004 0.00629 0.01775 0.02033 0.02062
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Large Systems ND ND ND ND ND
Census of Very Large Systems (serving > 100,000 people)

Ground Water 0.00442 0.00666 0.00877 0.00925 0.0093

Surface Water 0.0048 0.0092 0.0098 0.01 0.01
All Very Large Systems 0.00442 0.00793 0.00965 0.00997 0.01
All Systems
All Water Systems 0.004 0.00666 0.01212 0.01977 0.02062

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C9a. NDEA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 1 0.08% 1 0.08% 1 0.08%

Surface Water 1,996 0 0.00% 0 0.00% 0 0.00%
All Small Systems 3,233 1 0.03% 1 0.03% 1 0.03%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,920 3 0.16% 3 0.16% 3 0.16%

Surface Water 2,091 6 0.29% 6 0.29% 6 0.29%
All Large Systems 4,011 9 0.22% 9 0.22% 9 0.22%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,968 7 0.24% 7 0.24% 7 0.24%

Surface Water 7,884 29 0.37% 29 0.37% 29 0.37%
All Very Large Systems 10,852 36 0.33% 36 0.33% 36 0.33%
All Systems
All Water Systems 18,096 46 0.25% 46 0.25% 46 0.25%

ND = No detection



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C9b. NDEA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 0.009 0.009 0.009 0.009 0.009

Surface Water ND ND ND ND ND
All Small Systems 0.009 0.009 0.009 0.009 0.009
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 0.0051 0.0052 0.0061 0.0063 0.0063

Surface Water 0.0057 0.012 0.0435 0.0494 0.05
All Large Systems 0.0051 0.0086 0.0396 0.049 0.05
Census of Very Large Systems (serving > 100,000 people)

Ground Water 0.0053 0.0061 0.0126 0.0211 0.022

Surface Water 0.005 0.008 0.029 0.096 0.1
All Very Large Systems 0.005 0.007 0.027 0.095 0.1
All Systems
All Water Systems 0.005 0.007 0.031 0.093 0.1

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C10a. NDMA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 14 1.13% 14 1.13% 14 1.13%

Surface Water 1,996 326 16.33% 326 16.33% 326 16.33%
All Small Systems 3,233 340 10.52% 340 10.52% 340 10.52%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 48 2.48% 48 2.48% 48 2.48%

Surface Water 2,091 305 14.59% 305 14.59% 305 14.59%
All Large Systems 4,023 353 8.77% 353 8.77% 353 8.77%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 52 1.75% 52 1.75% 52 1.75%

Surface Water 7,876 1,116 14.17% 1,116 14.17% 1,116 14.17%
All Very Large Systems 10,842 1,168 10.77% 1,168 10.77% 1,168 10.77%
All Systems
All Water Systems 18,098 1,861 10.28% 1,861 10.28% 1,861 10.28%



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C10b. NDMA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 0.002 0.0036 0.0075 0.0092 0.0094

Surface Water 0.002 0.006 0.032 0.125 0.63
All Small Systems 0.002 0.006 0.031 0.122 0.63
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 0.002 0.004 0.005 0.01 0.01

Surface Water 0.002 0.0045 0.016 0.0523 0.0656
All Large Systems 0.002 0.0041 0.0152 0.0477 0.0656
Census of Very Large Systems (serving > 100,000 people)

Ground Water 0.002 0.00297 0.00522 0.01073 0.01343

Surface Water 0.002 0.004 0.015 0.043 0.094
All Very Large Systems 0.002 0.004 0.014 0.042 0.094
All Systems
All Water Systems 0.002 0.004 0.016 0.063 0.63



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C11a. NMEA – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,996 3 0.15% 3 0.15% 3 0.15%
All Small Systems 3,233 3 0.09% 3 0.09% 3 0.09%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 0 0.00% 0 0.00% 0 0.00%

Surface Water 2,091 0 0.00% 0 0.00% 0 0.00%
All Large Systems 4,023 0 0.00% 0 0.00% 0 0.00%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 0 0.00% 0 0.00% 0 0.00%

Surface Water 7,879 0 0.00% 0 0.00% 0 0.00%
All Very Large Systems 10,845 0 0.00% 0 0.00% 0 0.00%
All Systems
All Water Systems 18,101 3 0.02% 3 0.02% 3 0.02%

ND = No detection



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C11b. NMEA – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water 0.0036 0.0045 0.0048 0.0049 0.0049
All Small Systems 0.0036 0.0045 0.0048 0.0049 0.0049
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Large Systems ND ND ND ND ND
Census of Very Large Systems (serving > 100,000 people)

Ground Water ND ND ND ND ND

Surface Water ND ND ND ND ND
All Very Large Systems ND ND ND ND ND
All Systems
All Water Systems 0.0036 0.0045 0.0048 0.0049 0.0049

ND = No detection



# Page 2 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C12a. NPYR – UCMR 2 Screening Survey Data – Summary of Samples

Source Water Type Total Number of Samples Samples with

Detections: Number Samples with

Detections: Percent Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Number Samples with

Detections > 1⁄2 HRL (10.5 μg/L): Percent Samples with

Detections > HRL (21 μg/L): Number Samples with

Detections > HRL (21 μg/L): Percent

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water 1,237 0 0.00% 0 0.00% 0 0.00%

Surface Water 1,996 11 0.55% 11 0.55% 11 0.55%
All Small Systems 3,233 11 0.34% 11 0.34% 11 0.34%
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water 1,932 0 0.00% 0 0.00% 0 0.00%

Surface Water 2,091 7 0.33% 7 0.33% 7 0.33%
All Large Systems 4,023 7 0.17% 7 0.17% 7 0.17%
Census of Very Large Systems (serving > 100,000 people)

Ground Water 2,966 1 0.03% 1 0.03% 1 0.03%

Surface Water 7,879 22 0.28% 22 0.28% 22 0.28%
All Very Large Systems 10,845 23 0.21% 23 0.21% 23 0.21%
All Systems
All Water Systems 18,101 41 0.23% 41 0.23% 41 0.23%

ND = No detection



# Page 1 of 2

# EPA-OGWDW

Appendix C. Summary of Samples (Relative to the HRL) Occurrence Data from the UCMR 2

Table C12b. NPYR – UCMR 2 Screening Survey Data – Summary of Detected Concentrations

Source Water Type Concentration Value of Detections (μg/L): Minimum Concentration

Value of Detections (μg/L): Median Concentration

Value of Detections (μg/L): 90 th 

### Percentile Concentration Value of Detections (μg/L): 99 th 

### Percentile Concentration Value of Detections (μg/L): Maximum

Sample of Small Systems (serving ≤ 10,000 people)

Ground Water ND ND ND ND ND

Surface Water 0.00207 0.00284 0.005 0.00599 0.0061
All Small Systems 0.00207 0.00284 0.005 0.00599 0.0061
Sample of Large Systems (serving 10,001 - 100,000 people)

Ground Water ND ND ND ND ND

Surface Water 0.0022 0.0054 0.0078 0.0095 0.0097
All Large Systems 0.0022 0.0054 0.0078 0.0095 0.0097
Census of Very Large Systems (serving > 100,000 people)

Ground Water 0.0036 0.0036 0.0036 0.0036 0.0036

Surface Water 0.0021 0.0047 0.0137 0.0224 0.0238
All Very Large Systems 0.0021 0.0045 0.0130 0.0223 0.0238
All Systems
All Water Systems 0.00207 0.0039 0.0076 0.02116 0.0238

ND = No detection



# Page 2 of 2