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EO12866_UCMR3 Part 141 and 142_2040 AF10_draft FRN_20111028.docx 

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 141 and 142 

[Docket No. EPA-HQ-OW-2009-0090; FRL- ] 

RIN 2040-AF10

Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public 

Water Systems

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final Rule.

_______________________________________________________________________ 

SUMMARY: The 1996 amendments to the Safe Drinking Water Act (SDWA) require that the 

United States Environmental Protection Agency (EPA or the Agency) establish criteria for a 

program to monitor unregulated contaminants and publish a list of contaminants to be monitored 

every five years. This final rule meets the SDWA requirement by publishing the third 

Unregulated Contaminant Monitoring Regulation (i.e., UCMR 3), listing the unregulated 

contaminants to be monitored and addressing the requirements for such monitoring. This final 
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rule describes analytical methods to monitor for 28 UCMR 3 chemical contaminants and 

describes the monitoring for two viruses, for a total of 30 UCMR 3 contaminants. EPA is also 

requiring the monitoring of total chromium under the authority provided in the SDWA. UCMR 3 

provides EPA and other interested parties with scientifically valid data on the occurrence of these 

contaminants in drinking water, permitting the assessment of the number of people potentially 

being exposed and the levels of that exposure. These data are one of the primary sources of 

occurrence and exposure information the Agency uses to develop regulatory decisions for these 

contaminants. In addition, as part of an Expedited Methods Update, this rule finalizes 

amendatory language for the table in the Code of Federal Regulations (CFR). This minor 

editorial correction to the table moves methods from the “Other” column to the “ASTM” 

column, as it applies to the inorganic chemical sampling and analytical requirements. The 

UCMR program is not affected by these changes.

DATES: This final rule is effective on [INSERT DATE 30 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. For purposes of judicial review, this rule 

is promulgated as of 1 p.m. eastern time on [INSERT DATE OF PUBLICATION IN THE 

FEDERAL REGISTER] as provided in 40 CFR 23.7. The incorporation by reference of certain 

publications listed in this rule is approved by the Director of the Federal Register as of [INSERT 

DATE 30 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

ADDRESSES: EPA has established a docket for this action under Docket ID No. EPA-HQ-OW2009-0090. All documents in the docket are listed in the index at www.regulations.gov. 
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Although listed in the index, some information is not publicly available, e.g., confidential 

business information (CBI) or other information, the disclosure of which is restricted by statute. 

Certain other material, such as copyrighted material, is not placed on the Internet and will be 

publicly available only in hard copy form. Publicly available docket materials are available either 

electronically at www.regulations.gov or in hard copy at the Water Docket, EPA/DC, EPA West, 

Room 3334, 1301 Constitution Ave., NW, Washington, DC. This Public Reading Room is open 

from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone 

number for this Public Reading Room is (202) 566-1744, and the telephone number for the 

Water Docket is (202) 566-2426. 

FOR FURTHER INFORMATION CONTACT: Brenda D. Parris, Technical Support Center, 

Standards and Risk Management Division, Office of Ground Water and Drinking Water, United 

States Environmental Protection Agency, Office of Water, 26 West Martin Luther King Drive 

(MS 140), Cincinnati, Ohio 45268; telephone (513) 569-7961; or email at 

parris.brenda@epa.gov. For general information, contact the Safe Drinking Water Hotline. 

Callers within the United States may reach the Hotline at (800) 426-4791. The Hotline is open 

Monday through Friday, excluding legal holidays, from 10:00 a.m. to 4:00 p.m., Eastern time. 

The Safe Drinking Water Hotline may also be found on the Internet at 

http://water.epa.gov/drink/contact.cfm. 

SUPPLEMENTARY INFORMATION:

I. General Information 
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A. Does This Action Apply to Me?

Entities regulated by this action are public water systems (PWSs). All large community 

and non-transient non-community water systems serving more than 10,000 people are required to 

monitor. A community water system (CWS) means a PWS, which has at least 15 service 

connections used by year-round residents or regularly serves an average of at least 25 year-round 

residents. A non-transient non-community water system (NTNCWS) means a PWS that is not a 

CWS and regularly serves at least 25 of the same people over six months per year. Only a 

nationally representative sample of “small” community and non-transient non-community 

systems serving 10,000 or fewer people are required to monitor for the chemical analytes (see 

USEPA, 2001 for a description of the statistical approach for the nationally representative 

sample). EPA will pay for the analysis of samples collected by these small systems. Transient 

non-community water systems (TNCWS) (i.e., systems that do not regularly serve at least 25 of 

the same people over six months per year) are not required to monitor for the chemical analytes. 

However, transient ground water systems serving 1,000 or fewer people may be selected for 

virus monitoring. If selected, these systems are required to permit EPA to sample and analyze for 

List 3 contaminants and pathogen indicators. EPA will pay for all sampling and analysis costs 

associated with virus monitoring at these small systems. Exhibit 1 summarizes UCMR 3 

applicability by system type and size.

Exhibit 1: Applicability of UCMR 3 to Water Utilities by System Type and Size 

UCMR 3 Assessment Monitoring

System Type System Size1

Serving > 10,000 Serving ≤ 10,000
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CWS & 

NTNCWS

Requires all systems to monitor for List 

1 chemicals

Requires 800 randomly selected 

systems to monitor for List 1 

chemicals. EPA will pay for the 

analysis of samples.

TNCWS No requirements No Requirements

UCMR 3 Pre-Screen Testing

System Type System Size1

Serving > 1,000 Serving ≤1,000

CWS, TNCWS 

& NTNCWS No requirements 

Requires 800 randomly selected 

systems to permit EPA to sample and 

analyze List 3 microbes. The selected 

systems will be served by nondisinfecting ground water wells in 

vulnerable areas. EPA will pay for 

the analysis of samples.

1. Based on the retail population, as indicated by SDWIS/Fed on December 31, 2010. 

States, Territories, and Tribes with primary enforcement responsibility (primacy) to 

administer the regulatory program for PWSs under SDWA may participate in the implementation 

of UCMR 3 through Partnership Agreements (PAs). These primacy agencies may choose to

perform the required analysis of samples collected for UCMR 3; however, the PWS remains 

responsible for compliance with this rule. Regulated categories and entities are identified in the 

following exhibit. 

Category Examples of potentially regulated entities NAICSa

State, Local, & Tribal 

Governments 

States, local and Tribal governments that analyze water 

samples on behalf of public water systems required to 

conduct such analysis; States, local and Tribal 

governments that directly operate community, transient 

and non-transient non-community water systems 

required to monitor. 

924110 

Industry Private operators of community and non-transient noncommunity water systems required to monitor. 221310
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Municipalities Municipal operators of community and non-transient 

non-community water systems required to monitor. 924110 a NAICS = North American Industry Classification System

This exhibit is not exhaustive, but rather provides a guide for readers regarding entities 

that may be regulated by this action. This exhibit lists the types of entities that EPA is now aware 

may potentially be regulated by this action. Other types of entities not listed in the exhibit could 

also be regulated. To determine whether your facility is regulated by this action, you should 

carefully examine the definition of PWS in §141.2 of Title 40 of the Code of Federal

Regulations, and applicability criteria in §141.40(a)(1) and (2) of this action. If you have 

questions regarding the applicability of this action to a particular entity, consult the persons listed 

in the preceding FOR FURTHER INFORMATION CONTACT Section. 

B. Copies of This Document and Other Related Information 

This document is available for download at: www.regulations.gov. For other related 

information, see preceding discussion on docket. 

Abbreviations and Acronyms 

μg/L Microgram(s) per Liter

ASDWA Association of State Drinking Water Administrators

AGI Acute Gastrointestinal Illness

CCL Contaminant Candidate List 

CFR Code of Federal Regulations 
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CWS Community Water System

DQO Data Quality Objectives

DSMRT Distribution System Maximum Residence Time

EO Executive Order

ELISA Enzyme-linked Immunosorbent Assay 

EPA United States Environmental Protection Agency 

EPTDS Entry Point to the Distribution System

FR Federal Register

GC/MS Gas Chromatography/Mass Spectrometry

GWUDI Ground Water Under the Direct Influence of Surface Water

HCFC-22 Chlorodifluoromethane 

HPLC/MS/MS High-Performance Liquid Chromatography/Tandem Mass 

Spectrometry

HRL Health Reference Level

IC/MS Ion Chromatography/Mass Spectrometry 

ICR Information Collection Request 

IDC Initial Demonstration of Capability

IHS Indian Health Service

LCMRL Lowest Concentration Minimum Reporting Level 

LC/MS/MS Liquid Chromatography/Tandem Mass Spectrometry

LFSM Laboratory Fortified Sample Matrix

LFSMD Laboratory Fortified Sample Matrix Duplicate
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MDL Method Detection Limit

MRL Minimum Reporting Level

NAICS North American Industry Classification System

NCOD National Drinking Water Contaminant Occurrence Database

ND Not Detected

NTNCWS Non-Transient Non-Community Water System

NTTAA National Technology Transfer and Advancement Act 

NWQL National Water Quality Laboratory

OMB Office of Management and Budget

PA Partnership Agreement

PFBS Perfluorobutanesulfonic Acid

PFC Perfluorinated Compounds 

PFHpA Perfluoroheptanoic Acid

PFHxS Perfluorohexanesulfonic Acid 

PFNA Perfluorononanoic Acid

PFOA Perfluorooctanoic Acid

PFOS Perfluorooctanesulfonic Acid

PT Proficiency Testing

PWS Public Water System

qPCR Quantitative Polymerase Chain Reaction

RFA Regulatory Flexibility Act

SDWARS Safe Drinking Water Accession and Review System
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SM Standard Methods 

SRF State Revolving Fund

SBA Small Business Administration

SDWA Safe Drinking Water Act

SDWIS/Fed Federal Safe Drinking Water Information System

TNCWS Transient Non-Community Water System

TTHM Total Trihalomethanes

UCMR Unregulated Contaminant Monitoring Regulation 

UMRA Unfunded Mandates Reform Act of 1995 

VOC Volatile Organic Compound 

TABLE OF CONTENTS:

I. General Information

A. Does This Action Apply to Me?

B. Copies of This Document and Other Related Information

II. Statutory Authority and Background

A. What is the statutory authority for UCMR?

B. How does EPA meet these statutory requirements?

III. Summary of This Rule

A. What are the major changes between the proposed and final UCMR 3 rule?

B. Which water systems must monitor

1. Applicability Based on Population Served
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2. Applicability for Transient Systems

C. Where are samples collected?

1. Entry point to the distribution system

2. Distribution system maximum residence time location

D. What are the UCMR 3 contaminants and associated methods?

1. List compilation

2. Hormones and related methods

3. Metals, chlorate, and related methods

4. Chromium-6 and total chromium, and related methods

5. Viruses and related methods

E. How are laboratories approved for UCMR 3 monitoring?

1. This rule

2. Summary of major comments

F. How Were Minimum Reporting Levels Determined?

1. This rule

2. Summary of major comments

G. What are the UCMR 3 reporting requirements?

1. General Reporting Requirements/SDWARS

2. Sample location and inventory information (zip codes)

3. Disinfectant Type Specifications

4. Reporting schedule

IV. State and Tribal Participation
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A. Partnership agreements

1. This rule

2. Summary of major comments

B. Governors’ petition and state-wide waivers

1. This rule

2. Summary of major comments

V. Cost and Benefits of This Rule

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: 

Improving Regulation and Regulatory Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act (UMRA)

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments

G. Executive Order 13045: Protection of Children from Environmental Health Risks and 

Safety Risks

H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect 

Energy Supply, Distribution, or Use

I. National Technology Transfer and Advancement Act

J. Executive Order 12898: Federal Actions to Address Environmental Justice in 
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Minority Populations and Low-Income Populations.

K. Congressional Review Act

VII. Public Involvement in Regulation Development

VIII. References

LIST OF EXHIBITS

Exhibit 1: Applicability of UCMR 3 to Water Utilities by System Type and Size

Exhibit 2: UCMR 3 Final Contaminant Lists

Exhibit 3: Timeline of UCMR 3 Activities

Exhibit 4: Changes to UCMR 3 between Proposed and Final Rule

Exhibit 5a: 30 UCMR 3 Analytes and Methods

Exhibit 5b: Total Chromium Monitoring

Exhibit 6: Observed Background Levels During MRL Determination

Exhibit 7: UCMR 3 Per Respondent Burden and Cost Summary for the ICR Period 

(2012-2014)

Exhibit 8: Number of Publicly- and Privately-Owned Small Systems Subject to 

UCMR 3

Exhibit 9: EPA and Systems Costs for Implementation of UCMR 3 at Small Systems

Exhibit 10: UCMR 3 Relative Cost Analysis for Small Publicly-Owned Systems 

(2012-2016)

Exhibit 11: UCMR 3 Relative Cost Analysis for Small Privately-Owned Systems 

(2012-2016)
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II. Statutory Authority and Background 

A. What is the statutory authority for UCMR?

Section 1445(a)(2) of SDWA, as amended in 1996, requires that once every five years, 

the United States Environmental Protection Agency (EPA) issue a new list of no more than 30 

unregulated contaminants to be monitored by public water systems (PWSs). It also requires that 

EPA enter the monitoring data into the Agency’s National Drinking Water Contaminant 

Occurrence Database (NCOD). EPA must ensure that only a nationally representative sample of 

PWSs serving 10,000 or fewer people is required to monitor. EPA must also vary the frequency 

and schedule for monitoring based on the number of persons served, the source of supply, and 

the contaminants likely to be found. 

Section 1445(a)(1)(A) of SDWA, as amended in 1996, requires that every person who is 

subject to any SDWA requirements establish and maintain such records, make such reports, 

conduct such monitoring, and provide such information as the Administrator may reasonably 

require by regulation to assist the Administrator in establishing SDWA regulations. Pursuant to 

this authority, EPA is also requiring the monitoring of total chromium under this final rule. 

B. How does EPA meet these statutory requirements?

This final rule fulfills EPA’s obligation under SDWA by identifying 30 contaminants for 

monitoring during the third UCMR, referred to as “UCMR 3.” These contaminants include: 28 

chemicals measured using up to seven analytical methods and/or four equivalent consensus 

organization-developed methods, and two viruses measured using one sample collection and two 

detection methods. EPA has developed the contaminant list (Exhibit 2) and sampling design for 
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UCMR 3 (2012-2016) with input from both stakeholders and an EPA-State working group.

Exhibit 2: UCMR 3 Final Contaminant Lists

List 1, Assessment Monitoring1

17-β-estradiol bromochloromethane (Halon 1011)

17-α-ethynylestradiol (ethinyl estradiol) 1,4-dioxane

estriol vanadium 

equilin molybdenum 

estrone cobalt

testosterone strontium

4-androstene-3,17-dione chromium-6 (hexavalent chromium)2

1,2,3-trichloropropane chlorate

1,3-butadiene perfluorooctanesulfonic acid (PFOS) 

chloromethane (methyl chloride) perfluorooctanoic acid (PFOA)

1,1-dichloroethane perfluorononanoic acid (PFNA) 

n-propylbenzene perfluorohexanesulfonic acid (PFHxS) 

bromomethane (methyl bromide) perfluoroheptanoic acid (PFHpA) 

chlorodifluoromethane (HCFC-22) perfluorobutanesulfonic acid (PFBS)

List 3, Pre-Screen Testing3

enteroviruses noroviruses

1. Monitoring for total chromium – in conjunction with UCMR 3 Assessment Monitoring – is also required. This monitoring is 

required under the authority provided in Section 1445 (a)(1)(A) of SDWA. 

2. Chromium-6 will be measured as soluble chromate (ion). 

3. Monitoring for microbial indicators – in conjunction with UCMR 3 Pre-Screen Testing – is also required. This monitoring 

includes sampling for pathogen indicators (i.e., total coliforms, E.coli, bacteriophage, Enterococci and aerobic spores). It is not 

subject to the stipulation in Section 1445(a)(2)(B)(i) of SDWA that restricts UCMR contaminants to not more than 30. EPA will 

pay for all sampling and analysis costs associated with virus and indicator monitoring at these small systems.

This list is the same as was provided in the March 3, 2011, proposed rule (76 FR 11713, 

(USEPA, 2011a)), with the exception that chromium-6 (hexavalent chromium) has been 
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substituted for sec-butylbenzene. In addition, EPA is requiring total chromium monitoring under 

the authority provided in Section 1445 (a)(1)(A) of SDWA. 

III. Summary of This Rule

Public water systems (PWS) or EPA will conduct sampling and analysis for Assessment 

Monitoring (List 1) and Pre-Screen Testing (List 3) contaminants, as applicable, at each PWS 

subject to this rule during a 12 month period within the 2013 to 2015 timeframe. Preparations 

prior to 2013 include coordination of laboratory approval, selection of representative samples of 

small systems, development of State Monitoring Plans, establishment of monitoring schedules, 

and notification of participating PWSs. Exhibit 3 illustrates the major activities that will take 

place during implementation of UCMR 3. 

Exhibit 3: Timeline of UCMR 3 Activities

2012 2013 2014 2015 2016

After proposed 

rule publication:

Lab approval 

program begins

After 

applicability 

date: EPA/State 

partnership 

agreements and 

State monitoring 

plans developed 

(inc. national 

representative 

sample and List 3 

systems)

After final rule 

publication: 

Assessment Monitoring

List 1 Contaminants + Total Chromium

All systems serving more than 10,000; 

800 systems serving 10,000 or fewer

Complete 

reporting and 

analysis of data

Pre-Screen Testing

List 3 Contaminants + Indicator Organisms

800 non-disinfecting ground water systems in 

vulnerable areas serving 1,000 or fewer
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Inform 

PWSs/establish 

monitoring plans

“Assessment Monitoring” is the largest in scope of the three UCMR monitoring lists or 

tiers. Under UCMR 3 Assessment Monitoring, 28 “List 1” contaminants will be monitored to 

assess national occurrence in drinking water. These are the contaminants for which analytical 

method technologies are well established.

The second tier of UCMR is referred to as “List 2” or “Screening Survey” monitoring. 

List 2 contaminants are those with analytical methods that have generally been more recently 

developed and employ technologies that are not as widely used; therefore laboratory capacity 

may be insufficient to conduct the larger scale Assessment Monitoring. Unlike UCMR 1 (64 FR 

50556, September 17, 1999, (USEPA, 1999b)) and UCMR 2 (72 FR 367 January 4, 2007, 

(USEPA, 2007)), UCMR 3 includes no Screening Survey monitoring. 

“Pre-Screen Testing,” the third tier of UCMR monitoring is generally designed for “List 

3” contaminants with very new or specialized analytical methods. Under UCMR 3, a selected set 

of 800 systems that serve fewer than 1,000 retail customers and that do not disinfect are required 

to assist EPA in sampling their system for two viruses on List 3 and the associated pathogen 

indicators (i.e., total coliforms, E.coli, bacteriophage, Enterococci and aerobic spores). This 

requirement includes community and non-transient, non-community water systems and transient 

systems.
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EPA will pay for the sample kit preparation, sample shipping fees, and analysis costs to 

minimize the impact of the rule on small systems (those serving 10,000 or fewer people). In 

addition, no small system will be required to monitor for both List 1 and List 3 contaminants. 

Large systems (those serving more than 10,000 people) will pay for the cost of shipping and 

laboratory testing for their List 1 analyses. 

The data collected through the UCMR program are being stored in NCOD to facilitate 

analysis and review of contaminant occurrence, guide the conduct of the Contaminant Candidate 

List (CCL) process and support the Administrator in making regulatory decisions for 

contaminants in the interest of protecting public health, as required under SDWA Section 

1412(b)(1). Results of UCMR 1 and 2 monitoring can be viewed by the public at EPA’s UCMR 

website: http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/data.cfm. 

A. What are the major changes between the proposed and final UCMR 3 rule? 

EPA published “Revisions to the Unregulated Contaminant Monitoring Regulation for 

Public Water Systems; Proposed Rule,” on March 3, 2011 (76 FR 11713, (USEPA, 2011a)).

EPA received input from 53 public commenters. After considering the comments, EPA added 

chromium-6 to the list of contaminants to be monitored under UCMR 3 and removed secbutylbenzene. EPA revised or clarified requirements pertaining to UCMR applicability criteria, 

reporting, monitoring and quality control. Exhibit 4 provides a summary of these changes and a 

listing of the corresponding preamble section that provides a more detailed discussion of the 

revisions and related public comments. Sections III.B-G summarize the different aspects of this 

rule and the associated major comments received in response to the proposed rule. EPA has 
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compiled a more detailed document containing all public comments and EPA’s responses 

entitled: “UCMR 3 Public Comments and Responses,” which can be obtained by going to 

http://www.regulations.gov, and searching for Docket ID No. EPA-HQ-OW-2009-0090. 

Exhibit 4: Changes to UCMR 3 between Proposed and Final Rule

Rule Section

Description of Change Corresponding 

Preamble Section Number Title/Description 

141.35 (c)(1) and (d)(1) Data elements

Revise zip code reporting to 

include only the zip codes for all 

customers served, rather than 

those associated with each 

sampling point 

III.G.2 Sample location 

and inventory 

information (zip codes)

141.35(c)(6)(ii) and

141.40(a)(5)(vi) Reporting schedule Change laboratory reporting time 

to 90 days, rather than 60 days

III.G.4 Reporting 

schedule

141.40(a)(2)(i)(A) and 

(a)(2)(ii)(A); and 

141.40(a)(3) Table 1

Analytes to be monitored 

and related specification

Add chromium-6; remove 

requirement to monitor for secbutylbenzene; require total 

chromium monitoring under 

SDWA Section 1445 (a)(1)(A) 

III.D.4 Chromium-6 and 

total chromium, and 

related methods

III.D.1 List compilation

141.35(c)(2) Sample location and 

inventory information

Large systems must provide 

sample location and inventory 

information to EPA by October 1, 

2012

III.G.4 Reporting 

schedule

141.40(a)(3) Table 1, 

footnote c and 141.40 

(a)(4)(i)(C)

Distribution system 

maximum residence time 

(DSMRT) sample location

Revise definition of DSMRT 

sample required for specific List 1 

contaminants

III.C Where are samples 

collected? 

III.D.3 Metals, chlorate, 

and related methods

141.35(c)(5)(i) and

141.40 (a)(4)(i)

General rescheduling 

notification

Large systems may independently 

change List 1 monitoring 

schedule prior to October 1, 2012

III.G.4 Reporting 

schedule

141.35(c)(3) Ground water representative 

sampling locations

Large systems may submit 

representative sampling plan 

proposals or changes to existing 

plans by June 1, 2012

III.C Where are samples 

collected? 

III.G.4 Reporting 

schedule

141.40(a)(3) Table 1 

footnote c Representative intake

Systems that purchase water from 

the same wholesaler may sample 

from a representative intake 

III.C Where are samples 

collected?

B. Which water systems must monitor
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1. Applicability Based on Population Served 

a. This rule 

This rule requires that Assessment Monitoring (for List 1 contaminants) be conducted by 

all large community and non-transient, non-community water systems serving more than 10,000 

people, and a nationally representative sample of 800 small water systems serving 10,000 or 

fewer people (as indicated by Federal Safe Drinking Water Information System (SDWIS/Fed) on 

December 31, 2010). Transient non-community water systems are excluded from Assessment 

Monitoring. In contrast to implementation of UCMR 1 and 2 monitoring, those systems that 

purchase all of their finished water from another system are not excluded from the requirements 

of UCMR 3. All systems serving more than 10,000 retail customers must monitor.

b. Summary of major comments

EPA received six (6) comments concerning UCMR monitoring based on retail population 

served. The commenters all agreed that applicability should be based on retail population, 

although some wanted to exclude those who purchase their water from that applicability. In 

UCMR 1 and 2, systems that purchased 100% of their water were excluded from monitoring, 

making estimates of exposure more difficult because many of these purchasing systems 

represented high-population areas. For UCMR 3, systems that purchase 100% of their water and 

serve greater than 10,000 people are required to monitor. Wholesalers that have a retail 

population of 10,000 or below are only required to monitor if they are selected as part of the 

nationally representative sample of small systems for any list of UCMR contaminants. This 

should greatly improve exposure estimates for UCMR 3 since exposure estimates will be based 

on where the water is consumed rather than where it is sold.

Some commenters also expressed concern that this applicability change could add an 
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estimated 1,250 systems to the list of those that need to monitor and suggested that this would 

represent a substantial increase in burden to the drinking water industry. To mitigate the burden, 

EPA is allowing those systems that purchase water with multiple connections from the same 

wholesaler to select a representative connection for sampling. See Section III.C.1.a for further 

discussion. 

2. Applicability for Transient Systems 

a. This rule 

Under UCMR 1 and 2, transient non-community water systems were specifically 

exempted from monitoring. UCMR 3 now requires participation by transient systems that are

selected for Pre-Screen Testing for List 3 contaminants. Under UCMR 3, EPA is conducting PreScreen Testing for enterovirus and norovirus, as well as related pathogen indicators, at selected 

undisinfected ground water systems that serve 1,000 or fewer customers. EPA is including 

transient systems among the candidate systems – and focusing on viruses at those systems – 

since viruses are acute pathogens and exposure through a one-time ingestion (e.g., at a transient 

system) is of potential health concern. 

Under 141.40(a)(1) and 141.40(a)(2)(ii)(C), if any system (including transient systems) is 

notified by EPA or its State that it has been selected for Pre-Screen Testing, the system must 

permit EPA (at EPA’s expense) to sample and analyze for List 3 contaminants and pathogen 

indicators (i.e., total coliforms, E. coli, bacteriophage, Enterococci and aerobic spores).

b. Summary of major comments

EPA received two comments on including transient non-community systems for List 3 

monitoring. One fully supported their inclusion, and the other expressed concern that EPA would 

not be able to adequately fund the collection and processing of these samples. EPA is confident 
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that it has budgeted sufficient funds to support these activities. As the second commenter noted, 

transient systems represent a substantial number of the systems serving less than 1,000 

customers; therefore, the sampling of these potentially vulnerable systems for these acute 

pathogens is considered important. 

C. Where are samples collected?

1. Entry point to the distribution system

a. This rule 

As was the case under UCMR 2, UCMR 3 samples will be collected at entry points to the 

distribution system (EPTDSs). PWSs may perform sampling at representative sampling locations 

in two cases:

• Demonstrating Representative Ground Water Sampling Locations: Under this rule, large 

systems that use ground water sources and have multiple EPTDSs can, with prior 

approval, conduct monitoring at representative sampling locations rather than at each 

EPTDS. To monitor at representative EPTDSs, large systems must meet the criteria 

specified in §141.35(c)(3) and receive approval from EPA or the State. Changes to the 

rule language clarify that when identifying a representative well, the well must be 

representative of the highest producing (based on annual volume) and most consistently 

active wells. In addition, the representative well must be in use at the scheduled sampling 

time. An alternative location must be sampled if the representative EPTDS is not 

available at the time of scheduled sampling. This rule establishes a deadline of June 1, 

2012 for submission of new proposals or updates to existing plans. See Section III.G.4
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for further discussion. 

• Representative Intakes from Wholesaler: As specified in §141.40(a)(3) Table 1, footnote 

c, systems that purchase water with multiple connections from the same wholesaler may

select one representative connection from that wholesaler for UCMR sampling. If a PWS 

chooses to select a representative intake, each representative intake must receive water 

from the same source. Additionally, if a PWS chooses to select a representative intake, it 

must choose a sampling location that represents the highest volume EPTDS connection 

and is in use at the time of schedule sampling. If the connection initially selected as the 

representative EPTDS is not available at the time of scheduled sampling, an alternate 

representative connection must be sampled. 

b. Summary of major comments

Five commenters expressed support for EPA’s proposal regarding representative 

sampling points, and representative intakes for PWSs with multiple connections from the same 

wholesaler; commenters cited cost savings as a benefit of this approach. One commenter also 

suggested that EPA’s approach to representative sampling locations should provide additional 

flexibility in cases where multiple water systems are receiving water from the same wholesale

provider. EPA acknowledges that there are many unique situations with the purchase and sale of 

drinking water at the wholesale level. In this final rule, EPA has provided clarifying language in 

§141.40(a)(3) Table 1, footnote c, specifying that a PWS may select a representative intake from 

a given wholesaler. EPA is available to advise PWSs regarding choosing the most appropriate 

sampling site, based on their purchasing situation. 
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2. Distribution system maximum residence time location 

a. This rule 

This rule requires systems that participate in Assessment Monitoring also sample for total 

chromium, chromium-6, cobalt, molybdenum, strontium, vanadium, and chlorate both at 

EPTDSs and in the distribution system. This rule requires systems to collect the samples for 

these analytes at their distribution system maximum residence time (DSMRT) location(s), 

(§§141.40(a)(3) Table 1, footnote c and 141.40(a)(4)(i)(C)). For clarity, EPA deleted the UCMR 

reference to the DSMRT specifications under the Stage 1 disinfection byproducts rule at 

§141.132(b)(1)(i). EPA now defines DSMRT under UCMR as an active point (i.e., a location 

that currently provides water to customers) in the distribution system where the water has been in 

the system the longest relative to the EPTDS. Systems that are subject to the Stage 2 Disinfection 

By-Products Rule should use their total trihalomethanes ((TTHM) highest concentration 

sampling site(s) as their DSMRT sampling site(s) (USEPA, 2003). 

b. Summary of major comments

As described in greater detail in Section III.D.3., “metals, chlorate, and related methods,” 

several commenters suggested that EPA had provided insufficient rationale for requiring 

DSMRT sampling for cobalt, molybdenum, strontium, vanadium, and chlorate. As elements that 

may occur in water both naturally, or through industrial activities, cobalt, molybdenum, 

strontium, and vanadium are expected to be commonly-detected in drinking water. EPA believes 

these metals may be incorporated into pipe deposits and subsequent erosion and/or dissolution 

may result in water-borne concentrations that differ between the DSMRT and the EPTDS. 

Regarding chlorate, the use of disinfectants, including use of hypochlorite, chloramines, chlorine 

dioxide, and ozone can result in chlorate formation. The presence of residual disinfectant in the 
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distribution system and chlorine boosters within the distribution system may result in increases 

in chlorate concentrations at the DSMRT relative to the EPTDS.

D. What are the UCMR 3 contaminants and associated methods?

1. List compilation

a. This rule 

EPA is maintaining the list of contaminants and methods proposed for monitoring with 

the exception of substituting chromium-6 for sec-butylbenzene (see Exhibit 5a). EPA is also 

requiring PWSs to monitor for total chromium concurrently with all chromium-6 monitoring 

(Exhibit 5b). The additional data generated by side-by-side measurements of chromium-6 and 

total chromium will provide valuable information on relative occurrence and the utility of 

monitoring for total chromium as a surrogate for chromium-6.

Exhibit 5a: 30 UCMR 3 Analytes and Methods

7 Hormones using EPA Method 539 (LC/MS/MS)1:

17-β-estradiol estrone

17-α-ethynylestradiol (ethinyl estradiol) testosterone

estriol (16-α-hydroxy-17-β-estradiol) 4-androstene-3,17-dione

equilin

8 Volatile Organic Compounds (VOC) using EPA Method 524.3 (GC/MS)2:

1,2,3-trichloropropane bromomethane (methyl bromide)

1,3-butadiene n-propylbenzene

chloromethane (methyl chloride) chlorodifluoromethane (HCFC-22)

1,1-dichloroethane bromochloromethane (Halon 1011)

Synthetic Organic Compound using EPA Method 522 (GC/MS)3:

1,4-dioxane

4 Metals using EPA Method 200.8 (IC/MS)4 or alternate SM5 or ASTM Methods6:
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cobalt strontium

molybdenum vanadium

Oxyhalide Anion using EPA Method 300.1 (IC/Conductivity)7 or alternate SM8 or ASTM Methods9:

chlorate

6 Perfluorinated Chemicals using EPA Method 537 (LC/MS/MS)10:

perfluorooctanesulfonic acid (PFOS) perfluorohexanesulfonic acid (PFHxS)

perfluorooctanoic acid (PFOA) perfluoroheptanoic acid (PFHpA)

perfluorononanoic acid (PFNA) perfluorobutanesulfonic acid (PFBS)

Chromium-6 using EPA Method 218.7 (IC/Conductivity)11: 

chromium-6

2 Viruses (see Section III.D.5 for methods discussion):12

enterovirus norovirus 

Exhibit 5b: Total Chromium Monitoring

Total Chromium using EPA Method 200.8 (IC/MS)4 or alternate SM5 or ASTM Methods6:

total chromium

1. EPA Method 539 (LC/MS/MS) (USEPA, 2010e)

2. EPA Method 524.3 (GC/MS) (USEPA, 2009a)

3. EPA Method 522 (GC/MS) (USEPA, 2008)

4. EPA Method 200.8 (ICP/MS) (USEPA, 1994)

5. SM 3125 (SM, 21st Ed.,2005) 

6. ASTM D5673-10 (ASTM, 2010)

7. EPA Method 300.1 (IC/Conductivity) (USEPA, 1997)

8. SM 4110D (SM, 21st Ed.,2005)

9. ASTM D6581-08 (ASTM, 2008)

10. EPA Method 537 (LC/MS/MS) (USEPA, 2009b)

11 EPA Method 218.7 (IC/Conductivity) (USEPA, 2011b) 

12. Monitoring also includes sampling for pathogen indicators 

(i.e., total coliforms, E.coli, bacteriophage, Enterococci and 

aerobic spores). EPA will pay for all sampling and analysis costs 

associated with monitoring at these small systems.

b. Summary of major comments

Commenters who expressed an opinion about the proposed UCMR 3 analytes were 

generally supportive. Several commenters suggested that cyanobacterial toxins be added to the 

list of analytes. EPA agrees that cyanobacterial toxins are of significant interest for future 

drinking water monitoring. However, EPA currently does not have an available drinking water 

method for analysis of cyanobacterial toxins. While enzyme-linked immunosorbent assays 

(ELISA) and high-performance liquid chromatography with UV detection (HPLC/UV) methods 

have been published (Howard and Boyer, 2007), they do not provide the level of specificity 

needed for UCMR monitoring. The high-performance liquid chromatography/tandem mass 
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spectrometry (HPLC/MS/MS) methods for cyanobacterial toxins that have been published 

(Oehrle et al., 2010), do not provide suitable accuracy and precision. EPA has conducted and 

will continue to conduct methods development research for cyanobacterial toxins both in-house 

and in cooperation with other laboratories. 

2. Hormones and related methods 

a. This rule 

EPA is finalizing the requirement for monitoring of the hormones as proposed: 17-βestradiol; 17-α-ethynylestradiol; estriol; equilin; estrone; testosterone; and, 4-androstene-3,17-

dione. 

b. Summary of major comments

Two major issues concerning the hormones were raised by commenters. The first was a 

concern that other than 17-α-ethynylestradiol, the hormones all occur naturally. Based on the low 

minimum reporting levels (MRLs) specified in this rule, these commenters were concerned that 

there may be issues with false positives due to background levels of these compounds from 

samplers. 

The ranges of blank results observed during the determination of MRLs are contained in 

Exhibit 6. In all cases the laboratories easily met the requirement that the concentration of the 

analytes observed in the blank must be less than one-third of the MRL. In the “worst case” the 

observed blank level equaled one-eighth the MRL. EPA is requiring the collection of field blank 

samples for UCMR 3 and, to minimize the potential issue of field blank and sample 

contamination, will provide instructions to both the samplers and the laboratory personnel to 

wear nitrile gloves when collecting or handling samples for the hormones. These details are 
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specified in EPA’s technical manual titled: “UCMR 3 Laboratory Approval Requirements and 

Information Document” (USEPA, 2012d). 

Exhibit 6: Observed Background Levels During MRL Determination

Analyte UCMR MRL

(μg/L)

Laboratory 1

(μg/L)

Laboratory 2

(μg/L)

Laboratory 3

(μg/L)

17-β-estradiol 0.0004 ND – 0.00006 ND ND – 0.00005

17-α-ethynylestradiol 0.0009 ND – 0.00007 ND – 0.00008 ND – 0.0002

estriol 0.0008 ND – 0.00007 ND ND – 0.00006

equilin 0.004 ND – 0.00002 ND ND – 0.0005

estrone 0.002 ND – 0.0001 0.00001 – 0.00003 0.02 – 0.0002

testosterone 0.0001 ND ND ND – 0.00001

4-androstene-3,17-dione 0.0003 ND ND ND – 0.000008

ND = Not Detected

EPA also stipulated in the rule that it will evaluate the situation after six months of 

monitoring. If at that time, the data indicate that excessive resampling is occurring, EPA will 

establish alternative MRLs and will notify all affected PWSs and laboratories. 

The second issue concerned whether all of the proposed hormones should be monitored 

(versus a subset of them). There was no consensus among the commenters as to what the 

“subset” should be. Some commenters suggested that monitoring be limited to the five (5) 

proposed hormones that are also listed on the final CCL 3 (17-β-estradiol, 17-α-ethynylestradiol, 

estriol, equilin and estrone). EPA believes that monitoring for testosterone and 4-androstene3,17-dione is also justified. A number of articles have been published that show the occurrence 

of testosterone and 4-androstene-3,17-dione in surface waters:

• National Surface Water Reconnaissance (1999 – 2000): detects of testosterone in 2 

(2.8%) of 70 samples at a median concentration of 0.116 μg/L and a maximum 

concentration of 0.214 μg/L (Kolpin et al., 2002). 
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• California, Rivers, Irrigation Canals, and Tile Drains (2003 – 2005): detects of 

testosterone in 2 (18%) of 11 river samples at a maximum concentration of 0.0006 μg/L; 

detects in 4 (27%) of 15 irrigation canal samples at a maximum concentration of 0.0019 

μg/L; detects in 2 (33%) of 6 tile drain samples at a maximum concentration of <0.0003 

μg/L (Kolodziej et al., 2004). 

• California Surface Waters (2005 – 2006): detects of 4-androstene-3,17-dione in 16 (18%) 

of 89 grazing rangeland surface water samples at a maximum concentration of 0.044 

μg/L (Kolodziej and Sedlak, 2007). 

In addition, testosterone and 4-androstene-3,17-dione have been shown to be relatively 

resistant to oxidation (Mash et al., 2010). 

3. Metals, chlorate, and related methods 

a. This rule 

This rule requires that samples for the metals – chromium-6, total chromium, cobalt, 

molybdenum, strontium, and vanadium – as well as chlorate, be collected at one distribution 

system sampling point per treatment plant (i.e., at the DSMRT) in addition to sampling at the 

EPTDS. DSMRT samples must be collected at a location that represents the maximum residence 

time in the distribution system (§§141.40(a)(3) Table 1, footnote c and 141.40(a)(4)(i)(C)). (As 

noted in Section III.C.2.a of this preamble, EPA clarified the DSMRT specifications and deleted 

the direct DSMRT reference under the Stage 1 disinfection byproducts rule at §141.132(b)(1)(i).) 

EPA is requiring that chlorate samples be collected at both the EPTDS and DSMRT 

locations to permit the Agency to evaluate if chlorate occurs as an oxyhalide disinfection by-
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product 

b. Summary of major comments

Eight commenters suggested that further justification was needed to support monitoring 

cobalt, molybdenum, strontium, and vanadium at the DSMRT. Three commenters also made 

similar comments regarding chlorate. Research indicates that vanadium can become incorporated 

in the corrosion products in iron pipes used for drinking water distribution. As a result, vanadium 

may be released via dissolution and/or erosion of the mineral deposits that form inside many iron 

distribution pipes. Gerke et al. (2010) cite research that indicates that relatively minor scouring 

of these deposits can result in water concentrations of vanadium in excess of 15 μg/L. Similar 

findings were published by the Water Research Foundation (Friedman et al., 2009). The authors 

reported vanadium in scaling from several different distribution systems.

Molybdenum has been identified as being among the heavy metals that can be mobilized 

from reservoir sediments containing iron and aluminum oxides and hydroxides. Fluctuations in 

pH of approximately 0.2 pH units were sufficient to considerably affect the release of previously 

absorbed molybdenum (Friedman et al., 2009). 

Although such findings for cobalt and strontium are not available in the scientific 

literature, these two elements commonly occur in drinking water. As a result, EPA believes that 

incorporation of cobalt and/or strontium into pipe deposits within a distribution system could 

result in mobilization of these metals into drinking water within the distribution system via 

dissolution and/or erosion. Strontium has been found in greatest amounts in calcium-rich 

minerals and sediments due to similarities in atomic radii (Fairbridge, 1972). In addition, 

Friedman et al. (2009) report calcium to be the fourth most concentrated element found in pipe 
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deposit samples. Thus, erosion and/or dissolution of pipe deposits within the distribution system 

may affect human exposure levels for cobalt, molybdenum, strontium, and vanadium. 

The presence of residual disinfectant in the distribution system may result in increases in 

chlorate concentrations at the DSMRT relative to the EPTDS. The following studies on chlorate 

formation have linked its presence in treated drinking water to the use of several disinfection 

processes:

• the generation of chlorine dioxide from chlorite and free chlorine (Gordon et al., 1990; 

Bolyard et al., 1993; Gallagher et al., 1994); 

• the generation of chlorine dioxide from chlorite and hypochlorite (Gallagher et al., 1994); 

• chlorine dioxide oxidation by residual free chlorine (Gordon and Tachiyashiki, 1991; 

Bolyard et al., 1993); 

• transition metal-catalyzed free chlorine decomposition during disinfection (Gordon et al., 

1995); 

• base-catalyzed disproportionation of chlorine dioxide (USEPA, 1999a; Gallagher et al., 

1994); 

• photodecomposition of chlorine dioxide (Rice and Gomez-Taylor, 1986; Bolyard et al., 

1993; Gallagher et al., 1994; Bergmann and Koparal, 2005); 

• use of chlorate-contaminated hypochlorite solutions – chlorate can come from either the 

impurity of the original stock solution or decomposition during storage (Bolyard et al., 

1992; Bolyard et al., 1993; Gordon et al., 1993; Gordon et al., 1995; Gordon et al., 1997; 

USEPA, 1999a; WHO, 2005; Snyder et al., 2009; Stanford et al., 2011);
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• use of ozone with residual chlorine (Siddiqui, 1996; von Gunten, 2003); and 

• use of electrochemical disinfection processes (Czarnetzki and Janssen, 1992; Bergmann 

and Koparal, 2005). 

4. Chromium-6 and total chromium, and related methods 

a. This rule 

While EPA did not include chromium-6 in the proposed list of chemicals for UCMR 3 

monitoring, EPA did request comment on whether the Agency should include it in the final rule

due to the concerns about its potential occurrence in public water supplies. EPA also requested

comments on whether total chromium should be measured concurrent with chromium-6. 

Commenters strongly supported requiring monitoring for both chromium-6 and total chromium. 

EPA agrees with these commenters and has substituted chromium-6 for sec-butylbenzene 

in UCMR 3. EPA also completed the development and validation of a revised analytical method 

for the determination of chromium-6 in drinking water, EPA Method 218.7: Determination of 

Dissolved Hexavalent Chromium in Drinking Water by Ion Chromatography. This revised

method has been extensively studied both within EPA and ion chromatography manufacturers’ 

laboratories as well as through external laboratory validation (USEPA, 2011b). 

EPA is using the authority provided in SDWA Section 1445(a)(1)(A) to require 

monitoring for total chromium in conjunction with the UCMR 3 monitoring of chromium-6. 

b. Summary of major comments

EPA received 30 comments regarding the inclusion of chromium-6 in UCMR 3. Twentyeight of the 30 commenters supported inclusion. The other two suggested that a health risk from 
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drinking water exposure had not been conclusively established, that regional levels of total 

chromium in drinking water are very low, and that speciation would not be beneficial. The 

Agency believes that the ongoing studies of chromium-6 toxicity warrant UCMR monitoring at 

this time. EPA believes that collecting national occurrence data will provide beneficial 

information to the Agency regarding how best to protect human health. EPA’s second Six-Year 

Review of National Primary Drinking Water Regulations s (USEPA, 2010d) indicated that the 

levels of total chromium warrant further investigation of chromium-6 occurrence. Chromium can 

enter the environment from both natural and industrial sources; thus the distribution of both total 

chromium and chromium-6 may vary based on regional geology and regional industrial activity. 

Part of the goal of UCMR is to assess the national distribution of the contaminants selected. 

Commenters who supported the inclusion of chromium-6 cited two primary reasons for 

its inclusion in UCMR 3: 

• generating national occurrence data in UCMR 3 will avoid potential delays in any 

possible regulatory action; 

• monitoring for both total chromium and chromium-6 may allow for determining a 

relationship between the two species, allowing for possible use of total chromium 

monitoring, which is less costly and has better holding time requirements, as a surrogate 

for chromium-6 monitoring. 

While generally supporting chromium-6 monitoring in UCMR 3, some commenters 

expressed concern about the current analytical method. The concerns included procedural issues 

(e.g., field filtration, preservation and holding time compliance), interferences concerns (e.g., 

sensitivity and species interconversion prior to sample analysis), the need for round-robin testing 
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of the method laboratory capacity, and the need to determine a lowest concentration minimum 

reporting level (LCMRL) and MRL for chromium-6. Extensive research by EPA, with support 

from instrument manufacturers and commercial laboratories, addressed the issues of 

interferences, sensitivity and analyte preservation. EPA Method 218.7 has undergone peer 

review, and multi-laboratory LCMRL and MRL determinations have been completed (USEPA, 

2011b; USEPA, 2006). 

Because UCMR is limited by statute to 30 unregulated contaminants, commenters offered 

a variety of suggestions for which analyte to remove to accommodate chromium-6. Suggestions 

included dropping one of the metals, hormones, PFCs, or VOCs. Other suggestions included 

removing “the contaminant with the least chance of being detected during monitoring.” EPA 

selected sec-butylbenzene, a non-carcinogenic VOC, for removal after considering data 

submitted by states that indicated a very low and declining occurrence rate. EPA also considered 

the fact that the currently available health reference level, 10.3 μg/L, is well above the reported

levels of occurrence in these data (USEPA, 2012c). 

5. Viruses and related methods 

a. This rule 

EPA is finalizing the requirement for monitoring of the viruses as proposed. This rule 

requires monitoring for enterovirus and norovirus in UCMR 3 via Pre-Screen Testing of selected

undisinfected ground water systems located in karst or fractured bedrock. The monitoring will

include 800 PWSs serving 1,000 or fewer customers, including CWSs, and non-transient and 

transient non-community water systems. Monitoring will also include sampling for pathogen 

indicators (i.e., total coliforms, E.coli, bacteriophage, Enterococci and aerobic spores). This 
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monitoring will obtain information concerning the occurrence of enterovirus and norovirus for 

further evaluation, and provide EPA with a better understanding of the co-occurrence of 

pathogen indicators and viruses. 

Enteroviruses will be monitored using one method that has two detection assays. The first 

is a cell culture assay also used in the Information Collection Rule survey conducted by EPA (61 

FR 24353, May 14, 1996 (USEPA, 1996)), with one change; the Virosorb 1-MDS filter will be 

replaced by the NanoCeram® filter, which will significantly reduce sampling cost. The 

NanoCeram® filter has proven to be as effective as Virosorb 1- MDS filter for the recovery of 

enteroviruses (Karim et al., 2009) and noroviruses (Gibbons et al., 2010). The second assay is 

quantitative polymerase chain reaction (qPCR) based, and detects the viral nucleic acid. 

Noroviruses will only be monitored using qPCR, as there is no cell culture method available. 

Both norovirus and enterovirus qPCR will be performed per the protocol in Lambertini et 

al. (2008). The qPCR primers and probe for genogroup I norovirus will be as referenced in 

Jothikumar et al. (2005), while genogroup II Norovirus primers and probe will be as referenced 

in Ando et al. (1995). Primers and probe referenced in De Leon et al. (1990) and Monpoeho et al. 

(2000) will be used for enterovirus qPCR.

b. Summary of major comments

Several commenters expressed concern about using Method 1615 for monitoring viruses 

because it has not undergone multi-laboratory validation. EPA notes, however, that individual 

elements of the method have been used by many researchers worldwide, and the culture assay is, 

with the exception of a new filter, identical to the Information Collection Rule validated method 

(FR 24353, May 14, 1996 (USEPA, 1996)). The complete method is published and has 
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undergone thorough peer review as per protocols established by EPA’s National Exposure 

Research Laboratory and consistent with “The Handbook for Preparing ORD Reports” (USEPA, 

1995). The method has undergone validation at EPA’s laboratory, has built in quality controls for 

PCR inhibition, and has positive and negative controls to identify false negative and positive 

assays. Results from the analysis of initial and ongoing positive and negative proficiency testing 

(PT) samples will ensure the ability of analysts to perform the method. 

Several commenters questioned EPA’s use of Borchardt’s (2008) data as the basis for 

including viruses in UCMR 3, since that work has not been published or undergone peer review. 

In his study, Borchardt sampled wells from 14 communities in Wisconsin for the presence of 

enteroviruses and noroviruses. The initial enteric virus RT-qPCR assay results are published in a 

peer reviewed journal (Hunt et. al, 2010). Borchardt’s work showed a statistically significant 

correlation between viral qPCR and self-reported AGI (acute gastrointestinal illness) in the 

population served. Borchardt’s work is also one of the very few studies to assess presence of 

enteric viruses in undisinfected ground water systems. EPA expects that complete results from 

Borchardt’s work will be published in a peer reviewed journal in the near future. The study 

results have also been presented at numerous scientific conferences as well as in testimony to the 

Wisconsin State Senate. A project advisory committee comprised of epidemiologists from the 

University of California, Berkeley, Michigan State University and the University of Washington 

provided additional peer review comments during the study planning and data analysis stages. 

A few commenters expressed concerns as to whether a survey of 800 undisinfected 

ground water systems in a sensitive hydrogeology would be nationally representative, noting that 

only specific geologic regions within the country would be included in the survey. While EPA 
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acknowledges that the 800 undisinfected ground water systems are only a small subset of the 

total number of systems in the country, the selection of 800 PWSs was statistically derived to be 

nationally representative of those with sensitive hydrogeology. 

EPA also received comments regarding how the Agency would use data obtained from a 

focused and limited occurrence survey, at highly vulnerable and susceptible systems, to provide 

meaningful data to judge nationwide occurrence and to support regulatory determination. EPA 

notes that results will provide an understanding of the exposure risks in populations potentially 

served by a large number of undisinfected systems in karst aquifers nationally. Lastly, some 

comments addressed the current information on virus-indicator correlation, suggesting that the 

correlations are weak. EPA notes that most virus-indicator correlation studies have been 

performed in disinfected systems, not undisinfected ground water systems. EPA also notes that 

the use of multiple indicators in looking at the correlation will make this monitoring more useful. 

E. How are laboratories approved for UCMR 3 monitoring? 

1. This rule

All laboratories conducting analyses for UCMR 3 List 1 contaminants must receive EPA

approval to perform those analyses. Laboratories seeking approval are required to provide EPA 

with data that demonstrate their successful completion of an initial demonstration of capability 

(IDC) as outlined in each method, verify successful method performance at the MRLs as 

specified in this action, and successfully participate in an EPA PT program for the analytes of 

interest. On-site audits of candidate laboratories may be conducted. Details of the EPA 

laboratory approval program are contained in the technical manual titled: “UCMR 3 Laboratory 

Approval Requirements and Information Document” (USEPA, 2012d). This document will be 
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available on the electronic docket at www.regulations.gov and will be provided to laboratories 

that register for the laboratory approval program. In addition, EPA may supply analytical 

reference standards of known concentrations for select analytes to participating/approved 

laboratories, where such standards are not readily available through commercial sources. 

Pre-Screen Testing (List 3) analyses for viruses and related pathogen indicators (i.e., total 

coliforms, E. coli, bacteriophage, Enterococci, and aerobic spores) are organized and paid for by 

EPA through direct contracts with microbial laboratories. These laboratories are not required to 

go through the same formal laboratory approval process as the Assessment Monitoring 

laboratories; however, they are subject to an analogous laboratory approval process as part of 

their direct contracts with EPA.

a. Laboratory Approval Process for UCMR 3 

The UCMR 3 laboratory approval program is similar to the approval program under 

UCMR 1 and 2. It is designed to assess and confirm the capability of laboratories to perform 

analyses using the methods listed in §141.40(a)(3), Table 1, of this final rule. It will assess 

whether laboratories meet the required equipment, laboratory performance, and data reporting 

criteria described in this action. This evaluation program is voluntary in that it only applies to 

laboratories intending to analyze UCMR 3 samples. However, EPA requires water systems to 

use UCMR 3 approved laboratories when conducting monitoring for those analytes listed in 

Table 1 of §141.40(a)(3) of this final rule. A list of laboratories approved for UCMR 3 

monitoring is posted to EPA’s UCMR website: 

http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/ucmr3/laboratories.cfm. Laboratories are 

encouraged to apply for UCMR 3 approvals as early as possible, as schedules for large PWS 
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sampling will be completed soon after the final rule is promulgated. The steps for the laboratory 

approval process are listed in the following paragraphs, b through f.

b. Request to participate

Laboratories must contact EPA and request to participate in the UCMR 3 laboratory 

approval program. Laboratories must send their request to: UCMR 3 Laboratory Approval 

Coordinator, USEPA, Technical Support Center, 26 West Martin Luther King Drive (MS 140), 

Cincinnati, OH 45268; or email at: UCMR_Sampling_Coordinator@epa.gov. EPA began 

accepting requests for registration for the List 1 (Assessment Monitoring) methods on March 03, 

2011. The final opportunity for a laboratory to request the necessary registration forms is

[INSERT DATE 90 DAYS AFTER PUBLICATION OF THE FINAL RULE]. 

c. Registration

Each laboratory that wishes to participate in UCMR 3 monitoring must complete a 

registration form. Registration information includes the following: laboratory name, mailing 

address, shipping address, contact name, phone number, email address, and a list of the UCMR 3 

methods for which the laboratory is seeking approval. The registration step provides EPA with 

the necessary contact information, and ensures that each laboratory receives a customized 

application package of materials and instructions for the methods that it plans to use. 

d. Application package

When EPA receives the registration information, a customized application package will 

be emailed to the laboratory for completion. Information requested in the application includes the 

following: IDC data, including precision, accuracy and results of MRL studies; information 

regarding analytical equipment; proof of current drinking water laboratory certification (for any 
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currently regulated chemical); and example chromatograms for each method under review. 

The laboratory must post UCMR 3 monitoring results (on behalf of its PWS clients) to 

EPA’s UCMR electronic data reporting system as a condition of maintaining EPA approval. 

e. EPA review of application package

EPA will review the application package and, if necessary, request follow-up 

information. The laboratory must satisfactorily complete this portion of the process before they 

can participate in the UCMR 3 PT program. 

f. Proficiency testing (PT)

A PT sample is a synthetic sample containing a concentration of an analyte that is known 

to EPA, but unknown to the laboratory being tested. To complete the initial laboratory approval 

process, a laboratory must meet specific acceptance criteria for the analysis of a UCMR 3 PT 

sample(s) for each method for which the laboratory is seeking approval. Initial laboratory 

approval is contingent upon successful completion of a PT study. EPA will offer two to four 

opportunities for a laboratory to successfully analyze UCMR 3 PT samples. At least one of these 

studies will be conducted prior to the publication of the final rule; at least one study will be 

conducted after publication of the final rule. This will allow laboratories to complete their 

portion of the laboratory approval process prior to publication of the final rule, and therefore 

receive their approval immediately following the publication of the final rule, or to wait until the 

final rule is published before completing the required laboratory approval analyses. A laboratory 

must pass one of the PT studies for each analytical method for which they are requesting 

approval. Laboratories applying for UCMR 3 approval and laboratories conducting UCMR 3 

analyses, may be subject to on-site laboratory audits. No PT studies will be conducted after the 
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start of monitoring; however, laboratory audits will be ongoing throughout the entire monitoring 

period of 2013-2015. Continued laboratory approval is contingent upon successful participation 

in any audits conducted by EPA. 

g. Written EPA approval 

After laboratories successfully complete steps “b” through “f” of the laboratory approval 

process, EPA will send the laboratory a letter listing (a) the method(s) for which approval is 

pending (if the PT study and laboratory evaluation are conducted prior to promulgation of the 

final rule) or (b) approval is granted (after promulgation of the final rule). Laboratories receiving 

a pending approval letter (prior to final rule promulgation) will be considered approved without 

further action, following promulgation of the final rule. 

2. Summary of major comments

Three commenters suggested that EPA modify the requirements for PT samples in 

UCMR 3 by including a round of PT samples during the UCMR 3 monitoring period in addition 

to the initial round of PT samples conducted prior to monitoring. Instead of requiring 

laboratories to conduct ongoing PT samples, EPA will conduct ongoing laboratory audits similar

to the process under UCMR 2. Ongoing laboratory audits will allow EPA to evaluate each 

laboratory’s analytical processes for all aspects of sample receipt, storage, processing, analysis 

and reporting of routine samples. This will provide a better mechanism, compared to an 

additional PT study, for uncovering any potential data issues and ensuring that laboratories meet 

the quality requirements. 

F. How Were Minimum Reporting Levels Determined?
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1. This rule

Lowest Concentration Minimum Reporting Levels (LCMRLs) and Minimum Reporting 

Levels (MRLs) for each analyte were determined through an EPA LCMRL study assessing the 

data from multiple laboratories prior to publication of the UCMR 3 proposal. The LCMRL is 

defined as the lowest spiking concentration at which recovery of between 50 and 150% is 

expected 99% of the time by a single analyst.

The LCMRL is estimated using advanced statistical procedures that have been 

incorporated into an LCMRL calculator tool that is available on EPA’s website

(http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm). The tool 

estimates a probability distribution for spike recovery as a function of spiking concentration. 

MRL

EPA revised the definition of the MRL used in UCMR 2 (72 FR 367, January 4, 2007, 

(USEPA, 2007)). The revised definition reflects improvements in the statistical procedures for 

determining the LCMRL and MRL. These improvements were implemented by EPA to make the 

models more robust, i.e., so that the models can accommodate a wider range of observed 

LCMRL data sets (USEPA, 2010f). The MRL for an analyte measured by a specified analytical 

method is designed to be an estimate of an LCMRL that is achievable, with 95% confidence, by 

a capable analyst/laboratory at least 75% of the time. Such a demonstration of ability to reliably 

make quality measurements at the MRL is intended to achieve high quality measurements across 

the nation’s laboratories.

In UCMR 3, EPA estimated the MRL for an analyte/method by obtaining data from 

several laboratories performing corresponding LCMRL studies. These data were used to 

construct an approximation to the distribution that would result from picking at random a 
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laboratory/analyst proficient in performing the analytical method and having them perform an 

LCMRL study and compute an LCMRL estimate. The strategy for computing the MRL is twofold. First, for each LCMRL data set, a distribution for repeated LCMRL determinations by the 

same laboratory/analyst is estimated by generating a large number of simulated values. Second,

these values are combined to create an estimated overall distribution. If a result from one of the 

laboratories is significantly higher than that of other laboratories, this value would be downweighted using a robust weight function. The resulting weighted values are used to construct a 

probability distribution from which the MRL is computed as the 95th percentile. 

2. Summary of major comments 

Several commenters remarked on the complexity of the procedures for determining the 

LCMRL and the MRL. These commenters were concerned about the amount of time and effort 

needed to calculate LCMRLs and MRLs. Some suggested that as an alternative, EPA use the 

procedure developed for consideration by the Clean Water Act as part of the Federal Advisory 

Committee on Detection and Quantitation. As a point of clarification, EPA notes that 

laboratories that participate in UCMR 3 do not need to use the LCMRL and MRL procedures. 

Instead, laboratories that participate in UCMR 3 will be required to demonstrate their ability to 

meet the already-established UCMR 3 analyte MRLs by analyzing reagent water samples spiked 

at or below the established UCMR 3 MRLs. This initial demonstration of capability (IDC) 

requirement, as described in EPA’s “UCMR 3 Laboratory Approval Requirements and 

Information Document,” is no more complex than determining a Method Detection Limit (MDL)

(USEPA, 2012d). 

A diverse selection of laboratories representing different sizes, experience and business 

status were selected to participate in the EPA LCMRL studies (as described previously in this 
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section). For transparency, EPA will provide summary tables showing all LCMRL results for 

UCMR 3 in the docket (USEPA, 2012a).

With regard to comments that the MRLs are being set well below health reference levels 

(HRLs) in certain cases, EPA believes that this is appropriate because new health effects data 

may become available in the future that result in lower HRLs. 

G. What are the UCMR 3 reporting requirements?

1. General Reporting Requirements/SDWARS

a. This rule

Under this rule, EPA is committed to pre-populating the inventory and monitoring data in 

the reporting system (Safe Drinking Water Accession and Review System (SDWARS)), using 

data from UCMR 2 and SDWIS/Fed information. For PWSs subject to UCMR 3 that have data 

in SDWARS from UCMR 2, EPA will transfer data to “SDWARS 3” (i.e., the SDWARS update 

associated with UCMR 3). For water systems that are new to UCMR, EPA will pull the available 

information from SDWIS/Fed and coordinate with States and EPA Regions for their input where 

possible. EPA will load the available information into SDWARS 3 prior to the publication of this 

final rule. PWSs will then have until October 1, 2012, to update, edit, or change their information 

or monitoring schedule in SDWARS 3 (see Section III.G.4 for further discussion of reporting 

deadlines). 

b. Summary of major comments

Several commenters expressed concern over possible inefficiencies related to data entry 

into SDWARS, including concern over duplication of past efforts (e.g., having to re-enter 
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information for each sample point for each sampling event) and time spent identifying 

representative sampling locations at both the EPTDS and DSMRT for UCMR 2. Commenters 

further noted it would be very helpful if elements that are duplicated for each sample would be 

automatically pre-filled in each field once the information was entered the first time. As noted, 

for UCMR 3, EPA plans to preload as much inventory to SDWARS as possible and is taking 

commenter suggestions into consideration in its design updates to SDWARS. The pre-loaded 

data will include representative sampling locations previously identified at the EPTDS and 

DSMRT. PWSs will be asked to verify their inventory in SDWARS and large systems may be 

required to revise this information once their ground water representative monitoring plan has 

been approved, depending on the level of their State’s involvement. See Section III.G.4 for 

discussion of reporting deadlines. 

2. Sample location and inventory information (zip codes)

a. This rule 

This final rule establishes a requirement for reporting zip codes associated with all PWS 

customers. EPA had proposed reporting of sampling point U.S. Postal Service Zip Codes and the 

zip codes of all customers served by a given sampling point (as part of the reporting associated 

with Data Element 4 – Sampling Point Identification Code). Obtaining the zip code of the 

sampling point was intended to assist with future vulnerability assessments. Zip codes that tie 

populations served to each sampling point were intended to assist with future occurrence and 

exposure analyses. However, based on stakeholder concerns about the burden associated with 

reporting this information and concerns about the usefulness of having the zip code of the 

sampling point, EPA revised the rule language to establish a requirement of only reporting zip 

codes for customers served by the PWS. These reporting specifications are now established in 
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§§141.35(c)(1) and (d)(1) for large and small systems, respectively. EPA believes that required 

reporting of customer zip codes will provide EPA with useful information for future occurrence 

analyses.

b. Summary of major comments

Eight comments were received regarding the proposed zip code reporting requirements. 

Most commenters believed that reporting the zip code for each sampling point location would 

not provide EPA with the information necessary to make future correlations between water 

quality and the areas served by the water being distributed. After considering public comments, 

EPA has revised the reporting requirement to only include the zip codes served by the PWS. 

3. Disinfectant Type Specifications

a. This rule 

EPA is changing Data Element 6, in Table 1 of 141.35(e). Under UCMR 2, this data 

element was established to provide information on “Disinfectant Residual Type” as it related to 

monitoring for nitrosamines (part of UCMR 2 Screening Survey monitoring). EPA is modifying 

the definition of this data element to account for changes to the analyte and monitoring 

specifications between UCMR 2 and UCMR 3. This revised definition lists additional 

disinfectant types to provide more specific information on the sources and types of disinfectant 

schemes that may lead to chlorate formation/occurrence in drinking water. 

b. Summary of major comments

While commenters were supportive of the collection of these data, several commenters 

noted that the requirement for reporting this data element was unclear. Some commenters noted 
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that PWSs frequently use multiple disinfectants and reporting only one of those would provide 

an inaccurate assessment of disinfectants being used. Others noted that EPA needed to make sure 

that PWSs indicate whether their hypochlorite solution was generated on or off site (onsite: 

essentially no storage of stock solution will be needed; offsite: the storage of stock solution will 

be needed). 

EPA agrees that the presentation of the requirements warranted clarification and has 

revised the list of disinfectants. EPA will clearly indicate in the data reporting system 

(SDWARS) that PWSs should identify all of the disinfectants used to treat the water. 

4. Reporting schedule

a. This rule 

To help ensure that monitoring and reporting are conducted as scheduled, UCMR 3 

specifies several deadlines related to initial reporting of inventory and scheduling information, as 

well as reporting of monitoring data. Several deadlines were newly proposed for UCMR 3 (i.e., 

not used for UCMR 1 or UCMR 2) and finalized in this rule, and some are revised in this final 

rule to ensure that UCMR 3 is implemented as scheduled. These deadlines are being established 

to allow EPA enough time to review and process the information, and complete the planning 

process for UCMR 3 monitoring to begin on January 1, 2013. Changes in deadlines only affect 

large systems. There are no changes to small system reporting schedules. The schedule changes 

that are finalized in this rule include: 

• Inventory and Scheduling: Large systems that are subject to UCMR 3 must report their 

inventory and sampling location information (141.35(c)(2)), and any proposed changes to 

their monitoring schedule (141.35(c)(5)(i) and 141.40(a)(4)(i)) no later than October 1, 
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2012. As noted, EPA will load existing information into SDWARS 3 prior to the 

publication of this final rule. PWSs will have until October 1, 2012 to update, edit, or 

change their inventory and sample location information or monitoring schedule in 

SDWARS 3. 

• Ground water representative monitoring plans: As described in 141.35(c)(3), large 

systems that use ground water sources and that have multiple EPTDSs can, with prior 

approval, conduct monitoring at representative sampling locations rather than at each 

EPTDS. For systems that have existing approved representative monitoring plans, their 

approved sampling location information will be pre-loaded into SDWARS and systems 

must review and confirm, or update this information by October 1, 2012. This rule 

establishes a deadline of June 1, 2012 for submitting a new ground water representative 

plan to be reviewed by the State or EPA. 

• Monitoring data: This rule establishes two revised deadlines related to reporting of 

monitoring data: large systems must require their laboratories to post data to SDWARS

within 90 days of sample collection; and large systems must review, approve, and submit 

the data to their State and EPA within 30 days of when the laboratory posts the data. 

These time frames are specified in 141.35(c)(6)(ii) and 141.40(a)(5)(vi). 

b. Summary of major comments

Five comments were received on the reduced laboratory reporting timeframe. Most 

commenters did not support the 60-day proposed timeframe for laboratories to post data to 

SDWARS and expressed several concerns: that laboratories may see increased workload due to 

additional monitoring; that UCMR 3 methods are not in common use and are very sensitive, so 
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greater validation of results may be required; and that field blank analysis may be required for 

some methods, resulting in longer turnaround times for sampling results. Commenters did not 

believe that the reduced reporting timeframe would increase compliance with monitoring 

schedules. Seven comments were also received regarding the 30-day proposed timeframe for 

large PWSs to review and approve their data. The majority of the commenters requested the 

timeframe be returned to the 60-day period used under UCMR 1 and 2. Commenters believe the 

shortened timeframe would not give PWSs sufficient time to conduct a full data review and that 

schedule coordination among multiple staff would be difficult. After considering the public 

comments, EPA has increased the laboratory reporting timeframe to 90 days after sample 

collection and retained the PWS reporting timeframe of 30 days after laboratory posting data. 

EPA believes that these turn-around-times are feasible given historical information from 

UCMR 2 on laboratory reporting and system approval of data: 

• Laboratory posting of data to SDWARS: 90% of the data posted by laboratories were 

posted within 92 days of sample collection. 

• PWS approval of laboratory data: 65% of PWSs chose to explicitly approve their data, as 

opposed to allowing automatic approval by SDWARS 60 days after laboratory posting of 

data; of PWSs that explicitly approved their data, 90% did so within 35 days of the 

laboratory posting data. 

IV. State and Tribal Participation 

A. Partnership agreements

1. This rule
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Under UCMR 3, States may continue to have a role in rule implementation through 

Partnership Agreements (PAs). Because specific activities for individual States are identified and 

established through the PAs, not through rule language, this rule does not contain reference to 

PAs.

2. Summary of major comments 

EPA received no comments regarding State participation in UCMR 3. 

B. Governors’ petition and state-wide waivers

1. This rule

This rule retains the UCMR 1 and 2 language that, consistent with SDWA, allows a 

minimum of seven State Governors to petition EPA to add contaminants to the UCMR 

Contaminant list. This rule also retains the UCMR 1 and 2 language that allows States to waive 

monitoring requirements with EPA approval and under very limited conditions. 

2. Summary of major comments 

EPA received no comments regarding the governor’s petition or state-wide waiver 

allowances of UCMR 3. 

V. Cost and Benefits of This Rule

In this rule, EPA finalizes a new set of contaminants for monitoring in the third five-year 

UCMR monitoring period. UCMR 3 also incorporates modifications to improve the rule design. 

UCMR 3 Assessment Monitoring (for List 1 contaminants) will be conducted from January 2013 

through December 2015 by 800 systems serving 10,000 or fewer people, and by all systems 

serving more than 10,000 people. The 800 small systems will be randomly selected for List 1 
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monitoring. The Pre-Screen Testing for List 3 contaminants will also be conducted from January 

2013 through December 2015 in 800 undisinfected ground water systems serving 1,000 or fewer 

persons (different systems than those selected for List 1 monitoring). 

It is assumed for this cost estimate that one-third of systems will monitor during each of 

the three monitoring years. Labor costs pertain to systems, States, and EPA. They include 

activities such as reading the regulation, notifying systems selected to participate, training water 

system staff on sample collection procedures, sample collection, including travel time to collect 

samples, data review, reporting, and record keeping. Non-labor costs will be incurred primarily 

by EPA and by large PWSs. They include the cost of shipping samples to laboratories for testing 

and the cost of the actual laboratory analyses.

In this rule, EPA specifies seven EPA-developed analytical methods and four equivalent 

consensus organization developed methods to monitor for 28 UCMR 3 chemical contaminants, 

and two viruses for a total of 30 contaminants. While this preamble also describes the analytical 

methods that will be used for virus monitoring, the rule does not address these methods. 

Laboratory approval for virus monitoring is not addressed since all of the analyses for the two 

viruses will be conducted in laboratories under EPA contract and at EPA’s expense. Estimated 

system and EPA costs are based on the analytical costs for all UCMR 3 methods. With the 

exception of Methods 200.8 and 300.1, these methods are comparatively new and will not 

coincide with other compliance monitoring (i.e., no cost savings for concurrent monitoring can 

be realized). 

Laboratory analysis and shipping of samples account for approximately 89% of the total 

national cost for UCMR 3 implementation. These costs are calculated as follows: the number of 
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systems, multiplied by the number of sampling locations, multiplied by the sampling frequency, 

multiplied by the unit cost of laboratory analysis. Under UCMR 3, for List 1 Assessment 

Monitoring, surface water (and ground water under the direct influence of surface water

(GWUDI)) sampling points will be monitored four times during the applicable year of 

monitoring, and ground water sample points will be monitored twice during the applicable year 

of monitoring. Systems will monitor for the metals – cobalt, molybdenum, vanadium, strontium, 

chromium-6, and total chromium – as well as chlorate, at their EPTDS sampling locations and at 

one distribution system sampling point per treatment plant (i.e., at the DSMRT). Pre-Screen 

Testing systems will monitor two times during the three year monitoring period (2013 through 

2015) at their EPTDS. 

Following publication of the proposed rule and EPA’s initial cost and burden estimates, 

EPA received several cost-related public comments. Several suggested that EPA’s estimates of 

cost and burden (e.g., laboratory and estimated labor burden) to PWSs were too low. 

EPA estimates of laboratory fees are based on consultations with commercial drinking 

water laboratories and a review of the costs of similar analytical methods. In response to 

comments, EPA revisited the analytical method cost estimates. EPA approached four 

commercial drinking water laboratories and requested pricing estimates for UCMR 3 methods, 

including the cost of field blanks for methods 524.3 (VOCs), 537 (PFCs), and 539 (hormones). 

EPA averaged the estimates from the four laboratories and updated the cost figures. 

With respect to per-system burden estimates, EPA notes that all estimates represent 

average burden hours, which include surface water systems that may have very few sampling 

points, and thus lower sampling burden, as well as those systems with higher numbers of 
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sampling points that would have greater labor burden. Moreover, a system’s burden is primarily 

incurred during its one year of required UCMR monitoring (between January 2013 and 

December 2015). However, in compliance with the requirements of the Paperwork Reduction 

Act (44 U.S.C. 3501 et seq.), these cost and burden estimates are presented as an average over 

the applicable three-year information collection request (ICR) period (2012 - 2014). Small 

systems (those serving 10,000 or fewer people) will have the lowest burden not only because 

they generally have fewer sampling locations, but also because these systems will receive 

substantial direct assistance from EPA and/or their State. 

The cost of the Assessment Monitoring analysis for the UCMR 3 chemicals is estimated 

at $1,503 per sample set (at the EPTDS) where contaminants are not detected, and field blank 

samples for methods 524.3 (VOCs), 537 (PFCs), and 539 (hormones) do not have to be 

analyzed. The cost to analyze both a UCMR sample and a field blank sample (where 

contaminants are detected) for the three methods above is estimated at $2,300. The cost to EPA 

of the Pre-Screen analyses for viruses and related pathogen indicators (i.e., total coliforms, E. 

coli, bacteriophage, Enterococci, and aerobic spores) is estimated at $1,880 per sample set. 

Shipping estimates are added to the calculated costs to derive the total direct analytical non-labor 

costs. Estimated shipping costs were based on the average cost of shipping a 25-pound package. 

In preparing the UCMR 3 ICR, EPA relied on standard assumptions and data sources 

used in the preparation of other drinking water program ICRs. These include the PWS inventory, 

number of sampling points per system, and labor rates. EPA expects that States will incur only 

labor costs associated with voluntary assistance with UCMR 3 implementation. State costs were 

estimated using the relevant modules of the State Resource Model that was developed by the 
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Association of State Drinking Water Administrators (ASDWA) in conjunction with EPA 

(ASDWA, 2003) to help States forecast resource needs. Model estimates were adjusted to 

account for actual levels of State participation under UCMR. Because State participation is 

voluntary, level of effort will vary across States and depend on their individual agreements with 

EPA.

Over the UCMR implementation period of 2012-2016, EPA estimates that nationwide, 

the average annual cost of UCMR 3 is approximately $19.8 million. These total estimated annual 

costs (labor and non-labor) are incurred as follows:

Respondent Avg. Annual Cost. All 

Respondents (2012-16)

Small Systems (25-10,000), including labor only, non-labor costs paid for by EPA $0.052 m

Large Systems (10,001-100,000), including labor and non-labor costs $11.8 m

Very Large Systems (100,001 and greater), including labor and non-labor costs $2.9 m

States, including labor costs related to implementation coordination $0.75 m

EPA, including labor for implementation, non-labor for small system testing $4.2 m

AVERAGE ANNUAL NATIONAL TOTAL1 $19.8 m

1. Average Annual National Total of $19.8 million is based on rounding.

Additional details regarding EPA’s cost assumptions and estimates can be found in the 

ICR amendment prepared for this final rule (Office of Management and Budget (OMB) number 

2040-NEW), which presents estimated cost and burden for the 2012-2014 period. Estimates of 

costs over the entire five-year UCMR 3 period of 2012-2016 are attached as an appendix to the 

ICR. Copies of the ICR and its amendment may be obtained from the EPA public docket for this 

final rule under Docket ID Number EPA-HQ-OW-2009-0090. 
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VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 

Order 13563: Improving Regulation and Regulatory Review 

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this action is a 

“significant regulatory action.” Accordingly, EPA submitted this action to the Office of 

Management and Budget (OMB) for review under Executive Orders 12866 and 13563 (76 FR 

3821, January 21, 2011) and any changes made in response to OMB recommendations have been 

documented in the docket for this action. 

In addition, EPA prepared an analysis of the potential costs and benefits associated with 

this action. This analysis is contained in the “Information Collection Request for the Unregulated 

Contaminant Monitoring Regulation (UCMR 3)”. A copy of the analysis is available in the 

docket for this action and the analysis is briefly summarized in Section V of the preamble of this 

final rule.

B. Paperwork Reduction Act

The information collection requirements in this rule have been submitted for approval to 

the Office of Management and Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C. 

3501 et seq. The information collection requirements are not enforceable until OMB approves 

them.

The information collected under this final rule fulfills the statutory requirements of 

Section 1445(a)(2) of SDWA, as amended in 1996. The data collected will describe the source of 

the water, location, and test results for samples taken from PWSs. The concentrations of any 

identified UCMR contaminants will be evaluated in conjunction with health effects information 
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and will be considered for future regulation accordingly. Reporting is mandatory. The data are 

not subject to confidentiality protection. 

The annual burden and cost estimates described in this section are for the implementation 

assumptions described in Section V. Cost and Benefits of the Rule. Respondents to the UCMR 3

will include 1,600 small water systems (800 for Assessment Monitoring, and 800 for Pre-Screen 

Testing), the 4,215 large PWSs, and the 56 States and Primacy agencies (5,871 total 

respondents). The frequency of response varies across respondents and years. System costs 

(particularly laboratory analytical costs) vary depending on the number of sampling locations. 

For cost estimates, it is assumed that systems will conduct sampling evenly across January 2013 

through December 2015 (i.e., one-third of systems in each of the 3 consecutive 12-month 

periods). Because the applicable ICR period is 2012-2014, the third year of monitoring activity 

(i.e., January through December of 2015) is not captured in the current ICR estimates.

The burden and cost estimates presented in this section represent average costs. In some 

cases, the costs are presented as an annual average. Average burden or cost per system was 

derived by calculating total costs, and dividing by the total number of systems expected to 

monitor during the ICR years of 2012-2014. Average annual burden or cost per system was 

derived by summing total costs (or burden), dividing by the number of systems expected to 

monitor during the ICR years of 2012-2014, and then dividing by three years. The total costs and 

the annual average costs over the ICR years of 2012-2014 are presented in Exhibit 7. Total and 

annual average costs for the entire 5-year UCMR 3 period can be found in the ICR for UCMR 3, 

available in the docket for this final rule.

Small systems (those serving 10,000 or fewer) that are selected for UCMR 3 monitoring 
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will sample an average of 2.3 times per system (i.e., number of responses per system) across the 

three-year ICR period of 2012-2014. The average burden per response for small systems is 

estimated to be 3.1 hours. Large systems (those serving 10,001 to 100,000 people) and very large 

systems (those serving more than 100,000 people) will sample and report an average of 2.7 and

3.7 times per system, respectively, across the three-year ICR period of 2012-2014. The average 

burden per response for large and very large systems is estimated to be 9.1 and 9.4 hours, 

respectively. States are assumed to have an average of 1.0 response per year (3.0 responses per 

State across the three-year ICR period of 2012-2014), related to coordination with EPA and 

systems, with an average burden per response of 233 hours. In aggregate, during the ICR period 

of 2012-2014, the average response (e.g., responses from systems and States) is associated with a 

burden of 11.3 hours, with a labor plus non-labor cost of $4,984 per response. Exhibit 7 presents 

respondent burden and cost estimates for the ICR period of 2012-2014. 

Exhibit 7: UCMR 3 Per Respondent Burden and Cost Summary for the ICR Period 

(2012-2014) 

Burden (hours)/

Cost (dollars)

Small 

Systems

Large 

Systems

Very Large 

Systems States National Average

Three-Year Total Per Respondent

Total # of Responses Per 

Respondent (hr) 2.3 2.7 3.7 3.0 2.7

Labor Cost Per Respondent $162 $767 $1,327 $41,975 $1,229

Non-Labor Cost Per Respondent $0 $14,756 $34,181 $0 $11,904

Total Cost (Labor plus Non-Labor) $162 $15,524 $35,508 $41,975 $13,133

Total Cost Per Response $69 $5,781 $9,673 $13,992 $4,927

Total Burden Per Respondent (hr) 7.0 24.6 34.6 700.1 30.1

Total Burden Per Response (hr) 3.0 9.1 9.4 233.4 11.3

Average Annual Per Respondent

Ave. # of Responses Per 

Respondent (hr) 0.8 0.9 1.2 1.0 0.9

Labor Cost Per Respondent $54 $256 $442 $13,992 $410

Non-Labor Cost Per Respondent $0 $4,919 $11,394 $0 $3,968
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Exhibit 7: UCMR 3 Per Respondent Burden and Cost Summary for the ICR Period 

(2012-2014) 

Burden (hours)/

Cost (dollars)

Small 

Systems

Large 

Systems

Very Large 

Systems States National Average

Ave. Cost (Labor plus Non-Labor) $54 $5,175 $11,836 $13,992 $4,378

Ave. Cost Per Response $23 $1,927 $3,224 $4,664 $1,642

Ave. Burden Per Respondent (hr) 2.3 8.2 11.6 233.4 10

Ave. Burden Per Response (hr) 1.0 3.0 3.1 61.3 3.8

The average per respondent burden hours and costs per year for the ICR period of 2012-

2014 are: small systems – 2.3 hour burden at $54 for labor; large systems – 8.2 hours at $256 for 

labor, and $4,919 for analytical costs; very large systems – 11.6 hours at $442 for labor, and 

$11,394 for analytical costs; and States – 233.4 hours at $13,992 for labor. Burden is defined at 5 

CFR 1320.3(b).

An agency may not conduct or sponsor, and a person is not required to respond to, a 

collection of information unless it displays a currently valid OMB control number. The OMB 

control numbers for EPA’s regulations in 40 CFR are listed in 40 CFR part 9. When this ICR is 

approved by OMB, the Agency will publish a technical amendment to 40 CFR part 9 in the 

Federal Register to display the OMB control number for the approved information collection 

requirements contained in this final rule. 

C. Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) generally requires an agency to prepare a 

regulatory flexibility analysis of any rule subject to notice and comment rulemaking 

requirements under the Administrative Procedure Act or any other statute unless the agency 

certifies that the rule will not have a significant economic impact on a substantial number of 
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small entities. Small entities include small businesses, small organizations, and small 

governmental jurisdictions. 

The RFA provides default definitions for each type of small entity. Small entities are 

defined as: (1) a small business as defined by the Small Business Administration’s (SBA) 

regulations at 13 CFR 121.201; (2) a small governmental jurisdiction that is a government of a 

city, county, town, school district or special district with a population of less than 50,000; and (3) 

a small organization that is any “not-for-profit enterprise which is independently owned and 

operated and is not dominant in its field.” However, the RFA also authorizes an agency to use 

alternative definitions for each category of small entity, “which are appropriate to the activities 

of the agency” after proposing the alternative definition(s) in the Federal Register and taking 

comment (5 U.S.C. 601(3) - (5)). In addition, to establish an alternative small business definition, 

agencies must consult with SBA’s Chief Counsel for Advocacy. 

For purposes of assessing the impacts of this rule on small entities, EPA considered small 

entities to be PWSs serving 10,000 or fewer people, because this is the system size specified in 

SDWA as requiring special consideration with respect to small system flexibility. As required by 

the RFA, EPA proposed using this alternative definition in the Federal Register (63 FR 7606, 

February 13, 1998 (USEPA, 1998a)), requested public comment, consulted with the SBA, and 

finalized the alternative definition in the Consumer Confidence Reports rulemaking (63 FR 

44512, August 19, 1998 (USEPA, 1998b)). As stated in that Final Rule, the alternative definition 

will be applied to future drinking water regulations, including this regulation. 

After considering the economic impacts of this rule on small entities, I certify that this 

action will not have a significant economic impact on a substantial number of small entities. The 
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small entities directly regulated by this rule are PWSs serving 10,000 or fewer people. EPA has 

determined that the small entities subject to the requirements of this rule are a subset of the small 

PWSs (those serving 10,000 or fewer people). The Agency has determined that 1,600 small 

PWSs (across Assessment Monitoring and Pre-Screen Testing), or approximately 3% of small

systems, will experience an impact of no more than 0.4% of revenues; the remainder of small 

systems will not be impacted.

Although this final rule will not have a significant economic impact on a substantial 

number of small entities, EPA has tried to reduce the impact of this rule on small entities. To 

ensure that this rule will not have a significant economic impact on a substantial number of small 

entities, EPA will assume all costs for analyses of the samples and for shipping the samples from 

these systems to the laboratories contracted by EPA to analyze UCMR 3 samples. EPA has set 

aside $2.0 million each year from the State Revolving Fund (SRF) with its authority to use SRF 

monies for the purposes of implementing this provision of SDWA. Thus, the costs to these small 

systems will be limited to the labor hours associated with 800 small systems collecting an 

Assessment Monitoring sample and preparing it for shipping. 

The evaluation of the overall impact on small systems, summarized in the preceding 

discussion, is further described as follows. EPA analyzed the impacts for privately-owned and 

publicly-owned water systems separately due to the different economic characteristics of these 

ownership types, such as different rate structures and profit goals. For both publicly- and 

privately-owned systems, EPA used the “revenue test,” which compares annual system costs 

attributed to the rule to the system’s annual revenues. Median revenue data from the 2006 

Community Water System Survey Volume II: Detailed Tables and Survey Methodology 
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(http://water.epa.gov/aboutow/ogwdw/upload/cwssreportvolumeII2006.pdf) were used for public 

and private water systems. EPA assumes that the distribution of the sample of participating small 

systems will reflect the proportions of publicly- and privately-owned systems in the national 

inventory. The estimated distribution of the representative sample, categorized by ownership

type, source water, and system size, is presented in Exhibit 8. 

Exhibit 8: Number of Publicly- and Privately-Owned Small Systems Subject to UCMR 3 

System Size

(# of people served) Publicly-Owned Privately-Owned Total

Ground Water

500 and under 121 364 485

501 to 3,300 451 172 623

3,301 to 10,000 179 41 220

Subtotal GW 751 577 1,328

Surface Water (and GWUDI)

500 and under 5 5 10

501 to 3,300 61 22 83

3,301 to 10,000 139 40 179

Subtotal SW 205 67 272

Total of Small Water Systems 956 644 1,600

The basis for the UCMR 3 RFA certification for this final rule is as follows: for the 1,600 

small water systems that will be affected, the average annual costs for complying with this rule 

represent 0.4% of system revenues (the highest estimated percentage is for ground water systems 

serving 500 or fewer people, at 0.41% of its median revenue). Exhibit 9 presents the yearly costs 
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to small systems and to EPA for the small system sampling program, along with an illustration of 

system participation for each year of the UCMR 3 program. 

Exhibit 9: EPA and Systems Costs for Implementation of UCMR 3 at Small Systems 

Cost 

Description 2012 2013 2014 2015 2016 Total 

Costs to EPA for Small System Program (including Assessment Monitoring, and Pre-Screen 

Testing)

$0 $5,550,429 $5,550,429 $5,550,429 $0 $16,651,288 

Costs to Small Systems (including Assessment Monitoring, and Pre-Screen Testing):

$0 $86,405 $86,405 $86,405 $0 $259,214 

Total Costs to EPA and Small Systems for UCMR 3:

$0 $5,636,834 $5,636,834 $5,636,834 $0 $16,910,502

System Monitoring Activity Timeline:1

Assessment 

Monitoring

1/3 PWSs 

Sample

1/3 PWSs 

Sample

1/3 PWSs 

Sample 800 

Pre-Screen 

Testing

1/3 PWSs 

Sample

1/3 PWSs 

Sample

1/3 PWSs 

Sample 800

1 Total number of systems is 1,600. No small system conducts more than one type of monitoring study.

System costs are attributed to the labor required for reading about their requirements, 

training staff on requirements, monitoring, including travel time needed to collect samples, 

reporting, and record keeping. The estimated average annual burden across the five-year 

UCMR 3 implementation period of 2012-2016 is estimated to be 1.4 hours at $32 per small 

system. Average annual cost, in all cases, is less than or equal to 0.41% of system revenues. As 

required by SDWA, the Agency specifically structured the rule to avoid significantly affecting 
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small entities by assuming all costs for laboratory analyses, shipping, and quality control for 

small entities. As a result, EPA incurs the entirety of the non-labor costs associated with 

UCMR 3 small system monitoring, or 99% of total small system testing costs. Exhibits 10 and 11 

present the estimated economic impacts in the form of a revenue test for publicly- and privatelyowned systems. 

Exhibit 10: UCMR 3 Relative Cost Analysis for Small Publicly-Owned Systems 

(2012-2016) 

System Size

(# of people 

served)

Annual 

Number of 

Systems 

Impacted

Average 

Annual Hours 

per System 

(2012-2016) 

Average 

Annual Cost 

per System 

(2012-2016) 

Revenue Test 1

Ground Water Systems

500 and under 24 1.2 $24.32 0.08%

501 to 3,300 90 1.3 $27.98 0.02%

3,301 to 10,000 36 1.7 $43.71 0.01%

Surface Water (and GWUDI) Systems

500 and under 1 1.8 $38.06 0.07% 

501 to 3,300 12 1.9 $41.99 0.02% 

3,301 to 10,000 28 2.0 $51.02 0.005% 

1 The “Revenue Test” was used to evaluate the economic impact of an information collection on small government 

entities (e.g., publicly-owned systems); costs are presented as a percentage of median annual revenue in each size category.

Exhibit 11: UCMR 3 Relative Cost Analysis for Small Privately-Owned Systems (2012-2016) 

System Size

(# of people 

served)

Annual 

Number of 

Systems 

Impacted

Average 

Annual Hours 

per System 

(2012-2016)

Average 

Annual Cost 

per System 

(2012-2016)

Revenue Test 1
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Ground Water Systems

500 and under 73 1.2 $24.32 0.41%

501 to 3,300 34 1.3 $27.98 0.03% 

3,301 to 10,000 8 1.7 $43.71 0.004%

Surface Water (and GWUDI) Systems

500 and under 1 1.8 $38.06 0.11%

501 to 3,300 4 1.9 $41.99 0.02% 

3,301 to 10,000 8 2.0 $51.02 0.005% 

1 The “Revenue Test” was used to evaluate the economic impact of an information collection on small private entities 

(e.g., privately-owned systems); costs are presented as a percentage of median annual revenue in each size category.

EPA specifically solicited additional comment on the proposed action on small systems. 

No comments were received.

D. Unfunded Mandates Reform Act (UMRA)

This rule does not contain a Federal mandate that may result in expenditures of $100 

million or more for State, local, and tribal governments, in the aggregate, or the private sector in 

any one year. Total annual costs of this final rule (across the implementation period of 2012–

2016), for State, local, and Tribal governments and the private sector, are estimated to be $19.8 

million, of which EPA will pay $4.2 million, or approximately 21%. Thus, this rule is not subject 

to the requirements of Sections 202 or 205 of UMRA. 

This rule is also not subject to the requirements of Section 203 of UMRA because it 

contains no regulatory requirements that might significantly or uniquely affect small 

governments. As noted previously, the Agency expects to pay for the reasonable costs of sample 
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analysis for the small PWSs required to monitor for unregulated contaminants under this final 

rule, including those owned and operated by small governments. The only costs that small 

systems will incur are those attributed to collecting the UCMR samples and packing them for 

shipment to the laboratory (EPA will pay for shipping). These costs are minimal. They are not 

significant or unique. Thus, this rule is not subject to the requirements of UMRA Section 203. 

E. Executive Order 13132: Federalism 

This action does not have federalism implications. It will not have substantial direct 

effects on the States, on the relationship between the national government and the States, or on 

the distribution of power and responsibilities among the various levels of government, as 

specified in Executive Order 13132. The cost to State and local governments is minimal and the 

rule does not preempt State law. Thus, Executive Order 13132 does not apply to this action. In 

the spirit of Executive Order 13132, and consistent with EPA policy to promote communications 

between EPA and State and local governments, EPA specifically solicited comment on the 

proposed action from State and local officials. 

F. Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments

Subject to the Executive Order 13175 (65 FR 67249, November 9, 2000) EPA may not 

issue a regulation that has tribal implications, that imposes substantial direct compliance costs, 

and that is not required by statute, unless the Federal government provides the funds necessary to 

pay the direct compliance costs incurred by tribal governments, or EPA consults with tribal 

officials early in the process of developing the proposed regulation and develops a tribal 
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summary impact statement.

EPA has concluded that this action will have tribal implications. However, it will neither 

impose substantial direct compliance costs on tribal governments, nor preempt Tribal law. As 

described previously, this final rule requires monitoring by all large systems (i.e., those serving 

more than 10,000 people); 17 Tribal water systems have been identified as large systems based 

on information in the SDWIS/Fed water system inventory. EPA estimates the average annual 

cost to each of these large systems, over the five-year rule period, to be less than $3,105. This 

cost is based on a labor component (associated with the collection of samples) and a non-labor 

component (associated with shipping and laboratory fees) and represents less than 0.11% of 

average revenue/sales for large systems. UCMR also requires monitoring by a nationally 

representative sample of small systems (i.e., those serving 10,000 or fewer people). EPA 

estimates that approximately one percent of small Tribal systems will be selected as a nationally 

representative sample for Assessment Monitoring. EPA estimates the average annual cost to the 

small Tribal systems, over the five year rule period to be $32. Such cost is based on the labor 

associated with collecting a sample and preparing it for shipping and represents 0.4% or less of 

average revenue/sales for small systems. All other small-system expenses (associated with 

shipping and laboratory fees) are paid by EPA. 

EPA consulted with tribal officials early in the process of developing UCMR to permit 

them to have meaningful and timely input into its development. In developing the original 

UCMR rule, EPA held stakeholder meetings and prepared background information for 

stakeholder review. EPA sent requests for review of stakeholder documents to nearly 400 Tribes,

Tribal organizations, and small systems organizations to obtain their input. Representatives from 
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the Indian Health Service (IHS) Sanitary Deficiency System and Tribes were consulted regarding 

decisions on rule design, the design for the statistical selection of small systems, and potential 

costs. Tribes raised issues concerning the selection of the nationally representative sample of 

small systems, particularly the manner in which Tribal systems would be considered under the 

sample selection process. EPA developed the sample frame for Tribal systems and Alaska Native 

water systems in response to those concerns. EPA worked with the Tribes, Alaska Natives, the 

IHS, and the States to determine how to classify each Tribal system for consideration in the 

statistically-based selection of the nationally representative sample of small systems. As a result 

of those discussions, small PWSs located in Indian country in each of the EPA Regions 

containing Indian country were evaluated as part of a Tribal category that receives selection 

consideration comparable to that of small systems outside of Indian country. Thus, Tribal 

systems have the same probability of being selected as other water systems in the stratified 

selection process that weighs systems by water source and size class by population served. This 

final rule maintains the basic program design of UCMR 1 and 2, and continues to build upon the 

structure of this cyclical program. As part of the development of this rule, EPA held a public 

stakeholder meeting on April 7, 2010. This meeting was announced to the public in a Federal

Register notice dated February 23, 2010 (75 FR 8063 (USEPA, 2010a)). Prior to the meeting, 

background materials and rule development information were sent to specific stakeholders, 

including representatives from the IHS and the Native American Water Association.

EPA specifically solicited additional comment on the proposed action from tribal 

officials. EPA received no comments.
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G. Executive Order 13045: Protection of Children from Environmental Health 

Risks and Safety Risks

EPA interprets EO 13045 (62 FR 19885, April 23, 1997) as applying only to those 

regulatory actions that concern health or safety risks, such that the analysis required under 

Section 5-501 of the EO has the potential to influence the regulation. This action is not subject to 

EO 13045 because it does not establish an environmental standard intended to mitigate health or 

safety risks and it is not an economically significant regulation pursuant to EO 12866. 

H. Executive Order 13211: Actions Concerning Regulations That Significantly 

Affect Energy Supply, Distribution, or Use 

This action is not a “significant energy action” as defined in Executive Order 13211 (66 

FR 28355 (May 22, 2001)), because it is not likely to have a significant adverse effect on the 

supply, distribution, or use of energy. None of the final UCMR requirements involve actions that 

use a measurable amount of energy. 

I. National Technology Transfer and Advancement Act 

Section 12(d) of the National Technology Transfer and Advancement Act of 1995 

(“NTTAA”), Public Law No. 104-113, 12(d) (15 U.S.C. 272 note) directs EPA to use voluntary 

consensus standards in its regulatory activities unless to do so would be inconsistent with 

applicable law or otherwise impractical. Voluntary consensus standards are technical standards 

(e.g., materials specifications, test methods, sampling procedures, and business practices) that are 

developed or adopted by voluntary consensus standards bodies. NTTAA directs EPA to provide 

Congress, through OMB, explanations when the Agency decides not to use available and 
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applicable voluntary consensus standards. 

This rulemaking involves technical standards. EPA has decided to use the methods 

developed by the Agency as well as voluntary consensus standards for the analysis of UCMR 3 

contaminants. The Agency conducted a search of potentially applicable voluntary consensus 

standards and identified two major organizations whose methods are acceptable for 

determinations under UCMR. These organizations are Standard Methods (SM) and ASTM 

International. For many of the parameters included in this final action, EPA was unable to 

identify methods from voluntary consensus method organizations that were appropriate for the 

monitoring required. However, EPA identified acceptable consensus method organization 

standards for the analysis of total chromium, vanadium, molybdenum, cobalt, strontium and 

chlorate. Therefore, EPA is approving analytical methods published by EPA, SM, and ASTM 

International for these analytes.

J. Executive Order 12898: Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations.

Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes federal executive 

policy on environmental justice. Its main provision directs federal agencies, to the greatest extent 

practicable and permitted by law, to make environmental justice part of their mission by 

identifying and addressing, as appropriate, disproportionately high and adverse human health or 

environmental effects of their programs, policies, and activities on minority populations and lowincome populations in the United States. 

EPA has determined that this final rule will not have disproportionately high and adverse 

human health or environmental effects on minority or low-income populations because it 
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increases the level of environmental protection for all affected populations without having any 

disproportionately high and adverse human health or environmental effects on any population, 

including any minority or low-income population. By seeking to identify unregulated 

contaminants that may pose health risks via drinking water from all PWSs, UCMR furthers the 

protection of public health for all citizens, including minority and low-income populations using 

public water supplies. UCMR uses a statistically-derived set of systems for the nationally 

representative sample that is population-weighted within each system size and source water 

category so that any PWS within a category has an equivalent likelihood of selection. 

Additionally, EPA is requiring that PWSs report all U.S. Postal Service Zip Codes in their 

service area. This additional data element will be used in the evaluation of UCMR 3 occurrence 

data and could potentially identify areas that have disproportionately high and adverse human 

health or environmental effects on minority or low-income populations. 

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business 

Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take 

effect, the agency promulgating the rule must submit a rule report, which includes a copy of the 

rule, to each House of the Congress and to the Comptroller General of the United States. EPA 

will submit a report containing this rule and other required information to the U.S. Senate, the 

U.S. House of Representatives, and the Comptroller General of the United States prior to 

publication of the rule in the Federal Register. A Major rule cannot take effect until 60 days after 

it is published in the Federal Register. This action is not a “major rule” as defined by 5 U.S.C. 
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804(2). This rule will be effective [INSERT DATE 30 DAYS AFTER PUBLICATION IN THE 

FEDERAL REGISTER].

VII. Public Involvement in Regulation Development

EPA’s Office of Ground Water and Drinking Water routinely engages stakeholders in its 

regulatory activities for the purpose of providing early input to regulation development. When 

designing and developing the UCMR program in the late 1990s, EPA held meetings for 

developing the CCL, establishing the information requirements of the NCOD, and selecting 

priority contaminants for UCMR monitoring. During the initial development of the UCMR 

program, stakeholders including PWSs, States, industry, and other organizations attended 

meetings to discuss the UCMR. Seventeen other meetings were held specifically concerning 

UCMR development. For a description of public involvement activities related to the first

UCMR (UCMR 1), please see the discussion in the September 17, 1999 UCMR Final Rule 

Federal Register at 64 FR 50556 (USEPA, 1999b).

Specific to the development of UCMR 3, a stakeholder meeting was held on April 7, 

2010, in Washington, DC. There were 22 attendees, representing State agencies, laboratories, 

PWSs, environmental groups, and drinking water associations. The topics of presentations and 

discussions included: status of UCMR 2; rationale for developing the new list of potential 

contaminants; analytical methods that could be used in measuring these contaminants; sampling 

design; procedure for determining LCMRLs; laboratory approval; and other potential revisions 

based on lessons learned during implementation of UCMR 1 and UCMR 2 (see USEPA, 2010b 

for presentation materials, and USEPA, 2010c for meeting notes). 
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EPA requested public comment on the proposed rule (76 FR 11713, March 3, 2011 

(USEPA, 2011a)), and established a public docket, under Docket ID No. EPA-HQ-OW-2009-

0090. Each set of comments received in response to this request was assigned an EPA Document 

ID (EPA-HQ-OW-2009-0090+unique four digit extension) and posted for public access on 

regulations.gov. To view comments, search for the docket ID on the regulations.gov homepage, 

then click the link to public submissions. 

EPA received feedback on UCMR 3 from 53 commenters. Commenters included: private 

citizens; local and State governments as well as U.S. territories; industry and industry groups; 

drinking water systems and organizations; and, non-governmental organizations, such as 

environmental and health advocacy groups. An overview of key comments received is included 

in Section III of this rule, and the complete report of comments and full EPA responses can be 

found in the docket on regulations.gov (USEPA, 2012b). 

VIII. References

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differentiation of antigenically distinct small round-structured viruses (Norwalk-like 

viruses) by reverse transcription-PCR and southern hybridization. Journal of Clinical 

Microbiology. 33(1):64-71. 

Association of State Drinking Water Administrators (ASDWA). 2003. Public Health Protection 

Threatened by Inadequate Resources for State Drinking Water Programs–An Analysis of 

State Drinking Water Programs Resources, Needs, and Barriers. April 2003. 

ASTM D5673-10. 2010. Standard Test Method for Elements in Water by Inductively Coupled 
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Plasma-Mass Spectrometry. Available for purchase on the Internet at 

http://www.astm.org/Standards/D5673.htm. 

ASTM D6581-08. 2008. Standard Test Methods for Bromate, Bromide, Chlorate, and Chlorite 

in Drinking Water by Suppressed Ion Chromatography. Available for purchase on the 

Internet at http://www.astm.org/Standards/D6581.htm. 

Bergmann, H. and S. Koparal. 2005. The formation of chlorine dioxide in the electrochemical 

treatment of drinking water for disinfection. Electrochimica Acta. 50:5218-5228. 

Bolyard, M., P.S. Fair, and D.P. Hautman. 1992. Occurrence of chlorate in hypochlorite 

solutions used for drinking water disinfection. Environmental Science and Technology.

26(8):1663-1665. 

Bolyard, M., P.S. Fair, and D.P. Hautman. 1993. Sources of chlorate ion in US drinking water.

Journal of the American Water Works Association. 85(9):81-88. 

Borchardt, M.A. 2008. Wisconsin Water And Health Trial for Enteric Risks (WAHTER Study) - 

Part 1:Risk of Illness from Municipal Groundwater Consumption. EPA Office of Water 

Symposium on Groundwater-Borne Infectious Disease, Etiologic Agents and Indicators, 

Washington, DC, December 2-4, 2008. 

Czarnetzki, L.R. and J.J. Janssen. 1992. Formation of hypochlorite, chlorate, and oxygen during 

NaCl electrolysis from alkaline solutions at an RuO2/TiO2 anode. Journal of Applied 

Electrochemistry. 22:315-324. 

De Leon, R., C. Shieh, R.S. Baric, and M.D. Sobsey. 1990. Detection of enteroviruses and 

hepatitis A virus in environmental samples by gene probes and polymerase chain 

reaction. P. 833-835. In Advances of Water Analysis and Treatment Proceedings 1989. 
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Water Quality Technology Conference, American Water Works Association, Denver, 

CO. American Water Works Association, San Diego, CA. 

Fairbridge, R.W. 1972. The Encyclopedia of Geochemistry and Environmental Sciences, IVA 

Volume. New York: Van Nostrand Reinhold Company. 

Friedman, M.J., A.S. Hill, S.H Reiber, R.L. Valentine, and G.V. Korshin. 2009. Assessment of 

Inorganics Accumulation in Drinking Water System Scales and Sediments. Published by 

WRF. 

Gallagher, D.L, R.C Hoehn, and A.M. Dietrich. 1994. Sources, Occurrence, and Control of 

Chlorine Dioxide By-Product Residuals in Drinking Water. Published by AwwaRF and 

AWWA.

Gerke, T.L., K.G. Scheckel, and J.B. Maynard. 2010. Speciation and distribution of vanadium in 

drinking water iron pipe corrosion by-products. Science of the Total Environment. 

408(23):5845-5853. 

Gibbons, C.D., R.A. Rodriguez., L. Tallon, and M.D. Sobsey. 2010. Evaluation of positively 

charged alumina nanofibre cartridge filters for the primary concentration of noroviruses, 

adenoviruses and male-specific coliphages from seawater. Journal of Applied 

Microbiology. 109(2):635-641. 

Gordon, G., B. Slootmaekers, S. Tachiyashiki, and D.W. Wood III. 1990. Minimizing chlorite 

ion and chlorate ion in water treated with chlorine dioxide. Journal of the American 

Water Works Association. 82(4):160-165. 

Gordon, G. and S. Tachiyashiki. 1991. Kinetics and mechanism of formation of chlorate ion 

from the hypochlorous acid/chlorite ion reaction at pH 6-10. Environmental Science and 
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Technology. 25(3):468-474. 

Gordon, G., L.C. Adam, B.P. Bubnis, B. Hoyt, A.J. Gillette, and A. Wilczak. 1993. Controlling 

the formation of chlorate ion in liquid hypochlorite feedstocks. Journal of the American 

Water Works Association. 85(9):89-97. 

Gordon, G., L.C. Adam, and B.P. Bubnis. 1995. Minimizing Chlorate Ion Formation in Drinking 

Water When Hypochlorite Ion is the Chlorinating Agent. Published by AwwaRF and 

AWWA.

Gordon, G., L.C. Adam, B.P. Bubnis, C. Kuo, R.S. Cushing, and R.H. Sakaji. 1997. Predicting 

liquid bleach decomposition. Journal of the American Water Works Association.

89(4):142-149. 

Howard, K.L. and G.L. Boyer. 2007. Quantitative analysis of cyanobacterial toxins by matrixassisted laser desorption ionization mass spectrometry. Analytical Chemistry. 

79(15):5980-5986. 

Hunt, R.J., M.A. Borchardt, K.D. Richards, and S.K. Spencer. 2010. Assessment of sewer source 

contamination of drinking water wells using tracers and human enteric viruses. 

Environmental Science and Technology. 44(20):7956-7963. 

Jothikumar, N., J.A. Lowther, K. Henshilwood, D.N. Lees, V.R. Hill, and J. Vinje ́. 2005. Rapid 

and sensitive detection of noroviruses by using TaqMan-based one-step reverse 

transcription-PCR assays and application to naturally contaminated shellfish samples. 

Applied and Environmental Microbiology. 71(4):1870-1875. 

Karim, M.R., E.R. Rhodes, N. Brinkman, L. Wymer, and G.S. Fout. 2009. New electropositive 

filter for concentrating enteroviruses and noroviruses from large volumes of water. 
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Applied and Environmental Microbiology. 75(8):2393–2399. 

Kolodziej, E.P., T. Harter, and D.L. Sedlak. 2004. Dairy wastewater, aquaculture, and spawning 

fish as sources of steroid hormones in the aquatic environment. Environmental Science 

and Technology. 38:6377-6384. 

Kolodziej, E.P. and D.L. Sedlak. 2007. Rangeland grazing as a source of steroid hormones to 

surface waters. Environmental Science and Technology. 41:3514-3520. 

Kolpin, D.W., E.T. Furlong, M.T. Meyer, E.M. Thurman, S.D. Zaugg, L.B. Barber, and H.T. 

Buxton. 2002. Pharmaceuticals, hormones, and other organic wastewater contaminants in 

U.S. streams, 1999-2000: A national reconnaissance. Environmental Science and 

Technology. 36:1202-1211. 

Lambertini, E., S.K. Spencer, P.D. Bertz, F.J. Loge, B.A. Kieke, and M.A. Borchardt. 2008. 

Concentration of enteroviruses, adenoviruses, and noroviruses from drinking water by 

use of glass wool filters. Applied and Environmental Microbiology. 74(10):2990-2996. 

Mash, H., K. Schenck, and L. Rosenblum. 2010. Hypochlorite oxidation of select androgenic 

steroids. Water Research. 44:1950-1960. 

Monpoeho, S., A. Dehée, B. Mignotte, L. Schwartzbrod, V. Marechal, J.C. Nicolas, S. Billaudel, 

and V. Ferré. 2000. Quantification of enterovirus RNA in sludge samples by single tube 

real-time RT-PCR. BioTechniques. 29:88-95. 

Oehrle, S.A., B. Southwell, and J. Westrick. 2010. Detection of various freshwater 

cyanobacterial toxins using ultra-performance liquid chromatography tandem mass 

spectrometry. Toxicon. 55:965-972. 

Rice, R.G. and M. Gomez-Taylor. 1986. Occurrence of by-products of strong oxidants reacting 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

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with drinking water contaminants-scope of the problem. Environmental Health 

Perspectives. 69:31-44. 

Siddiqui, M.S. 1996. Chlorine-ozone interactions: Formation of chlorate. Water Research.

30(8):2160-2170. 

Snyder, S.A., B.D. Stanford, A.N. Pisarenko, G. Gordon, and M. Asami. 2009. Hypochlorite – 

An Assessment of Factors that Influence the Formation of Perchlorate and Other 

Contaminants. Jointly funded by AWWA and WRF. Available on the Internet at 

http://www.awwa.org/files/GovtPublicAffairs/PDF/HypochloriteAssess.pdf. 

SM 3125. 2005. Metals by Inductively Coupled Plasma/Mass Spectrometry. Standard Methods 

for the Examination of Water and Wastewater, 21st edition. American Public Health 

Association, 800 I Street, NW, Washington, DC 20001-3710. 

SM 4110D. 2005. Determination of Anions by Ion Chromatography, Part D, IC Determination of 

Oxyhalides and Bromide. Standard Methods for the Examination of Water and 

Wastewater, 21st edition. American Public Health Association, 800 I Street, NW, 

Washington, DC 20001-3710. 

Stanford, B.D., A.B. Pisarenko, S.A. Snyder, and G. Gordon. 2011. Perchlorate, bromate, and 

chlorate in hypochlorite solutions: Guidelines for utilities. Journal of the American Water 

Works Association. 103(6):71-83. 

USEPA. 1994. Method 200.8 - Determination of Trace Elements in Waters and Wastes by 

Inductively Coupled Plasma-Mass Spectrometry. Revision 5.4. Available on the Internet 

at https://www.nemi.gov/. 

USEPA. 1995. Handbook for Preparing Office of Research and Development Reports, Third 
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Edition. EPA 600-K-95-002. August 1995. 

USEPA. 1996. National Primary Drinking Water Regulations: Monitoring Requirements for 

Public Drinking Water Supplies: Cryptosporidium, Giardia, Viruses, Disinfection 

Byproducts, Water Treatment Plant Data and Other Information Requirements. Federal 

Register. Vol. 61, No. 94, p. 24353, May 14, 1996. 

USEPA. 1997. Method 300.1 - Determination of Inorganic Anions in Drinking Water by Ion 

Chromatography. Revision 1.0. Available on the Internet at

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

USEPA. 1998a. 40 CFR Parts 141 and 142 National Primary Drinking Water Regulations: 

Consumer Confidence; Proposed Rule. Federal Register. Vol. 63, No. 30, p. 7606, 

February 13, 1998.

USEPA. 1998b. 40 CFR Parts 141 and 142 National Primary Drinking Water Regulation: 

Consumer Confidence Reports; Final Rule. Federal Register. Vol. 63, No. 160, p. 44512, 

August 19, 1998.

USEPA. 1999a. Alternative Disinfectants and Oxidants Guidance Manual. Office of Water. EPA 

815-R-99-014. April 1999. Available on the Internet at 

http://water.epa.gov/lawsregs/rulesregs/sdwa/mdbp/mdbptg.cfm. 

USEPA. 1999b. Revisions to the Unregulated Contaminant Monitoring Regulation for Public 

Water Systems; Final Rule. 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). EPA 815-R-01-004. August 2001. 
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USEPA. 2003. National Primary Drinking Water Regulations: Stage 2 Disinfectants and 

Disinfection Byproducts Rule; National Primary and Secondary Drinking Water 

Regulations: Approval of Analytical Methods for Chemical Contaminants. Federal

Register. Vol. 68, No. 159, p. 49547, August 18, 2003. 

USEPA. 2006. U.S. Environmental Protection Agency Peer Review Handbook, Third Edition. 

EPA 100-B-06-002. Available on the Internet at 

http://www.epa.gov/peerreview/pdfs/peer_review_handbook_2006.pdf. 

USEPA. 2007. Unregulated Contaminant Monitoring Regulation (UCMR) for Public Water 

Systems Revisions. Federal Register. Vol. 72, No. 2, p. 367, January 4, 2007. 

USEPA. 2008. Method 522 - Determination of 1,4-Dioxane in Drinking Water by Solid Phase 

Extraction (SPE) and Gas Chromatography/Mass Spectrometry (GC/MS) with Selected 

Ion Monitoring (SIM). Version 1.0, September 2008. EPA 600-R-08-101. Available on 

the Internet at http://www.epa.gov/nerlcwww/ordmeth.htm. 

USEPA. 2009a. Method 524.3 - Measurement of Purgeable Organic Compounds in Water by 

Capillary Column Gas Chromatography/Mass Spectrometry. Version 1.0, June 2009. 

EPA 815-B-09-009. Available on the Internet at 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

USEPA. 2009b. Method 537 - Determination of Selected Perfluorinated Alkyl Acids in Drinking 

Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass 

Spectrometry (LC/MS/MS). Version 1.1, September 2009. EPA 600-R-08-092. Available 

on the Internet at http://www.epa.gov/nerlcwww/ordmeth.htm. 

USEPA. 2010a. Stakeholder Meeting Regarding Revisions to the Unregulated Contaminant 
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Monitoring Regulation. Federal Register. Vol. 75, No. 35, p. 8063, February 23, 2010. 

USEPA. 2010b. Stakeholder Meeting Regarding Revisions to the Unregulated Contaminant 

Monitoring Regulation – Presentation Materials. April 7, 2010. 

USEPA. 2010c. Stakeholder Meeting Regarding Revisions to the Unregulated Contaminant 

Monitoring Regulation – Meeting Notes. April 2010. 

USEPA. 2010d. The Analysis of Regulated Contaminant Occurrence Data from Public Water 

Systems in Support of the Second Six-Year Review of National Primary Drinking Water 

Regulations. EPA 815-B-09-006. September 2010. Available on the Internet at 

http://water.epa.gov/lawsregs/rulesregs/regulatingcontaminants/sixyearreview/second_re

view/upload/6Yr2OccurrenceReport_Revised_September2010.pdf. 

USEPA. 2010e. Method 539 - Determination of Hormones in Drinking Water by Solid Phase 

Extraction (SPE) and Liquid Chromatography Electrospray Ionization Tandem Mass 

Spectrometry (LC-ESI-MS/MS). Version 1.0, November 2010. EPA 815-B-10-001. 

Available on the Internet at 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

USEPA. 2010f. Technical Basis for the Lowest Concentration Minimum Reporting Level 

(LCMRL) Calculator. EPA 815-R-11-001. December 2010. 

USEPA. 2011a. Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) 

for Public Water Systems; Proposed Rule. Federal Register. Vol. 76, No. 42, p. 11713, 

March 3, 2011. 

USEPA. 2011b. EPA Method 218.7 - Determination of Dissolved Hexavalent Chromium in 

Drinking Water by Ion Chromatography. Version 1.0, November 2011. EPA 600-R-11-
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0XX. Available on the Internet at 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

USEPA. 2012a. Memo to file: Summary of Lowest Concentration Minimum Reporting Level 

(LCMRL) Results for UCMR 3. January 2012. 

USEPA. 2012b. Response to Comments Document for the Unregulated Contaminant Monitoring 

Regulation (UCMR 3).EPA 815-R-11-004. January 2012. 

USEPA. 2012c. UCMR 3 Contaminants – Information Compendium. EPA 815-B-11-001. 

January 2012. 

USEPA. 2012d. UCMR 3 Laboratory Approval Requirements and Information Document. 

Version 2.0. EPA 815-R-11-003. January 2012. 

von Gunten, U. 2003. Ozonation of drinking water: Part II. Disinfection and by-product 

formation in presence of bromide, iodide or chlorine. Water Research. 37:1469-1487. 

World Health Organization (WHO). 2005. Chlorite and Chlorate in Drinking-water, 

Background Document for Development of WHO Guidelines for Drinking-water Quality, 

WHO/SDE/WSH/05.08/86. 

List of Subjects

40 CFR Part 141 

Environmental protection, Chemicals, Incorporation by reference, Indians-lands, 

Intergovernmental relations, Radiation protection, Reporting and record keeping requirements, 

Water supply. 
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[Title: Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for 

Public Water Systems; page 81 of 108] 

40 CFR Part 142 

Environmental protection, Administrative practices and procedures, Chemicals, Indian 

lands, Radiation protection, Reporting and recordkeeping requirements, Water supply. 

Dated: 

Lisa P. Jackson, 

Administrator.

For the reasons set out in the preamble, Title 40, chapter 1 of the Code of Federal

Regulations is amended as follows: 

PART 141 - NATIONAL PRIMARY DRINKING WATER REGULATIONS

1. The authority citation for Part 141 continues to read as follows: 
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Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 

300j-9, and 300j-11. 

Subpart C – Monitoring and Analytical Requirements

2. Section 141.23 is amended in the table to paragraph (k)(1) by revising entries 18, 19, and 20; 

and by removing footnote 23. 

The revisions read as follows: 

§141.23 Inorganic chemical sampling and analytical requirements.

* * * * * 

(k) Inorganic analysis: 

* * * * * 

Contaminant Methodology13 EPA Method ASTM3 SM4 (18th, 

19th ed.)

SM4 (20th

ed.)

SM 

Online22 Other

* * * * * * *

18. Nitrate Ion 

Chromatography

300.06

300.119

D4327-97, 

03

4110 B 4110 B 4110 B00B-10118

Automated 

Cadmium 

Reduction

353.26 D3867-90 

A 

4500-NO3

-

F 

4500-NO3

-

F 

4500-

NO3

-

 F00

Ion Selective 

Electrode

......................... .................. 4500-NO3

-

D 

4500-NO3

-

D 

4500-

NO3

-

 D00

6017

Manual Cadmium 

Reduction 

......................... D3867-90 

B 

4500-NO3

-

E 

4500-NO3

-

E 

4500-

NO3

-

 E00
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Contaminant Methodology13 EPA Method ASTM3 SM4 (18th, 

19th ed.)

SM4 (20th

ed.)

SM 

Online22 Other

Capillary Ion 

Electrophoresis

......................... D6508-00. ................. ................. ..............

19. Nitrite Ion 

Chromatography 

300.06

300.119

D4327-97, 

03 

4110 B.... 4110 B.... 4110 B00 B-10118

Automated 

Cadmium 

Reduction 

353.26 D3867-90 

A 

4500-NO3

-

F 

4500-NO3

-

F 

4500-

NO3

-

 F00 

Manual Cadmium 

Reduction 

......................... D3867-90 

B 

4500-NO3

-

E 

4500-NO3

-

E 

4500-

NO3

-

 E00 

Spectrophotometric ......................... .................. 4500-NO2

-

B 

4500-NO2

-

B 

4500-

NO2

-

 B00

Capillary Ion 

Electrophoresis

......................... D6508-00 ................. ................. ...............

20. Orthophosphate Colorimetric, 

Automated, 

Ascorbic Acid

365.16 .................. 4500-P F 4500-P F ...............

Colorimetric, 

ascorbic acid, 

single reagent

......................... D515-88 A 4500-P E 4500-P E ...............

Colorimetric 

Phosphomolybdate; 

Automatedsegmented flow; 

Automated 

Discrete

.........................

......................... 

......................... 

..................

.................. 

.................. 

.................

................. 

................. 

.................

................. 

................. 

...............

...............

............... 

I-1601-

855

I-2601-

905

I-2598-

855 

Ion 

Chromatography

300.06

300.119

D4327-97, 

03

4110 B 4110 B 4110 B00

Capillary Ion 

Electrophoresis 

......................... D6508-00 ................. ................. ...............

* * * * * * *

* * * * * 

3 Annual Book of ASTM Standards, 1994, 1996, 1999, or 2003, Vols. 11.01 and 11.02, 

ASTM International; any year containing the cited version of the method may be used. 

The previous versions of D1688-95A, D1688-95C (copper), D3559-95D (lead), D1293-
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95 (pH), D1125-91A (conductivity) and D859-94 (silica) are also approved. These 

previous versions D1688-90A, C; D3559-90D, D1293-84, D1125-91A and D859-88, 

respectively are located in the Annual Book of ASTM Standards, 1994, Vol. 11.01. Copies 

may be obtained from ASTM International, 100 Barr Harbor Drive, West Conshohocken, 

PA 19428. 

4 Standard Methods for the Examination of Water and Wastewater, 18th edition (1992), 

19th edition (1995) or 20th edition (1998). American Public Health Association, 800 I 

Street, NW, Washington, DC 20001-3710. The cited methods published in any of these 

three editions may be used, except that the versions of 3111 B, 3111 D, 3113 B and 3114 

B in the 20th edition may not be used. 

5 Method I-2601-90, Methods for Analysis by the U.S. Geological Survey National Water 

Quality Laboratory – Determination of Inorganic and Organic Constituents in Water and 

Fluvial Sediment, Open File Report 93-125, 1993; For Methods I-1030-85; I-1601-85; I1700-85; I-2598-85; I-2700-85; and I-3300-85. See Techniques of Water Resources 

Investigation of the U.S. Geological Survey, Book 5, Chapter A-1, 3rd edition, 1989; 

Available from Information Services, U.S. Geological Survey, Federal Center, Box 

25286, Denver, CO 80225-0425. 

6

 “Methods for the Determination of Inorganic Substances in Environmental Samples,” 

EPA/600/R-93/100, August 1993. Available at NTIS, PB94-120821. 
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7

 The procedure shall be done in accordance with the Technical Bulletin 601 “Standard 

Method of Test for Nitrate in Drinking Water,” July 1994, PN 221890-001, Analytical 

Technology, Inc. Copies may be obtained from ATI Orion, 529 Main Street, Boston, MA 

02129. 

8

 Method B-1011. “Waters Test Method for Determination of Nitrite/Nitrate in Water 

Using Single Column Ion Chromatography,” August, 1987. Copies may be obtained from 

Waters Corporation, Technical Services Division, 34 Maple Street, Milford, MA 01757, 

Telephone: 508/482-2963, Fax: 508/482-4056. 

* * * * * 

13 Because MDLs reported in EPA Methods 200.7 and 200.9 were determined using a 2x 

preconcentration step during sample digestion, MDLs determined when samples are 

analyzed by direct analysis (i.e., no sample digestion) will be higher. For direct analysis 

of cadmium and arsenic by Method 200.7, and arsenic by Method 3120 B, sample 

preconcentration using pneumatic nebulization may be required to achieve lower 

detection limits. Preconcentration may also be required for direct analysis of antimony, 

lead, and thallium by Method 200.9; antimony and lead by Method 3113 B; and lead by 

Method D3559-90D, unless multiple in-furnace depositions are made.
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* * * * * 

19 “Methods for the Determination of Organic and Inorganic Compounds in Drinking 

Water,” Vol. 1, EPA 815-R-00-014, August 2000. Available at NTIS, PB2000-106981. 

* * * * * 

22 Standard Methods Online are available at http://www.standardmethods.org. The year in 

which each method was approved by the Standard Methods Committee is designated by 

the last two digits in the method number. The methods listed are the only online versions 

that may be used.

3. Section 141.35 is amended as follows: 

a. In paragraph (a) by revising the third sentence,

b. By revising paragraph (b) introductory text, 

c. By revising paragraph (b)(1), 

d. In paragraph (b)(2) by revising the first sentence, 

e. By revising paragraph (c)(1), 

f. By revising paragraph (c)(2), 

g. In paragraph (c)(3)(i) by removing “May 4, 2007” and adding in its place, “June 1, 

2012,” 

h. In paragraph (c)(3)(ii) by adding a new second and third sentence, 
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i. In paragraph (c)(4) by removing “June 4, 2007” and adding in its place, “[INSERT 

DATE 150 DAYS AFTER DATE OF PUBLICATION IN FEDERAL 

REGISTER],”

j. By revising paragraph (c)(5)(i), 

k. By revising paragraph (c)(6) introductory text, 

l. By revising paragraph (c)(6)(ii), 

m. By revising paragraph (d)(1),

n. By revising paragraph (d)(2), and 

o. In the table to paragraph (e) by revising entry 6. 

The revisions and additions read as follows: 

§141.35 Reporting for unregulated contaminant monitoring results. 

(a) * * * For the purposes of this section, PWS “population served” is the retail 

population served directly by the PWS as reported to the Federal Safe Drinking Water 

Information System (SDWIS/Fed); wholesale or consecutive populations are not 

included. * * * 

(b) Reporting by all systems. You must meet the reporting requirements of this paragraph 

if you meet the applicability criteria in §141.40(a)(1) and (2).

* * * * * 

(1) Where to submit UCMR reporting requirement information. Some of your reporting 
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Page 88 of 108

requirements are to be fulfilled electronically and others by mail. Information that must 

be submitted using EPA’s electronic data reporting system must be submitted through: 

http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/ucmr3/reporting.cfm. Documentation 

that is required to be mailed can be submitted either: To UCMR Sampling Coordinator, 

USEPA, Technical Support Center, 26 West Martin Luther King Drive (MS 140), 

Cincinnati, OH 45268; or by email at UCMR_Sampling_Coordinator@epa.gov. In 

addition, you must notify the public of the availability of unregulated contaminant 

monitoring data as provided in Subpart Q (Public Notification) of this part (40 CFR 

141.207). Community Water Systems that detect unregulated contaminants under this 

monitoring must also address such detections as part of their Consumer Confidence 

Reports, as provided in Subpart O of this part (40 CFR 141.151). 

(2) * * * If you have received a letter from EPA concerning your required monitoring and 

your system does not meet the applicability criteria for UCMR established in 

§141.40(a)(1) or (2), or if a change occurs at your system that may affect your 

requirements under UCMR as defined in §141.40(a)(3) through (5), you must mail or 

email a letter to EPA, as specified in paragraph (b)(1) of this section. * * * 

* * * * * 

(c) * * * 

(1) Contact and zip code information. You must provide contact information by October 

1, 2012, and provide updates within 30 days if this information changes. The contact 
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Page 89 of 108

information must be submitted using EPA’s electronic data reporting system, as specified 

in paragraph (b)(1) of this section, and include the name, affiliation, mailing address, 

phone number, and email address for your PWS Technical Contact and your PWS 

Official. In addition, as a one-time reporting requirement, you must report the U.S. Postal 

Service Zip Code(s) for all areas being served water by your PWS. 

(2) Sampling location and inventory information. You must provide your sampling 

location and inventory information by October 1, 2012, using EPA’s electronic data 

reporting system. You must submit, verify or update the following information for each 

sampling location, or for each approved representative sampling location (as specified in 

paragraph (c)(3) of this section regarding representative sampling locations): PWS 

identification (PWSID) code; PWS facility identification code; water source type, 

sampling point identification code; and sampling point type code; (as defined in Table 1 

of paragraph (e) of this section). If this information changes, you must report updates, 

including new sources and sampling locations that are put in use before or during the 

PWS’ UCMR sampling period, to EPA’s electronic data reporting system within 30 days 

of the change. 

* * * * * 

(3) * * * 

(ii) * * * The proposed well must be representative of the highest annual volume 

producing and most consistently active wells in the representative array. If that 

representative well is not in use at the scheduled sampling time, you must select and 
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Page 90 of 108

sample an alternative representative well. * * * 

* * * * * 

(5) * * * 

(i) General rescheduling notification requirements. Large systems may change their 

Assessment Monitoring (List 1) schedule up to October 1, 2012, using EPA’s electronic 

data reporting system, as specified in paragraph (b)(1) of this section. After these dates 

have passed, if your PWS cannot sample according to your assigned sampling schedule 

(e.g., because of budget constraints, or if a sampling location will be closed during the 

scheduled month of monitoring), you must mail or email a letter to EPA, as specified in 

paragraph (b)(1) of this section, prior to the scheduled sampling date. You must include 

an explanation of why the samples cannot be taken according to the assigned schedule, 

and you must provide the alternative schedule you are requesting. You are subject to your 

assigned UCMR sampling schedule or the schedule that you revised on or before October 

1, 2012, unless and until you receive a letter from EPA specifying a new schedule.

* * * * * 

(6) Reporting monitoring results. For each sample, you must report all data elements 

specified in Table 1 of paragraph (e) of this section, using EPA’s electronic data 

reporting system. You also must report any changes, relative to what is currently posted, 

made to data elements 1 through 6 to EPA, in writing, explaining the nature and purpose 

of the proposed change, as specified in paragraph (b)(1) of this section. 

* * * * * 
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(ii) Reporting schedule. You must ensure that your laboratory posts the data to EPA’s 

electronic data reporting system within 90 days from the sample collection date (sample 

collection must occur as specified in §141.40(a)(4)). You have 30 days from when the 

laboratory posts the data in EPA’s electronic data reporting system to review, approve, 

and submit the data to the State and EPA, at the Web address specified in paragraph 

(b)(1) of this section. If you do not electronically approve and submit the laboratory data 

to EPA within 30 days of the laboratory’s posting data to EPA’s electronic reporting 

system, the data will be considered approved by you and available for State and EPA 

review.

* * * * * 

(d) * * * 

(1) Contact and zip code information. EPA will send you a notice requesting contact 

information for key individuals at your system, including name, affiliation, mailing 

address, phone number and email address. These individuals include your PWS 

Technical Contact and your PWS Official. You are required to provide this contact 

information within 90 days of receiving the notice from EPA as specified in paragraph 

(b)(1) of this section. If this contact information changes, you also must provide updates 

within 30 days of the change, as specified in paragraph (b)(1) of this section. In addition, 

as a one-time reporting requirement, you must report the U.S. Postal Service Zip Code(s) 

for all areas being served water by your PWS. 

(2) Reporting sampling information. You must record all data elements listed in Table 1 
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Page 92 of 108

of paragraph (e) of this section on each sample form and sample bottle provided to you 

by the UCMR Sampling Coordinator. You must send this information as specified in the 

instructions of your sampling kit, which will include the due date and return address. You 

must report any changes made in data elements 1 through 6 by mailing or emailing an 

explanation of the nature and purpose of the proposed change to EPA, as specified in 

paragraph (b)(1) of this section. 

(e) * * *

Table 1. Unregulated Contaminant Monitoring Reporting Requirements 

Data Element Definition

* * * * * * *

6. Disinfectant Type All of the disinfectants that have been added to the water being sampled. To be 

reported by systems for each sampling point, with possible choices being:

CLGA= Gaseous chlorine

CLOF = Offsite Generated Hypochlorite (stored as a liquid form)

CLON = Onsite Generated Hypochlorite (no storage)

CAGC = Chloramine (formed from gaseous chlorine)

CAOF = Chloramine (formed from offsite hypochlorite)

CAON = Chloramine (formed from onsite hypochlorite)

CLDO = Chlorine dioxide

OZON = Ozone

ULVL = Ultraviolet Light

OTHD = All Other Types of Disinfectant

NODU = No Disinfectant Used

* * * * * * *

Subpart E – Special Regulations, Including Monitoring Regulations and Prohibition on 

Lead Use

4. Section 141.40 is amended as follows: 

a. By revising paragraph (a) introductory text, 
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b. By revising paragraph (a)(1),

c. By revising paragraph (a)(2)(i) introductory text, 

d. By revising the first sentence of paragraph (a)(2)(i)(A), 

e. By revising paragraph (a)(2)(ii) introductory text, 

f. By revising paragraph (a)(2)(ii)(A), 

g. By revising paragraph (a)(2)(ii)(C),

h. By revising paragraph (a)(3),

i. In paragraph (a)(4)(i) introductory text by removing “August 2, 2007” and adding in its 

place, “October 1, 2012”, 

j. By revising paragraph (a)(4)(i)(B), 

k. By revising paragraph (a)(4)(i)(C), 

l. In paragraph (a)(4)(i)(D) by removing the last sentence, 

m. By revising paragraph (a)(4)(ii)(G), 

n. In paragraph (a)(5)(ii) by removing “April 4, 2007” and adding in its place, “[INSERT 

DATE 90 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL 

REGISTER]” and by revising the last sentence, 

o. By revising paragraph (a)(5)(iii) introductory text, 

p. By revising paragraph (a)(5)(iii)(A)(1),

q. By revising paragraph (a)(5)(iv), and 

r. By revising paragraph (a)(5)(vi).

The revisions read as follows: 
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§141.40 Monitoring requirements for unregulated contaminants.

(a) General applicability. This section specifies the monitoring and quality control 

requirements that must be followed if you own or operate a public water system (PWS) 

that is subject to the Unregulated Contaminant Monitoring Regulation (UCMR), as 

specified in paragraphs (a)(1) and (2) of this section. In addition, this section specifies the 

UCMR requirements for State and Tribal participation. For the purposes of this section, 

PWS “population served,” “State,” “ PWS Official,” “PWS Technical Contact,” and 

“finished water” apply as defined in §141.35(a). The determination of whether a PWS is 

required to monitor under this rule is based on the type of system (e.g., community water 

system, non-transient non-community water system, etc.), and its retail population, as 

indicated by SDWIS/Fed on December 31, 2010. 

(1) Applicability to transient non-community systems. If you own or operate a transient 

non-community water system, and you are notified by your State or EPA, you must 

permit the State, EPA or their contractors to collect samples for the contaminants 

specified on List 3 of Table 1, in paragraph (a)(3) of this section. 

(2) * * * 

(i) Large systems. If you own or operate a retail PWS (other than a transient noncommunity system) that serves more than 10,000 people, you must monitor according to 

the specifications in this paragraph (a)(2)(i). If you believe that your applicability status is 

different than EPA has specified in the notification letter that you received, or if you are 

subject to UCMR requirements and you have not been notified by either EPA or your 
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State, you must report to EPA, as specified in §141.35(b)(2) or (c)(4). 

(A) Assessment Monitoring. You must monitor for the unregulated contaminants on List 

1 and Total Chromium per Table 1, UCMR Contaminant List, in paragraph (a)(3) of this 

section. * * * 

* * * * * 

(ii) Small systems. Small PWSs, as defined in this paragraph, will not be selected to 

monitor for any more than one of the three monitoring lists provided in Table 1, UCMR 

Contaminant List, in paragraph (a)(3) of this section. EPA will provide sample 

containers, provide pre-paid air bills for shipping the sampling materials, conduct the 

laboratory analysis, and report and review monitoring results for all small systems 

selected to conduct monitoring under paragraphs (a)(2)(ii)(A) through (C) of this section. 

If you own or operate a PWS that serves 10,000 or fewer people you must monitor as 

follows: 

(A) Assessment Monitoring. You must monitor for the unregulated contaminants on List 

1 and Total Chromium per Table 1, in paragraph (a)(3) of this section, if you are notified 

by your State or EPA that you are part of the State Monitoring Plan for Assessment 

Monitoring. 

* * * * * 

(C) Pre-Screen Testing. You must allow EPA or its representative to collect samples to 

support monitoring for the unregulated contaminants on List 3 of Table 1, in paragraph 

(a)(3) of this section, if you are notified by your State or EPA that you are part of the 

State Monitoring plan for Pre-Screen Testing. In addition, you must permit the collection 
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of samples as necessary for EPA to perform analysis for total coliforms, E. coli, 

bacteriophage, Enterococci and aerobic spores. 

(3) Analytes to be monitored. Lists 1, 2, and 3 of unregulated contaminants and total 

chromium monitoring are provided in the following table: 

Table 1. UCMR Contaminant List

List 1: Assessment Monitoring

Chemical Contaminants

1-Contaminant 2-CAS 

Registry 

Number

3-Analytical 

Methods a

4-Minimum 

Reporting 

Level b

5-Sampling 

Location c

6-Period During 

Which Monitoring to 

be Completed

Hormones

17-β-estradiol 50-28-2 EPA 539 d 0.0004 μg/L EPTDS 1/1/2013 - 12/31/2015

17-α-ethynylestradiol 57-63-6 EPA 539 d 0.0009 μg/L EPTDS 1/1/2013 - 12/31/2015

estriol 50-27-1 EPA 539 d 0.0008 μg/L EPTDS 1/1/2013 - 12/31/2015

equilin 474-86-2 EPA 539 d 0.004 μg/L EPTDS 1/1/2013 - 12/31/2015

estrone 53-16-7 EPA 539 d 0.002 μg/L EPTDS 1/1/2013 - 12/31/2015

testosterone 58-22-0 EPA 539 d 0.0001 μg/L EPTDS 1/1/2013 - 12/31/2015

4-androstene-3,17-dione 63-05-8 EPA 539 d 0.0003 μg/L EPTDS 1/1/2013 - 12/31/2015

Volatile Organic Compounds

1,2,3-trichloropropane 96-18-4 EPA 524.3 e 0.03 μg/L EPTDS 1/1/2013 - 12/31/2015

1,3-butadiene 106-99-0 EPA 524.3 e 0.1 μg/L EPTDS 1/1/2013 - 12/31/2015

chloromethane 74-87-3 EPA 524.3 e 0.2 μg/L EPTDS 1/1/2013 - 12/31/2015

1,1-dichloroethane 75-34-3 EPA 524.3 e 0.03 μg/L EPTDS 1/1/2013 - 12/31/2015

n-propylbenzene 103-65-1 EPA 524.3 e 0.03 μg/L EPTDS 1/1/2013 - 12/31/2015

bromomethane 74-83-9 EPA 524.3 e 0.2 μg/L EPTDS 1/1/2013 - 12/31/2015

chlorodifluoromethane (HCFC22)75-45-6 EPA 524.3 e 0.08 μg/L EPTDS 1/1/2013 - 12/31/2015
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bromochloromethane (Halon 

1011)

74-97-5 EPA 524.3 e 0.06 μg/L EPTDS 1/1/2013 - 12/31/2015

Synthetic Organic Compound

1,4-dioxane 123-91-1 EPA 522 f 0.07 μg/L EPTDS 1/1/2013 - 12/31/2015

Metals

vanadium 7440-62-2 EPA 200.8

ASTM 

D5673-10

SM 3125 g

0.2 μg/L EPTDS and 

DSMRT

1/1/2013 - 12/31/2015

molybdenum 7439-98-7 EPA 200.8

ASTM 

D5673-10

SM 3125 g

1. μg/L EPTDS and 

DSMRT

1/1/2013 - 12/31/2015

cobalt 7440-48-4 EPA 200.8

ASTM 

D5673-10

SM 3125 g

1. μg/L EPTDS and 

DSMRT

1/1/2013 - 12/31/2015

strontium 7440-24-6 EPA 200.8

ASTM 

D5673-10

SM 3125 g

0.3 μg/L EPTDS and 

DSMRT

1/1/2013 - 12/31/2015

Chromium-6

chromium-6k 18540-29-9 EPA 218.7h 0.03 μg/L EPTDS and 

DSMRT

1/1/2013 - 12/31/2015

Oxyhalide Anion

chlorate 14866-68-3 EPA 300.1

ASTM D 

6581-08

SM 4110D i

20 μg/L EPTDS and 

DSMRT

1/1/2013 - 12/31/2015

Perfluorinated Compounds

perfluorooctanesulfonic acid 

(PFOS)

1763-23-1 EPA 537 j 0.04 μg/L EPTDS 1/1/2013 - 12/31/2015

perfluorooctanoic acid (PFOA) 335-67-1 EPA 537 j 0.02 μg/L EPTDS 1/1/2013 - 12/31/2015

perfluorononanoic acid (PFNA) 375-95-1 EPA 537 j 0.02 μg/L EPTDS 1/1/2013 - 12/31/2015

perfluorohexanesulfonic acid 

(PFHxS)

355-46-4 EPA 537 j 0.03 μg/L EPTDS 1/1/2013 - 12/31/2015

perfluoroheptanoic acid 375-85-9 EPA 537 j 0.01 μg/L EPTDS 1/1/2013 - 12/31/2015
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List 2: Screening Survey

1-Contaminant 2-CAS 

Registry 

Number

3-Analytical

Methods a

4-Minimum 

Reporting 

Level b

5-Sampling 

Location c

6-Period During 

Which Monitoring to 

be Completed

Reserved Reserved Reserved Reserved Reserved Reserved

List 3: Pre-Screen Testing

Microbiological Contaminants

1-Contaminant 2-CAS 

Registry 

Number

3-Analytical

Methods a

4-Minimum 

Reporting 

Level b

5-Sampling 

Location c

6-Period During 

Which Monitoring to 

be Completed

enteroviruses N/A N/A N/A EPTDS 1/1/2013-12/31/2015

noroviruses N/A N/A N/A EPTDS 1/1/2013 - 12/31/2015

Total Chromium Monitoring

1-Contaminant 2-CAS 

Registry 

Number

3-Analytical

Methods a

4-Minimum 

Reporting 

Level b

5-Sampling 

Location c

6-Period During 

Which Monitoring to 

be Completed

total chromium N/A EPA 200.8

ASTM 

D5673-10

SM 3125g

0.2 μg/L EPTDS and 

DSMRT

1/1/2013 - 12/31/2015

Column headings are: 

1-Contaminant: the name of the contaminant to be analyzed. 

2-CAS (Chemical Abstract Service) Registry Number or Identification Number: a unique 

number identifying the chemical contaminants.

(PFHpA)

perfluorobutanesulfonic acid 

(PFBS)

375-73-5 EPA 537 j 0.09 μg/L EPTDS 1/1/2013 - 12/31/2015
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3-Analytical Methods: method numbers identifying the methods that must be used to test 

the contaminants. For List 3, analysis will only be performed by laboratories under 

contract to EPA.

4-Minimum Reporting Level: the value and unit of measure at or above which the 

concentration of the contaminant must be measured using the approved analytical 

methods. If EPA determines, after the first six months of monitoring, that the MRLs 

specified in UCMR 3 result in excessive resampling, EPA will establish alternate MRLs 

and will notify affected PWSs and laboratories of the new MRLs. For List 3, minimum 

reporting level is based on volume of water filtered and PCR amplification level.

5-Sampling Location: the locations within a PWS at which samples must be collected.

6-Period During Which Monitoring to be Completed: the time period during which the 

sampling and testing will occur for the indicated contaminant. 

a The analytical procedures shall be performed in accordance with the documents 

associated with each method (per the following footnotes). The incorporation by 

reference of the following documents listed in footnotes d through j was approved by the 

Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 

Information on how to obtain these documents can be provided by the Safe Drinking 

Water Hotline at (800) 426-4791. Publically available docket materials are available 

either electronically in www.regulations.gov or in hard copy at the Water Docket. The 

Docket ID is EPA-OW-2009-0090. Hard copies of these documents may be viewed at the 

Water Docket in the EPA Docket Center, (EPA/DC) EPA West, Room 3334, 1301 

Constitution Avenue, NW, Washington, DC. The EPA Docket Center Public Reading 
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Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 

holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the 

telephone number for the Water docket is (202) 566-2426. Copyrighted materials are 

only available for viewing in hard copy. These documents may also be viewed at the 

National Archives and Records Administration (NARA). For information on the 

availability of this material at NARA, call 1-866-272-6272 or go to: 

http://www.archives.gov/locations/.

b The minimum reporting level (MRL) is the minimum concentration of each analyte that 

must be reported to EPA. 

c Sampling must occur at entry points to the distribution system (EPTDSs) after treatment 

is applied that represent each non-emergency water source in routine use over the 12-

month period of monitoring. Systems that purchase water with multiple connections from 

the same wholesaler may select one representative connection from that wholesaler. This 

EPTDS sampling location must be representative of the highest annual volume 

connections. If the connection selected as the representative EPTDS is not available for 

sampling, an alternate highest volume representative connection must be sampled. See 40 

CFR 141.35(c)(3) for an explanation of the requirements related to use of representative 

ground water EPTDSs. Sampling for total chromium, chromium-6, cobalt, molybdenum, 

strontium, vanadium, and chlorate must be conducted at distribution system maximum 

residence time (DSMRT) sampling locations. DSMRT is defined as an active point (i.e., 

a location that currently provides water to customers) in the distribution system where the 

water has been in the system the longest relative to the EPTDS. 
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d

 EPA Method 539 “Determination of Hormones in Drinking Water by Solid Phase 

Extraction (SPE) and Liquid Chromatography Electrospray Ionization Tandem Mass 

Spectrometry (LC-ESI-MS/MS),” Version 1.0, November 2010, EPA 815-B-10-001 is 

available at 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

e

 EPA Method 524.3 “Measurement of Purgeable Organic Compounds in Water by 

Capillary Column Gas Chromatography/Mass Spectrometry,” Version 1.0, June 2009, 

EPA 815-B-09-009 is available at 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

f

 EPA Method 522 “Determination of 1,4-Dioxane in Drinking Water by Solid Phase 

Extraction (SPE) and Gas Chromatography/Mass Spectrometry (GC/MS) with Selected 

Ion Monitoring (SIM),” Version 1.0, September 2008, EPA 600-R-08-101 is available at 

http://www.epa.gov/nerlcwww/ordmeth.htm. 

g

 EPA Method 200.8 “Determination of Trace Elements in Waters and Wastes by 

Inductively Coupled Plasma - Mass Spectrometry,” Version 5.4, 1994 is available at 

http://www.NEMI.gov. 

ASTM D5673-10 “Standard Test Method for Elements in Water by Inductively Coupled 

Plasma-Mass Spectrometry,” is available for purchase at 

http://www.astm.org/Standards/D5673.htm. 

SM 3125 “Metals by Inductively Coupled Plasma/Mass Spectrometry,” Standard 

Methods for the Examination of Water and Wastewater, 21st edition (2005). American 

Public Health Association, 800 I Street, NW, Washington, DC 20001-3710. 
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h

 EPA Method 218.7 “Determination of Dissolved Hexavalent Chromium in Drinking 

Water by Ion Chromatography,” Version 1.0, September 2011, EPA TSC-3-0768 is 

available at 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

i

 EPA Method 300.1 “Determination of Inorganic Anions in Drinking Water by Ion 

Chromatography,” Revision 1.0, 1997 is available at 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. 

ASTM D6581-08 “Standard Test Methods for Bromate, Bromide, Chlorate, and Chlorite 

in Drinking Water by Suppressed Ion Chromatography,” Available for purchase on the 

Internet at http://www.astm.org/Standards/D6581.htm. 

SM 4110D “Determination of Anions by Ion Chromatography, Part D, Ion 

Chromatography Determination of Oxyhalides and Bromide,” Standard Methods for the 

Examination of Water and Wastewater, 21st edition (2005). American Public Health 

Association, 800 I Street, NW, Washington, DC 20001-3710. 

j EPA Method 537 “Determination of Selected Perfluorinated Alkyl Acids in Drinking 

Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass 

Spectrometry (LC/MS/MS),” Version 1.1, September 2009, EPA 600-R-08-092 is 

available at http://www.epa.gov/nerlcwww/ordmeth.htm. 

k

 Chromium-6 will be measured as soluble chromate ion (CAS Registry Number 13907-

45-4). 

* * * * * 
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(4) * * * 

(i) * * *

(B) Frequency. You must collect the samples within the time frame and according to the 

frequency specified by contaminant type and water source type for each sampling 

location, as specified in Table 2, in this paragraph. For the second or subsequent round of 

sampling, if a sample location is non-operational for more than one month before and one 

month after the scheduled sampling month (i.e., it is not possible for you to sample within 

the window specified in Table 2, in this paragraph), you must notify EPA as specified in 

§141.35(c)(5) to reschedule your sampling. 

Table 2. Monitoring Frequency by Contaminant and Water Source Types

Contaminant Type Water Source Type Time Frame Frequency

Chemical Surface water or

ground water under the direct 

influence of surface water 

(GWUDI) (includes all sampling 

locations for which some or all of 

the water comes from a surface 

water or GWUDI source at any 

time during the 12 month 

monitoring period) 

12 months You must monitor for 

4 consecutive quarters. 

Sample events must 

occur 3 months apart. 

Ground water 12 months You must monitor 

twice in a consecutive 

12-month period. 

Sample events must 

occur 5 - 7 months 

apart.
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Microbiological Ground water 12 months You must monitor 

twice in a consecutive 

12-month period. 

Sample events must 

occur 5 - 7 months 

apart.

(C) Location. You must collect samples for each List 1 Assessment Monitoring 

contaminant, and, if applicable, for each List 2 Screening Survey, or List 3 Pre-Screen 

Testing contaminant, as specified in Table 1, in paragraph (a)(3) of this section. Samples 

must be collected at each sample point that is specified in column 5 and footnote c of 

Table 1, in paragraph (a)(3) of this section. If you are a ground water system with 

multiple EPTDSs, and you request and receive approval from EPA or the State for 

sampling at representative EPTDS(s), as specified in §141.35(c)(3), you must collect 

your samples from the approved representative sampling location(s). Systems conducting 

Assessment Monitoring must also sample for total chromium, chromium-6, cobalt, 

molybdenum, strontium, vanadium, and chlorate at the location that represents the 

maximum residence time in the distribution system (DSMRT). DSMRT is defined as an 

active point (i.e., a location that currently provides water to customers) in the distribution 

system where the water has been in the system the longest relative to the EPTDS. 

(ii) * * *

* * * * * 

(G) Sampling forms. You must completely fill out each of the sampling forms and bottles 
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sent to you by the UCMR Sampling Coordinator, including data elements listed in 

§141.35(e) for each sample, as specified in §141.35(d)(2). You must sign and date the 

sampling forms.

* * * * * 

(5) * * * 

* * * * * 

(ii) * * * Correspondence must be addressed to: UCMR Laboratory Approval 

Coordinator, USEPA, Technical Support Center, 26 West Martin Luther King Drive, 

(MS 140), Cincinnati, OH 45268; or emailed to EPA at: 

UCMR_Sampling_Coordinator@epa.gov. 

(iii) Minimum Reporting Level. The MRL is an estimate of the quantitation limit. 

Assuming good instrumentation and experienced analysts, an MRL is achievable, with 

95% confidence, by 75% of laboratories nationwide. 

(A) * * *

(1) All laboratories performing analysis under UCMR must demonstrate that they are 

capable of meeting data quality objectives at or below the MRL listed in Table 1, column 

4, in paragraph (a)(3) of this section. 

* * * * * 

(iv) Laboratory fortified sample matrix and laboratory fortified sample matrix duplicate. 
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You must ensure that your laboratory prepares and analyzes the Laboratory Fortified 

Sample Matrix (LFSM) sample for accuracy and Laboratory Fortified Sample Matrix 

Duplicate (LFSMD) samples for precision to determine method accuracy and precision 

for all contaminants in Table 1, in paragraph (a)(3) of this section. LFSM/LFSMD 

samples must be prepared using a sample collected and analyzed in accordance with 

UCMR requirements and analyzed at a frequency of 5% (or 1 LFSM/LFSMD set per 

every 20 samples) or with each sample batch, whichever is more frequent. In addition, 

the LFSM/LFSMD fortification concentrations must be alternated between a low-level 

fortification and mid-level fortification approximately 50% of the time. (For example: a 

set of 40 samples will require preparation and analysis of 2 LFSM/LFSMD paired 

samples. The first LFSM/LFSMD paired sample set must be fortified at either the lowlevel or mid-level, and the second LFSM/LFSMD paired sample set must be fortified 

with the other standard, either the low-level or mid-level, whichever was not used for the 

initial LFSM/LFSMD paired sample set.) The low-level LFSM/LFSMD fortification 

concentration must be within ±50% of the MRL for each contaminant (e.g., for an MRL 

of 1 μg/L the acceptable fortification levels must be between 0.5 μg/L and 1.5 μg/L). The 

mid-level LFSM/LFSMD fortification concentration must be within ±20% of the midlevel calibration standard for each contaminant, and is to represent, where possible and 

where the laboratory has data from previously analyzed samples, an approximate average 

concentration observed in previous analyses of that analyte. There are no UCMR 

contaminant recovery acceptance criteria specified for LFSM/LFSMD analyses. All 

LFSM/LFSMD data are to be reported.
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* * * * * 

(vi) Reporting You must require your laboratory to submit these data electronically to the 

State and EPA using EPA’s electronic data reporting system, accessible at 

(http://water.epa.gov/lawsregs/rulesregs/sdwa/ucmr/ucmr3/reporting.cfm), within 90 days 

from the sample collection date. You then have 30 days from when the laboratory posts 

the data to review, approve and submit the data to the State and EPA, via EPA’s 

electronic data reporting system. If you do not electronically approve and submit the 

laboratory data to EPA within 30 days of the laboratory posting data to EPA’s electronic 

reporting system, the data will be considered approved and available for State and EPA 

review. 

* * * * * 

PART 142 - NATIONAL PRIMARY DRINKING WATER REGULATIONS

IMPLEMENTATION

5. The authority citation for part 142 continues to read as follows:

Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 

300j-9, and 300j-11. 

Subpart B – Primary Enforcement Responsibility

6. Section 142.16 is amended as follows: 
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a. In paragraph (j) introductory text by removing “§141.40”. 

b. In paragraph (j)(1) by revising the first sentence. 

§142.16 Special primacy requirements. 

* * * * * 

(j) * * *

(1) If a State chooses to issue waivers from the monitoring requirements in §§141.23 and 

141.24, the State shall describe the procedures and criteria which it will use to review 

waiver applications and issue wavier determinations. * * * 

* * * * *