Response to 

Comments Document 

for the Unregulated 

Contaminant

Monitoring 

Regulation (UCMR 3)
Office of Water (4607M)

EPA 815-R-11-004

January 2012

http://water.epa.gov/drink/
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Table of Contents

1. INTRODUCTION AND OVERVIEW ............................................................................................ 1

Background .................................................................................................................................................. 1

EPA’s Categorization of Public Comments and Document Organization ........................................ 1

Comments and Responses by Comment Code – Section 2 ................................................................. 1

Response to Comment Code .................................................................................................................... 2

Cross Referencing of Responses............................................................................................................... 2

Who Submitted Comments....................................................................................................................... 2

2. COMMENTS AND EPA RESPONSES BY COMMENT CODE ........................................................ 3

10000 General Comments......................................................................................................................... 3

20000 Sampling Design and Reporting ................................................................................................... 8

21000 Assessment Monitoring................................................................................................................11

22000 Pre-Screen Testing ........................................................................................................................12

23000 Other Changes between UCMR 2 and UCMR 3 .....................................................................17

23100 Transient Systems..........................................................................................................................23

23200 Retail Population Based Applicability ........................................................................................25

23300 Ground Water Representative Monitoring Locations .............................................................39

23400 Sampling Requirements Frequency ............................................................................................47

23500 Revised Data Element #4 - Zip Codes ......................................................................................49

23600 Revised Data Element #6 - Disinfectant Type ........................................................................59

23800 Revised Reporting Time Frames................................................................................................. 64

23810 Laboratory Reporting Time .........................................................................................................70

23820 PWS Review Time.........................................................................................................................75

24000 Reporting System/SDWARS ......................................................................................................80

30000 Potential UCMR 3 Contaminants...............................................................................................88

31000 Hormones.......................................................................................................................................97

31010 EPA Method 539 - Hormones ................................................................................................. 108

31050 Health Effects - Hormones ...................................................................................................... 126

31600 Testosterone................................................................................................................................ 134

32000 Volatile Organic Compounds (VOCs) .................................................................................... 136

32010 EPA Method 524.3 - VOCs ..................................................................................................... 139

32020 Other Methods - VOCs ............................................................................................................ 143

32100 1,2,3-Trichloropropane .............................................................................................................. 145

32200 1,3-Butadiene .............................................................................................................................. 147

32400 1,1-Dichloroethane .................................................................................................................... 151

32800 Chlorodifluoromethane (HCFC-22)........................................................................................ 152

33010 EPA Method 522 - 1,4-Dioxane .............................................................................................. 154

33100 1,4-Dioxane................................................................................................................................. 160
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34000 Metals........................................................................................................................................... 162

34010 EPA Method 200.8 Rev 5.4 - Metals....................................................................................... 164

34030 SM 3125 (1997) - Metals ........................................................................................................... 171

34040 Other Methods - Metals............................................................................................................ 172

34050 Sampling Location - Metals...................................................................................................... 173

34070 Health Effects - Metals.............................................................................................................. 186

34100 Vanadium..................................................................................................................................... 188

34200 Molybdenum............................................................................................................................... 190

34300 Cobalt........................................................................................................................................... 193

34400 Strontium..................................................................................................................................... 194

35010 EPA Method 300.1 - Chlorate ................................................................................................. 196

35030 SM 4110D (1997) - Chlorate .................................................................................................... 197

35040 Other Methods - Chlorate ........................................................................................................ 199

35050 Sampling Location - Chlorate ................................................................................................... 200

35100 Chlorate ....................................................................................................................................... 210

36000 Perfluorinated Compounds (PFCs) ......................................................................................... 211

36010 EPA Method 537 Rev 1.1 - PFCs............................................................................................ 219

36020 Other Methods - PFCs.............................................................................................................. 237

36050 Health Effects - PFCs................................................................................................................ 239

36100 Perfluorooctane sulfonic acid (PFOS) .................................................................................... 240

36200 Perfluorooctanoic acid (PFOA)............................................................................................... 241

36600 Perfluorobutanesulfonic acid (PFBS) ...................................................................................... 243

37000 Viruses.......................................................................................................................................... 250

37010 EPA Method 1615 - Viruses..................................................................................................... 263

37030 Sampling Location - Viruses..................................................................................................... 266

37035 Sampling Methodology - Viruses............................................................................................. 267

37050 Borchardt Data - Viruses .......................................................................................................... 271

37300 General Indicators...................................................................................................................... 274

37400 Aerobic EndoSpores.................................................................................................................. 275

38000 Other Contaminants.................................................................................................................. 276

38100 Chromium-6 ................................................................................................................................ 285

38110 EPA Method 218.7 - Chromium-6 .......................................................................................... 325

38120 Other Methods - Chromium-6 ................................................................................................. 331

38130 Sampling Location - Chromium-6 ........................................................................................... 332

38200 Total Chromium......................................................................................................................... 335

38210 EPA Method 200.8 Rev 5.4 - Total Chromium .................................................................... 352

38250 Sampling Location - Total Chromium .................................................................................... 355

40000 Minimum Reporting Level Determination/LCMRLs.......................................................... 356

41000 Laboratory Approval Process/Laboratory Capacity ............................................................. 383
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60000 Interrelationship of CCL, UCMR, NCOD and RegDet ...................................................... 387

70000 Cost Estimates/ICR .................................................................................................................. 390

80000 Environmental Justice Approach ............................................................................................. 395

90000 Comments Outside the Scope of UCMR 3 ............................................................................ 397

APPENDIX 1 – COMPLETE LIST OF EPA COMMENT CODES ................................................... 398

List of Exhibits

Exhibit 1: Public Submissions by Commenter Type .................................................................................... 2
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1. Introduction and Overview

Background

The 1996 amendments to the Safe Drinking Water Act (SDWA) (section 1445) require the United 

States Environmental Protection Agency (EPA) to promulgate regulations for the monitoring of 

“unregulated” contaminants. Unregulated contaminant monitoring rules are codified in part 141 of 

the Code of Federal Regulations (CFR). These rules have been substantially revised by requirements 

of the 1996 SDWA amendments, which specify that EPA develop a new list of not more than 30 

contaminants every 5 years for public water system monitoring. The results of this monitoring are to 

be used in determining, on a national basis, the concentration and spatial distribution of these 

contaminants, and related information regarding their occurrence in public drinking water. The 

regulations establish criteria for listing contaminants and for carrying out the monitoring program. 

Other components of the unregulated contaminant monitoring program require that: the data 

collected are placed into the National Contaminant Occurrence Database (NCOD); that only a 

representative sample of public water systems serving 10,000 or fewer people will be sampled; and 

that consumers will be informed of the monitoring results (e.g., Consumer Confidence Reports). 

EPA published the proposed rule for the third round of monitoring, titled "Revisions to the 

Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems," on March 

3, 2011 (76 FR 11713) and requested public comment. Fifty-three public submissions (in the form 

of letters, emails, and/or postings to www.regulations.gov) were received by EPA. All original public 

submissions can be found in their respective docket locations; at www.regulations.gov, under 

Docket ID EPA–HQ–OW–2009–0090.

EPA’s Categorization of Public Comments and Document Organization

EPA sought public comment on a number of topics, including: proposed contaminants and 

associated analytical methods; inclusion of certain data elements; time frames; and several other 

issues. Anticipating the public comments that might be received, and to allow the comments to be 

organized as they were received, EPA developed a list of numerically ordered topics (referred to as 

“EPA Comment Codes”). Not all of the topics associated with the EPA Comment Codes were 

addressed by commenters. The complete list of EPA Comment Codes is provided in Appendix 1, 

including notation for codes that did not receive comments. 

To give each public submission a unique identifier, and to tie each submission to the docket for the 

Federal Register, EPA assigned a unique document ID to each submission. Each public submission 

was read by EPA, and, where appropriate, was subdivided into “comment sections,” or distinct issue 

areas, based on topical breaks within the submission. EPA grouped these comment sections 

(hereinafter referred to as “comments”) and assigned a five digit “EPA Comment ID.” Comments 

that were similar in topic were then grouped together into a corresponding EPA Comment Code. 

Comments and Responses by Comment Code – Section 2

Section 2 presents the public comments and EPA’s responses. These are organized first by EPA 

Comment Code, then organized numerically by EPA Comment ID. Readers can first find the 

Comment Code for topics they are interested in, and then find responses to specific Comment IDs 

for individual comments. The commenter name, organization, and Document ID are also given for 

each comment. Any comment can be read as it appears within the commenter’s original letter, email, 

or posting by searching on the associated Document ID on www.regulations.gov (see explanation of 

Document IDs in the previous section “EPA’s Categorization of Public Comments and Document 
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Organization”). The Document ID can also be used to find additional information, such as tables or 

figures, which may be included within the context of comments or attachments in the commenter’s 

original submission. 

Response to Comment Code

Many comments submitted to EPA addressed similar topics, and were thus grouped under the same 

EPA Comment Code. In several of these cases, the same response was appropriate for multiple 

comments, and EPA developed a “Response to Comment Code” that appears at the beginning of 

each EPA Comment Code section. Where appropriate, responses to individual comments point 

reader to the associated Response to Comment Code. 

Cross Referencing of Responses

As appropriate, EPA has cross referenced responses to avoid redundancy and to ensure consistency. 

Responses are cross referenced by providing the pertinent EPA Comment ID, along with the EPA 

Comment Code where the EPA Comment ID is located. As noted above, Section 2 is organized 

first by EPA Comment Code (the subsections within the chapter), then numerically by EPA 

Comment ID.

Who Submitted Comments

EPA grouped commenters into nine categories to provide a broad characterization of interested 

stakeholders. Exhibit 1, below, lists commenter category, and the number of comments received 

within each category.

Exhibit 1: Public Submissions by Commenter Type

Organization Number of Commenters1

1. Fifty-eight public letters have been received to date. However, 3 are duplicate submissions, and 2 comments were 

submitted to the wrong docket, resulting in 53 comments on UCMR 3. 

Private Citizen/Anonymous 7

Local Government 3

Industry Group 7

Federal Government 1

Drinking Water System 11

Drinking Water Organization 7

Individual Manufacturers/Companies 6

Environmental Group 3

State and Territories 9

Total 53
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2. Comments and EPA Responses by Comment Code

Comment Code: 10000 General Comments

Summary Response to General Comments: The agency agrees that protecting drinking water is 

an important part of protecting public health. Protecting drinking water is the responsibility of many 

stakeholders such as public water systems, tribes, laboratories, states and the public. 

Individual Comments

Commenter Name: Debra Hahn

Commenter Organization:

Letter ID: 0040

Comment ID: 31600

Comment Code: 10000

Comment: I approve of testing for the 28 contaminants and 2 viruses. I approve of laboratory 

Environmental Protection Agency regulation for analyzing the contaminants. 

Response: Please see response to comment code 10000 General Comments.

Commenter Name: Anonymous 

Commenter Organization:

Letter ID: 0043

Comment ID: 31604

Comment Code: 10000

Comment: This is a wonderful idea. Do it. 

Response: Please see response to comment code 10000 General Comments.

Commenter Name:

Commenter Organization: Northern Kentucky Water District

Letter ID: 0060

Comment ID: 31649

Comment Code: 10000

Comment: On page 11718 Exhibit 3, under the "4 Metals using EPA Method 200.8 (IC/MS)", the 

"P" is missing in the instrument abbreviation. The footnote indicates "ICP/MS".

Response: EPA acknowledges the typographical error and has made the appropriate correction. 

Commenter Name: Diane VanDe Hei
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Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31783

Comment Code: 10000

Comment: Additional Recommendation: Watershed Protection - leveraging other statutes

EPA’s Drinking Water and Clean Water Strategies support preventing the entry of contaminants 

into drinking water sources as being a more effective and economical means of improving or 

maintaining source water quality than trying to remove contaminants through drinking water 

treatment. Furthermore, it helps insure that the burden of reducing contaminants falls on those 

introducing the contaminants to the environment rather than drinking water consumers. Therefore 

AMWA encourages EPA to use the data gathered under the UCMR and its other programs to 

leverage other statutes - such as TSCA and FIFRA - to protect drinking water. 

Response: Consistent with the Administrator's Drinking Water Strategy, EPA is working with other 

Agency programs to leverage other statutes.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31819

Comment Code: 10000

Comment: Comments by Texas Commission on Environmental Quality on the Proposed Revisions 

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

(PWSs)

EPA Docket ID No. OW-2009-0090

UCMR 3 Summary

The U.S. Environmental Protection Agency (EPA) proposed the Revisions to the Unregulated 

Contaminant Monitoring Regulation on March 3, 2011, as required by the US Congress. The 1996 

amendments to the Safe Drinking Water Act (SDWA) require that the EPA establish a program to 

monitor at public water systems (PWSs) for unregulated contaminants, to approve and develop 

associated analytical methods, and to publish a list of monitored contaminants every five years. The 

EPA is proposing UCMR 3 monitoring for twenty-eight new chemicals and two viruses, for a total 

of thirty contaminants. 

TCEQ Comments on UCMR 3 

Sound science 

The EPA's UCMR 3 process is intended to ensure that the EPA uses sound science to make 

regulatory determinations. 
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The Texas Commission on Environmental Quality (TCEQ) generally supports the goal of ensuring 

that any future regulations are based on sound science, and therefore supports the CCL process 

under which a potential list of approximately 7,500 potential candidate contaminants was reduced to 

the current list of 30. 

Response: Please see response to comment code 10000 General Comments.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31870

Comment Code: 10000

Comment: Minor typographical errors:

* Under the Table 1-UCMR contaminant list (page 11734), the sampling location for testosterone is 

listed at EPDTS. It should be EPTDS. 

* Although not a typographical error, ASDWA recommends that EPA consider a minor change 

under Table 2 - Monitoring Frequency by Contaminant and Water Source Types (page 11736), 

modifying the sampling window for surface water sources to 12-14 weeks apart rather than precisely 

3 months. This matches the use of a range for ground water systems and provides a little more 

flexibility for water systems under the rule.

Response: EPA acknowledges the EPTDS typographical error and has made the appropriate 

correction. EPA is maintaining the requirement for surface water system sampling events to occur 3 

months apart; however, EPA has added an example to Table 2 clarifying that if the first monitoring 

is in January, the second monitoring must occur any time in April, the third any time in July and the 

fourth any time in October. This provides even more flexibility then suggested by the commenter. 

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31888

Comment Code: 10000

Comment: In general, the NJDEP supports the program improvements that have been 

incorporated into the UCMR3, based on the USEPA’s experience implementing the UCMR1 and 

UCMR2 monitoring programs, such as clarification of the representative groundwater sampling 

locations, timeframes for reporting of laboratory results, and revisions to the data elements reported. 

Response: Please see response to comment code 10000 General Comments.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)
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Letter ID: 0080

Comment ID: 32044

Comment Code: 10000

Comment: COMMENTS BY THE AMERICAN WATER WORKS ASSOCIATION ON THE 

PROPOSED THIRD UNREGULATED CONTAMINANT MONITORING RULE

General

The American Water Works Association (AWWA) is an international, nonprofit, scientific and 

educational society dedicated to the improvement of drinking water quality and supply. Founded in 

1881, the Association is the largest organization of water supply professionals in the world. Our 

54,000-plus members represent the full spectrum of the drinking water community: treatment plant 

operators and managers, environmental advocates, scientists, academicians, and others who hold a 

genuine interest in water supply and public health. Our membership includes more than 4,000 

utilities that supply roughly 80 percent of the nation's drinking water. Protecting public health is an 

essential goal of the drinking water profession and the mission of each public water system.

Comments on Stakeholder Draft of UCMR3 AWWA appreciates the outreach to stakeholders that 

occurred prior to this proposed rule. The stakeholder meeting U.S. EPA organized on April 7, 2010, 

was very helpful and provided AWWA an opportunity to better understand the proposed changes to 

the UCMR in this third cycle (UCMR3). As was noted at the meeting and in AWWA’s subsequent 

written comments, UCMR3 will be an important data collection opportunity if appropriately 

implemented. And, overall, AWWA found EPA’s approach to developing UCMR3 to be sound. 

During the stakeholder draft review, AWWA identified five major issues and asked the agency to 

give these issues additional consideration: 

1. Additional consideration will be needed to adjust to the UCMR requirement to include 

monitoring of consecutive systems. 

2. EPA should set appropriate minimum reporting levels that reflect the level of potential health 

relevance as well as the limits of available analytical methods. 

3. EPA Method 537 (perfluorinated compounds) should be used in Assessment Monitoring and not 

in the Screening Survey.

4. EPA Method 539 (hormones) should be should be used in the Screening Survey and not in the 

Assessment Monitoring.

5. Given available methods and laboratory capacity, developing a Pre- Screening Testing Survey for 

algal toxins would be more likely to collect useful data than the proposed ground water monitoring 

using qRT-PCR-based testing. 

In reviewing the proposed rule, it is not clear that the agency understood all of our comments 

regarding these five issues. We appreciate those aspects of the proposal that reflect consideration of 

AWWA’s concerns, such as inclusion of representative sampling for consecutive systems. In our 
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responses to the agency’s requests for comment, we will detail outstanding concerns (some new and

some repeats) as yet unaddressed by the proposed UCMR3. 

Response: The proposal does reflect some of the items AWWA mentioned. For example, (1) 

UCMR 3 Assessment Monitoring and Screening Survey will be conducted at consecutive systems; 

(3) EPA Method 537 is specified for PFCs under UCMR 3 Assessment Monitoring; and, (4) 

hormones have been moved to the Screening Survey portion of UCMR 3, mitigating concerns 

regarding laboratory capacity. EPA agrees that the development of occurrence data on algal toxins is 

important, however, at this time, there is no appropriate analytical method available for those 

analyses.
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Comment Code: 20000 Sampling Design and Reporting

Summary Response to Comments on Sampling Design and Reporting: A PWS has the 

opportunity to change its sampling schedule established by EPA. Following publication of the final 

regulation, and until October 1, 2012, a PWS can independently revise its schedule using the EPA 

electronic data reporting system. After October 1, 2012, a PWS may request (subject to EPA review) 

that its schedule be changed; however, the PWS must explain its rationale for the requested change. 

Budgetary issues or well closings are examples of problems that will be considered legitimate reasons 

for schedule changes. A system is subject to its original assigned sampling schedule (or its modified 

schedule established by October 1, 2012) unless/until it receives a letter from EPA specifying a new 

schedule. 

Individual Comments

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority

Letter ID: 0062

Comment ID: 31654

Comment Code: 20000

Comment: Representative Samples

In addition, because our system is operated off a main transmission system, most communities have 

multiple takeoffs from the MWRA lines, meaning they have multiple entry points. However, the 

water is the same at each of these points and it is merely by reason of convenience and hydraulic 

efficiency that the meters were placed in this manner. MWRA supports EPA’s proposal to allow 

identification of a single entry point as representative, but requests that EPA retain flexibility to 

account for where samples can be practically taken; not every take-off point is easily sampled. 

Response: In the final rule language, EPA has clarified in §141.40(a)(3) Table 1, footnote c, by 

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. 

Commenter Name: Sandra Carey

Commenter Organization: International Molybdenum Association 

Letter ID: 0074

Comment ID: 31693

Comment Code: 20000

Comment: *With specific regard to the upcoming UMCR water sampling programme we submit 

the following comments for your consideration: 

- The proposed rule does not specify if sampling must be conducted during different seasons (i.e., 

winter and summer, for example). Because water quality can vary between summer and winter due 
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to variability in stream dilution flow in systems that obtain their water from surface water bodies or 

from groundwater under the direct influence of surface water, it would be optimal to sample during 

summer and winter to capture any variance in data.

Response: UCMR 3 specifies at 141.40(a)(4)(i)(B) Table 2 - Monitoring Frequency by Contaminant 

and Water Source Types that surface water systems must monitor for four consecutive quarters with 

sampling events 3 months apart; ground water systems must monitor twice in a 12 month period 

with sampling events 5-7 months apart. For the final rule, EPA has added an example to Table 2 

clarifying that if the first monitoring is in January, the second monitoring must occur any time in 

April, the third any time in July and the fourth any time in October. UCMR is designed as a national 

study with samples taken over all months and seasons, over three years, to have the potential to 

capture seasonal variability in contaminant occurrence.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31778

Comment Code: 20000

Comment: 11. Sampling points based on location availability - sampling points within a system may 

have different schedules

AMWA supports the ability for systems to notify EPA to reschedule sampling in the event that the 

sampling location is not available.

Response: Please see response to comment code 20000 Sampling Design and Reporting. 

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31811

Comment Code: 20000

Comment: The Minnesota Department of Health (MDH) expects difficulties in the proper 

identification of entry points and distribution system maximum residence time (DSMRT) locations, 

especially at purchasing (consecutive) PWSs (141.40(a)(4)(i) (C)). Furthermore, monitoring schedules 

may require revision based on scheduled and unscheduled distribution system flushing and 

maintenance activities.

Response: UCMR 3 samples will be collected at entry points to the distribution system (EPTDSs). 

In addition, UCMR 3 requires systems to collect the samples for total chromium, chromium-6, 

cobalt, molybdenum, strontium, vanadium, and chlorate at their distribution system maximum 

residence time (DSMRT) location(s) (specified in §§141.40(a)(3) Table 1, footnote c and 

141.40(a)(4)(i)(C)). EPA 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-
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Products Rule should use their total trihalomethanes (TTHM) highest concentration sampling site(s) 

as their DSMRT sampling site(s).

PWSs may perform sampling at representative sampling locations in two cases: (1) By demonstrating 

representative ground water sampling locations, where 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 (as specified in §141.35(c)(3)). An 

alternative location must be sampled if the representative EPTDS is not available at the time of 

scheduled sampling. The final rule establishes a deadline of August 1, 2012 for submission of new 

proposals or updates to existing plans. (2) By specifying representative intakes from a 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. 

EPA is available to advise PWSs regarding choosing the most appropriate sampling sites. 

Please see response to comment code 20000 Sampling Design and Reporting regarding changes in 

sampling schedules. 

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31827

Comment Code: 20000

Comment: Sample timing

The UCMR 3 sampling will occur during 2013 through 2015. This is the same time period during 

which PWSs that own surface water treatment plants will be required to perform their second round 

of raw water sampling under the Long Term 2 Enhanced Surface Water Treatment Rule (LT2). 

Both sampling events will be expensive.

The TCEQ recommends that the EPA take into account a system's LT2 sampling when scheduling 

the UCMR3 sampling in order to minimize the economic impact to PWSs. 

Response: EPA allows for alterations in the sampling schedule to allow for large PWSs to budget 

for the sampling and analysis. Please see response to comment code 20000 Sampling Design and 

Reporting regarding changes in sampling schedules. 
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Comment Code: 21000 Assessment Monitoring

Individual Comments

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31829

Comment Code: 21000

Comment: Sample point availability

Under 40 CFR 141.40(a)(4)(i)(B), the EPA has incorporated clarifying revisions to specify that large 

system monitoring schedules must be adjusted based on sample point availability. Should a location 

go off-line, an alternative location must be sampled. The PWSs would choose a sampling location 

from among the higher annual volume EP connections. If the connection selected as the 

representative EP was not available for sampling, an alternate representative connection would need 

to be sampled. 

The TCEQ comments that a better way to determine the scientific presence of contaminants in 

source water would be to monitor the source water itself. While the EP sampling does allow a broad 

overview of what current customers are exposed to, it fails to scientifically identify the actual sources 

that might be contributing to a potential contamination. The fact that this provision is needed 

demonstrates the issues of track ability with EP sampling in general.

Response: The UCMR design was established in fulfillment of the 1996 Amendments to the Safe 

Drinking Water Act (SDWA) (Section 1445(a)(2)(A)), which states: "The regulations shall require 

monitoring of drinking water supplied by public water systems..." The UCMR program was designed 

to collect data that would provide information for human exposure study. 
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Comment Code: 22000 Pre-Screen Testing

Summary Response to Comments on Pre-Screen Testing: UCMR 1 established the option of 

Pre-Screen Testing for List 3 contaminants to address contaminants with analytical methods that are 

in an early stage of development. The expectation was that it would be used at a limited number of 

systems determined to be most vulnerable to the targeted contaminants. If EPA finds any 

substantial frequency of occurrence of Pre-Screen Testing contaminants, these contaminants could 

become part of either the Screening Survey or part of Assessment Monitoring in future UCMR 

monitoring, or the results could be used in determining the need for future regulation. 

Monitoring will be conducted at the entry point to the distribution system. EPA will conduct PreScreen Testing for enterovirus and norovirus and related pathogen indicators at targeted 

undisinfected ground water systems that serve 1,000 or fewer customers. These undisinfected PWSs 

are located in sensitive hydrogeological areas, and will include 800 community, non-community, and 

non-transient non-community water systems. EPA will collect the samples from Pre-Screen testing 

locations, and will pay for all sampling and analysis costs associated with virus and indicator 

monitoring at these small systems.

The objectives of this monitoring are: (1) To obtain occurrence information to support regulatory 

determinations for enterovirus and norovirus; (2) to gain a better understanding of pathogen 

indicator and viral co-occurrence; and, (3) to gain more exposure/health risk information on viruses 

and indicators. While 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. The results will provide an 

understanding of the exposure risks in populations served by over 15,000 such as undisinfected 

systems in karst aquifers, by assessing the potential contamination of these aquifers to virus 

contamination. 

States (or EPA Regions, where states have opted not to participate) will receive a list of the PWSs 

selected to participate in the Pre-Screen Testing for review and comment. Through this process, 

State and local staff will be consulted to determine if selected systems meet the criteria for this 

testing (including whether an appropriate water tap is available for the large volume sampling).

Systems participating in List 3 monitoring will be required to allow EPA to monitor for enterovirus 

and norovirus and collect specified pathogen indicators. Please see section 141.40(a)(2)(ii)(C) and 

141.40(a)(3) for more information. Please see also response to comment code 37000 Viruses. 

Individual Comments

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31816

Comment Code: 22000
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Comment: The MDH supports the inclusion of transient noncommunity PWSs in the UCMR 3 

Pre- Screen Testing under List 3. That said, from our experience this can be a challenging PWS 

category with which to establish communications. In addition, site conditions can be extremely 

variable and may not allow standard sampling protocols, e.g., when a large sample volume or source 

water tap collection is required. A particular site may lack a sample tap for this type of discharge,

resulting in the need to collect the sample from within premise plumbing. Therefore, we recommend 

contacting State and local program staff at the time of PWS selection to determine site-specific 

conditions. The MDH is willing to assist with or collect these water samples. However, we request 

EPA clarify whether seasonal transient noncommunity PWSs will be selected for this sampling

effort.

The EPA has identified three Pre-Screen (List 3) Testing objectives. obtain occurrence data to 

support regulatory determination for enterovirus and norovirus; gain a better understanding of 

pathogen indicator and viral co- occurrence; gather more exposure and health risk information for 

viruses and indicators. Without looking beyond sensitive geologic setting (karst and fractured 

bedrock), we are very concerned how this data will be used to support the first objective of 

regulatory determination for viruses. In the 1970’s Minnesota looked at the microbial water quality 

in karst geology and not surprising found this geologic setting to be at risk. That study resulted in 

Minnesota placing special well construction criteria where karst may be used a drinking water source. 

Regarding the third objective, how is the source water data going to be used to gain exposure and 

health risk information for viruses? Without surveying the affected population it seems source water 

data alone will not be sufficient to satisfy this objective. 

In addition, we are concerned about whether the Pre-Screen (List 3) Testing will be used to 

determine if assessment monitoring will be conducted. From the Federal Register notice it was not

clear how the results will be used in future UCMR monitoring.

We do not agree with the statement used by U.S. EPA concerning vulnerability of small ground 

water systems and suggest the Agency consider modifying the following statement as a rationale for 

site selection. "The monitoring is proposed for systems that serve 1,000 or fewer customers because 

these smaller systems are the least likely to be disinfected, and therefore would be most vulnerable to 

contamination with viruses." Geologic sensitivity and well construction will determine whether a 

ground water source is vulnerable or at increased risk to microbial contamination, not the lack of 

disinfection. We are assuming the monitoring will be happening at the source and not within the 

distribution system.

Response: Please see response to comment code 22000 Pre-Screen Testing. It is probable that 

seasonal transient noncommunity systems may be selected for virus sampling. However, upon 

contacting the PWS if collecting two samples over six months is impossible, EPA will replace those 

systems.

EPA recognizes that the design of the virus monitoring portion of UCMR 3 samples only very small 

ground water systems, both transient and non-transient, that do not represent the totality of ground 

water systems. However, since these represent the most vulnerable systems, these data will provide 

EPA with the information it needs to determine if further regulation of these highly vulnerable 

systems is necessary.
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None of the water being monitored for viruses is treated prior to distribution. Therefore, this 

"source" water is the same water that is being distributed to the consumer.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31882

Comment Code: 22000

Other EPA Comment Codes and Descriptions: 37050 Borchardt Data - Viruses

Comment: Page 11719: "EPA welcomes comments on the Borchardt data and on the merits of the 

proposed UCMR 3 monitoring." 

We believe it is critical that EPA work to verify the implications of the Borchardt study whether 

through UCMR3 or by other means. If traditional surrogate indicators of viral contamination cannot 

be relied upon, it calls into question the presumptions in the Ground Water Rule and, in that case, 

the implications for ground water systems are significant. (However, while most states supported 

including viruses in UCMR3, at least one state questioned the value of including them, due to 

questions about their health significance in the drinking water context.) Conducting virus monitoring 

on a routine basis for compliance with a rule is not, in our judgment, a feasible option for small 

ground water systems at this juncture. EPA needs to have a valid scientific basis for any changes in 

the regulation of viruses. In conducting monitoring under UCMR3, the target group is small 

systems. Monitoring for viruses only at systems with a population of less than 1,000 could be 

construed to imply that undisinfected groundwater systems serving over 1,000 are not at risk. There 

are many systems over this population threshold that don’t disinfect and could be equally vulnerable. 

Under the proposed monitoring regime for UCMR3, we won’t know how many larger systems, both 

the undisinfected, and even those that disinfect, have viruses in their drinking water. We recommend 

that EPA expand its monitoring for these viruses to include, in the potential sample pool, any 

systems that meet the undisinfected ground water criteria, regardless of size. Another complication 

with the List 3 Pre-Screen Testing is the geologic setting of the systems to be sampled. The 

discussion regarding the viruses indicates that they are proposed to be monitored for in 

undisinfected PWSs located in sensitive hydrogeological areas. This is much like the UCMR1 where 

states were to indicate which systems were most vulnerable. In this proposal, there is no indication 

of how these systems are to be identified. States do not necessarily have the resources to determine 

which systems are most vulnerable, and may not want to be responsible for choosing such systems. 

Response: EPA will take the lead in identifying the vulnerable systems and coordinate with 

partnering states to review preliminary selections.

To maintain a manageable sample size (800 systems) EPA is restricting the virus study to the most 

vulnerable systems, those very small systems serving less than 1,000 customers, that are located in an 

area of vulnerable geology and that do not disinfect. Please see response to comment code 22000 

Pre-Screen Testing.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA
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Letter ID: 0066

Comment ID: 31884

Comment Code: 22000

Comment: Page 11722: EPA requests comments regarding the inclusion of transient systems in 

UCMR 3 Pre-Screen Testing.

The inclusion of transient systems does greatly expand the sample pool for acute contaminants like 

viruses that will be a health concern in these types of systems. Also, in some states a significant 

percentage of these systems are not disinfected and will be especially susceptible to virus 

contamination if viruses are in their source water. However, including this group is not without 

problems. These are often the poorest quality water systems in terms of construction, operation, and 

other factors that may prevent them from being good locations for sampling that can be used 

statistically to provide a national picture of contaminant occurrence. States should be consulted on 

the list of systems selected for UCMR monitoring and allowed to recommend dropping systems 

where local conditions would interfere with getting truly representative samples.

Response: Please see response to comment code 22000 Pre-Screen Testing.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31890

Comment Code: 22000

Comment: The USEPA should also consider conducting Pre-Screen Testing on small, community 

water systems that do not disinfect instead of including transient water systems. The community 

water systems may provide more meaningful data as some of the transient water systems serve a 

minimal population and/or may be seasonal, and the results of the monitoring may be difficult to 

interpret and extrapolate to community water systems.

Attached are additional technical comments on the Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR3) for Public Water Supplies. We appreciate the opportunity to 

provide comments on this important USEPA rule. If you have any questions or require additional 

information, please contact Sandra Krietzman of Water Supply Operations at 

sandy.krietzman@dep.state.nj.us or Dr. Gloria Post of the Office of Science at 

gloria.post@dep.state.nj.us.

Sincerely,

Gary A. Buchanan, Ph.D., Manager Office of Science

Karen Fell, Assistant Director Water Supply Operations Division of Water Supply 

C: Irene Kropp, NJDEP 

John Plonski, NJDEP 

Fred Sickels, NJDEP

Sandra Krietzman,NJDEP

Judy Louis, NJDEP 

Tom Atherholt, NJDEP
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Lee Lippincott, NJDEP

Stuart Nagourney, NJDEP

Gloria Post, NJDEP

Bernie Wilk, NJDEP

Response: EPA will be monitoring both community and non-community ground water systems. 

Please see response to comment code 22000 Pre-Screen Testing.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31914

Comment Code: 22000

Comment: The UCMR3 should target wells in "non-vulnerable" and "semi-vulnerable" formations, 

in addition to "vulnerable" formations for microbiological monitoring. Such formations include 

wells located in igneous and metamorphic rock and wells located in the coastal plain or similar 

unconsolidated lithologies. Wells located in all major types of lithologies in the US should be 

selected, but only those wells that can be thoroughly characterized beforehand. Such 

characterization should include the availability of substantial water quality data and well permit and 

drilling record information. In addition, an on-site inspection of each well should be conducted by 

qualified personnel prior to the selection process to eliminate any wells with construction defects. 

There is an additional consideration. Many small systems without disinfection have holding tanks 

prior to an access tap. Typically, these holding tanks are in place when parameters such as pH or 

hardness need to be corrected. To get a "true" picture of groundwater quality, wells must be selected 

that either do not have holding tanks or that have access taps prior to holding tanks. 

Response: While EPA agrees that an on-site inspection of wells to determine potential construction 

defects would be a useful addition, it is beyond the scope and capabilities of a UCMR national 

occurrence study. Although proposed virus monitoring under proposed UCMR 3 may be focused 

on a small percent of national population, it still gives an understanding of the exposure risks in 

populations served by over 15,000 undisinfected systems in karst aquifers nationally, by assessing the 

potential contamination of these aquifers to virus contamination. This is best determined at the well 

itself. Data collected under the UCMR 3 will be used to inform whether additional data gathering 

and/or future regulation may be needed for enterovirus or norovirus in untreated ground water.

To maintain a manageable sample size (800 systems) EPA is restricting the virus study to the most 

vulnerable systems, those very small systems serving less than 1,000 customers, that are located in an 

area of vulnerable geology and that do not disinfect. 

The primary purpose of the virus monitoring portion of UCMR 3 is to determine if the systems that 

are located in the most vulnerable geographic locations are indeed vulnerable to virus 

contamination. The presence of holding tanks does not impact this determination of ground water 

vulnerability.
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Comment Code: 23000 Other Changes between UCMR 2 and UCMR 3

Summary Response to Comments on Other Changes between UCMR 2 and UCMR 3: The 

date for determining UCMR 3 applicability is December 31, 2010, as specified in 141.40(a). The 

applicability date establishes which PWSs must monitor and is independent of the drinking water 

source or changes in drinking water sources that may occur during the UCMR 3 monitoring period. 

As specified in Section 141.40 (a)(4)(i)(B), Table 2 of UCMR 3, "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)". 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. For the final rule, EPA has moved the hormone monitoring requirement from 

Assessment Monitoring (List 1) to Screening Survey (List 2). This change will substantially reduce 

the number of PWSs that are required to monitor for hormones and mitigate any concerns regarding 

laboratory capacity. The Screening Survey will be conducted by all community and non-transient, 

non-community water systems serving more than 100,000 people, 320 randomly selected systems 

serving 10,001 to 100,000 people, and 480 randomly selected systems serving 10,000 or fewer 

people. Transient non-community water systems are excluded from Assessment Monitoring and 

Screening Survey. 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 are subject to UCMR 3 (as 

indicated by Federal Safe Drinking Water Information System (SDWIS/Fed) on December 31, 

2010).

Individual Comments

Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31718

Comment Code: 23000

Comment: Hi, Please find attached comments on the proposed Unregulated Contaminant 

Monitoring Regulation (UCMR 3).

Please contact me if you have any questions.

Thanks, Steve

Steve Bigley Environmental Services Manager Coachella Valley Water District Post Office Box 1058

Coachella, California 92236 Phone: (760) 398-2661, ext. 2286 Mobile: (760) 393-7792 Email: 

sbigley@cvwd.org
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File: 0551.1111 Water Docket U.S. Environmental Protection Agency, Mail Code 2822 lIT 1200 

Pennsylvania Avenue, NW., Washington, DC 20460 Attention: Docket ID No. OW-2009-0090

Email: ow-docket@epa.gov

Dear Mr. David Munch:

Subject: Draft Unregulated Contaminant Monitoring Regulation (OW-2009-0090)

We appreciate the opportunity to provide comments on the draft third installation of the 

Unregulated Contaminant Monitoring Regulation (UCMR3). Coachella Valley Water District 

(CVWD) provides domestic water, wastewater, recycled water, irrigation/drainage and regional 

storm water protection services to a population of 265,000 throughout the Coachella Valley. 

Your consideration of the following comments is appreciated:

1. Drinking Water Source Applicability. CVWD agrees with using a water systems’ retail population 

served as of December 31, 2010, to determine which water systems are subject to UCMR3 

monitoring. However, the proposed UCMR3 fails to specify a date of applicability for determining 

which drinking water sources are subject to UCMR3 monitoring. This was a key determination for 

UCMR2 (second UCMR) that is missing in the proposed UCMR3. The proposed UCMR3 should 

also specify December 31, 2010, as the applicable date to identify PWS drinking water sources 

subject to UCMR3. Water agencies need this specificity and certainty to prepare monitoring plans 

and schedule work needed to comply with UCMR3. 

Response: Please see response to comment code 23000 Other Changes between UCMR 2 and 

UCMR 3.

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31760

Comment Code: 23000

Comment: Please see the attached letter from Robert A. Hollander, President, WESTCAS, 

regarding Docket ID OW-2009-0090. Thank you for your attention to and consideration of these 

comments.

April 29, 2011 Water Docket U.S. Environmental Protection Agency, Mail Code 282211T 1200 

Pennsylvania Avenue, NW., Washington, DC 20460 Attention: Docket ID No. OW-2009-0090 To 

Whom It May Concern: Subject: Proposed Revisions to the third Unregulated Contaminant 

Monitoring Regulation (UCMR3) for Public Water Systems

WESTCAS is a coalition of approximately 125 water and wastewater districts, cities, towns, and 

professional organizations focused on water quality and water quantity issues in the States of 

Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, and Texas. Our mission is to 

work with Federal, State, and Regional water quality and quantity agencies to promote scientifically-
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sound laws, regulations, appropriations, and policies that protect public health and the environment 

in the arid West. 

The Western Coalition of Arid States (WESTCAS) is pleased to provide the following comments on 

the proposed UCMR3 for Public Water Systems (PWS): 

1. Drinking Water Source Applicability. WESTCAS agrees with using a water systems’ retail 

population served as of December 31, 2010, to determine which water systems are subject to 

UCMR3 monitoring. However, the proposed UCMR3 fails to specify a date of applicability for 

determining which drinking water sources are subject to UCMR3 monitoring. This was a key 

determination for UCMR2 (second UCMR) that is missing in the proposed UCMR3. The proposed 

UCMR3 should also specify December 31, 2010, as the applicable date to identify PWS drinking 

water sources subject to UCMR3. Water agencies need this specificity and certainty to prepare 

monitoring plans and schedule work needed to comply with UCMR3. 

Response: Please see response to comment code 23000 Other Changes between UCMR 2 and 

UCMR 3.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31843

Comment Code: 23000

Comment: Dear Sir/Madame, Attached are comments from the Orange County Water District on 

EPA’s Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public 

Water Systems published in the Federal Register on March 3, 2011. If you have any questions, please 

do not hesitate to contact me at (714) 378-3281

Thank you, Nira Yamachika Director of Water Quality Orange County Water District

April 28, 2011 Water Docket U.S. Environmental Protection Agency, Mail Code 282211T 1200 

Pennsylvania Avenue, NW., Washington, DC 20460 Attention : Docket 10 No. OW-2009-0090 Re: 

Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public Water 

Systems

Dear Madam/Sir:

The Orange County Water District (OCWD) is an agency formed by the State of California in 1933 

to protect and manage the Orange County groundwater basin. The OCWD is located in a highly 

urbanized area of northern Orange County. There are over 20 water utilities within our basin serving 

a population of over 2.3 million people. Over 225 drinking water wells are within our basin, which

provide approximately 65-70 percent of the drinking water. Imported treated surface water 

(purchased water from a wholesaler) from northern California and the Colorado River supplies the 

remainder. On behalf of our Groundwater Producers, OCWD assumes all monitoring, analytical and 

reporting responsibilities to comply with state and federal drinking water regulations for 
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groundwater sources. Analyses are performed at OCWD's new state certified Advanced Quality 

Assurance Laboratory located on-site.

OCWD has been actively involved with the Environmental Protection Agency's (EPA) Unregulated 

Contaminant Monitoring Regulations (UCMR1 and UCMR2), including all components required for 

successful monitoring, analysis, and reporting of data to EPA. On behalf of our Groundwater 

Producers, OCWD has assumed responsibility with all tasks associated with the UCMR program, as 

summarized below: 

* Developing groundwater and imported treated surface water (purchased at wholesaler 

connections) monitoring plans 

* Meeting with EPA Region 9 and obtaining approval for the UCMR2 groundwater (all groundwater 

wells sampled , not representative wells) and imported surface water source (representative 

connections) monitoring plans 

Entering source inventory information into SDWARS for each sampling point, both groundwater 

and treated surface water locations; updating SDWARS with appropriate sample notes with each 

sampling event 

* Developing, coordinating, and implementing source water sampling with each water utility

* Conducting all required field sampling and submitting samples to OCWD’s UCMR approved 

laboratory for all List 1 and List 2 analytes

* Reviewing and approving laboratory posted data in SDWARS 

* Contacting the EPA Sampling Coordinator to add or revise PWSs source for monitoring 

* Contacting EPA Region 9 for system specific issues and responding to their inquiries 

OCWD reviewed the EPA’s Proposed Revisions to the UCMR3 for Public Water Systems published 

in the Federal Register on March 3, 2011 and as described above, has many years of experience, 

both from a field and laboratory perspective to provide comments on several proposed revisions. 

We appreciate the opportunity to review the proposed UCMR3 document and provide the following 

comments for your consideration in finalizing the regulation. 

1.0 Applicability Date and Drinking Water Sources: Inclusion in Regulatory Language 

The UCMR3 monitoring will be required by community and non-transient noncommunity public 

water systems (PWSs) serving more than 10,000 people (retail population) and a nationally 

representative sample of small systems (to be funded by EPA). The determination of retail 

population is defined as the population reported in the Safe Drinking Water Information System 

(SDWIS) /Federal database as of December 31, 2010 (i.e., date used to determine which systems are 

subject to UCMR3 monitoring). Defining the type of system (e.g., community, etc.) and populationbased applicability date (FR, pages 11721, 141.35(a) and 141.40(a)) identifies the regulated entities 

covered by the regulation but does not specify the "drinking water sources" applicable to the 

UCMR3 monitoring requirements. The second cycle of UCMR (UCMR2) clearly listed the 
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applicable date to determine sources required for monitoring (FR January 4, 2007, preamble, page 

371):

"This final regulation also specifies the PWS system’s water sources and population served, as of 

June 30, 2005, as the basis for establishing a defined list of PWSs that are subject to the rule 

requirements." UCMR3 should also specify December 31, 2010 as the applicable date to identify 

PWSs drinking water sources (coincide with applicable date for retail population served) subject to

monitoring requirements and included in the regulatory language. Specifying the applicable date to 

identify drinking water sources (data element #4, sample point identification code in EPA’s UCMR 

electronic data reporting system) allows water systems to prepare monitoring plans, coordinate with 

contract laboratory capacity, project monitoring costs, and avoids potential revisions in the UCMR3 

Safe Drinking Water Accession and Review System (SDWARS) source water inventory database 

throughout the three year monitoring period (i.e., must notify the EPA UCMR Sampling 

Coordinator to add a new source that comes on-line after the water system has completed their 12 

consecutive month scheduled monitoring, enter new source information into SDWARS, coordinate 

and schedule with laboratory for additional source testing, and coordinate and schedule with 

sampling personnel to conduct monitoring). 

Response: Please see response to comment code 23000 Other Changes between UCMR 2 and 

UCMR 3.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31875

Comment Code: 23000

Comment: May 2, 2011

Water Docket U.S. Environmental Protection Agency, Mail Code 282211T 1200 Pennsylvania 

Avenue, NW., Washington, DC 20460 Attention: Docket ID No. OW-2009-0090

Re: Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public Water 

Systems (EPA-HQ-OW-2009-0090-0001)

To Whom It May Concern: 

The Association of California Water Agencies (ACWA) appreciates the opportunity to comment on 

the proposed revisions to the third Unregulated Contaminant Monitoring Regulation (UCMR3). 

ACWA represents nearly 450 public water agencies in California that collectively supply over 90% of 

the water delivered in California for domestic, agricultural and industrial uses. 

We appreciate the opportunity to review and comment on the proposed UCMR3 and provide the 

following comments for your consideration in finalizing the regulation. 

1.0 Applicability Date and Drinking Water Sources: Inclusion in Regulatory Language 
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The UCMR3 monitoring will be required by community and non-transient noncommunity public 

water systems (PWSs) serving more than 10,000 people (retail population) and a nationally 

representative sample of small systems (to be funded by EPA). The determination of retail 

population is defined as the population reported in the Safe Drinking Water Information System 

(SDWIS) /Federal database as of December 31, 2010 (i.e., date used to determine which systems are 

subject to UCMR3 monitoring). Defining the type of system (e.g., community, etc.) and populationbased applicability date (FR, pages 11721, 141.35(a) and 141.40(a)) identifies the regulated entities 

covered by the regulation but does not specify the "drinking water sources" applicable to the

UCMR3 monitoring requirements. The second cycle of UCMR (UCMR2) clearly listed the 

applicable date to determine sources required for monitoring (FR January 4, 2007, preamble, page 

371):

"This final regulation also specifies the PWS system’s water sources and population served, as of 

June 30, 2005, as the basis for establishing a defined list of PWSs that are subject to the rule 

requirements." 

UCMR3 should also specify December 31, 2010 as the applicable date to identify PWSs drinking 

water sources (coincide with applicable date for retail population served) subject to monitoring 

requirements and included in the regulatory language. Specifying the applicable date to identify 

drinking water sources (data element #4, sample point identification code in EPA’s UCMR 

electronic data reporting system) allows water systems to prepare monitoring plans, coordinate with 

contract laboratory capacity, project monitoring costs, and avoids potential revisions in the UCMR3 

Safe Drinking Water Accession and Review System (SDWARS) source water inventory database 

throughout the three year monitoring period (i.e., must notify the EPA UCMR Sampling 

Coordinator to add a new source that comes on-line after the water system has completed their 12 

consecutive month scheduled monitoring, enter new source information into SDWARS, coordinate 

and schedule with laboratory for additional source testing, and coordinate and schedule with 

sampling personnel to conduct monitoring). 

Response: Please see response to comment code 23000 Other Changes between UCMR 2 and 

UCMR 3.
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Comment Code: 23100 Transient Systems

Individual Comments

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31683

Comment Code: 23100

Comment: Page 11722

EPA requests comments regarding the inclusion of transient systems in UCMR 3 PreScreen Testing.

NMED Comment

In New Mexico, 36 percent of the active transient systems that serve fewer than 1,000 people do not 

provide disinfection, 154 of 427 systems. Although these systems serve less than 4 percent of the 

total population served by public water systems in New Mexico, there is an interest in occurrence of

enterovirus and norovirus in these systems, because these contaminants pose an acute health risk.

Response: EPA appreciates your comment and support for including transient systems in UCMR 3 

Pre-Screen Testing.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32096

Comment Code: 23100

Comment: 8. Inclusion of transient systems in UCMR 3 Pre-Screen Testing. AWWA does not 

support the inclusion of transient non-community water systems in the UCMR monitoring 

framework. These systems represent a substantial fraction of the number of regulated public water 

systems. The likelihood that inclusion of these systems will not add relevant information for 

regulatory decision-making is relatively low while the likelihood inclusion will reduce the quality of 

the resulting dataset is substantial:

1. EPA is not able to adequately fund transport and processing of a sufficient number of samples 

from these small systems to provide an informative dataset; consequently, a statistically valid sample 

is infeasible.

2. TNCWS seldom have trained operators and, as a consequence, are less likely to appropriately 

handle these samples.
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Response: EPA will be responsible for and will pay for the sampling, shipping and analyses of the 

samples for Pre-Screen Testing. EPA is confident that it has budgeted sufficient funds to support 

these activities.

Transient non-community systems represent a substantial percentage of the undisinfected ground 

water systems, and therefore, their inclusion is important. While 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. 

The results will provide an understanding of the exposure risks in populations served by over 15,000 

such undisinfected systems in karst aquifers nationally, by assessing the potential contamination of 

these aquifers to virus contamination. . 
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Comment Code: 23200 Retail Population Based Applicability

Summary Response to Comments on Retail Population Based Applicability: UCMR 3 

requires that Assessment Monitoring be conducted by all large community and non-transient, noncommunity water systems serving more than 10,000 people, and a nationally representative sample 

of 800 small water systems serving 10,000 or fewer people. In addition, for the final rule, EPA has 

moved the hormone monitoring requirement from Assessment Monitoring (List 1) to Screening 

Survey (List 2). This change will substantially reduce the number of PWSs that are required to 

monitor for hormones and mitigate any concerns regarding laboratory capacity. The Screening 

Survey (for List 2 contaminants) will be conducted by all community and non-transient, noncommunity water systems serving more than 100,000 people, 320 randomly selected systems serving 

10,001 to 100,000 people, and 480 randomly selected systems serving 10,000 or fewer people (based 

on retail population as indicated by SDWIS/Fed on December 31, 2010). Transient non-community 

water systems are excluded from Assessment Monitoring and the Screening Survey. Unlike UCMR 1 

and 2, those systems that purchase all of their finished water from another system are not excluded 

from the requirements of UCMR 3. The population definitions used for the previous UCMRs 

created an inconsistency for PWSs purchasing their water (for example, if a PWS purchased all of 

their water, they were not required to monitor at all, and systems that had no retail connections did 

have to monitor). If a PWS purchased some of their water, they were required to monitor from their 

own sources, as well as their purchased source. The new proposed definition was designed to 

eliminate this inconsistency. 

In addition, this change should greatly improve exposure estimates, since exposure estimates will be 

based on the monitoring data collected from where the water is consumed rather than where it is 

sold. Between the wholesaler and purchasing system, contaminant levels may increase (e.g., DBPs or 

metals) or decrease (e.g., through blending various sources or degradation/chemical reactions). 

Because the retail population comprises all of the people exposed to water from a particular system, 

EPA will have a clearer understanding of the number of people exposed to a detected contaminant. 

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 fewer 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. EPA notes that approximately 450 wholesale systems will no longer 

be subject to monitoring; the net increase is approximately 800 systems.

While EPA is aware that this will require PWSs that previously were exempt from monitoring to 

now monitor, and in some cases this will result in the same wholesale water to be monitored by 

more than one PWS, EPA believes that the benefits conferred by this change justify the approach. 

Based on the experience of UCMR 1 and UCMR 2, EPA believes it is more appropriate to measure 

at each purchasing system to more accurately assess exposure. This approach relies on each 

purchasing system to monitor, thus ensuring the monitoring results reflect any potential water 

quality changes between the wholesaler and each purchasing system. To mitigate the burden, 

systems that purchase water with multiple connections from the same wholesaler are permitted to 

sample from one representative connection from that wholesaler.

Individual Comments
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Commenter Name: Anonymous 

Commenter Organization:

Letter ID: 0041

Comment ID: 31602

Comment Code: 23200

Comment: It is ridiculous to require agencies that purchase all of their water from other agencies to 

monitor for contaminants that have already been sampled, as required, by the suppliers. Simply put, 

a waste of time and resources.

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

Commenter Name: Dennis O'Sullivan

Commenter Organization: DoD Safe Drinking Water Act Services Steering Committee

Letter ID: 0048

Comment ID: 31615

Comment Code: 23200

Comment: Page # (FR Notice/ Method): FR: 11721 Para#/ Line# (Methods documents): Section 

III.E.1.; par.2, line 1 Comment Classification C/M/S/A: S

Comment: Requiring systems that purchase their water to conduct monitoring/sampling imposes 

an undue burden on the PWS. 

Rationale: These systems would now be subject to UCMR monitoring requirements. Generally, 

consecutive water systems do not have control over the quality of water provided.Recommend that 

EPA or the party responsible for distribution be required to conduct distribution system monitoring, 

not the PWS that purchases the water. Alternately recommend that the proposed monitoring 

requirement for PWSs that purchase their water be removed altogether.

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

Commenter Name: David Chang 

Commenter Organization: Golden State Water Company (GSWC)

Letter ID: 0054

Comment ID: 31630

Comment Code: 23200

Comment: * GSWC is in support of the provision that each PWS use only its own retail population 

to determine if the system falls under the monitoring requirements. 

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

Commenter Name: Phillip W. Holderness 
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Commenter Organization: California-Nevada Section, American Water Works Association (CANV AWWA)

Letter ID: 0055

Comment ID: 31636

Comment Code: 23200

Comment: * CA-NV AWWA is in support of the provision that each PWS use only its own retail 

population to determine if the system falls under the monitoring requirements. 

Response: Please see response to comment code 23200 Retail Population Based Applicability.

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority

Letter ID: 0062

Comment ID: 31653

Comment Code: 23200

Comment: May 2, 2011 Water Docket United States Environmental Protection Agency Mail Code 

282211T 1200 Pennsylvania Avenue, N.W. Washington, DC 20460

Sent via web application

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

Water Systems, Docket ID No. OW-2009-0090

Dear Sir or Madam:

The Massachusetts Water Resources Authority (MWRA) is an independent authority providing 

wholesale water and wastewater service to approximately 2.5 million people in 61 cities and towns 

primarily in the Boston metropolitan area. MWRA provides water service from the well-protected 

Quabbin and Wachusett Reservoirs in central Massachusetts and is nearing completion of a 10-year 

1.7 billion dollar integrated water supply improvement program which includes continued aggressive 

watershed protection, a new water treatment plant using ozone and chloramines, a 17-mile long, 14-

foot diameter new transmission tunnel for supply redundancy, replacement of open distribution 

reservoirs with covered storage and aggressive pipeline rehabilitation in both the MWRA system and 

our member community systems. Investments in our water and wastewater infrastructure over the 

25 years since MWRA was created total over 6 billion dollars. We and our member communities 

have a total of over 6000 miles of pipe in our distribution systems.

MWRA appreciates the opportunity to comment on the Unregulated Contaminant Monitoring 

Regulation (UCMR-3).

MWRA has participated in the development of and is aware of the content of comments from the 

American Water Works Association (AWWA) and the Association of Metropolitan Water Agencies 

(AMWA). We are generally supportive of their comments and urge that you carefully consider them. 

We provide specific comment on a few particular items below.
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Base UCMR Applicability on Retail Population 

While EPA’s proposal to base the applicability of UCMR-3 on retail population may serve to reduce 

some problems matching population with sample results which occurred in previous rounds, it 

introduces new ones. MWRA does not support the proposal as introduced, unless EPA clearly and 

explicitly provides for flexibility to accommodate specific circumstances where treating a regional

system as a single entity makes more sense.

MWRA is the sole provider of wholesale finished water to 29 communities in the metropolitan 

Boston area. All 29 receive water from the same sources, which is withdrawn at a single intake, 

treated at a single water treatment plant and travels through the same transmission system to their 

takeoff points. No further treatment occurs beyond the MWRA’s single treatment plant. Physically,

our system performs as a single system, and for most current drinking water regulations, the MWRA 

system is treated as a single entity as the water is the same regardless of where the political 

boundaries lie. These 29 communities serve about 1.6 million persons. 

For current drinking water rules, and for previous UCMRs, MWRA collected a single set of samples 

for the entire region, and attributed those samples to the entire regional population. No individual 

fully supplied community had to collect samples. Under this current proposal, 26 of the 29 

communities have populations over 10,000 and would be required to individually collect samples. 

These 26 communities have almost 99 percent of the population served by the 29 community 

region; the remaining 3 smaller systems serve only around 16,500 persons. 

As best we can determine, no additional useful information will be derived from taking 26 times as 

many samples at what will undoubtedly be at least 26 times the cost. We strongly urge EPA to either 

reconsider this change, or to explicitly provide the flexibility for this type of circumstance to be

efficiently and effectively be handled on a case by case basis.

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31686

Comment Code: 23200

Comment: Page 11716

In addition to requesting comment on the proposed list of contaminants, EPA also requests 

comment on monitoring based on retail population; revised data elements; and other changes 

between UCMR 2 and UCMR 3 that are outlined in Exhibit 2. Updates to Web addresses, 

applicability dates, corrections of minor typographical errors, and other minor clerical edits are

reflected in rule language, but do not appear in Exhibit 2. 

NMED Comments
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The discussion on page 11721, Section III.E.1, of the preamble provides clarity to the population 

considered under the rule. The annotation given in that section should be included in the rule. This 

would result in a change to the description in Section 141.35a. Section 141.35a would read 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, SDWISFed, i.e., wholesale or 

consecutive populations are not included. 

Response: The definition of "population served" has been revised as suggested. 

Commenter Name: Eddy So 

Commenter Organization: San Francisco Public Utilities Commission

Letter ID: 0082

Comment ID: 31703

Comment Code: 23200

Comment: Dear EPA Rulemaking Manager,

Thank you for the opportunity to comment on the proposed UCMR3. The San Francisco Public 

Utilities Commission (SFPUC) supplies drinking water to a total population of 2.5 million customers 

in the San Francisco Bay Area via 30 wholesale customers. We found the proposed UCMR3 is well 

written with useful highlights summarizing the changes to the previous UCMRs. We have some 

comments on the proposed regulation summarized below for your consideration. 

Change of Population Base to Determine Applicability We applaud the proposed change of 

population base to retail in determining the rule’s applicability to water systems, and support EPA’s 

reasons for the change. The new approach will not only eliminate inconsistencies and 

misunderstanding among wholesalers and retail systems, but also the data collected from this 

monitoring would be more meaningful for future contaminant exposure evaluation. However, many 

utilities have more than one turnout for the same supply, and do not have sampling taps at their 

turnouts. EPA should address these situations for the retail systems when point of entry (POE) 

monitoring is required. 

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

EPA expects that at least one turnout would have a tap. However, PWSs are encouraged to contact 

EPA to discuss an alternate sampling point if there is not a sampling tap at any turnout. The UCMR 

sampling coordinator can be reached at UCMR_Sampling_Coordinator@epa.gov. 

Commenter Name: Gregory E. DiLoreto

Commenter Organization: Tualatin Valley Water District (TVWD)

Letter ID: 0083

Comment ID: 31705

Comment Code: 23200

Comment: Attached are comments submitted on behalf of the Tualatin Valley Water District

regarding Docket # OW-2009-0090. Please contact me if you have any questions.
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Sincerely,

Todd Heidgerken Manager, Community and Intergovernmental Relations Tualatin Valley Water 

District 1850 SW 170th Avenue Beaverton, OR 97006 503-848-3013 fax: 503-356-3113

toddh@tvwd.org 

May 2, 2011

Water Docket United States Environmental Protection Agency Mail Code 282211 T 1200 

Pennsylvania Avenue, NW Washington, DC 20460 

Attention Docket ID No. OW-2009-0090

On behalf of Tualatin Valley Water District (TVWD), I respectfully submit the following comments 

for your consideration regarding proposed revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR 3) for Public Water Systems (Docket ID No. OW- 2009- 0090). As Oregon's 

second largest drinking water provider that serves more than 200,000 people in Washington County, 

providing our customers with quality water and customer service is our mission. 

TVWD is a large consecutive public water system with purchased water supplied from two separate 

systems. In addition, we have an aquifer storage and recovery (ASR) well and, as such, will 

presumably be subject to UCMR3 monitoring. However, we believe the following comments should 

be made based on TVWD's general concerns about the justification for consecutive system 

monitoring rather than direct impacts to TVWD.

TVWD would like to focus its comments on the changes between UCMR 2 and UCMR 3 as it 

relates to the monitoring being based on retail populations thus including consecutive public water 

systems that solely purchase water. TVWD generally does not support the need for UCMR 

monitoring by consecutive systems for the following reasons: 

*Consecutive system data provides little additional benefit. The primary objective of UCMR 

monitoring is to identify the occurrence of contaminants and the public's exposure to listed 

contaminants. Given that the water quality in the consecutive system is already characterized in the 

water supplier's systems, there is little if any additional benefit by sampling the same water again in

the consecutive system.

*Without true paired samples, consecutive system monitoring is not productive. Characterization of 

the occurrence of contaminants that may change over time (e.g., Dinsinfection By-Products (DBPs)) 

as water travels from one system to another requires significantly greater control over sampling 

schedules to assure that results from the source system and consecutive system are truly comparable. 

This is especially important and challenging for consecutive systems that may receive water from 

more than one system particularly since the consecutive system has no control over the sampling 

schedule of the supplying system(s). In the absence of such controls and sample scheduling, direct 

comparison of results between the systems is meaningless and potentially misleading. 

*Monitoring doubles the cost burden on consecutive systems. Consecutive systems will essentially 

be paying at least twice - once through rates for purchased water and again for the redundant 

monitoring within the consecutive system. This places a disproportionate financial burden on the 
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consecutive system - which is especially troublesome when you consider that the additional data 

doesn't change the conclusions of the occurrence monitoring under UCMR. 

TVWD acknowledges that there may be certain contaminants and/or conditions where monitoring 

by consecutive systems is appropriate, for example Chromium 6, nitrosamines and DBPs, where 

concentrations could be anticipated to change over time and/or where additional treatment is 

practiced by consecutive system that could change the resulting concentration of the target 

contaminant. Therefore, we encourage EPA to require UCMR monitoring by consecutive only for 

those contaminants where there is a documented need for the additional data - for example, nonconservative contaminants (such as DBPs) or where further treatment by the consecutive system 

may have an affect (such as nitrosamine levels resulting from chloramination). Further, in those 

limited cases where consecutive system monitoring is justified, such monitoring should be 

conducted with paired sampling to assure comparability of results between the supplying system and 

the consecutive system.

I thank you for your consideration of these comments submitted on behalf of TVWD.

Sincerely,

Gregory E. DiLoreto Chief Executive Officer

Response: Please see response to comment code 23200 Retail Population Based Applicability.

Commenter Name: Deborah H. Metz 

Commenter Organization: Greater Cincinnati Water Works (GCWW)

Letter ID: 0085

Comment ID: 31706

Comment Code: 23200

Comment: Dear Sir or Madam:

Greater Cincinnati Water Works appreciates the opportunity to comment on the Revisions to the 

UCMR 3 for public water systems. Attached are our comments. If you have any questions or need 

further information, please don’t hesitate to contact us. 

Sincerely, Ramesh Kashinkunti 

Ramesh D. Kashinkunti, P.E., BCEE Greater Cincinnati Water Works Water Quality and Treatment 

Division 5651 Kellogg Avenue Cincinnati, OH 45230

(513)624 5622 (P) (513) 624 5670 (F) Ramesh.Kashinkunti@gcww.cincinnati-oh.gov 

May 02,2011 Water Docket No. OW-2009-0090, Environmental Protection Agency Mail Code 

282211T 1200 Pennsylvania Ave., NW. Washington, DC 20460, RE: Revisions to the Unregulated 

Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems 

Dear Sir or Madam:
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Greater Cincinnati Water Works (GCWW) is a public drinking water system supplying water to 

more than 1.1 million people in the Greater Cincinnati Area. GCWW employs state-of-the-art 

treatment processes and is currently installing UV technology at its surface water treatment plant. 

GCWW appreciates the opportunity to comment on the Revisions to the Unregulated Contaminant 

Monitoring (UCMR 3) for Public Water Systems. It is our strong belief that open communication 

and sharing of expertise will best protect our customers' interests and ensure they receive a plentiful 

supply of the highest quality water and outstanding services in a financially responsible manner. 

With that spirit in mind following are our comments on the Revisions: 

1. Retail systems and now requiring consecutive systems to monitor 

a. While we appreciate the need for requiring consecutive systems to monitor for the UCMR list of 

contaminants, we don't believe having consecutive systems monitor for every contaminant is 

prudent. For example, contaminants such as hormones, estrogens, PFOA, etc., are found exclusively 

in source waters. For these contaminants monitoring by the producers at the plant effluent would be 

adequate, and we do not believe the expense and effort for the consecutive systems to monitor is 

worthwhile. 

b. Any treatment or subsequent treatment (e.g., different disinfectant) and chemical reaction 

transformation as a result of that treatment must be considered in interpreting the data. 

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

EPA has provided additional rationale for the agency’s approach to monitoring by wholesale and 

retail suppliers in the UCMR 3 preamble. Regarding the notion of selectively requiring consecutive 

systems to monitor for particular contaminants, EPA believes that there is enough potential for 

changes in concentrations of any of the contaminants to warrant monitoring for all of the 

contaminants by the consecutive systems.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31757

Comment Code: 23200

Comment: 20. An issue that has been important for both of the last 2 UCMRs and is even more 

relevant for UCMR3 is the case where multiple retailers receive water from the same wholesaler (and 

the interconnects are very close together or even the same). Under those conditions it is unnecessary 

to have multiple retailers collect and analyze separate samples, and there should be a way in the 

database to identify which retailer would sample. There should be a mechanism to facilitate 

reporting of the data such that the other retailer(s) do not get a Notice of Violation for failure to 

sample under these circumstances.

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)
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Letter ID: 0070

Comment ID: 31774

Comment Code: 23200

Comment: 8. Monitoring based on retail population, consecutive system (purchaser) proposes one 

representative connection for sampling, even if water is received from more than one wholesaler 

Addressing consecutive systems under the UCMR is an example of how one-size- fits-all regulations 

may not be the best fit for every circumstance. While some consecutive systems may purchase water 

and then add additional treatment, other regional water utilities may be the sole provider of all water 

and treatment for their wholesale customers. Therefore, AMWA recommends that the final UCMR

clearly and explicitly provide for flexibility to accommodate specific circumstances where treating a 

regional system as a single entity makes more sense.

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31820

Comment Code: 23200

Comment: Applicability

Population-based applicability and related applicability date

Under 40 CFR 141.35(a) and 141.40(a) the proposal would change how applicability is determined 

under UCMR 3 to base applicability on retail population. 

The TCEQ agrees with basing applicability on retail population, rather than on the entire wholesale 

population of a combined distribution system. The TCEQ notes that EPA direction regarding the 

applicability of rules to consecutive systems has been inconsistent, and recommends that the EPA 

consider the issue as part of any Distribution Rule pre-regulatory discussions. 

Required sampling at purchased-water systems

Under UCMR 1 and 2 (the first and second UCMR cycles), systems that purchased all of their water 

were not required to monitor. These systems would now be subject to UCMR 3 monitoring 

requirements. 

The TCEQ disagrees with sampling purchased water EPs for the organic contaminants listed in 

UCMR 3. The intent of sampling for the organic contaminants in the UCMR 3 list is to determine 

the contribution of source water contamination to drinking water. 

Therefore, the TCEQ agrees that it is logical to sample the entry point of a surface water treatment 

plant that may receive water from a stream that may contain pharmaceutical contaminants, in order 

to determine whether customers may be receiving those contaminants in their drinking water. 
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However, those contaminants, if present, are conservative; that is, they are neither created nor 

destroyed within the distribution system unlike disinfection byproducts or resuspended metals. 

Therefore, there is no reasonable scientific need to sample at distal transfer points, where a 

consecutive system purchases water for redistribution. No science suggests that there are significant 

contributions of these organic contaminants from distribution system sources, as there may be in the 

case of resuspension of metal contaminants from pipe tubercules. The cost of the sample analysis 

for the UCMR 3 organic contaminants is very significant. The TCEQ recommends that the EPA 

not require organic sampling at purchased water entry points. If the EPA does not retract this 

requirement, the TCEQ recommends that the EPA notify systems with purchased water entry 

points well in advance of their sampling, so that they can seek some flexibility from the EPA.

EPA provides that systems that purchase water with multiple connections from the same wholesaler 

would be permitted to propose one representative connection from that wholesaler. The EPA 

should include a corresponding provision that a sample taken from the provider's system can 

represent levels at all downstream systems.

The TCEQ agrees with sampling purchased water for the inorganic contaminants listed in UCMR 3, 

based on the premise that these contaminants could deposit, resuspend, or otherwise change 

concentration due to corrosivity and other distribution system factors.

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

While organic non-disinfectant byproducts may or may not be created or destroyed in the 

distribution system (certainly organic compounds are impacted by biofilms in distribution systems) 

the primary purpose of this change to substantially improve EPA's information on populations 

served. Currently, the complexity of consecutive systems is such that EPA cannot obtain accurate 

population estimates for PWSs with consecutive systems, which greatly impairs our assessments of 

the populations impacted by the occurrence of these contaminants. 

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31867

Comment Code: 23200

Comment: Monitoring based on retail population: ASDWA agrees this change makes the 

determination of the groups covered by the rule more straightforward and clean. Beyond the change 

in the definition specified in §141.35(a), we also recommend adding the annotation given in on page 

11721 (Section III.E.1) of the preamble. This would result in a change to the description in. 

§141.35(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), i.e., wholesale or consecutive populations are not included. ***. While this change 

helps clean up the administrative side, monitoring of consecutive systems can lead to overestimating 

the occurrence of contaminants. If a wholesale system serving 10,000 retail customers and one of its 

consecutive systems (also serving over 10,000) both monitor for a contaminant related to the source 

and unchanged in the distribution system, then any occurrence is counted twice. In this case there is 

only one source of contamination. Unless the contaminant is one that would be expected to change 
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in the distribution system, we recommend continuing to exempt systems that purchase all of their 

water from UCMR monitoring.

Response: EPA has revised the definition in 141.35(a) to read: "(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.***" 

Please see response to comment code 23200 Retail Population Based Applicability.

Currently, the complexity of consecutive systems is such that EPA cannot obtain accurate 

population estimates for PWSs with consecutive systems, which greatly impairs our assessments of 

the populations impacted by the occurrence of these contaminants. Making this change will greatly 

improve the quality of this critical population served data.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31889

Comment Code: 23200

Comment: The NJDEP also supports the use of retail population to determine which community 

water systems are required to participate in the Assessment Monitoring portion of the UCMR3; 

however, we request that wholesale and consecutive water systems not be included in Assessment 

Monitoring since their water will have already been tested at the treatment plant of the water seller. 

This could result in counting the occurrence of contaminants associated with the source of water 

twice (or more). If there are contaminants associated with the water distribution system that should 

be monitored by wholesale and consecutive systems, then this monitoring should still be considered 

in the final rule. 

Response: Please see response to comment code 23200 Retail Population Based Applicability. 

It is important that EPA obtain accurate population estimates for PWSs with consecutive systems, 

since this impacts our assessments of the populations impacted by the occurrence of these 

contaminants. Making this change will greatly improve the quality of this critical population served 

data.

Commenter Name: Yone Akagi

Commenter Organization: City of Portland, Oregon 

Letter ID: 0088

Comment ID: 31999

Comment Code: 23200

Comment: 2. EPA has proposed monitoring based on retail population as of 12/31/10 in SDWIS 

FED.

While Portland sees the benefit of population based monitoring as more consistent and stable, we 

have some concerns with the implementation proposed. As proposed, systems with no sources of 
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their own would be conducting entry point sampling. We believe this is inconsistent with other entry 

point sampling established in the drinking water regulations, which is done at the entry point for the 

source. In addition, this would likely substantially increase the number of systems that are required 

to monitor. These new systems would be systems that do not have a source of their own. 

Portland currently has two wholesale customers who have not been required to monitor under prior 

UCMR who would now be required to monitor. These systems serve only water provided to them 

by Portland Water Bureau. So, Portland’s water would be sampled three times as often. 

In addition to the extra cost these smaller systems would incur, the UCMR monitoring is technically 

more challenging for a water system with less experience performing source monitoring. 

Contaminants included in UCMR3 are measured at very low levels. Rigorous adherence to good 

sampling protocols will be essential in getting reliable results.

Response: Please see response to comment code 23200 Retail Population Based Applicability.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32037

Comment Code: 23200

Comment: 2. Expanding the number of water systems that will be required to monitor under 

UCMR by 30% (approximately 1,250 additional systems) through mandating community water 

systems serving greater than 10,000 persons that rely solely on purchased water participate when 

there is significant potential for addition, formation, or degradation of the target analyte within the 

combined distribution system. 

Response: EPA notes that approximately 450 wholesale systems will no longer be subject to 

monitoring; the net increase in water systems is approximately 800.

Please see response to comment code 23200 Retail Population Based Applicability.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32050

Comment Code: 23200

Other EPA Comment Codes and Descriptions: 23300 Ground Water Representative Monitoring 

Locations 

Comment: Monitoring Consecutive Systems in UCMR3 EPA does not specifically request

comment on whether consecutive systems should monitor under UCMR3. AWWA believes that this 

is one of the most important changes in the proposal over previous UCMR monitoring strategies. 

AWWA supports EPA’s decision to include consecutive systems in UCMR3 as a better means of 

characterizing contaminant occurrence when it is appropriate. Monitoring consecutive systems 
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should occur when there is significant potential for addition, formation, or degradation of the target 

analyte within the combined distribution system. 

AWWA is also concerned with the logistics of sampling consecutive systems. EPA’s proposed 

approach, one representative connection per wholesaler, is sound.[FN4:76 Federal Register 11721] 

AWWA agrees with EPA’s proposed approach to choosing a sampling location from among 

multiple wholesale connections, that is, selection of the higher annual volume entry-points-to-thedistribution- system (EPTDS) connections, and if the connection selected as the representative

EPTDS is not available for sampling, an alternate representative connection would need to be 

sampled.[FN5:76 Federal Register 11722] AWWA agrees that this approach should be captured in 

the rule’s regulatory language with some latitude for EPA to address system-specific considerations. 

AWWA suggests a similar strategy be employed with respect to distribution-system -maximumresidence-time (DSMRT) sample locations. The UCMR3 proposal recommends a populationweighted sampling strategy for DSMRT samples based on the Stage 2 Disinfectants and 

Disinfection Byproducts Rule (Stage 2 DBPR) sampling strategy. The situation is similar to instances 

where there are multiple wells and multiple EPTDSs that characterize the same source of supply. 

UCMR3 DSMRT samples, like EPTDS samples, could be focused on the selection of sites that 

reflect higher annual volume of distributed water. 

Response: Please see response to comment codes 23200 Retail Population Based Applicability and 

23300 Ground Water Representative Monitoring Locations. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32053

Comment Code: 23200

Comment: 2. EPA also requests comment on: monitoring based on retail population; revised data 

elements; and other changes between UCMR 2 and UCMR 3 (see Exhibit 2, 76 FR 11717).

AWWA supports UCMR monitoring being based on retail population when appropriate to 

characterize analyte occurrence. It is appropriate to include consecutive systems in UCMR 

monitoring when there is significant potential for addition, formation, or degradation of the target 

analyte within the combined distribution system. As noted previously, the most significant impact of 

this change is the addition to the UCMR sample of systems serving >10,000 population that rely 

solely on purchased water. Based on the most recent information from EPA’s Safe Drinking Water 

Information System (SDWIS), this action will add approximately 1,250 additional systems to the 

UCMR3 sampling pool.[FN9: 2010, EPA, Safe Drinking Water Information System Pivot Table 

(October 2010, Frozen)]

Based on the analytes identified in the UCMR3 proposal, it seems unlikely that these additional 

systems will substantially change the national characterization of occurrence in UCMR3. However, 

past experience with UCMR2 illustrates that there are some instances when this more complete 

sample would be very beneficial when characterizing national occurrence of analytes in the water 

reaching community water system’s customers (e.g., nitrosamines in UCMR2).
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Response: Please see response to comment code 23200 Retail Population Based Applicability. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32095

Comment Code: 23200

Comment: 7. Establishing retail population as a clearer measure for determining applicability of the 

UCMR 3 requirements. See previous comments regarding using a retail population as applicability 

criteria, including comments regarding representative sampling of consecutive systems and well 

fields.

Response: Please see response to comment code 23200 Retail Population Based Applicability.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

23300 Ground Water Representative Monitoring Locations Page 39 of 401

Comment Code: 23300 Ground Water Representative Monitoring Locations

Summary Response to Comments on Ground Water Representative Monitoring Locations: 

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 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.

EPA plans to preload as much inventory into 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. In addition, 

since all PWSs are required to report their retail population to the Safe Drinking Water Information 

System-Federal (SDWIS/Fed), this population is readily accessible to EPA when determining which 

systems are required to monitor for the UCMR 3, and will be pre-loaded into SDWARS. For water 

systems that are new to UCMR 3; EPA will pull available information from SDWIS, obtain State 

input where possible, and then load this information into SDWARS 3.

PWSs will need to review and verify their inventory in SDWARS and some 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. PWSs will have until October 1, 2012 

to update, edit or change their information/schedule in SDWARS 3. 

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

approval, conduct monitoring at representative entry point(s) 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. PWSs have until August 1, 2012 for submitting new information or 

updating existing plans. The use of representative entry points will result in fewer samples and thus 

time and cost savings to the PWS. 

Individual Comments

Commenter Name: David Chang 

Commenter Organization: Golden State Water Company (GSWC)

Letter ID: 0054

Comment ID: 31629

Comment Code: 23300

Comment: * GSWC is in agreement with the proposed rule that large systems that use ground 

water sources can propose monitoring at representative monitoring entry point(s) rather than at each 

entry point to the distribution system and also systems that purchase water with multiple 

connections from the same wholesaler can propose representative connections. This will result in 

representative sampling and also in a considerable cost savings if it is not required to monitor at 

every entry point to the distribution system. 
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January 2012

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Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations. 

Commenter Name: Phillip W. Holderness 

Commenter Organization: California-Nevada Section, American Water Works Association (CANV AWWA)

Letter ID: 0055

Comment ID: 31635

Comment Code: 23300

Comment: * CA-NV AWWA is in agreement with the proposed rule that large systems that use

ground water sources can propose monitoring at representative monitoring entry point(s) rather 

than at each entry point to the distribution system and also systems that purchase water with 

multiple connections from the same wholesaler can propose representative connections. This will 

result in representative sampling and also in a considerable cost savings if it is not required to 

monitor at every entry point to the distribution system. 

Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations. 

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31830

Comment Code: 23300

Comment: Alternate representative groundwater sampling locations 

Under 40 CFR 141.35(c)(3)(ii), the EPA establishes that large systems that use ground water sources 

and have multiple EPs can, with prior approval, conduct monitoring at representative entry point(s) 

rather than at each EP. To monitor at representative EPs, large systems must meet the reporting 

criteria specified in § 141.35(c)(3)(ii), and receive approval from EPA or the state. The EPA's

proposed changes to the rule language clarify that when identifying a representative well, the well 

must be one of the higher annual volume producing and consistently active wells.

The TCEQ generally supports the concept of allowing representative well sampling, and 

recommends that the EPA provide outreach to impacted systems to allow them to take advantage of 

this flexibility.

Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations. 

EPA regional coordinators will work with their respective states on review of the Ground Water 

Representative Monitoring Plans (GWRMPs). 
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January 2012

23300 Ground Water Representative Monitoring Locations Page 41 of 401

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31844

Comment Code: 23300

Other EPA Comment Codes and Descriptions: 24000 Reporting System/SDWARS

Comment: 2.0 Sample Location and Inventory Information: Representative Locations and Use of 

UCMR2 Approved Sites 

UCMR2 pre-populated the water system’s sources into SDWARS and required water systems to 

review and revise source locations and inventory information 240 days after date of publication of 

the final rule (i.e., August 2, 2007 for UCMR2). EPA acknowledged that the pre-populated UCMR2 

SDWARS database used water system information that were several years old and required verifying, 

correcting, and updating system data elements. Water utilities expended significant time and

resources with review and editing activities for UCMR2 implementation to ensure that the 

SDWARS inventory was accurate for source water entry points to the distribution system (EPTDS; 

after treatment, if appropriate) and included the newly required sampling location at the distribution 

system maximum residence time (DSMRT). Additionally, using state and/or EPA approved 

UCMR2 groundwater representative sampling locations or approved representative treated import 

wholesale connections will (1) avoid duplicating the regulatory review and approval process for 

UCMR3, (2) avoid re-entering source inventory information (groundwater and treated import water 

sources representative wholesaler connections), and (3) increase efficiency with UCMR3 

documentation tasks into the SDWARS database.

The SDWARS UCMR2 Source Inventory database needs to be kept in place as the "starting point or 

template" for water systems to review and revise for UCMR3. The majority of water system’s source 

inventory, both the EPTDS and DSMRT locations, will remain the same and may require minimal 

revision to (1) remove locations no longer in use (e.g., destroyed drinking water wells), (2) add new 

sources (e.g., new drinking water wells, new treatment points, new import connection from a 

wholesaler, etc.), or (3) add new UCMR3 data elements for sample sources not previously required 

for UCMR2. Under UCMR2, many water utilities monitored a representative treated import 

wholesale connection (e.g., CA treated surface water provided by major wholesaler to downstream 

water utilities via wholesale connections) quarterly at sampling locations that were approved by the 

EPA Regional office. These approved UCMR2 "representative wholesale connections" should be 

approved for UCMR3 if no changes have occurred within the water system. EPA acknowledges that 

water systems may purchase water from a wholesaler via multiple connections but are permitted to 

use a representative wholesale connection for compliance monitoring under UCMR3 (FR 

pages11721, 11722 and 141.40(a)(3) Table 1 ). Additionally, representative groundwater monitoring 

plans approved for UCMR2 should be applicable for UCMR3 if no changes occurred within the 

water system’s groundwater sources. UCMR3 indicates that after rule publication, PWSs will develop 

monitoring plans and enter sample information into the SDWARS source inventory database (FR 

pages 11722 Exhibit 4, 11723, 141.35(c)(2) and 141.35(c)(3)); however, there is no reference to use 

the existing UCMR2 SDWARS source inventory as the template to identify sources and develop the 

UCMR3 monitoring plans. OCWD recommends that use of the UCMR2 SDWARS pre-populated 

source inventory as the "starting template" be described and included in the rule’s regulatory 

language.
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January 2012

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Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31846

Comment Code: 23300

Other EPA Comment Codes and Descriptions: 24000 Reporting System/SDWARS

Comment: 3.3 Data Elements Reported with All Sample Results

EPA is proposing specific data elements be reported for each sampling event. The preamble and 

regulatory language does not provide sufficient details on "how, when, where and who" enters the 

data elements with each posted result. OCWD is very concerned how this information will be 

provided/entered for the UCMR3 program. EPA needs to evaluate the current SDWARS data entry 

format used for UCMR1 and UCMR2 and avoid the need to re-enter duplicate information for each 

sample point for each sampling event. As discussed in Section 2.0 above, EPA needs to streamline 

the SDWARS database entry steps to minimize duplication of re-entering the "same" information 

that was previously provided for UCMR2 or will be provided in the revised PWS’s upcoming 

UCMR3 source inventory data elements. Lessons learned from the UCMR2 program will save time, 

avoid double entry of information, and potentially avoid data entry errors. Recommendations to 

improve and streamline the UCMR3 SDWARS database entry activities include the following: 

* All required source identification information be entered once at the time of establishing the 

UCMR3 source inventory (under UCMR2, source information was entered before the on-set of the 

monitoring period). 

* UCMR3 SDWARS source inventory should begin with the same sites entered for UCMR2 (see 

Section 2.0 for discussion) as the "template" for PWSs to review and revise, as needed. This avoids 

re-entering duplicate information. 

* UCMR2 approved groundwater and wholesale representative sites, should be approved for 

UCMR3 as entered in SDWARS and used as the "starting template" for UCMR3 for PWSs to 

review and revise, as warranted.

* The source inventory screen in SDWARS should be open and available for review and revision for 

all sources for a PWS. Presently, only one source is "open" for review, revision, or to add site notes. 

The screen must be closed and the next source is selected to be "opened" for review, edit or to add 

notes. The individual source entry process it too time consuming and requires duplicating same 

information for List 1 and List 2 for the same source (for the draft UCMR3, there are no List 2 

chemicals so this will not be an issue but a consideration should the final UCMR3 have a List 1 and 

List 2 chemicals).

Response: Please see response to comment codes 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.
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January 2012

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Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31876

Comment Code: 23300

Other EPA Comment Codes and Descriptions: 24000 Reporting System/SDWARS

Comment: 2.0 Sample Location and Inventory Information: Representative Locations and Use of 

UCMR2 Approved Sites 

UCMR2 pre-populated the water system’s sources into SDWARS and required water systems to 

review and revise source locations and inventory information 240 days after date of publication of 

the final rule (i.e., August 2, 2007 for UCMR2). EPA acknowledged that the pre-populated UCMR2 

SDWARS database used water system information that were several years old and required verifying, 

correcting and updating system data elements. Water utilities expended significant time and

resources with review and editing activities for UCMR2 implementation to ensure that the 

SDWARS inventory was accurate for source water entry points to the distribution system (EPTDS; 

after treatment, if appropriate) and included the newly required sampling location at the distribution 

system maximum residence time (DSMRT). Additionally, using state and/or EPA approved 

UCMR2 groundwater representative sampling locations or approved representative treated import

wholesale connections will (1) avoid duplicating the regulatory review and approval process for 

UCMR3, (2) avoid re-entering source inventory information (groundwater and treated import water 

sources), and (3) increase efficiency with UCMR3 documentation tasks into the SDWARS database. 

The SDWARS UCMR2 Source Inventory database needs to be kept in place as the "starting point or 

template" for water systems to review and revise for UCMR3. The majority of water system’s source 

inventory, both the EPTDS and DSMRT locations, will remain the same and may require minimal 

revision to (1) remove locations no longer in use (e.g., destroyed drinking water wells), (2) add new

sources (e.g., new drinking water wells, new treatment points, new import connection from a 

wholesaler, etc.), or (3) add new UCMR3 data elements for sample sources not previously required 

for UCMR2. Under UCMR2, many water utilities monitored a representative treated import 

wholesale connection (e.g., CA treated surface water provided by major wholesaler to downstream 

water utilities via wholesale connections) quarterly at sampling locations that were approved by the 

EPA Regional office. These approved UCMR2 "representative wholesale connections" should be 

approved for UCMR3 if no changes have occurred within the water system. EPA acknowledges that 

water systems may purchase water from a wholesaler via multiple connections but are permitted to 

use a representative wholesale connection for compliance monitoring under UCMR3 (FR 

pages11721, 11722 and 141.40(a)(3) Table 1 ). Additionally, representative groundwater monitoring 

plans approved for UCMR2 should be applicable for UCMR3 if no changes occurred within the 

water system’s groundwater sources.

UCMR3 indicates that after rule publication, PWSs will develop monitoring plans and enter sample 

information into the SDWARS source inventory database (FR pages 11722 Exhibit 4, 11723, 

141.35(c)(2) and 141.35(c)(3)); however, there is no reference to use the existing UCMR2 SDWARS 

source inventory as the template to identify sources and develop the UCMR3 monitoring plans. 
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23300 Ground Water Representative Monitoring Locations Page 44 of 401

ACWA recommends that use of the UCMR2 SDWARS pre-populated source inventory as the 

"starting template" be described and included in the rule’s regulatory language. 

Response: Please see response to comment codes 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.

Commenter Name: Danielle Blacet 

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31878

Comment Code: 23300

Other EPA Comment Codes and Descriptions: 24000 Reporting System/SDWARS

Comment: 3.3 Data Elements Reported with All Sample Results

EPA is proposing specific data elements be reported for each sampling event. The preamble and 

regulatory language does not provide sufficient details on "how, when, where and who" enters the 

data elements with each posted result. ACWA is very concerned how this information will be 

provided/entered for the UCMR3 program. EPA needs to evaluate the current SDWARS data entry 

format used for UCMR1 and UCMR2 and avoid the need to re-enter duplicate information for each 

sample point for each sampling event. As discussed in Section 2.0 above, EPA needs to streamline 

the SDWARS database entry steps to minimize duplication of re-entering the "same" information 

that was previously provided for UCMR2 or will be provided in the revised PWS’s upcoming 

UCMR3 source inventory data elements. Lessons learned from the UCMR2 program will save time, 

avoid double entry of information, and potentially avoid data entry errors. Recommendations to 

improve and streamline the UCMR3 SDWARS database entry activities include the following: 

*All required source identification information be entered once at the time of establishing the 

UCMR3 source inventory (under UCMR2, source information was entered before the on-set of 

monitoring period). 

* UCMR3 SDWARS source inventory should begin with the same sites entered for UCMR2 (see 

Section 2.0 for discussion) as the "template" for PWSs to review and revise, as needed. This avoids 

re-entering duplicate information. 

*UCMR2 approved groundwater and wholesale representative sites, should be approved for 

UCMR3 as entered in SDWARS and used as the "starting template" for UCMR3 for PWSs to 

review and revise, as warranted.

*The source inventory screen in SDWARS should be open and available for review and revision for 

all sources for a PWS. Presently, only one source is "open" for review, revision, or to add site notes. 

The screen must be closed and the next source is selected to be "opened" for review, edit or to add 

notes. The individual source entry process it too time consuming and requires duplicating same 

information for List 1 and List 2 for the same source (for the draft UCMR3, there are no List 2 

chemicals so this will not be an issue but a consideration should the final UCMR3 have a List 1 and 

List 2 chemicals).
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

23300 Ground Water Representative Monitoring Locations Page 45 of 401

Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32038

Comment Code: 23300

Comment: 3. Implementing the proposed representative monitoring of entry-pointsto- thedistribution-system (EPTDS) and ground water wells serving the same community water systems; 

representative monitoring is essential to managing the burden of the proposed UCMR3 monitoring 

strategy.

Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32050

Comment Code: 23300

Other EPA Comment Codes and Descriptions: 23200 Retail Population Based Applicability

Comment: Monitoring Consecutive Systems in UCMR3 EPA does not specifically request

comment on whether consecutive systems should monitor under UCMR3. AWWA believes that this 

is one of the most important changes in the proposal over previous UCMR monitoring strategies. 

AWWA supports EPA’s decision to include consecutive systems in UCMR3 as a better means of 

characterizing contaminant occurrence when it is appropriate. Monitoring consecutive systems 

should occur when there is significant potential for addition, formation, or degradation of the target 

analyte within the combined distribution system. 

AWWA is also concerned with the logistics of sampling consecutive systems. EPA’s proposed 

approach, one representative connection per wholesaler, is sound.[FN4:76 Federal Register 11721] 

AWWA agrees with EPA’s proposed approach to choosing a sampling location from among 

multiple wholesale connections, that is, selection of the higher annual volume entry-points-to-thedistribution- system (EPTDS) connections, and if the connection selected as the representative

EPTDS is not available for sampling, an alternate representative connection would need to be 

sampled.[FN5:76 Federal Register 11722] AWWA agrees that this approach should be captured in 

the rule’s regulatory language with some latitude for EPA to address system-specific considerations. 

AWWA suggests a similar strategy be employed with respect to distribution-system -maximumresidence-time (DSMRT) sample locations. The UCMR3 proposal recommends a populationweighted sampling strategy for DSMRT samples based on the Stage 2 Disinfectants and 

Disinfection Byproducts Rule (Stage 2 DBPR) sampling strategy. The situation is similar to instances 

where there are multiple wells and multiple EPTDSs that characterize the same source of supply. 
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January 2012

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UCMR3 DSMRT samples, like EPTDS samples, could be focused on the selection of sites that 

reflect higher annual volume of distributed water. 

Response: Please see response to comment codes 23200 Retail Population Based Applicability and 

23300 Ground Water Representative Monitoring Locations. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080

Comment ID: 32060

Comment Code: 23300

Comment: Representative samples - AWWA strongly recommends the agency provide for 

representative monitoring when there are multiple EPTDS. This is important when there are 

multiple wells and multiple interconnects with a wholesale water provider. Note that with respect to 

wholesale water transfer, water from the same source may be "wheeled" through multiple 

wholesalers to a given water system. Consequently, while the agency’s proposal preamble and rule 

language outlines an appropriate strategy, some additional flexibility to address water wheeling 

should be retained by EPA.[FN10: 76 FR 11733 and 11735, See §141.35(c) (3)(2) for representative 

well selection and Table 1 footnote (c) for representative EPTDS selection.] The regulatory language 

should provide some latitude to EPA to address system-specific considerations, including instances 

where multiple water systems are receiving water from the same wholesaler provider. 

Response: Please see responses to comment codes 23300 Ground Water Representative 

Monitoring Locations and 23200 Retail Population Based Applicability. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

23400 Sampling Requirements Frequency Page 47 of 401

Comment Code: 23400 Sampling Requirements Frequency

Individual Comments

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31826

Comment Code: 23400

Comment: Sampling frequency and location

Sampling requirements-frequency 

Under 40 CFR 141.40(a)(4)(i)(B), the EPA clarifies that sampling points within a system may have 

different schedules depending on the presence of surface water or groundwater. As under previous 

UCMR cycles, samples at ground water locations would be collected twice during a designated 

consecutive 12-month period. Samples at locations that are fed in whole or part by a surface water 

or ground water under the direct influence of surface water (GUI) source would be collected 

quarterly during a designated consecutive 12-month period. 

The TCEQ recommends eliminating organic sampling at purchased water EPs. The scientific 

information provided by such sampling is by far outweighed by the unnecessary cost to the 

regulated community. 

Further, large system schedules (year and months of monitoring) would initially be determined by 

EPA in conjunction with the states and these systems would have an opportunity to modify this 

schedule. 

The TCEQ recommends that the EPA provide assistance to systems in some form more userfriendly than rulemaking prior to starting sampling, so that systems can take advantage of this 

offered flexibility.

Response: EPA agrees that outreach and stakeholder input are important, and will work to achieve 

this through various avenues. There will be at least one live webinar after the final UCMR 3 rule is 

published. There is also readily available information on the numerous UCMR webpages. Other 

examples of assistance are the notifications that EPA sends to the systems along with fact sheets, a 

reference guide, CRK Letters for large systems, quarterly meetings with regions, and compliance 

assistance reminders.

Please see response to comment codes 23200 Retail Population Based Applicability and 23300 

Ground Water Representative Monitoring Locations. 

Commenter Name: Yone Akagi

Commenter Organization: City of Portland, Oregon 
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23400 Sampling Requirements Frequency Page 48 of 401

Letter ID: 0088

Comment ID: 32002

Comment Code: 23400

Comment: 5. Monitoring frequency by source type.

Portland would like to see a clearer explanation of the requirements for a seasonal source. Portland 

has a seasonal groundwater source that is not typically run for more than a few weeks per year. As 

such, it would be difficult to accomplish two sampling events 5 to 7 months apart. 

Thank you again for the opportunity to provide input on this proposed rule. We will continue to 

participate and partner with you to improve the quality and safety of the nation’s drinking water 

supply. Please feel free to contact us if you have questions. 

Sincerely, Yone Akagi Water Quality Compliance Manager

Response: Due to logistical issues associated with sampling for UCMR 3 (e.g., seasonal operation of 

some wells), the final regulation also contains revised language that extends the time frame for 

collecting the second ground water sample to 5-7 months following the collection of the first round 

of samples. For planning purposes, EPA will initially schedule these sampling events 6 months apart. 

However, systems will have the flexibility to sample within a 5-7 month window. Systems will be 

required to notify EPA if they cannot monitor within this three-month window, as required under 

§141.35(c)(5).
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

23500 Revised Data Element #4 - Zip Codes Page 49 of 401

Comment Code: 23500 Revised Data Element #4 - Zip Codes

Summary Response to Comments on Revised Data Element #4 - Zip Codes: UCMR 3 

establishes a requirement for reporting zip codes associated with all PWS customers. EPA had 

proposed reporting of U.S. Postal Service Zip Codes for each 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, after considering stakeholder concerns about the burden 

associated with reporting this information, 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 §§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.

Individual Comments

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority 

Letter ID: 0062

Comment ID: 31660

Comment Code: 23500

Comment: Locational Data

MWRA cautions EPA that while the use of zip code data to identify sample location will more easily 

identify the geographic location of the sample for some purposes, that the extension of that use to 

vulnerability or exposure estimates is fraught with the possibility for error. Sample location has 

essentially nothing to do with population served. For both this reason, and due to the additional 

effort needed to collect the information, MWRA also does not support the use of zip+4 data. 

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31769

Comment Code: 23500

Comment: 3. (76 FR 11723) Addition of zip code, optional zip+4 and zip codes served for each 

sampling point identification 

While AMWA supports EPA’s proposal to have utilities include a zip code to more easily identify a 

sampling location point, this identifier would only be appropriate for generally identifying the 
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January 2012

23500 Revised Data Element #4 - Zip Codes Page 50 of 401

sampling location. The use of the sample point zip code for determining population served is a 

crude and inaccurate approximation of the population served for many reasons: 

* population served is determined by pressure zone not zip code; 

* a sampling point could serve water to multiple zip codes or only a small portion of one zip code; 

* water from multiple sources (particularly in ground water systems) could serve a single zip code; 

* a sampling point at a specific geographic location (zip code) may not be the ultimate delivery point 

(zip code) for that distributed water; 

* in utilities with seasonal variation in the community’s population, the population could change; and 

* a sampling point might only serve a fraction of the population in that zip code with the balance 

served by another utility. 

Distribution system sample points are suppose to be representative of max residence time, pressure 

zones, etc. They are not representative of the population within or served in a zip code area. 

Therefore, AMWA does not support EPA’s intention to use the sampling point zip code identifier 

to assist with future vulnerability assessments and occurrence and exposure analyses.

For similar reasons, AMWA does not support adding zip+4. The risk of error in transcribing all of 

these numbers far outweighs any potential benefit. 

In addition, AMWA does not support the use of zip codes for identifying environmental justice 

communities in which to assess UCMR monitoring results, for reasons described under Comment 

16, below.

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31797

Comment Code: 23500

Comment: D. Addition of zip code and zip code+4 for each sampling point. (76 FR 11723) 

DEP has no concerns with including zip code for each sampling point, but believe that zip_ +4 is 

overkill and provides little useful additional information. Additionally, EPA's rationale for requesting 

this information is unclear. The text states that the zip code would assist with "future vulnerability 

assessments", and it is unclear to DEP how the zip code information could inform vulnerability 

assessments, nor are vulnerability assessments a goal ofUCMR-3. The zip is also requested to help in 

"tying the population served" to each sampling point. Arguably, the zip code is more representative 

than simply an x-y coordinate, but in large cities, the zip may not provide a good indication of the 

population served. DEP suggests instead, or in addition, that EPA ask whether the utility can 
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23500 Revised Data Element #4 - Zip Codes Page 51 of 401

estimate the population served. In New York City, we’ve established a system of representative 

sampling stations for TCR and DBP compliance sampling. Each sampling station, which is where 

we draw UCMR samples from, represents approximately equal populations and would be a better 

indicator of population served than zip. 

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health

Letter ID: 0078

Comment ID: 31810

Comment Code: 23500

Comment: The collection of entry point and service area zip codes (141.35(e)) is a new data 

reporting activity requirement for Minnesota and its PWSs. Since multiple zip codes may be served 

by a water system, optional collection of only entry point zip codes will ease PWS and State data 

collection workload. The flexibility provided by allowing different schedules for sample points 

within any PWS (141.40(a)(4)(i)(B)) should improve rule implementation. 

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31834

Comment Code: 23500

Comment: To Whom It May Concern: 

Please accept the attached comments from the City of Riverside regarding the revisions to the 

Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems. Please email 

confirmation that you received our comments by replying to this email. 

Thank You, David Garcia Regulatory Affairs Manager City of Riverside Public Utilities

951.826.5612

May 1, 2011 Water Docket U.S. Environmental Protection Agency, Mail Code 282211T 1200 

Pennsylvania Avenue, NW., Washington, DC 20460 Attention: Docket ID No. OW-2009-0090

Re:Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public Water 

Systems

To Whom It May Concern: 

The City of Riverside appreciates the opportunity to comment on the proposed revisions to the 

third Unregulated Contaminant Monitoring Regulation (UCRM3). Riverside is the largest City in 
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23500 Revised Data Element #4 - Zip Codes Page 52 of 401

inland southern California, serving approximately 300,000 customers through 63,500 water service 

connections, within a service area of 75 square miles.

Riverside is an active member of the Association of California Water Agencies, (ACWA). We fully 

support the comments submitted by ACWA regarding the proposed UCMR3, and incorporate them 

herein to this comment letter by reference. Additionally, we are providing comments below as they 

relate to Riverside.

Data Elements-ZIP Codes 

The USEPA is proposing that zip code and zip code served be added to Data Element 4 (Sampling 

Point Identification Code). Although providing zip code information of each source is feasible, it is 

not clear how this information will fulfill the monitoring objectives of the UCMR program. USEPA 

states that this information will assist with future vulnerability assessments and correlating 

populations served to each sampling point would assist with future occurrence and exposure 

analyses.

Riverside would like to point out that there are several flaws with utilizing zip code information for 

these purposes. For instance, many of Riverside's sampling location zip codes do not represent the 

same zip codes as the areas being served. Thus, the use of zip codes would not provide meaningful 

and accurate information to determine population served. Furthermore, the use of zip codes is much 

too broad of a source identification to assist with developing accurate vulnerability assessments. 

Detailed information such as GPS location rather than zip code should be used to ensure that 

vulnerability assessments are conducted properly. 

Riverside believes the use of zip codes would only cause confusion among those evaluating the data 

as they are likely to be unfamiliar with each public water system's distribution system dynamics.

Therefore, Riverside does not support inclusion of the data element that requires listing of all zip 

codes served by the source (sampling point). 

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31845

Comment Code: 23500

Comment: 3.0 Data Elements

EPA is proposing several new UCMR3 data elements and request comments as noted below. 

3.1 Zip Code

New data elements proposed for UCMR3 includes adding the zip code to the sample point 

identification code (FR page 11717 Exhibit 2, 11723, 11733 Table 1, and 141.35(e)) and the zip code 
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of all areas supplied with water from the sampling point. Providing the zip code of the sampling 

point is doable; however, it is nclear how this information will fulfill the monitoring objectives of the 

UCMR program. The sampling point identification is linked to the PWS, the state, and population 

served. Frequently, the zip code of the sampling location may not be in the same zip code as the 

area served by the PWS. For example, a drinking water well may be geographically located in an 

adjacent city with water delivered to the PWS service area through a transmission line. EPA 

acknowledges that PWSs may purchase water from a wholesaler and may have multiple connections; 

however, a representative connection from the wholesaler will be the designated UCMR3 sampling 

point. The zip code of the well location or the representative wholesaler connection may not be the 

same as the PWS service area. EPA needs to provide clarification on the use and benefit of having 

the detail of zip code identification to meet the intent of the UCMR program to obtain nationwide 

occurrence data for potential future regulatory decisions. UCMR1 and UCMR2 data elements 

include the population served by the PWS, which provides the population exposed to the water 

served (see discussion below). 

3.2 Zip Code of All Areas Supplied with Water from Sampling Point

EPA is proposing that the zip codes served by the "Sampling Point" be listed with each sample. The 

basis for adding the additional service area zip code is provided in the preamble (page 11723): 

"Zip code of the sampling point would assist with future vulnerability assessments. Zip codes tying 

the population served to each sampling point would assist with future occurrence and exposure 

analyses."

Similar to the zip code data element for the sampling point (see discussion in Section 3.1), it is 

unclear how EPA will use this zip code information to fulfill one of the monitoring objectives of the 

UCMR program. The UCMR program, established by the 1986 Amendments to the Safe Drinking 

Water Act, is a monitoring program designed to collect nationwide occurrence data for unregulated 

contaminants that may be present in drinking water. Water quality data collected through the UCMR 

process are stored in the National Drinking Water Contaminant Occurrence Database (NCOD) to 

aid EPA in future regulatory determinations. A key component in the assessment process is to 

evaluate occurrence and population exposed to determine if a meaningful health risk reduction is 

achieved by establishing a national drinking water standard for the unregulated contaminant. 

Data elements currently provided in UCMR1, UCMR2 and the Safe Drinking Water Information 

System (SDWIS) database provides the population served by the PWS. Providing all potential zip 

codes for water delivered from a source to a PWS’s service area will be time consuming, challenging, 

require significant PWS resources, and will not provide the "population served" that is of interest to 

EPA for purposes of assessing population exposure. The zip code provides a geographic location 

but does not provide EPA with information on number of people. 

EPA is proposing a change in the definition of PWS population to include only a PWS’s retail 

population for UCMR3 as described in Section III.E.1. "Applicability Based on Population Served 

(FR page 11721)." Excerpts from this section, listed below, demonstrate that EPA acknowledges 

that they have easy access to the retail population by PWS, which will meet the information needed 

for nationwide exposure assessments to equate with UCMR findings: 
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* UCMR 3 requirements for systems would be based on their retail population served as reported to 

SDWIS/Fed as "Population Served" 

* Moreover, a system’s population is used to determine exposure estimates.

* Because the retail population comprises all of the people exposed to water from a particular 

system, EPA would have a clearer understanding of the number of people exposed to a detected 

contaminant. 

* The proposed change to the definition of population would allow EPA to better estimate the total 

population served by a water system and ensures that exposure calculations are more accurate.

* PWSs are required to report their retail population to the Safe Drinking Water Information 

System-Federal (SDWIS/Fed), so this population is readily accessible to EPA when determining 

which systems are required to monitor for the UCMR 3. 

As noted above, EPA states that the "Zip code of the sampling point would assist with future 

vulnerability assessments." A vulnerability assessment of a drinking water source (e.g., UCMR3 

sampling point) is not based on a zip code but is based on the drinking water source assessment to 

determine potential contaminating activities (actual or potential sources of contamination) to which 

the source is most vulnerable. Performing a vulnerability and susceptibility assessment for drinking 

water sources includes several elements, including but not limited to: (1) source location, (2) 

delineation of source protection areas or well capture zones (2-year, 5-year and 10-year time of travel 

distance), (3) land uses and potential contaminating activities (PCA) within each source protection 

area, (4) analysis of PCAs (type, proximity) and source vulnerability, (5) risk associated with the PCA 

(i.e., potential for release), (6) construction of source and geologic characteristics (i.e., drinking water

well), and (7) source water quality. OCWD does not support inclusion of the data element that 

requires listing of all zip codes served by the source (sampling point) for reasons stated above. 

Lastly, multiple sources may provide water to the same zip code which may result in inaccurate use 

of zip codes to correlate with population exposure. 

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31877

Comment Code: 23500

Comment: 3.0 Data Elements

EPA is proposing several new UCMR3 data elements and request comments as noted below. 

3.1 Zip Code

New data elements proposed for UCMR3 includes adding the zip code to the sample point 

identification code (FR page 11717 Exhibit 2, 11723, 11733 Table 1, and 141.35(e)) and the zip code 
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of all areas supplied with water from the sampling point. Providing the zip code of the sampling 

point is doable; however, it is unclear how this information will fulfill the monitoring objectives of 

the UCMR program. The sampling point identification is linked to the PWS, the state, and 

population served. Frequently, the zip code of the sampling location may not be in the same zip 

code as the area served by the PWS. For example, a drinking water well may be geographically 

located in an adjacent city with water delivered to the PWS service area through a transmission line. 

EPA acknowledges that PWSs may purchase water from a wholesaler and may have multiple

connections; however, a representative connection from the wholesaler will be the designated 

UCMR3 sampling point. The zip code of the well location or the representative wholesaler 

connection may not be the same as the PWS service area. EPA needs to provide clarification on the 

use and benefit of having the detail of zip code identification to meet the intent of the UCMR 

program to obtain nationwide occurrence data for potential future regulatory decisions. UCMR1 and 

UCMR2 data elements include the population served by the PWS, which provides the population 

exposed to the water served (see discussion below).

3.2 Zip Code of All Areas Supplied with Water from Sampling Point

EPA is proposing that the zip codes served by the "Sampling Point" be listed with each sample. The 

basis for adding the additional service area zip code is provided in the preamble (page 11723): 

"Zip code of the sampling point would assist with future vulnerability assessments. Zip codes tying 

the population served to each sampling point would assist with future occurrence and exposure 

analyses."

Similar to the zip code data element for the sampling point (see discussion in Section 3.1), it is 

unclear how EPA will use this zip code information to fulfill one of the monitoring objectives of the 

UCMR program. The UCMR program, established by the 1986 Amendments to the Safe Drinking 

Water Act, is a monitoring program designed to collect nationwide occurrence data for unregulated 

contaminants that may be present in drinking water. Water quality data collected through the UCMR 

process are stored in the National Drinking Water Contaminant Occurrence Database (NCOD) to 

aid EPA in future regulatory determinations. A key component in the assessment process is to 

evaluate occurrence and population exposed to determine if a meaningful health risk reduction is 

achieved by establishing a national drinking water standard for the unregulated contaminant. 

Data elements currently provided in UCMR1, UCMR2 and the Safe Drinking Water Information 

System (SDWIS) database provides the population served by the PWS. Providing all potential zip 

codes for water delivered from a source to a PWS’s service area will be time consuming, challenging, 

require significant PWS resources, and will not provide the "population served" that is of interest to 

EPA for purposes of assessing population exposure. The zip code provides geographic location but 

does not provide EPA with information on number of people. 

EPA is proposing a change in the definition of PWS population to include only a PWS’s retail 

population for UCMR3 as described in Section III.E.1. "Applicability Based on Population Served 

(FR page 11721)." Excerpts from this section, listed below, demonstrate that EPA acknowledges 

that they have easy access to the retail population by PWS, which will meet the information needed 

for nationwide exposure assessments to equate with UCMR findings: 
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*UCMR 3 requirements for systems would be based on their retail population served as reported to 

SDWIS/Fed as ‘‘Population Served’’

*Moreover, a system’s population is used to determine exposure estimates.

*Because the retail population comprises all of the people exposed to water from a particular system, 

EPA would have a clearer understanding of the number of people exposed to a detected 

contaminant. 

* The proposed change to the definition of population would allow EPA to better estimate the total 

population served by a water system and ensures that exposure calculations are more accurate.

*PWSs are required to report their retail population to the Safe Drinking Water Information SystemFederal (SDWIS/Fed), so this population is readily accessible to EPA when determining which 

systems are required to monitor for the UCMR 3. 

As noted above, EPA states that the "Zip code of the sampling point would assist with future 

vulnerability assessments." A vulnerability assessment of a drinking water source (e.g., UCMR3 

sampling point) is not based on a zip code but is based on the drinking water source assessment to 

determine potential contaminating activities (actual or potential sources of contamination) to which

the source is most vulnerable. Performing a vulnerability and susceptibility assessment for drinking 

water sources includes several element, including but not limited to: (1) source location, (2) 

delineation of source protection areas or well capture zones (2-year, 5-year and 10-year time of travel 

distance), (3) land uses and potential contaminating activities (PCA) within each source protection 

area, (4) analysis of PCAs (type, proximity) and source vulnerability, (5) risk associated with the PCA 

(i.e., potential for release), (6) construction of source and geologic characteristics (i.e., drinking water

well), and (7) source water quality.

ACWA does not support inclusion of the data element that requires listing of all zip codes served by 

the source (sampling point) for reasons stated above. Lastly, multiple sources may provide water to 

the same zip code which may result in inaccurate use of zip codes to correlate with population 

exposure. 

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32042

Comment Code: 23500

Comment: 7. Deleting the reporting of zip codes for the distribution system sample collection sites 

in the final UCMR3.

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 
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Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32099

Comment Code: 23500

Comment: 11.Addition of zip code, optional zip code extension, and zip codes served to Data 

Element 4-Sampling Point Identification Code. 

EPA proposes to collect zip code information for the following purposes: 

"Zip code of the sampling point would assist with future vulnerability assessments. Zip codes tying 

the populations served to each sampling point would assist with future occurrence and exposure 

analyses." (76 FR 11723)

While capturing in the dataset a zip code representative of the sample location is feasible, the 

proposed strategy, including that code and potentially the extended zip code, in the sample point 

identification code appears on its face to be problematic. The sample point identification code 

should be as simple and short as possible to avoid data entry errors and facilitate routine database 

management.

For the same reason, it is inappropriate to an even greater degree to include the "zip codes served" 

in the sample point identification code. One EPTDS could literally serve numerous zip codes (both 

complete and partial zip codes) and thus create a significant potential for data entry. Moreover, EPA 

is proposing that submitting each sample observation require re-entering this data. This would 

substantially increase the difficulty of data entry and likely lead to significant quality control 

challenges in the resulting dataset. An additional challenge in the proposed UCMR3 framework is 

that water systems that are purchasing water and systems that are selling water (wholesalers) would 

face a difficult challenge reliably identifying what zip codes are served across multiple water systems. 

Distribution systems typically do not follow zip codes boundaries. 

AWWA is concerned that the agency believes that the UCMR dataset is adequate to support 

vulnerability assessment and exposure analysis at a detailed level (e.g., zip codes). The UCMR3 

dataset is not collected for that purpose nor is it sufficient robust to support such analyses. To 

communicate to the public that the UMCR data is adequate to this task is misleading to the agency’s 

risk managers and the public. UCMR data is designed to support national regulatory decisionmaking:

1. Characterizing the national occurrence of an analyte in finished water, and

2. Informing the national cost estimate of regulatory actions. 

Adding additional data collection for future unspecified potential research activities will dilute the 

focus of UCMR3.

Finally, the utility of the zip code as a spatial identifier is uncertain. General attributes of zip codes 

that make their use for any subsequent analysis challenging including that zip codes are: 
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1. Not tied to any fixed geographic features, 

2. Not directly or consistently linked to census information, and 

3. Not consistent over time. 

Inclusion of zip code extension implies a very specific area within a postal route and is a field that 

deliberately includes information lacking a geographic context (e.g., post office boxes, etc.).

Response: Please see response to comment code 23500 Revised Data Element #4 - Zip Codes. 
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Comment Code: 23600 Revised Data Element #6 - Disinfectant Type

Summary Response to Comments on Revised Data Element #6 - Disinfectant Type: EPA 

will clearly indicate in the data reporting system (SDWARS) that PWSs should identify all of the 

disinfectants and techniques (including ozone and UV) used to treat the water. Systems that use 

either potassium or sodium hypochlorite solutions will be required to identify the source of the 

solution (generated on- or off-site). A revised set of disinfection type codes is included in the final 

UCMR 3 rule. This list will provide more specific information on the sources and types of 

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

The list now includes: 

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

Individual Comments

Commenter Name: Therese M. Cirone

Commenter Organization: The Chlorine Institute 

Letter ID: 0053

Comment ID: 31625

Comment Code: 23600

Comment: May 2, 2011 - Electronic Submission Water Docket United States Environmental 

Protection Agency 1200 Pennsylvania Avenue, NW Washington, DC 20460-0001

Re: Docket ID No. OW-2009-0090

These comments are submitted in response to the Proposed Rulemaking, published in the Federal 

Register on March 3, 2011, OW- 2009-0090, with respect to the revisions to the Unregulated 

Contaminant Monitoring Regulation (UCMR 3). 

The Chlorine Institute (the Institute or CI) is a 200 member, not-for-profit trade association of 

chlor-alkali producers worldwide, as well as packagers, distributors, users, and suppliers. The 

Institute’s mission is the promotion of safety and protection of human health and the environment 

in the manufacture, distribution and use of chlorine, sodium hydroxide, potassium hydroxide and 

sodium hypochlorite, plus the distribution and use of hydrogen chloride. The Institute’s North 
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American Producer members account for more than 96% of the total chlorine production capacity 

of the U.S., Canada, and Mexico.

Chlorate Monitoring - Data Element 6

EPA is proposing that Drinking Water Systems (systems) report Data Element 6 (disinfectant type) 

in use at the time of UCMR monitoring. The reason indicated for this change is to assist EPA in 

evaluating chlorate sample results.

While this approach may provide some technical assistance to EPA, the disinfectant categories as 

presented are confusing and redundant and if utilized may create confusion in evaluating results. For 

example, the disinfectant-in-use choices include sodium hypochlorite solution, potassium 

hypochlorite solution, hypochlorite generated off-site and hypochlorite generated at the DW facility.

As written it appears that sodium hypochlorite solution and hypochlorite generated off-site are 

different disinfectant types and that is not a correct assessment.

We would recommend that EPA simplify the delineation of hypochlorite by indicating whether it is 

purchased from an off-site location or produced on- site and then indicate whether it is sodium 

hypochlorite or potassium hypochlorite. Additionally, the system should also provide the strength of 

the hypochlorite solution with the dosage amount. 

Response: Please see response to comment code 23600 Revised Data Element #6 - Disinfectant 

Type.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31770

Comment Code: 23600

Comment: 4. (76FR11723 and 11733) Revised data element #6 (Clarify and update the disinfectant 

in use at the time of UCMR monitoring.) 

In its proposal, EPA says that including additional disinfection types is to "accommodate recent 

advances and changes to disinfectant technologies being used by water systems." While including 

disinfectant type with regard to chlorate fate and transport could be useful information to collect to 

inform rule development, AMWA urges EPA to thoroughly explain the purpose for including this 

information in the UCMR reporting. It is unclear how this information would inform future 

rulemaking for contaminants other than chlorate. 

EPA’s proposal for including disinfectant type at a DSMRT is oversimplified and is unlikely to 

support any DBP analysis, such as for chlorate. Therefore AMWA recommends that EPA’s 

proposal for revising data element #6 should be revised to consider and identify: 

* all possible disinfection options (including booster disinfectants), including identifying BOTH the 

primary and secondary disinfectants; and
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* ozone and UV as primary disinfectant options, rather than including these as "other." 

In addition, EPA must consider that the disinfectant type at sampling locations for utilities that 

purchase water could be a mixture of several disinfectants. For example, one of AMWA’s member 

utilities in California uses ozone as its primary disinfectant and sodium hypochlorite for secondary 

disinfection. The system purchases water from a wholesaler that uses ozone and monochloramine.

These two waters are not isolated and can mix in the distribution system. EPA needs to provide a 

means to allow multiple disinfectant entries to characterize the DSMRT.

Another option to consider is to not sample any distribution sites where there is a high probability 

of having water disinfected by different methods on different days and thus producing results that 

are not comparable.

If EPA decides to move forward with revising the requirements for data element #6, then the 

agency should clearly describe in its final rule what is being asked and for what purpose. AMWA 

also recommends that EPA consider working with utility and primacy agency associations and 

entities in order to ensure that the final requirement is sufficient and appropriate to supports the 

analyses that EPA envisions and identifies in the final rule. 

Response: Please see response to comment code 23600 Revised Data Element #6 - Disinfectant 

Type.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31772

Comment Code: 23600

Comment: 7. Reporting monitoring results - all elements in Table 1 with each sample (previously 

only a subset was reported w/each)

AMWA tentatively supports EPA’s rationale that the additional information will help the agency 

assess chlorate results, as long as the recommendations expressed under Comment 4, above, are 

included in the final rule. 

Response: Please see response to comment code 23600 Revised Data Element #6 - Disinfectant 

Type.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ)

Letter ID: 0087

Comment ID: 31833

Comment Code: 23600

Comment: Reporting monitoring results 
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Under 40 CFR 141.35(c)(6) and 141.35(d)(2), the EPA requires small and large systems to report all 

data elements, including disinfectant residual in Table 1 with each sample. Previously, only a subset 

of the data elements was to be reported with each sample.

The TCEQ agrees with the addition of reporting disinfectant type and concentration for monitoring 

data under UCMR 3. 

Response: Please see response to comment code 23600 Revised Data Element #6 - Disinfectant 

Type.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31868

Comment Code: 23600

Comment: Revised data elements: The disinfectant information requested in 40 CFR 141.35 Table 

1 - Unregulated Contaminant Monitoring Reporting Requirements (page 11733) should be 

reconsidered. Overall, the inclusion of data element 6 is an acceptable change. However, the list 

itself has some problems. Expansion of disinfectant types to include processes like chlorine dioxide 

makes sense; however, ozonation and ultraviolet disinfection should also be specifically identified by 

their own treatment code. In addition, multiple disinfectants will need to be listed, possibly by 

changing the data element to "disinfectant type(s)" rather than "disinfectant type". In many cases, 

water systems use multiple disinfectants in their treatment processes and a single value will not

capture reality in these situations. A more extensive revision here, for consideration in UCMR3 or 

future cycles, would be to revise data element 6 to be inclusive of all "treatment processes." This 

modification could be coupled with an expansion of sample sites to include samples collected from 

sources prior to treatment.

Response: Please see response to comment code 23600 Revised Data Element #6 - Disinfectant 

Type.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32100

Comment Code: 23600

Comment: 12.[Use of] additional disinfectant types to accommodate recent advances and changes 

to disinfectant technologies being used by water systems The proposal repeats the error observed in 

UCMR2 nitrosamine data, in that the disinfectant practice is not clearly characterized. The proposed 

data element does not capture the distinction between primary and secondary disinfection. 

"The disinfectant in use at the time of UCMR monitoring. To be reported by systems for each 

sampling point, with possible values including: 
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CLG = gaseous chlorine. CLS = Sodium hypochlorite solution. CLP = Potassium hypochlorite 

solution. CAG = chloramine (gaseous chlorine). CAS = chloramine (sodium hypochlorite solution). 

CAP = chloramine (potassium hypochlorite solution). CLD = chlorine dioxide. GOS = 

Hypochlorite generated off site. GIH = Hypochlorite generated at DW facility. OTH = all other 

types of disinfectant (e.g. ozone). NOD = no disinfectant used."(76 FR 11733)

The collection of disinfectant used can be appropriate data to collect in UCMR. For example, in 

UCMR2, it was very relevant to the observed nitrosamine occurrence; unfortunately, the data 

collected in UCMR2 was not structured in a way that was informative. With the exception of 

informing the chlorate occurrence data, it is not clear that disinfection practice is critical to the

proposed UCMR3 dataset. 

If EPA is going to collect data on disinfection practice as a component of the proposed UCMR3, 

then it should: 

1. Obtain what disinfectant(s) is (are) used for primary disinfection, 

a. With respect to primary disinfection, the disinfectant options should be limited to free chlorine, 

monochloramine, ozone, chlorine dioxide, and ultraviolet light, other, none; 

2. Obtain what disinfectant is used for secondary disinfectant residual, 

a. With respect to secondary disinfection, the disinfectant options should be limited to free chlorine, 

monochloramine, chlorine dioxide, other, and none; and 

3. What is predominant form of chlorine used 

a. For primary disinfection, with the following options provided: gaseous chlorine, hypochlorite 

generated off site, hypochlorite generated on site, other, none; and 

b. For secondary disinfectant residual, with the following options provided: gaseous chlorine, 

hypochlorite generated off site, hypochlorite generated on site, other, and none. 

These recommended disinfectant data elements are sufficiently clear that they can be completed 

accurately by water system staff and sufficiently detailed to support analyses to support regulatory 

decision making. 

EPA should consider also collecting data to characterize treatment at the participating water 

systems. Since UCMR data collection is for finished water, understanding the level of treatment that 

precedes the observed occurrence is important to understanding the data. Including this data in 

UCMR3 could become both a significant data entry and data quality challenge if it is not developed 

in concert with the water system community. If the EPA pursues this recommendation, AWWA 

urges the agency to engage AWWA in a stakeholder process to determine what data elements are 

needed, how to best capture this information, and how to handle this data once collected. 

Response: Please see response to comment code 23600 Revised Data Element #6 - Disinfectant 

Type.
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Comment Code: 23800 Revised Reporting Time Frames

Summary Response to Comments on Revised Reporting Time Frames: After considering 

public comments, two proposed deadlines related to reporting of monitoring data were increased, as 

suggested. EPA extended the proposed time frame for laboratories to post data to SDWARS to 

within 120 days of sample collection (the same time frame used in earlier UCMRs). In addition, large 

systems must review, approve, and submit the data to their State and EPA within 60 days of when 

the laboratory posts the data (the same time frame used in earlier UCMRs). These time frames are 

specified in 141.35(c)(6)(ii) and 141.40(a)(5)(vi).

Individual Comments

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority

Letter ID: 0062

Comment ID: 31659

Comment Code: 23800

Comment: Reporting Timeframes

EPA requested comment on shortening the timeframes for reporting data. MWRA sees no 

particular benefit to reducing the reporting timeframes in the context of the UCMR. We would be 

particularly concerned with reducing the time that a water system has to review and approve data 

from 60 days to 30. While water systems are used to quick turn-around times for reviewing and 

reporting on regular monitoring for regulated contaminants, the UCMR represents new types of 

information on an unfamiliar schedule. Review of these data may not easily fit into existing work 

schedules, and review may require consultation beyond that normally needed for more familiar 

analytes. Water system staffs already have very full schedules to achieve existing required turnaround 

of data for regulated sampling. The danger of shortening the time frame is that systems will either 

miss the new deadline resulting in automatic approval or give short shrift to careful review of these 

data; both open the possibility of faulty data being part of the final data set. 

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31684

Comment Code: 23800

Comment: Page 11723

EPA requests comment on these shortened reporting timeframes. 
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(UCMR1 and UCMR2 allowed labs 120 to post data and systems 60 days to review, approve and 

report after posting. UCMR3 proposes 60 days for posting and 30 days to review, approve and 

report.)[...] NMED Comment

The shortened reporting timeframes are acceptable.

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31750

Comment Code: 23800

Comment: 12. We believe that because of the complexities of data related to field blank issues and 

the trace level measurements being conducted for several of the UCMR3 methods, it is appropriate 

to keep the reporting time frames the same as those used in UCMR2. With the very low MRLs for 

many of the methods, utilities (and labs) will need to do further scrutiny of data to ensure that what 

is uploaded is accurate.

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31771

Comment Code: 23800

Comment: 5. Demonstrating representative ground water sampling locations 

AMWA recommends that EPA provide guidance in the preamble of the final rule about the criteria 

for determining what constitutes a sampling site "more consistently active in a representative array" 

in ground water systems. AMWA recommends that EPA consider allowing a utility to propose a 

representative source - i.e., a well from its approved Ground Water Rule wells. AMWA also

recommends that the final rule specify that if EPA does not respond to the utility’s proposed site 

within 60 days that the source will be considered to be accepted.

6. Reporting schedule 

AMWA urges EPA to retain the 120-day timeframe for labs to electronically report results to the 

utility. AMWA also urges EPA to retain the 60-day timeframe for utilities to review and approve the 

data. Glitches can occur in communication between laboratories and utilities. For example, in the 

past some utilities were not notified that the laboratory had uploaded data to the UCMR data system 

until a few weeks later. UCMR sampling is not a task that utilities perform during the normal course 

of business. Particularly for large systems, where several staff members must coordinate schedules to 

review the data, it is important to have this amount of time for review. Especially for those utilities 
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(i.e. consecutive systems) that have not been previously covered by the UCMR, having sufficient 

time to communicate with the laboratory to verify and approve the data is very important, and 60 

days is the preferred timeframe.

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31800

Comment Code: 23800

Comment: F. Reporting Schedule (76 FR 11723)

For large systems, EPA is proposing that systems require their laboratories to post data to EPA's 

electronic data reporting system within 60 days of sample collection, and review and approve the 

data within 30 days thereafter. This is a substantial change from previous UCMR cycles of 120 and 

60 days, respectively. DEP urges EPA to retain the 120 day timeframe for labs to electronically 

report results to the utility, and most especially the 60 day window for review, approval and 

reporting of data. Particularly with these new methods and sensitive MRLs, based on DEP's 

experience with emerging contaminants, additional time will be required to adequately assess the 

laboratory methods and QAQC. Depending on the sampling cycle, large laboratories may not have 

sufficient time to conduct the necessary reviews within 30 days, say if senior laboratory personnel 

are involved with generating an annual report, or in the midst of an ELAP or NELAC audit, etc. 

Certainly, the 30 day review period is insufficient for all laboratories to meet at all times of the year.

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31832

Comment Code: 23800

Comment: Reporting 

Reporting schedule 

Under 40 CFR 141.35(c)(6)(ii) and 141.40(a)(5)(vi), the EPA reduces time for labs to electronically 

report results (from 120 to 60 days); and for systems to review, approve, and report data (from 60 to 

30 days).

The TCEQ does not disagree with the reduction in allowed reporting period. Given this reduction 

in review time, the TCEQ agrees with EPA's provision to consider non-detect data valid if a system 

has not validated it on-line within the given time period. However, the TCEQ highly recommends 
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that the EPA make a good faith effort to contact systems before automatically validating nondetects.

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31885

Comment Code: 23800

Comment: Page 11723: "EPA requests comment on these shortened reporting timeframes."

The shortened reporting timeframes are acceptable. Laboratories and water systems should be able 

to meet these schedules and it will streamline the processing of data. However, EPA should not rely 

solely on water systems and their agreements with laboratories to control the timely reporting of 

laboratory results. EPA should also make timely reporting a condition of their laboratory approval 

for UCMR3.

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32041

Comment Code: 23800

Comment: 6. Maintaining the same reporting timeframes from UCMR2 for the final UCMR3.

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32097

Comment Code: 23800

Comment: 9. Shortened reporting (e.g., QA/QC) timeframes; after state review - immediate upload 

to NCOD at end of each quarter during data collection. AWWA does not support reducing the time 

available to report data as speeding up the reporting process does not better inform regulatory 

decision-making. The current proposal reflecting expanding the UCMR monitoring program to 

many more systems than have participated previously, reporting sample observations at nanogram 

per liter concentrations, requiring monitoring from multiple sampling points, and using analytical 

methods (and sample handling protocols) that are not in routine use. These are all new challenges 

for UCMR3 implementation. Consequently, adequate time is needed not just for the majority of 
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samples that are processed smoothly, but for those where challenges arise. The proposed rule text 

reads as follows:

"You [the CWS] must ensure that your laboratory posts the data to EPA’s electronic data reporting 

system within 60 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 to EPA’s electronic reporting 

system, the data will be considered approved by you and available for State and EPA review." (76 

FR 11733)

Shorter reporting and quality assurance timeframes are a source of concern particularly if the data 

will be immediately uploaded to NCOD. Participating in UCMR is an ancillary task to operating a 

water system 24 hours a day, 365 days a year. Review of observations recorded by the laboratory 

requires coordination between the laboratory and the water system and that coordination will be

variable given utility and laboratory workloads. Together, these factors necessitate maintaining the 

current review window so that not only can the time be set aside for necessary and appropriate 

QA/QC but also to allow for adequate time for information exchange with the laboratory and a 

buffer in the time window for instances when information exchange does not occur expeditiously. 

The need for an adequate review period is compounded by the fact that to-date in UCMR 

monitoring, water systems have not been allowed to correct data once it was uploaded at the end of 

the current review window. The absence of adequate review by water systems and this feature of the 

UCMR2 data system is a likely contributor to inadequacies in the ancillary disinfection practice data. 

As demonstrated by Blute et al (2010), the poor quality of this ancillary data significantly impedes 

analysis of the UCMR2 nitrosamine data. Disinfectant practice is a key variable in the occurrence of 

nitrosamines, but the UCMR2 dataset does not allow researchers to understand disinfectant practice 

at many water systems observing nitrosamines.[FN19: Blute et al., 2010, Nitrosamine Occurrence in 

the U.S.-Analysis and Interpretation of UCMR2 Data, Water Quality and Technology Conference, 

AWWA, Savannah, GA.]

With these issues in mind, EPA should: 

1. Retain the current 120 day window for laboratory reporting and 60 day window for systems to 

review, approve, and report data,

2. Revisit and change its policies regarding water system access to uploaded data for purposes of 

correction after the initial review period,

3. Open a dialogue with water systems and laboratories in calendar year 2011 about how to simplify 

data entry and increase the effectiveness of QA/QC opportunities, and 

4. Retain 60-day state review period. Given current state staffing challenges, a shorter review period 

is an unnecessary burden on state programs. 

Response: Please see response to comment code 23800 Revised Reporting Time Frames.

PWSs can change the data after it has been uploaded. SDWARS provides an option to ask the lab to 

pull the data back, correct the data, and re-post. 
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The laboratory approval program and PT process both support communication with labs and PWSs 

regarding QA/QC issues and data entry. 
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Comment Code: 23810 Laboratory Reporting Time

Summary Response to Comments on Laboratory Reporting Time: After considering public 

comments, the proposed deadline related to laboratory posting of monitoring data to SDWARS was 

increased, as suggested, to within 120 days of sample collection. This time frame is the same as 

required under earlier UCMRs.

Individual Comments

Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31720

Comment Code: 23810

Comment: 3. Laboratory Result Reporting Schedule. The proposed UCMR3 reduces the time 

laboratory staff has to enter sample results into SDWARS from 120 days to 60 days. EPA believes 

this will help ensure compliance with monitoring schedules. CVWD does not agree with this 

reasoning because complying with sample collection schedules is the responsibility of water agencies, 

not the analyzing laboratory. CVWD believes shortening the time will not increase monitoring 

compliance and will just limit the time analyzing laboratories have to implement adequate quality 

control measures to ensure accurate water quality results are reported into SDWARS. CVWD 

believes analyzing laboratories should be provided the same 120 days allowed for UCMR2 to report 

analytical results during the implementation of UCMR3. 

Response: Please see response to comment code 23810 Laboratory Reporting Time.

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31762

Comment Code: 23810

Comment: 3. Laboratory Result Reporting Schedule. The proposed UCMR3 reduces the time 

laboratory staff has to enter sample results into SDWARS from 120 days to 60 days. EPA believes 

this will help ensure compliance with monitoring schedules. WESTCAS does not agree with this 

reasoning because complying with sample collection schedules is the responsibility of water agencies, 

not the analyzing laboratory. WESTCAS believes shortening the time will not increase monitoring

compliance and will just limit the time analyzing laboratories have to implement adequate quality 

control measures to ensure accurate water quality results are reported into SDWARS. WESTCAS 

believes analyzing laboratories should be provided the same 120 days allowed for UCMR2 to report 

analytical results during the implementation of UCMR3. 

Response: Please see response to comment code 23810 Laboratory Reporting Time.
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Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31808

Comment Code: 23810

Comment: Comment Clerk: We appreciate the opportunity to provide comment on the Revisions 

to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems. We 

offer the attached comments. Please see the attached file(s).

Sincerely, David Rindal, P.E. for Randy Ellingboe, P.E.

May 2, 2011

Water Docket United States Environmental Protection Agency, Mail Code 282211T 1200 

Pennsylvania Avenue, NW. Washington, DC 20460 Attention: Docket ID No. OW-2009-0090

Comment Clerk:

We appreciate the opportunity to provide comment on the Revisions to the Unregulated 

Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems, published in the Federal 

Register on March 3, 2011. We offer the enclosed comments. This letter is submitted on behalf of 

the Minnesota Department of Health (MDH) Drinking Water Protection Section, the primacy 

enforcement agency of the Safe Drinking Water Act (SDWA) in Minnesota.

We offer several comments related to the Requirements of the Unregulated Contaminant 

Monitoring Program. The reduced time allowed for laboratories to electronically report results 

(141.35(c)(6)(ii) and 141.40(a)(5)(vi)), from 120 to 60 days, should improve data collection and 

processing. 

Response: Please see response to comment code 23810 Laboratory Reporting Time.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31847

Comment Code: 23810

Comment: 4.0 Reporting Schedule 

EPA is proposing several new UCMR3 data reporting schedule changes and request comments as 

noted below. 

4.1 Laboratory Reporting Schedule 
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UCMR3 proposes a shortened reporting time frame for laboratories to post analytical results to 

EPA’s electronic data reporting system/SDWARS (FR pages 11717 Exhibit 2, 11723, 

141.35(c)(6)(ii), and 141.40(a)(5)(vi)). Under UCMR1 and UCMR2, the laboratory reporting time 

frame was 120 days after the date of sample collection but has been shortened to 60 days (50% 

reduction) under the proposed UCMR3. The basis for shortening the reporting and approval time 

frame was to (1) ensure compliance with established UCMR3 monitoring schedules and (2) reduce 

the chance of scheduled monitoring being missed or delayed. Reducing the reporting time by the 

laboratory does not ensure compliance with meeting a compliance sample collection date. The water 

system is responsible to ensure that drinking water sources are scheduled and UCMR3 samples are 

collected and delivered to the analyzing laboratory. Under UCMR2, the month prior to scheduled 

monitoring, an automated email from EPA CDX was sent to the PWS contact advising of the

upcoming monitoring, therefore, providing a courtesy reminder to schedule appropriate source 

monitoring. Scheduling and collecting samples of the UCMR3 sources are not the responsibility of 

the analyzing laboratory and shortening their reporting timeline for these reasons seems 

unwarranted. 

Consideration must be given that laboratories are processing other samples for a diverse range of 

compliance and non-compliance programs and includes extensive and stringent UCMR3 quality 

assurance procedures and sample reporting criteria. Reducing the reporting timeline by 60 days 

imposes a significant burden on laboratories to meet the questionable shortened timeline. The 

UCMR3 contaminant list includes analyzing for 23 organic analytes using GC/MS, and LC/MS/MS 

methods. Three of the methods require labor intensive extraction procedures that must be 

completed within 14-days of the sample collection date. The EPA approved methods provide up to 

28-days to analyze the extract. Unexpected laboratory issues do occur (e.g., instrument problems, 

replacement columns, etc.) which may require the laboratory to analyze the extract within the 

method holding time of up to 42 days. 

As noted in UCMR2 and applicable to UCMR3, the quality assurance and quality control 

requirements (data quality objectives) are stringent and must be met for SDWARS reporting. It was 

not uncommon for laboratories to analyze a second extract or request resamples due to quality 

assurance samples failing to meet UCMR data quality objectives. Examples of quality control 

required samples include the following with each sample set: 

* Internal calibration - meeting acceptance criteria * LRB - laboratory reagent blank * LFB - 

laboratory fortified blank * CCC - continuous calibration checks * IS - internal standards * LFSM - 

laboratory fortified sample matrix * LFSMD - laboratory fortified sample matrix duplicate * QCS - 

quality control sample * FD - field duplicate 

UCMR3 also includes several new methods that are not routinely nationally in drinking water 

laboratories and will require use of more sophisticated technology and instrumentation. Laboratories 

will expend more time with quality assurance tasks with the newer and challenging methods 

tentatively listed with minimum reporting limits in the sub-parts per billion and parts per trillion 

ranges (e.g., EPA methods 537 and 539) and providing the 120 days as provided for UCMR1 and 

UCMR2 is well warranted. OCWD recommends keeping the 120 day reporting schedule for 

laboratories to report data to SDWARS. 

Response: Please see response to comment code 23810 Laboratory Reporting Time.
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Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31879

Comment Code: 23810

Comment: 4.0 Reporting Schedule 

EPA is proposing several new UCMR3 data reporting schedule changes and request comments as 

noted below 

4.1 Laboratory Reporting Schedule

UCMR3 proposes a shortened reporting time frame for laboratories to post analytical results to 

EPA’s electronic data reporting system/SDWARS (FR pages 11717 Exhibit 2, 11723, 

141.35(c)(6)(ii), and 141.40(a)(5)(vi)). Under UCMR1 and UCMR2, the laboratory reporting time 

frame was 120 days after the date of sample collection but has been shortened to 60 days (50% 

reduction) under the proposed UCMR3. The basis for shortening the reporting and approval time 

frame was to (1) ensure compliance with established UCMR3 monitoring schedules and (2) reduce 

the chance of scheduled monitoring being missed or delayed. Reducing the reporting time by the 

laboratory does not ensure compliance with meeting a compliance sample collection date. The water 

system is responsible to ensure that drinking water sources are scheduled and UCMR3 samples are 

collected and delivered to the analyzing laboratory. Under UCMR2, the month prior to scheduled 

monitoring, an automated email from EPA CDX was sent to the PWS contact advising of the 

upcoming monitoring, therefore, providing a courtesy reminder to schedule appropriate source 

monitoring. Scheduling and collecting samples of the UCMR3 sources are not the responsibility of 

the analyzing laboratory and shortening their reporting timeline for these reasons seems 

unwarranted. 

Consideration must be given that laboratories are processing other samples for a diverse range of 

compliance and non-compliance programs and includes extensive and stringent UCMR3 quality 

assurance procedures and sample reporting criteria. Reducing the reporting timeline by 60 days 

imposes a significant burden on laboratories to meet the questionable shortened timeline. 

The UCMR3 contaminant list includes analyzing for 23 organic analytes using GC/MS, and 

LC/MS/MS methods. Three of the methods require labor intensive extraction procedures that must 

be completed within 14-days of the sample collection date. The EPA approved methods provide up 

to 28-days to analyze the extract. Unexpected laboratory issues do occur (e.g., instrument problems, 

replacement columns, etc.) which may require the laboratory to analyze the extract within the 

method holding time of up to 42 days. Therefore, requiring the laboratory to post results, including 

required quality assurance data results, within 60-days is not reasonable. As noted in UCMR2 and 

applicable to UCMR3, the quality assurance and quality control requirements (data quality 

objectives) are stringent and must be met for SDWARS reporting. It was not uncommon for 

laboratories to analyze a second extract or request resamples due to quality assurance samples failing 

to meet UCMR data quality objectives. Examples of quality control required samples include the 

following with each sample set:
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* Internal calibration - meeting acceptance criteria

* LRB -laboratory reagent blank

* LFB - laboratory fortified blank 

* CCC - continuous calibration checks 

* IS - internal standards 

* LFSM - laboratory fortified sample matrix

* LFSMD - laboratory fortified sample matrix duplicate

* QCS - quality control sample

* FD - field duplicate 

Response: Please see response to comment code 23810 Laboratory Reporting Time.
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Comment Code: 23820 PWS Review Time

Summary Response to Comments on PWS Review Time: After considering public comments, 

the proposed deadline related to PWS review and approval of monitoring data was increased, as 

suggested. The final rule requires that large systems review, approve, and submit the data to their 

State and EPA within 60 days of when the laboratory posts the data. EPA extended the March 3, 

2010 proposed time frame of 30 days, as suggested by commenters. The required timing for PWS 

reporting was returned to "60 days from when the laboratory posts the data", as was required under 

UCMR 1 and UCMR 2. If a PWS does not electronically approve and submit the laboratory data 

within 60 days, the data is then considered approved and final for State and EPA review. This time 

frame is specified in 141.35(c)(6)(ii) and 141.40(a)(5)(vi).

Individual Comments

Commenter Name:

Commenter Organization: Northern Kentucky Water District

Letter ID: 0060

Comment ID: 31645

Comment Code: 23820

Comment: May 2, 2011 Water Docket United States Environmental Protection Agency Mail Code 

282211 T 1200 Pennsylvania Ave., NW Washington, DC. 20460 Attention Docket ID No.: OW2009-0090

The Northern Kentucky Water District appreciates the opportunity to comment on the "Revisions 

to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public Water Systems". There 

are a few issues that we are concerned about and would like to bring to your attention. 

We would like to make sure that the EPA takes into consideration the System's time to review, 

approve and report data. (141.35(c )(6)(ii) It would be helpful to see the system review time 

increased to 60 days unless there is some type of electronic notification that the utility receives 

immediately after the data is reported to EPA. Otherwise by the time the utility receives the results 

from the lab, it could limit the time that the utility has to review and approve the data.

Response: Please see response to comment code 23820 PWS Review Time.

Commenter Name: Deborah H. Metz

Commenter Organization: Greater Cincinnati Water Works (GCWW)

Letter ID: 0085

Comment ID: 31710

Comment Code: 23820

Comment: 5. Reporting UCMR 3 data to the States/EPA 
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a. We recommend keeping the reporting requirement of 60-days as was for UCMR 1 and UCMR 2. 

Public utilities are facing budget and resource shortages and the 60-day requirement was needed 

during previous data collection efforts. This allows adequate time for the lab to report the data to 

the utility and then allow the utility enough time to review the submittal. Keeping the reporting

requirement to 60-days will ensure adequate time for data verification.

Again, we appreciate the opportunity to comment on the UCMR 3 monitoring and reporting 

revisions.

If you have any questions or need clarifications, please contact this office at (513) 624- 5600.

Sincerely,

Deborah H. Metz, Superintendent Water Quality and Treatment Division

cc: Biju George Interim Director of Greater Cincinnati Water Works

Response: Please see response to comment code 23820 PWS Review Time.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31805

Comment Code: 23820

Comment: 3. The final UCMR 3 requirements should maintain the existing 60-day time period for 

water systems to review, reanalyze (if needed), approve, and submit UCMR data.

In draft 40 CFR § 141.35(c)(6)(ii) (76 FR 11733) and in Exhibit 2 (76 FR 11717), EPA has proposed 

to limit water systems to 30 days to "review, approve, and submit" UCMR 3 analytical data for 30 

constituents across a total of 7 (6 chemical and 1 biological) test methods. EPA requested comment 

on this shortened reporting timeframe (76 FR 11723).

In UCMR 1 and UCMR 2, EPA allowed water systems 60 days for review, approval, and submission 

of data resulting from traditional water analytical methods such as GC/MS. Although EPA included 

LC/MS/MS monitoring (Method 535) for Screening Survey List 2 contaminants in UCMR 2, the 

UCMR 3 proposed rule includes List 1 Assessment Monitoring for analytes using LC/MS/MS for 

the first time in the Unregulated Contaminant Monitoring Program. In fact, the EPA proposal 

includes LC/MS/MS Assessment Monitoring for two groups of UCMR 3 analytes. Without 

adequate time to review the results from these new LC/MS/MS analytical methods, water systems 

are less likely to be able to assess the impact of contamination on reported values. 

In light of general constraints on laboratory turnaround time and the potential for LC/MS/MS 

instrument outages, a 30-day review period would effectively preclude water systems from being able 

to have samples reanalyzed where such reanalysis is triggered by data validation review. Cutting the 

available review time in half, while requiring water systems to review data from a new and untested 
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analytical technology, is not consistent with providing data upon which EPA can reliably predict 

national occurrence of chemical contaminants in drinking water. 

EPA should maintain the existing 60-day period for water systems to review, reanalyze (if needed), 

approve, and submit UCMR 3 data. 

Response: Please see response to comment code 23820 PWS Review Time.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31809

Comment Code: 23820

Comment: However, we prefer to retain a 60 day public water supply (PWS) and/or State review 

and approval time span over a reduction to 30 days. The proposed change will pose challenges to 

Minnesota’s centralized statewide drinking water analysis and reporting system. 

Response: Please see response to comment code 23820 PWS Review Time.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31848

Comment Code: 23820

Comment: 4.2 Water System Review and Approve Laboratory Data Schedule

UCMR3 revises the time period for PWS to review and approve laboratory data from from 60 days 

to 30 days (FR pages 11717 Exhibit 2, 11723, and 141.35 (c)(5) (vi)). Water utilities faced significant 

challenges with oversight, management and coordination of UCMR2 tasks, including coordination 

with field personnel and laboratories for source sampling and delivery of samples to the analyzing

laboratory. Implementation of the UCMR2 program was in addition to managing their water 

system’s operation, maintenance, and routine source and distribution system compliance monitoring 

and reporting requirements. New for UCMR3 is the requirement to collect field blanks as specified 

for EPA Method 537 (perfluorinated chemicals) for added quality control to produce results 

reflective of the source sampled. Under UCMR3, sample collection tasks for hormones and 

perfluorinated chemicals will require enhanced water utility oversight, training, and quality assurance 

practices in the field to avoid false positives. Providing 60 days to review and approve laboratory 

posted UCMR data is appropriate and provides adequate time to resolve issues with the analyzing 

laboratory. The basis provided in the UCMR3 document (FR page 11723) for shortening the water 

utility review time to 30 days (50% reduction) is "to help ensure that monitoring and reporting is 

conducted as scheduled." As discussed in Section 4.1 under the "Laboratory Reporting Schedule," 

shortening the reporting schedule does not ensure meeting scheduled SDWARS monitoring dates 

nor provide benefit to the states or EPA to receive data 30 days sooner. OCWD recommends that 
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UCMR3 maintain the same 60 day review and approval schedule for PWS as provided for UCMR1 

and UCMR2.

Response: Please see response to comment code 23820 PWS Review Time.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31880

Comment Code: 23820

Comment: 4.2 Water System Review and Approve Laboratory Data Schedule 

ACWA does not support a reduction for water systems to review, approve and report data from 60 

days to 30 days (FR pages 11717 Exhibit 2, 11723, and 141.35 (c)(5)(vi)). Water utilities faced 

significant challenges with oversight, management and coordination of UCMR2 tasks, including 

coordination with field personnel and laboratories for source sampling and delivery of samples to 

the analyzing laboratory. Implementation of the UCMR2 program was in addition to managing their 

water system’s operation, maintenance, and routine source and distribution system compliance 

monitoring and reporting requirements. New for UCMR3 is the requirement to collect field blanks 

as specified for EPA Method 537 (perfluorinated chemicals) for added quality control to produce 

results reflective of the source sampled. Under UCMR3, sample collection tasks for hormones and 

perfluorinated chemicals will require enhanced water utility oversight, training, and quality assurance 

practices in the field to avoid false positives. Providing 60 days to review and approve laboratory 

posted UCMR data is appropriate and provides adequate buffer time to resolve issues with the 

analyzing laboratory. The basis provided in the UCMR3 document (FR page 11723) for shortening 

the water utility review time to 30 days (50% reduction) is "to help ensure that monitoring and 

reporting is conducted as scheduled." As discussed in Section 4.1 under the "Laboratory Reporting 

Schedule," shortening the reporting schedule does not ensure meeting scheduled SDWARS 

monitoring dates nor provide benefit to the states or EPA to receive data 30 days sooner.

Response: Please see response to comment code 23820 PWS Review Time.

Commenter Name: Yone Akagi

Commenter Organization: City of Portland, Oregon 

Letter ID: 0088

Comment ID: 32000

Comment Code: 23820

Comment: 3. EPA has proposed changes to the reporting schedule that would reduce time for 

systems to review and report data (30 days)

Portland believes that 30 days should be sufficient time to review the laboratory data, provided that 

the laboratories or the EPA are required to notify water systems when there is data to review. 

Otherwise, we believe 45 to 60 days would be preferable.
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Response: Please see response to comment code 23820 PWS Review Time.
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Comment Code: 24000 Reporting System/SDWARS

Summary Response to Comments on Reporting System/SDWARS: EPA is committed to prepopulating the UCMR 3 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. 

In addition, EPA has taken commenter suggestions into consideration for SDWARS 3 development. 

Individual Comments

Commenter Name: Daniel J. Caldwell

Commenter Organization: Johnson&Johnson 

Letter ID: 0057

Comment ID: 31642

Comment Code: 24000

Comment: EPA should ensure that the reporting of the magnitude and frequency of measured 

concentrations of all substances adhere to scientific data management and reporting practices. Data 

reporting issues need to be clearly addressed to justify any future exposure and assessment reporting 

for further regulatory action on the substances listed on the OCMR rule and any CCL in the future.

Response: Please see response to comment code 24000 Reporting System/SDWARS.

Commenter Name:

Commenter Organization: Northern Kentucky Water District

Letter ID: 0060

Comment ID: 31646

Comment Code: 24000

Comment: With regards to the "Reporting monitoring results" (141.35 (c )(6) and 141.35 (d)(2)) 

requiring small and large systems to report all data elements in Table 1 with each sample, it would be 

very helpful if elements that are duplicated for each sample would be automatically prefilled in each 

field once the information was entered the first time. This would save significant time on data entry 

and clerical errors.

Response: Please see response to comment code 24000 Reporting System/SDWARS.
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Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31719

Comment Code: 24000

Comment: 2. UCMR Source Inventory. It is not clear whether the Safe Drinking Water Accession 

and Review System (SDWARS) source water inventory database will be pre-populated with UCMR2 

monitoring locations and PWS information or if water agencies will be required to enter all new 

PWS information for UCMR3. CVWD recommends that the SDWARS database be pre populated 

with UCMR2 monitoring locations and PWS information to benefit from the significant amount of 

work completed for this previous monitoring program. Much of the information entered for 

UCMR2 monitoring plans will remain the same or only require minor revisions for most PWSs.

Response: Please see response to comment code 24000 Reporting System/SDWARS.

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31761

Comment Code: 24000

Comment: 2. UCMR Source Inventory. It is not clear whether the Safe Drinking Water Accession 

and Review System (SDWARS) source water inventory database will be pre-populated with UCMR2 

monitoring locations and PWS information or if water agencies will be required to enter all new 

PWS information for UCMR3. WESTCAS recommends that the SDWARS database be prepopulated with UCMR2 monitoring locations and PWS information to benefit from the significant 

amount of work completed for this previous monitoring program. Much of the information entered 

for UCMR2 monitoring plans will remain the same or only require minor revisions for most PWSs.

Response: Please see response to comment code 24000 Reporting System/SDWARS.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31775

Comment Code: 24000

Comment: 9. Revised data elements (sampling point ID code established by state or at state 

discretion, provided by PWS)

AMWA supports including an additional sampling point ID code as provided by the PWS. Many 

large utilities are likely to already have state approved sampling point ID codes and it is critical that 

EPA and the states allow the use of these codes rather than add additional data points that need to 

be checked by requiring a new code.
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Response: Please see response to comment code 24000 Reporting System/SDWARS.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD) 

Letter ID: 0052

Comment ID: 31844

Comment Code: 24000

Other EPA Comment Codes and Descriptions: 23300 Ground Water Representative Monitoring 

Locations 

Comment: 2.0 Sample Location and Inventory Information: Representative Locations and Use of 

UCMR2 Approved Sites 

UCMR2 pre-populated the water system’s sources into SDWARS and required water systems to 

review and revise source locations and inventory information 240 days after date of publication of 

the final rule (i.e., August 2, 2007 for UCMR2). EPA acknowledged that the pre-populated UCMR2 

SDWARS database used water system information that were several years old and required verifying, 

correcting, and updating system data elements. Water utilities expended significant time and

resources with review and editing activities for UCMR2 implementation to ensure that the 

SDWARS inventory was accurate for source water entry points to the distribution system (EPTDS; 

after treatment, if appropriate) and included the newly required sampling location at the distribution 

system maximum residence time (DSMRT). Additionally, using state and/or EPA approved 

UCMR2 groundwater representative sampling locations or approved representative treated import

wholesale connections will (1) avoid duplicating the regulatory review and approval process for 

UCMR3, (2) avoid re-entering source inventory information (groundwater and treated import water 

sources representative wholesaler connections), and (3) increase efficiency with UCMR3 

documentation tasks into the SDWARS database.

The SDWARS UCMR2 Source Inventory database needs to be kept in place as the "starting point or 

template" for water systems to review and revise for UCMR3. The majority of water system’s source 

inventory, both the EPTDS and DSMRT locations, will remain the same and may require minimal 

revision to (1) remove locations no longer in use (e.g., destroyed drinking water wells), (2) add new 

sources (e.g., new drinking water wells, new treatment points, new import connection from a 

wholesaler, etc.), or (3) add new UCMR3 data elements for sample sources not previously required 

for UCMR2. Under UCMR2, many water utilities monitored a representative treated import 

wholesale connection (e.g., CA treated surface water provided by major wholesaler to downstream 

water utilities via wholesale connections) quarterly at sampling locations that were approved by the 

EPA Regional office. These approved UCMR2 "representative wholesale connections" should be 

approved for UCMR3 if no changes have occurred within the water system. EPA acknowledges that 

water systems may purchase water from a wholesaler via multiple connections but are permitted to 

use a representative wholesale connection for compliance monitoring under UCMR3 (FR 

pages11721, 11722 and 141.40(a)(3) Table 1 ). Additionally, representative groundwater monitoring 

plans approved for UCMR2 should be applicable for UCMR3 if no changes occurred within the 

water system’s groundwater sources. UCMR3 indicates that after rule publication, PWSs will develop 

monitoring plans and enter sample information into the SDWARS source inventory database (FR 

pages 11722 Exhibit 4, 11723, 141.35(c)(2) and 141.35(c)(3)); however, there is no reference to use 

the existing UCMR2 SDWARS source inventory as the template to identify sources and develop the 
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UCMR3 monitoring plans. OCWD recommends that use of the UCMR2 SDWARS pre-populated 

source inventory as the "starting template" be described and included in the rule’s regulatory 

language.

Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31846

Comment Code: 24000

Other EPA Comment Codes and Descriptions: 23300 Ground Water Representative Monitoring 

Locations 

Comment: 3.3 Data Elements Reported with All Sample Results

EPA is proposing specific data elements be reported for each sampling event. The preamble and 

regulatory language does not provide sufficient details on "how, when, where and who" enters the 

data elements with each posted result. OCWD is very concerned how this information will be 

provided/entered for the UCMR3 program. EPA needs to evaluate the current SDWARS data entry 

format used for UCMR1 and UCMR2 and avoid the need to re-enter duplicate information for each 

sample point for each sampling event. As discussed in Section 2.0 above, EPA needs to streamline 

the SDWARS database entry steps to minimize duplication of re-entering the "same" information 

that was previously provided for UCMR2 or will be provided in the revised PWS’s upcoming 

UCMR3 source inventory data elements. Lessons learned from the UCMR2 program will save time, 

avoid double entry of information, and potentially avoid data entry errors. Recommendations to 

improve and streamline the UCMR3 SDWARS database entry activities include the following: 

* All required source identification information be entered once at the time of establishing the 

UCMR3 source inventory (under UCMR2, source information was entered before the on-set of the 

monitoring period). 

* UCMR3 SDWARS source inventory should begin with the same sites entered for UCMR2 (see 

Section 2.0 for discussion) as the "template" for PWSs to review and revise, as needed. This avoids 

re-entering duplicate information. 

* UCMR2 approved groundwater and wholesale representative sites, should be approved for 

UCMR3 as entered in SDWARS and used as the "starting template" for UCMR3 for PWSs to

review and revise, as warranted.

* The source inventory screen in SDWARS should be open and available for review and revision for 

all sources for a PWS. Presently, only one source is "open" for review, revision, or to add site notes. 

The screen must be closed and the next source is selected to be "opened" for review, edit or to add 

notes. The individual source entry process it too time consuming and requires duplicating same 

information for List 1 and List 2 for the same source (for the draft UCMR3, there are no List 2 
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chemicals so this will not be an issue but a consideration should the final UCMR3 have a List 1 and 

List 2 chemicals).

Response: Please see response to comment codes 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31876

Comment Code: 24000

Other EPA Comment Codes and Descriptions: 23300 Ground Water Representative Monitoring 

Locations 

Comment: 2.0 Sample Location and Inventory Information: Representative Locations and Use of 

UCMR2 Approved Sites 

UCMR2 pre-populated the water system’s sources into SDWARS and required water systems to 

review and revise source locations and inventory information 240 days after date of publication of 

the final rule (i.e., August 2, 2007 for UCMR2). EPA acknowledged that the pre-populated UCMR2 

SDWARS database used water system information that were several years old and required verifying, 

correcting and updating system data elements. Water utilities expended significant time and

resources with review and editing activities for UCMR2 implementation to ensure that the 

SDWARS inventory was accurate for source water entry points to the distribution system (EPTDS; 

after treatment, if appropriate) and included the newly required sampling location at the distribution 

system maximum residence time (DSMRT). Additionally, using state and/or EPA approved 

UCMR2 groundwater representative sampling locations or approved representative treated import

wholesale connections will (1) avoid duplicating the regulatory review and approval process for 

UCMR3, (2) avoid re-entering source inventory information (groundwater and treated import water 

sources), and (3) increase efficiency with UCMR3 documentation tasks into the SDWARS database. 

The SDWARS UCMR2 Source Inventory database needs to be kept in place as the "starting point or 

template" for water systems to review and revise for UCMR3. The majority of water system’s source 

inventory, both the EPTDS and DSMRT locations, will remain the same and may require minimal 

revision to (1) remove locations no longer in use (e.g., destroyed drinking water wells), (2) add new 

sources (e.g., new drinking water wells, new treatment points, new import connection from a 

wholesaler, etc.), or (3) add new UCMR3 data elements for sample sources not previously required 

for UCMR2. Under UCMR2, many water utilities monitored a representative treated import 

wholesale connection (e.g., CA treated surface water provided by major wholesaler to downstream 

water utilities via wholesale connections) quarterly at sampling locations that were approved by the 

EPA Regional office. These approved UCMR2 "representative wholesale connections" should be 

approved for UCMR3 if no changes have occurred within the water system. EPA acknowledges that 

water systems may purchase water from a wholesaler via multiple connections but are permitted to 

use a representative wholesale connection for compliance monitoring under UCMR3 (FR 

pages11721, 11722 and 141.40(a)(3) Table 1 ). Additionally, representative groundwater monitoring 

plans approved for UCMR2 should be applicable for UCMR3 if no changes occurred within the 

water system’s groundwater sources.
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UCMR3 indicates that after rule publication, PWSs will develop monitoring plans and enter sample 

information into the SDWARS source inventory database (FR pages 11722 Exhibit 4, 11723, 

141.35(c)(2) and 141.35(c)(3)); however, there is no reference to use the existing UCMR2 SDWARS 

source inventory as the template to identify sources and develop the UCMR3 monitoring plans. 

ACWA recommends that use of the UCMR2 SDWARS pre-populated source inventory as the 

"starting template" be described and included in the rule’s regulatory language. 

Response: Please see response to comment codes 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31878

Comment Code: 24000

Other EPA Comment Codes and Descriptions: 23300 Ground Water Representative Monitoring 

Locations 

Comment: 3.3 Data Elements Reported with All Sample Results

EPA is proposing specific data elements be reported for each sampling event. The preamble and 

regulatory language does not provide sufficient details on "how, when, where and who" enters the 

data elements with each posted result. ACWA is very concerned how this information will be 

provided/entered for the UCMR3 program. EPA needs to evaluate the current SDWARS data entry 

format used for UCMR1 and UCMR2 and avoid the need to re-enter duplicate information for each 

sample point for each sampling event. As discussed in Section 2.0 above, EPA needs to streamline 

the SDWARS database entry steps to minimize duplication of re-entering the "same" information 

that was previously provided for UCMR2 or will be provided in the revised PWS’s upcoming 

UCMR3 source inventory data elements. Lessons learned from the UCMR2 program will save time, 

avoid double entry of information, and potentially avoid data entry errors. Recommendations to 

improve and streamline the UCMR3 SDWARS database entry activities include the following: 

*All required source identification information be entered once at the time of establishing the 

UCMR3 source inventory (under UCMR2, source information was entered before the on-set of 

monitoring period). 

* UCMR3 SDWARS source inventory should begin with the same sites entered for UCMR2 (see 

Section 2.0 for discussion) as the "template" for PWSs to review and revise, as needed. This avoids 

re-entering duplicate information. 

*UCMR2 approved groundwater and wholesale representative sites, should be approved for 

UCMR3 as entered in SDWARS and used as the "starting template" for UCMR3 for PWSs to 

review and revise, as warranted.

*The source inventory screen in SDWARS should be open and available for review and revision for 

all sources for a PWS. Presently, only one source is "open" for review, revision, or to add site notes. 
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The screen must be closed and the next source is selected to be "opened" for review, edit or to add 

notes. The individual source entry process it too time consuming and requires duplicating same 

information for List 1 and List 2 for the same source (for the draft UCMR3, there are no List 2 

chemicals so this will not be an issue but a consideration should the final UCMR3 have a List 1 and 

List 2 chemicals).

Response: Please see response to comment code 23300 Ground Water Representative Monitoring 

Locations and 24000 Reporting System/SDWARS.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32098

Comment Code: 24000

Comment: 10.Requir[ing] systems to report all data elements with each sample. The data elements 

are generally appropriate and the burden would be reasonable if the electronic data system is well 

crafted. Numerous examples of EPA data systems exist that require repeated re-keying of 

information that: 

1. Increase the burden of data entry to a debilitating extreme, and

2. Increase the number of errors in the resulting database because the same or very similar 

information must be repeatedly re-entered.

The electronic data system should be designed for the ready upload of preformatted information 

(e.g., files generated in Excel and LIMS systems), or allow for copying of fields from previous entries 

when data is submitted or edited in the EPA on-line data system. To the extent possible, data 

elements that are common to multiple samples should not have to be re-keyed each time a sample is 

recorded. 

EPA’s description of what is expected for data entry is not clear in the Federal Register notice, so 

the current notice does not clearly communicate the burden involved. Personal communication with 

EPA staff suggests that the agency anticipates a more efficient and effective data system than is 

presented in the notice.[FN20: Hautman, Personal communication, telephone conversation on 

questions of clarification regarding the UCMR3 notice, April 8, 2011.] In collecting all of the data 

elements with each sample, the agency should not expect the water system or laboratory to update 

each of the data fields (e.g., population served, disinfectant used, zip codes served, etc.) associated 

with that specific observation. If this information were required, then the burden associated with the 

approach as stated in the notice would be substantial as it would require the system to estimate 

seasonal shifts in population, estimate the area of influence associated with individual EPTDS or 

DSMRT observations reflect (in terms of zip codes served). Also, such an approach would require 

substantial interaction between the systems that purchase water and their wholesale supplier. A 

dialogue between the agency, water systems, and the laboratories could identify data system 

requirements that would minimize data entry challenges and facilitate quality assurance and quality 

control procedures. 
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Response: Please see response to comment code 24000 Reporting System/SDWARS. 
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Comment Code: 30000 Potential UCMR 3 Contaminants

Summary Response to Comments on Potential UCMR 3 Contaminants: The 1996 

amendments to SDWA instituted the Contaminant Candidate List (CCL) and UCMR programs to 

provide information EPA needs to determine which drinking water contaminants have the greatest 

potential to present a meaningful opportunity to reduce health risk through a national primary 

drinking water regulation (NPDWR). The CCL is the primary mechanism for the identification of 

contaminants that may require regulation while UCMR provides EPA with the data necessary to 

determine if a contaminant occurs at a frequency and concentration that would be a public health 

concern. The CCL and UCMR are coordinated parts of EPA's risk management process, and they 

support each other. 

In establishing its proposed list of contaminants for UCMR 3, EPA used a stepwise prioritization 

process similar to the process used for UCMR 1 and 2. As a first step, the agency reviewed the 

recently promulgated CCL 3 and the "pre-CCL" contaminants considered in the development of 

CCL 3. Under the CCL 3 process, the agency considered the best available data and information on 

health effects and occurrence to evaluate 7,500 unregulated contaminants. The final CCL 3 is 

comprised of 104 chemicals or chemical groups and 12 microbiological contaminants that were 

selected through a data-driven process that considered adverse health effects (potency and severity) 

and occurrence (prevalence and magnitude). The list includes pesticides, biological toxins, 

disinfection byproducts, chemicals used in commerce, and waterborne pathogens (74 FR 51850, 

October 8, 2009). EPA used CCL 3, along with additional sources of information about other 

emerging contaminants of concern, to establish an initial list of almost 150 potential UCMR 3 

contaminants. 

The document "UCMR 3 Contaminants - Information Compendium" (available on regulations.gov) 

Appendix B, "Initial List of Contaminants Considered for UCMR 3", presents the initial list of 

contaminants that EPA considered, and includes indicators for which contaminants were listed as 

part of CCL 3 or other CCL/UCMR lists. The last column of the Appendix B table indicates the 

reason each contaminant was eliminated, if applicable. The proposed contaminant list for UCMR 3 

was pared down as follows: (1) contaminants with no currently available methods, or methods that 

would not be ready in time for UCMR 3 monitoring, were eliminated and (2) those contaminants 

included in UCMR 1 or UCMR 2 monitoring were eliminated from inclusion. This narrowed list of 

fewer than 35 analytes was further considered by an EPA and State working group, and prioritized 

using health effects data and other critical endpoints, to arrive at a proposed list of 30 analytes. EPA 

published this proposed list in the Federal Register on March 3, 2011 (76 FR 11713). Further 

information on this prioritization process and on the health effects and occurrence data EPA used 

to select the chemical analytes proposed for UCMR 3 is contained in "UCMR 3 Contaminants - 

Information Compendium." After receiving and considering public comments on the proposed list, 

EPA has added chromium-6 to the list of unregulated contaminants, and removed sec-butylbenzene 

and n-propylbenzene. Pursuant to Section 1445(a)(1)(A) of SDWA, as amended in 1996, EPA is also 

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

Individual Comments

Commenter Name: Diane VanDe Hei
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Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31596

Comment Code: 30000

Comment: May 2, 2011

Water Docket United States Environmental Protection Agency 1200 Pennsylvania Avenue, NW, 

Mail Code 282211T Washington, DC 20460

Re: Docket ID No. OW-2009-0090, Unregulated Contaminant Monitoring Regulation (UCMR 3) 

Proposed Rule, 76 FR 11715

Dear Water Docket:

The Association of Metropolitan Water Agencies (AMWA) appreciates the opportunity to comment 

on the proposed Unregulated Contaminant Monitoring Regulation (UCMR-3). AMWA is an 

organization of the CEOs and directors of the largest publicly owned drinking water providers in 

the United States. Collectively, AMWA member utilities serve the drinking water needs of more than

130 million people. AMWA is committed to working with EPA to ensure safe and cost-effective 

federal drinking water regulations.

In general AMWA supports EPA’s proposed list of contaminants, but has several recommendations 

to offer regarding analytical methods, revised data elements to be reported and the use of these data 

elements for additional occurrence and exposure analyses. AMWA also recommends that EPA 

include hexavalent chromium (Cr(VI)) in UCMR-3 if the agency can clearly state that Cr(VI) poses a

significant public health risk at the low levels likely to be found in finished drinking water. 

The attached comments provide responses to 16 specific issues and requests for comment raised in 

EPA’s proposal. AMWA also provides an additional recommendation regarding how EPA should 

consider the UCMR in light of its drinking water strategy.

If there are any questions about AMWA’s comments, please contact me or Erica Brown, AMWA’s 

Director of Regulatory Affairs and Scientific Program Development and 202-331-2820.

Sincerely,

Diane VanDe Hei Executive Director

Attachment

Cc: Cynthia Dougherty, OGWDW Pam Barr, OGWDW

Association of Metropolitan Water Agencies Comments on the Unregulated Contaminant 

Monitoring Regulation (UCMR -3) Proposed Rule, 76 FR 11715

May 2, 2011
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 AMWA’s comments provide responses to 16 specific issues and requests for comment raised in 

EPA’s proposal. AMWA also provides an additional recommendation about how EPA should 

consider the UCMR in light of its drinking water strategy. 

Responses to EPA Request for Comment 

1. Proposed List of Contaminants 

In general, AMWA supports EPA’s proposed list of contaminants with the following observations 

and recommendations: 

* Compounds that are not included on the Contaminant Candidate List (CCL) should not be moved 

to the UCMR without sufficient justification, such as posing a significant risk to public health. 

* In general, contaminants covered by existing or proposed regulations should not be included on 

the UCMR; there are existing protocols (e.g., ICR) for updating source and occurrence information 

on contaminants that are already covered by existing or proposed regulations. 

Response: Please see response to comment codes 30000 Potential UCMR 3 Contaminants, 38100 

Chromium-6, and 38200 Total Chromium.

Commenter Name: David Chang 

Commenter Organization: Golden State Water Company (GSWC)

Letter ID: 0054

Comment ID: 31628

Comment Code: 30000

Comment: * GSWC believes EPA should broaden its outreach to make sure the 30 chemicals 

selected are the most important with known health risks. The monitoring will fill the data gaps to 

make informed regulatory determinations. Accordingly, EPA should document inputs received from 

stakeholders on which chemical should or should not be included and how EPA reaches its final 

decision on each chemical.

Response: Please see response to comment code 30000 Potential UCMR 3 Contaminants.

Commenter Name: Phillip W. Holderness 

Commenter Organization: California-Nevada Section, American Water Works Association (CANV AWWA)

Letter ID: 0055

Comment ID: 31634

Comment Code: 30000

Comment: * CA-NV AWWA believes EPA should broaden its outreach to make sure the 30 

chemicals selected are the most important with known health risks. The monitoring will fill the data 

gaps to make infonned regulatory determinations. Accordingly, EPA should document inputs 
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received from stakeholders on which chemical should or should not be included and how EPA 

reaches its final decision on each chemical.

Response: Please see response to comment code 30000 Potential UCMR 3 Contaminants.

Commenter Name: Daniel J. Caldwell

Commenter Organization: Johnson&Johnson 

Letter ID: 0057

Comment ID: 31643

Comment Code: 30000

Comment: EPA has included the several substances on the proposed UCMR3 analyte list based on 

EPA’s Information Compendium. In the "background" information reported for several substances 

shows some references [FN6: Kolpin, et al. 2002. Environ. Sci. Technol. 36 (6): 1202-1211] that 

have over reported median values used to justify widespread exposure. While some of the references 

do provide a significant contribution toward the understanding of the occurrence of compounds, 

such as personal care products and pharmaceuticals, following their intended use, we would like to 

comment on two points that are scientifically important and would be of value to EPA and the 

general public. In the Kolpin paper there were some unintended reporting bias issues that needs to 

be understood and avoided in the future. The issues are: 

(i) Reporting a median concentration for only those samples where analytes were detected; and

(ii) The inclusion of data with reported concentrations of target contaminants in field blanks (see 

above comments) 

Without clear adherence to scientific data management and reporting practices, results of reported 

median values will suggest concentrations of a substance in the environment that is significantly 

higher than actually detected.

Response: Please see response to comment code 30000 Potential UCMR 3 Contaminants.

EPA agrees that adherence to scientific data management and reporting practices is essential. EPA 

notes that this is the very reason that the UCMR program requires the use of only UCMR approved 

laboratories, that laboratories must follow a strict set of analytical quality control and reporting 

requirements, that all data are reported electronically directly from the laboratories themselves, and 

that all laboratories are subject to audit throughout the UCMR monitoring period. These and other 

laboratory and reporting requirements and EPA oversight assure the quality of UCMR data, which is 

the primary source of occurrence data used by EPA to make decisions concerning possible future 

regulations. 

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31821

Comment Code: 30000
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Comment: Contaminants 

Assessment chemical analytes

Title 40 Code of Federal Regulations (40 CFR) 141.40(a)(3) proposes a list of 28 chemical priority 

contaminants, with 6 EPA-developed and 4 consensus organization developed analytical methods, 

as well as new monitoring dates of January 2013 through December 2015. EPA used a stepwise 

CCL prioritization process to identify potential UCMR 3 contaminants. Under the CCL 3 process, 

the EPA considered the best available data and information on health effects and occurrence to 

evaluate 7,500 unregulated contaminants. 

The TCEQ generally supports the prioritization process. 

Thirty UCMR3 Contaminants [Table: See PDF Docket ID: EPA-HQ-OW-2009-0090-0087.2]

Response: Please see response to comment code 30000 Potential UCMR 3 Contaminants.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31863

Comment Code: 30000

Comment: Association of State Drinking Water Administrators May 2, 2011

Comments on the Unregulated Contaminant Monitoring Rule - third cycle (UCMR3)

The Association of State Drinking Water Administrators (ASDWA) appreciates the opportunity to 

comment on the U.S. Environmental Protection Agency’s (EPA) proposed revisions to the 

Unregulated Contaminant Monitoring Rule - third cycle (UCMR3) published in the Federal Register 

on March 3, 2011 (Vol. 76, No. 42). Even though this is a direct implementation rule, ASDWA feels 

it is an important rule that deserves state attention, especially since many states partner with EPA on 

implementation of the UCMR. The proposed revisions will, in our view, improve implementation of 

the UCMR. States that have partnered with EPA on implementation of the UCMRs over the years 

appreciate the improvements EPA has made in each new UCMR to help make the process easier to 

implement. These improvements benefit the water systems covered by the rule and the states that

assist them; and it encourages states to continue these partnerships. 

Overall, the UCMR3 appears to provide an appropriate list of contaminants for monitoring that is 

reflective of the work done through the Contaminant Candidate List process. It should provide the 

additional occurrence information needed to assist EPA in making a determination of whether to 

regulate a contaminant in the interest of protecting public health. While there is nothing inherently 

wrong with the current list of contaminants, there are areas where changes could be made to meet 

high priority needs for data on current "hot issues" and other minor changes that would improve the 

rule.
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ASDWA offers the following comments on the proposed UCMR3 and specifically on the potential 

inclusion of chromium-6. Comments are organized according to the specific requests for comment 

outlined in the preamble. 

Page 11716: "In addition to requesting comment on the proposed list of contaminants, EPA also 

requests comment on: Monitoring based on retail population; revised data elements; and other 

changes between UCMR 2 and UCMR 3 that are outlined in Exhibit 2. Updates to Web addresses, 

applicability dates, corrections of minor typographical errors, and other minor clerical edits are 

reflected in rule language, but do not appear in Exhibit 2." 

Proposed list of contaminants - ASDWA has some additional contaminants to be considered for 

UCMR3 (chromium is addressed separately below).

* Cyanobacteria: In the past year, Ohio and many other states have experienced major algae blooms 

(cyanobacteria) in some of their surface water sources. This has raised the awareness of the states, 

water systems, and the public of cyanotoxins such as microcystin in source waters and their potential 

for effects on public health. It may be time for a more comprehensive look at the occurrence of 

these cyanotoxins nationally so that appropriate controls can be considered. The data may also point 

to control of the contamination sources rather than through more traditional regulatory approaches. 

Response: Please see response to comment code 30000 Potential UCMR 3 Contaminants.

EPA agrees that it is important to obtain occurrence data on cyanotoxins. However, at this time, 

EPA has been unable to find or develop an analytical method appropriate to the needs of the 

UCMR program. EPA continues to conduct cyanotoxin analytical methods development research. 

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31886

Comment Code: 30000

Comment: May 2, 2011

Water Docket United States Environmental Protection Agency Mail Code 282211T, 1200 

Pennsylvania Avenue, NW. Washington, DC 20460 Attention Docket ID No. OW-2009-0090

Re: Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public Water 

Supplies (FR 76: 11713-11737, March 3, 2011)

To Whom It May Concern: 

The New Jersey Department of Environmental Protection (NJDEP) is pleased to comment on the 

Proposed Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) published on 

March 3, 2011 (FR 76: 11713-11737, March 3, 2011). The proposed UCMR3 monitoring is 

scheduled to take place between 2013 and 2015, and the analysis of the data will take place in 2016. 

The NJDEP is providing comments and information on analysis, monitoring, and occurrence on 

some of the contaminants listed in the proposed UCMR3 in order to provide constructive input to 
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the USEPA’s effort to gather national data. NJDEP recognizes that these UCMR3 data will be 

evaluated along with other information as part of future regulatory decisions by USEPA regarding 

the development of Maximum Contaminant Levels. The NJDEP understands that potential future 

development of Maximum Contaminant Levels (MCLs) by New Jersey and/or USEPA will be 

accomplished subsequent to review of available monitoring data, and would be based on the best 

available toxicological and science information.

The NJDEP generally supports the candidate chemicals and viruses selected by the United States 

Environmental Protection Agency (USEPA) for national monitoring in drinking water systems listed 

in the proposed UCMR3. Some of the candidate contaminants have been detected in New Jersey 

drinking water systems and the occurrence information collected through the UCMR3 will further 

our understanding of which drinking water contaminants occur at frequencies and concentrations of 

public health concern. 

Response: Please see response to comment code 30000 Potential UCMR 3 Contaminants. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32051

Comment Code: 30000

Comment: EPA Requests for Comment in UMCR3 Notice

1. Requesting comment on the proposed list of contaminants. 

AWWA strongly supports a close tie between the proposed UCMR3 analytes and the Third 

Contaminant Candidate List (CCL3) contaminants. Almost all the UCMR3 analytes were on CCL3, 

with the exceptions of the hormones and perfluorinated compounds that are captured by the 

proposed UCMR3 methods. This consistency with the SDWA framework is heartening. As pointed 

out in our comments following the stakeholder meeting, while the analytes selected are from the 

CCL3, there is little consistency with the data gaps (e.g., analytical method, occurrence, and health 

effect science) identified in the CCL3 notice.[FN6: 74 Federal Register 51859 (Exhibit 2)] The 

selection of UCMR3 analytes does not show any clear preference to those believed to be the more 

toxic among the CCL3 contaminants.[FN7: 2009, EPA, Contaminant Information Sheets for the 

Final CCL 3 Chemicals, EPA 815-R-09-012.]

The agency should be aware that there is little reason to believe UCMR3 will document occurrence 

at concentrations that are health relevant for three of the CCL3 contaminants: methyl chloride, 1,3 -

butadiene and chlorodifluoromethane. These analytes are gases with boiling points below 0°C. This 

observation is relevant; the two previous cycles of UCMR monitoring found very limited observed 

occurrence of tested analytes. UCMR1 led to detections of eight analytes out of the 24 monitored. 

Three of the detected compounds in UCMR1 were only observed once; two analytes, perchlorate 

and monomethyl tetrachloroterephthalate /tetrachloroterephthalic acid, accounted for the 

overwhelming majority of detections. EPA’s most recent summary of UCMR2 indicates that 13 of 

the 25 UCMR2 analytes were not detected at levels greater than the method reporting 

level.[FN8:2010, EPA, Second Cycle of the Unregulated Contaminant Monitoring Regulation 
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(UCMR2). October, 2010.] A better prioritization process (with stakeholder input) is needed for 

future UCMRs to improve the number of detected compounds. 

Response: Please see response to comment code 30000 Potential UCMR 3 Contaminants.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32074

Comment Code: 30000

Comment: 5. EPA requests comments on if the proposed analytical methods are appropriate. 

EPA proposed the methods in the following table. Table 2. Proposed UCMR List 1 Analytical 

Methods [See PDF Docket ID: EPA-HQ-OW-2009-0090-0080.1]

EPA Methods 200.8, and 300.1; ASTM D5673-10 and D6581-08; and Standard Methods 3125 and 

4110D are in widespread application and their performance is well understood. There is limited data 

to evaluate the likely performance of the remaining methods.

Response: EPA believes that there are appropriate data with which to evaluate the performance of 

the remaining methods. In every case, EPA conducted rigorous, multi-year research into all aspects 

of each analytical method. Following the successful completion of these research projects, each 

analytical method was peer reviewed by scientists both within and outside of EPA. In addition, each 

method was extensively demonstrated in at least one non-EPA laboratory and then LCMRLs were 

determined by at least three and in some cases as many as 9 laboratories. In addition, before any 

laboratory is permitted to report UCMR data, it must successfully complete the UCMR laboratory 

approval process, which includes an Initial Demonstration of Capabilities. This includes determining 

precision and accuracy for each analyte, and the successful analysis of an EPA supplied performance 

testing sample. EPA is confident of the performance of all analytical methods proposed for UCMR 

monitoring. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080

Comment ID: 32088

Comment Code: 30000

Comment: Recommended MRLs - The following table reflects the appropriate MRLs for use in 

UCMR3 based on available information regarding method performance, 

Table 3. Appropriate MRLs for Proposed UCMR List 1 Analytes [See PDF Docket ID: EPA-HQOW-2009-0090-0080.1]

While the proposed MRLs for non-CCL3 analytes are inappropriately low because they are based 

solely on the LCMRL, these do represent a challenging group of contaminants for which to set a 
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MRL based on information in the docket. At a minimum, it is unreasonable to set the MRL for 

these compounds at a level that is lower than any of the UCMR3 analytes in the same method for 

which there is a strong record in the CCL3 and UCMR3 dockets. There are two approaches - one 

can either a) set the MRL for these analytes greater than or equal to the highest of the LCMRLs for 

the other method analytes or b) base the MRL on the HRL derived MRLs such that it is no lower 

than the lowest proposed MRL when using a factor of the HRL to determine the appropriate MRL 

for UCMR3 analytes in the same method. 

Response: Please see response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32090

Comment Code: 30000

Comment: Appropriate Sampling Location(s) EPA proposes to monitor each group of targeted 

UCMR3 analytes at a consistent set of monitoring locations. AWWA agrees with this approach as it 

facilitates sampling logistics and subsequent analysis of the UCMR3 data. The monitoring locations 

are reflected in the following table.

Table 4. UCMR List 1 Monitoring Locations [See PDF Docket ID: EPA-HQ- OW-2009-0090-

0080.1] [76 FR 11723]

The agency did not provide a specific rationale for using the default UCMR monitoring location for 

hormones, VOCs, SOCs, and perfluorinated compounds. AWWA agrees with the agency that the 

EPTDS monitoring location is a sound sampling location for each of these groups of analytes. The 

primary concern with these analytes is their presence in source water, passing through treatment, 

and into the finished water. Significant increase in the concentration of these analytes is not 

expected in the distribution system. 

Response: EPA agrees that the EPTDS is the correct place for UCMR 3 monitoring of these 

compounds. Also, since they are not likely to be significantly impacted by their time in the 

distribution system, it is not necessary to also monitor them there. 

Please see response to comment code 30000 Potential UCMR 3 Contaminants.
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Comment Code: 31000 Hormones

Summary Response to Comments on Hormones: EPA believes that monitoring for the selected 

hormones is justified. EPA has concluded that seven hormones (17 alpha-estradiol, 17 betaestradiol, equilenin, equilin, estriol, estrone, and ethinyl estradiol) should be included in UCMR 3 

monitoring because these contaminants are known or anticipated to occur in public water systems at 

levels of health concern; however, there is insufficient occurrence data available to permit EPA to 

make an informed regulatory determination at this time.

In the final rule, EPA has moved the hormone monitoring requirement from Assessment 

Monitoring (List 1) to Screening Survey (List 2). This change will substantially reduce the number of 

PWSs that are required to monitor for hormones and mitigate any concerns regarding laboratory 

capacity. EPA has addressed concerns regarding sample contamination by requiring the collection of 

field blank samples and the use of nitrile gloves during collection and handling, as detailed in the 

UCMR 3 Laboratory Approval Requirements and Information Document. In addition, EPA 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. 

EPA selected sec-butylbenzene and n-propylbenzene, non-carcinogenic VOCs, for removal after 

considering data submitted by states that indicated very low occurrence rates. EPA also considered 

the fact that the currently available health reference levels, 10.3 μg/L and 5.83 μg/L, respectively, are 

well above the reported levels of occurrence in these data. Chromium-6 (hexavalent chromium) and 

total chromium have been added to the list of contaminants to be monitored. 

Individual Comments

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31598

Comment Code: 31000

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: - AMWA has additional concerns about EPA Method 539. Specifically, with such a low 

minimum reporting level (MRL) for this method, there is a potential for samples to be contaminated 

due to external factors or improper QA/QC techniques. 

* AMWA recommends that the analytes to be measured for EPA Method 539 be included under 

List 2, Screening Survey. As noted in our detailed comments about the analytical methods, below, 

there are many potential issues associated with the sampling protocols and analytical method 

associated with this new method and therefore, AMWA believes it is more appropriate to include 

the five hormones on CCL-3 (17alpha-estradiol, 17-beta estradiol, estriol, estrone and ethinyl 

estradiol) as List 2 analytes. AMWA recommends that EPA select the same utilities to sample for 

List 2 analytes as in previous UCMR rulemakings (i.e., systems serving more than 100,000 persons).
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Response: Please see response to comment code 31000 Hormones. 

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31619

Comment Code: 31000

Other EPA Comment Codes and Descriptions: 38000 Other Contaminants

Comment: To make room for Chromium-6, CTDPH suggests removing one of the following 

contaminants: 

3) Estrogenic and androgenic: hormones seem to have occupied 7 spots on the list. One of those 

could be removed to make room for Chromium, and possibly use bisphenol A in substitution to 

another hormone on the list.

Response: Please see response to comment codes 31000 Hormones and 38100 Chromium-6. 

Bisphenol A is not under consideration as a contaminant for monitoring in UCMR 3 because there 

is currently no appropriately validated, robust analytical method available. EPA will consider 

Bisphenol A for future monitoring. 

Commenter Name: Daniel J. Caldwell

Commenter Organization: Johnson&Johnson 

Letter ID: 0057

Comment ID: 31640

Comment Code: 31000

Comment: We are pleased to offer the following comments on the proposed Unregulated Chemical 

Monitoring Rule. 

Regards, Daniel J. Caldwell, Ph.D., DABT Principal, Environmental Toxicology Johnson&Johnson 

410 George Street New Brunswick, NJ 08901 732-524-1088

April 29, 2011 Docket ID No. OW-2009-0090 U.S. Environmental Protection Agency Mail Code 

282211T 1200 Pennsylvania Avenue, N.W. Washington, DC 20460 Re: EPA Docket ID No. OW2009-0090

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

Systems (76 Fed. Reg. 11713, March 3, 2011) Ladies and Gentlemen:

Johnson & Johnson is pleased to submit these comments on the U.S. Environmental Protection 

Agency’s (EPA) Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for 

Public Water Systems. EPA has published proposed monitoring requirements for 30 contaminants 

(76 Fed. Reg. 11713, March 3, 2011) (Proposal), most of which are on its Candidate Contaminant 
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List 3 (CCL3) that was published in 2009. The Proposal makes available for public review and

comment the proposed monitoring for evaluation of potential drinking water contaminants that 

should be investigated further for addition to the primary drinking water regulations. There are 

seven hormones, six of which are naturally occurring, that are included on proposed List 1 for 

assessment. We have carefully reviewed the Proposal and are pleased to offer these comments.

The justification for including the seven hormones selected for List 1 assessment monitoring does 

not appropriately recognize the fact that all but one occur naturally and are excreted in urine.

EPA has included the following seven hormones on the proposed UCMR3 analyte list: 17-ßestradiol, 17-a- ethynylestradiol (EE2), estriol, estrone, testosterone, 4-androstene-3,17-dione and 

equilin (76 Fed. Reg. 11718). Six of these hormones occur naturally - only EE2 is a synthetic 

hormone. EPA’s "Possible Contaminants for Inclusion on UCMR - Information Compendium" 

(EPA 815- B-10-002), hereafter referred to as the Information Compendium, describes the 

"background" for each of these hormones and lists all seven as "used in pharmaceuticals." While this 

statement is accurate, it is incomplete and misleading. In fact, the principal source of the six naturally 

occurring hormones in the effluents of publicly owned treatment works (POTWs) and surface water 

used as drinking water supplies is human and animal excretion of these chemicals.[FN1: Wise, A., 

O’Brien, K., and Woodruff, T. 2011. "Are Oral Contraceptives a Significant Contributor to the 

Estrogenicity of Drinking Water?" Env. Sci. & Technol., 45(1): 51-60.] It is misleading to the public 

and the drinking water industry to imply that the principal source of these six hormones is their use 

in pharmaceutical products. We request that EPA clarify that all of the hormones on the UCMR3 

list with the exception of EE2 are naturally occurring, in addition to their use in pharmaceuticals.

The Agency states that these hormones were added to CCL3 because they were "known or 

anticipated to occur in public water systems" (74 Fed. Reg. 51855). However, contrary to this 

assertion, the data summarized in EPA’s Information Compendium shows that none of the seven 

hormones have ever been measured in finished drinking water, but were found at very low 

concentrations and at low frequency in source water.[FN2: Snyder, S.A., R.A. Trenholm, E.M. 

Snyder, G.M. Bruce, R.C. Pleus, and J.D.C. Hemming. 2008. Toxicological Relevance of EDCs and

Pharmaceuticals in Drinking Water. AWWA.]

Based on the data summarized in the Information Compendium, most of the measured ambient 

surface water concentrations of these seven hormones are substantially lower than the human health 

risk levels identified for the chemicals. Finally, because oxidative treatment (e.g., chlorination) 

rapidly eliminates that estrogenic activity of these chemicals, it is unlikely that any of them would

persist through conventional drinking water treatment.[FN3: Sedlak, DL and von Gunten, U. 2011. 

The chlorine dilemma. Science 331: 42-43. ]

A study published in 2010 evaluated potential human exposure to estrogenic compounds in drinking 

water including natural estrogens, prescribed endogenous estrogens, and prescribed synthetic 

estrogens (EE2).[FN4: Caldwell, D.J., Mastrocco, F., Nowak, E., Johnston, J., Yekel, H., Pfeiffer, D., 

Hoyt, M., DuPlessie, B., and Anderson, P. 2010, "An Assessment of Potential Exposure and Risk 

from Estrogens in Drinking Water." Environ. Health Perspectives. 118(3): 338-344.] This study, 

which assumed no removal of estrogenic compounds by drinking water treatment, used the 

Pharmaceutical Assessment and Transport Evaluation (PhATE) model to predict nationwide 

estimates of drinking water exposure to the target estrogenic compounds for adults and children. 

The predicted margins of safety (MOS) for an adult’s exposure to total prescribed estrogens in 
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drinking water vary from about 135 to > 17,000, depending on the acceptable daily intake (ADI) for 

a specific estrogen. MOS for exposure to total estrogens in drinking water are about 2 times lower 

than MOS for prescribed estrogens. Depending on the ADI that is used, MOS for young children 

range from 28 to 5,120 for total estrogens (including both prescribed and naturally occurring 

sources) in drinking water. This study concluded that total estrogens (natural and synthetic) in public 

drinking water supplies are not causing adverse effects in U.S. residents, including sensitive 

subpopulations. 

A second study, published in 2011, resulted in the same conclusion for synthetic estrogen used in 

oral contraceptives.[FN5: Op cit., Wise, A., O’Brien, K., and Woodruff, T., 2011.] This study 

concluded that the risks of EE2 in drinking water are negligible.

While there is considerable public concern regarding the presence of pharmaceutical compounds in 

public water supplies, there is a significant amount of data that supports the conclusions of EPA’s 

draft 2008 CCL3 list - that APIs in drinking water including the seven hormones on the proposed 

UCMR3 list are typically not present at concentrations that merit nationwide testing of all public 

drinking water supplies. We do not object to such testing; however, the particularly low detection 

limits called for will require exceptional technique; thus, demonstrating accuracy, reproducibility and 

inter-laboratory consistency will be extremely challenging but crucial.

Response: EPA has clarified the six applicable fact sheets in the Compendium by stating that the 

hormones are naturally produced within the human body, and are included in pharmaceutical 

products. National monitoring will allow EPA to assess the occurrence of these hormones in 

drinking water. Please see response to comment code 31000 Hormones. 

Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31668

Comment Code: 31000

Other EPA Comment Codes and Descriptions: 31050 Health Effects - Hormones 

Comment: May 2,2011

Water Docket U.S. Environmental Protection Agency Mail Code 282211T 1200 Pennsylvania 

Avenue, N.W. Washington, DC 20460

Re: Docket ID No. EPA-2009-0090 Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR 3) for Public Water Systems (76 Fed. Reg. 11713, March 3, 2011)

Ladies and Gentlemen:

Merck & Co., Inc. is pleased to submit these comments on the U.S. Environmental Protection 

Agency's (EPA) Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for 

Public Water Systems. EPA has published proposed monitoring requirements for 30 contaminants 

(76 Fed. Reg. 11713, March 3, 2011), most of which are on its Candidate Contaminant List 3 (CCL3) 

that was published in 2009. The Proposal makes available for public review and comment the 
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proposed monitoring for evaluation of potential drinking water contaminants that should be 

investigated further for possible addition to the primary drinking water regulations. There are seven 

hormones, six of which are naturally occurring, that are included on proposed List 1 for assessment. 

Merck has reviewed the Proposal and the basis for including these hormones in UCMR 2 and has 

prepared the following comments to EPA.

The justification for including several of the hormones selected for List 1 assessment monitoring 

does not sufficiently demonstrate concern for public health. 

As presented at the Stakeholder Meeting Regarding Revisions to the Unregulated Contaminant 

Monitoring Regulation, equilin, estrone, and estriol are all included in the monitoring exercise based 

on "estrogenic hormonal response in post-menopausal women" and structural similarity to estradiol. 

There are many substances, naturally occurring and synthetic, with structural similarity to estrogen 

that could trigger receptor responses with varying potency. We do not believe that these 

characteristics alone justify inclusion and suggest they should be removed from the monitoring 

proposal. 

Furthermore, looking at the CCL3 list posted to the Agency website, we do not see testosterone or 

4-androstene-3, 17-dione included and question how these substances were introduced into the 

UCMR3 list. In addition, the above-cited presentation uses structural similarities to testosterone as 

the basis for inclusion of 4-androstene-3, 17-dione which we regard as insufficient evidence of 

potential for public health concern and propose that it be removed from the UCMR3 list.

Response: The structural similarity among equilin, estrone, and estriol with estradiol was only one 

aspect that led to these compounds being included in the current Candidate Contaminant List (CCL 

3). The Agency considered the best available data and information on health effects and occurrence 

to evaluate thousands of unregulated contaminants. EPA used a multi-step process that resulted in 

the selection of 116 candidates for the final CCL 3. The final CCL 3 includes 104 chemicals or 

chemical groups and 12 microbiological contaminants. 

The androgens were selected because of their health impacts and the occurrence data currently 

available. Please see response to comment code 31000 Hormones. 

Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31669

Comment Code: 31000

Comment: The justification for including the seven hormones selected for List 1 assessment 

monitoring does not appropriately recognize the fact that all but one occur naturally and are 

excreted in urine.

EPA has included the following seven hormones on the proposed UCMR3 analyte list: 17-Bestradiol, 17-a-ethynylestradiol (EE2), estriol, estrone, testosterone, 4-androstene-3,17- dione and 

equilin (76 Fed. Reg. 11718). Six of these hormones occur naturally only EE2 is exclusively a 

synthetic hormone. EPA's "Possible Contaminants for Inclusion on UCMR3-Information 
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Compendium" (EPA 815-B-10-002)(Information Compendium) describes the "background" for 

each of these hormones and lists all seven as "used in pharmaceuticals." While this statement is 

accurate, it is incomplete and misleading. In fact, the principal source of the six naturally occurring 

hormones in the effluents of publicly owned treatment works (POTWs) and surface water used as 

drinking water supplies is human and animal excretion of these chemicals. [FN1: Wise, A., O'Brien, 

K., and Woodruff, T., "Are Oral Contraceptives a Significant Contributor to the Estrogenicity of 

Drinking Water?" Env. Sci. & Technol., 45, no. 1,2011, pp. 51-60.] It is misleading to the public and 

the drinking water industry to imply that the principal source of these six hormones is their use in 

pharmaceutical products. Merck requests that EPA clarify that all of hormones on the UCMR3 list 

with the exception of EE2 are naturally occurring and are used in pharmaceuticals.

The inclusion of the seven hormones on the proposed UCMR3 list is not justified by their frequency 

of occurrence in untreated source water and the risk associated with the concentrations that have 

been measured in such waters.

EPA's contaminant candidate list 3 (CCL3) methodology evaluated 287 active pharmaceutical 

ingredients (API) as candidate CCL3 contaminants (the universe). Approximately 10% of these APIs 

were included on the preliminary CCL. The Agency concluded that only one API, nitroglycerin, 

should be proposed for inclusion on the CCL3 (73 Fed. Reg. 9652). No hormones were identified 

for inclusion on the proposed CCL3. However, when the final rule was published, five of the 

hormones in the UCMR3 proposal (testosterone and 4-androstene-3,17-dione are not on current 

CCL3) were identified on the final CCL3 list, even though the Agency had previously concluded that 

they were not found at sufficient frequency and at concentrations that presented a human health risk 

through the drinking water pathway. The Agency states that these hormones were added to CCL3 

because they were "known or anticipated to occur in public water systems" (74 Fed. Reg. 51855). 

However, contrary to this assertion, the data summarized in EPA's Information Compendium 

shows that these hormones were not detected in finished drinking water [FN2: Snyder, S.A., R.A. 

Trenholm, E.M. Snyder, G.M. Bruce, R.C. Pleus, and J.D.C. Hemming. 2008. Toxicological 

Relevance of EDCs and Pharmaceuticals in Drinking Water. AWWA.] but were found at low 

concentrations and at low frequency in source water.

EPA's Information Compendium summarizes available data on the frequency of occurrence of each 

of the seven hormones proposed for monitoring. None of the seven hormones have ever been 

measured in finished drinking water based on EPA's data summaries in the Information 

Compendium.[FN3:Snyder, et al., 2008.] Furthermore, their frequency of occurrence in surface and 

ground water supplies is, in general, low.

Based on the data summarized in the Information Compendium, most of the measured ambient 

surface water concentrations of these seven hormones are substantially lower than the human health 

risk levels identified for the chemicals. Finally, because oxidative treatment (e.g., chlorination) 

rapidly eliminates that estrogenic activity of these chemicals,[FN4: Sedlak, DL and von Gunten, U. 

20 II. The chlorine dilemma. Science 331: 42-43] it is unlikely that any of them would persist 

through conventional drinking water treatment. 

Response: EPA has clarified the six applicable fact sheets in the Compendium by stating that the 

hormones are naturally produced within the human body, and are included in pharmaceutical 

products. National monitoring will allow the EPA to assess the occurrence of these hormones in 

drinking water. Please see response to comment code 31000 Hormones. 
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Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31671

Comment Code: 31000

Comment: The particularly low detection limits called for will require exceptional technique; thus, 

demonstrating accuracy, reproducibility and inter-laboratory consistency will be extremely 

challenging and crucially important. 

Response: EPA agrees that laboratories need to exercise due diligence in performing the analyses. 

Incorporation of field blanks and careful sample handling procedures will be required. Please see 

response to comment code 31000 Hormones. 

Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31673

Comment Code: 31000

Comment: EPA has included the several substances on the proposed UCMR3 analyte list based on 

EPA's "Possible Contaminants for Inclusion on UCMR3-Information Compendium" (EPA 815-BI0-002 Information Compendium). In the "background" information reported for several 

substances shows some references [FN7: Kolpin, et al. Environ. Sci. Technol. 2002, 36 (6),1202-

1211] that have over reported median values used to justify widespread exposure. While some of the 

references do provide a significant contribution toward the understanding of the occurrence of 

compounds, such as personal care products and pharmaceuticals, following their intended use, we 

would like to comment on two points that Merck believes are scientifically important and would be 

of value to EPA and the general public. In the Kolpin paper there were some unintended reporting 

bias issues that needs to be understood and avoided in the future. 

The issues are:

(i) Reporting a median concentration based only on those samples where analytes were actually 

detected and ignoring the samples that were non-detect; and

(ii) The inclusion of data with reported concentrations of target contaminants in field blanks (see 

above comments) 

Without clear adherence to scientific data management and reporting practices, results of reported 

median values will suggest concentrations of a substance in the environment that is significantly 

higher than actually detected.

Response: Reporting will be consistent with EPA procedures. For example, field blanks: positive 

results in field blanks indicate contamination introduced by the sampling procedure and the need for 
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collecting new samples. Please refer to UCMR 3 Laboratory Approval Requirements and 

Information Document for additional information. Please see response to comment code 31000 

Hormones. 

Commenter Name: Roger Sokol 

Commenter Organization: NY State Dept. of Health

Letter ID: 0065

Comment ID: 31678

Comment Code: 31000

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: Recommendation for dropping a contaminant from the UCMR3 list 

Since EPA is limited to monitoring (up to) thirty (30) compounds for the UCMR and the proposed 

regulation already includes 30 contaminants (28 chemicals: hormones, VOCs, SOCs, metals, 

perfluorinated chemical and an oxyhalide anion and 2 viruses [entero and noro], one contaminant 

will need to be dropped from the list, should chromium-6 be added. The BWSP suggests dropping 

one of the hormones from the proposed UCMR3 list due to the fact that the 7 proposed hormones 

originate from similar sources, and we feel that collecting data on 6 of the hormones will still be a 

significant accomplishment towards addressing the issue of endocrine disruption, especially since 

some of the hormones have similar chemical structures. Chemicals with similar structures are 

expected to have similar fate and transport. 

Thank you for your consideration of these comments. Please contact Dr. Lloyd Wilson 

(lrw03@health.state.ny.us) or Ms. Kim Evans (kem01@health.state.ny.us) of my staff if we can 

provide additional information or clarification of these comments, if needed. 

Sincerely,

Roger C. Sokol, Ph.D. Director Bureau of Water Supply Protection 

Electronic cc: V. Pisani T. Hunt L. Wilson K. Evans 

Response: Please see response to comment codes 31000 Hormones and 38100 Chromium-6.

Commenter Name: Neil Parke

Commenter Organization: Eli Lilly and Company

Letter ID: 0076

Comment ID: 31698

Comment Code: 31000

Comment: 7. EPA needs be sure that the reporting of the magnitude and frequency of measured 

concentrations of all substances adhere to scientific data management and reporting practices. Data 

reporting issues need to be clearly addressed to justify any future exposure and assessment reporting 

for further regulatory action on the substances listed on the OCMR rule and any CCL in the future. 
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EPA has included several substances on the proposed UCMR 3 analyte list based on EPA’s 

"Possible Contaminants for Inclusion on UCMR 3-Information Compendium" (EPA 815-B-10-002 

Information Compendium). In the "background" information reported for several substances shows 

some references [FN6: Kolpin, et al. Environ. Sci. Technol. 2002, 36 (6), 1202-1211] that have over 

reported median values used to justify widespread exposure. While some of the references do

provide a significant contribution toward the understanding of the occurrence of compounds, such 

as personal care products and pharmaceuticals, following their intended use, we would like to 

comment on two points that Lilly believes are scientifically important and would be of value to EPA 

and the general public. In the Kolpin paper there were some unintended reporting bias issues that 

need to be understood and avoided in the future. The issues are: 

(i) Reporting a median concentration for only those samples where analytes were detected; and

(ii) The inclusion of data with reported concentrations of target contaminants in field blanks (see 

above comments) 

Without clear adherence to scientific data management and reporting practices, results of reported 

median values will suggest concentrations of a substance in the environment that is significantly 

higher than actually detected.

Summary

Lilly supports the approach that EPA has developed to implement UCMR 3. We appreciate EPA’s 

consideration of these comments and particularly recommend that EPA emphasize the natural 

sources of most of the target hormones when it describes the sources of such chemicals in drinking 

water supplies. Lilly continues to be actively in industry efforts to develop new methodologies to 

evaluate the presence, fate and potential human health effects of APIs in surface and ground waters. 

We appreciate the opportunity to offer these comments. If you have any questions about Lilly’s 

comments, please contact me at (317) 276-7201.

Sincerely,

Neil Parke, M.A. Global HSE Consultant Eli Lilly and Company

Response: Reporting will be consistent with EPA procedures. For example, field blanks: positive 

results in field blanks indicate contamination introduced by the sampling procedure and the need for 

collecting new samples. Please refer to UCMR 3 Laboratory Approval Requirements and 

Information Document for additional information. Please see response to comment code 31000 

Hormones. 

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31795

Comment Code: 31000
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Comment: If Cr+VI is included in UCMR-3, DEP recommends that one of the hormones not on 

the CCL-3 list, be deleted, such as testosterone.

Response: EPA believes that monitoring for testosterone is justified. EPA has described its 

rationale for including this contaminant in the proposed rule on March 3, 2011 (76 FR 11713). A 

number of published articles show the occurrence of testosterone in surface waters and testosterone 

has been shown to be relatively resistant to oxidation. Please see response to comment codes 31000 

Hormones and 38100 Chromium-6.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31881

Comment Code: 31000

Comment: * Some of the hormones from the current UCMR3 list could be eliminated due to the 

fact that the seven proposed hormones originate from similar sources; thus, we feel that collecting 

data on a shorter list of the hormones will still be a significant accomplishment towards addressing 

the issue of endocrine disruption, especially since some of the hormones have similar chemical

structures. Chemicals with similar structures are expected to have similar fate and transport. 

Response: Please see response to comment codes 31000 Hormones and 38100 Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32052

Comment Code: 31000

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: The very low proposed MRLs for the hormones make it conceivable that even with 

precautions and instructions, there will be a possibility of positive values that could be due to 

extraneous factors outside of drinking water contamination. Given the sampling and handling 

challenges and newness of the method for hormones (EPA Method 539), AWWA continues to 

recommend that these compounds be included in a List 2, Screening Survey, sampling strategy. 

Using a Screening Survey is consistent with the UCMR framework and has been used in both 

UCMR 1 and 2. In UCMR2, all systems greater than 100,000 persons served (not including those 

systems that rely solely on purchased water) participated in the Screening Survey. This is a smaller 

sample but it also tends to sample systems that have the capacity and internal staffs necessary to 

assure appropriate quality control steps are taken in field sampling and oversight of the contract 

laboratory processing the samples. AWWA recommends that EPA: 

1. Monitor for hormones through a List 2, Screening Survey; 

2. Base the Screening Survey sample on retail population with the UCMR2 population threshold of 

100,000 population served;
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3. Prepare, in collaboration with the water system and laboratory community, appropriate guidance 

to assure that necessary quality assurance and control procedures are well understood; and 

4. Include field blanks in EPA Method 539 sampling procedures and clear guidance on what water 

systems and laboratories should do with associated samples if a field blank is positive, similar to the 

guidance that is included in EPA Method 537.

Response: Please see response to comment codes 31000 Hormones and 31010 EPA Method 539 - 

Hormones. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32066

Comment Code: 31000

Comment: Table 1. Relevant Rationale for Removing Specific Contaminants from UCMR3 [See

PDF Docket ID: EPA-HQ-OW-2009-0090-0080.1] Hormones / EPA 539 / Testosterone, 4-

androstene-3,17-dione / Not on CCL3 - CCL3 is the appropriate process for ranking contaminants 

for data collection. 

Response: EPA believes that monitoring for testosterone, 4-androstene-3,17-dione, chloromethane, 

1,3-butadiene, chlorodifluoromethane, strontium, PFNA, PFHxS, PFHpA, and PFBS are justified. 

Please see response to comment codes 31000 Hormones and 38100 Chromium-6.
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Comment Code: 31010 EPA Method 539 - Hormones

Summary Response to Comments on EPA Method 539 - Hormones: Regarding comments on 

the need for field blanks for samples analyzed by EPA Method 539, EPA will change the language in 

the UCMR 3 Laboratory Approval Requirements and Information Document to address the 

collection and analysis of a field blank. The document concerning criteria for laboratory blank 

contamination is a 1993 document for the analysis of waste water. Due to the extremely large data 

acceptance criteria for many waste water methods, the 1993 waste water document suggests that 

analytes only be reported when their concentration exceeded 10 times the level seen in the 

laboratory reagent blank. However, with the far tighter (+/- 30%) criteria of modern drinking water 

methods, such as Method 539, the requirement that analytes must be seen at 3 times the laboratory 

reagent blank is appropriate for these methods.

Regarding comments on the threshold for rejecting results when analytes are detected in blanks, the 

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

table. 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 of the MRL. EPA will require 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.

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

EPA has also provided in the rule that it will evaluate results of the first six months of monitoring. If 

the data indicate that excessive resampling is occurring, EPA will establish alternative MRLs and will 

notify all affected PWSs and laboratories.

Regarding comments on the need for field blanks, field blanks will be required for samples collected 

under UCMR 3. The UCMR 3 laboratory procedures manual will specify that if any of the hormones 

are found in a field sample, then the field blank must be analyzed. If the field blank level is at a 

concentration greater than 1/3 the MRL, then samples collected with that field blank are invalid and 

new samples must be collected. EPA Method 539 is an LC/MS/MS method. This technique was 

used in Screening Surveys conducted during UCMR 2. In addition, for the final rule, EPA has 
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moved the hormone monitoring requirement from Assessment Monitoring (List 1) to Screening 

Survey (List 2). This change will substantially reduce the number of PWSs that are required to 

monitor for hormones and mitigate any concerns regarding laboratory capacity.

Regarding comments on the choice of surrogates for EPA Method 539, in many analytical methods, 

multiple surrogates are selected to test for different potential sources of inaccuracy. In the case of 

Method 539, this is not the case; either of the surrogates is equally protective. However, based on 

the specific chromatography selected by the analyst, there may be more interference with one of the 

surrogates versus the other; therefore, laboratories are permitted to select the surrogate that is least 

impacted by these interferences.

Individual Comments

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31598

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 31000 Hormones

Comment: - AMWA has additional concerns about EPA Method 539. Specifically, with such a low 

minimum reporting level (MRL) for this method, there is a potential for samples to be contaminated 

due to external factors or improper QA/QC techniques. 

* AMWA recommends that the analytes to be measured for EPA Method 539 be included under 

List 2, Screening Survey. As noted in our detailed comments about the analytical methods, below, 

there are many potential issues associated with the sampling protocols and analytical method 

associated with this new method and therefore, AMWA believes it is more appropriate to include 

the five hormones on CCL-3 (17alpha-estradiol, 17-beta estradiol, estriol, estrone and ethinyl 

estradiol) as List 2 analytes. AMWA recommends that EPA select the same utilities to sample for 

List 2 analytes as in previous UCMR rulemakings (i.e., systems serving more than 100,000 persons).

Response: Please see response to comment code 31000 Hormones. 

Commenter Name: Dennis O'Sullivan

Commenter Organization: DoD Safe Drinking Water Act Services Steering Committee

Letter ID: 0048

Comment ID: 31613

Comment Code: 31010

Comment: [1] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 6 Para#/ 

Line# (Methods documents): METHOD 539: 4.4 Comment Classification C/M/S/A: S 

Comment: Recommendations need to be requirements. 
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Rationale: This should be a requirement (must), not a recommendation (should). This lends itself to 

the extraction of samples using media that has not been tested and may result in the need to 

recollect samples due to a laboratory error that could have been avoided. 

[2] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 10; 11 Para#/ Line# 

(Methods documents): METHOD 539: 7.2.1.2; 7.2.2.2 Comment Classification C/M/S/A: S 

Comment: Expiration requirements need to be clearly defined. 

Rationale: It is recommended that the method provide a definitive expiration for these standards, 

especially considering there is no verification for these standards (second source or second standard) 

used in the analysis. 

[3] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 12 Para#/ Line# 

(Methods documents): METHOD 539: 7.2.4 Comment Classification C/M/S/A: S 

Comment: Options for media testing need to be requirements. 

Rationale: If the filtration of CAL standards is due to potential differences in retention times of 

analytes in filtered versus non-filtered samples, or for any other technical reason, it is recommended 

that this be made a requirement, not a recommendation. If it is required, or even recommended, 

wouldn't all standards, including RW, QCSs, and CCCs need to be filtered as well? 

[4] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 12; 13 Para#/ Line# 

(Methods documents): METHOD 539: 7.2.4; 8.3; 8.4 Comment Classification C/M/S/A: S 

Comment: Temperature and hold time requirements vary without explanation. 

Rationale: Why are the shipping and laboratory storage temperature requirements different? Extracts 

are stored at 0° C for no more than 28 days, while section 7.2.4 states the calibration standards must 

be stored at 6° C or less and have proven to be stable for up to two weeks. Both the extracts and 

calibration standards are in 50% methanol. Samples are to be shipped at less than or equal to 10°C, 

yet the laboratory must store the samples once received at less than or equal to 6°C. 

[5] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 12; 21; 22 Para#/ 

Line# (Methods documents): METHOD 539: 7.2.4; 10.2.2; 10.2.3 Comment Classification 

C/M/S/A: S 

Comment: Information on how the surrogate concentrations are calculated in samples and QC is 

not provided. 

Rationale: The method provides no information on how the concentration of surrogate is calculated 

from the calibration curve. The options provided in the method for calibration do not apply to the 

surrogate since all CAL standards contain the same concentration of surrogates. It appears that the 

method allows for the use of single point calibration, but it does not specify which standard should 

be used for this calibration. It is recommended that the method require the surrogate be treated in 

the same manner as the target analytes in regards to the calibration levels and acceptance criteria.
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[6] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 16 Para#/ Line# 

(Methods documents): METHOD 539: 9.3.1 Comment Classification C/M/S/A: A 

Comment: Non-detects in samples are not considered separately.

Rationale: This section states that regardless of whether detected or not in a sample, the results will 

be invalidated if the LRB fails to meet acceptance criteria. It is recommended that an exception be 

made for samples in which the analyte was not detected.

[7] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 16; 19; 22 Para#/ 

Line# (Methods documents): METHOD 539: 9.3.3; 9.3.7.2; 10.3.4 Comment Classification 

C/M/S/A: S 

Comment: Sliding scale of acceptance criteria over the quantitation range introduces additional 

uncertainty to the analysis.

Rationale: Since the low-level LFB concentration is within the quantitation range (1 - 2 times MRL), 

it is not justified to have varying acceptance criteria within the quantitation range. It cannot be 

determined at what point the uncertainty changes from 50 to 30%. It is recommended that the same 

acceptance criteria be used for each LF, regardless of the concentration. This same comment applies 

to the evaluation of RPDs of the field duplicates and LFSM and LFSMDs (Section 9.3.7.2) and CCC 

recoveries (Section 10.3.4).

[8] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 17; 24 Para#/ Line# 

(Methods documents): METHOD 539: 9.3.4; 11.3 Comment Classification C/M/S/A: S 

Comment: Internal standard addition process is prohibiting and included as part of the extraction 

process.

Rationale: It is recommended that the internal standard be added just prior to analysis. The internal 

standard should be added post filtering. Filtering is part of the extraction process, therefore the 

internal standard should not be allowed to be affected by this step. By spiking only a portion of the 

final extract, the laboratory will have the ability to correct for any internal standard spiking errors 

without reextraction or collection of more sample. 

[9] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 17 Para#/ Line# 

(Methods documents): METHOD 539: 9.3.5.3 Comment Classification C/M/S/A: S

Comment: Unclear which standard is being referenced.

Rationale: Does this mean the last CCC standard or last CAL standard analyzed in the calibration 

curve? It is recommended the last CCC standard analyzed be used since it would the most recent 

standard analyzed.

[10] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 18 Para#/ Line# 

(Methods documents): METHOD 539: 9.3.6.3 Comment Classification C/M/S/A: S
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Comment: Concentrations less than the MRL are used to correct the LFSM and LFSMD are 

qualitative and not reported in the native samples. 

Rationale: Only concentrations greater than the MRL are reported in native samples, yet this section 

states the LFSM and LFSMD are to be corrected for using native sample values that are below the 

MRL. It is recommended that LFSM and LFSMD values only be adjusted using values reported in 

the native samples (between the MRL and highest calibration standard). 

[11] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 20 Para#/ Line# 

(Methods documents): METHOD 539: 10.1.1 Comment Classification C/M/S/A: S 

Comment: Mass calibration may not include entire range of masses used for quantification. 

Rationale: It is recommended that a requirement for the range of masses used for the calibration 

bracket that of the precursor and product ions being tested. 

[12] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 21 Para#/ Line# 

(Methods documents): METHOD 539: 10.2.2 Comment Classification C/M/S/A: S 

Comment: Forcing through the origin is not recommended, but not prohibited. 

Rationale: It is recommended that forcing through the origin be prohibited. 

[13] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 22 Para#/ Line# 

(Methods documents): METHOD 539: 10.2.3 Comment Classification C/M/S/A: S 

Comment: The acceptance criteria calibration curve is not provided.

Rationale: The criteria (e.g., %RSD, correlation coefficient) used for evaluating the calibration curve 

that is generated by the calibration standards is not defined by the method. It is recommended 

criteria for the curve be included along with the requirements for each calibration standard. 

[14] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 539: 25 Para#/ Line# 

(Methods documents): METHOD 539: 12 Comment Classification C/M/S/A: S 

Comment: Missing evaluation criteria

Rationale: There is no discussion of evaluation of relative retention times and Why doesn't the 

method require evaluation of the isotope area count ratios for standards, samples, and batch QC and 

acceptance criteria for them. Does this mean they are not to be evaluated?

Response: [1] EPA is not requiring that laboratories test each lot of materials before use since the 

laboratory reagent blank requirements in Section 9.3.1 will assure that no data are reported if a 

laboratory did use contaminated extraction materials. In Section 4.4, EPA has recommended that all 

solid phase extraction materials be tested for interferences prior to their use. This recommendation 

was made to help laboratories eliminate lost time and effort by extracting a set of samples using new 

extraction materials without testing them and subsequently determining that the materials are 

contaminated. 
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[2] Section 9.3.8 requires that each time a new primary dilution standard is prepared, that its accuracy 

be verified by analyzing a second source standard.

[3] Section 11.4 requires that if the laboratory does filter extracts (which is recommended because 

sample extracts may contain particulates that will shorten the life of the analytical column - since 

calibration standards are made in reagent water, no particulates are present in calibration standards) 

they must first verify that each lot of the filters used do not adversely impact analytical accuracy by 

requiring the analysis of filtered and unfiltered calibration standards. 

[4] The extract holding time and temperature are required maximums. Extracts must be held at a 

maximum of 0 deg. C, for a maximum of 28 days. These requirements are based upon analysis 

performed during analytical methods development. The storage temperature and duration for 

calibration standards is only a recommendation, with an example (two weeks at or less than 6 deg. 

C). The stability of the calibration standards is assured through the quality control requirements of 

the method, whereas, the stability of the extracts can only be assured by the laboratories adherence 

to the extract holding requirements. 

While it would be optimal to store samples at 6 deg. C from collection to analysis, it is impractical. 

Maintaining 6 deg. C during transport from the sampling location to the laboratory is extremely 

difficult. Most commercially available frozen gel packs will not maintain 6 deg. C. However, they can 

maintain the required 10 deg. C. Therefore, when sample holding times are developed during 

methods development, the samples are maintained at 10 deg. C for 48 hours and then the 

temperature is reduced to 6 deg. C for the remainder of the holding time testing to more accurately 

represent actual shipping and storage conditions. 

[5] As detailed in Section 9.3.5, the surrogates are added to all field samples, QC samples and 

calibration standards at the same concentration. This section also provides the equation necessary to 

determine surrogate recovery. Since the surrogates are added at the same concentration to all 

samples and standards, determination of the absolute concentration of the surrogates are not 

necessary. The only important data point is the recovery.

[6] While the commenter raises an interesting point, EPA believes that the laboratory reagent blank 

(LRB) represents a fundamental quality control element that must be met. Since the only source of 

contamination of an LRB is within the laboratory itself or the reagents that it uses, contamination of 

an LRB indicates the potential for contamination of a field sample. Therefore, the source of the 

contamination must be corrected before analyzing further samples.

[7] EPA disagrees. EPA has defined the Minimum Reporting Limit (MRL) for all UCMR 3 analytes 

and methods as the concentration that can be monitored within of 50 - 150% of the true value. The 

precision and accuracy of chemical analysis is a function of the concentration being measured, 

therefore, it is valid to specify data quality objectives that take this fact into account and change the 

data quality requirements to a level consistent with the performance of each method for 

concentrations exceeding the MRL. 

[8] Accurate addition of the Internal standard (IS) is dependent on accurately knowing the volume 

of both the amount of IS solution added to the extract and the volume of the extract itself. Section 

11.3 represents the only step in the method where the volume of the final extract is accurately 

known, and therefore, is the only appropriate point for the addition of the IS. 
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[9] A CCC is defined at the beginning of the method as "A calibration standard that is analyzed 

periodically to verify the accuracy of the existing calibration." Therefore, the last CCC or CAL 

standard are both acceptable.

[10] The Minimum Reporting Limit (MRL) is simply the lowest concentration that can be reported 

in a field sample. The quality control aspects, both qualitative and quantitative, are based upon the 

MRL. Calibration standards are run down to the MRL, reagent blanks are evaluated relative to the 

MRL. However, statistical evaluations of data quality, such as the LFSM and LFSMD, would be 

biased if values below the MRL were not incorporated. 

[11] The mass range of calibration standards and the flexibility of the software used by the 

instruments for calibration is highly limited. There are sufficient controls built into the Initial 

Demonstration of Capabilities required in this method that adequately assure the level of mass 

accuracy needed.

[12] EPA believes that the current statement in the method that forcing through zero is not 

recommended is correct. While we generally do not recommend forcing zero, in those cases where 

persistent low concentrations (below 1/3 the MRL) of the analytes are present in the reagent water, 

forcing through zero is the correct procedure for correcting the calibration. Therefore, we do not 

prohibit it.

[13] Criteria such as %RSDs or correlation coefficients are poor indications of the quality of the 

calibration curve. In both cases, these measures minimize what may be significant errors at low 

concentrations. Methods used for the analysis of drinking water, where accurate low concentration 

calibration is essential, use the procedure detailed in section 10.2.3 which requires each calibration 

standard to be compared back to the calibration curve and must be within 30% of their true value. 

This is a far better method of assuring the quality of the calibration curve. 

[14] Since this is a tandem mass spectrometry method, additional qualitative evaluations, such as 

comparing isotope ratios, does not provide useful additional qualitative certainty. 

Commenter Name: Daniel J. Caldwell

Commenter Organization: Johnson&Johnson 

Letter ID: 0057

Comment ID: 31641

Comment Code: 31010

Comment: The analytical method and quality assurance/quality control requirements proposed for 

the analysis of hormones in drinking water are necessary.

The proposed Method 539 (LC/MS/MS)(EPA 815- B-10-001, November 2010) is appropriate for 

identifying and quantitating these analytes in finished drinking water. The quality assurance/quality 

control (QA/QC) requirements of the method are critical and when followed rigorously by the 

participating laboratories, should assure that reliable quantitative data on the presence of hormones 

in finished drinking water is generated by UCMR3. The required routine analysis of replicates and

matrix spikes is essential to the quality of the resulting data. Anything less than the current QA/QC 

requirements in Method 539 would lessen the credibility and reliability of the measurements.
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31010 EPA Method 539 - Hormones Page 115 of 401

EPA should consider improving Method 539 by providing more specific requirements regarding the 

collection of field blanks, providing more stringent criteria on how to accept or reject data generated 

from field blank data analysis, and improving the method section on "surrogate analytes." 

Section 4.7 of Method 539 states: "Depending on the sampling site, it may be appropriate to include 

a Field Blank with the sampling bottles... The Field Blank is shipped back to the lab along with the 

samples and analyzed along with the samples to ensure that no human hormones were introduced 

into the samples during the collection and handling process. In general, if the Field Blank shows 

analytes present at a level >1/3 the MRL, the samples should be flagged accordingly and new 

samples collected if possible."

We believe that EPA needs to modify language to specify minimum criteria regarding sampling site 

and about when it is "appropriate" to collect a field blank. Adequate field blank sampling is very 

important and if not sufficiently conducted could result in over reporting concentrations of 

contaminants. Field blank data reporting issues in some of the studies referenced in EPA’s 

Information Compendium have been observed. It is standard good laboratory practice to reject data 

when the target analyte is detected in the field blank. 

We urge the Agency to reject data when the reported concentration of the target analyte is less than 

10 times greater than that in the field blank as stated in U.S. Environmental Protection Agency. 

Guidance on evaluation, resolution, and documentation of analytical problems associated with

compliance monitoring; EPA821-B-93-001; U.S. Government Printing Office: Washington, DC, 

June 1993.

Section 7.2.2 regarding "Surrogate Analytes" states: "Two isotopically labeled surrogates were 

evaluated during method development and are listed in the following table. Only one surrogate, 

however, is required to be evaluated with each extraction batch. The analyst is permitted to select 

the surrogate that performs best under the LC-MS/MS conditions employed for the analysis. Other

alternate surrogate standards may be used provided they meet the QC requirements described in 

Section 9.3.5."

We question the use language that instructs a laboratory to select the surrogate that performs "best" 

under the LC-MS/MS conditions employed for the analysis. Providing a surrogate that represents 

the "best" performance of the LC-MS/MS conditions may lessen quality data for some substances.

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 

Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31672

Comment Code: 31010

Comment: The analytical method and quality assurance/quality control requirements proposed for 

the analysis of hormones in drinking water are appropriate. 
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31010 EPA Method 539 - Hormones Page 116 of 401

The proposed Method 539 (LC/MS/MS)(EPA 815-B-l 0-001, November 2010) is appropriate for 

identifying and quantitating these analytes in finished drinking water. The quality assurance/quality 

control (QA/QC) requirements of the method are critical and when followed rigorously by the 

participating laboratories, should assure that reliable quantitative data on the presence of hormones 

in finished drinking water is generated by UCMR3. The required routine analysis of replicates and 

matrix spikes is essential to the quality of the resulting data. Anything less than the current QA/QC 

requirements in Method 539 would lessen the credibility and reliability of the measurements.

EPA should consider improving Method 539 by providing more specific requirements regarding the 

collection of field blanks, providing more stringent criteria on how to accept or reject data generated 

from field blank data analysis, and improving the method section on "surrogate analytes." Section 

4.7 of Method 539 states: "Depending on the sampling site, it may be appropriate to include a Field 

Blank with the sampling bottles. At the lab, fill a sample bottle with reagent water and preservatives, 

seal, and ship it to the sampling site along with the other sample bottles. Also, include an empty 

sealed bottle. At the sampling site, open the bottle containing the preserved reagent water and pour 

it into the empty bottle (thus exposing it to the sampling environment). Seal and label as "Field 

Blank". The Field Blank is shipped back to the lab along with the samples and analyzed along with 

the samples to ensure that no human hormones were introduced into the samples during the 

collection and handling process. In general, if the Field Blank shows analytes present at a level> 1/3

the MRL, the samples should be flagged accordingly and new samples collected if possible." 

Merck believes that EPA needs to modify language to specify minimum criteria regarding sampling 

site and about when it is "appropriate" to collect a field blank. Adequate field blank sampling is very 

important and if not sufficiently conducted could result in over reporting concentrations of 

contaminants. Field blank data reporting issues in some of the studies referenced in EPA's "Possible 

Contaminants for Inclusion on UCMR3-Information Compendium" (EPA 815-B-I0-002) have been 

observed. It is standard good laboratory practice to reject data when the target analyte is detected in 

the field blank. 

Merck also supports rejecting data when the reported concentration of the target analyte is less than 

10 times greater than that in the field blank as stated in U.S. Environmental Protection Agency. 

Guidance on evaluation, resolution, and documentation of analytical problems associated with 

compliance monitoring; EPA821-B-93-001; U.S. Government Printing Office: Washington, DC, 

June 1993.

Section 7.2.2 regarding "Surrogate Analytes" states: "Two isotopically labeled surrogates were 

evaluated during method development and are listed in the following table. Only one surrogate, 

however, is required to be evaluated with each extraction batch. The analyst is permitted to select 

the surrogate that performs best under the LC-MS/MS conditions employed for the analysis. Other 

alternate surrogate standards may be used provided they meet the QC requirements described in 

Section 9.3.5."

We question the use language that instructs a laboratory to select the surrogate that performs "best" 

under the LC-MS/MS conditions employed for the analysis. Providing a surrogate that represents 

the "best" performance of the LC-MS/MS conditions may lesser quality data for the some 

substances.

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 
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January 2012

31010 EPA Method 539 - Hormones Page 117 of 401

Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31674

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 41000 Laboratory Approval Process/Laboratory 

Capacity

Comment: The laboratory approval process proposed for the UCMR3 is rigorous and is necessary 

to assure that data generated by the study suitable for assessing the presence of hormones in 

drinking water. 

The laboratory approval process for participants in UCMR3 (76 Fed. Reg. 11720) is suitably rigorous 

to assure that only laboratories that can achieve the QA/QC requirements of Method 539 are 

accepted. The inclusion of proficiency testing (PT) for qualification is also important. 

EPA should include analysis of proficiency test samples to complement laboratory audits during the 

2013-2015 monitoring period. 

EPA plans on conducting laboratory audits throughout the ongoing testing program (76 Fed. Reg. 

11721). Satisfactory audit results will be required in order for a laboratory to maintain approval for 

participation. However, the analysis of PT samples will only occur before the monitoring program 

begins. Merck recommends that participating laboratories be required to analyze at least one PT 

sample during the monitoring program. The results of this analysis should not necessarily be used to 

disqualify a laboratory as long as they have had a satisfactory audit. However, the results of this 

ongoing use of PT samples will serve as an additional check on the reliability of the monitoring data. 

Method 539 does not have any requirement that a laboratory analyze samples containing known 

amounts of the analytes that are prepared by an outside source and are therefore unknown to the 

analyst (PT samples). Requirements to test such samples are routine for laboratories in all of EPA's 

Office of Water programs and should be included in UCMR3. 

Summary

Merck supports the approach that EPA has developed to implement UCMR3. We appreciate EPA's 

consideration of these comments and particularly recommend that EPA emphasize the natural 

sources of most of the target hormones when it describes the sources of such chemicals in drinking 

water supplies. Merck works with other stakeholders to develop new methodologies to evaluate the 

presence, fate and potential human health effects of APIs in surface and ground waters and will 

continue to share this information with EPA.

We appreciate the opportunity to offer these comments. If you have any questions about these 

comments, please contact Mary Buzby at 908-423-7837.

Sincerely,

Barbara Schulze Director, Global Environmental Programs 
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31010 EPA Method 539 - Hormones Page 118 of 401

Response: Please see the response to comment code 41000 Laboratory Approval 

Process/Laboratory Capacity.

Commenter Name: Neil Parke

Commenter Organization: Eli Lilly and Company

Letter ID: 0076

Comment ID: 31696

Comment Code: 31010

Comment: 4. The analytical method and quality assurance/quality control requirements proposed 

for the analysis of hormones in drinking water appear appropriate. The particularly low detection 

limits called for will require exceptional technique; thus, demonstrating accuracy, reproducibility and 

inter-laboratory consistency will be extremely challenging but crucial. EPA should consider 

improving some sections of Method 539. 

The proposed Method 539 (LC/MS/MS)(EPA 815-B-10-001, November 2010) is appropriate for 

identifying and quantitating these analytes in finished drinking water. The quality assurance/quality 

control (QA/QC) requirements of the method are critical and when followed rigorously by the 

participating laboratories, should assure that reliable quantitative data on the presence of hormones 

in finished drinking water is generated by UCMR 3. The required routine analysis of replicates and 

matrix spikes is essential to the quality of the resulting data. Anything less than the current QA/QC 

requirements in Method 539 would lessen the credibility and reliability of the measurements.

EPA should consider improving Method 539 by providing more specific requirements regarding the 

collection of field blanks, providing more stringent criteria on how to accept or reject data generated 

from field blank data analysis, and improving the method section on "surrogate analytes." 

Section 4.7 of Method 539 states: "Depending on the sampling site, it may be appropriate to include 

a Field Blank with the sampling bottles. At the lab, fill a sample bottle with reagent water and 

preservatives, seal, and ship it to the sampling site along with the other sample bottles. Also, include 

an empty sealed bottle. At the sampling site, open the bottle containing the preserved reagent water 

and pour it into the empty bottle (thus exposing it to the sampling environment). Seal and label as 

"Field Blank". The Field Blank is shipped back to the lab along with the samples and analyzed along 

with the samples to ensure that no human hormones were introduced into the samples during the 

collection and handling process. In general, if the Field Blank shows analytes present at a level >1/3 

the MRL, the samples should be flagged accordingly and new samples collected if possible." 

Lilly believes that EPA needs to modify language to specify minimum criteria regarding sampling 

site and about when it is "appropriate" to collect a field blank. Adequate field blank sampling is very 

important and if not sufficiently conducted could result in over reporting concentrations of 

contaminants. Field blank data reporting issues in some of the studies referenced in EPA’s "Possible 

Contaminants for Inclusion on UCMR 3- Information Compendium" (EPA 815-B-10-002) have 

been observed. It is standard good laboratory practice to reject data when the target analyte is 

detected in the field blank. We would also support rejecting data when the reported concentration of 

the target analyte is less than 10 times greater than that in the field blank as stated in U.S.

Environmental Protection Agency. Guidance on evaluation, resolution, and documentation of 
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January 2012

31010 EPA Method 539 - Hormones Page 119 of 401

analytical problems associated with compliance monitoring; EPA821- B-93-001; U.S. Government 

Printing Office: Washington, DC, June 1993.

Section 7.2.2 regarding "Surrogate Analytes" states: "Two isotopically labeled surrogates were 

evaluated during method development and are listed in the following table. Only one surrogate, 

however, is required to be evaluated with each extraction batch. The analyst is permitted to select 

the surrogate that performs best under the LC-MS/MS conditions employed for the analysis. Other 

alternate surrogate standards may be used provided they meet the QC requirements described in 

Section 9.3.5.' We question the use language that instructs a laboratory to select the surrogate that 

performs "best" under the LC-MS/MS conditions employed for the analysis. Providing a surrogate 

that represents the "best" performance of the LC-MS/MS conditions may lesser quality data for the 

some substances.

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 

Commenter Name: Neil Parke

Commenter Organization: Eli Lilly and Company

Letter ID: 0076

Comment ID: 31697

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 41000 Laboratory Approval Process/Laboratory 

Capacity

Comment: 5. The laboratory approval process proposed for the UCMR 3 is rigorous and is 

necessary to assure that data generated by the study suitable for assessing the presence of hormones 

in drinking water. 

The laboratory approval process for participants in UCMR 3 (76 Fed. Reg. 11720) is suitably 

rigorous to assure that only laboratories that can achieve the QA/QC requirements of Method 539 

are accepted. The inclusion of proficiency testing (PT) for qualification is also important. 

6. EPA should include analysis of proficiency test samples to complement laboratory audits during 

the 2013-2015 monitoring period. 

EPA plans on conducting laboratory audits throughout the ongoing testing program (76 Fed. Reg. 

11721). Satisfactory audit results will be required in order for a laboratory to maintain approval for 

participation. However, the analysis of PT samples will only occur before the monitoring program 

begins. Lilly recommends that participating laboratories be required to analyze at least one PT

sample during the monitoring program. The results of this analysis should not necessarily be used to 

disqualify a laboratory if they have a satisfactory audit. However, the results of this ongoing use of 

PT samples will serve as an additional check on the reliability of the monitoring data. Method 539 

does not have any requirement that a laboratory analyze samples containing known amounts of the 

analytes that are prepared by an outside source and are therefore unknown to the analyst (PT 

samples). Requirements to test such samples are routine for laboratories in all of EPA’s Office of 

Water programs and should be included in UCMR 3.
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January 2012

31010 EPA Method 539 - Hormones Page 120 of 401

Response: Please see the response to comment code 41000 Laboratory Approval 

Process/Laboratory Capacity.

Commenter Name: Karen A. Randazzo 

Commenter Organization: Suffolk County Water Authority (SCWA) 

Letter ID: 0081

Comment ID: 31702

Comment Code: 31010

Comment: Also ethinyl estradiol and estrone had lower MRLs than listed in EPA Method 539. 

These lower MRLs may be very difficult for laboratories to achieve on a routine basis. 

The SCWA appreciates your consideration of these comments and looks forward to seeing the 

continued development of this important regulation. 

Sincerely,

Karen A. Randazzo Director of Water Quality and Lab Services SCWA Laboratory

Response: MRLs are based upon a multi-laboratory compilation of LCMRLs. LCMRLs are 

reported in EPA analytical methods. 

MRLs are not listed in EPA analytical methods because they are designed to broadly reflect varying 

national laboratory capabilities. The laboratory-specific value is the LCMRL and in more recentlydeveloped analytical methods such as EPA Method 539, EPA has included the EPA laboratoryspecific LCMRL for each method analyte. MRLs are determined by EPA for UCMR by pooling 

LCMRL study data from a group of laboratories, including EPA's method development laboratory. 

It is possible for the EPA LCMRL to be higher than the multi-laboratoy-determined MRL. The 

individual LCMRLs for ethynylestradiol were 0.14 ng/L, 0.18 ng/L, and 1.3 ng/L. The individual 

LCMRLs for estrone were 0.18 ng/L, 0.13 ng/L, and 2.9 ng/L. Since the EPA LCMRLs were 

determined using a less sensitive instrument than what is used in most commercial laboratories, it is 

not surprising that our LCMRLs were the highest.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31743

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 40000 Minimum Reporting Level 

Determination/LCMRLs

Comment: 3. We are concerned that with the low MRLs proposed for method 539, some non 

CCL3 analytes (e.g. testosterone) are low enough (0.0001 ug/L) to anticipate a potential for 

inadvertent field contamination or lab contamination. At present there is no provision in either 

method 539 or UCMR3 for a field blank on this method (and subsequent guidance on how to use 

the field blank to qualify/disqualify actual sample results). With the extremely low MRL and the
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31010 EPA Method 539 - Hormones Page 121 of 401

requirement that lab blanks be <1/3 of the MRL it is possible that labs will upon occasion have 

difficulty meeting this requirement, or there will be results that may be questionable as a result of 

field contamination, resulting in potential needs for resamples by utilities. The repercussion may be 

that prices for method 539 may be elevated (to account for the need for re-extractions) compared to 

where they would be with a more realistic MRL. Additionally, at these low MRLs, the desirability for 

a field blank would also increase costs (even more directly) for utilities.

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31777

Comment Code: 31010

Comment: Finally, if hormones are measured, AMWA has additional concerns about EPA Method 

539. Specifically, with such a low Minimum Reporting Level (MRL) for this method there is a 

potential for samples to be contaminated due to external factors or improper QA/QC techniques. 

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31791

Comment Code: 31010

Comment: Within the list of constituents, DEP has concerns about whether the Tier 1- Assessment 

Monitoring List is the appropriate place for one of the constituent classes. Our chief concern is with 

the inclusion of hormones at the proposed minimum reporting levels ("MRLs") which can be as low 

as the part-per- quadrillion level for reporting purposes. DEP will most likely have to use a contract 

laboratory to test for hormones using the proposed Method 539. However, there are many potential 

issues associated with the sampling protocols and analytical methods associated with this method 

and the proposed MRLs. If EPA is going to use these data for assessment monitoring and for 

inclusion in consumer confidence reports, it is critical that the QAJQC requirements for both 

laboratory analyses and for sampling be specified in the regulation or guidance. DEP has recently 

completed limited testing of our source waters for emerging contaminants, including hormones, 

using similar methods and through a contract laboratory. Due to concerns about potential crosscontamination of samples, say by transference of minute levels of hormones from skin oils, 

dandruff, etc. DEP's sample collection method required the collection of a substantive number of 

QC samples including duplicates of every sample, field and trip blanks, and samples for matrix 

spikes and matrix spike duplicates. DEP also used "clean hands" techniques during sample 

collection. These efforts paid off with very little cross-contamination or blank contamination. Unless 

EPA provides for rigorous QA/QC requirements that all water utilities can achieve, DEP 

recommends that EPA consider moving the hormone panel from Tier 1 to Tier 2-as a screening 

level assessment. DEP also recommends that EPA work "with water system and laboratory 
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31010 EPA Method 539 - Hormones Page 122 of 401

personnel in developing appropriate guidance to assure that necessary quality assurance and quality 

control procedures, for both field and laboratory, are well understood, and are appropriate to the 

proposed method and method reporting limits, and that QC samples are collected in the field by 

each utility and for each round of sampling and for each matrix sampled. 

Response: EPA agrees that sampling and handling guidance is needed for the hormones, and has 

added these types of instructions into the UCMR 3 Laboratory Approval Requirements and 

Information Document. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32052

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 31000 Hormones

Comment: The very low proposed MRLs for the hormones make it conceivable that even with 

precautions and instructions, there will be a possibility of positive values that could be due to 

extraneous factors outside of drinking water contamination. Given the sampling and handling 

challenges and newness of the method for hormones (EPA Method 539), AWWA continues to 

recommend that these compounds be included in a List 2, Screening Survey, sampling strategy. 

Using a Screening Survey is consistent with the UCMR framework and has been used in both 

UCMR 1 and 2. In UCMR2, all systems greater than 100,000 persons served (not including those 

systems that rely solely on purchased water) participated in the Screening Survey. This is a smaller 

sample but it also tends to sample systems that have the capacity and internal staffs necessary to 

assure appropriate quality control steps are taken in field sampling and oversight of the contract 

laboratory processing the samples. AWWA recommends that EPA:

1. Monitor for hormones through a List 2, Screening Survey; 

2. Base the Screening Survey sample on retail population with the UCMR2 population threshold of 

100,000 population served;

3. Prepare, in collaboration with the water system and laboratory community, appropriate guidance 

to assure that necessary quality assurance and control procedures are well understood; and 

4. Include field blanks in EPA Method 539 sampling procedures and clear guidance on what water 

systems and laboratories should do with associated samples if a field blank is positive, similar to the 

guidance that is included in EPA Method 537.

Response: Please see response to comment codes 31000 Hormones and 31010 EPA Method 539 - 

Hormones. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080
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31010 EPA Method 539 - Hormones Page 123 of 401

Comment ID: 32078

Comment Code: 31010

Comment: 4. EPA Method 539 is currently used by very few labs, but was used by one lab in

WaterRF project 4167, which included some of the UCMR3 analytes. Its performance was 

comparable to other hormone methods used in that study, but the method has not been thoroughly 

evaluated at the low MRLs and there is no provision in this method for field blanks. 

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32079

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 36010 EPA Method 537 Rev 1.1 - PFCs

Comment: Based on past experience, we expect EPA methods 539 and 537 to be rugged, but we 

question whether their performance has been demonstrated rigorously at the proposed LCMRL 

level. Laboratories would benefit from some time to bring the method on line and use them prior to 

UCMR3 (e.g. a shake-down period to work out the idiosyncrasies of these methods) and to gather 

additional information to inform MRL determination. EPA should work with the broader drinking 

water community data to collect additional data that would inform understanding of method 

performance and provide an opportunity to standardize improvements to these methods - this could 

take the form of a multi-laboratory method trial prior to finalizing UCMR3 or be an element of 

laboratory approval during UCMR3 preparatory phase.

Response: Please see response to comment codes 31010 EPA Method 539 - Hormones and 36010 

EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32083

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 36010 EPA Method 537 Rev 1.1 - PFCs

Comment: AWWA also recommends that EPA provide specific UCMR3 guidance for handling 

data when there is a positive field blank. Currently, EPA Method 537 requires a field blank, and a 

field blank is also appropriate for EPA Method 539 samples. The guidance in EPA Method 537 

requires invalidating results and recollecting samples if positive results are found in the field blank 

above 1/3 of the MRL and positive results are also found in samples, regardless of level. While we

think it unlikely that there will be many cases where field blanks exceed 1/3 of the MRLs proposed 

in UCMR3 for EPA Method 537 analytes, we believe this still has the potential to require 

unnecessary recollection and recommend that EPA modify the guidance to only require recollection 

if sample results are <10X the level found in the field blank. We believe this type of guidance is even 
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31010 EPA Method 539 - Hormones Page 124 of 401

more critical for EPA Method 539, in light of the very low MRLs proposed for some of the 

hormones. EPA also needs to be sure that the database will capture the necessary information on 

either sample rejection or relative field blank measurements.

Response: Please see response to comment codes 31010 EPA Method 539 - Hormones and 36010 

EPA Method 537 Rev 1.1 - PFCs.

While EPA will evaluate all field blank and other quality control data for the laboratories under 

contract to EPA to provide the small system monitoring, it is beyond the capabilities of the 

SDWARS to collect and evaluate this large quantity of data for the large system component. It is the 

responsibility of the PWS to assure that their laboratory only report data to SDWARS that meets all 

of the quality control requirements. EPA will conduct periodic audits of laboratories to assure that 

these requirements are understood and are being met. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32086

Comment Code: 31010

Other EPA Comment Codes and Descriptions: 36010 EPA Method 537 Rev 1.1 - PFCs

Comment: Appropriate MRLs? Sound technical reasons point to revisiting the MRLs included in 

the proposed UCMR3 notice. 

Excessively Low Reporting Levels Endanger the Credibility of the Data All but two of the proposed 

reporting levels are at sub-part per billion concentrations and many much lower. For example, all 

but two of the listed hormones are at sub- part per trillion levels (e.g., 17-ß-estradiol, 0.0004 ug/L 

and testosterone 0.0001 ug/L). There are recognized instances of laboratory sample contamination

of low-level hormone samples by laboratory technicians with good experimental technique but who 

were taking birth control at the time they processed samples. At these very low concentrations, the 

observations are very sensitive to the:

1. Competency of the laboratory with the analytical method,

2. Field and in-laboratory sample handling conditions and practices, and 

3. Contamination by experimental equipment and supplies. In California, an expert blue ribbon 

panel of toxicologists and chemists prepared a document for the State Water Resources Control 

Board (CEC Blue Ribbon Panel) where much of a chapter was devoted to the need for proper 

control and treatment of field and lab blanks for pharmaceuticals and hormones.[FN14:2010. 

California, State Water Resources Control Board. Monitoring Strategies for Chemicals of Emerging 

Concern (CECs) in Recycled Water, Recommendations of a Science Advisory Panel. June 25, 2010. 

(ftp://ftp.sccwrp.org/pub/download/DOCUMENTS/CECpanel/CECMonitoringInCA 

RecycledWater_FinalReport.pdf) This report would be a useful resource for EPA as it develops 

UCMR3 guidance for laboratory and field practices when handling samples for quantitation at these 

very low concentrations.
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31010 EPA Method 539 - Hormones Page 125 of 401

Specifically, for any MRL for the perfluorinated compounds and hormones that is < 5 ng/L, it is 

desirable to develop a mechanism for interpreting (or rejecting) data based on occurrence in field 

blanks compared to occurrence in the samples. UCMR3 guidance (and not just the method itself) 

should specify that water systems also collect a field blanks to ensure that any positive observations 

for these compounds are not the result of random laboratory or field contamination. These two 

methods have extensive discussion of laboratory blanks and protocols for ensuring that actual 

analysis of field samples is not conducted unless a lab blank is <1/3 the MRL. A similar mechanism 

is warranted to address contamination during sample collection for not only EPA Method 537, but 

also EPA Method 539, and that guidance should be expanded to minimize the need for 

recollections.

Response: Please see response to comment codes 31010 EPA Method 539 - Hormones and 36010 

EPA Method 537 Rev 1.1 - PFCs.
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January 2012

31050 Health Effects - Hormones Page 126 of 401

Comment Code: 31050 Health Effects - Hormones

Summary Response to Comments on Health Effects - Hormones: With regard to comments 

on how and why certain hormones were selected for UCMR 3 monitoring: following the publication 

of the draft CCL 3, additional data were evaluated. Based upon this re-evaluation with new data, 

EPA concluded that seven hormones (17 alpha-estradiol, 17 beta-estradiol, equilenin, equilin, estriol, 

estrone, and ethinyl estradiol) should be included in UCMR 3 monitoring because these 

contaminants are known or anticipated to occur in public water systems at levels of health concern; 

however, there is insufficient occurrence data available to permit EPA to make an informed 

regulatory determination at this time. EPA continues to actively work to evaluate the potential risks 

to human health and aquatic life posed by trace amounts of pharmaceuticals and personal care 

products in water. 

Individual Comments

Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31668

Comment Code: 31050

Other EPA Comment Codes and Descriptions: 31000 Hormones

Comment: May 2,2011

Water Docket U.S. Environmental Protection Agency Mail Code 282211T 1200 Pennsylvania 

Avenue, N.W. Washington, DC 20460

Re: Docket ID No. EPA-2009-0090 Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR 3) for Public Water Systems (76 Fed. Reg. 11713, March 3, 2011)

Ladies and Gentlemen:

Merck & Co., Inc. is pleased to submit these comments on the U.S. Environmental Protection 

Agency's (EPA) Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for 

Public Water Systems. EPA has published proposed monitoring requirements for 30 contaminants 

(76 Fed. Reg. 11713, March 3, 2011), most of which are on its Candidate Contaminant List 3 (CCL3) 

that was published in 2009. The Proposal makes available for public review and comment the 

proposed monitoring for evaluation of potential drinking water contaminants that should be 

investigated further for possible addition to the primary drinking water regulations. There are seven 

hormones, six of which are naturally occurring, that are included on proposed List 1 for assessment. 

Merck has reviewed the Proposal and the basis for including these hormones in UCMR 2 and has 

prepared the following comments to EPA. 

The justification for including several of the hormones selected for List 1 assessment monitoring 

does not sufficiently demonstrate concern for public health. 
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31050 Health Effects - Hormones Page 127 of 401

As presented at the Stakeholder Meeting Regarding Revisions to the Unregulated Contaminant 

Monitoring Regulation, equilin, estrone, and estriol are all included in the monitoring exercise based 

on "estrogenic hormonal response in post-menopausal women" and structural similarity to estradiol. 

There are many substances, naturally occurring and synthetic, with structural similarity to estrogen 

that could trigger receptor responses with varying potency. We do not believe that these 

characteristics alone justify inclusion and suggest they should be removed from the monitoring 

proposal. 

Furthermore, looking at the CCL3 list posted to the Agency website, we do not see testosterone or 

4-androstene-3, 17-dione included and question how these substances were introduced into the 

UCMR3 list. In addition, the above-cited presentation uses structural similarities to testosterone as 

the basis for inclusion of 4-androstene-3, 17-dione which we regard as insufficient evidence of 

potential for public health concern and propose that it be removed from the UCMR3 list.

Response: The structural similarity among equilin, estrone, and estriol with estradiol was only one 

aspect that led to these compounds being included in the current Candidate Contaminant List (CCL 

3). The Agency considered the best available data and information on health effects and occurrence 

to evaluate thousands of unregulated contaminants. EPA used a multi-step process that resulted in 

the selection of 116 candidates for the final CCL 3. The final CCL 3 includes 104 chemicals or 

chemical groups and 12 microbiological contaminants. 

The androgens were selected because of their health impacts and the occurrence data currently 

available. Please see response to comment code 31000 Hormones. 

Commenter Name: Barbara Schulze

Commenter Organization: Merck

Letter ID: 0064

Comment ID: 31670

Comment Code: 31050

Comment: A study published in 2010 evaluated potential human exposure to estrogenic 

compounds in drinking water including natural estrogens, prescribed endogenous estrogens, and 

prescribed synthetic estrogens (EE2).[FN5: Caldwell, D.1., Mastrocco, F., Nowak, E., Johnston, 1., 

Yekel, H., Pfeiffer, D., Hoyt, M., DuPlessie, B., and Anderson, P. "An Assessment of Potential 

Exposure and Risk from Estrogens in Drinking Water." Environ. Health Perspectives. 118, no 3,

March 2010, pp. 338-344.] This study, which assumed no removal of estrogenic compounds by 

drinking water treatment, used the Pharmaceutical Assessment and Transport Evaluation (PhATE) 

model to predict nationwide estimates of drinking water exposure to the target estrogenic 

compounds for adults and children. The predicted margins of safety (MOS) for an adult's exposure 

to total prescribed estrogens in drinking water vary from about 135 to > 17,000, depending on the 

acceptable daily intake (ADI) for a specific estrogen. MOS for exposure to total estrogens in 

drinking water are about 2 times lower than MOS for prescribed estrogens. Depending on the ADI 

that is used, MOS for young children range from 28 to 5,120 for total estrogens (including both 

prescribed and naturally occurring sources) in drinking water. This study concludes that total 

estrogens (natural and synthetic) in public drinking water supplies are not causing adverse effects in 

U.S. residents, including sensitive subpopulations. 
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31050 Health Effects - Hormones Page 128 of 401

A second study, published in 2011, resulted in the same conclusion for synthetic estrogen used in 

oral contraceptives.[FN6: Op cit., Wise, A., O'Brien, K., and Woodruff, T., 2011.] This study 

concluded that the risks of EE2 in drinking water are negligible.

While there is considerable public concern regarding the presence of pharmaceutical compounds in 

public water supplies, there is a significant amount of data that supports the conclusions of EPA's 

draft 2008 CCL3 list - that APIs in drinking water including the seven hormones on the proposed 

UCMR3 list are typically not present at concentrations that merit nationwide testing of all public 

drinking water supplies. Merck does not object to such testing, but it appears to be a poor use of 

EPA's resources to analyze finished drinking water for these hormones. Given the concerns with 

viruses and pathogenic bacteria in drinking water, it would be prudent to focus more monitoring on 

these classes of drinking water contaminants rather than on the hormones currently listed in the 

proposed UCMR3. 

Response: Please see response to comment code 31050 Health Effects - Hormones. 

Commenter Name: Stephen Brooks 

Commenter Organization: Pfizer Inc.

Letter ID: 0071

Comment ID: 31680

Comment Code: 31050

Comment: Pfizer appreciates the opportunity to submit these comments on the U.S.

Environmental Protection Agency's (USEPA) Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR 3) for Public Water Systems. There are seven hormones that are 

included on proposed List 1 for assessment. Pfizer has carefully evaluated the Proposal and the basis 

for which these hormones were included in the UCMR 3. As a result of our review, we have 

concluded that there does not appear to be adequate justification for including the hormones on List 

1. Our reasoning is set forth in the attached letter.

To summarize, the process by which the seven hormones were selected for the UCMR 3 appears to 

lack transparency and, from what we were able to glean, the information put forth fails to adequately 

demonstrate a basis for a public health concern. Furthermore we offer scientific evidence to the 

contrary, that even assuming worst-case, exposure to estrogens in drinking water does not present a 

public health concern. Therefore, the seven hormones proposed to the UCMR 3 should be 

removed. 

May 2, 2011 Water Docket U.S. Environmental Protection Agency Mail Code 282211T 1200 

Pennsylvania Avenue, N.W. Washington, DC 20460

Re: Docket ID No. EPA-2009-0090 Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR 3) for Public Water Systems (76 Fed. Reg. 11713, March 3, 2011)

Ladies and Gentlemen:

Pfizer appreciates the opportunity to submit these comments on the U.S. Environmental Protection 

Agency’s (USEPA) Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

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31050 Health Effects - Hormones Page 129 of 401

for Public Water Systems. EPA has published proposed monitoring requirements for 30 

contaminants (76 Fed. Reg. 11713, March 3, 2011) (Proposal), most of which are on its Candidate 

Contaminant List 3 ("CCL3") that was published in 2009.

The Proposal makes available for public review and comment the proposed monitoring for 

evaluation of potential drinking water contaminants that should be investigated further for addition 

to the primary drinking water regulations. There are seven hormones that are included on proposed 

List 1 for assessment. Pfizer has carefully evaluated the Proposal and the basis for which these

hormones were included in the UCMR 3. As a result of our review, we have concluded that there 

does not appear to be adequate justification for including the hormones on List 1. Our reasoning is 

set forth below. 

Scientific Basis

As presented at the Stakeholder Meeting Regarding Revisions to the Unregulated Contaminant 

Monitoring Regulation [FN1: "UCMR 3 Potential Contaminants and Rationale - Chemicals" made 

by John Martin, The Cadmus Group, Inc. at the Stakeholder Meeting Regarding Revisions to the 

Unregulated Contaminant Monitoring Regulation, April 7, 2010 (EPA- HQ-2009-0090-0031)], 

equilin, estrone, and estriol are all included in the monitoring exercise based on "estrogenic 

hormonal response in post-menopausal women" and structural similarity to estradiol. These 

characteristics alone do not adequately demonstrate a public health concern. 

To the contrary, we summarize here the findings of a study published in 2010 that evaluated 

potential human exposure to estrogenic compounds in drinking water including natural estrogens, 

prescribed endogenous estrogens, and prescribed synthetic estrogens (ethinyl estradiol - EE2) [FN2: 

Caldwell, D.J., Mastrocco, F., Nowak, E., Johnston, J., Yekel, H., Pfeiffer, D., Hoyt, M., DuPlessie, 

B., and Anderson, P. "An Assessment of Potential Exposure and Risk from Estrogens in Drinking 

Water." Environ. Health Perspectives. 118, no 3, March 2010, pp. 338-344].

This study, which assumed no removal of estrogenic compounds by drinking water treatment, used 

the Pharmaceutical Assessment and Transport Evaluation (PhATE) model to predict nationwide 

estimates of drinking water exposure to the target estrogenic compounds for adults and children. 

The predicted margins of safety (MOS) for an adult’s exposure to total prescribed estrogens in 

drinking water vary from about 135 to >17,000, depending on the acceptable daily intake (ADI) for 

a specific estrogen. MOS for exposure to total estrogens in drinking water are about 2 times lower 

than MOS for prescribed estrogens. Depending on the ADI that is used, MOS for young children 

range from 28 to 5,120 for total estrogens (including both prescribed and naturally occurring 

sources) in drinking water. This study concluded that, assuming worst-case, total estrogens (natural 

and synthetic) in public drinking water supplies are not causing adverse effects in U.S. residents, 

including sensitive subpopulations. 

A second study, published in 2011, resulted in the same conclusion for synthetic estrogen used in 

oral contraceptives [FN3: Wise, A., O’Brien, K., and Woodruff, T., "Are Oral Contraceptives a 

Significant Contributor to the Estrogenicity of Drinking Water?" Env. Sci. & Technol., 45, no. 1, 

2011, pp. 51-60]. This study concluded that the risks of EE2 in drinking water are negligible. 
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31050 Health Effects - Hormones Page 130 of 401

With regard to testosterone and 4-androstene-3,17-dione, looking at the CCL3 list posted to the 

EPA website, we do not see either included and question how these substances were introduced into 

the exercise. In addition, the above-cited presentation gives little support to the public health 

concerns of testosterone and uses structural similarities to testosterone as the basis for inclusion of 

4-androstene-3,17-dione. 

In both cases, testosterone and 4-androstene-3,17-dione, insufficient evidence of potential for public 

health concern is presented and therefore, they should be removed from consideration on the List 1 

assessment.

Summary

The process by which the seven hormones were selected for the UCMR 3 appears to lack 

transparency and, from what we were able to glean, the information put forth fails to adequately 

demonstrate a basis for a public health concern. Furthermore we offer scientific evidence to the 

contrary, that even assuming worst-case, exposure to estrogens in drinking water does not present a 

public health concern. Therefore, the seven hormones proposed to the UCMR 3 should be 

removed. 

We appreciate the opportunity to offer these comments. If you have any questions about them or 

the references offered, please do not hesitate to contact me.

Sincerely,

Stephen Brooks 

Response: Please see response to comment code 31050 Health Effects - Hormones. 

Commenter Name: Neil Parke

Commenter Organization: Eli Lilly and Company 

Letter ID: 0076

Comment ID: 31695

Comment Code: 31050

Comment: Eli Lilly and Company ("Lilly") is pleased to submit the following comments on the U.S. 

Environmental Protection Agency’s (EPA) Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR 3) for Public Water Systems. EPA has published proposed monitoring 

requirements for 30 contaminants (76 Fed. Reg. 11713, March 3, 2011) (Proposal).

We appreciate EPA’s consideration of these comments. If you have any questions about Lilly’s 

comments, please contact me.

Sincerely, Neil Parke, M.A. Global HSE Consultant Eli Lilly and Company 317-276-7201

May 2, 2011 Water Docket U.S. Environmental Protection Agency Mail Code 282211T 1200 

Pennsylvania Avenue, N.W. Washington, DC 20460 Re: Docket ID No. EPA-2009-0090 Revisions 
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31050 Health Effects - Hormones Page 131 of 401

to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems (76 

Fed. Reg. 11713, March 3, 2011)

Ladies and Gentlemen:

Eli Lilly and Company ("Lilly") is pleased to incorporate and submit the following comments on the 

U.S. Environmental Protection Agency’s (EPA) Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR 3) for Public Water Systems. EPA has published proposed 

monitoring requirements for 30 contaminants (76 Fed. Reg. 11713, March 3, 2011) (Proposal), most 

of which are on its Candidate Contaminant List 3 (CCL3) that was published in 2009. The Proposal 

makes available for public review and comment the proposed monitoring for evaluation of potential 

drinking water contaminants that should be investigated further for addition to the primary drinking 

water regulations. There are seven hormones, six of which are naturally occurring, that are included 

on proposed List 1 for assessment. Lilly has carefully reviewed the Proposal and the basis for 

including these five hormones in UCMR 3 and is pleased to offer these comments.

Lilly is a research-based corporation engaged in the development, manufacturing and marketing of 

human and animal health pharmaceutical products on a global basis. Within the United States, Lilly 

owns and operates facilities which rely upon safe drinking water. Several water supplies that service 

Lilly sites are expected to be subject to the proposed UCMR 3 rule. Because hormones are a class of 

chemicals that has been evaluated for inclusion in the UCMR 3, EPA’s evaluation process for 

determination of which hormones are included on the proposed UCMR 3 is of considerable 

importance to Lilly. 

Lilly offers the following comments on specific aspects of the proposed UCMR 3. 

1. The justification for including several of the hormones selected for List 1 assessment monitoring 

does not sufficiently demonstrate concern for public health. 

As presented at the Stakeholder Meeting Regarding Revisions to the Unregulated Contaminant 

Monitoring Regulation1, equilin, estrone, and estriol are all included in the monitoring exercise 

based on "estrogenic hormonal response in post-menopausal women" and structural similarity to 

estradiol. There are many substances, naturally-occurring and synthetic, with structural similarity to 

estrogen that could trigger receptor responses with varying potency. Lilly does not believe that these 

characteristics alone justify inclusion and suggest that should be removed from the monitoring 

proposal. Furthermore, looking at the CCL3 list posted to the Agency website, Lilly does not see 

testosterone or 4- androstene-3,17-dione included, and questions how these substances were 

introduced into the exercise. In addition, the above-cited presentation uses structural similarities to 

testosterone as the basis for inclusion of 4- androstene-3,17-dione which Lilly regards as insufficient 

evidence of potential for public health concern and proposes that it be removed from consideration. 

2. The justification for including the seven hormones selected for List 1 assessment monitoring does 

not appropriately recognize the fact that all but one occur naturally and are excreted in urine.

EPA has included the following seven hormones on the proposed UCMR 3 analyte list: 17-?-

estradiol, 17-?-ethynylestradiol (EE2), estriol, estrone, testosterone, 4-androstene- 3,17-dione and 

equilin (76 Fed. Reg. 11718). Six of these hormones occur naturally - only EE2 is a synthetic 

hormone. EPA’s "Possible Contaminants for Inclusion on UCMR 3-Information Compendium" 
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31050 Health Effects - Hormones Page 132 of 401

(EPA 815- B-10-002) (Information Compendium) describes the "background" for each of these 

hormones and lists all seven as "used in pharmaceuticals." While this statement is accurate, it is 

incomplete and misleading. In fact, the principal source of the six naturally occurring hormones in 

the effluents of publicly owned treatment works (POTWs) and surface water used as drinking water 

supplies is human and animal excretion of these chemicals.[FN1: Wise, A., O’Brien, K., and 

Woodruff, T., "Are Oral Contraceptives a Significant Contributor to the Estrogenicity of Drinking 

Water?" Env. Sci. & Technol., 45, no. 1, 2011, pp. 51-60. Water Docket, Docket ID No. EPA-2009-

0090] It is misleading to the public and the drinking water industry to imply that the principal source 

of these six hormones is their use in pharmaceutical products. Lilly requests that EPA clarify that all 

of hormones on the UCMR 3 list with the exception of EE2 are naturally occurring and are used in 

pharmaceuticals.

3. The inclusion of the seven hormones on the proposed UCMR 3 list is not justified by their 

frequency of occurrence in untreated source water and the risk associated with the concentrations 

that have been measured in such waters.

EPA’s contaminant candidate list 3 (CCL3) methodology evaluated 287 active pharmaceutical 

ingredients (API) as candidate CCL3 contaminants (the universe). 

Approximately 10% of these APIs were included on the preliminary CCL. The Agency concluded 

that only one API, nitroglycerin, should be proposed for inclusion on the CCL3 (73 Fed. Reg. 9652). 

No hormones were identified for inclusion on the proposed CCL3. However, when the final rule 

was published, five of the hormones in the UCMR 3 proposal (testosterone and 4-androstene-3,17-

dione are not on current CCL3) were identified on the final CCL3 list, even though the Agency had 

previously concluded that they were not found at sufficient frequency and at concentrations that 

presented a human health risk through the drinking water pathway. The Agency states that these 

hormones were added to CCL3 because they were "known or anticipated to occur in public water 

systems" (74 Fed. Reg. 51855). However, contrary to this assertion, the data summarized in EPA’s

Information Compendium shows that these hormones were not detected in finished drinking water 

[FN2: Snyder, S.A., R.A. Trenholm, E.M. Snyder, G.M. Bruce, R.C. Pleus, and J.D.C. Hemming. 

2008. Toxicological Relevance of EDCs and Pharmaceuticals in Drinking Water. AWWA.] but were

found at low concentrations and at low frequency in source water.

EPA’s Information Compendium summarizes available data on the frequency of occurrence of each 

of the seven hormones proposed for monitoring. None of the seven hormones have ever been 

measured in finished drinking water based on EPA’s data summaries in the Information 

Compendium.[FN3: Snyder, et al., 2008.] Furthermore, their frequency of occurrence in surface and 

ground water supplies is, in general, low to very low.

Based on the data summarized in the Information Compendium, most of the measured ambient 

surface water concentrations of these seven hormones are substantially lower than the human health 

risk levels identified for the chemicals. Finally, because oxidative treatment (e.g., chlorination) 

rapidly eliminates that estrogenic activity of these chemicals (see Sedlak, DL and von Gunten, U. 

2011. The chlorine dilemma. Science 331: 42-43), it is unlikely that any of them would persist 

through conventional drinking water treatment. 

A study published in 2010 evaluated potential human exposure to estrogenic compounds in drinking 

water including natural estrogens, prescribed endogenous estrogens, and prescribed synthetic 
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January 2012

31050 Health Effects - Hormones Page 133 of 401

estrogens (EE2).[FN4: Caldwell, D.J., Mastrocco, F., Nowak, E., Johnston, J., Yekel, H., Pfeiffer, D., 

Hoyt, M., DuPlessie, B., and Anderson, P. "An Assessment of Potential Exposure and Risk from 

Estrogens in Drinking Water." Water Docket, Docket ID No. EPA-2009-0090] This study, which 

assumed no removal of estrogenic compounds by drinking water treatment, used the Pharmaceutical 

Assessment and Transport Evaluation (PhATE) model to predict nationwide estimates of drinking 

water exposure to the target estrogenic compounds for adults and children. The predicted margins 

of safety (MOS) for an adult’s exposure to total prescribed estrogens in drinking water vary from 

about 135 to > 17,000, depending on the acceptable daily intake (ADI) for a specific estrogen. MOS 

for exposure to total estrogens in drinking water are about 2 times lower than MOS for prescribed 

estrogens. Depending on the ADI that is used, MOS for young children range from 28 to 5,120 for 

total estrogens (including both prescribed and naturally occurring sources) in drinking water. This 

study concludes that total estrogens (natural and synthetic) in public drinking water supplies are not 

causing adverse effects in U.S. residents, including sensitive subpopulations. 

A second study, published in 2011, resulted in the same conclusion for synthetic estrogen used in 

oral contraceptives.[FN5: Op cit., Wise, A., O’Brien, K., and Woodruff, T., 2011.] This study 

concluded that the risks of EE2 in drinking water are negligible.

While there is considerable public concern regarding the presence of pharmaceutical compounds in 

public water supplies, there is a significant amount of data that supports the conclusions of EPA’s 

draft 2008 CCL3 list - that APIs in drinking water including the seven hormones on the proposed 

UCMR 3 list are typically not present at concentrations that merit nationwide testing of all public 

drinking water supplies. Lilly does not object to such testing, but it appears to be a poor use of 

EPA’s resources to analyze finished drinking water for these hormones. Given the concerns with 

viruses and pathogenic bacteria in drinking water, it would be prudent to focus more monitoring on 

these classes of drinking water contaminants rather than on the hormones currently listed in the 

proposed UCMR 3. 

Response: Please see response to comment code 31050 Health Effects - Hormones. 
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31600 Testosterone Page 134 of 401

Comment Code: 31600 Testosterone

Individual Comments

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31597

Comment Code: 31600

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: * In the event EPA believes the potential health effects surrounding low-level exposure 

to hexavalent chromium (Cr-VI) warrant its addition to the list, then the agency should add Cr-VI to 

UCMR-3 (See Comment 2, Hexavalent Chromium).

* If EPA adds Cr-VI to the UCMR-3 list, then it should remove testosterone and also consider 

removing the other hormones not on CCL 3 from the list for the following reasons: 

- Hormones in general were not captured in the initial screening process for CCL 3. Based on the 

research to date, the occurrence of hormones in water appears to be more a concern to aquatic life 

than human health. 

Response: EPA believes that monitoring for testosterone and 4- androstene-3,17-dione is justified. 

Published articles show the occurrence of testosterone and 4- androstene-3,17-dione in surface 

waters and 4- androstene-3,17-dione in drinking water. Testosterone and 4- androstene-3,17-dione 

have been shown to be relatively resistant to oxidation. EPA has further described its rationale for 

including these contaminants in the proposed rule on March 3, 2011 (76 FR 11713). Please see 

response to comment codes 31000 Hormones and 38100 Chromium-6.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31767

Comment Code: 31600

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: 2. Hexavalent Chromium 

Should EPA include Cr-VI and if Cr-VI is added, what should be removed from list?

AMWA recommends that EPA include Cr-VI in UCMR-3 if the agency can clearly state that Cr-VI 

poses a significant public health risk at the low levels likely to be found in finished drinking water. 

Including Cr-VI in UCMR-3 will result in a reliable, nationally consistent dataset not currently 

available. The Cr-VI data obtained from the UCMR monitoring will be appropriate for informing 

the decision about whether to regulate Cr-VI on its own, rather than as total chromium. As Cr-VI is 
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31600 Testosterone Page 135 of 401

not currently regulated with its own MCL under the SDWA, AMWA believes that it is appropriate 

and allowable for inclusion in the UCMR. 

If Cr-VI is added to the list, AMWA recommends that EPA remove testosterone and also consider 

removing the other hormones from UCMR because: 

- hormones in general were not captured in the screening process for CCL 3. Based on the research 

to date, the occurrence of hormones in water appears to be more a concern to aquatic life than 

human health; 

- there is a likelihood at the proposed reporting levels to find testosterone and some of the other 

hormones occurring at very low levels; and

- due to the low levels of occurrence likely to be found and lack of field blanks identified in the 

analytical method, there may well be false positive measurements.

Response: EPA believes that monitoring for testosterone is justified. EPA has described its 

rationale for including this contaminant in the proposed rule on March 3, 2011 (76 FR 11713). A 

number of published articles show the occurrence of testosterone in surface waters and testosterone 

has been shown to be relatively resistant to oxidation. Sec-butylbenzene and n-propylbenzene have 

been removed from the list of contaminants to be monitored. Chromium-6 (hexavalent chromium) 

and total chromium have been added to the list of contaminants to be monitored. 

Please see response to comment codes 31000 Hormones and 38100 Chromium-6.
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32000 Volatile Organic Compounds (VOCs) Page 136 of 401

Comment Code: 32000 Volatile Organic Compounds (VOCs)

Individual Comments

Commenter Name: Roger Sokol 

Commenter Organization: NY State Dept. of Health

Letter ID: 0065

Comment ID: 31676

Comment Code: 32000

Other EPA Comment Codes and Descriptions: 34000 Metals

Comment: Proposed list of contaminants 

The BWSP also supports inclusion of molybdenum, strontium, bromomethane and chloromethane 

on the UCMR3 contaminant list. All 4 of these contaminants are associated with hydrofracturing in 

the Marcellus Shale. Occurrence data on these contaminants will fill a data gap relative to this 

controversial process. 

Response: EPA appreciates your support and has included molybdenum, strontium, 

bromomethane, and chloromethane on the UCMR 3 Assessment Monitoring list. 

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31864

Comment Code: 32000

Comment: * Unregulated VOCs: This would be an opportunity for EPA to improve coordination 

between the new Drinking Water Strategy and UCMR3 regarding volatile organic chemicals (VOCs). 

There are nine VOCs proposed for sampling under UCMR3 and eight unregulated carcinogenic 

VOCs under consideration for future regulation as part of the Drinking Water Strategy contaminant 

group effort. However, there are only three VOCs that overlap between these two lists. Unless EPA 

feels it already has adequate occurrence data on all the VOCs under consideration, sampling under 

the UCMR3 would provide additional occurrence information on VOCs to support the regulatory 

development process. 

Response: EPA has only developed analytical methods for four of the eight unregulated 

carcinogenic VOCs, and only three of those four can be analyzed using Method 524.3, the method 

that EPA has proposed for VOCs in UCMR 3. Those three VOCs, 1,3-butadiene, 1,1-

dichoroethane, and 1,2,3-trichloropropane have been proposed for inclusion in UCMR 3. 

Nitrobenzene, the fourth unregulated VOC for which EPA has an analytical method was monitored 

in UCMR 1.
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32000 Volatile Organic Compounds (VOCs) Page 137 of 401

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31865

Comment Code: 32000

Other EPA Comment Codes and Descriptions: 34000 Metals

Comment: * New York Recommendations: New York State specifically supports some listed 

contaminants that are a priority for them because of local occurrence or potential occurrence. New 

York supports inclusion of molybdenum, strontium, bromomethane and chloromethane on the 

UCMR3 contaminant list. All four of these contaminants are associated with hydrofracturing in the 

Marcellus Shale. Occurrence data on these contaminants will fill a data gap relative to this

controversial gas extraction process.

Response: EPA appreciates your support and has included molybdenum, strontium, 

bromomethane, and chloromethane on the UCMR 3 Assessment Monitoring list. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32067

Comment Code: 32000

Comment: [Table 1. Relevant Rationale for Removing Specific Contaminants from UCMR3 [See 

PDF Docket ID: EPA-HQ-OW-2009-0090-0080.1]] VOCs / EPA 524.3 / Chloromethane, 1,3-

butadiene, Chlorodifluoromethane / Unlikely to Occur - These analytes are gases with boiling points 

below 0°C. Limited available data do not suggest widespread occurrence in water is to be expected.

Response: Although the three VOCs you cite are gases at Standard Temperature and Pressure 

(STP), the Henry's Law Constant (HLC) for a contaminant is a better indicator than is boiling point 

for describing the degree to which a VOC volatilizes to air relative to how much remains in water. 

The HLCs for chloromethane, 1,3-butadiene, and chlorodifluoromethane at 22-25 degrees Celsius 

are (ChemIDPlus Lite, 2011):

* chloromethane: 0.00882 atm-m3/mol

* 1,3-butadiene: 0.074 atm-m3/mol

* chlorodifluoromethane: 0.0406 atm-m3/mol

For reference, the HLC for vinyl chloride, a regulated carcinogenic VOC that is also a gas at STP 

(boiling point = -13 degrees Celsius), is 0.0278 atm-m3/mol. The HLC values for chloromethane 

and chlorodifluoromethane, which are less than that of vinyl chloride, indicate that chloromethane 

and chlorodifluoromethane partition to air from water to a lesser degree than does vinyl chloride. 

Chloromethane and chlorodifluoromethane are thus more likely to remain in water than is vinyl 

chloride. Thus EPA believes that these data for chloromethane and chlorodifluoromethane justify 

their continued inclusion on UCMR 3. EPA has described its rationale for including these 

contaminants in the proposed rule on March 3, 2011 (76 FR 11713).
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The HLC for 1,3-butadiene is approximately 2.7 times greater than that for vinyl chloride, indicating 

that 1,3-butadiene will partition to air from water to a modestly greater degree than does vinyl 

chloride. However, since it is a carcinogen that is produced and used in very large quantities in the 

United States, EPA believes that inclusion of 1,3-butadiene on UCMR 3 is justified. In addition, the 

analysis of chloromethane, 1,3-butadiene, and chlorodifluoromethane is accomplished using EPA 

Method 524.3 along with five additional VOCs that are included in UCMR 3. Research on the cost 

for the analysis of VOCs by EPA Method 524.3 indicates that there is little or no incremental cost 

increase for analyzing eight VOCs as opposed to five VOCs.

Reference: ChemIDPlus Lite. 2011. National Library of Medicine, National Institutes of Health, 

Department of Health and Human Services, Available on the Internet at: 

http://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp 
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32010 EPA Method 524.3 - VOCs Page 139 of 401

Comment Code: 32010 EPA Method 524.3 - VOCs

Individual Comments

Commenter Name: Dennis O'Sullivan

Commenter Organization: DoD Safe Drinking Water Act Services Steering Committee

Letter ID: 0048

Comment ID: 31611

Comment Code: 32010

Comment: [1] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 524.3: 16 

Para#/ Line# (Methods documents): METHOD 524.3: 8.4 Comment Classification C/M/S/A: S 

Comment: Temperature and hold time requirements vary without explanation. 

Rationale: Why are the shipping and laboratory storage temperature requirements different? Samples 

are to be shipped at less than or equal to 10°C, but yet the laboratory must store the samples once 

received at less than or equal to 6°C.

[2] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 524.3: 23; 27; 28 Para#/ 

Line# (Methods documents): METHOD 524.3: 9.3.7.3; 9.3.8.2; 10.1.10; 10.2.1 Comment 

Classification C/M/S/A: S

Comment: Sliding scale of acceptance criteria over the quantitation range introduces additional 

uncertainty to the analysis.

Rationale: Since the low-level CCC concentration is within the quantitation range (1 - 2 times MRL), 

it is not justified to have varying acceptance criteria within the quantitation range. It cannot be 

determined at what point the uncertainty changes from 50 to 30%. It is recommended that the same 

acceptance criteria be used for each standard, regardless of the concentration. This same comment 

applies to the evaluation of recoveries and RPDs of the field duplicates and LFSM and LFSMDs 

(Section 9.3.7.3 and 9.3.8.2), and CAL standards (10.1.10).

[3] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 524.3: 23 Para#/ Line# 

(Methods documents): METHOD 524.3: 9.3.7.3 Comment Classification C/M/S/A: S 

Comment: Concentrations less than the MRL are used to correct the LFSM and LFSMD are 

qualitative and not reported in the native samples. 

Rationale: Values below the MRL are qualitative and may not be accurate enough for data reporting. 

As a result, only concentrations greater than the MRL are reported in native samples. It is 

recommended that LFSM and LFSMD values only be adjusted using values reported in the native 

samples (between the MRL and highest calibration standard). 

[4] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 524.3: 27 Para#/ Line# 

(Methods documents): METHOD 524.3: 10.1.10 Comment Classification C/M/S/A: S
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32010 EPA Method 524.3 - VOCs Page 140 of 401

Comment: The acceptance criteria calibration curve are not provided.

Rationale: The criteria (e.g., %RSD, correlation coefficient) used for evaluating the calibration curve 

that is generated by the calibration standards is not defined by the method. It is recommended 

criteria for the curve be included along with the requirements for each calibration standard. 

Response: [1] In EPA's experience, water samples may not be able to be maintained at 6 deg. C 

during shipment in some geographic locations and under some seasonal temperature variations. 

Therefore, to limit the number of rejected samples based on shipping temperatures, EPA has 

expanded the acceptable temperature for shipping (not to exceed 48 hours from sampling) to 10 

deg. C. However, upon sample receipt refrigerated storage at < 6 deg. C is required. In the 

development of Method 522, EPA conducted sample storage studies under these expanded 

temperature ranges to ensure that 1,4-dioxane is not unacceptably compromised during the shipping 

and storage period. 

[2] EPA has defined the Minimum Reporting Limit (MRL) for all UCMR 3 analytes and methods as 

the concentration that can be monitored within of 50 - 150 % of the true value. The precision and 

accuracy of chemical analysis is a function of the concentration being measured, therefore, it is valid 

to specify data quality objectives that take this fact into account and change the data quality 

requirements to a level consistent with the performance of each method for concentrations 

exceeding the MRL.

[3] Meaningful LFSM data at or near the MRL can only be obtained if native amounts are 

subtracted. A LFSM fortified at the MRL in a sample where the native amount is just below the 

MRL will lead to the false conclusion that there is a matrix bias unless the native amount is 

subtracted. The Minimum Reporting Limit (MRL) is simply the lowest concentration that can be 

reported in a field sample. The quality control aspects, both qualitative and quantitative, are based 

upon the MRL. Calibration standards are run down to the MRL, reagent blanks are evaluated 

relative to the MRL. However, statistical evaluations of data quality, such as the LFSM and LFSMD, 

would be biased if values below the MRL were not incorporated. 

[4] Criteria such as %RSDs or correlation coefficients provide limited indications of the quality of 

the calibration curve. In both cases, these measures minimize what may be significant errors at low 

concentrations. Methods used for the analysis of drinking water, where accurate low concentration 

calibration is essential, use the procedure detailed in section 10.2.3 which requires each calibration 

standard to be compared back to the calibration curve and must be within 30% of their true value. 

This is a far better method of assuring the quality of the calibration curve. 

Commenter Name: Karen A. Randazzo 

Commenter Organization: Suffolk County Water Authority (SCWA) 

Letter ID: 0081

Comment ID: 31701

Comment Code: 32010

Comment: Please see the attached. Thank you.
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January 2012

32010 EPA Method 524.3 - VOCs Page 141 of 401

Water Docket Environmental Protection Agency MaiI Code 282211T 1200 Pennsylvania Av., NW

Washington, DC 20460 Laboratory: 260 Motor Parkway, Hauppauge, New York 11788-5132 (631) 

563-0259 Fax (631) 563-0357 Attention Docket ID Number OW-2009-0090

Re: Revisions to Unregulated Contaminant Monitoring Regulation (UCMR 3); Proposed Rule-FR 

3/3/11

Dear Sir or Madame:

On behalf of the Suffolk County Water Authority (SCWA), I am pleased to present comments on 

the proposed regulation. 

The SCWA is the largest groundwater supplier in the nation, and has a long history of providing 

comprehensive drinking water monitoring and research as well as being a leader in groundwater 

protection programs. The SCWA has a nationally recognized laboratory devoted solely to 

monitoring the source water we serve our 1.2 million customers in Suffolk County, Long Island. 

Long Island was one of the first designated Sole Source Aquifer systems in the United States, and is 

considered to be one of the most intensively used and critical Aquifer systems in the country. 

A review of the minimum reporting levels (MRLs) listed in the proposed regulation indicates that 

several analytes in Method 524.3 had lower reporting levels than those specified in EPA Method 

524.3, Rev 1.0, June 2009.

Response: LCMRLs using SIM were not presented in Method 524.3. The MRLs for all of the 

contaminants listed in UCMR 3 were determined using a statistical evaluation of LCMRL data from 

multiple analytical laboratories that used the more sensitive SIM or Selected Ion Storage (SIS) modes 

allowed in EPA Method 524.3.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31745

Comment Code: 32010

Other EPA Comment Codes and Descriptions: 36010 EPA Method 537 Rev 1.1 - PFCs

Comment: 7. The definition of Field Reagent Blank (FRB) differs between 524.3 and 537, both 

UCMR3 methods. 537 requires that the FRB be opened in the field and transferred to the container. 

However method 524.3 states "FRB - 524.3" An aliquot of reagent water that is placed in a sample 

container in the laboratory and treated as a sample in all respects, including shipment to the 

sampling site, exposure to sampling site conditions, storage, preservation, and all analytical 

procedures. The purpose of the FRB is to determine if method analytes or other interferences are 

introduced into the samples during transport and storage.... Do not open FRBs in the field; FRBs 

must remain sealed until analysis." Is it the intention to have the same "sample type" treated

differently for different UCMR3 methods?

Response: The differing procedures for handling field blanks results from the differing probable 

sources of sample contamination. In the case of Method 537 (hormones) the most likely source of 
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January 2012

32010 EPA Method 524.3 - VOCs Page 142 of 401

contamination is from samplers and laboratory people that handle the samples and are taking 

hormone replacement or adjustment medications. In the case of Method 524.3 (VOCs) the 

compounds are much more volatile than the hormones and are more likely to enter the samples 

through the bottle seal during transport and storage. Opening the volatile samples would result in a 

headspace being formed, causing a loss of dissolved volatile compounds. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32075

Comment Code: 32010

Comment: 1. EPA Method 524.3 is a brand new volatile organic compound method with some 

significant differences from method EPA Method 524.2., in particular the use of SIM for a large 

number of analytes.

Response: Method 524.3 is a revision of Method 524.2, which has been in use since it was last 

revised in 1995. Selected Ion Monitoring (SIM) is a technique that has been available for many years. 

The reason that it has not been previously incorporated into methods such as 524.2 is a lack of QC 

requirements in Method 524.2 that are necessary to assure that SIM segments are properly timed 

throughout the chromatographic run. Method 524.3 contains this needed QC and therefore, has all 

of the procedures necessary to assure data quality.
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January 2012

32020 Other Methods - VOCs Page 143 of 401

Comment Code: 32020 Other Methods - VOCs

Individual Comments

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31758

Comment Code: 32020

Other EPA Comment Codes and Descriptions: 32100 1,2,3-Trichloropropane 

Comment: 21. The purpose of UCMR monitoring is to establish occurrence at levels relevant to the 

HRL. Given the low HRL (0.005 ug/L) for 1,2,3-TCP and the availability since 2002 of a method 

(California purge and trap method) capable of measuring at or below the HRL, EPA should 

consider using this method (MRL of ~ 0.005 ug/L - See the table below) in lieu of 524.3 (MRL of 

0.03 ug/L) for 1,2,3-TCP. In UCMR1, EPA had all utilities analyze for nitrobenzene by method 

524.2 (MRL of 8 ug/L) under list 1 and a subset use method 526 (MRL of 0.5 ug/L) under list 2 due 

to the low HRL. There is thus a precedent for this recommendation. If not, EPA may be faced with 

estimating occurrence at relevant levels (e.g. <0.03 ug/L), with significant cost implications for 

utilities.

Listed below are MDL determinations over 9 day periods for two individual analysts for the 

California method, with spiking at the HRL level of 0.005 ug/L. This demonstrates that the cited 

method is reliable and sufficiently sensitive to be used for this analyte. There are currently numerous 

labs certified for this method for compliance monitoring in California. 

[Table: see PDF docket ID EPA-HQ-OW-2009-0090-0047]

Thank you for your consideration of our comments. If you have any questions or require 

clarification of the comments please do not hesitate to contact the undersigned. 

Sincerely yours, Andrew Eaton, PhD Technical Director/Vice President

Response: There are a number of health-based values currently listed in IRIS for 1,2,3-

trichloropropane. These range from non-cancer impacts of 28 μg/L to 42 μg/L, and for 10^-5 

cancer end points ranging from 0.01 μg/L to 0.05 μg/L. For CCL 3, cancer-based HRLs were 

calculated at the 10^-6 risk level; thus the HRL of 0.005 μg/L (it corresponds to the value of 0.05 

μg/L which is expressed at the 10^-5 risk level). For UCMR 3, cancer-based HRLs were expressed 

at the 10^-5 level. EPA did evaluate both the purge and trap and micro-extraction methods listed by 

the State of California and felt that at this time, sufficient data could be determined using Method 

524.3 without requiring PWSs to incur the cost of the additional sampling and laboratory analysis 

associated with the California method.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)
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January 2012

32020 Other Methods - VOCs Page 144 of 401

Letter ID: 0080

Comment ID: 32080

Comment Code: 32020

Comment: An alternative method for 1,2,3-TCP developed by California Department of Health 

Services (now known as the California Department of Public Health) based on EPA Method 524.2 

is already in widespread use and capable of meeting an MRL of 0.005 ug/L level. EPA should 

consider including this method to achieve a lower MRL that is more consistent with the analyte’s 

HRL.[FN12: 2002, California Department of Health Services, Determination of 1,2,3-

Trichloropropane in Drinking Water by Purge and Trap Gas Chromatography/Mass Spectrometry, (

http://www.cdph.ca.gov/certlic/drinkingwater/Documents/Drinkingwaterlabs/TCPbyPT -

GCMS.pdf)]

Response: Please see response to Comment ID 31758 under comment code 32020 Other Methods 

- VOCs.
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January 2012

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Comment Code: 32100 1,2,3-Trichloropropane

Individual Comments

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31758

Comment Code: 32100

Other EPA Comment Codes and Descriptions: 32020 Other Methods - VOCs

Comment: 21. The purpose of UCMR monitoring is to establish occurrence at levels relevant to the 

HRL. Given the low HRL (0.005 ug/L) for 1,2,3-TCP and the availability since 2002 of a method 

(California purge and trap method) capable of measuring at or below the HRL, EPA should 

consider using this method (MRL of ~ 0.005 ug/L - See the table below) in lieu of 524.3 (MRL of 

0.03 ug/L) for 1,2,3-TCP. In UCMR1, EPA had all utilities analyze for nitrobenzene by method 

524.2 (MRL of 8 ug/L) under list 1 and a subset use method 526 (MRL of 0.5 ug/L) under list 2 due 

to the low HRL. There is thus a precedent for this recommendation. If not, EPA may be faced with 

estimating occurrence at relevant levels (e.g. <0.03 ug/L), with significant cost implications for 

utilities.

Listed below are MDL determinations over 9 day periods for two individual analysts for the 

California method, with spiking at the HRL level of 0.005 ug/L. This demonstrates that the cited 

method is reliable and sufficiently sensitive to be used for this analyte. There are currently numerous 

labs certified for this method for compliance monitoring in California. 

[Table: see PDF docket ID EPA-HQ-OW-2009-0090-0047]

Thank you for your consideration of our comments. If you have any questions or require 

clarification of the comments please do not hesitate to contact the undersigned. 

Sincerely yours, Andrew Eaton, PhD Technical Director/Vice President

Response: There are a number of health-based values currently listed in IRIS for 1,2,3-

trichloropropane. These range from non-cancer impacts of 28 μg/L to 42 μg/L, and for 10^-5 

cancer end points ranging from 0.01 μg/L to 0.05 μg/L. For CCL 3, cancer-based HRLs were 

calculated at the 10^-6 risk level; thus the HRL of 0.005 μg/L (it corresponds to the value of 0.05 

μg/L which is expressed at the 10^-5 risk level). For UCMR 3, cancer-based HRLs were expressed 

at the 10^-5 level. EPA did evaluate both the purge and trap and micro-extraction methods listed by 

the State of California and felt that at this time, sufficient data could be determined using Method 

524.3 without requiring PWSs to incur the cost of the additional sampling and laboratory analysis 

associated with the California method.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP
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Letter ID: 0067

Comment ID: 31898

Comment Code: 32100

Comment: Comments on Selected Contaminants on the Proposed UCMR3 List: 

1,2,3-Trichloropropane - NJDEP supports the inclusion of 1,2,3-trichloropropane (1,2,3-TCP) in 

the UCMR3. In detailed comments on the proposed USEPA Contaminant Candidate List 3 

submitted on May 21, 2008 (NJDEP, 2008a), NJDEP urged USEPA to address the regulation of 

1,2,3-TCP in drinking water. It is a potent genotoxic carcinogen, and it has been found at levels 

resulting in elevated cancer risk in some public water supplies and private wells in NJ and other 

states.

The NJDEP agrees with the MRL of 0.03 μg/L in the proposed UCMR3. New Jersey developed a 

drinking water guidance of 0.03 μg/L for 1,2,3-TCP to provide advice to public water supplies and 

private well owners and also has promulgated a groundwater standard of 0.03 μg/L based on a 

practical quantitation limit (PQL) of 0.03 μg/L, identical to the MRL proposed in the UCMR3. 

Additionally, the NJ Drinking Water Quality Institute recommended a New Jersey Maximum 

Contaminant Level of 0.03 μg/L, based on the same PQL (NJ DWQI, 2009a, b). The New Jersey

Drinking Water Quality Institute (NJDWQI, 2009) and USEPA IRIS (USEPA, 2009) have recently 

completed cancer risk assessments of this compound. According to both the NJ DWQI and the 

USEPA IRIS assessments, the health-based criterion for 1,2,3-TCP, based on 1 x 10-6 lifetime 

cancer risk, is below the PQL of 0.03 μg/L (NJ DWQI, 2009c).

Response: EPA appreciates your support and has included 1,2,3-trichloropropane on the UCMR 3 

Assessment Monitoring list.
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January 2012

32200 1,3-Butadiene Page 147 of 401

Comment Code: 32200 1,3-Butadiene

Individual Comments

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31617

Comment Code: 32200

Comment: To make room for Chromium-6, CTDPH suggests removing one of the following 

contaminants: 

1) 1,3-butadiene: this contaminant to some extent is superfluous, produced from combustion, is 

generally of concern in the outdoor and indoor atmosphere, and should present no threat to public 

drinking water supplies, especially groundwater sources. 

Response: EPA believes that monitoring for 1,3-butadiene is justified. The Chemical Update 

System states that more than one billion pounds of 1,3-butadiene were produced in 1998 and 2002. 

The Toxics Release Inventory indicates that almost two million pounds were released into the 

environment of 36 states. In addition, EPA has listed 1,3-butidiene as a B2, probable human 

carcinogen. Chromium-6 (hexavalent chromium) and total chromium have been added to the list of 

contaminants to be monitored. In addition, sec-butylbenzene and n-propylbenzene have been 

removed from the list of contaminants to be monitored. Please see response to comment ID 32067 

and comment code 38100 Chromium-6.

Commenter Name: Elizabeth Moran

Commenter Organization: American Chemistry Council

Letter ID: 0068

Comment ID: 31679

Comment Code: 32200

Comment: Submitted via resulations.sov Water Docket U.S. Environmental Protection Agency

Mail Code 282211T 1200 Pennsylvania Avenue, NW Washington, DC 20460 

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

Systems, 76 Fed. Reg. 11,713 (Mar. 3, 2011), Docket ID No. EPA-HQ- OW-2009- 0090

Dear Sir or Madam:

The Olefins Panel (Panel) of the American Chemistry Council submits these comments on the U.S. 

Environmental Protection Agency's (EPA) proposed Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR 3) for Public Water Systems. 76 Fed. Reg. 11,713 (Mar. 3, 2011). 

The Panel, which consists of companies [FN1:Panel member companies include Chevron Phillips 
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32200 1,3-Butadiene Page 148 of 401

Chemical Company, LP, The Dow Chemical Company, Eastman Chemical Company, Equistar 

Chemicals LP, ExxonMobil Chemical Company, NOVA Chemicals Inc., Shell Chemical LP, and 

TPC Group, Inc.] that manufacture, use, or process 1,3-butadiene, one of the substances included in 

the proposed UCMR 3, has a strong interest in the regulation and the approach that EPA utilized to 

develop it. 

The Panel urges EPA not to include 1,3-butadiene in the final UCMR 3 because 1,3-butadiene is a 

highly volatile gas that is expected to partition predominantly to air and is not expected to be present 

in drinking water. Therefore, requiring public water systems to monitor for 1,3-butadiene in drinking 

water is an unnecessary expense and is unlikely to present a meaningful opportunity for reducing 

public health risks. 

Pursuant to Section 1445(a)(2) of the Safe Drinking Water Act (SDWA), 42 U.S.C. § 300j- 4(a)(2), 

EPA is required to promulgate regulations every five years "establishing the criteria for a monitoring 

program for unregulated contaminants." Section 1401(6) of the SDWA defines "contaminant" as 

"any physical, chemical, biological, or radiological substance or matter in water." 42 U.S.C. § 300f(6) 

(emphasis added). Since 1,3-butadiene is not expected to be found in water, EPA should not include 

1,3-butadiene in the UCMR. 

EPA included 1,3-butadiene on the third Contaminant Candidate List (CCL 3) due to 1,3- 

butadiene's "potential to occur in drinking water" based on the total 2004 reported releases to the 

environment pursuant to the Toxics Release Inventory (TRI) program and the number of states in 

2004 having those TRI- reported releases. Notice, Drinking Water Contaminant Candidate List 3 - 

Draft, 73 Fed. Reg. 9628, 9637, 9640 (Feb. 21, 2008 ). Because, however, 1,3-butadiene is a highly 

volatile gas and, thus, is expected to partition predominantly to the atmosphere, the Panel urged 

EPA instead to consider the minimal level of surface water releases in determining whether 1,3-

butadiene should be included. See Comments of the Olefins Panel of the American Chemistry 

Council on Drinking Water Contaminant Candidate List 3-Draft (Docket No. EPA-HQ-OW-2007-

1189 -0089) (May 14, 2008) (Comments on CCL 3). A copy of the Olefins Panel's comments on the 

CCL 3 are enclosed for your information and incorporated by reference. 

In its response to comments, on the CCL 3, EPA stated that 

EPA believes that it is appropriate to use total environmental release data rather than the total 

quantity released to surface water to evaluate the potential of a contaminant to occur in drinking 

water, as the use of total environmental release data accounts for any releases to groundwater and 

for the propensity of a compound to migrate within the environment; whereas the use of only 

surface water release data would not take into account the release of a contaminant to groundwater 

or the migration or mobility of a compound. Discussion in the National Drinking Water Advisory 

Council (NDWAC) 2004 report supports this: "In surface waters, which are exposed to the air, 

compounds that volatilize will not be persistent, simply because they evaporate into the air and are 

not found in the water. However, in ground water, the same compounds may be persistent because 

they cannot evaporate. TCE, a common solvent, is a good example."

U.S. EPA, Final Comment Response Document for the Third Drinking Water Contaminant 

Candidate List (Categorized Public Comments) (Docket No. EPA-HQ- OW-2007-1189 -0188) 

(Aug. 2009), at 80.
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However, it is inappropriate to compare 1,3-butadiene to TCE since the two substances have 

significantly different physical and chemical properties. 1,3- Butadiene is a highly volatile gas that is 

expected to partition predominantly to air, while TCE is a liquid with a lower vapor pressure and 

higher solubility.[FN2: At 25°C, TCE has a vapor pressure of 74 mm Hg and a solubility of 1.366 

g/L. Agency for Toxic Substances and Disease Registry (ATSDR), Toxicological Profile for 

Trichloroethylene (Sept. 1997), at 184, available at http://www.atsdr.cdc.gov/ToxProfiles/tp19.pdf] 

As EPA's IRIS assessment of the chemical states, 1,3-butadiene "is very slightly soluble in water" 

and "a highly volatile gas [that] is expected to partition predominantly to the atmosphere and then 

undergo rapid destruction by photoinitiated reactions" [FN3:1,3-Butadiene's behavior in the 

environment is largely explained by its vapor pressure , which has been reported as 856 mm Hg 

(1141 hPa) at -1.5°C and 2110 mm Hg (2813 hPa) at 25°C. Although 1, 3-butadiene's water 

solubility has been reported as 735 mg/L at 25°C, suggesting that it has a degree of solubility, its 

Henry's Law constant (HLC) a measure of a chemical's volatilization rate from water shows that 13- 

butadiene will preferentially partition to air from solution. The HLC for 1,3- butadiene is calculated 

as 20,699 Pa-m3/mole using the water solubility and vapor pressure data for 25°C. See Comments 

on CCL 3 for a more detailed discussion.] U.S. EPA, Health Assessment of 1,3- Butadiene (Oct. 

2002) (IRIS Assessment), at 2-1, available at http://oaspub.epa.,ov/eims/eimscomm.getfile?p

download id=36309 ; see also ATSDR, Draft Toxicological Profile for 1,3- Butadiene (Sept. 2009) 

(Draft ATSDR Profile), at 89, available at http://www.atsdr.cdc.gov/toxprofiles/tp28.pdf. 

Moreover, "[b]ased on its physical properties, rapid volatilization of 1,3-butadiene from either soil or 

water to [the] atmosphere is expected to dominate over all other potential environmental processes." 

IRIS Assessment at 2-1; Draft ATSDR Profile at 89. As EPA recognizes, "1,3-butadiene is not 

persistent in the environment." U.S. EPA, Possible Contaminants for Inclusion on UCMR 3 -

Information Compendium (Docket No. EPA-HQ-OW-2009- 0090-0033) (Dec. 2010) (Information 

Compendium), at 30. In sum, quantities of 1,3-butadiene that are released to air, which are the vast

majority of the total environmental releases, do not end up in drinking water, and any quantities that 

are released to other media partition to the atmosphere.[FN4:For example, according to the TRI 

Explorer Chemical Report for 2004, of the total quantity of 1,3 -butadiene released to the 

environment, more than 96 percent was in the form of fugitive and point source air emissions. See

TRI Explorer Chemical Report for 2004, available at http://www.epa.gov/triexplorer/.] 

According to EPA's information sheet on 1,3-butadiene, in 2004, the total quantity of 1,3- butadiene 

released to surface water was 493 pounds encompassing eight states. See Information Compendium, 

at 29. By 2006, this figure had decreased to to 113 pounds in seven states. See id at 30. This level of 

surface water release is quite minimal, and as noted above, any 1,3-butadiene so released rapidly 

volatilizes to the atmosphere.[FN5: Any 1,3-butadiene that somehow finds its way into groundwater, 

which, given the chemical 's volatility and sparing solubility in water, is likely to be an exceedingly 

small amount, would volatilize quickly or otherwise be removed during the drinking water treatment 

process.]

In order to preserve the limited resources available to public water systems, EPA should not require 

monitoring of chemicals, like 1,3-butadiene, which have little or no potential to occur in drinking 

water. Therefore, EPA should not include 1,3-butadiene in the UCMR. 

If you would like to discuss any of the comments in more detail, please contact me at 301 924 2006 

or Elizabeth_Moran@americanchemistry.com. Thank you in advance for your consideration of 

these comments.
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32200 1,3-Butadiene Page 150 of 401

Yours truly, 

Elizabeth J. Moran, Ph.D. Manager, Olefins Panel

Enclosure [See PDF Docket ID: EPA-HQ-OW-2009-0090-0068.1]

Response: Please see response to Comment ID 32067 under comment code 32000 Volatile 

Organic Compounds (VOCs). 
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January 2012

32400 1,1-Dichloroethane Page 151 of 401

Comment Code: 32400 1,1-Dichloroethane

Individual Comments

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31899

Comment Code: 32400

Comment: 1,1-Dichloroethane - NJDEP supports the inclusion of 1,1-dichloroethane (1,1- DCA) 

in the UCMR3 to determine its national occurrence. Because of its occurrence in NJ public water 

supplies and its potential health effects, NJ adopted an MCL of 50 μg/L for 1,1-DCA in 1996, based 

on recommendations from the New Jersey Drinking Water Quality Institute (NJ DWQI, 1994a,b). 

The MRL of 0.03 μg/L proposed in the UCMR3 is well below the health-based level for 1,1- 

dichloroethane and the New Jersey PQL of 1 μg/L.

Response: EPA appreciates your support and has included 1,1-dichloroethane on the UCMR 3 

Assessment Monitoring list.
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January 2012

32800 Chlorodifluoromethane (HCFC-22) Page 152 of 401

Comment Code: 32800 Chlorodifluoromethane (HCFC-22)

Individual Comments

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31618

Comment Code: 32800

Comment: To make room for Chromium-6, CTDPH suggests removing one of the following 

contaminants: 

2) chlorodifluoromethane (HCFC-22): this contaminant is not very toxic and very unlikely that it 

wonld be prevalent in public water supply systems to merit its monitoring. 

Response: EPA believes that monitoring for chlorodifluoromethane is justified. The 2006 Toxics 

Release Inventory indicates that almost 3,000 pounds of chlorodifluoromethane were released into 

surface water across two states and that more than seven million pounds were released into the 

environment across 35 states. In addition, with a water solubility of 2,770 mg/L and a 

biodegradation half life of 15 days, it is very mobile and moderately persistent in water (76 FR 

11713). Chromium-6 (hexavalent chromium) and total chromium have been added to the list of 

contaminants to be monitored. In addition, sec-butylbenzene and n-propylbenzene have been 

removed from the list of contaminants to be monitored. Please see response to comment ID 32067 

and comment code 38100 Chromium-6.

Commenter Name: James L. Hoover 

Commenter Organization: DuPont Fluropolymer Solutions (FPS) 

Letter ID: 0095

Comment ID: 31789

Comment Code: 32800

Comment: DuPont Chemicals & Fluoroproducts P .O. Box 80702 Wilmington, DE 19805 To: 

Water Docket, United States Environmental Protection Agency (EPA) Mail Code 282211 T 1200 

Pennsylvania Avenue, NW. Washington, DC 20460 Attention : Docket ID No. OW-2009-0090

April 27, 2011 RE: Comments on "Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR3) for Public Water Systems"

 To Whom It May Concern: 

E.I. du Pont de Nemours and Company (DuPont) respectfully submits to the Environmental 

Protection Agency (EPA) comments and information in response to a Federal Register Notice

issued on March 3, 2011, "Revisions to The Unregulated Contaminant Monitoring Regulation 

(UCMR3) for Public Water Systems" (Docket No. OW-2009-0090; FRL-9274-2).
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32800 Chlorodifluoromethane (HCFC-22) Page 153 of 401

DuPont has a 208-year legacy of core values, rooted strongly in safety, health and environmental 

stewardship. DuPont is a science company with a history of innovation. This innovation includes 

experience and expertise in putting science to work to design in product attributes that help protect 

or enhance human health, safety and the environment. DuPont supports the objectives of the 

"Unregulated Contaminant Monitoring Regulation (UCMR3) for Public Water Systems" program.

The subject of our comments is the chemical HPFC-22 (CAS #75-45-6; EINECS #200- 871-9; 

IUPAC name; chlorodifluoromethane), which is included in "Table 1 - UCMR Contaminant List" 

under "List 1 Assessment Monitoring - Chemical Contaminants". DuPont believes that HCFC-22 

should not be included in the Agency's final "Table 1 - UCMR Contaminant List" based on the 

following: 

1. There is a very low potential for exposure to HCFC-22 in drinking water because any HCFC-22 

gas initially dissolved in liquid water will transport rapidly out of the water into the atmosphere. This 

mobility from water into the atmosphere stems from the physical attributes of HCFC-22 which is a 

very volatile gas at ambient temperature. Specifically, HCFC-22 has a very low boiling point of 

[minus] -40.8C), has modest solubility in water (2.93 g/l at 25 C), has a high Henry's law constant 

(3,025 Pam3/ mole at 25C) and a high vapor pressure (1,045 kPa at 25 C). All of these physical 

characteristics will facilitate the rapid transport of any HCFC-22 out of liquid water and into the 

atmosphere through evaporation. 

2. From the measured concentration of gaseous HCFC-22 in the atmosphere of approximately 175 

parts per trillion (ppt) and the Henry's law constant (3,025 Pam3/ mole at 25C), a calculated 

maximum equilibrium concentration of HCFC-22 in liquid water would be less than 1 part per 

trillion (ppt).

As described above, due to the measured physical properties of HCFC-22, it is scientifically very 

unlikely that the compound could remain in drinking water as it will rapidly partition from liquid 

water into the atmosphere, even if the initial vehicle for release was a water-based solution. Hence, 

there is a very low potential for exposure via drinking water; and a very low probability of 

analytically detecting it in drinking water. DuPont therefore believes that HCFC-22 should not be 

included in the "Table 1 - UCMR Contaminant List" of the currently proposed UCMR3 program. 

Thank you for the opportunity to comment on this very important matter. If you have any questions 

or would like additional information, please call our office at 302-999- 2147.

Sincerely,

James R. Hoover Global Regulatory Affairs Manager DuPont Fluoropolymer Solutions (FPS) 

Response: Please see response to Comment ID 32067 under comment code 32000 Volatile 

Organic Compounds (VOCs). 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

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33010 EPA Method 522 - 1,4-Dioxane Page 154 of 401

Comment Code: 33010 EPA Method 522 - 1,4-Dioxane

Individual Comments

Commenter Name: Dennis O'Sullivan

Commenter Organization: DoD Safe Drinking Water Act Services Steering Committee

Letter ID: 0048

Comment ID: 31610

Comment Code: 33010

Comment: [1] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522: 6; 15 

Para#/ Line# (Methods documents): METHOD 522: 4.6; 9.2.1 Comment Classification C/M/S/A: 

S 

Comment: Recommendations need to be a requirement. 

Rationale: This should be a requirement (must), not a recommendation (should). This lends itself to 

the extraction of samples using media that has not been tested and may result in the need to 

recollect samples due to a laboratory error that could have been avoided. It should be noted that 

Section 9.2.1 requires new lot or brand of SPE materials or solvents be tested before use. 

[2] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:10 Para#/ Line# 

(Methods documents): METHOD 522: 6.10.4 Comment Classification C/M/S/A: S 

Comment: Recommendations need to be a requirement. 

Rationale: It is recommended that the minimum number of scans (5) be defined as a requirement, 

instead of a suggested minimum. 

[3] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:14 Para#/ Line# 

(Methods documents): METHOD 522: 8.3 Comment Classification C/M/S/A: S 

Comment: Temperature and hold time requirements vary without explanation. 

Rationale: Why are the shipping and laboratory storage temperature requirements different? Samples 

are to be shipped at less than or equal to 10°C, but yet the laboratory must store the samples once 

received at less than or equal to 6°C.

[4] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:14; 26 Para#/ Line# 

(Methods documents): METHOD 522: 8.3.1; 11.3.1 Comment Classification C/M/S/A: S 

Comment: Actions resulting from failing dechlorination test are not defined. 

Rationale: This section requires the analyst to verify the sample has been dechlorinated upon receipt 

or just prior to extraction, but does not indicate what the laboratory must do if the sample has not 

been dechlorinated. 
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[5] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:26 Para#/ Line# 

(Methods documents): METHOD 522: 11.3.2 Comment Classification C/M/S/A: S 

Comment: Actions resulting from failing pH test are not defined. 

Rationale: This section states the pH of the sample must be verified to be less than 4, however, it 

does not provide the laboratory with information on what to do if the sample pH is greater than 4. 

[6] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:17 Para#/ Line# 

(Methods documents): METHOD 522: 9.3.1 Comment Classification C/M/S/A: S 

Comment: Non-detects in samples are not considered separately.

Rationale: This section states that regardless of whether detected or not in a sample, the results will 

be invalidated if the LRB fails to meet acceptance criteria. It is recommended that an exception be 

made for samples in which the analyte was not detected.

[7] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:18; 19; 20; 24 Para#/ 

Line# (Methods documents): METHOD 522: 9.3.3; 9.3.7; 9.3.8; 10.2.4 Comment Classification 

C/M/S/A: S 

Comment: Sliding scale of acceptance criteria over the quantitation range introduces additional 

uncertainty to the analysis.

Rationale: Since the low-level LFB concentration is within the quantitation range (1 - 2 times MRL), 

it is not justified to have varying acceptance criteria within the quantitation range. It cannot be 

determined at what point the uncertainty changes from 50 to 30%. It is recommended that the same 

acceptance criteria be used for each LFB, regardless of the concentration. This same comment 

applies to the evaluation of RPDs of the field duplicates and LFSM and LFSMDs (Section 9.3.8.4), 

CCC recoveries (Section 10.3.3), and CAL standards (10.2.4)..

[8] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:18; 27; 29 Para#/ 

Line# (Methods documents): METHOD 522: 9.3.5.2; 11.4.4; 11.5.4 Comment Classification 

C/M/S/A: S 

Comment: Internal standard addition process is prohibiting and included as part of the extraction 

process.

Rationale: It is recommended that the internal standard be added just prior to analysis to an aliquot 

of the final extract volume. The final volume of the 500mL and 100 mL samples are 10 mL and 2 

mL, respectively. By spiking only a portion of the final extract, the laboratory will have the ability to 

correct for any internal standard spiking errors without reextraction or collection of more sample 

(See Section 9.3.5.2).

[9] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:17 Para#/ Line# 

(Methods documents): METHOD 522: 9.3.5.2 Comment Classification C/M/S/A: S
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Comment: Unclear which standard is being referenced.

Rationale: Does this mean the last CCC standard or last CAL standard analyzed in the calibration 

curve? It is recommended the last CCC standard analyzed be used since it would the most recent 

standard analyzed.

[10] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522:20 Para#/ Line# 

(Methods documents): METHOD 522: 9.3.7.2 Comment Classification C/M/S/A: S

Comment: Concentrations less than the MRL are used to correct the LFSM and LFSMD are

qualitative and not reported in the native samples. 

Rationale: Values below the MRL are qualitative and may not be accurate enough for data reporting. 

As a result, only concentrations greater than the MRL are reported in native samples. It is 

recommended that LFSM and LFSMD values only be adjusted using values reported in the native 

samples (between the MRL and highest calibration standard). 

[11] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522: 24 Para#/ Line# 

(Methods documents): METHOD 522: 10.2.3 Comment Classification C/M/S/A: S 

Comment: The acceptance criteria calibration curve is not provided.

Rationale: The criteria (e.g., %RSD, correlation coefficient) used for evaluating the calibration curve 

that is generated by the calibration standards is not defined by the method. It is recommended 

criteria for the curve be included along with the requirements for each calibration standard. 

[12] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522: 29 Para#/ Line# 

(Methods documents): METHOD 522: 12.1 Comment Classification C/M/S/A: S 

Comment: Recommendations need to be a requirement. 

Rationale: The recommendation that the retention time should be within one to two seconds of the 

retention time of the last CCC should be made a requirement. Currently, the method has no 

requirement for retention time. 

[13] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 522: 30 Para#/ Line# 

(Methods documents): METHOD 522: 12.2 Comment Classification C/M/S/A: S 

Comment: No corrective actions provided 

Rationale: The method does not provide any guidance on whether the quantified result is reported 

and flagged or not reported when the ion ratio fails to meet criteria.

Response: [1] Section 4.6 of Method 522 provides a global cautionary statement regarding 

interferences from solid phase extraction (SPE) materials. As the commenter has noted, Section 

9.2.1 spells out the requirements for evaluating new lots and brands of SPE materials through the 
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33010 EPA Method 522 - 1,4-Dioxane Page 157 of 401

use of laboratory reagent blanks. The requirements described in Section 9.2.1 are sufficient to 

prevent laboratory errors due to SPE interferences.

[2] Section 6.10.4 of Method 522 is a general statement of the equipment required for use in the 

method. Sections 10.2.1 and 10.2.2, which describe specific instrument tuning and sample analysis 

requirements both state that a minimum of 5 scans must be acquired by the mass spectrometer 

during chromatographic peak elution. 

[3] While it would be optimal to store samples at 6 deg. C from collection to analysis, it is 

impractical. Maintaining 6 deg. C during transport from the sampling location to the laboratory is 

extremely difficult.

Most commercially available frozen gel packs will not maintain 6 deg. C.

However, they can maintain the required 10 deg. C. Therefore, when sample holding times are 

developed during methods development, the samples are maintained at 10 deg. C for 48 hours and 

then the temperature is reduced to 6 deg. C for the remainder of the holding time testing to more 

accurately represent actual shipping and storage conditions. 

[4] The word "verify" in Method 522 regarding sample dechlorination implies that the analyst should 

not proceed with the method if verification cannot be made. EPA will specifically clarify in the 

UCMR 3 Laboratory Approval Requirements and Information Document that samples that arrive at 

the laboratory that have not been dechlorinated will be discarded and resampled. 

[5] The word "verify" in Method 522 regarding sample acidification with sodium bisulfite implies 

that the analyst should not proceed with the method if verification cannot be made. EPA will 

specifically clarify in the UCMR 3 Lab Approval Manual that samples that arrive at the laboratory 

that have not been acidified will be discarded and resampled. 

[6] While the commenter raises an interesting point, EPA believes that the laboratory reagent blank 

(LRB) represents a fundamental quality control element that must be met. Since the only source of 

contamination of an LRB is within the laboratory itself or the reagents that it uses, then 

contamination of an LRB indicates the potential for contamination of a field sample. Therefore, the 

source of the contamination must be corrected before analyzing further samples. 

[7] These acceptance criteria meet EPA's data quality objectives. Method 522 and many other EPA 

methods for drinking water monitoring that employ these same acceptance criteria have been 

through an extensive peer review process. EPA has defined the Minimum Reporting Limit (MRL) 

for all UCMR 3 analytes and methods as the concentration that can be reliably measured within 50 - 

150 % of the true value. The precision and accuracy of chemical analysis is a function of the 

concentration being measured, therefore, it is valid to specify data quality objectives that take this 

fact into account and change the data quality requirements to a level consistent with the 

performance of each method for concentrations exceeding the MRL. 

[8] Addition of the Internal Standard immediately post extraction is an important quality control 

step for this method. The extract is in dichloromethane which is extremely volatile. A change in the 

extract volume through evaporation during extract storage has the potential to affect the accuracy of 

the final measurement. Adding the Internal Standard immediately post extraction ensures that any 

volume changes during storage will be corrected in the Internal Standard quantitation process. 
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Addition of the Internal Standard into an extract is a routine task and not prone to frequent errors 

requiring reextraction. 

[9] The "most recently acceptable calibration standard" could be either a CCC or the last CAL 

standard analyzed for the curve. The only criterion is that it be the most recent. The language in this 

section is standard for EPA drinking water compliance methods. EPA believes the terminology in 

this section is adequate. A CCC is defined at the beginning of the method as "A calibration standard 

that is analyzed periodically to verify the accuracy of the existing calibration." Therefore, the last 

CCC or CAL standard are both acceptable. 

[10] Meaningful LFSM data at or near the MRL can only be obtained if native amounts are 

subtracted. A LFSM fortified at the MRL in a sample where the native amount is just below the 

MRL will lead to the false conclusion that there is a matrix bias unless the native amount is 

subtracted. The Minimum Reporting Limit (MRL) is simply the lowest concentration that can be 

reported in a field sample. The quality control aspects, both qualitative and quantitative, are based 

upon the MRL. Calibration standards are run down to the MRL, reagent blanks are evaluated 

relative to the MRL. However, statistical evaluations of data quality, such as the LFSM and LFSMD, 

would be biased if values below the MRL were not incorporated. 

[11] Acceptance criteria for the calibration curve are in Section 10.2.4 for correlation coefficients are 

poor indications of the quality of the calibration curve. In both cases, these measures minimize what 

may be significant errors at low concentrations. Methods used for the analysis of drinking water, 

where accurate low concentration calibration is essential, use the procedure detailed in section 10.2.3 

which requires each calibration standard to be compared back to the calibration curve and must be 

within 30% of their true value. This is a far better method of assuring the quality of the calibration 

curve.

[12] EPA has adopted a policy of flexibility with regard to chromatographic conditions in drinking 

water analytical methods. Therefore, it would be inappropriate to set fixed retention time criteria 

windows. Method 522 provides guidance to the analyst for establishing acceptance criteria for 

retention times. This guidance recommends that three times the standard deviation of the retention 

time be used to establish an appropriate retention time window. This guidance is compatible with 

the use of flexible chromatographic conditions. 

[13] Ion ratios must meet the identification criteria described in the method. If the ions ratios are not 

met, the identification cannot be made and the analyte is reported as a non-detect.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31900

Comment Code: 33010

Other EPA Comment Codes and Descriptions: 33100 1,4-dioxane 

Comment: 1,4-Dioxane - NJDEP supports the inclusion of 1,4-dioxane in the UCMR3. As is the 

case in other states, 1,4-dioxane has been detected in groundwater in New Jersey. New Jersey has 

developed an Interim Ground Water Quality Standard of 10 μg/L for 1,4-dioxane based on a PQL 
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33010 EPA Method 522 - 1,4-Dioxane Page 159 of 401

of 10 μg/L (NJDEP, 2008b). This is higher than the health-based criterion of 3 μg/L, which is 

based on a 1 x 10-6 lifetime cancer risk.

NJDEP supports the recommendation of Method 522, with an MRL of 0.07 μg/L, in the proposed 

UCMR3. Method 522 is newer and more sensitive than the older method used as the basis for the 

current New Jersey Interim Ground Water Quality Criterion, and is able to quantify to 

concentrations below levels of human health concern. 

Response: EPA appreciates your support and has included 1,4-dioxane on the UCMR 3 

Assessment Monitoring list.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32076

Comment Code: 33010

Comment: 2. EPA Method 522 was not subjected to rigorous testing at the proposed MRL level. 

Anecdotal evidence is that 1,4-dioxane could be widespread at the proposed MRL, raising concerns 

about reliability of sampling protocols. 

Response: The performance of EPA Method 522 at the MRL was demonstrated by three 

laboratories prior to completion. The method was also peer reviewed by experts with experience in 

the analysis of 1,4-dioxane. While 1,4-dioxane is volatile enough to potentially become airborne, it is 

primarily used as a stabilizer for chlorinated solvents and is a manufacturing by-product in the 

manufacture of a number of personal care products. Since these solvents are not typically used in a 

drinking water utility, it is highly unlikely that contamination of drinking water samples during 

collection and shipping would occur. Some examples are hormones and PFCs which have the 

potential to be introduced into samples from the sampler's skin or clothing. Aromatic compounds 

like benzene and toluene can be introduced from truck exhaust or other fuel exhaust. Common 

laboratory contaminants such as dichloromethane or phthalates can be introduced into samples 

through the use of contaminated bottles or liquid preservatives. 1,4-Dioxane does not fall into any 

of these common categories of contaminants. It is a specialty chemical used in the manufacture of 

other chemicals. Historically it has been used to stabilize chlorinated solvents, but that use has 

declined in recent years with the deceased use of trichloroethane. EPA has not been able to locate 

any documentation of field contamination of field blanks during sampling for 1,4-dioxane. EPA 

disagrees that the current sampling protocol for 1,4-dioxane is unreliable. 
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33100 1,4-Dioxane Page 160 of 401

Comment Code: 33100 1,4-Dioxane

Individual Comments

Commenter Name: Roger Sokol 

Commenter Organization: NY State Dept. of Health

Letter ID: 0065

Comment ID: 31677

Comment Code: 33100

Comment: In addition, the BWSP supports the inclusion of 1,4-dioxane to the UCMR3 

contaminant list. This chemical is a persistent contaminant in private drinking water wells in NYS 

and it is not effectively removed from well water with the granular activated carbon filtration 

systems. Due to the potential for 1,4- dioxane to contaminate groundwater and surface water, the 

toxicological properties and the difficulties related to treatment, the BWSP supports collecting 

occurrence data on this chemical through the UCMR3. 

Response: EPA appreciates your support and has included 1,4-dioxane on the UCMR 3 

Assessment Monitoring list.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31747

Comment Code: 33100

Comment: 10. For 1,4-dioxane, with an MRL of 0.07 ug/L that is almost 50 times lower than the 

HRL, and generally only attainable by SIM, we are again concerned about the potential for false 

positives. In reviewing our own 1,4-dioxane database, we found that even though we have used a lab 

reporting limit of 0.5 ug/L, we have seen a large number of hits that are significantly below this level 

(many below the calculated MDL but still generate a GCMS signal). These could either be real hits 

or represent false positives due to lab or field issues. It is again appropriate to consider requiring a 

field blank and providing guidance for sample processing with a field blank. 

Response: The performance of EPA Method 522 at the MRL was demonstrated by three 

laboratories prior to completion. The method was also peer reviewed by experts with experience in 

the analysis of 1,4-dioxane. While 1,4-dioxane is volatile enough to potentially become airborne, it is 

primarily used as a stabilizer for chlorinated solvents and is a manufacturing by-product in the 

manufacture of a number of personal care products. Since these solvents are not typically used in a 

drinking water utility, it is highly unlikely that contamination of drinking water samples during 

collection and shipping would occur. Some examples are hormones and PFCs which have the 

potential to be introduced into samples from the sampler's skin or clothing. Aromatic compounds 

like benzene and toluene can be introduced from truck exhaust or other fuel exhaust. Common 

laboratory contaminants such as dichloromethane or phthalates can be introduced into samples 

through the use of contaminated bottles or liquid preservatives. 1,4-Dioxane does not fall into any 
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33100 1,4-Dioxane Page 161 of 401

of these common categories of contaminants. It is a specialty chemical used in the manufacture of 

other chemicals. Historically it has been used to stabilize chlorinated solvents, but that use has 

declined in recent years with the deceased use of trichloroethane. EPA has not been able to locate 

any documentation of field contamination of field blanks during sampling for 1,4-dioxane. EPA 

disagrees that the current sampling protocol for 1,4-dioxane is unreliable. 

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31866

Comment Code: 33100

Comment: In addition, New York supports the inclusion of 1,4-dioxane on the UCMR3 

contaminant list. This chemical is a persistent contaminant in private drinking water wells in New 

York State and it is not effectively removed from well water with the granular activated carbon 

filtration systems. Due to the potential for 1,4-dioxane to contaminate groundwater and surface 

water, the toxicological properties and the difficulties related to treatment, the state supports 

collecting occurrence data on this chemical through the UCMR3. Even though EPA considers these 

of national interest and includes them in the UCMR, we encourage EPA to also work with the state 

to help them address these issues on a regional scale.

Response: EPA appreciates your support and has included 1,4-dioxane on the UCMR 3 

Assessment Monitoring list.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31900

Comment Code: 33100

Other EPA Comment Codes and Descriptions: 33010 EPA Method 522 - 1,4-dioxane 

Comment: 1,4-Dioxane - NJDEP supports the inclusion of 1,4-dioxane in the UCMR3. As is the 

case in other states, 1,4-dioxane has been detected in groundwater in New Jersey. New Jersey has 

developed an Interim Ground Water Quality Standard of 10 μg/L for 1,4-dioxane based on a PQL 

of 10 μg/L (NJDEP, 2008b). This is higher than the health-based criterion of 3 μg/L, which is 

based on a 1 x 10-6 lifetime cancer risk.

NJDEP supports the recommendation of Method 522, with an MRL of 0.07 μg/L, in the proposed 

UCMR3. Method 522 is newer and more sensitive than the older method used as the basis for the 

current New Jersey Interim Ground Water Quality Criterion, and is able to quantify to 

concentrations below levels of human health concern. 

Response: EPA appreciates your support and has included 1,4-dioxane on the UCMR 3 

Assessment Monitoring list.
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Comment Code: 34000 Metals

Individual Comments

Commenter Name: Roger Sokol 

Commenter Organization: NY State Dept. of Health

Letter ID: 0065

Comment ID: 31676

Comment Code: 34000

Other EPA Comment Codes and Descriptions: 32000 Volatile Organic Compounds (VOCs) 

Comment: Proposed list of contaminants 

The BWSP also supports inclusion of molybdenum, strontium, bromomethane and chloromethane 

on the UCMR3 contaminant list. All 4 of these contaminants are associated with hydrofracturing in 

the Marcellus Shale. Occurrence data on these contaminants will fill a data gap relative to this 

controversial process. 

Response: EPA appreciates your support and has included molybdenum, strontium, 

bromomethane, and chloromethane on the UCMR 3 Assessment Monitoring list. 

Commenter Name: Deborah H. Metz 

Commenter Organization: Greater Cincinnati Water Works (GCWW)

Letter ID: 0085

Comment ID: 31709

Comment Code: 34000

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: 4. Which metal could be dropped if hexavelent chromium monitoring is added 

a. We recommend dropping a metal with least known amount of human health effects data

Response: EPA believes that monitoring for the selected metals are justified. Cobalt is a 2b possible 

human carcinogen, molybdenum has a health risk level of 35 μg/L and vanadium has a health risk 

level of 21 μg/L. While strontium has a relatively high health risk level of 4,200 μg/L, it has 

previously been detected at high percentages (>90%) in a number of water occurrence studies, with 

upper levels of quantitation at concentrations far exceeding this health level (76 FR 11713). 

EPA selected sec-butylbenzene and n-propylbenzene, non-carcinogenic VOCs, for removal after 

considering data submitted by states that indicated very low occurrence rates. EPA also considered 

the fact that the currently available health reference levels, 10.3 μg/L and 5.83 μg/L, respectively, 

are well above the reported levels of occurrence in these data. Therefore, sec-butylbenzene and npropylbenzene have been removed from the list of contaminants to be monitored. Chromium-6 

(hexavalent chromium) and total chromium have been added to the list of contaminants to be 
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34000 Metals Page 163 of 401

monitored. Please see response to comment code 38100 Chromium-6.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31865

Comment Code: 34000

Other EPA Comment Codes and Descriptions: 32000 Volatile Organic Compounds (VOCs) 

Comment: * New York Recommendations: New York State specifically supports some listed 

contaminants that are a priority for them because of local occurrence or potential occurrence. New 

York supports inclusion of molybdenum, strontium, bromomethane and chloromethane on the 

UCMR3 contaminant list. All four of these contaminants are associated with hydrofracturing in the 

Marcellus Shale. Occurrence data on these contaminants will fill a data gap relative to this

controversial gas extraction process.

Response: EPA appreciates your support and has included molybdenum, strontium, 

bromomethane, and chloromethane on the UCMR 3 Assessment Monitoring list. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32068

Comment Code: 34000

Comment: [Table 1. Relevant Rationale for Removing Specific Contaminants from UCMR3 [See 

PDF Docket ID: EPA-HQ-OW-2009-0090-0080.1]] Metals / EPA 200.8, ASTM D5673-10, SM 

3125 / Strontium / Cost - Strontium commonly occurs at high levels relative to the proposed MRL 

of 0.3 ppb and will thus require dilution because of the low MRL. This leads in turn to costly reanalysis of samples. Also, the health reference level (HRL) is very high and available data suggests

that strontium will not likely occur at concentrations approaching the HRL.[FN1 - Raising the MRL 

for strontium would eliminate this rationale. Such a change is warranted because of the analyte’s 

extremely high HRL.]

Response: EPA agrees that strontium is easily measured with reporting concentrations below the 

currently available levels of health concern. Also, EPA agrees that there is a considerable quantity of 

data available on the occurrence of strontium in water. However, there has not been any recent 

nationwide occurrence survey of strontium in drinking water (the latest is the National Inorganics 

and Radionuclides Survey conducted in 1984 - 1986). Collection of more recent drinking water 

occurrence data will greatly help EPA determine if there is a need to regulate strontium in drinking 

water, and if so, at what concentration.
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Comment Code: 34010 EPA Method 200.8 Rev 5.4 - Metals

Summary Response to Comments on EPA Method 200.8 Rev 5.4 - Metals: Regarding 

comments on metal speciation, with the exception of inorganic mercury, EPA has historically 

monitored for total metals. While EPA agrees with the commenter that the health effects of 

different species of metals can vary greatly, EPA has historically based MCLs on the health effect of 

the most hazardous species while measuring the total in order to maximize public health protection.

Monitoring at both the entry point to the distribution system (EPTDS) and the distribution system 

maximum residence time (DSMRT) location will help EPA determine whether any vanadium is 

being leached into the drinking water in the distribution system.

Individual Comments

Commenter Name: Sandra Carey

Commenter Organization: International Molybdenum Association 

Letter ID: 0074

Comment ID: 31694

Comment Code: 34010

Comment: -It would be preferable to use the 200.8 (EPA-NERL) analytical method for

molybdenum because it can detect down to the 1 ppb level whereas the 200.7 method can only 

detect to 10 ppb. 

We thank you for this opportunity to submit our above comments, and remain at your disposal for 

further dialogue. 

Yours faithfully 

Sandra Carey

Sandra Carey HSE Executive

Kindly direct further correspondence to: sandracarey@imoa.info 

Attachments:

1) REACH Chemical Safety Report on Molybdenum (CAS No.7439-98-7/EINECS No. 231-107-2), 

authored by the REACH Molybdenum Consortium (an initiative of IMOA).

2) IMOA 2008 Submission to US-EPA re inclusion of molybdenum in CCL3 

3) February 2010 Critical Review of Kovalskiy et al study,1961, prepared by EBRC GmbH

[See PDF Docket ID: EPA-HQ-OW-2009-0090-0074.1]
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Response: EPA has identified Method 200.8, as proposed, and not Method 200.7 for the analysis of 

molybdenum in UCMR 3. 

Commenter Name: John W. III Hillbert 

Commenter Organization: Vanadium Producers and Reclaimers Association (VPRA) 

Letter ID: 0059

Comment ID: 31856

Comment Code: 34010

Comment: For these reasons, and to be consistent with the CCL3, VPRA is concerned with the 

lack of specificity under the proposed rule regarding what form of vanadium PWSs are to monitor. 

Specifically, for monitoring results to be relevant, VPRA is recommending that the EPA implement 

the following measures: 

* Specify Form of Vanadium: Consistent with EPA's decision to limit the listing of vanadium under 

the CCL3 to only "soluble forms of vanadium found in drinking water including a variety of 

vanadium ions from vanadium salts," [FN2: U.S. EPA, Final Comment Response Document for the 

Third Drinking Water Contaminant Candidate List 3 (Categorized Public Comments) (2009) at 224; 

Docket Identification EPA-HQ-OW-2007-1189 FLR-8963- 6 (see attached).] VPRA urges that EPA 

provide this same frame of reference to PWS operators in the final UCMR 3 rule, and ensure that 

the monitoring method used is sufficient for this purpose. 

* Require Minimum Speciation though Analytical Pre-Step: At a minimum, individual concentrations 

of the +4 and +5 oxidation states of vanadium should be distinguished and reported. None of the 

EPA's proposed methods for analysis via inductively coupled plasma-mass spectroscopy (ICP-MS) 

as described in EPA 200.8, ASTM D5673-10, or SM 3125 allow for vanadium species 

differentiation. Therefore, VPRA recommends that EPA develop guidelines for speciation of 

vanadium as a pre-step before ICP-MS analysis.

* Characterize Samples: There are key properties that are critical to characterize the collected water 

samples to allow a reasonable estimation of the equilibrium state of the dissolved vanadium with 

respect to oxidation state, protonation state and oligomeric content. These data are pH, reduction 

potential, ionic strength, dissolved oxygen levels, dissolved organic content, and dissolved 

concentrations of major anions (i. e .. ammonium, nitrate, phosphate, sulfate, and halides), major 

cations (i. e., calcium, magnesium, sodium, and potassium), and other metals expected to be in the 

water at relevant levels, including aluminum, iron, manganese, and zinc. PWSs should also note the 

quantities of any regional water additives such as fluoride and pipe corrosion inhibitors, that might 

affect vanadium speciation.

* Collect Unpreserved Sample to Address Potential for Change in Oxidation State: EPA's proposed 

sampling methods describe the preservation of the collected water samples by acidification; VPRA is 

recommending that a second, unpreserved sample be collected in recognition of the potential for 

acidification to change the oxidation state of the dissolved vanadium species. VPRA recommends 

that the sample sizes each exceed 200 milliliters (mL).

* Filter to Isolate Dissolved Metal Species: Steps must be taken to ensure that only the dissolved 

metal species are measured. Samples must be passed through 0.45-~Lm filters to remove any 
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34010 EPA Method 200.8 Rev 5.4 - Metals Page 166 of 401

sediment or particulate matter prior to preservation by acidification. Also, contamination of the 

collected samples by external trace metals should be prevented by the cleaning of all collection

equipment with nitric acid, deionized water and sufficient rinsing with portions of the water to be 

sampled. 

These considerations will permit the EPA to obtain a more complete understanding of vanadium's 

occurrence and its source in the drinking water supply that the Agency appears to be seeking with 

this proposal. 

II. The UCMR Program

The UCMR program originates from the Safe Drinking Water Act (SDWA), 42 U.S.C. [sec] 300f, 

which requires the EPA to establish a program for monitoring up to 30 unregulated contaminants 

every five years. Implementing regulations are found under 40 CFR Part 141. The goal of the 

UCMR program is to generate national occurrence data for those contaminants suspected to be 

present in drinking water and listed under the CCL in order to make future regulatory 

determinations under the SDW A. Consequently, in large part, EPA develops the UCMR list from 

the CCLs (EPA also can select other contaminants).

In this case, the EPA evaluated the final CCL3 list that included 104 chemicals or chemical groups 

and 12 microbiological contaminants.[FN3: See 74 Fed. Reg. 51,850 (October 8, 2009)] EPA then 

used additional sources of information about other emerging contaminants of potential concern, to 

establish an initial list of approximately 150 potential UCMR 3 contaminants. [FN4: 76 Fed. Reg. at

11,717.] The list was then pared down to eliminate those contaminants with no currently available 

methods, or methods that would not be ready in time for UCMR 3 monitoring and those 

contaminants that had been included in UCMR 1 or UCMR 2.[FN5: Id.] This left EPA with 35 

analytes, which were then prioritized using health effects data and other critical endpoints to arrive 

at the final proposed list of30 analytes. [FN6: Id.] Vanadium is included. 

PWSs collect the data, which are processed by approved EPA laboratories. The data are posted to 

EPA's web-based Safe Drinking Water Accession and Review System (SDW ARS). PWSs review the 

data. If the PWS rejects some or all of the data, an explanation is required.These data will help the 

EPA decide which substances to move forward with in promulgating new national primary drinking 

water standards.

More specifically, the UCMR 3 plan would require approximately 4,800 utilities to start the third 

round of Assessment Monitoring in 2013 for 30 unregulated contaminants, including vanadium. 

Monitoring for vanadium would occur at (1) the entry point to the water distribution system 

(EPTDS) and (2) the maximum residence time in the distribution system (DSMRT). The minimum 

reporting level is proposed at 0.2 micrograms per liter (~lg/L). At the choice of the PWS and its 

approved laboratory, one of three methods can be used to determine the occurrence of vanadium in 

the water samples: (1) EPA Method 200.8 Determination of Trace Elements in Waters by 

Inductively Coupled Plasma Mass Spectrometry, Version 5.4.1; (2) ASTM D5673- 10, Standard Test 

Method for Elements in Water by Inductively Coupled Plasma-Mass Spectrometry; or (3) SM 3125, 

Metals by Inductively Coupled Plasmas/Mass Spcctometry (1997).

When the CCL3 was published, EPA provided a summary of vanadium's listing, which included the 

Agency's assessment that additional data was needed before it could proceed with a regulatory 
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January 2012

34010 EPA Method 200.8 Rev 5.4 - Metals Page 167 of 401

determination evaluation. [FN7: 74 Fed. Reg. at 51,861.] The Agency characterized its data needs for 

vanadium as follows: 

[Table: see PDF docket ID EPA-HQ-OW-2009-0090]

With respect to vanadium's occurrence classification, the "2" notation indicated that EPA 

considered the data to be incomplete. For example, there was only limited PWS monitoring data (i. 

e., ground water systems only), spatial or geographical data limitations, and/or a small sample size. 

As such, EPA concluded that additional monitoring data was needed by the Agency, and this

proposed rule supports that effort. [FN8: 74 Fed. Reg. at 51,859.] In comments submitted to EPA 

on vanadium's proposed inclusion on the CCL3, VPRA commented that the occurrence data that 

EPA was relying on at that time were insufficient to warrant regulation under the SWDA. 

Response: Please see response to comment code 34010 EPA Method 200.8 Rev 5.4 - Metals.

Commenter Name: John W. III Hillbert 

Commenter Organization: Vanadium Producers and Reclaimers Association (VPRA) 

Letter ID: 0059

Comment ID: 31862

Comment Code: 34010

Comment: B. Analytical Procedures

The most sensitive technique for determining concentrations of vanadium in water is inductively 

coupled plasma-mass spectroscopy, for which there are several acceptable standards including those 

proposed by EPA: 

* EPA 200.8, "Determination of Trace Elements in Waters and Wastes by Inductively Couples 

Plasma-Mass Spectrometry," version 5.4, US Environmental Protection Agency, 1994;

* ASTM D5673-10, "Standard Test Method for Elements in Water by Inductively Coupled PlasmaMass Spectrometry," ASTM International, West Conshohocken, PA, 2010; and

* SM 3125, "Metals by Inductively Coupled Plasmas/Mass Spectrometry," 1997.

Based on our review of these standards, we believe the EPA 200.8 standard is the most 

comprehensive and best suited for measuring vanadium in drinking water with the following 

considerations. Only laboratories sufficiently experienced and qualified in environmental sampling 

and metal analysis at trace levels, i. e., laboratories that routinely perform and meet quality assurance 

checks should be contracted by the PWSs. The proposed reporting limit of 0.2 ug/L will present a 

challenge for most instruments and may not be feasible for some laboratories. Proper quality control 

protocols should be instituted to demonstrate reliable quantification at or below the minimum 

reporting limit, and this value must fall within the calibration limits (i. e., there must be calibration 

points below 0.2 ug/L). All reagents should be of the highest available purity, and instrument 

parameters should be optimized to provide the most accurate data possible. 
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ICP-MS is incapable of determining or differentiating vanadium species present in the samples. In 

order to obtain sufficiently comprehensive information, VPRA recommends that EP A require the 

steps described below to determine the nature of the vanadium species in the water test samples. We 

do not believe these measures are onerous, yet they will serve critical functions.

1. Determine oxidation states: Given the aforementioned differences in biological activity between 

V(IV) and V(V), an effort to determine the concentrations of the individual oxidation states is 

necessary. The oxidation state of the metal depends primarily on the pH of the water, reduction 

potential, and the presence of oxidants or antioxidants. It has been demonstrated that acidification 

can affect solution speciation including the reduction of V(V) to V(IV) under certain conditions 

(such as a low dissolved oxygen concentration and the presence of reducing ligands) (Tracey, 2007).

This effect should be considered when performing speciation analysis of samples, and effort should 

be made to identify and quantify any potentially reactive constituents (including dissolved oxygen) to 

the fullest practical extent. It is recommended that EPA investigate the following techniques for 

determining concentrations of the oxidation states. 1& Minelli et. al. reported a method for resolving 

V(IV) and V(V) via selective elution of V(IV) from an appropriately conditioned anionic exchange 

column (Minelli, 2000). ICP-MS can then be used to determine the concentration of total vanadium 

in the original sample as well as the concentration of isolated V(lV) in the eluted sample. Under this 

method, the conditioned anionic-exchange columns can be taken into the field, where the acidified 

solution can be applied immediately after collection. The vanadium species on these columns will be 

stable from oxidation or reduction during transportation for at least several days.

* Chen et. al. recently reported a technique using ion chromatography to resolve 

ethylenediaminetetraacetic acid (EDT A) complexes of the individual V(IV) and V(V) species, 

formed on-column. Concentrations were then determined by ICP-MS.

*EPA Method 6800, "Elemental and Speciated Isotope Dilution Mass Spectroscopy", 2007, 

describes a technique for speciated isotope dilution mass spectroscopy (SIDMS). This method uses 

ion chromatography to separate metals of different oxidation states, spiked with known quantities of 

an isotopically-enriched sample of a particular oxidation state. ICP-MS (or another suitable mass 

spectroscopy technique) is then used to determine the isotopic ratio, which, when compared to the 

naturally occurring isotopic ratio, can be used to calculate the concentrations of the oxidation states. 

2. Measure pH, reduction potential, ionic strength and concentrations of other dissolved ions in the 

water for sufficient sample characterization and for assessment of vanadium speciation: The 

equilibrium between different protonation states of vanadium species (e.g., H2V04-, Hvol-, and 

VO}-) is primarily dependant upon the pH of the water and the presence of other ligands and ions. 

Given the sensitivity of the equilibrium to the sample conditions and the dynamic nature of these 

species, it may not be practical to attempt to analytically determine their concentrations. However, 

properties of the water samples that effect the equilibrium state should be recorded as to allow a 

reasonable approximation, including measurements of pH, reduction potential, ionic strength, 

dissolved oxygen levels, dissolved organic content (DOC) and dissolved concentrations of major 

anions (i. e., ammonium, nitrate, phosphate, sulfate, and halides), major cations (i.e., calcium, 

magnesium, sodium, and potassium), and other metals expected to be in the water at relevant levels, 

including aluminum, iron, manganese, and zinc. The identities and concentrations of any additives 

introduced into the water supply should also be reported. * * * * *
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34010 EPA Method 200.8 Rev 5.4 - Metals Page 169 of 401

 Should EPA require additional analysis or further information on any matters discussed in these 

comments, please do not hesitate to contact us. 

Sincerely yours, John W. Hilbert III President, VPRA 

References

Agency for Toxic Substances and Disease Registry (ATSDR), "Draft Toxicological Profile for 

Vanadium," Sept. 2009.

Bosque-Sendra, J. M.; Valencia, c.; Boudra, S. Fresenius J Anal. Chem. 1998,360,31-37.

Chen, Z.: Rahman, M. M.; Naidu, R. J Anal. At. Spectrom. 2007,22,811-816.

Crans, D. c.; Bunch, R. L.; Theisen, L. A. JAm. Chem. Soc. 1989, 111,7597-7607.

Crans, D. c.; Willging, E. M.; Butler, S. K.; JAm. Chem. Soc. 1990a, 112,427-432.

Crans. D. C.; ScheIble, S. M. Biochemistry 1990b, 29, 6698-6706.

Crans, D. c.; Simone, C. M.: Holz, R. C.; Que, L., Jr.; BiochemistlY 1992, 31, 11731-11739.

Crans. D. C.; Amin, S. S.; Keramidas, K. D. Vanadium in the Environment, Part 1: Chemistry and 

Biochemistry; Nriagu, J. 0., Ed.: Wiley-Interscience: New York, NY, 1998. 

Hamada, T. Vanadium in the Environment, Part 1: Chemistry and Biochemistry; Nriagu, J. 0., Ed.; 

Wiley-]nterscience: New York, NY, 1998.

Leonard, A.; Gerber, G. B. Mutation Res. 1994, 317, 81-88.

Minelli, L; Veschetti, E.; Giammanco, S.; Mancini, G.; Ottaviani, M. Microchem. J 2000,67, 83-90.

ShefteL V. O. Indirect Food Additives and Polymers: Migration and Toxicity; CRC Press: Boca 

Raton, FL, 2000.

Thomas, K. W.; Pellizzari, E. D.; Berry, M. R.; J E'Cpo. Anal. Environ. Epidemiol. 1999,9,402- 413.

Thompson, K.H.; Battell, M.; McNeil, J. H. Vanadium in the Environment, Part 2: Health Effects; 

Nriagu, J. 0., Ed.; Wiley-Interscience: New York, NY, 1998.

Tracey, A. S.; Willisky, G. R.; Takeuchi, E. Vanadium: Chemistry, Biochemistry, Pharmacology and 

Practical Applications; CRC Press: Boca Raton, FL, 2007.

US EPA. Health Effects Assessment for Vanadium and Compounds. U. S. Environmental 

Protection Agency, Washington, D.C., EPA/600/8-88/061 (NTIS PB88176383), 1987.

Willi sky, G. R.; White, D. A.; McCabe, B. C. J BioI. Chem. 1984,259,13273-13281.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34010 EPA Method 200.8 Rev 5.4 - Metals Page 170 of 401

World Health Organization (WHO), Vanadium, Environmental Health Criteria, vol. 81, World 

Health Organization, Geneva, 1988.

Zhong, B. Z.: Gu,.Z. W.; Wallace, W. E: Whong, W. Z.; Ong, T. Mutation Res. 1994,312,35- 42.

Response: Please see response to comment code 34010 EPA Method 200.8 Rev 5.4 - Metals.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32084

Comment Code: 34010

Comment: The UCMR3 proposal includes digestion of all metal samples. It is not clear from the 

UCMR3 proposal how this approach assures UCMR3 will achieve its goal, e.g., an accurate 

reflection of observed occurrence of the metal concentrations in drinking water. If digestion is 

retained in the final UCMR3, the agency should provide a clear rationale. The agency will also need 

to revise its current LCMRL determinations to account for the digestion step. To the best of our 

knowledge, the LCRML determinations used for the metals do not take digestion into account and 

may therefore be inappropriately low.

Response: Digestion of all metals samples was included in UCMR 3 to ensure that total metal 

concentrations were being determined.

EPA has completed a multi-laboratory study of the MRLs for each of the metals when using 

digestion. The MRL results were lower (i.e., the method sensitivity was improved), in all cases, for 

the digested samples than those observed without the digestion step. The complete results are 

available in UCMR 3 Laboratory Approval Requirements and Information Document, Version 2.0., 

EPA 815-R-11-003, January 2012, posted in the docket for this regulation. 
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January 2012

34030 SM 3125 (1997) - Metals Page 171 of 401

Comment Code: 34030 SM 3125 (1997) - Metals

Individual Comments

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32081

Comment Code: 34030

Other EPA Comment Codes and Descriptions: 35030 SM 4110D (1997) - Chlorate 

Comment: EPA should also cite the most recent version of Standard Methods,whether citing 

4110D or 3125, so as to include more stringent quality control than is reflected in older versions of 

these methods. Additional quality control is consistent with EPA’s desire for high quality UCMR3 

data.

Response: Regarding comments about EPA's use of outdated alternate methods cited in the 

proposed rule, EPA agrees that outdated versions of SM4110D and SM3125 were cited in the 

proposal. These have been corrected to the 2005 versions of both methods. 
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34040 Other Methods - Metals Page 172 of 401

Comment Code: 34040 Other Methods - Metals

Individual Comments

Commenter Name: John W. III Hillbert 

Commenter Organization: Vanadium Producers and Reclaimers Association (VPRA) 

Letter ID: 0059

Comment ID: 31860

Comment Code: 34040

Comment: V. Specific Monitoring Recommendations 

With these considerations in mind, the following procedures and the rationale for implementing 

them are provided for EPA's consideration: 

A. Sampling Procedures 

EPA is proposing that water samples should be collected in accordance with established procedures 

for dissolved metal analysis.[FN10: See references under proposed analytical methods EPA 200.8, 

ASTM D5673-IO, and SM 3125.] VPRA would like to emphasize that these procedures call for 

acidification of samples as a preservation technique. Given that acidification has the potential to 

change the valence of the vanadium from what is collected (Tracey, 2007) and can potentially alter 

ligand behavior, a parallel sample of water that will not be acidified should also be collected. 

Measurements such as pH, reduction potential, ionic strength, dissolved oxygen levels, dissolved 

organic content, dissolved concentrations of major anions (i. e., ammonium, nitrate, phosphate, 

sulfate, and halides) and vanadium (IV & V) speciation should be taken from a separate, respective 

subsample without acidifIcation. VPRA recommends a sampling volume of greater than 200 mL. 

In addition, the following precautions should be taken to avoid external contamination. Exposure to 

atmospheric oxygen can cause oxidation of V(IV) to V(V). In order to avoid altering the samples 

during collection, efforts should be taken to minimize exposure to the atmosphere and sample 

bottles should be completely filled without any trapped air. All samples should be passed through a 

0.45-um fIlter to remove sediments and suspended particles before acidification. The filters should 

be cleaned with nitric acid and deionized water before use, and rinsed with a portion of the sample 

before filtration. Collection bottles should also be thoroughly cleaned with nitric acid and deionized 

water, and rinsed with portions of the filtered sample before collection. Sulfuric acid must be 

avoided for any process or equipment used in vanadium analysis; commercial sulfuric acid is 

manufactured with vanadium catalysts, and is consequently contaminated with trace amounts of 

vanadium. 

Response: Please see response to comment code 34010 EPA Method 200.8 Rev 5.4 - Metals.
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34050 Sampling Locations - Metals Page 173 of 401

Comment Code: 34050 Sampling Location - Metals

Summary Response to Comments on Sampling Location - Metals: 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 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. 

With respect to chlorate, since chlorate may occur as a source water contaminant, as a result of 

water treatment additives (e.g., contaminated hypochlorite solutions), and/or as a known oxyhalide 

disinfection by-product (DBP), monitoring at both the EPTDS and DSMRT will provide EPA with 

the range of human exposures to this contaminant in drinking water. In addition, if chlorate is 

present as a result of disinfectant reactions, the concentration may increase the longer the water is in 

contact with that disinfectant. EPA plans to compare the aggregated concentration data from the 

two sample points to determine if there is a significant difference in the concentrations and to 

correlate the occurrence with the type of disinfection used at the PWS. This information will assist 

EPA in determining an appropriate sampling strategy if a decision to regulate chlorate is made. 

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, 1999; Gallagher et al., 1994);

* photodecomposition of chlorine dioxide (Bolyard et al., 1993; Gallagher et al., 1994; Bergmann 

and Koparal, 2005);
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34050 Sampling Locations - Metals Page 174 of 401

* the use of chlorate-contaminated hypochlorite solutions (Bolyard et al., 1992; Bolyard et al., 1993; 

Gordon et al., 1993; Gordon et al., 1995; Gordon et al., 1997; USEPA, 1999; WHO, 2005; Snyder, et 

al., 2009);

* the use of ozone with residual chlorine (Siddiqui, 1996; von Gunten, 2003); and 

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

Koparal, 2005).

For these reasons, EPA believes it is necessary to investigate the prevalence and persistence of 

chlorate both at EPTDS and DSMRT locations and to correlate the occurrence with the type of 

disinfection. 

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. Snyder 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. Snyder 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.

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.

Fairbridge, R.W. 1972. The Encyclopedia of Geochemistry and Environmental Sciences, 

Encyclopedia of Earth Sciences Series, Volume IVA. Van Nostrand Reinhold Company, New York.

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. Water Research 

Foundation. 

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.

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 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, 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.

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 
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34050 Sampling Locations - Metals Page 175 of 401

funded by AWWA and WRF. Available on the Internet at: 

http://www.awwa.org/files/GovtPublicAffairs/PDF/HypochloriteAssess.pdf. 

USEPA. 1999. Alternative Disinfectants and Oxidants Guidance Manual. Office of Water. EPA 

815-R-99-014. Available on the Internet at: 

http://water.epa.gov/lawsregs/rulesregs/sdwa/mdbp/mdbptg.cfm. 

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.

EPA has revised UCMR 3 to clarify the location of the DSMRT sampling. 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).

Monitoring the metals at both the EPTDS and DSMRT is designed to provide a more accurate 

indication of the levels of these contaminants that the public is consuming. EPA agrees that the 

UCMR is not the appropriate program to perform research into the mechanisms for the 

accumulation or release of metals in the distribution system. 

Individual Comments

Commenter Name: David Chang 

Commenter Organization: Golden State Water Company (GSWC)

Letter ID: 0054

Comment ID: 31632

Comment Code: 34050

Comment: * GSWC recommends that metals only be measured at entry point to distribution 

system (EPTDS) since metals are unlikely to change through distribution system. We appreciate the 

Agency's consideration of our comments. 

Respectfully submitted, David Chang, Ph. D., P.E. Vice President, Environmental Quality

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Phillip W. Holderness 

Commenter Organization: California-Nevada Section, American Water Works Association (CANV AWWA)

Letter ID: 0055

Comment ID: 31638

Comment Code: 34050
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34050 Sampling Locations - Metals Page 176 of 401

Comment: * CA-NV AWWA recommends that metals only be measured at entry point to 

distribution system (EPTDS) since metals are unlikely to change through distribution system. We 

appreciate the Agency's consideration of our comments. 

Respectfully submitted, 

Phillip W. Holderness, Chair California-Nevada Section of the American Water Works Association 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31685

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: EPA is requesting comment on DSMRT, distribution system maximum residence time, 

sampling for the metals and chlorate. [...] NMED Comment

NMED has no comment on the DSMRT sampling for metals and chlorate. 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Deborah H. Metz 

Commenter Organization: Greater Cincinnati Water Works (GCWW)

Letter ID: 0085

Comment ID: 31707

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: 2. Distribution system monitoring 

a. Use of Disinfection By-products Rule's (DBPR) Distribution System Maximum Residence Time 

(DSMRT) locations for metals may not be appropriate. Additionally, Entry Point to the Distribution 

System (EPTDS) as wells as DSMRT sampling locations may not be appropriate for chlorate. We 

recommend using a representative location or an average Distribution System Residence Time 

(DSRT) location for such sampling. These average residence time sites were identified by systems 

that performed lOSE under the Stage 2 D/DBP Rule. This is significant in the context of EPA's 

health risk levels of 1 in 10,000. Normally, maximum residence times are at the distil end of a 

distribution system and may represent the absolute worst location, and population served beyond 

that point is normally minimal.

Response: Please see response to comment code 34050 Sampling Location - Metals.
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34050 Sampling Locations - Metals Page 177 of 401

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31773

Comment Code: 34050

Comment: AMWA does not support EPA’s proposal for taking metals samples in the distribution 

samples for reasons detailed later in these comments. Please see also AMWA’s comments under 

Comments 12 and 13, below. 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31799

Comment Code: 34050

Comment: Other than Cr+VI, the proposal to sample other metals at DSMRT should be removed 

from UCMR-3. The issue of metal accumulation and release within the distribution system are 

research questions that should be addressed under the rTCR as part of the Distribution System 

Research and Information Collection Partnership. 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31817

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: Lastly, collected distribution system maximum residence time (DSMRT) data for metals 

and chlorate will not likely be solely dependent on water source and treatment, but may be greatly 

influenced by PWS infrastructure and operations. At smaller PWSs, water operators sometimes lack 

knowledge of distribution hydraulics, resulting in site choices which may not represent the oldest 

water. Nevertheless, the DSMRT sampling adds exposure information to the collected data.

The Minnesota Department of Health appreciates the opportunity to review and comment and 

hopes for continued discussion in order to most efficiently implement this regulation. If you have 

questions, please contact Mr. David Rindal, Community Public Water Supply Unit, Drinking Water 

Protection Section, at 651/201-4660.

Sincerely,
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34050 Sampling Locations - Metals Page 178 of 401

Randy Ellingboe, P.E., Program Manager Drinking Water Protection Section Environmental Health 

Division P.O. Box 64975 St. Paul, Minnesota 55164-0975

Response: EPA appreciates your comment and has included DSMRT sampling. We believe that 

operators understand their systems sufficiently to pick a sampling location that represents some of 

the oldest water, which will satisfy the needs of this rule.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31828

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: Sampling location

Under40 CFR 141.40(a)(4)(i)(C), the EPA requires systems to collect metal and chlorate samples at 

distribution system MRT sampling locations. If these locations are not defined, EPA requires PWS 

to collect samples at locations that best represents the maximum residence time in the distribution 

system.

The TCEQ notes that the EPA's sample tracking protocols under UCMR 2 inadequately tracked 

distribution system sites, and recommends that the EPA revisit its quality control review processes 

as they relate to distribution system sample locations.

Response: For UCMR 2, the Texas Commission on Environmental Quality selected all of the 

distribution sampling locations for the State of Texas. EPA is unaware of any issue related to 

tracking of distribution samples in UCMR 2. Please see response to comment code 34050 Sampling 

Location - Metals.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31831

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: Maximum residence time sampling (MRT)

In addition to EP monitoring, EPA proposes to sample the four metals-cobalt, molybdenum, 

vanadium, and strontium-as well as chlorate, at one distribution system MRT sampling point per 

treatment plant If the system is subject to the Stage 2 Disinfectants and Disinfection Byproducts 

Rule (DBP2), then samples for the metals and chlorate must be collected at the MRT sampling 

location identified for that rule. 
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The TCEQ notes that there may be systems just starting DBP2 sampling during the time period of 

UCMR3 sampling and recommends that the EPA provide flexibility to these systems in order to 

spread the cost impact out over the greatest time period possible. 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31836

Comment Code: 34050

Comment: Similarly, Riverside does not support the monitoring for the four metals at the DSMRT 

location and recommends that this requirement be removed from UCMR3. The proposed UCMR3 

document does not discuss the scientific reasoning to include DSMRT monitoring for the metals. 

The UCMR preamble only states that DSMRT monitoring is listed "to assess any potential 

contribution from the distribution system." A key monitoring objective of the UCMR3 program is 

to collect occurrence data of unregulated contaminants in treated drinking water at the EPTDS 

which is primarily representative of the source water and not contributions from the distribution 

system. The information collected for metals occurrence at DSMRT locations will be system specific 

and will require additional information on the infrastructure, source water quality, flow dynamics, 

and other physical and chemical parameters to place distribution- source materials data in 

perspective

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31841

Comment Code: 34050

Comment: 12. Metals samples at distribution system maximum residence time location AMWA

disagrees with EPA’s proposal for utilities to sample for metals at the maximum distribution system 

residence time (DSMRT) for two reasons:

* There is neither enough data nor research to support the additional cost to utilities for sampling 

for metals in the distribution system. 

* Following the recommendation of the Total Coliform Rule Agreement in Principle, the Research 

and Information Collection Partnership has identified the issue of metals accumulation and release 

from distribution system scales and sediments as a lower research priority. AMWA suggests that if 

EPA wants to further research this issue, additional funding should be provided to conduct a 

separate research project outside the UCMR.

Response: Please see response to comment code 34050 Sampling Location - Metals.
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34050 Sampling Locations - Metals Page 180 of 401

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31850

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: 6.0 Chlorate and Metals Monitoring at DSMRT 

EPA is proposing that chlorate and the four metals, cobalt, molybdenum, vanadium, and strontium 

be monitored at the entry point to the distribution system (EPTDS) and the distribution system 

maximum residence time (DSMRT). EPA is requesting comment on the DSMRT sampling for the 

metals and chlorate.

6.1 Chlorate and Metals DSMRT Monitoring 

EPA is proposing that chlorate, and the metals - cobalt, molybdenum, vanadium and strontium be 

monitored at the EPTDS and DSMRT locations (FR page 11717 Exhibit 2, 11723, 11725, 141.40 

(a)(3) Table1, and 141.40 (a)(4)(i)(c)). EPA does not provide the basis for requiring testing for 

chlorate and the metals at the DSMRT location. The only discussion provided for the DSMRT 

monitoring appears in the preamble as shown by the following excerpts (FR page 11723):

* "EPA is proposing revisions to UCMR that would require systems to report all data elements with 

each sample (including Data Element 6 (Disinfectant Type)) since Assessment Monitoring within 

the distribution system is proposed and since the information on disinfectant type would be useful 

in the Agency’s evaluation of results for chlorate and the metals on List 1 - Assessment 

Monitoring...."

* "Chlorate is being monitored at both the EPTDS and the DSMRT to determine the magnitude of 

chlorate increases in the distribution system. The metals are monitored at both locations to assess 

any potential contribution from the distribution system." 

Under UCMR2, the nitrosamines were monitored at the EPTDS and DSMRT locations because of 

the potential formation of nitrosamine species (e.g., N- nitrosodimethylamine, NDMA) as a 

disinfection by-product. Because of the close relationship of potential nitrosamine species formation 

and disinfectant oxidants, collecting information on the type of disinfectant is reasonable. However, 

EPA does not provide the reasoning for requiring information on the type of disinfectant and levels 

of chlorate or the metals detected at either the EPTDS or DSMRT locations. EPA needs to provide 

the rationale for requesting disinfectant type specific for chlorate and the metals relative to the 

detection of these analytes.

OCWD does not support monitoring for chlorate or the four metals at the DSMRT location. In the 

preamble, EPA only provides two descriptive sentences stating that chlorate and the four metals will 

be monitored at the DSMRT location as shown above (excerpt from FR page 11723). EPA does not 

provide a firm scientific foundation that chlorate "increases in the distribution system," that is,

increasing in concentration from the point of entry to a location downstream that best represents 
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34050 Sampling Locations - Metals Page 181 of 401

the maximum residence time in the distribution system. There are no scientific studies or research 

projects referenced in the proposed UCMR3 document that show chlorate increases in the 

distribution system are due to disinfectant oxidants (as was provided for NDMA monitoring under 

UCMR2), thus warranting DSMRT monitoring in UCMR3. If DSMRT chlorate monitoring is 

warranted, EPA needs to provide the basis and criteria that triggers the need for testing at the 

DSMRT location. 

Similarly, OCWD does not support the monitoring for the four metals at the DSMRT location and 

recommends that this requirement be removed from UCMR3. The proposed UCMR3 document 

does not discuss the scientific reasoning to include DSMRT monitoring for the metals. The 

preamble only states that DSMRT monitoring is listed "to assess any potential contribution from the 

distribution system. "A key monitoring objective of the UCMR3 program is to collect occurrence 

data of unregulated contaminants in treated drinking water at the EPTDS which is primarily 

representative of the source water and not contributions from the distribution system. The 

information collected for metals occurrence at DSMRT locations will be system specific and will 

require additional information on the infrastructure, source water quality, flow dynamics, and other 

physical and chemical parameters to place distribution-source metals data in perspective. EPA and 

the Water Research Foundation have developed a priority list of research and data needs focused on 

the distribution system. Formed in January 2009, the Distribution System Research and Information 

Collection Partnership, not UCMR3, is the appropriate forum to address the occurrence of the four 

metals in the distribution system. The Partnership has identified "accumulation and release of 

contaminants from distribution scales and sediment" as an issue to be addressed through research 

and information collection activities.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: John W. III Hillbert 

Commenter Organization: Vanadium Producers and Reclaimers Association (VPRA) 

Letter ID: 0059

Comment ID: 31861

Comment Code: 34050

Comment: To verify natural background levels, VPRA supports EPA's proposal that ground water 

systems with multiple entry points to the distribution system (EPTDSs) be permitted to sample at 

representative sampling locations for each ground water source, with a determination that "the 

proposed representative well must be one of the higher annual volume producing and more 

consistently active wells in the representative array."[FN11: See proposed § 141.35( c )(3 )(ii).] 

Similarly, VPRA supports EPA's proposal to require distribution system maximum residence time 

(DSMRT) sampling in order to fully understand how water treatments and distribution systems 

effect the vanadium species present in drinking water.

Response: EPA appreciates your support and has included representative sampling and DSMRT 

sampling. 

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA
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34050 Sampling Locations - Metals Page 182 of 401

Letter ID: 0066

Comment ID: 31869

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: Currently, the proposed sampling locations include entry point to the distribution 

system (EPTDS) and, for metals and chlorate, distribution system mean residence time (DSMRT). 

Expanding the sampling locations to include the source prior to treatment would provide 

information on the effects of treatment on contaminants. This additional sampling will have added 

analytical costs, but the additional information gathered should be very valuable. There should be 

little additional costs for sample collection and program administration due to collection of 

untreated source samples. These two changes would expand the utility of the UCMR process to help 

identify the impact of treatment on contaminant occurrence. The treatment processes currently used 

in SDWIS could be used as a guide to create a list of treatment processes for selection under data 

element 6.

Response: Congress designed the UCMR program to monitor for unregulated contaminants in the 

nation's drinking water. As a result, EPA’s priority is occurrence at the EPTDS and within the 

distribution system where exposure risks are greatest.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31893

Comment Code: 34050

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: 6.0 Chlorate and Metals Monitoring at DSMRT 

EPA is proposing that chlorate and the four metals, cobalt, molybdenum, vanadium, and strontium 

be monitored at the entry point to the distribution system (EPTDS) and the distribution system 

maximum residence time (DSMRT). EPA is requesting comment on the DSMRT sampling for the 

metals and chlorate.

6.1 Chlorate and Metals DSMRT Monitoring 

EPA is proposing that chlorate, and the metals - cobalt, molybdenum, vanadium and strontium be 

monitored at the EPTDS and DSMRT locations (FR page 11717 Exhibit 2, 11723, 11725, 141.40 

(a)(3) Table1, and 141.40 (a)(4)(i)(c)). EPA does not provide the basis for requiring testing for 

chlorate and the metals at the DSMRT location. The only discussion provided for the DSMRT 

monitoring appears in the preamble as shown by the following excerpts (FR page 11723):

*"EPA is proposing revisions to UCMR that would require systems to report all data elements with 

each sample (including Data Element 6 (Disinfectant Type)) since Assessment Monitoring within 

the distribution system is proposed and since the information on disinfectant type would be useful 

in the Agency’s evaluation of results for chlorate and the metals on List 1-Assessment Monitoring..." 
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34050 Sampling Locations - Metals Page 183 of 401

*"Chlorate is being monitored at both the EPTDS and the DSMRT to determine the magnitude of 

chlorate increases in the distribution system. The metals are monitored at both locations to assess 

any potential contribution from the distribution system." 

Under UCMR2, the nitrosamines were monitored at the EPTDS and DSMRT locations because of 

the potential formation of nitrosamine species (e.g., Nnitrosodimethylamine, NDMA) as a 

disinfection by-product. Because of the close relationship of potential nitrosamine species formation 

and disinfectant oxidants, collecting information on the type of disinfectant is reasonable. However, 

EPA does not provide the reasoning for requiring information on the type of disinfectant and levels 

of chlorate or the metals detected at either the EPTDS or DSMRT locations. EPA needs to provide 

the rationale for requesting disinfectant type specific for chlorate and the metals relative to the 

detection of these analytes.

ACWA does not support monitoring for chlorate or the four metals at the DSMRT location. In the 

preamble, EPA only provides two descriptive sentences stating that chlorate and the four metals will 

be monitored at the DSMRT location as shown above (excerpt from FR page 11723). EPA does not 

provide a firm scientific foundation that chlorate "increases in the distribution system," that is, 

increasing in concentration from the point of entry to a location downstream that best represents 

the maximum residence time in the distribution system. There are no scientific studies or research 

projects referenced in the proposed UCMR3 document that show chlorate increases in the 

distribution system are due to disinfectant oxidants, thus warranting DSMRT monitoring in 

UCMR3. If DSMRT chlorate monitoring is warranted, EPA needs to provide the basis and criteria 

that triggers the need for testing at the DSMRT location.

Similarly, ACWA does not support the monitoring for the four metals at the DSMRT location and 

recommends that this requirement be removed from UCMR3. The proposed UCMR3 document 

does not discuss the scientific reasoning to include DSMRT monitoring for the metals. The 

preamble only states that DSMRT monitoring is listed "to assess any potential contribution from the 

distribution system." A key monitoring objective of the UCMR3 program is to collect occurrence 

data of unregulated contaminants in treated drinking water at the EPTDS which is primarily 

representative of the source water and not contributions from the distribution system. The 

information collected for metals occurrence at DSMRT locations will be system specific and will 

require additional information on the infrastructure, source water quality, flow dynamics, and other 

physical and chemical parameters to place distribution-source metals data in perspective. EPA and 

the Water Research Foundation have developed a priority list of research and data needs focused on 

the distribution system. Formed in January 2009, the Distribution System Research and Information 

Collection Partnership, not UCMR3, is the appropriate forum to address the occurrence of the four 

metals in the distribution system. The Partnership has identified "accumulation and release of 

contaminants from distribution scales and sediment" as an issue to be addressed through research 

and information collection activities.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Yone Akagi

Commenter Organization: City of Portland, Oregon 

Letter ID: 0088

Comment ID: 32001
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Comment Code: 34050

Comment: 4. EPA has proposed measuring the metals at the DPBMAX site in the distribution 

system.

PWB is very interested in research to understand metals in the distribution system and have recently 

completed some of this work in our own system. As an unfiltered system we are concerned about 

accumulation and release of contaminants from distribution system scales and sediments. However, 

we are not certain that this research is appropriate to be done under the UCMR. 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32040

Comment Code: 34050

Comment: 5. Requiring monitoring for the listed metals only at the EPTDS(s) for each

participating water system.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080

Comment ID: 32092

Comment Code: 34050

Comment: AWWA does not support the monitoring for the metal analytes at the DSMRT 

locations and EPA should remove this requirement from the final UCMR3. Separate research 

questions are relevant to metal concentrations in the distribution system but monitoring at the 

DSMRT will increase the cost of UMCR3 monitoring but will not be informative because it will only 

represent a single point in the distribution system and only a few points in time. EPA and the Water 

Research Foundation developed a list of priority research and information collection needs through 

the Distribution System Research and Information Collection Partnership. The priorities document 

identifies relevant data gaps and research strategies that are appropriate vehicles for understanding 

the occurrence of these metals in distribution systems.[FN17: 2010, EPA, Final Priorities of the

Distribution System Research and Information Collection Partnership.] 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080
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34050 Sampling Locations - Metals Page 185 of 401

Comment ID: 32101

Comment Code: 34050

Comment: 13.Distribution system maximum residence time monitoring for metals and chlorate?

As noted previously, it is not appropriate to monitor for the metal analytes at the DSMRT locations 

and EPA should remove this requirement from the UCMR3. There are research questions relevant 

to metal concentrations in the distribution system but monitoring at the DSMRT will substantially 

increase the cost of UMCR3 monitoring but will not be informative. EPA and the Water Research 

Foundation developed a list of priority research and information collection needs through the 

Distribution System Research and Information Collection Partnership. The priorities document 

identifies relevant data gaps and research strategies that are appropriate vehicles for understanding 

the occurrence of these metals in distribution systems.[FN21:2010, EPA, Final Priorities of the 

Distribution System Research and Information Collection Partnership.] 

Response: Please see response to comment code 34050 Sampling Location - Metals.
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34070 Health Effects - Metals Page 186 of 401

Comment Code: 34070 Health Effects - Metals

Individual Comments

Commenter Name: John W. III Hillbert 

Commenter Organization: Vanadium Producers and Reclaimers Association (VPRA) 

Letter ID: 0059

Comment ID: 31859

Comment Code: 34070

Comment: IV. Vanadium Species and their Toxicity 

In addition to the points raised above, the speciation of vanadium is critical because the nature of 

vanadium in aqueous solution is not straightforward. Vanadium minerals and oxides that dissolve 

into water will be hydrolyzed, oxidized or reduced to form a complex equilibrium of species 

dependant upon pH, concentration, and the presence of oxidants, antioxidants, chelators, ligands 

and other salts. These species will vary by oxidation state and degree of protonation, with the 

formation of oligomeric complexes (dimers, trimers, etc.) at higher concentrations (>0.1 millimolar 

(mM), or 5 mg/L) (Crans, 1998). Under typical environmental conditions, the vanadium will 

primarily exist in the +5 oxidation state as monomeric H2V04-, although a +4 oxidation state 

species can be present and stable under some conditions. 

The speciation of vanadium is critical because different forms of vanadium have different 

toxicological properties. For example, aqueous monomeric V(V) ions (e.g.vanadates, H2V04-, 

HVO42-, VO43- and V02+) are known to strongly inhibit the action of Na+, K+-ATPase and 

other phophatase enzymes, while the V(IV) ions (e.g.vanadyl, V02+) have a much weaker inhibitory 

effect (Willisky, 1984; Crans, 1989; Crans, 1992; Zhong, 1994, Leonard, 1994). Furthermore, the 

vanadate tetramer (V4012 4-) that forms at higher vanadium concentrations (> 1 mM) has no effect 

on phosphatases, but inhibits dehydrogenases (unlike the monomeric species, which have no effect) 

(Crans 1990a; 1990b). Given these differences in biological activity, monitoring efforts that do not 

discriminate between the different species of vanadium cannot provide a complete basis for a health 

assessment for safe drinking water.

A degree of caution should be exercised when reviewing literature reports of toxicological studies 

regarding vanadium. These studies often fail to differentiate between routes of ingestion, i. e., food, 

water, oil, or capsules. Doses delivered in food, oil or capsules likely consist of different vanadium 

species than those typically present in drinking water. Also, the vanadium concentration 

administered is often is too high; in many studies, vanadium doses are at concentrations of 1-10 mM 

(51-510 mg/L) (Thompson, 1998), which is four to five orders of magnitude higher than typical 

drinking water concentrations (1.2 ug/L). At these concentrations, the oligomeric forms become the 

dominant species, which, as mentioned above, have unique toxicology compared to the monomeric 

species that dominate at lower concentrations. Even the highest levels of vanadium found in natural 

freshwater (300 ug/L, or 5.9 uM) will not have appreciable amounts of oligomer content (cf. 92% 

monomer, 8% dimer content at 5.1 mg/L, or 1 00 uM) (Crans, 1998). Given the taste perception 

threshold of vanadium (0.8 mg/L) (Sheftel, 2000), it is unlikely that water containing vanadium at 

high enough concentrations to form significant amounts of oligomeric species would be ingested. 
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34070 Health Effects - Metals Page 187 of 401

Therefore, the relevance of studies using such highly concentrated doses to human drinking water is 

called into question. 

The method of administration should also be considered as a potential source of bias. EPA has 

stated that the absorption rate of ingested vanadium in humans is 0.1-1% (US EPA, 1987); animal 

studies have reported absorption rates as low as 0.1 % and as high as 25%, strongly dependant on 

dietary components such as carbohydrate type, fiber, protein concentration and electrolytes 

(Thompson, 1998). As such, doses administered by subcutaneous or intraperitoneal injection deliver 

significantly higher amounts of vanadium than does the ingestion of an identical dose. Without 

understanding the vanadium species present and the procedures involved in administering the doses, 

such studies are arguably meaningless when attempting to realistically evaluate the potential hazards

associated with vanadium in drinking water.

Response: Please see response to comment code 34010 EPA Method 200.8 Rev 5.4 - Metals.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34100 Vanadium Page 188 of 401

Comment Code: 34100 Vanadium

Individual Comments

Commenter Name: John W. III Hillbert 

Commenter Organization: Vanadium Producers and Reclaimers Association (VPRA) 

Letter ID: 0059

Comment ID: 31855

Comment Code: 34100

Comment: May 2,2011 Submitted via http://www.regulations.gov Water Docket U.S. 

Environmental Protection Agency Mail Code 282211 T 1200 Pennsylvania Avenue, NW

Washington, DC 20460 Re: Docket ID No. EPA-OW-2009-0090, Revisions to the Unregulated 

Contaminant Monitoring Regulations (UCMR 3) for Public Water Systems

Dear Sir or Madam:

The Vanadium Producers and Reclaimers Association (VPRA) [FN1: The Vanadium Producers and 

Reclaimers Association (VPRA) is a not-for-profit corporation representing the domestic vanadium 

industry in the United States on issues of importance to the industry including technology, trade, 

and health, safety and the environment.] appreciates the opportunity to submit comments to the 

U.S. Environmental Protection Agency (EPA or Agency) on its proposed rule, "Revisions to the 

Unregulated Contaminant Monitoring Regulations (UCMR 3) for Public Water Systems," 76 Fed. 

Reg. 11,713 (March 3,2011).

I. Executive Summary

VPRA is commenting on that aspect of the UCMR 3 plan that proposes to require approximately 

4,800 Public Water Systems (PWS) to monitor for certain unregulated contaminants, including 

vanadium, beginning January 1,2013. Vanadium is one of four metals being considered; the other 

metals are cobalt, molybdenum, and strontium. 

In earlier comments submitted to EPA during the development of the Third Contaminant Chemical 

List (CCL3), VPRA pointed out the lack of good occurrence data on vanadium. In this regard, there 

are two technical considerations that are raised by the current proposal that warrant additional 

program design elements for monitoring for vanadium, should EPA decide to include vanadium in 

this monitoring program. 

First, it should be recognized that concentrations of elemental vanadium in drinking water are 

attributed to a number of different sources, both natural and industrial, including the migration of 

ground and surface water through vanadium enriched soil and ore and the deposition of 

atmospheric vanadium from continental dust, marine aerosol, and volcanic emissions. Second, 

different forms of vanadium have different toxicological properties, and monitoring efforts that do 

not permit EPA to discriminate between the different species of vanadium cannot provide a 

complete basis for an assessment.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34100 Vanadium Page 189 of 401

Response: Please see response to comment code 34010 EPA Method 200.8 Rev 5.4 - Metals.

Commenter Name: John W. III Hillbert 

Commenter Organization: Vanadium Producers and Reclaimers Association (VPRA) 

Letter ID: 0059

Comment ID: 31858

Comment Code: 34100

Comment: III. Environmental Vanadium, Proposed Minimum Reporting Level, and Natural 

Exposure 

EPA has proposed the minimum reporting levels of 0.2 ~lg/L for vanadium.[FN9: 76 Fed. Reg. at 

11,734.] This value is particularly low given typical drinking water concentrations of less than 1 0 

~lg/L (WHO, 1988). EPA should anticipate widespread reporting, and appreciate that the ubiquity 

of naturally occurring vanadium in drinking water does not, in and of itself, indicate a potential

health concern. 

Specification that monitoring applies only to soluble forms of vanadium found in drinking water, 

including vanadium ions from vanadium salts, is important because, as EPA recognizes, vanadium is 

widely distributed in low abundance throughout the Earth's crust (US EP A, 1987). At an average 

concentration of 100 parts per million (ppm), it is as abundant as nickel and zinc (ATSDR, 2009). In

addition to the 65 minerals that contain vanadium, it is found in phosphate rocks, metal ores and 

crude oil. 

According to the Agency for Toxic Substances and Disease Registry (ATSDR), the occurrence of 

vanadium in groundwater is primarily due to the erosion of vanadium-containing rocks and soil, as 

well as the deposition of atmospheric vanadium (ATSDR, 2009). The primary sources of 

atmospheric vanadium include formation of continental dust, marine aerosols, volcanic emissions, 

and the burning of vanadium-containing coal and fossil fuels. Overall, the natural releases of 

vanadium into groundwater are far greater than anthropogenic sources.

Based on the natural deposition of vanadium in rocks and soils, the concentration of vanadium in 

surface and groundwater depends heavily on local geological conditions. Most fresh waters contain 

less than 3 ug/L (Hamada, 1998), but can range from 0.04 to 200 ug/L (ATSDR, 2009). A dietary 

study completed by EPA Region V found an average vanadium concentration of 1.2 ug/L in flushed 

tap water (Thomas, 1999). A study conducted by the US Geological Survey (USGS) on domestic 

well water collected between 1991-2004 found vanadium in 452 of 662 samples, with a median 

concentration of 1.29 ug/L (ATSDR, 2009).

Speciation is further desirable to avoid undue regulatory burdens on industry discharges in the 

future. Without recognition and characterization of existing background levels, industrial discharges 

could be held accountable for vanadium that they do not emit and this could threaten their 

continued ability to function in business. 

Response: Please see response to comment code 34010 EPA Method 200.8 Rev 5.4 - Metals.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34200 Molybdenum Page 190 of 401

Comment Code: 34200 Molybdenum

Individual Comments

Commenter Name:

Commenter Organization: Northern Kentucky Water District

Letter ID: 0060

Comment ID: 31648

Comment Code: 34200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: We understand that the Safe Drinking Water Act mandates that there must be 30

contaminants on the UCMR. Therefore when a contaminant is added to the UCMR, an existing 

contaminant must be removed. The decision on what contaminant to remove from the list of 30 

UCMR3 contaminants is difficult. Molybdenum is considered to be an essential element in the body 

with an estimated daily requirement. There seems to be more beneficial information available for 

Molybdenum than negative health effects. With this information available, it might be the least

controversial contaminant to remove from the list. 

Response: EPA believes that monitoring for molybdenum is justified. Molybdenum has a health 

risk level of 35 μg/L, based upon an IRIS RfD of 0.005 mg/kg/day. Molybdenum was previously 

detected in 8% of the drinking waters sampled in the National Inorganics and Radionuclides Survey 

at a maximum concentration of 180 μg/L and with a median concentration of 10 μg/L. It was also 

detected at 57% of the 3,297 sites sampled in the National Water Quality Assessment Program, at a 

maximum concentration of over 4,000 μg/L and with a median concentration of 3 μg/L. (76 FR 

11713). Chromium-6 (hexavalent chromium) and total chromium have been added to the list of 

contaminants to be monitored. In addition, sec-butylbenzene and n-propylbenzene have been 

removed from the list of contaminants to be monitored. Please see response to comment code 

38100 Chromium-6.

Commenter Name: Sandra Carey

Commenter Organization: International Molybdenum Association 

Letter ID: 0074

Comment ID: 31692

Comment Code: 34200

Comment: Please see attached file containing comment letter from the International Molybdenum 

Association about molybdenum, plus attachments. 

30 April 2011

TO: United States Environmental Protection Agency 

FROM: International Molybdenum Association 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34200 Molybdenum Page 191 of 401

RE: US-EPA Docket I.D.: EPA-HQ-OW-2009-0090

The International Molybdenum Association (IMOA) is an organization representing over 85% of 

molybdenum production, and all conversion capacity, in established markets. Our 19 members in 

the USA include Chevron Mining Company, Climax Molybdenum Company, Kennecott 

Molybdenum Company and Thompson Creek Metals Company. IMOA has noted that molybdenum 

is included as one of the 28 substances on the Unregulated Contaminant Monitoring Regulation list 

published in March 2011, for which there is a public comment period until 2 May.

In this respect we wish to comment as follows:

*The EU Reach Regulation technical dossier on molybdenum has very recently (March 2011) been 

published by the European Chemicals Agency, and is available on: 

http://apps.echa.europa.eu/registered/registered-sub.aspx . This dossier is a comprehensive risk 

assessment about the effects of molybdenum to the environment and to human health. Attached is 

the Chemical Safety Report for molybdenum (CAS No. 7439-98-7) which is a core output from the 

technical dossier. We would encourage US-EPA to refer to this new source of data where: i) many 

new studies were conducted in order to comply with the REACH requirements, and ii) studies have 

been ranked for scientific relevance and reliability as per the Klimisch et al. ranking system.

[FN1: Klimisch ranking system explanation, (extract from US-EPA HPV webpage about 

Determining the Adequacy of Existing Data http://www.epa.gov/hpv/pubs/general/datadfin.htm): 

Other methods are available for assessing "data adequacy", and one in particular has been recently 

proposed for use in Europe in developing the International Uniform Chemical Information 

Database (IUCLID). Klimisch et al. (1997) describe the method and propose that data evaluation be 

done systematically and that it include consideration of reliability, relevance, and adequacy. Klimisch 

et al. define adequacy as "the usefulness of data for risk assessment purposes", whereas in this 

document EPA uses the term to mean usefulness for hazard identification purposes. 

The method described in Klimisch et al. (1997) is similar in principle to EPA’s tiered approach in 

that both methods present specific criteria for evaluating existing data. In fact, the data reliability 

criteria presented by Klimisch and by EPA (in Tier I) are remarkably similar. The difference between 

the two approaches is in how the criteria are used.

Klimisch et al. use their criteria in the following scoring system for evaluating data reliability: 1 = 

reliable without restrictions; 2 = reliable with restrictions; 3 = not reliable; and 4 = not assignable. 

The Klimisch ranking system does not conflict with the EPA approach. Assigning a numerical value 

to each study is both useful and comprehensive; however, EPA believes using the same criteria as a 

screen (Tier I as described below) results in the appropriate "weeding out" of data/studies not useful 

in describing an endpoint. For example, studies assigned Klimisch reliability codes "3" or "4" would 

not advance to Tier II in the EPA approach, except for those cases in which a weight-of-theevidence analysis might be used.]

*IMOA made an initial submission to US-EPA in May 2008, when molybdenum was included in the 

Contaminant Candidate List 3. According to the US-EPA scoring criteria for inclusion in the CCL3, 

the key concern was a potential adverse risk to human health, apparently identified in a study 

(Kovalskiy et al., 1961) contained in the IRIS database. Our May 2008 submission seriously 

questioned the validity of the conclusions from that study, as you can read in the attached copy. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34200 Molybdenum Page 192 of 401

Since then, and with the EU REACH regulation as the main driver, the Kovalskiy study has been 

the subject of further scrutiny in terms of its scientific reliability and relevance for use as a basis for 

regulatory issues. We attach our ‘February 2010 Critical Review of Kovalskiy et al., 1961’. Doubtless 

this 24 page review will be of significant interest to you. It concludes that based on a variety of 

methodological and reporting deficiencies, the study is an unreliable reference for the assessment of 

potential adverse effects of molybdenum on human health. On that particular basis, inclusion of 

molybdenum in the UCMR 3 list is not warranted and is based on flawed science. 

*We would also like to inform you that IMOA commissioned a GLP 90-day repeated dose oral 

toxicity study according to OECD protocol 408, with additional reproductive toxicity parameters, 

using sodium molybdate as the test material. This study concluded very recently in the USA in 

March 2011. Prior to the 90-day study a 28-day range-finder study was also conducted. When the 

final reports of both these studies are available we will forward you a copy for your records and

review.

Response: EPA appreciates the new toxicological information on molybdenum and looks forward 

to reviewing the new study reports when they become available. Molybdenum has been identified as 

being among the heavy metals that can be mobilized from reservoir sediments containing iron and 

aluminum oxides and hydroxides. Therefore, the environmental fate and existing health and 

occurrence information indicate that additional monitoring is important. 

EPA also appreciates the discussion of the Klimisch ranking system versus that used in the 

development of CCL 3. However, these comments are more properly directed to the next CCL 

publications and not to this regulatory action. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34300 Cobalt Page 193 of 401

Comment Code: 34300 Cobalt

Individual Comments

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31901

Comment Code: 34300

Comment: Cobalt - Data on the occurrence of cobalt in NJ water supplies is limited, and UCMR3 

would provide this information. NJDEP has developed an Interim Specific Ground Water Standard 

of 100 μg/L to address its detection in ground water at a contaminated site. This standard is based 

on a human health criterion of 100 μg/L and a PQL of 0.5 μg/L (NJDEP, 2008c). The PQL is 

based on multiplication of the detection limit (0.09 μg/L) by a factor of 5 in USEPA 200.8, Metals 

in Waters by ICP/MS.

Response: EPA appreciates your support and has included cobalt on the UCMR 3 Assessment 

Monitoring list. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34400 Strontium Page 194 of 401

Comment Code: 34400 Strontium

Individual Comments

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31599

Comment Code: 34400

Comment: * EPA’s drinking water guideline for strontium over a lifetime (

http://water.epa.gov/action/advisories/drinking/drinking_index.cfm) and the 2001 Hazardous 

Substances Database (Hazardous Substances Data Base. National Library of Medicine 

[http://toxnet.nlm.nih.gov]) cite a Health Reference Level (HRL) of 4 mg/L (4000 ug/L). 

Therefore it seems that the MRL of 0.03 μg/L for this contaminant is too low to be relevant to 

either the occurrence or health reference level.

AMWA has additional detailed comments about the analytical methods for the proposed UCMR-3 

list as well as the sampling locations, as described below.

Response: It should be noted that new health effects data may become available in the future that 

result in a lower HRL. Therefore, since an HRL is not a fixed value, but rather a value that varies 

based on new studies or revised evaluation procedures, EPA has determined that it is prudent to 

base UCMR MRLs on a scientifically sound determination of laboratory capabilities, rather than a 

potentially transient HRL value. Basing the MRLs solely on the current HRL values, when lower 

MRLs are analytically achievable without significant cost differences, would not be an efficient use 

of the limited resources available for water systems and laboratories that participate in unregulated 

contaminant monitoring. 

Commenter Name: Eddy So 

Commenter Organization: San Francisco Public Utilities Commission

Letter ID: 0082

Comment ID: 31704

Comment Code: 34400

Other EPA Comment Codes and Descriptions: 38100 Chromium-6; 38200 Total Chromium

Comment: Inclusion of Hexavalent Chromium in UCMR3 We support the inclusion of hexavalent 

chromium as one of the 30 contaminants for Assessment monitoring in the final UCMR3. We also 

believe that concurrent monitoring of total chromium could provide crucial information regarding 

the relative occurrence of these contaminants and help determine in the future whether utilities and 

regulatory agencies should continue the use of total chromium as a surrogate for hexavalent

chromium. However, we suggest EPA describe in the final UCMR3 what approach, if chosen, 

would be used to characterize the relationship of total chromium as the hexavalent chromium 

surrogate.

If something needs to be removed from the proposed UCMR3 list to make room for hexavalent 

chromium, we suggest excluding strontium for the following reasons: 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

34400 Strontium Page 195 of 401

- Based on available information from World Health Organization[FN1: World Health 

Organization: Concise International Chemical Assessment Document 77: Strontium and Strontium 

Compounds, 2010], there are data on strontium concentrations at many points in the public water 

system, including entry, various points in the treatment and distribution systems, and finished 

drinking water, and

- It is not a major additive (as compared with molybdenum and vanadium) to alloy steel, so the 

release of strontium is not expected to be more significant than the others. Thus, the inclusion of 

strontium in this round of UCMR3 is less justified than hexavalent chromium and the other three 

inorganic contaminants. 

Regards,

- Eddy So, P.E.(Civil), P.E.(Mech) Regulatory Workgroup Supervisor Water Quality Division San 

Francisco Public Utilities Commission 1657 Rollins Road Burlingame, CA 94010 Tel: 650-652-3115

Email: eso@sfwater.org

Response: EPA believes that monitoring for strontium is justified. While strontium has a relatively 

high health risk level of 4,200 μg/L, it has previously been detected at high percentages (>90%) in a 

number of water occurrence studies, with upper levels of quantitation at concentrations far 

exceeding this health level. Chromium-6 (hexavalent chromium) and total chromium have been 

added to the list of contaminants to be monitored. In addition, sec-butylbenzene and npropylbenzene have been removed from the list of contaminants to be monitored. Please see 

response to comment code 38100 Chromium-6.

Commenter Name: Anonymous 

Commenter Organization:

Letter ID: 0039

Comment ID: 31736

Comment Code: 34400

Comment: Strontium is on the list and I question why. USGS has thousands of analysis along with 

probably all 50,000 public water utilties. Sr is easily measured even at ultra low concentrations, there 

is a wealth of data as it is listed on all the consumer confidence reports I have seen (typically 

included in major ion analysis by ICP-OES or ICP-MS. The extra couple thousand analysis by 

inclusion of Sr in UCMR-3 is essentially a waste of taxpayer money.

Response: EPA agrees that strontium is easily measured with reporting concentrations below the 

currently available levels of health concern. Also, EPA agrees that there is a considerable quantity of 

data available on the occurrence of strontium in water. However, there has not been any recent 

nationwide occurrence survey of strontium in drinking water (the latest is the National Inorganics 

and Radionuclides Survey conducted in 1984 - 1986). Collection of more recent drinking water 

occurrence data will greatly help EPA determine if there is a need to regulate strontium in drinking 

water, and if so, at what concentration.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

35010 EPA Method 300.1 - Chlorate Page 196 of 401

Comment Code: 35010 EPA Method 300.1 - Chlorate

Individual Comments

Commenter Name: Dennis O'Sullivan

Commenter Organization: DoD Safe Drinking Water Act Services Steering Committee

Letter ID: 0048

Comment ID: 31609

Comment Code: 35010

Comment: Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 300.1: 15; 19; 21

Para#/ Line# (Methods documents): METHOD 300.1: 9.3.2.2; 9.4.3.2; 10.5.1 Comment 

Classification C/M/S/A: S

Comment: Sliding scale of acceptance criteria over the quantitation range introduces additional 

uncertainty to the analysis.

Rationale: The control limits used to evaluate the LFB are not consistent over the entire quantitation 

range. It cannot be determined at what point the uncertainty changes in the calibration. It is 

recommended that the same acceptance criteria be used for each LFB, regardless of the 

concentration. This same comment applies to the evaluation of RPDs of the duplicate analysis 

(Section 9.4.3.2), calibration verification recoveries (Section 10.5.1). Sections 9.3.2.2 and 9.3.2.3 have 

typos. The "LRB" acronym is used instead of the "LFB" acronym.

Response: EPA has provided a consistent definition throughout the UCMR 3 for the Minimum 

Reporting Limit (MRL) as the concentration that can be monitored within 50-150 % of the true 

value. The precision and accuracy of chemical analysis is a function of the concentration being 

measured, therefore, it is valid to specify data quality objectives that take this into account and 

change the data quality requirements to a level consistent with the performance of each method for 

concentrations exceeding the MRL. 

These typos are corrected in an April 27, 1999 errata to Method 300.1. This errata version will be 

loaded to the docket. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

35030 SM 4110D (1997) - Chlorate Page 197 of 401

Comment Code: 35030 SM 4110D (1997) - Chlorate

Individual Comments

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31755

Comment Code: 35030

Comment: 18. The voluntary consensus methods SM4110D and SM3125 being cited by EPA 

should be the most recent versions (2000 and 2009 respectively) rather than older versions (1997). 

Additionally the citations should include the relevant Standard Methods current QA/QC sections 

4020 (2010) and 3020 (2009), which are an inherent part of the methods. 

Response: Please see response to comment code 34030 SM 3125 (1997) - Metals.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31756

Comment Code: 35030

Comment: 19. EPA has cited SM4110D for chlorate monitoring, but the lab approval manual 

requires a modification to the method to include the DCAA surrogate found in EPA method 300.1. 

We recognize the value of standard surrogate for most methods to demonstrate that a sample does 

not have matrix suppression. However the nature of IC is such that we believe it brings limited 

value, especially when the surrogate being used is a probable human carcinogen. The acceptance 

limits for DCAA in the method are 90-115%, which reflects the possible presence of DCAA in

samples. DCAA does not necessarily mimic the behavior of the target analyte, chlorate. In 

conducting analysis using EPA method 300.1 for nearly 10 years, we have seen only a handful of 

cases where the surrogate recovery has been outside of these limits. In those cases, a reanalysis with 

acceptable surrogate recoveries did not result in a change in the concentration of the target analyte. 

Thus we encourage EPA to also allow the use of method 300.0 which does not require the use of 

DCAA and to also allow the use of 4110D as written (without the DCAA). We DO recommend the 

use of the 75%-125% MRL acceptance limits from Method 300.1 as opposed to the 50%-150% 

acceptance limits from Method 300.0. At the MRL of 20 ug.L not only are these limits easily ts

achievable, but act as a better measure of the state of the instrument than relying on the surrogate. 

Response: The surrogate is used as a control measure to verify proper injection volume and 

instrument performance thus ensuring the quality of the resultant monitoring data. An alternate 

surrogate other than DCA may be selected by the laboratory, provided that surrogate is an anion 

that yields effective performance data and is not measured in the field sample at concentrations 

exceeding 5% of the fortified concentration. Laboratory analysts must have a definitive measure by 

which to evaluate the analytical efficacy of the separator column since the analytical column's 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

35030 SM 4110D (1997) - Chlorate Page 198 of 401

stationary phase will degrade over time based on the number of samples analyzed and the dynamic 

character of those previously analyzed sample matrices. Quality-conscious laboratories will adopt the 

procedure defined in Method 300.1, section 9.3.3, and monitor both the gradual shift in the 

surrogate retention time as the column ages and the Peak Gaussian Factor evaluating the symmetry 

of the surrogate chromatographic elution. Meeting this surrogate performance criterion, along with 

passing all required quality control in the method, demonstrates laboratory performance is in control 

and assures the generation of high quality data. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32081

Comment Code: 35030

Other EPA Comment Codes and Descriptions: 34030 SM 3125 (1997) - Metals

Comment: EPA should also cite the most recent version of Standard Methods,whether citing 

4110D or 3125, so as to include more stringent quality control than is reflected in older versions of 

these methods. Additional quality control is consistent with EPA’s desire for high quality UCMR3 

data.

Response: Regarding comments about EPA's use of outdated alternate methods cited in the 

proposed rule, EPA agrees that outdated versions of SM4110D and SM3125 were cited in the 

proposal. These have been corrected to the 2005 versions of both methods. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32104

Comment Code: 35030

Comment: 15.EPA was unable to identify methods from voluntary consensus method 

organizations that were applicable to the monitoring required. [except] for the analysis of vanadium, 

molybdenum, cobalt, strontium and chlorate...EPA..., invites the public to identify potentiallyapplicable voluntary consensus standards and to explain why such standards should be used in this 

regulation. 

As noted previously EPA should include Standard Method 4110D (as written) for monitoring of 

chlorate (SM 4110D is equivalent to EPA 300.0), and revise the current reference for Standard 

Method 3125 and 4110D to the latest revision of that method.

Response: Please see response to comment code 34030 SM 3125 (1997) - Metals.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

35040 Other Methods - Chlorate Page 199 of 401

Comment Code: 35040 Other Methods - Chlorate

Individual Comments

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32082

Comment Code: 35040

Comment: AWWA recommends the expansion of the list of allowed methods in UCMR3. EPA 

should recognize the use of: 

1. EPA Method 300.0 for monitoring of chlorate, and 

2. Standard Method 4110D as written, for monitoring of chlorate (SM 4110D is equivalent to EPA 

300.0). [FN13: AWWA recognizes that EPA Method 300.0 does not include the use of the DCAA 

surrogate, but neither does the approved Standard Method 4110D. We note that in the lab approval 

manual EPA mandates the use of the surrogate for Standard Method 4110D. The value of the 

surrogate is to ensure that a sample is truly injected into the instrument. Considering that many 

other SDWA inorganics methods have no requirement for a surrogate, and because the surrogate is 

a haloacetic acid (DCAA) which does occur in many water systems, we question whether the use of 

the surrogate is really necessary.]

Response: The surrogate is used as a control measure to verify proper injection volume and 

instrument performance thus ensuring the quality of the resultant monitoring data. An alternate 

surrogate other than DCA may be selected by the laboratory, provided that surrogate is an anion 

that yields effective performance data and is not measured in the field sample at concentrations 

exceeding 5% of the fortified concentration. Laboratory analysts must have a definitive measure by 

which to evaluate the analytical efficacy of the separator column since the analytical column's 

stationary phase will degrade over time based on the number of samples analyzed and the dynamic 

character of those previously analyzed sample matrices. Quality-conscious laboratories will adopt the 

procedure defined in Method 300.1, section 9.3.3, and monitor both the gradual shift in the 

surrogate retention time as the column ages and the Peak Gaussian Factor evaluating the symmetry 

of the surrogate chromatographic elution. Meeting this surrogate performance criterion, along with 

passing all required quality control in the method, demonstrates laboratory performance is in control 

and assures the generation of high quality data. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

35050 Sampling Location - Chlorate Page 200 of 401

Comment Code: 35050 Sampling Location - Chlorate

Summary Response to Comments on Sampling Location - Chlorate: Please see response to 

comment code 34050 Sampling Locations - Metals.

Individual Comments

Commenter Name: David Chang 

Commenter Organization: Golden State Water Company (GSWC)

Letter ID: 0054

Comment ID: 31631

Comment Code: 35050

Comment: * GSWC is also in agreement with monitoring for chlorate at maximum retention time 

points in the distribution system (DSMRT), to determine if these constituents are precipitating out 

of solution subsequent to chlorination and accumulating in distribution mains. 

Response: EPA appreciates your support and has included DSMRT sampling. 

Commenter Name: Phillip W. Holderness 

Commenter Organization: California-Nevada Section, American Water Works Association (CANV AWWA)

Letter ID: 0055

Comment ID: 31637

Comment Code: 35050

Comment: * CA-NV AWWA is also in agreement with monitoring for chlorate at maximum 

retention time points in the distribution system (DSMRT), to determine if these constituents are 

precipitating out of solution subsequent to chlorination and accumulating in distribution mains. 

Response: EPA appreciates your support and has included DSMRT sampling. 

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31685

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: EPA is requesting comment on DSMRT, distribution system maximum residence time,

sampling for the metals and chlorate. [...] NMED Comment

NMED has no comment on the DSMRT sampling for metals and chlorate. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

35050 Sampling Location - Chlorate Page 201 of 401

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Deborah H. Metz 

Commenter Organization: Greater Cincinnati Water Works (GCWW)

Letter ID: 0085

Comment ID: 31707

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: 2. Distribution system monitoring 

a. Use of Disinfection By-products Rule's (DBPR) Distribution System Maximum Residence Time 

(DSMRT) locations for metals may not be appropriate. Additionally, Entry Point to the Distribution 

System (EPTDS) as wells as DSMRT sampling locations may not be appropriate for chlorate. We 

recommend using a representative location or an average Distribution System Residence Time 

(DSRT) location for such sampling. These average residence time sites were identified by systems 

that performed lOSE under the Stage 2 D/DBP Rule. This is significant in the context of EPA's 

health risk levels of 1 in 10,000. Normally, maximum residence times are at the distil end of a 

distribution system and may represent the absolute worst location, and population served beyond 

that point is normally minimal.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31723

Comment Code: 35050

Comment: 6. Chlorate Monitoring. EPA proposes all water agencies subject to UCMR3 monitor 

chlorate at the Distribution System Maximum Residence Time (DSMRT) sample location. CVWD 

believes monitoring at the DSMRT would only be justified for water agencies adding sodium 

hypochlorite to boost residual chlorine levels within the distribution system. Chlorate formation 

occurs during the storage of sodium hypochlorite solutions and production of chlorine dioxide and 

no measurable chlorate formation will occur when these chemicals are diluted with drinking water 

within the distribution system. Chlorate monitoring at the DSMRT location is not warranted for 

water agencies that do not add sodium hypochlorite or chlorine dioxide within the distribution 

system after the entry point.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31765
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35050 Sampling Location - Chlorate Page 202 of 401

Comment Code: 35050

Comment: 6. Chlorate Monitoring. EPA proposes all water agencies subject to UCMR3 monitor 

chlorate at the Distribution System Maximum Residence Time (DSMRT) sample location. 

WESTCAS believes monitoring at the DSMRT would only be justified for water agencies adding 

sodium hypochlorite to boost residual chlorine levels within the distribution system. Chlorate 

formation occurs during the storage of sodium hypochlorite solutions and production of chlorine 

dioxide and no measurable chlorate formation will occur when these chemicals are diluted with

drinking water within the distribution system. Chlorate monitoring at the DSMRT location is not 

warranted for water agencies that do not add sodium hypochlorite or chlorine dioxide within the 

distribution system after the entry point. 

Response: Please see response to comment code 34050 Sampling Locations - Metals.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31779

Comment Code: 35050

Comment: 13. Chlorate samples at distribution system max residence time location AMWA

tentatively supports EPA’s proposal to monitor for chlorate at the EPDS as well as DSMRT. 

AMWA agrees with EPA’s rationale that the additional information will help the agency assess 

chlorate results, as long as the recommendations expressed in these comments under Comment 4 

are incorporated. EPA states its purpose for including chlorate DSMRT locations is to determine 

whether chlorate increases in the distribution system and AMWA agrees that having the data about 

disinfectant type is needed in order to make an informed study of the results. However, as noted in 

our comments under Comment 4, the collection of the disinfection data must be done in a manner 

more detailed and specific than EPA has proposed. 

Response: EPA appreciates your support of EPTDS and DSMRT sampling. EPA has clarified the 

requirement for reporting disinfection type. 

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31798

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 38130 Sampling Location - Chromium-6 

Comment: E. Metals samples at distribution system maximum residence time location (76 FR

11723)

DEP believes that the only compounds within UCMR-3 that should be analyzed at DSMART are 

those constituents that are either disinfection byproducts or metals that are more toxic in the 
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oxidized state. Of the UCMR list metals, DEP would support assessing Cr+VI at DSMRT, if 

included in UCMR-3, and chlorate as a disinfection byproduct.

Response: Please see response to comment codes 38130 Sampling Location - Chromium-6 and 

34010 EPA Method 200.8 Rev 5.4 - Metals.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31817

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: Lastly, collected distribution system maximum residence time (DSMRT) data for metals 

and chlorate will not likely be solely dependent on water source and treatment, but may be greatly 

influenced by PWS infrastructure and operations. At smaller PWSs, water operators sometimes lack 

knowledge of distribution hydraulics, resulting in site choices which may not represent the oldest 

water. Nevertheless, the DSMRT sampling adds exposure information to the collected data.

The Minnesota Department of Health appreciates the opportunity to review and comment and 

hopes for continued discussion in order to most efficiently implement this regulation. If you have 

questions, please contact Mr. David Rindal, Community Public Water Supply Unit, Drinking Water 

Protection Section, at 651/201-4660.

Sincerely,

Randy Ellingboe, P.E., Program Manager Drinking Water Protection Section Environmental Health 

Division P.O. Box 64975 St. Paul, Minnesota 55164-0975

Response: EPA appreciates your comment and has included DSMRT sampling. We believe that 

operators understand their systems sufficiently to pick a sampling location that represents some of 

the oldest water, which will satisfy the needs of this rule.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ)

Letter ID: 0087

Comment ID: 31823

Comment Code: 35050

Comment: Chlorate 

The EPA is requesting comment on distribution system maximum residence time sampling (MRT) 

for the metals and chlorate. Chlorate is proposed to be monitored at both the EPs and the MRT to 

determine the magnitude of chlorate increases in the distribution system. The metals are monitored 

at both locations to assess any potential contribution from the distribution system. 
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The TCEQ generally supports advancement of the science related to inorganic contaminant 

variation in distribution systems. However, the TCEQ is not convinced there is a need to prioritize 

chlorate monitoring in distribution systems.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31828

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: Sampling location

Under40 CFR 141.40(a)(4)(i)(C), the EPA requires systems to collect metal and chlorate samples at 

distribution system MRT sampling locations. If these locations are not defined, EPA requires PWS 

to collect samples at locations that best represents the maximum residence time in the distribution 

system.

The TCEQ notes that the EPA's sample tracking protocols under UCMR 2 inadequately tracked 

distribution system sites, and recommends that the EPA revisit its quality control review processes 

as they relate to distribution system sample locations.

Response: For UCMR 2, the Texas Commission on Environmental Quality selected all of the 

distribution sampling locations for the State of Texas. EPA is unaware of any issue related to 

tracking of distribution samples in UCMR 2. Please see response to comment code 34050 Sampling 

Location - Metals.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31831

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: Maximum residence time sampling (MRT)

In addition to EP monitoring, EPA proposes to sample the four metals-cobalt, molybdenum, 

vanadium, and strontium-as well as chlorate, at one distribution system MRT sampling point per 

treatment plant If the system is subject to the Stage 2 Disinfectants and Disinfection Byproducts 

Rule (DBP2), then samples for the metals and chlorate must be collected at the MRT sampling 

location identified for that rule. 
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35050 Sampling Location - Chlorate Page 205 of 401

The TCEQ notes that there may be systems just starting DBP2 sampling during the time period of 

UCMR3 sampling and recommends that the EPA provide flexibility to these systems in order to 

spread the cost impact out over the greatest time period possible. 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31835

Comment Code: 35050

Comment: Chlorate and Metals Monitoring at DSMRT 

EPA is proposing that chlorate, and the metals -cobalt, molybdenum, vanadium and strontium be 

monitored at the EPTDS and DSMRT locations (FR page 11717 Exhibit 2, 11723, 11725, 141.40 

(a)(3), Table 1, and 141.40 (a)(4}(i}(c)). EPA does not provide the basis for requiring testing for 

chlorate and the metals at the DSMRT location. 

Riverside does not support monitoring for chlorate or the four metals at the DSMRT location. In 

the UCMR preamble, EPA only provides two descriptive sentences stating that chlorate and the 

four metals will be monitored at the DSMRT location as shown above (excerpt from FR page 

11723). EPA does not provide a firm scientific foundation that chlorate "increases in the 

distribution system," that is, increasing in concentration from the point of entry to a location 

downstream that best represents the maximum residence time in the distribution system. There are 

no scientific studies or research projects referenced in the proposed UCMR3 document that show 

chlorate increases in the distribution system are due to disinfectant oxidants, thus warranting 

DSMRT monitoring in UCMR3. If DSMRT chlorate monitoring is warranted, EPA needs to 

provide the basis and criteria that triggers the need for at testing at the DSMRT location. 

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31850

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: 6.0 Chlorate and Metals Monitoring at DSMRT 

EPA is proposing that chlorate and the four metals, cobalt, molybdenum, vanadium, and strontium 

be monitored at the entry point to the distribution system (EPTDS) and the distribution system 

maximum residence time (DSMRT). EPA is requesting comment on the DSMRT sampling for the 

metals and chlorate.
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6.1 Chlorate and Metals DSMRT Monitoring 

EPA is proposing that chlorate, and the metals - cobalt, molybdenum, vanadium and strontium be 

monitored at the EPTDS and DSMRT locations (FR page 11717 Exhibit 2, 11723, 11725, 141.40 

(a)(3) Table1, and 141.40 (a)(4)(i)(c)). EPA does not provide the basis for requiring testing for 

chlorate and the metals at the DSMRT location. The only discussion provided for the DSMRT 

monitoring appears in the preamble as shown by the following excerpts (FR page 11723):

* "EPA is proposing revisions to UCMR that would require systems to report all data elements with 

each sample (including Data Element 6 (Disinfectant Type)) since Assessment Monitoring within 

the distribution system is proposed and since the information on disinfectant type would be useful 

in the Agency’s evaluation of results for chlorate and the metals on List 1 - Assessment 

Monitoring...."

* "Chlorate is being monitored at both the EPTDS and the DSMRT to determine the magnitude of 

chlorate increases in the distribution system. The metals are monitored at both locations to assess 

any potential contribution from the distribution system." 

Under UCMR2, the nitrosamines were monitored at the EPTDS and DSMRT locations because of 

the potential formation of nitrosamine species (e.g., N- nitrosodimethylamine, NDMA) as a 

disinfection by-product. Because of the close relationship of potential nitrosamine species formation 

and disinfectant oxidants, collecting information on the type of disinfectant is reasonable. However, 

EPA does not provide the reasoning for requiring information on the type of disinfectant and levels 

of chlorate or the metals detected at either the EPTDS or DSMRT locations. EPA needs to provide 

the rationale for requesting disinfectant type specific for chlorate and the metals relative to the 

detection of these analytes.

OCWD does not support monitoring for chlorate or the four metals at the DSMRT location. In the 

preamble, EPA only provides two descriptive sentences stating that chlorate and the four metals will 

be monitored at the DSMRT location as shown above (excerpt from FR page 11723). EPA does not 

provide a firm scientific foundation that chlorate "increases in the distribution system," that is, 

increasing in concentration from the point of entry to a location downstream that best represents 

the maximum residence time in the distribution system. There are no scientific studies or research 

projects referenced in the proposed UCMR3 document that show chlorate increases in the 

distribution system are due to disinfectant oxidants (as was provided for NDMA monitoring under 

UCMR2), thus warranting DSMRT monitoring in UCMR3. If DSMRT chlorate monitoring is 

warranted, EPA needs to provide the basis and criteria that triggers the need for testing at the 

DSMRT location. 

Similarly, OCWD does not support the monitoring for the four metals at the DSMRT location and 

recommends that this requirement be removed from UCMR3. The proposed UCMR3 document 

does not discuss the scientific reasoning to include DSMRT monitoring for the metals. The 

preamble only states that DSMRT monitoring is listed "to assess any potential contribution from the 

distribution system. "A key monitoring objective of the UCMR3 program is to collect occurrence 

data of unregulated contaminants in treated drinking water at the EPTDS which is primarily 

representative of the source water and not contributions from the distribution system. The 

information collected for metals occurrence at DSMRT locations will be system specific and will 

require additional information on the infrastructure, source water quality, flow dynamics, and other 
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35050 Sampling Location - Chlorate Page 207 of 401

physical and chemical parameters to place distribution-source metals data in perspective. EPA and 

the Water Research Foundation have developed a priority list of research and data needs focused on 

the distribution system. Formed in January 2009, the Distribution System Research and Information 

Collection Partnership, not UCMR3, is the appropriate forum to address the occurrence of the four 

metals in the distribution system. The Partnership has identified "accumulation and release of

contaminants from distribution scales and sediment" as an issue to be addressed through research 

and information collection activities.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31869

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: Currently, the proposed sampling locations include entry point to the distribution 

system (EPTDS) and, for metals and chlorate, distribution system mean residence time (DSMRT). 

Expanding the sampling locations to include the source prior to treatment would provide 

information on the effects of treatment on contaminants. This additional sampling will have added 

analytical costs, but the additional information gathered should be very valuable. There should be 

little additional costs for sample collection and program administration due to collection of 

untreated source samples. These two changes would expand the utility of the UCMR process to help 

identify the impact of treatment on contaminant occurrence. The treatment processes currently used 

in SDWIS could be used as a guide to create a list of treatment processes for selection under data 

element 6.

Response: Congress designed the UCMR program to monitor for unregulated contaminants in the 

nation's drinking water. As a result, EPA’s priority is occurrence at the EPTDS and within the 

distribution system where exposure risks are greatest.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31893

Comment Code: 35050

Other EPA Comment Codes and Descriptions: 34050 Sampling Location - Metals

Comment: 6.0 Chlorate and Metals Monitoring at DSMRT 

EPA is proposing that chlorate and the four metals, cobalt, molybdenum, vanadium, and strontium 

be monitored at the entry point to the distribution system (EPTDS) and the distribution system 

maximum residence time (DSMRT). EPA is requesting comment on the DSMRT sampling for the 

metals and chlorate.
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6.1 Chlorate and Metals DSMRT Monitoring 

EPA is proposing that chlorate, and the metals - cobalt, molybdenum, vanadium and strontium be 

monitored at the EPTDS and DSMRT locations (FR page 11717 Exhibit 2, 11723, 11725, 141.40 

(a)(3) Table1, and 141.40 (a)(4)(i)(c)). EPA does not provide the basis for requiring testing for 

chlorate and the metals at the DSMRT location. The only discussion provided for the DSMRT 

monitoring appears in the preamble as shown by the following excerpts (FR page 11723):

*"EPA is proposing revisions to UCMR that would require systems to report all data elements with 

each sample (including Data Element 6 (Disinfectant Type)) since Assessment Monitoring within 

the distribution system is proposed and since the information on disinfectant type would be useful 

in the Agency’s evaluation of results for chlorate and the metals on List 1-Assessment Monitoring..." 

*"Chlorate is being monitored at both the EPTDS and the DSMRT to determine the magnitude of 

chlorate increases in the distribution system. The metals are monitored at both locations to assess 

any potential contribution from the distribution system." 

Under UCMR2, the nitrosamines were monitored at the EPTDS and DSMRT locations because of 

the potential formation of nitrosamine species (e.g., Nnitrosodimethylamine, NDMA) as a 

disinfection by-product. Because of the close relationship of potential nitrosamine species formation 

and disinfectant oxidants, collecting information on the type of disinfectant is reasonable. However, 

EPA does not provide the reasoning for requiring information on the type of disinfectant and levels 

of chlorate or the metals detected at either the EPTDS or DSMRT locations. EPA needs to provide 

the rationale for requesting disinfectant type specific for chlorate and the metals relative to the 

detection of these analytes.

ACWA does not support monitoring for chlorate or the four metals at the DSMRT location. In the 

preamble, EPA only provides two descriptive sentences stating that chlorate and the four metals will 

be monitored at the DSMRT location as shown above (excerpt from FR page 11723). EPA does not 

provide a firm scientific foundation that chlorate "increases in the distribution system," that is,

increasing in concentration from the point of entry to a location downstream that best represents 

the maximum residence time in the distribution system. There are no scientific studies or research 

projects referenced in the proposed UCMR3 document that show chlorate increases in the 

distribution system are due to disinfectant oxidants, thus warranting DSMRT monitoring in 

UCMR3. If DSMRT chlorate monitoring is warranted, EPA needs to provide the basis and criteria 

that triggers the need for testing at the DSMRT location. 

Similarly, ACWA does not support the monitoring for the four metals at the DSMRT location and 

recommends that this requirement be removed from UCMR3. The proposed UCMR3 document 

does not discuss the scientific reasoning to include DSMRT monitoring for the metals. The 

preamble only states that DSMRT monitoring is listed "to assess any potential contribution from the 

distribution system." A key monitoring objective of the UCMR3 program is to collect occurrence 

data of unregulated contaminants in treated drinking water at the EPTDS which is primarily 

representative of the source water and not contributions from the distribution system. The 

information collected for metals occurrence at DSMRT locations will be system specific and will 

require additional information on the infrastructure, source water quality, flow dynamics, and other 

physical and chemical parameters to place distribution-source metals data in perspective. EPA and 

the Water Research Foundation have developed a priority list of research and data needs focused on 
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35050 Sampling Location - Chlorate Page 209 of 401

the distribution system. Formed in January 2009, the Distribution System Research and Information 

Collection Partnership, not UCMR3, is the appropriate forum to address the occurrence of the four 

metals in the distribution system. The Partnership has identified "accumulation and release of 

contaminants from distribution scales and sediment" as an issue to be addressed through research 

and information collection activities.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32091

Comment Code: 35050

Comment: AWWA does not support the monitoring for chlorate at the DSMRT locations and 

EPA should remove this requirement from the final UCMR3. The only instances when both 

EPTDS and DSMRT samples are appropriate is when booster disinfection or breakpoint 

chlorination occurs in the distribution system. In these instances, sodium hypochlorite might be 

used and contribute chlorate in the distribution system beyond the EPTDS. Neither instance 

represents a typical situation, but neither are these practices rare. EPA might consider requiring 

representative samples downstream from where these practices do occur rather than for all water

systems.

Response: Please see response to comment code 34050 Sampling Location - Metals.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080

Comment ID: 32102

Comment Code: 35050

Comment: AWWA does not support the monitoring for chlorate at the DSMRT locations and 

EPA should remove this requirement from the final UCMR3. The only instance when both an 

EPTDS and DSMRT sample is appropriate is when there are either (1) booster disinfection or (2) 

breakpoint chlorination occurring in the distribution system. In these instances sodium hypochlorite 

might be used and contribute chlorate in the distribution system beyond the EPTDS. Neither 

instance represents a typical situation, but neither are these practices rare. EPA might consider 

requiring representative samples downstream from where these practices do occur. 

Response: Please see response to comment code 34050 Sampling Location - Metals.
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35100 Chlorate Page 210 of 401

Comment Code: 35100 Chlorate

Individual Comments

Commenter Name: Therese M. Cirone

Commenter Organization: The Chlorine Institute

Letter ID: 0053

Comment ID: 31626

Comment Code: 35100

Other EPA Comment Codes and Descriptions: 40000 Minimum Reporting Level 

Determination/LCMRLs

Comment: Chlorate Monitoring - MRL 20 ug/l

EPA is proposing that the MRL for chlorate be 20ug/l. Given that chlorates have not been found to 

be carcinogenic, mutagenic or genotoxic and no reproductive or developmental toxicity has been 

observed in studies, it would appear this MRL is artificially set by at least an order of magnitude 

below its potential health risk level. The Chlorine Institute is concerned that this could potentially 

generate data that may be subject to misinterpretation because of a notion that any positive values 

are potentially considered significant. Given that the purpose of UCMR monitoring is to determine 

the occurrence in the range of concentrations relevant to public health protection, EPA should set 

appropriate minimum reporting levels that reflect the level of potential health relevance.

The Chlorine Institute strongly supports EPA’s efforts to continually improve drinking water 

programs and to protect the public health. We thank EPA for this opportunity to provide input and 

ask that our comments be considered in development of the final rule. 

Sincerely, Therese M Cirone Vice President Health, Environment, Safety and Security

Response: Please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.
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36000 Perfluorinated Compounds (PFCs) Page 211 of 401

Comment Code: 36000 Perfluorinated Compounds (PFCs)

Summary Response to Comments on Perfluorinated Compounds (PFCs): EPA believes that 

monitoring for perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), 

perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), perfluorononanoic acid (PFNA), 

and perfluorobutanesulfonic acid (PFBS) is justified based on available toxicological and occurrence 

data. EPA has described its rationale for including these contaminants in the proposed rule on 

March 3, 2011 (76 FR 11713). For example, the Centers for Disease Control and Prevention (CDC) 

Fourth National Report on Human Exposure to Environmental Chemicals, 2009, reported the 

following concentrations of PFCs in human blood samples: 

- For PFHxS CDCs 95th Percentile Conc.: 8.30 μg/L for 2,094 serum samples (2003-2004); detects 

in 98.3% of samples

- For PFHpA CDCs 95th Percentile Conc.: 0.400 μg/L for 2,094 serum samples (2003-2004); 

detects in 6.2% of samples

- For PFNA CDCs 95th Percentile Conc.: 3.20 μg/L for 2,094 serum samples (2003-2004); detects 

in 98.8% of samples

The presence of these PFCs in human blood at these concentrations and at these frequencies 

supports EPA's decision to monitor for them in UCMR 3. Furthermore, perfluorinated compounds 

of current interest in the environment are primarily based on an eight carbon structure. Due to 

health concerns with these C8 perfluorinated compounds (PFOS, PFOA, etc.) the industry has been 

moving to the use of perfluorinated compounds with a four carbon structure. One of the primary 

C4 based perflourocarbons being used is perfluorobutanesulonic acid (PFBS). Therefore, EPA 

believes that it is important to obtain occurrence data on PFBS in drinking water. 

Chromium-6 (hexavalent chromium) and total chromium have been added to the list of 

contaminants to be monitored. In addition, sec-butylbenzene and n-propylbenzene have been 

removed from the list of contaminants to be monitored. Please see response to comment code 

38100 for further discussion about Chromium-6.

Individual Comments

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31620

Comment Code: 36000

Comment: To make room for Chromium-6, CTDPH suggests removing one of the following 

contaminants: 

4) Perfluorinated compounds: obviously there are several compounds that are targeted on the 

proposed list, which present a reasonable opportunity to trim one of them off the list and replace it 

with Chromium-6.
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36000 Perfluorinated Compounds (PFCs) Page 212 of 401

Response: Please see response to comment code 36000 Perfluorinated Compounds (PFCs). 

Commenter Name: Larry Zobel

Commenter Organization: 3M Company 

Letter ID: 0063

Comment ID: 31662

Comment Code: 36000

Comment: May 2, 2011 Water Docket U.S. Environmental Protection Agency 1200 Pennsylvania 

Avenue, N. W. Washington, D.C. 20460

Re: Docket No. OW-2009-0090

Ladies and Gentlemen:

3M Company ("3M") appreciates the opportunity to submit comments on the proposed revisions to 

the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems, 76 Fed 

Reg. 11713 (March 3, 2011). In the notice of proposed rulemaking, EPA has proposed assessment 

monitoring for six perfluoroehemicals ("PFCs"). We offer some general comments on analytical 

issues, and then focus our comments on one particular compound, perfluorobutanesulfonate 

("PFBS").

In our general comments, we urge the agency to correct a flaw in the EPA analytical method for 

PFCs (other than PFOS) that produces results that could be biased either high or low. In addition, 

EPA may wish to evaluate new analytical methods, soon to be published, that couId save costs for 

both EPA and thousands of municipalities.

Response: EPA's Method 537 has been extensively researched, it has been peer reviewed, and has 

been demonstrated in multiple laboratories. EPA is confident that Method 537 will provide high 

quality occurrence data. EPA does not agree that there is a significant flaw in this method.

Commenter Name: Larry Zobel

Commenter Organization: 3M Company 

Letter ID: 0063

Comment ID: 31667

Comment Code: 36000

Comment: 3M appreciates EPA's consideration of these comments. We hope the agency will

carefully review the analytical issues, and will reconsider the inclusion of PFBS and instead focus on 

more important priorities in the UCMR 3 program. 

Respectfully submitted, 

Larry R. Zobel, M.D., MPH Vice President and Medical Director
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January 2012

36000 Perfluorinated Compounds (PFCs) Page 213 of 401

Attachment

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Lieder PH, et al., A two-generation oral gavage reproduction study with potassium 

perfluorobutanesulfonate (K+PFBS) in Sprague-Dawley rats, Toxicology, 2009a, 259: 33.45

Lieder PH, et al., Toxicological evaluation of potassium pcrfluorobutancsulfonate in a 90-day oral 

gavage study with Sprague-Dawley rats, Toxicology, 2009b, 255: 45-52.

Martin JW, et al., Bioconcentration and tissue distribution ofperfluorinated acids in rainbow trout 

(Oncorhynchus mykiss), Environmental Toxicology and Chemistry, 2003, 22: 196-204.
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36000 Perfluorinated Compounds (PFCs) Page 214 of 401

Martin JW, et a1., AnaJytical challenges hamper perfluoroalkyl research. Environ, Sci. Technol., 

2004,38 (13), 248A-255A

Naile JE, et aJ., Standard purity and response factors of perfluorinated compounds, Toxicological & 

Environmental Chemistry, 2010, 92: 1219-1232.

Olsen OW, et al., Decline in perfluorooctanesulfonate and other polyfluoroalkyl chemicals in 

American Red Cross adult blood donors, 2000-2006, Environ Sci Teehnol 2008b, 42: 4989-95.

Olsen OW, et al., A comparison of the pharmacokinetics ofperfluorobutanesulfonate (PFBS) in rats, 

monkeys, and humans, Toxicology 2009, 256: 65-74.

Riddell N, et. al., Branched perfluorooctanc sulfonate isomer quantification and characterization in 

blood Serum Samples by PHLCIESI-MS(IMS), Environ. Sci. Techno!. 2009, 43: 7902-7908.

Wolf, CJ, et al., Activation of Mouse and Human Peroxisome Proliferator- Activated Receptor 

Alpha by Perfluoroalkyl Acids of Different Functional Groups and Chain Lengths, Toxicol.. Sci. 

2008, 106(1): 162-171.

[Attachment: see PDF docket ID EPA-HQ-OW-2009-0090]

Response: Please see response to comment code 36000 Perfluorinated Compounds (PFCs). 

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31682

Comment Code: 36000

Other EPA Comment Codes and Descriptions: 38100 Chromium-6; 38200 Total Chromium

Comment: Page 11718

EPA requests comments on what contaminants should be removed from the list of 30 UCMR 3 

contaminants if chromium6 were added, as well as comments regarding the recommended and 

alternative analytical methods and the appropriate reporting level. EPA also requests comments on 

whether total chromium should also be measured concurrent with chromium6. 

NMED Comment

If chromium6 is added, it should be measured concurrent with total chromium. If chromium6 were 

added, deletion of either perfluorononanoic acid, PFNA; perfluorohexane sulfonic acid, PFHxS; 

perfluoroheptanoic acid, PFH pA; or perfluorobutane sulfonic acid, PFBS, is recommended. The 

other two perfluorinated chemicals should be monitored in New Mexico because they are used in 

fire fighting. New Mexico is subject to fires in periods of drought and high winds. 

Response: Please see response to comment codes 38100 Chromium-6 and 36000 Perfluorinated 

Compounds (PFCs). 
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Commenter Name: Olga Naidenko

Commenter Organization: Environmental Working Group 

Letter ID: 0073

Comment ID: 31688

Comment Code: 36000

Comment: May 2, 2011 Water Docket No. OW-2009-0090 United States Environmental 

Protection Agency 1200 Pennsylvania Avenue, N.W. Washington, DC 20460

Re: Proposed EPA rule on Revisions to the Unregulated Contaminant Monitoring Regulation 

(UCMR 3) for Public Water Systems; 76 FR 11713, March 3, 2011

The Environmental Protection Agency has proposed a nationwide plan to require water utilities to 

test drinking water for 28 contaminants currently unregulated by federal law, including 6 

perfluorinated chemicals, a family of toxic industrial chemicals found widely in consumer products. 

With this letter, Environmental Working Group (EWG) is writing to express its strong support for 

the agency plan, which would help expand knowledge of the scope of drinking water contamination 

nationally and would help state and federal drinking water officials protect water sources from these 

pollutants. 

In addition to perfluorinated chemicals, the Environmental Protection Agency (EPA) proposal also 

includes 7 hormones; 10 synthetic organic compounds, of which 9 are volatile organic compounds; 

and 4 metals (cobalt, strontium, molybdenum, vanadium). The announced testing will constitute the 

third cycle of the unregulated contaminant monitoring of tap water supplies that will apply to all 

public water systems serving more than 10,000 people as well as 800 representative public water 

systems serving 10,000 or fewer people. Monitoring will be done from January 2013 through 

December 2015. EWG comments focus on two points: 

* The inclusion of perfluorinated chemicals on the monitoring list;

* EPA’s request for comments about monitoring for chromium-6 nationwide. 

Details and recommendations are outlined below 

1. The inclusion of perfluorinated chemicals on the monitoring list The agency’s announcement 

represents a major step forward in the government’s efforts to understand and control pollution 

from perfluorochemicals (PFCs), synthetic industrial chemicals that have been used in a wide variety 

of stain-repellent textile coatings, non-stick cookware and water and grease-resistant coatings. This 

contamination, believed to emanate from unregulated industrial emissions, as well as PFC residues 

that wash off consumer goods and leaching of perfluorochemical materials disposed in landfills, 

could pose a serious threat to public health. 

Perfluorochemicals, which do not break down in the environment, pollute drinking water and 

source water in at least 11 states, according to limited investigations by state water agencies, 

academic scientists, businesses and journalists (EWG 2009a). No comprehensive survey has ever 

been conducted to document the extent of PFC pollution in drinking water across the country. 
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EPA’s proposed list includes perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), 

Environmental Working Group comments on EPA’s proposed list of tap water pollutants to be 

tested under Unregulated Contaminant Monitoring Rule perfluorooctane sulfonate (PFOS), 

perfluorohexane sulfonic acid (PFHxS), perfluoroheptanoic acid (PFHpA), perfluorobutane sulfonic 

acid (PFBS).

Response: EPA appreciates your comment and support and has included PFCs on the UCMR 3 

Assessment Monitoring list.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31874

Comment Code: 36000

Comment: Candidates for deletion: 

* Some of the less common perfluorinated compounds could be dropped - perfluorononanoic acid 

(PFNA), perfluorohexane sulfonic acid (PFHxS), perfluoroheptanoic acid (PFH pA), or 

perfluorobutane sulfonic acid (PFBS). The remaining compounds (PFOS and PFOA) are more 

likely to be found and contribute useful data. 

Response: Please see response to comment code 36000 Perfluorinated Compounds (PFCs). 

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31902

Comment Code: 36000

Comment: Perfluorinated Compounds - NJDEP supports the inclusion of perfluorinated chemicals 

(PFCs) in the UCMR3. In detailed comments on the proposed USEPA Contaminant Candidate List 

3 submitted on May 21, 2008 (NJDEP, 2008a), NJDEP urged USEPA to address PFOA in drinking 

water. PFCs in drinking water are of concern because of their potential health effects at low doses, 

persistence in the environment and in the human body, occurrence in drinking water, and because 

exposures to levels commonly occurring in drinking water can contribute substantially to total 

human exposure. 

Response: EPA appreciates your comment and support and has included PFCs on the UCMR 3 

Assessment Monitoring list.

Commenter Name: Gary Buchanan, PhD.

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31904
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Comment Code: 36000

Comment: It is not clear how the six PFCs listed in the proposed UCMR3 were chosen. Analytical 

methods currently used routinely by commercial laboratories include additional PFCs as target 

analytes, and it is desirable to obtain data on these additional PFCs if possible. For example, PFHxA 

is currently being used in commercial products as a replacement for PFOA (DuPont, undated), and 

was quantified in 21% of 33 NJ public water supplies tested in 2009. It is especially relevant to 

obtain data for additional PFCs because USEPA has suggested that they may be regulated as a group 

in the future (USEPA, 2010).

Response: Please see response to comment code 36000 Perfluorinated Compounds (PFCs). 

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31905

Comment Code: 36000

Comment: The MRLs for PFCs in the proposed UCMR3 are 0.02 μg/L for PFOA, 0.04 μg/L for

PFOS, and 0.01 to 0.09 μg/L for the other four PFCs listed. NJDEP’s experience with analysis of 

PFCs in drinking water suggests that lower MRLs are routinely achieved by commercial laboratories. 

In the 2006 and 2009 New Jersey PFC occurrence studies, PFCs were quantified at > 0.004 μg/L 

and 0.005 μg/L, respectively. PFCs were also quantified at similar levels in data reported by New 

Jersey water purveyors as well as in many surface water and drinking water occurrence studies from 

other locations reported in the peer reviewed literature. In the published PFC analytical method, the 

USEPA allows flexibility to utilize a variety of instrument configurations and separation strategies to 

determine the listed parameters in the method. The UCMR3 guidance should be more specific in it 

requirements for a standardized method that can be utilized by the existing laboratory community 

rather than endless variability in single lab configuration. It is important to achieve a more sensitive 

MRL, if possible, because recent toxicology and epidemiology studies suggest that stringent healthbased drinking concentrations may be appropriate for PFOA and some other PFCs. 

Response: EPA's Method 537 has been extensively researched, it has been peer reviewed, and has 

been demonstrated in multiple laboratories. EPA is confident that Method 537 will provide high 

quality occurrence data. Please see response to comment code 36010, EPA Method 537 Rev 1.1 - 

PFCs.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32069

Comment Code: 36000

Comment: [Table 1. Relevant Rationale for Removing Specific Contaminants from UCMR3 [See 

PDF Docket ID: EPA-HQ-OW-2009-0090-0080.1]] Perfluorinated Compounds / EPA 537 / 
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36000 Perfluorinated Compounds (PFCs) Page 218 of 401

PFNA, PFHxS, PFHpA, PFBS / Not on CCL3 - CCL3 is the appropriate process for ranking 

contaminants for data collection. 

Response: Please see response to comment code 36000 Perfluorinated Compounds (PFCs). 
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Comment Code: 36010 EPA Method 537 Rev 1.1 - PFCs

Summary Response to Comments on EPA Method 537 Rev 1.1 - PFCs: EPA Method 537 has 

been extensively researched, it has been peer reviewed, and has been demonstrated in multiple 

laboratories. EPA is confident that Method 537 will provide high quality occurrence data. The data 

quality generated by analytical methods is dependent upon the matrix being analyzed. Wastewater or 

solid waste methods will not be able to match the data quality of the methods designed for the 

analysis of drinking water. Analytical methods developed for the analysis of drinking water, including 

those specifically developed for UCMR 3 have more than sufficient data quality to support the 1/3 

MRL blank designation. Furthermore, the LCMRL/MRL procedure used for UCMR 3 is more 

appropriate because it is based on the simultaneous application of precision and accuracy. Please see 

response to comment code 40000, Minimum Reporting Level Determination/LCMRLs. EPA has 

evaluated the Laboratory Reagent Blanks (LRBs) data and the data easily met the 1/3 MRL 

requirement of the method. Given these data and EPA's experience with the method, maintaining 

the 1/3 MRL requirement should not be an issue for the laboratories. If the laboratories do have any 

such issues it will be apparent during their initial demonstration of capabilities and Method 537 has 

many notes and guidelines contained within it to help users minimize their background 

contamination. The Region IV "Data Validation Standard Operating Producers for Organic 

Analysis" guidelines were developed for superfund contract work and its suggestions as to maximum 

blank levels of analytes are not relevant to drinking water analysis.

Individual Comments

Commenter Name: Dennis O'Sullivan

Commenter Organization: DoD Safe Drinking Water Act Services Steering Committee

Letter ID: 0048

Comment ID: 31612

Comment Code: 36010

Comment: [1] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 537: 17 Para#/ 

Line# (Methods documents): METHOD 537: 8.4 Comment Classification C/M/S/A: S 

Comment: Temperature and hold time requirements vary without explanation. 

Rationale: Why are the shipping and laboratory storage temperature requirements different? Samples 

are to be shipped at less than or equal to 10°C, but yet the laboratory must store the samples once 

received at less than or equal to 6°C.

[2] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 537: 21; 23; 24; 28; 29 

Para#/ Line# (Methods documents): METHOD 537: 9.3.3; 9.3.6.3; 9.3.7.2; 9.3.7.4; 10.2.7; 10.3.3

Comment Classification C/M/S/A: S 

Comment: Sliding scale of acceptance criteria over the quantitation range introduces additional 

uncertainty to the analysis.
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Rationale: Since the low-level LFB concentration is within the quantitation range (1 - 2 times MRL), 

it is not justified to have varying acceptance criteria within the quantitation range. It cannot be 

determined at what point the uncertainty changes from 50 to 30%. It is recommended that the same 

acceptance criteria be used for each LFB, regardless of the concentration. This same comment 

applies to the evaluation of recoveries and RPDs of the field duplicates and LFSM and LFSMDs 

and lowest calibration standard and CCC recoveries.

[3] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 537: 21; 31 Para#/ Line# 

(Methods documents): METHOD 537: 9.3.4.2; 11.5 Comment Classification C/M/S/A: S 

Comment: Internal standard addition process is prohibiting and included as part of the extraction 

process.

Rationale: It is recommended that the internal standard be added to an aliquot of the final sample 

extract, not the entire extract volume. By spiking only a portion of the final extract, the laboratory 

will have the ability to correct for any internal standard spiking errors without reextraction or 

collection of more sample.

[4] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 537: 22 Para#/ Line# 

(Methods documents): METHOD 537: 9.3.6 Comment Classification C/M/S/A: S

Comment: Missing information on native sample correction. 

Rationale: This section does not state at what concentrations it is acceptable to correct LFSM and 

LFSMD concentrations for concentrations found in associated native samples. Is the acceptable 

level less than the MRL, greater than the MRL, or both? 

[5] Page # (FR Notice/ Method): FR: 11718 Exhibit 3-30 / METHOD 537: 33 Para#/ Line# 

(Methods documents): METHOD 537: 12 Comment Classification C/M/S/A: S 

Comment: Missing evaluation criteria.

Rationale: Why doesn't the method require evaluation of the isotope area count ratios for standards, 

samples, and batch QC? This information can provide further confirmation of the analyte's 

presence. The same comment can be made for relative retention times as well.

Response: [1] The extract holding time and temperature are required maximums. Extracts must be 

held at room temperature, for a maximum of 28 days. These requirements are based upon analysis 

performed during analytical methods development. The storage temperature and duration for 

calibration standards is only a recommendation, with an example (two weeks at room temperature). 

The stability of the calibration standards is assured through the quality control requirements of the 

method, whereas, the stability of the extracts can only be assured by the laboratories adherence to 

the extract holding requirements. 
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While it would be optimal to store samples at 6 deg C from collection to analysis, it is impractical. 

Maintaining 6 deg C during transport from the sampling locution to the laboratory is extremely 

difficult. Most commercially available frozen gel packs will not maintain 6 deg C. However, they can 

maintain the required 10 deg C. Therefore, when sample holding times are developed during 

methods development, the samples are maintained at 10 deg C for 48 hours and then the 

temperature is reduced to 6 deg C for the remainder of the holding time testing to more accurately 

represent actual shipping and storage conditions. 

[2] EPA has provided a consistent definition throughout the UCMR 3 methods for the Minimum 

Reporting Limit (MRL) as the concentration that can be monitored within 50 - 150 % of the true 

value. The precision and accuracy of chemical analysis is a function of the concentration being 

measured, therefore, it is valid to specify data quality objectives that take this fact into account and 

change the data quality requirements to a level consistent with the performance of each method for 

concentrations exceeding the MRL. 

[3] Accurate addition of the Internal standard (IS) is dependent on accurately knowing the volume 

of both the amount of IS solution added to the extract and the volume of the extract itself. Section 

11.3 represents the only step in the method where the volume of the final extract is accurately 

known, and therefore, is the only appropriate point for the addition of the IS. 

[4] The commenter is correct. This method does not specify how to handle results below the MRL 

for LFSM or LFSMD, therefore, the same instructions that are provided for the other UCMR 3 

analytical methods will be added to the UCMR 3 laboratory approval manual requiring laboratories 

to extrapolate beyond the MRL for the purposes of calculations involving the LFSM and LFSMD. 

[5] Since this is a tandem mass spectrometry method, additional qualitative evaluations, such as 

comparing isotope ratios, does not provide useful additional qualitative certainty. 

Commenter Name: Larry Zobel

Commenter Organization: 3M Company 

Letter ID: 0063

Comment ID: 31664

Comment Code: 36010

Comment: COMMENTS

PFC Analytical Methods 

We have two comments with regard to the analytical method specified for PFCs: First, the EPA 

reference method has a flaw that can result in biased results for PFCs other than PFOS, and second, 

new, less labor-intensive analytical methods have been developed and will soon be published. EPA 

should explore whether these methods can be adopted sufficiently quickly for use in UCMR 3, given 

that they would result in cost savings to both EPA and thousands of municipalities. 

The proposed rule calls for USEPA Method 537 Rev 1.1 ("Method 537") as the analytical method to 

be applied by laboratories for the measurement of PFCs. However, except with respect to PFOS, 

Method 537 does not sufficiently address the quantification of branched isomers in drinking water 
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samples, which means that analytical results will be biased in the presence of branched isomers. This

problem has been acknowledged in the literature, including in a publication examining branched and 

linear isomers co-authored by researchers from 3M, EPA, CDC, the National Institute of Standards 

and Technology ("NIST"), Environment Canada, and the University of Toronto. (Keller el al. 2010; 

see also Martin el al. 2004, Naile, et al. 2010, De Silva et al. 2006, and references cited in therein.) 

Before collecting data, EPA should ensure that potential bias in the analytical method has been 

addressed. Otherwise, municipalities will incur major expense to generate data that may not be 

reliable.

Specifically, Method 537 does not provide for quantitation of branched structural isomers, except 

for PFOS. For PFOS, the EPA method addressed this concern in detail, and scientific publications 

demonstrate that the procedure in Method 537 for addressing this concern with respect to PFOS is 

effective. (Arsenault, et al., 2008; Riddell, et al., 2009.) With respect to any other PFCs which may 

contain branched isomers, however, Method 537 simply has not addressed the same question. This 

is a particular concern for PFOA, where branched isomers may in some instances be a significant 

portion of the PFOA present in a sample. However, the concern also applies to all of the other 

PFCs proposed for monitoring, as branched isomers may be present. In the absence of a reference

method procedure to quantify structural branched isomers ofPFCs, the potential for significant 

analytical bias in reported data will exist. EPA needs to provide for how to address this bias in the 

method. One way might be to amend Method 537to require the use of newly-available standards. 

For example, a certified PFOA standard including both branched and linear structural isomers has 

become available within the last month. (See Wellington Laboratories Inc., Guelph, Ontario, 

Canada; www.welllabs.com.) 

Response: Please see response to comment code 36010 EPA Method 537 Rev 1.1 - PFCs.

At the time of method development, standards containing linear and branched isomers were not 

available for all the analytes. However, Method 537 requires that all the PFAAs be purchased as 

technical grade standards or neat material, if commercially available. Section 12.4 of Method 537 

describes how to sum the areas of the isomers and it only referred to four method analytes (the ones 

that then could be purchased as technical grade). The UCMR 3 Laboratory Approval Requirements 

and Information Document will note that if technical grade PFOA, PFNA, PFHpA, and PFBS are 

commercially available, the quantitation should be performed as described in Section 12.4 of the 

method. 

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31741

Comment Code: 36010

Comment: f. We are surprised at the relatively high MRLs proposed for the UCMR3 PFCs by 

method 537. Our experience in performing an in-house LCMRL determination with that method 

(and the LCMRL data shown in the method itself) was that one could reliably measure the UCMR3 

analyte list at MRLs of 0.001 to 0.010 ug/L. This makes us suspect that the labs used for 

confirmation of the LCMRL were perhaps not taking all of the necessary precautions to avoid blank 
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contamination. However we applaud the relatively high proposed MRLs for this method because we 

think it will minimize the likelihood of false positives.

Response: MRLs were determined based upon data generated by multiple laboratories. While an 

individual laboratory may be able to achieve lower LCMRLs, MRLs are based upon a statistical 

evaluation of these data from multiple laboratories and represent, within 95% confidence, the 

concentration that 75% of the laboratories can achieve. Please see response to comment code 36010 

EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31744

Comment Code: 36010

Comment: 4. For Method 537, we believe that the relatively high MRLs could justify tighter QC 

limits than the 50-150% at the MRL level, which would improve the quality of the data. However if 

the MRLs are indeed considered reflective of overall national lab capabilities this might not be the 

case.

5. Method 537 requires the use of 3 surrogates and 3 internal standards, but one of the surrogates 

and one internal standard is only applicable to compounds that are not included in UCMR3 and that 

surrogate and internal standard therefore, should be omitted. Including them unnecessarily 

complicates the method for UCMR3 purposes. 

6. PFOS may exist in both linear and branched chains. The current method uses linear PFOS for 

calibration, but in nature most PFOS is in branched chains. The response factor of the LC-MSMS to 

PFOS is dependent on the form. It is thus possible that positive results could be biased either high 

or low if the form that is present is not linear PFOS. This should be considered in interpreting data 

from UCMR3.

Response: The method was developed based on all 14 target analytes. Since the UCMR 3 

Assessment Monitoring list does not include NMeFOSAA or NEtFOSAA, EPA agrees that the 

internal standard and surrogate analyte that are used in the quantitation of these analytes is not 

necessary for UCMR 3 purposes.

EPA disagrees concerning the forms of the PFCs. The method states in Section 7.2.3. "PFHxS and 

PFOS must be purchased as technical grade (containing branched and linear isomers), as well as 

NEtFOSAA and NMeFOSAA (if commercially available)." All data in the method were obtained 

with a standard containing both linear and branch isomers and those isomers can be observed in 

Figure 1 of the method. 

Please see response to comment code 36010 EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories
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Letter ID: 0047

Comment ID: 31745

Comment Code: 36010

Other EPA Comment Codes and Descriptions: 32010 EPA Method 524.3 - VOCs

Comment: 7. The definition of Field Reagent Blank (FRB) differs between 524.3 and 537, both 

UCMR3 methods. 537 requires that the FRB be opened in the field and transferred to the container. 

However method 524.3 states "FRB - 524.3" An aliquot of reagent water that is placed in a sample 

container in the laboratory and treated as a sample in all respects, including shipment to the 

sampling site, exposure to sampling site conditions, storage, preservation, and all analytical 

procedures. The purpose of the FRB is to determine if method analytes or other interferences are 

introduced into the samples during transport and storage.... Do not open FRBs in the field; FRBs 

must remain sealed until analysis." Is it the intention to have the same "sample type" treated

differently for different UCMR3 methods?

Response: The differing procedures for handling field blanks results from the differing probable 

sources of sample contamination. In the case of Method 537 (hormones) the most likely source of 

contamination is from samplers and laboratory people that handle the samples and are taking 

hormone replacement or adjustment medications. In the case of Method 524.3 (VOCs) the 

compounds are much more volatile than the hormones and are more likely to enter the samples 

through the bottle seal during transport and storage. Opening the volatile samples would result in a 

headspace being formed, causing a loss of dissolved volatile compounds. 

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31746

Comment Code: 36010

Comment: 8. At present a field blank is required for method 537, and the guidance in that method 

(which we assume is also relevant to the UCMR) is to reject any samples with hits when there is a 

positive field blank. Given the relatively high MRLs for UCMR3 for method 537, we think it 

unlikely that there will be many cases where a field blank exceeds 1/3 of the MRL. However, 

because of the relatively short holding time for method 537 extraction it is unrealistic to expect that 

labs will only extract and analyze the field blank after finding a positive hit in the associated sample. 

At a minimum, labs will likely need to extract the field blank to ensure that holding times are met. 

This will increase the cost for utilities. While we agree that a field blank is desirable, we suggest that

EPA consider making the use of a field blank optional, or sequential, such that a utility could have 

several options: (1) collect field blanks for all samples (highest cost option); (2) analyze samples 

without a field blank and if results were positive a utility could either accept results as reported by 

the lab or invalidate the samples and do an immediate recollection within a specified period of time 

(e.g. 2 weeks) with a field blank (middle cost option); (3) require that once a site had a positive value 

all subsequent samples from that site must include a field blank (lowest cost option). Each of these 

options makes the UCMR3 database more complex, but with the large number of utilities that will 

need to perform this method, the additional cost of a field blank collected and at least partially 

analyzed with every sample is significant.
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9. On the analytical costs included in the UCMR3 supporting documents it appears that the cost of a 

field blank for a method such as 537 was not included in the estimates, which makes the cost 

estimates unduly low, as noted in our earlier comment.

Response: Please see response to comment code 36010 EPA Method 537 Rev 1.1 - PFCs.

Field blanks are required only for analytes that may easily be introduced into a field sample during 

the sampling process itself or more commonly during transport or storage. For this reason, only the 

field blank that has traveled and been stored with each field sample is valid. If a positive result is 

seen in a field sample, it is necessary to analyze the associated field blank to insure that that positive 

result did not occur during sample transport and collection. Allowing a PWS to accept positive 

results does not address the problem of field samples that were contaminated during transport and 

storage, leading to false positives. Requiring field blank analysis only in samples collected subsequent 

to the finding of a positive field sample again does not address the problem of contamination during 

transport and storage. 

Estimates of the number of expected positive results and the increased costs of having to analyze 

the accompanying field blank have been included in the overall cost estimates for the survey.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31802

Comment Code: 36010

Comment: May 2, 2011

Water Docket Attn: Docket ID No. EPA-OW-2009-0090 U. S. Environmental Protection Agency 

Mail Code 282211T 1200 Pennsylvania Ave., NW Washington DC 20460 Submitted via 

regulations.gov RE: FluoroCouncil comments on "Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR 3) for Public Water Systems," Docket EPA- OW-2009-0090

To Whom It May Concern: 

The Global Industry Council for FluoroTechnology (FluoroCouncil) respectfully submits to the U.S. 

Environmental Protection Agency (EPA) these comments concerning the Agency’s proposed 

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

Systems" (76 Fed. Reg. 11713, Mar. 3, 2011).

The FluoroCouncil is a global membership organization representing the world’s leading 

manufacturers of fluoropolymers, fluorotelomers, and other fluorinated surfactants and surface 

property modification agents. [FN1: The FluoroCouncil’s members are Asahi Glass Co., Ltd., 

Clariant Corporation, Daikin Industries, Ltd., E. I. du Pont de Nemours and Company, and Solvay 

S.A.] The FluoroCouncil has a fundamental commitment to product stewardship and, as part of its 

mission, addresses science and public policy issues related to fluoro-technology including 

perfluorinated chemicals. 
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The FluoroCouncil supports drinking water standards that protect public health and reflect the best 

available scientific evidence and the EPA’s commitment to a sound science approach to the 

development of National Primary Drinking Water Standards (NPDWS). To that end, we support 

the collection of reliable and accurate occurrence data for unregulated drinking water contaminants. 

Because perfluorinated chemical occurrence data collected through the UCMR 3 program will be 

used to inform the Agency as it evaluates and prioritizes unregulated contaminants for potential 

future regulation, such data must be gathered using sound analytical methods and laboratory 

techniques. Only through the use of sound, validated methodologies can EPA’s regulatory decisionmaking process be informed by reliable data that accurately reflect perfluorinated chemical

occurrence in drinking water. 

In response to EPA’s request for comment on changes between UCMR 2 and UCMR 3 (76 FR 

11716), the FluoroCouncil offers the following comments on the proposed UCMR 3 to help ensure 

the collection of accurate monitoring data for the six perfluorinated chemicals. 

1. To ensure UCMR 3 data are representative of actual sample concentrations, EPA should 

minimize perfluorinated chemical background contamination in UCMR 3 laboratories and 

adequately account for laboratory background contamination when establishing reporting levels for 

perfluorinated chemicals. 

In Table 1 - UCMR Contaminant List (76 FR 11735), EPA proposes a minimum reporting level 

(MRL) of 20 ng/L for perfluorooctanoic acid (PFOA) and MRLs of 10 to 90 ng/L for the 

remaining UCMR 3 perfluorinated chemicals. Section 6.12.1 of EPA’s new Method 537 (Version 

1.1) notes, "It is not possible to remove all PFAA [perfluorinated alkyl acid] background 

contamination" from the liquid chromatography with tandem mass spectrometry (LC/MS/MS) 

instrument.

The inclusion of such low MRLs in the UCMR 3 proposal, when combined with the reality of 

background levels of perfluorinated compounds in the laboratory, creates a major challenge for 

water systems trying to perform UCMR 3 monitoring for perfluorinated chemicals. 

a. UCMR 3 procedures for monitoring perfluorinated chemicals must adequately address the 

prevalence of background contamination of perfluorinated chemicals in analytical laboratories and 

minimize such background in UCMR 3 laboratories performing perfluorinated chemical analysis.

FluoroCouncil member company experience indicates that background contamination of 

perfluorinated chemicals in standards and samples at contract analytical laboratories is common. 

Members report that one laboratory took three months to reduce their background levels and had to 

use two additional laboratories (one for cleaning and a "new" lab to receive the cleaned items) 

before they were ready to resume work. Another laboratory had to do a thorough lab cleanup, 

including a solvent scrubbing of their hood to reduce background. This laboratory then instituted a 

policy to keep samples and standards in a different part of the building on a separate ventilation 

system. A third laboratory inadvertently contaminated all surfaces by drying contaminated soil 

samples on the bench top. Another laboratory usually reports 5 to 10 ppt background in most 

sample sets.

A number of authors in the scientific literature have also noted the importance of background 

contamination during the analysis of perfluorinated chemicals. Yamashita et al. (2005) state "One of 
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the major problems associated with trace- level analysis of perfluorinated acids, particularity PFOS 

[perfluorooctane sulfonate] and PFOA, is background contamination in analytical blanks." Martin et 

al. (2004) observe "Contamination sources of perfluoroalkyl substances in the laboratory are not well 

characterized but presumably are numerous given their current use in many retail products and 

common laboratory consumables." De Voogt and Saez (2006) point out the importance of proper 

sample handling to reduce contamination and analyte loss in their review of analytical techniques for

perfluoroalkylated substances. Martin et al. (2004) mention ways to minimize contamination 

including the use of solvent-only injections "after high- concentration samples or standards to 

examine for carryover." Larsen and Kaiser (2007) suggest other techniques such as flushing and 

rinsing the chromatography system in case of analyte buildup ("i.e., if the minimum background rises 

with time").

In order to minimize potential background levels at UCMR 3 laboratories, the EPA should - provide 

clear warning to potential laboratories for UCMR 3 perfluorinated chemical analysis about 

background contamination due to the unique nature of these compounds (e.g., sublimation, see 

comment 2.a), - advise such laboratories on special measures to reduce the possibility of crosscontamination, - address the need for sample storage and distribution (including the balance) to be 

distinct from the area where standards are made and stored in either Method 537 or the final UCMR 

3 regulation, - eliminate Method 537’s requirement to evaporate extracts to dryness to help prevent 

cross-contamination (see comment 2.a), - carefully evaluate the potential for and presence of 

background contamination at prospective laboratories during the laboratory approval process, and - 

monitor contamination prevention performance as part of routine laboratory auditing during the 

conduct of UCMR 3 monitoring. 

Response: Please see response to comment code 36010 EPA Method 537 Rev 1.1 - PFCs.

During methods development, the stability of the evaporation step was evaluated. Extracts were 

evaporated to dryness as the method directs, then left in the heated water bath at 62 degrees Celsius 

with nitrogen blowing for two hours after dryness was achieved. Recoveries for the UCMR 3 

analytes were as follows: PFBS 89% with 5.8% relative standard deviation (RSD), PFOA 94% with 

5.6% RSD, PFOS 100% with 6.1% RSD, PFHxS 92% with 5.1% RSD, PFHpA 85% with 4.8% 

RSD, and PFNA 89% with 5.2% RSD. Under the conditions described in Method 537, volatility 

losses due to evaporation to dryness were not observed nor were losses observed in the two 

laboratories that participated in the second laboratory demonstration. In addition, EPA found that 

going to dryness was necessary to get accurate data for all 14 analytes because the amount of water 

in the final extract significantly affected the recoveries of the longer chain PFCs, thus the only way 

to control the amount of water in the method extracts was to evaporate to dryness.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31803

Comment Code: 36010

Other EPA Comment Codes and Descriptions: 40000 Minimum Reporting Level 

Determination/LCMRLs
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Comment: b. EPA should rely on actual laboratory blank analytical results to factor laboratory 

background contamination into the determination of final UCMR MRLs for perfluorinated 

chemicals.

EPA proposes to use a statistical methodology as the basis for Lowest Concentration Minimum 

Reporting Levels (LCMRLs) and MRLs in UCMR 3 (76 FR 11720).

Trace analysis for chemicals that are common laboratory contaminants warrants a different 

approach than the proposed LCMRL/MRL methodology to minimize false positives. The Federal 

Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act 

Programs (FACDQ) expressed concern about false positives, recommending "a<=1% false positive 

rate be used for detection" (FACDQ, 2007).

Method 537 recognizes the potential for background contamination and invalidates results where 

the laboratory blank exceeds 1/3 of the MRL, effectively indicating that results within a factor of 3 

of the MRL should be considered non-detect. However, longstanding EPA data validation 

guidelines provide for qualifying sample results within 5 times the value of the highest laboratory 

blank associated with an analytical batch as non-detect (EPA, 1999; EPA Region IV, 1999). 

Consistent with this approach, the 1/3 MRL threshold would be replaced by a 1/5 MRL threshold. 

Risha et al. (2005) used 20% of the lower limit of quantitation (LLOQ) as the criterion for the 

absence/presence of significant interferences in the analysis of compounds including PFOA and 

perfluorononanoic acid (PFNA). These authors "recommended that a standard solution be run on 

the LC/MS/MS corresponding to the estimated LLOQ (25 ng/L) in matrix and a signal-to-noise 

ratio be obtained for the analyte transition of at least 5:1 compared to a reagent blank." In this way, 

Risha et al. (2005) assured a consistent way for assuring that results reported at or above the LLOQ 

(equivalent to MRL) were clearly distinguishable from background contamination present in the 

laboratory. 

The FluoroCouncil agrees with the following statement from Section 9.3.1. of Method 537 (Version 

1.1), "Because background contamination is a significant problem for several method analytes, it is 

highly recommended that the analyst maintain a historical record of LRB data." These Laboratory 

Reagent Blank data would provide the information needed to have a sufficient population of actual 

laboratory blank results (e.g., =10) to serve as the basis for calculating MRLs as 5 times the average 

blank data. A laboratory could begin assembling its historical record of LRB data during Proficiency 

Testing (as part of the Laboratory Approval Process) prior to the start of UCMR 3 monitoring. EPA 

could assess Proficiency Testing blank results against a set of target MRLs as part of its evaluation 

and approval of laboratories for UCMR 3 perfluorinated chemical monitoring. 

Setting MRLs for perfluorinated chemicals in the final UCMR 3 regulation to 5 times the average 

blank level (rather than through the approach described in the LCMRL document accompanying the 

proposed UCMR 3 regulation) would make Method 537 reporting for UCMR 3 consistent with the 

ultimate reporting approach supported by EPA data validation guidelines (EPA, 1999; EPA Region 

IV, 1999; EPA, 2008).

In addition, the FluoroCouncil recommends that EPA set MRLs for UCMR 3 laboratories 

performing perfluorinated chemical analysis at 5 times the laboratory’s average blank level to assure 

that UCMR 3 concentrations are representative of actual concentrations rather than background 
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contamination. Alternatively, EPA could prescribe national MRL values in Table 1 of the final

UCMR 3 regulation that take available data (including those generated during demonstration testing 

proposed in comment 2) on laboratory background contamination (e.g., 25 ng/L MRL for PFOA 

based on 5 ng/L background) into account and then require UCMR 3 laboratories performing 

perfluorinated chemical analysis to demonstrate background levels less than or equal to 1/5 of the 

MRL on an ongoing basis during UCMR 3 monitoring. 

c. UCMR 3 procedures should provide for routine analysis of laboratory and field blanks for 

adequate assessment and qualification of pefluorinated chemical blank contamination. 

Section 9.3.1 of Method 537 (Version 1.1) requires analysis of a Laboratory Reagent Blank with each 

analytical batch and states "Background from method analytes or other contaminants that interfere 

with the measurement of method analytes must be below 1/3 of the MRL". Section 9.3.8 of Method 

537 (Version 1.1) notes "Analysis of the FRB [Field Reagent Blank] is required only if a Field Sample 

contains a method analyte or analytes at or above the MRL".

Longstanding EPA data validation guidelines provide for qualifying sample results within 5 times the 

value of the highest laboratory blank associated with an analytical batch as non-detect (EPA, 1999; 

EPA Region IV, 1999). More recent EPA guidelines (EPA, 2008) effectively continue this practice, 

especially for laboratory blanks or field blanks containing common laboratory contaminants relevant 

to the target analytes.

Method 537 or the final UCMR 3 regulation should allow for qualifying low level apparent 

detections within a factor of 5 of the highest laboratory blank in the corresponding analytical batch 

as non-detects, in addition to those situations with greater than or equal to 1/3 the MRL where 

Method 537 specifies re-analysis or re-sampling. Additionally, in order to maximize the utility of the 

laboratory blanks for assessing background contamination, it is important for EPA to assure that 

each UCMR 3 perfluorinated chemical analytical laboratory consistently concentrates the extract to 

the same fixed final volume (see comment 2) and to always use the same volumes for lab blanks as 

are used for study samples through periodic EPA audits of the laboratories performing UCMR 3 

analysis for perfluorinated chemicals.

In order to ensure that background contamination in the laboratory is not included in the UCMR 3 

data set as actual results, analytical laboratories must be required to take special measures to reduce 

the possibility of cross- contamination, MRLs must adequately factor in laboratory blank 

contamination levels, a sufficient number of blanks must be collected, analyzed, and assessed, and 

water systems must be allowed to qualify apparent detections within 5 times the highest blank in 

corresponding analytical batch as non-detects.

Response: Regarding your comments on invalidating results due to background contamination, 

EPA has evaluated LRB data and they easily meet the "1/3 of MRL" requirement of the method. 

The "long standing EPA data validation guidelines from Region IV" were developed for Region IV's 

superfund contract work and are not directly relevant to drinking water analysis nor has this ever 

been a drinking water guideline. http://www.epa.gov/region4/sesd/oqa/rassop-organics.pdf. 

Regarding your comments on the FACDQ procedure and field blanks, please see the response to 

comment code 40000 Minimum Reporting Level Determination/LCMRLs. 
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36010 EPA Method 537 Rev 1.1 - PFCs Page 230 of 401

Please see response to comment code 36010 EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31804

Comment Code: 36010

Comment: 2. EPA's new Method 537 should be revised and demonstrated as fit for purpose across 

the expected range of drinking water samples before widespread use in UCMR 3 monitoring. 

a. EPA should modify Method 537 to exclude reduction of solid-phase extraction (SPE) cartridge 

extracts to dryness in order to prevent analyte loss and subsequent cross-contamination from that 

loss to other samples in the laboratory. 

The UCMR 3 proposed rule designates EPA’s new Method 537 for analysis of perfluorinated 

chemicals in drinking water (Table 1, 76 FR 11735). In Section 11.5 of Method 537 (Version 1.1), 

the extract from the solid-phase extraction (SPE) cartridge is concentrated to dryness under a gentle 

stream of nitrogen in a heated water bath (60-65oC) to remove all the water/methanol mix.

Data from the peer-reviewed literature show that PFOA sublimes (i.e., goes from the solid to the gas 

phase) (Barton et al. 2008 and Barton et al. 2009). Another paper provides vapor pressure data for 

PFOA and PFNA (Kaiser et al., 2005) which indicate PFNA’s vapor pressure is slightly lower than

vapor pressure of PFOA. Experimental results indicate an average rate of PFOA sublimation loss of 

0.36 mg/h at a temperature of 45oC (Kaiser et al., 2010). The vapor pressure of perfluoroheptanoic 

acid is expected to be slightly greater than that of PFOA. Because these perfluorocarboxylic acids 

are known to sublime, heating them to dryness at 60-65 oC would provide a significant opportunity 

for analyte loss. Such loss would lead to low bias in the determination and contribute to background 

contamination in the analytical laboratory, in turn potentially affecting other samples.

The FluoroCouncil recommends that EPA revise Section 11.5 of Method 537 to specify a final 

extract volume of 0.5 mL consistent with Section 8.1.4 of ISO 25101 (ISO, 2009) in accord with the 

Agency’s use of consensus organization- developed methods elsewhere in UCMR 3. (The remaining 

solvent can be mixed with a small quantity of the initial chromatographic mixture to reduce overall 

solvent strength of the injected volume.) 

b. EPA should conduct additional near-term studies to ensure acceptable performance of Method 

537 across the range of drinking water samples subject to UCMR 3 monitoring. 

Section 13.5 of Method 537 (Version 1.1) indicates that EPA and two external laboratories have 

demonstrated Method 537 performance. Method 537 is a new method with novel approaches to 

certain aspects of the analysis. For example, Section 6.9.1 of Method 537 (Version 1.1) specifies use 

of SPE cartridges containing styrenedivinylbenzene (SDVB) adsorbent.

Of over 500 peer-reviewed literature papers concerning analysis of perfluoroalkyl compounds, only 

two were found (Shoemaker et al., 2009 and Hori et al., 2004) that used SDVB cartridges for 

extraction. The Shoemaker paper was a contribution from the EPA describing the development of 
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Method 537. The Hori paper used modified SDVBs. All other relevant papers made use of C18, 

weak anion exchange (WAX), or hydrophilic lipophilic balanced (HLB) cartridges for SPE. For 

example, a method widely used in the U.S. for analysis of PFOA and PFNA in water relies on C18 

for extraction (Risha, et al., 2005). Analysis of split samples has shown that analysis based on WAX 

for SPE was able to detect perfluorohexanoic acid (PFHxA) not detected when HLB was the SPE 

cartridge (Taniyasu, et al., 2005), thereby highlighting the importance of SPE cartridge selection 

during analysis of perfluorinated chemicals. While Section 13.5 of Method 537 (Version 1.1) 

indicates that two external laboratories have demonstrated Method 537 performance, details on 

experimental design and data resulting from those demonstrations have not been provided. 

The paucity of SDVB experience in perfluorinated chemical analysis in water raises a number of 

questions about the adsorption-desorption characteristics of the cartridge in this service and the 

ability of the method to accommodate the potential effects of hardness, pH, and other differences 

among the variety of drinking water sources in the U.S. The use of a different SPE cartridge than the 

types generally used in the literature, and the relatively small sample set for results reported in 

Section 17 of the Method, indicate the possibility of untested problem areas in Method 537. As 

proposed, the first comprehensive evaluation of this method over a wide range of drinking water 

samples would come during UCMR 3 monitoring. Requiring thousands of water systems to use a 

new analytical method with a somewhat untried SPE cartridge at its core is not a wise use of 

resources.

Prior to widespread use in UCMR 3 monitoring at thousands of water utilities, Method 537 (revised 

to exclude reduction of SPE extract to dryness) should undergo further testing at two or three 

external laboratories to demonstrate performance of the SPE cartridge and the entire method with 

about 20 samples representative of the expected range of drinking water samples.

Response: Please see response to comment code 36010 EPA Method 537 Rev 1.1 - PFCs.

During methods development, the stability of the evaporation step was evaluated. Extracts were 

evaporated to dryness as the method directs, then left in the heated water bath at 62 degrees Celsius 

with nitrogen blowing for two hours after dryness was achieved. Recoveries for the UCMR 3 

analytes were as follows: PFBS 89% with 5.8% relative standard deviation (RSD), PFOA 94% with 

5.6% RSD, PFOS 100% with 6.1% RSD, PFHxS 92% with 5.1% RSD, PFHpA 85% with 4.8% 

RSD, and PFNA 89% with 5.2% RSD. Under the conditions described in Method 537, volatility 

losses due to evaporation to dryness were not observed nor were losses observed in the two 

laboratories that participated in the second laboratory demonstration. In addition, EPA found that 

going to dryness was necessary to get accurate data for all 14 analytes because the amount of water 

in the final extract significantly affected the recoveries of the longer chain PFCs, thus the only way 

to control the amount of water in the method extracts was to evaporate to dryness. 

SDVB is a very common SPE sorbent although it has not been used frequently by laboratories 

analyzing PFCs. As noted by the commenter, the HLB cartridges are commonly used for PFC 

analyses, but very limited in the number of vendors available to provide an equivalent product. Many 

of the PFCs can be adequately recovered on a variety of sorbents. EPA chose to use a very generic 

type of sorbent that is available from a number of vendors. Regarding the potential effects of 

hardness, pH, and various drinking water matrices on the ability of SDVB to adequately recover the 

PFCs, Method 537 was tested under many extreme drinking water conditions. For example, water 

high in hardness was tested as well as treated source water high in total organic carbon. The effect of 
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pH on the recovery of the PFCs on SDVB is negated as the samples are buffered with Trizma to pH 

7. Several drinking water matrices from other parts of the country were also evaluated during the 

multi-laboratory verification studies with no adverse effects.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31807

Comment Code: 36010

Other EPA Comment Codes and Descriptions: 40000 Minimum Reporting Level 

Determination/LCMRLs

Comment: 5. Conclusion 

Overall, the FluoroCouncil is concerned that, as proposed, Method 537 and other requirements for 

UCMR 3 monitoring of perfluorinated chemical occurrence in drinking water will lead to the 

generation of inaccurate data, inappropriate as the basis for future regulation. Additionally, the 

proposed new LCMRL approach should not be implemented in support of UCMR 3 or any other 

rulemaking without appropriate peer review and additional public comment. 

We appreciate the opportunity to provide information and comment on the proposed UCMR 3. In 

addition, we would welcome the opportunity for our technical experts to meet with EPA to discuss 

our suggestions to minimize laboratory background contamination and to improve Method 537 

prior to its use in UCMR 3. If you have any questions or would like to arrange a meeting, please 

contact Jessica Steinhilber at 202-249-6737 or jessica_steinhilber@americanchemistry.com.

Sincerely,

Jessica S. Steinhilber FluoroCouncil 

Appendix: References

APPENDI

XReferences

Barton, C.A, Botelho, M.A., and Kaiser, M.A., 2008. "Solid Vapor Pressure and Heat of Sublimation 

for Perfluorooctanoic Acid, J. Chem. Eng. Data, C., 53, 939-941.

Barton, C.A., Botelho, M. A., and Kaiser, M.A., 2009. "Solid Vapor Pressure and Heat of 

Sublimation for Ammonium Perfluorooctanoate, J. Chem. Eng. Data, 54(3), 752-755.

de Voogt, P. and Saez, M., 2006. "Analytical chemistry of perfluoroalkylated substances", Trends in 

Analytical Chemistry, 25, 326-342.

EPA, 1999. "USEPA Contract Laboratory Program National Functional Guidelines for Organic 

Data Review", OSWER 9240.1-05A-P, PB99-963506, EPA540/R-99/008.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

36010 EPA Method 537 Rev 1.1 - PFCs Page 233 of 401

EPA Region IV, 1999. "Data Validation Standard Operating Procedures for Contract Laboratory 

Program Routine Analytical Services", revision 2.1, Science and Ecosystem Support Division, Office 

of Quality Assurance.

EPA, 2004. "Statistical Protocol for the Determination of the Single-Laboratory Lowest 

Concentration Minimum Reporting Level (LCMRL) and Validation of Laboratory Performance at 

or Below the Minimum Reporting Level (MRL)", EPA Document # 815-R-05-006.

EPA,2008. "USEPA Contract Laboratory Program National Functional Guidelines for Superfund 

Organic Methods Data Review", OSWER 9240.1-48, USEPA-540-R-09-01.

FACDQ (Federal Advisory Committee on Detection and Quantitation Approaches and Uses in 

Clean Water Act Programs), 2007. Report of the Federal Advisory Committee on Detection and 

Quantitation Approaches and Uses in Clean Water Act Programs.

Gu, J., Ghosal, S., and Roy, A., 2008. "Bayesian Bootstrap Estimation of ROC Curve", Stat Med, 

27(26), 5407-20.

Helsel, D.R., 2005. Nondetects and Data Analysis. Wiley, Hoboken, New Jersey.

Hori, H., Hayakawa, E., Yamashita, N., Taniyasu, S., Nakata, F., and Kobayashi, Y., 2004. "Highperformance liquid chromatography with conductimetric detection of perfluorocarboxylic acids and 

perfluorosulfonates", Chemosphere, 57, 273-282.

ISO, 2009. ISO 25101 - Water Quality - Determination of perfluorooctanesulfonate (PFOS) and 

perfluorooctanoate (PFOA) - Method for unfiltered samples using solid phase extraction and liquid 

chromatography/mass spectrometry.

Kaiser, M.A., Larsen,B.S., Kao, C.P.C. and Buck, R.C., 2005. "Vapor pressures of perfluorooctanoic, nonanoic, -decanoic, -undecanoic, and -dodecanoic acids", J. Chem. Eng. Data, 50, 1841-

1843.

Kaiser, M.A., Barton, C.A., Botelho, M.A., and Dawson, B.J., 2010."Understanding potential 

exposure sources of perfluorinated carboxylic acids in the workplace", M. A. Kaiser, C. A. Barton, 

M. A., The Annals of Occupational Hygiene, 54, 915-922.

Larsen, B.S. and Kaiser, M.A., 2007. "Challenges in perfluorooctanoic acid measurements", Anal. 

Chem., 79, 3966-3973.

Martin, J.,Kannan, K., Berger, U., de Voogt, P., Field, J., Franklin, J., Giesy, J. P., Harner, T., Muir, 

D.G.C., Scott, B., Kaiser, M., Jaernberg, U., Jones, K.C., Mabury, S.A., Schroeder, H., Simcik, M., 

Sottani, C., Van Bavel, B., Kaerrman, A., Lindströem, G., and van Leeuwen, S., 2004. "Analytical 

challenges hamper perfluoroalkyl research", Environ. Sci. & Tech., 38(13), 248A-255A.

Parzen, M.,Lipsitz, S.R., and Fitzmaurice, G.M., 2005. A note on reducing the bias of the 

approximate Bayesian bootstrap imputation variance estimator, Biometrika 92 (4), 971-974.
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36010 EPA Method 537 Rev 1.1 - PFCs Page 234 of 401

Risha, K., Flaherty, J., Wille, R., Buck, W., Morandi, F. and Isemura,T., 2005. "Method for Trace 

Level Analysis of C8, C9, C10, C11, and C13 Perfluorocarbon Carboxylic Acids in Water", Anal. 

Chem., 77, 1503-1508.

Rocke,D.M. and Lorenzato, S., 1995. "A two-component model for measurement error in analytical 

chemistry", Technometrics 27, 176-184.

Shoemaker, J.A., Boutin, B.,and Grimmett, P., 2009. "Development of a U.S. EPA drinking water 

method for the analysis of selected perfluoroalkyl acids by solid-phase extraction and LC-MS- MS", 

J. Chromatogr. Sci., 47, 3-11.

Taniyasu, S., Kannan, K., So M.K.,Gulkowska, A., Sinclair, E., Okazawa, T., and Yamashita, N., 

2005. "Analysis of fluorotelomer alcohols, fluorotelomer acids, and short- and long-chain 

perfluorinated acids in water and biota", J. Chrom. A., 1093, 89-97.

Yamashita,N., Kannan, K., Taniyasu, S., Hori, Y., Petrick, G., and Gamo, T., 2005. "A global survey 

of perfluorinated acids in oceans", Marine Pollution Bulletin, 51,658-668.

Response: Please see the response to comment codes 40000 Minimum Reporting Level 

Determination/LCMRLs and 36010 EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32077

Comment Code: 36010

Comment: 3. EPA Method 537 is certified in New Jersey, but is only in use by a handful of labs. 

The guidance for treatment of field blanks is clear in the method, but not in the UCMR3 Rule itself.

Response: The treatment of field blanks has been addressed in the UCMR 3 Laboratory Approval 

Requirements and Information Document. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32079

Comment Code: 36010

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: Based on past experience, we expect EPA methods 539 and 537 to be rugged, but we 

question whether their performance has been demonstrated rigorously at the proposed LCMRL 

level. Laboratories would benefit from some time to bring the method on line and use them prior to 

UCMR3 (e.g. a shake-down period to work out the idiosyncrasies of these methods) and to gather 

additional information to inform MRL determination. EPA should work with the broader drinking 

water community data to collect additional data that would inform understanding of method 
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36010 EPA Method 537 Rev 1.1 - PFCs Page 235 of 401

performance and provide an opportunity to standardize improvements to these methods - this could 

take the form of a multi-laboratory method trial prior to finalizing UCMR3 or be an element of 

laboratory approval during UCMR3 preparatory phase.

Response: Please see response to comment codes 31010 EPA Method 539 - Hormones and 36010 

EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32083

Comment Code: 36010

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: AWWA also recommends that EPA provide specific UCMR3 guidance for handling 

data when there is a positive field blank. Currently, EPA Method 537 requires a field blank, and a 

field blank is also appropriate for EPA Method 539 samples. The guidance in EPA Method 537 

requires invalidating results and recollecting samples if positive results are found in the field blank 

above 1/3 of the MRL and positive results are also found in samples, regardless of level. While we

think it unlikely that there will be many cases where field blanks exceed 1/3 of the MRLs proposed 

in UCMR3 for EPA Method 537 analytes, we believe this still has the potential to require 

unnecessary recollection and recommend that EPA modify the guidance to only require recollection 

if sample results are <10X the level found in the field blank. We believe this type of guidance is even 

more critical for EPA Method 539, in light of the very low MRLs proposed for some of the 

hormones. EPA also needs to be sure that the database will capture the necessary information on 

either sample rejection or relative field blank measurements.

Response: Please see response to comment codes 31010 EPA Method 539 - Hormones and 36010 

EPA Method 537 Rev 1.1 - PFCs.

While EPA will evaluate all field blank and other quality control data for the laboratories under 

contract to EPA to provide the small system monitoring, it is beyond the capabilities of the 

SDWARS to collect and evaluate this large quantity of data for the large system component. It is the 

responsibility of the PWS to assure that their laboratory only report data to SDWARS that meets all 

of the quality control requirements. EPA will conduct periodic audits of laboratories to assure that 

these requirements are understood and are being met. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32086

Comment Code: 36010

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: Appropriate MRLs? Sound technical reasons point to revisiting the MRLs included in 

the proposed UCMR3 notice. 
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36010 EPA Method 537 Rev 1.1 - PFCs Page 236 of 401

Excessively Low Reporting Levels Endanger the Credibility of the Data All but two of the proposed 

reporting levels are at sub-part per billion concentrations and many much lower. For example, all 

but two of the listed hormones are at sub- part per trillion levels (e.g., 17-ß-estradiol, 0.0004 ug/L 

and testosterone 0.0001 ug/L). There are recognized instances of laboratory sample contamination

of low-level hormone samples by laboratory technicians with good experimental technique but who 

were taking birth control at the time they processed samples. At these very low concentrations, the 

observations are very sensitive to the:

1. Competency of the laboratory with the analytical method,

2. Field and in-laboratory sample handling conditions and practices, and 

3. Contamination by experimental equipment and supplies. In California, an expert blue ribbon 

panel of toxicologists and chemists prepared a document for the State Water Resources Control 

Board (CEC Blue Ribbon Panel) where much of a chapter was devoted to the need for proper 

control and treatment of field and lab blanks for pharmaceuticals and hormones.[FN14:2010. 

California, State Water Resources Control Board. Monitoring Strategies for Chemicals of Emerging 

Concern (CECs) in Recycled Water, Recommendations of a Science Advisory Panel. June 25, 2010. 

(ftp://ftp.sccwrp.org/pub/download/DOCUMENTS/CECpanel/CECMonitoringInCA 

RecycledWater_FinalReport.pdf) This report would be a useful resource for EPA as it develops 

UCMR3 guidance for laboratory and field practices when handling samples for quantitation at these 

very low concentrations. 

Specifically, for any MRL for the perfluorinated compounds and hormones that is < 5 ng/L, it is 

desirable to develop a mechanism for interpreting (or rejecting) data based on occurrence in field 

blanks compared to occurrence in the samples. UCMR3 guidance (and not just the method itself) 

should specify that water systems also collect a field blanks to ensure that any positive observations 

for these compounds are not the result of random laboratory or field contamination. These two 

methods have extensive discussion of laboratory blanks and protocols for ensuring that actual 

analysis of field samples is not conducted unless a lab blank is <1/3 the MRL. A similar mechanism 

is warranted to address contamination during sample collection for not only EPA Method 537, but 

also EPA Method 539, and that guidance should be expanded to minimize the need for 

recollections.

Response: Please see response to comment codes 31010 EPA Method 539 - Hormones and 36010 

EPA Method 537 Rev 1.1 - PFCs.
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36020 Other Methods - PFCs Page 237 of 401

Comment Code: 36020 Other Methods - PFCs

Individual Comments

Commenter Name: Larry Zobel

Commenter Organization: 3M Company 

Letter ID: 0063

Comment ID: 31665

Comment Code: 36020

Comment: As EPA addresses the analytical issues, we also want to alert you to the forthcoming 

publication of two analytical methods that will significantly reduce the time and effort required for 

the analysis of PFCs. First, 3M will soon publish in the journal Analytical Methods a Solid Phase 

Extraction method that is far less labor intensive than Method 537. This method eliminates timeconsuming steps of bottle-rinsing and blowdown of extracts. 3M's paper has been accepted for 

publication, and we will supply EPA with the galleys when available. In addition, we are also 

preparing a manuscript describing an even more advanced method for analyzing PFCs, using largevolume injection, without solid phase extraction. This method generates equivalent data quality with 

far less work. Both methods also enhance sample holding time from 14 to 28 days. Both of these 

methods have been validated in 3M's ISO-accredited Environmental Laboratory and meet the 

Minimum Reporting Limits set out in Method 537. 

These new methods could spare municipalities and EPA significant expense. We encourage the 

Office of Water to discuss the analytical methods with EPA's analytical experts at RTP, who are 

knowledgeable about these issues, in part through technology transfers where 3M has been a 

contributor. Consistent with this track record of sharing scientific knowledge, 3M would be pleased 

to provide additional information if that would be helpful. 

Response: EPA cannot comment on a method that is not available for public use. Also, methods 

must be published and finalized in time for EPA to provide the public with the opportunity to 

comment on them before they can be used. 

EPA agrees that the blowdown and to a much lesser extent the bottle rinsing steps add time to the 

method, but these steps were necessary to achieve accurate and sensitive data. During method 

development (as shown in the supporting research summary), mean recoveries dropped as low as 

75% for the longer chain compounds. In fact, even PFOS dropped from 101% (bottle rinsed) to 

83% (no bottle rinse), indicating some adsorption of PFOS on the sample bottles. In addition, 

precision was worse for those same analytes when the bottles were not rinsed. In light of these data, 

EPA feels that it is necessary to maintain the bottle rinsing step. 

It is not clear why the commenter believes the evaporation step can be removed and still allow 

laboratories to get low MRLs unless the commenter is referring to large volume direct aqueous 

injection (DAI) methods. EPA researched DAI for the PFCs and concluded that the higher the 

chain, the more they adsorbed to the autosampler vial (and thus, delivered less sensitivity). To 

overcome this issue the aqueous sample would have to be diluted with solvent greatly reducing the 

sensitivity.
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Regarding the comment about increasing holding time from 14 to 28 days, EPA did not find an 

antimicrobial that did not affect recoveries; therefore, the holding time was set to not exceed 14 days 

without an antimicrobial present in the sample. 
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36050 Health Effects - PFCs Page 239 of 401

Comment Code: 36050 Health Effects - PFCs

Individual Comments

Commenter Name: Olga Naidenko

Commenter Organization: Environmental Working Group 

Letter ID: 0073

Comment ID: 31689

Comment Code: 36050

Comment: These substances have been detected as contaminants in people and the environment 

(Kato 2011) and pose a risk to human health. The U.S. Centers for Disease Control and Prevention 

has found PFCs in the bodies of virtually all Americans over the age of 12. EWG’s biomonitoring 

tests of cord blood sample from 20 infants born in the U.S. in the past decade found that all 

newborns had been exposed to PFCs in the womb (EWG 2009b). 

Response: EPA appreciates the toxicological information on PFCs. 
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36100 Perfluorooctane sulfonic acid (PFOS) Page 240 of 401

Comment Code: 36100 Perfluorooctane sulfonic acid (PFOS)

Individual Comments

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31903

Comment Code: 36100

Comment: Data on the occurrence of PFCs in New Jersey drinking water includes a study of

PFOA and PFOS in a 2006 NJDEP study of 23 public water supplies (NJDEP, 2007; Post et al., 

2009), additional data submitted by water purveyors, some of which is reported in Post et al. (2009), 

and a more recent 2009 NJDEP study of PFOA, PFOS, and eight other PFCs in 33 additional 

public water supplies. In the two (2006 and 2009) NJDEP studies, PFOA and PFOS were quantified 

in 59% and 29%, respectively, of the 56 public water systems tested, indicating that these two PFCs 

occur commonly in NJ public water supplies. In the 2009 study of 33 public water supplies, seven of 

the eight other PFCs that were included were detected at quantifiable levels (> 0.005 μg/L) in some 

percentage of systems tested, as follows: PFPeA-27%, PFNA-27%, PFHxA-21%, PFHxS-15%, 

PFHpA-12%, PFBS-9%, PFBA-3%, and PFDA-not detected.

Response: EPA appreciates the new PFCs occurrence data.
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Comment Code: 36200 Perfluorooctanoic acid (PFOA)

Individual Comments

Commenter Name: Wenonah Hauter 

Commenter Organization: Food and Water Watch

Letter ID: 0061

Comment ID: 31651

Comment Code: 36200

Comment: Office of Water U.S. Environmental Protection agency Mail Code 4101T 1200 

Pennsylvania Ave., NW Washington, DC 20460 May 1, 2011

Docket ID No. EPA-HQ-OW-2009-0090

Re: Food and Water Watch comments on proposed UCMR 3 for Public Water Systems 

Food & Water Watch (FWW) is a national non-profit organization that advocates for common 

sense policies that will result in healthy, safe food and access to safe and affordable drinking water. 

We work to ensure that the food, water and fish we consume is safe, accessible and sustainably 

produced. 

Through our water work, we advocate for public control of water resources and services, strong 

conservation measures and tough regulation of toxic emissions. The policies we promote will result 

in safe and affordable drinking water for everyone, rather than reliance on bottled water.

As such, FWW has reviewed the EPA’s Proposed Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR3) for Public Water Systems published in the Federal Register on 

March 3, 2011. We appreciate the opportunity to review the proposed UCMR3 document and 

provide the following comments for your consideration in finalizing the regulation. 

Perfluorooctanoic Acid 

We applaud the EPA for finally issuing monitoring guidance for perfluorooctanoic acid (PFOA), a 

processing agent used to make Teflon and other nonstick products, oil-resistant paper packaging 

and stain-resistant textiles. Though DuPont and other manufacturers have reduced their emissions 

and agreed to voluntarily phase-out the chemical, concerns remain about the possible health effects 

of PFOA. Additional concerns stem from the chemical's continued presence in consumer products, 

as well as pollution from waste-disposal practices.

Research has shown that PFOA is detectable, at low-levels, in the blood of human across the globe. 

Furthermore, recent studies have linked perfluorooctanoic acid exposure to high cholesterol, which 

is linked to hypertension, and heart disease.

Response: EPA appreciates your support and has included PFOA on the UCMR 3 Assessment 

Monitoring list. 
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36200 Perfluorooctanoic acid (PFOA) Page 242 of 401

Commenter Name: Olga Naidenko

Commenter Organization: Environmental Working Group 

Letter ID: 0073

Comment ID: 31690

Comment Code: 36200

Comment: Environmental Working Group has campaigned for eight years to restrict 

perfluorooctanoic acid (PFOA), a likely human carcinogen, endocrine-disrupting chemical and 

reproductive toxicant that for 50 years was widely used to make common non-stick and greaseproof coatings on cookware, food packaging, clothing, furniture and other popular products. As a 

result of pressure from EWG and other health advocates, in 2006, EPA and eight major makers of 

PFOA agreed on a voluntary phase-out to eliminate virtually all U.S. sources of the chemical by 

2015. But PFOA and many other potentially hazardouos perfluorinated chemicals are still used in 

factories in China and other countries and may be trace contaminants in imported cookware and 

other consumer products available on the U.S. market (Mak 2009; Zhang 2010a; Zhang 2010b)

EWG applauds the EPA decision to start nationwide monitoring for these contaminants. Efforts to 

learn the full scope of PFC pollution in the nation's drinking water are long overdue. As new science 

becomes available, researchers are finding PFCs, and particularly PFOA, to be toxic at much lower 

doses than previously understood (White 2011a; White 2011b). Studies in exposed human 

populations point to the particular danger of PFOA to hormonal function, reproduction and 

development (Apelberg 2007; Fei 2009; Joensen 2009; Knox 2011; Lopez-Espinosa 2011). The EPA 

plan represents a key step that would help define the full scope of contamination and would help 

regulators protect water sources and human health from these pollutants. 

Response: EPA appreciates your support and has included PFOA on the UCMR 3 Assessment 

Monitoring list. 
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36600 Perfluorobutanesulfonic acid (PFBS) Page 243 of 401

Comment Code: 36600 Perfluorobutanesulfonic acid (PFBS)

Individual Comments

Commenter Name: Larry Zobel

Commenter Organization: 3M Company 

Letter ID: 0063

Comment ID: 31663

Comment Code: 36600

Comment: In our comments on PFBS, we explain why PFBS does not belong on the UCMR 3 list.

PFBS shows low toxicity based on a substantial toxicological database. It has limited occurrence in 

humans based on Centers for Disease Control ("CDC") biomonitoring data, which suggests there is 

not widespread human exposure via drinking water. CDC researchers recently noted that they 

detected PFBS in blood "infrequently and at concentrations close to the LOD [Limit of Detection] 

of 0.1 ng/mL. This detection frequency is very similar to that of previous reports." (Kato el al. 2011, 

Supplemental information at page 5.) The biomonitoring data and the toxicological evidence are 

summarized below. 

Based on all of the evidence, PFBS is not an appropriate candidate for regulation given the criteria 

set forth in the Safe Drinking Water, and is distinguishable from the other PFC compounds on the 

proposed monitoring list. Accordingly, PFBS should be deleted from the proposed monitoring, 

which will provide EPA with an opportunity to choose a different substance of higher priority to 

take its place in the UCMR 3 program.

Response: Please see response to comment code 36000 Perfluorinated Compounds (PFCs). 

Commenter Name: Larry Zobel

Commenter Organization: 3M Company 

Letter ID: 0063

Comment ID: 31666

Comment Code: 36600

Comment: PFBS Comments

Without endorsing either the prioritization of the other PFCs or the characterizations found in 

EPA's supporting documentation (Possible Contaminants/or Inclusion on UCMR 3-Information 

Compendium, USEPA 2010d, hereafter "Information Compendium"), we focus our next comments 

on PFBS.

We recommend that PFBS be removed from the UCMR 3 list, in light of strong evidence of its low 

toxicity, and its sparse occurrence and markedly lower persistence in human blood compared to the 

other PFCs on the list. Removing PFBS will enable EPA to deal with another higher priority 

substance in the UCMR. 
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EPA notes that the Contaminant Candidate List 3 (CCL 3) was the starting point for substances 

considered for listing in the UCMR 3, and that the CCL 3 process considered data on potential 

adverse health effects and occurrence. (76 Fed. Reg. at 11717.) PFBS, however, is not on the CCL 3 

list. Rather, it is an addition to the UCMR 3 list proposed by a working group, based on what 

appears to be limited information on and understanding of PFBS. This submittal highlights 

important information on PFBS, much of which is already known to other offices at EPA. 

PFBS-Related Materials

Following 3M's phaseout of products based on eight-carbon PFC materials, 3M developed a more 

sustainable technology for many of these products based on four-carbon chains, using 

perfluorobutane sulfonyl fluoride (PBSF) as a starting material. PBSF, and substances derived from 

it, can break down to perfluorobutane sulfonate (PFBS).

EPA has recognized that PFBS and its precursors are distinct from the longer- chain PFCs and has 

excluded these compounds from the prohibitions on manufacturing, import and use that apply to 

longer-chain compounds. EPA's Significant New Use Rule under the Toxic Substances Control Act 

("TSCA") restricts the manufacture, import and use of longer-chain sulfonate compounds that could 

result in PFCs. Four-carbon compounds, including PFBS and its precursors, are not subject to the 

restrictions of the Significant New Use Rule. (72 Fed. Reg. 57223). Rather, the four-carbon materials 

serve as substitutes for the longer-chain materials that have been phased out of production. 

As these new products have been introduced since 2001, they have been subject to 

premanufacturing review under TSCA 3M's products that are PFBS precursors have been through 

EPA Pre-Manufacturing Notice review and are marketed with EPA's express consent. Although a 

small amount ofPFBS itself is sold by 3M and others (generally for use as a preferable substitute for 

brominated flame retardants), the vast majority of the materials that can degrade to PFBS are 

incorporated into stable polymers. While 3M is not the only manufacturer or importer of PFBSrelated materials, presumably any other precursor products have received or will also receive EPA 

scrutiny before manufacturing commences, thus limiting the potential for future groundwater 

contamination. 

Persistence and Lack of Accumulation

While PFBS is persistent in the environment, it has a relatively short half life in humans. Based on a 

study of production workers (Olsen, et al. 2007), the half-life in human blood averaged 28 days --

substantially shorter than the half-life in hwnans for any of the other longerchain PFCs on the 

proposed list UCMR 3. There is no evidence of accumulation in humans, based on biomonitoring 

data discussed below. 

In rats, PFBS has been shown to have a tenninal serum half-life of approximately 2-8 hours after a 

single dose. (Chengelis el al. 2009; Olsen et al. 2009.) In monkeys, terminal serum half-life of PFBS 

is approximately 4-5 days when serum PFBS concentrations were followed for 31 days after a single 

dose (Olsen et al. 2009). When researchers exposed rainbow trout to PFCs, "carboxylates and

sulfonates with perfluoroalkyl chain lengths shorter than seven and six carbons, respectively, could 

not be detected in most tissues and were considered to have insignificant bioconcentration factors 

(BCFs)." (Martin, et al. 2003.) Leading researchers at the University of Toronto who studied the 

atmospheric fate of NMeFBSE, a PFBS precursor, concluded, "Atmospheric oxidation 
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ofNMeFBSE leads to the fonnation of PFBS and short chain PFCAs which are not bioaccumulative 

and are not expected to pose any significant environmental threat." (D'Eon, el al., 2006.)

Occurrence Data: Water

As the Australian government observed in its assessment of PFBS, although PFBS is water soluble, 

"[c}ompared to the higher homologues (C6 and greater), there has been very limited detection of 

PFBS in the environment.... " NICNAS, Existing Chemical Hazard Assessment Report, Potassium 

Perfluorobutane Sulfonate, Nov. 2005, at p. 75, available at

http://www.nicnas.gov.au/Publications/CARJOther/Potassium_Perfluorobutane_Sulfon 

ate_PDF.pdf_ 

The Minnesota Department of Health ("MDH") has conducted extensive drinking water testing for 

PFCs in areas outside St. Paul, Minnesota, that were believed to be impacted by 3M's Cottage 

Grove, Minnesota, plant. MDH summarized the data in a report issued in conjunction with the 

federal Agency for Toxic Substances and Disease Registry. (See MDJ-I, Public Health Assessment: 

Perjluorochemical Contamination in Soulhern Washington County, Northern Dakota County, and 

Southeast Ramsey County, Minnesota, available at

http://www.health.state.mn.us!divs/eh/hazardous/topics/pfcs/phalwoodbury/index.h tml.)

* In Table 2 of the report, MDH summarizes results for 960 private and business drinking water 

wells. PFBS was only detected in 11 of the 960 wells (1%). Maximum results in ppb are tabulated 

with an overall maximum for PFBS of only 0.118 ppb.

* In Table 4, MDH presents results for PFCs in Cottage Grove City Wells. Six of the eleven wells 

are listed as "ND" for PFBS. The others have very low ranges reported, in some cases with only one 

or two "detects." The highest value listed is 0.32 ppb. Occurrence Data: Human Exposure Similarly, 

human biomonitoring data demonstrate a lack of widespread exposure in people, thus indicating a 

lack of widespread occurrence in drinking water. Two major human biomonitoring studies have 

evaluated serum PFBS concentrations in the United States general population (Calafat et af. 2007; 

Olsen et al. 2008). These studies demonstrate exceptionally low or no measurable exposure to the 

general population of the United States to PFBS:

* Calafat el al. (2007) analyzed for PFBS in 2,094 representative samples of serum from the United 

States general population, aged 12 and greater, collected in the years 2003-2004. These samples were 

collected by CDC as part of the United States National Health and Nutrition Examination Survey 

(NHANES). Less than 0.5% of the serum samples had quantifiable concentrations of PFBS above 

the lower limit of quantification of 0.4 ng/mL (Ppb). 

* CDC monitored again in 2005-2006 and in 2007-2008. The latest CDC NHANES data for PFBS 

are provided in the Supplemental Information accompanying Kato et al. (2011). The monitoring 

results for 2007-2008 are displayed in Table S5 by age, gender and race/ethnicity. The 50th, 75th, 

90th and 95th percentile values for all of these categories are all listed as less than the limit of 

detection. * Olsen el al. (2008) obtained 100 individual serum samples for persons aged 20 - 69 (l0 

samples per sex per 1O-year age group per center) from each of six regional American Red Cross 

donor centers in the United States between April and July of2006. Of these samples, less than 1% 

had quantifiable concentrations of PFBS above the lower limit of quantitation which ranged from 

0.3 to 0.5 ng/mL (ppb). The highest concentration measured was 2.9 ng/mL (Ppb). 
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3M has also analyzed blood samples for PFBS from six fluorochemicals production workers, six 

tluorochemicallaboratory workers, and six administrative workers. (Ehresman et al. 2007.) PFBS was 

found above the method lower limit of quantification of 5 nglmL (5 ppb) in only four of the six 

production workers, all of whom had a history of potential manufacturing exposure to PFBS. PFBS 

concentrations were below the lower limit of quantification in the remaining two production 

workers and all of the fluorochemicals laboratory and administration workers. For the four workers 

with measureable PFBS, serum PFBS concentrations ranged from 7 to 25 ng/mL (ppb) and 

averaged 17 ng/mL (ppb). Thus, even with occupational exposure, there is no significant 

accumulation in humans. 

The purpose of EPA's Safe Drinking Water Act regulations is to limit human exposure to regulated 

contaminants that pose a health risk. EPA can only establish Maximum Contaminant Limits under 

the Act where (i) there may be an adverse effect on health, (ii) the contaminant is known or 

substantially likely to occur in public water systems with a frequency and at levels of public health

concern, and (iii) regulation would present a meaningful opportunity for health risk reduction. 42 

U.S.C. [sec] 300g-1 (b)(l)(A). With PFBS, human exposure has already been measured, and the lack 

of widespread occurrence in blood suggests that occurrence in public drinking water supplies is 

limited.

Health Effects Evaluation: Toxicology 

The evidence on PFBS also indicates that the health risk from any exposure is low. There is a 

substantial body of toxicological testing on PFBS, which has been provided in connection with 

EPA's review of Pre-Manufacturing Notices, and which we incorporate here by reference.

3M has published several papers on PFBS in the scientific literature, none of which is cited in the 

Information Compendium for UCMR 3. Publications include Lieder et al. (2009a) on the twogeneration rat reproduction study with PFBS, Lieder et al. (2009b) on a 90-day toxicological 

evaluation ofPFBS in rats, and a comparative phannacokinetic paper in rats, monkeys and humans, 

Olsen et al. (2009).

Additional unpublished data are summarized in a 3M document describing PFBS chemistry, 

toxicokinetics, hazard assessment, mode of action, dose-response assessment, exposure evaluation, 

and risk characterization. (3M, Human Health Risk Assessment of Perfluorobutane Sulfonate 

(PFBS), October 2008.) 3M has submitted this document to EPA in connection with EPA's review 

of new chemicals, but we attach a copy here for the Water Office Docket.

To summarize the toxicology data; 

* PFBS is not metabolized and cannot covalently bond to modify biological compounds. 

* PFBS is excreted efficiently from urine and it does not bioaccumulate in rats (Chengelis et al., 

2009; Olsen et al., 2009). Estimated terminal serum elimination half-lives are 2-8 hours in rats 

(Chengelis et al., 2009; Olsen et al., 2009) and 4·5 days in monkeys (Olsen, et al. 2009.)

* In a 90-day repeated oral dose study with rats at up to 600 mglkg/day of PFBS, there were no 

significant changes in serum clinical chemistry values that would indicate systemic effects in either 
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male or female rats. There were mild histopathological changes in kidney, stomach, and nasal 

mucosa, but no changes in liver or kidney weights. These observations likely represent responses to 

mild irritation from the surfactant activity of PFBS rather than biologically significant adverse toxic 

effects. (Lieder et al 2009b.)

* In a two-generation reproductive study in rats with PFBS at up to 1000 mg/kg/day, PFBS did not 

affect postnatal survival, and there was no adverse effects on any fertility or reproduction parameters 

evaluated (Lieder et af. 2009a). * PFBS is non-genotoxic in a wide variety of test systems using 

bacteria or mammalian cells in vitro. PFBS does not pose any allergic sensitization potential in 

Guinea pigs. 

* Although PFBS has been shown to activate both rodent and human forms of xenosensor nuclear 

receptor PPARa human form of PPARa receptor were far less sensitive to activation by PFBS (Wolf 

ef al. 2008; Bjork and Wallace, 2009). In addition, hepatomegaly, one of the typical endpoints 

associated with PPARa activation in rats, was not observed in the 90-day repeated dose study 

mentioned above at doses up to 600 mglkg/day. Therefore, the arguments supporting greatly 

lessened sensitivity of human liver to PPARa would apply in the case of PFBS. 

In short, only mild effects are observed at very high doses of PFBS in rats. All of the available 

toxicity data indicate that PFBS displays a low potential for toxicity and does not show a propensity 

to build up in the body upon repeated exposure. 

Health Effects Evaluation: Deriving a Reference Dose and HRL 

As part of its Information Compendium supporting the proposed rule, EPA presents information 

on Reference Doses for the substances proposed for monitoring. The Reference Dose listed for 

PFBS is inappropriate. 

It is difficult even to derive a reference dose given thc mild effccts seen in the toxicological studies. 

Because the effects seen in rat liver appear to represent an adaptive response, rather than a toxic 

response, those effects do not provide an appropriate basis for deriving an oral reference dose 

("RfD"). The stomach effects reportcd in the 90-day study are likely due to a cumulative direct 

irritation effect of PFBS gavage dosing, and likewise do not represent an appropriate basis for 

derivation of an RfD. There is also some question whether the kidney tubule epithelial hyperplasia is 

a justified basis for the RfD in light of the likely role of PFBS' strong surfactant properties, 

combined with its rapid elimination unchanged in the urine; there were no clear changes in kidney 

function even at the highest dose in the laboratory rats. This endpoint is a very conservative basis 

for risk assessment, but of the options, appears to be the most reasonable endpoint for deriving an 

RfD in light of dose-related findings in both the 90 day study and the 2-generation study (both 

sexes, both generations). 

Based on the renal tubular epithelial hyperplasia reported in both the 90-day study and the 2-

generation reproductive toxicity study, application of EPA's benchmark dose modeling software 

(BMDS 1.4.1) yields a lower limit on benchmark dose (BMDL) for a 10% increase in the incidence 

orrenal tubule epithelial hyperplasia of37 mg/kg/day for PFBS. (3M 2008.) Using a highly 

conservative 300- fold uncertainty factor (standard factors of 10 for interspecies extrapolation, 10 

for intra-species extrapolation, and 3 for subchronic to chronic) leads to a Reference Dose of 0.12 

mg/kg/day. 
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As described in 3M (2008), using the standard procedures for deriving a drinking water criterion, 

including intake rate and a 20% relative source contribution adjustment, a healthprotective drinking 

water criterion of 840 IJ.g/L (ppb) can be derived using this RID. This contrasts starkly with the 

calculated Health Reference Level provided in the Information Compendium for PFBS of 9.8 ugIL.

EPA's Information Compendium relies on an RfD calculated by the Minnesota Department of 

Health ("MDH") to arrive at the Health Reference Level for PFBS. MDH derived a chronic value 

using the NOAEL of 60 mg/kg/day from the 90-day epeat-dose study with PFBS. That level is 

based on the occurrence of hematological changes in male rats at the next higher dose. While 

reduced red blood cell, hemoglobin and hematocrit values were seen in the PFBS-treated rats, these 

changes were mild and not clinically significant. There were no histopathological findings in bone 

marrow. As noted by the study authors: "Taking the hematology data from the study as a whole, this 

pattern would suggest slight to mild plasma volume expansion; although other potential etiologies 

cannot be ruled out with the available data." (Lieder et of. 2009b, at 50, 51.) Interestingly, Australia's 

Department of Health, National Industrial Chemicals Notification and Assessment Scheme 

assessment of the 90-day PFBS study determined the NOAEL to be 200 mg/kg/day. (Australia 

NICNAS 2005.)

MDH applied an uncertainty factor of300 in deriving its RfD. That factor includes a "database 

uncertainty" factor of 10, which is not justified given the available data.[FN1: MDH applies a 

database uncertainty factor of 3 on the basis that further studies of neurological and thyroid effects 

are warranted. Neither EPA nor MDH routinely applies additional uncertainty factors for the 

absence of thyroid hormone measurements in toxicological studies. Thyroid hormone 

measurements are not commonly employed in rat toxicology studies, and rats are known to be poor 

models for humans with respect to thyroid effects. There is no suggestion of thyroid disease 

(histologically or clinically) in the PFBS studies to date. MDH expresses a desire for more 

neurological research, but acknowledges the 90-day study of PFBS revealed no neurotoxicity in the 

rats. (See Lieder et al. 2009b, page 47.) The neurobehavioral battery (peripheral neuropathy, motor 

activity and audio-visual) in the 28-day study was negative, except for tail-flick responses in males at 

900 mg/kg/day.

MDH applies an additional uncertainty factor of 3 for the absence of a chronic study. A two-year 

chronic bioassay on PFBS is unnecessary based upon the results of studies to date. The database 

includes a full two-generation reproductive study. (Lieder et al. 2009.) The 2-generation study does 

not show substantially increased sensitivity compared to the 90-day study, and the short half-life of

PFBS suggests that increased sensitivity with more prolonged exposure is not anticipated. 

Considering PFBS' half life of elimination, a two-year study would not be expected to result in 

internal doses any higher than those seen in the 90-day study.] 

MDH's RfD calculation also applied a "Human Equivalent Dose" factor based on the ratio of the 

half-life in human blood to the half-life in male rats -- in effect using an additional safety factor of 

142 to address inter-species extrapolation. Given the human half-life data and the lack of evidence 

of accumulation in humans, such an approach is unsupported. On this basis, MDH arrives at a 

Reference Dose of 0.0014 mg/kg/day -- which is two orders of magnitude lower than a standard 

EPA calculation. EPA, apparently without thorough scrutiny, employs this Minnesota Reference 

Dose to calculate the Health Reference Level for PFBS set out in the Information Compendium 
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supporting the proposed rule. We urge EPA to revisit the issue of a PFBS Reference Dose, lest this 

informal, borrowed calculation become entrenched without critical review.

PFC Terminology 

Finally, EPA has described all six of the PFC compounds as acids, based on commonlyused 

terminology. Technically, however, it is the anionic form which is found in drinking water, and the 

terminology used should reflect that. Thus, for example, we suggest that the list refer to 

perfluorobutanesulfonate ("PFBS"). Each of the PFCs on the list can be described as a sulfonate or 

carboxylate rather than an acid.

Response: Please see response to comment code 36000 Perfluorinated Compounds (PFCs). 

Historically, EPA methods (e.g. acid herbicides, diquat, paraquat) have listed the acid, not the anion. 

Thus, the same was done for EPA Method 537. In addition, EPA believes that it would add 

confusion to do as the commenter suggests since many of the anions do not have CAS numbers. 
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Comment Code: 37000 Viruses

Summary Response to Comments on Viruses: EPA believes that there is great value to having 

small systems perform virus monitoring. EPA understands that the 800 undisinfected GWSs are a 

small subset of the small GWSs in the country. However, selection of 800 PWSs was statistically 

derived to be nationally representative of the sensitive hydrogeology. Most previous virus 

occurrence studies have been performed in disinfected systems. EPA lacked data on virus 

occurrence in undisinfected GWSs in sensitive aquifers and therefore wanted to understand the risk 

from enteric viruses in such systems.

The virus monitoring under UCMR 3 will give EPA an understanding of the exposure risks in 

populations served by over 15,000 undisinfected systems in karst aquifers nationally, by assessing the 

potential contamination of these aquifers to virus contamination. Data collected under UCMR 3 will 

be used to support discussions regarding whether future regulation may be needed for enterovirus or 

norovirus in untreated groundwater. For example, the data collected under UCMR 3 may identify 

wells with pathogen occurrence (either by cell culture or RT-qPCR) and at least one of the assayed 

indicators. EPA anticipates that indicator occurrence will be more frequent when pathogens are 

present as compared with pathogen absence. Based on these results, EPA could consider an 

indicator suite, complementing the total coliform/E. coli methods, as a means for potential 

improved pathogen prediction. 

EPA acknowledges that the particular method has undergone limited validation. However, 

individual elements of the method have been used by many researchers worldwide. ICR method, 

NanoCeram and qPCR have all been used in several waterborne virus studies. The complete method 

(i.e. Method 1615) is published and has undergone thorough peer review by scientists both within 

EPA and outside. The method has also undergone lab validation at EPA and the data support its use 

for List 3 monitoring. The method follows EPA quality assurance guidelines for PCR methods. 

There are built-in quality controls for PCR inhibition, and positive and negative controls to identify 

false negative and positive assays. In addition, EPA is contemplating using initial and ongoing 

positive and negative PE samples that will validate the ability of analysts to perform the method. 

Also, method performance criteria for acceptance of data are integrated into the method. EPA 

believes that the extensive quality control measures built into the method as well as required of 

laboratories performing the analysis will ensure data validity. Sampling will be performed by trained 

EPA contractors. 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 believes that an assessment of whether viruses are present in undisinfected karst or 

sensitive aquifers on a national scale is warranted.

EPA expects that Borchardt's work will be published in a peer reviewed journal in the near future. 

Further, EPA scientists have served on the Project Advisory Committee (PAC) and have 

independently evaluated Borchardt's work and found it to be a sound study with extensive quality 

assurance measures and appropriate statistical analyses incorporated in it.
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Individual Comments

Commenter Name: Anonymous 

Commenter Organization:

Letter ID: 0051

Comment ID: 31624

Comment Code: 37000

Comment: Is it known yet if the virus methods will be RT PCR, or cell culture based methods for 

UCMR3? When are the methods expected to be determined? 

Is this all the testing that will come as a result of the CCL3 list?

Does EPA still plan to test for helicobacter pylori and the other biologicals? 

Response: EPA Method 1615 will be used to monitor for viruses. The peer-reviewed method was 

published in December 2010 (Publication No. EPA/600/R-10/181) and included in the rule docket. 

Under UCMR 3 EPA will monitor for noroviruses using RT-qPCR as there is no cell culture assay 

developed as yet for detecting it. Enteroviruses will be monitored using both cell culture and RTqPCR. EPA will not be testing for any other CCL 3 microbial contaminants in UCMR 3. 

Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31722

Comment Code: 37000

Other EPA Comment Codes and Descriptions: 38100 Chromium-6; 38200 Total Chromium

Comment: 5. Removing Virus Monitoring. CVWD believes including Cr and Cr-6 monitoring on 

the list of 30 contaminants is more timely and beneficial than the proposed monitoring for two 

viruses (Norovirus and Enterovirus). Test methods for these viruses have not been validated and the 

work by Borchardt used to support virus monitoring has not been peer reviewed. CVWD also 

believes the proposed virus monitoring performed at 800 PWS’s serving less than 1,000 persons 

using undisinfected sources producing groundwater from karst or fractured bedrock formations will 

provide occurrence data of limited value that is not representative of most drinking water served in 

the U.S. Removing monitoring for the two viruses will allow the addition of Cr and Cr- 6 

monitoring without exceeding the prescribed limit of 30 contaminants for UCMR monitoring and 

provide more valuable information for future regulatory decisions. 

Response: Most virus-indicator correlation studies have been performed in disinfected systems. 

UCMR 3 monitoring will specifically focus on undisinfected ground water systems. 

Theoretically, this study could be conducted outside the UCMR 3 program, though EPA believes 

that this effort is far bigger and more complex in scope and funding than a research project can 

achieve. Thus EPA believes that the UCMR 3 is the best mechanism. UCMR 3 will provide 

occurrence data; the main idea is that if occurrence (in sensitive and undisinfected systems) is similar 

on a national scale to that found by Borchardt, exposure and health risks are likely to be similar. 
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EPA disagrees that the rationale for conducting virus monitoring under UCMR 3 is weak and 

believes that a national study is warranted based upon the Borchardt data. The virus method EPA is 

using includes all the elements the commenter has suggested except for the multi-laboratory 

validation. However, EPA will be conducting a PT program prior to the monitoring. This will serve 

both as a "multi-laboratory validation" of the method as well as an evaluation of the performance of 

laboratories. Commercial laboratories will be selected based on their performance in a PT study. 

Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Anonymous 

Commenter Organization:

Letter ID: 0039

Comment ID: 31738

Comment Code: 37000

Comment: Glad to see EPA is finally including viruses-about time.

Response: Please see response to comment code 37000 Viruses.

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31764

Comment Code: 37000

Other EPA Comment Codes and Descriptions: 37035 Sampling Methodology - Viruses

Comment: 5. Removing Virus Monitoring. WESTCAS believes including Cr and Cr-6 monitoring 

on the list of 30 contaminants is more timely and beneficial than the proposed monitoring for two 

viruses (Norovirus and Enterovirus). Test methods for these viruses have not been validated and the 

work by Borchardt used to support virus monitoring has not been peer reviewed. WESTCAS also 

believes the proposed virus monitoring performed at 800 PWS’s serving less than 1,000 persons 

using undisinfected sources producing groundwater from karst or fractured bedrock formations will 

provide occurrence data of limited value that is not representative of most drinking water served in 

the U.S. Removing monitoring for the two viruses will allow the addition of Cr and Cr-6 monitoring 

without exceeding the prescribed limit of 30 contaminants for UCMR monitoring and provide more 

valuable information for future regulatory decisions. 

Response: Please see response to comment code 37000 Viruses. 

EPA will monitor for enteroviruses and noroviruses under UCMR 3 as Pre-Screen Testing. Prescreen Testing is designed to address contaminants with analytical methods that are in an early stage 

of development for use at a limited number of systems determined to be most vulnerable to the 

targeted contaminants.
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Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31796

Comment Code: 37000

Comment: C. Virus testing (76 FR. 11719)

DEP would not be subject to Tier 3 virus testing; however we do want to comment on this 

provision. The focus of our comments is not on whether EPA Method 1615 is robust and has been 

appropriately tested for sensitivity, specificity and reliability; rather DEP's comment concerns the 

use of the data. The FR notice states that the objectives of the monitoring program are: "(1) to 

obtain occurrence information to support regulatory determinations for enterovirus and norovirus; 

(2) to gain a better understanding of pathogen indicator and viral co-occurrence; and (3) to gain 

more exposure/health risk information on viruses and indicators." (p. 11724 of FR). While the first 

two objectives might be met for small groundwater systems subject to the study, DEP has 

significance concerns whether the results of the pre-screen, particularly the qPCR molecular

methods for norovirus could be used to meet the third objective. DEP believes that EPA must 

provide greater documentation on how these data can be used for risk assessment purposes and we 

recommend that the final rule notice strike "risk assessment" from the stated goal. The pre-screen 

should help inform whether to conduct more rigorous testing for virus and for controlled studies for 

risk assessment purposes, but this is not an achievable goal, as proposed, under the current UCMR-3 

program.

Response: EPA will monitor for viruses by qPCR based on the finding that qPCR results could be 

statistically correlated to illness in Borchardt's study in Wisconsin. For purposes of UCMR 3 

monitoring, the presence of viral nucleic acid in undisinfected systems indicates contamination of 

these systems by transport of viruses through karst and fractured bedrock hydrogeology. The data 

will therefore help in assessing risk from these viruses in populations served by these systems. 

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31824

Comment Code: 37000

Comment: Pre-screen viruses and indicators 

Under 40 CFR 141.40(a)(2)(ii)(C) and 141.40(a)(3), EPA proposes that systems that are required to 

monitor for enterovirus and norovirus must also collect specified pathogen indicators, like coliform 

samples.

The TCEQ generally supports this requirement as being a sound scientific means to evaluate the 

correlation of total and fecal coliform methods with the actual presence of viruses. 

Response: EPA appreciates your support and has included indicator monitoring. 
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Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31840

Comment Code: 37000

Comment: Removal of Two Contaminants 

EPA requests comments on what contaminant(s) should be removed from the proposed 30 

UCMR3 contaminants if chromium-6 and total chromium were added. Riverside has reservations on 

the inclusion of the two viruses in the proposed UCMR3 chemical list and recommends removing 

norovirus and enterovirus from UCMR3 to incorporate testing for chromium-6 and total chromium. 

The primary reason for excluding these two viruses from UCMR3 List 3 is that the methods that are 

recommended to be used are still under development. In addition, there are significant issues and 

challenges with molecular methods that must be addressed and proven before use in a national 

occurrence survey. Please refer to ACWA's letter for detailed input on this topic. 

Riverside appreciates the opportunity to review and comment on the proposed UCMR3 program. 

Please contact me at (951) 826-5780 if you have any questions regarding our comments, or if I can 

provide additional information. 

Respectfully, Kevin S. Milligan, P.E. Utilities Assistant General Manager - Water

Response: Please see response to comment code 37000 Viruses. 

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31853

Comment Code: 37000

Comment: 8.0 Removal of Two Contaminants 

EPA requests comments on what contaminant(s) should be removed from the proposed 30 

UCMR3 contaminants if chromium-6 and total chromium were added. As discussed in Section 7.1, 

OCWD supports inclusion of total chromium and chromium-6 in UCMR3. OCWD has reservations 

on the inclusion of the two viruses in the proposed UCMR3 chemical list and recommends 

removing norovirus and enterovirus from UCMR3 to incorporate testing for chromium-6 and total 

chromium. Listed below are specific reasons to remove the viruses from List 3, the Pre-Screening 

Testing from UCMR3.

* The two viruses are on List 3, the Pre-Screening list, which uses methods that are still under 

development and will utilize specialized sampling and analytical equipment. Information contained 

in the proposed UCMR3 states enterovirus would be monitored using one method that has two 

detection assays: (1) tissue culture assay using a NanoCeram filter and (2) viral nucleic acid molecular 

method using qPCR. Norovirus would be monitored using qPCR because there are no tissue culture 
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methods available. Information in the preamble does not indicate that the virus methods (tissue 

culture modified with NanoCeram filter or the qPCR molecular methods) been validated in the field 

and evaluated through a meticulous and robust multi-laboratory validation study. Microbial 

molecular methods are very challenging and careful and experienced analysts are required to avoid 

false positives. There are significant issues and challenges with molecular methods that must be 

addressed and proven before use in a national occurrence survey. The preamble does not provide 

any information on who will be collecting virus samples and what type of training will be provided 

to ensure quality assurance procedures are implemented with all aspects of the sample collections 

tasks.

* EPA places strong basis for inclusion of the viruses in UCMR3 based on the Borchardt work, 

which has not been peer-reviewed. However, EPA states it is soon forthcoming. It is unclear how 

EPA prioritized and used a study that has not passed the scrutiny and expert review of a peer review 

to qualify consideration for a national occurrence program (UCMR3). 

* EPA proposes to select 800 groundwater systems that are undisinfected for the Pre-Screening 

monitoring - this is a very focused subset of small groundwater systems and representing a small 

percent of national sources. 

* EPA proposes that the 800 undisinfected groundwater systems are located in karst or fractured 

bedrock...these geologic features are highly vulnerable and susceptible to multiple routes of 

groundwater infiltration, rapid transport, minimal time underground, etc. Given the site selection 

criteria, only specific geologic regions around the nation will be included in the national survey. 

* EPA proposes that the 800 undisinfected groundwater systems serve <1,000 people which limits 

the value of the occurrence data to very small systems and percent of national population. 

* EPA’s site criteria to select highly vulnerable sources located in karst or fractured rock geologic 

settings, undisinfected, and serves less than 1,000 people construes that it is highly probable that 

these systems will likely have virus detections. This then questions the value of the occurrence data 

from these selected vulnerable and susceptible systems to provide meaningful data applicable for 

nationwide occurrence use or projection for use in future UCMR testing.

* The preamble (FR page 11724) state that EPA’s goals are to (1) gain occurrence information to 

support regulatory determinations for enterovirus and norovirus for further evaluation, (2) gain a 

better understanding of the co-occurrence of pathogen indicators and viruses, and (3) gain more 

exposure/health risk information on viruses and indicators. Comments on these goals are 

summarized below. 

- Occurrence information from the focused and limited occurrence survey at highly vulnerable and 

susceptible systems will not provide sufficient information to support a regulatory determination for 

enterovirus and norovirus. A future UCMR program which includes virus monitoring at all sizes of 

PWSs will be needed to obtain national occurrence information for a regulatory determination. 

- Numerous published studies have shown that there are weak correlations of virus occurrence and 

pathogen indicators. 
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- The proposed virus and pathogen indicator monitoring may provide exposure and health risk 

information but similar information could be obtained from focused research studies conducted 

outside the UCMR3 program. 

* EPA's rationale to include these two viruses seem weak and it appears that further focused studies 

in this area are needed before inclusion into a national UCMR program at this time; perhaps 

consideration to include virus monitoring in a future UCMR cycle (List 2 or 3) may be warranted if 

results from focused studies demonstrate (1) the value to assess occurrence in disinfected systems

and not just vulnerable groundwater small systems, (2) virus methods have been validated and have 

successfully passed multi-laboratory robust testing producing consistent high quality and accurate 

results, (3) virus assay and molecular methods have been established as proven analytical tools 

utilized widely in commercial laboratories, and (4) stringent laboratory controls and procedures are 

required to avoid false positive and negatives with the methods. 

Response: Please see response to comment code 37000 Viruses.

EPA agrees that most virus-indicator correlation studies have been performed in disinfected 

systems. UCMR 3 monitoring will specifically focus on undisinfected ground water systems.

Please see response to comment ID 31722 under comment code 37000 Viruses.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31854

Comment Code: 37000

Other EPA Comment Codes and Descriptions: 38100 Chromium-6; 38200 Total Chromium

Comment: * Information gained from the limited, narrow virus focus by monitoring select 800 

small systems using undisinfected groundwater will not provide meaningful data to benefit and 

support the overall UCMR goals to provide information for future regulatory decision-making in 

contrast to the benefits potentially gained by including chromium-6 and total chromium in UCMR3. 

The value gained by testing for chromium-6 and total chromium provides national occurrence 

information that will be meaningful for EPA to determine if regulation may be warranted and far

outweighs the data gathering information for Pre-Screening testing for viruses. 

OCWD appreciates the opportunity to review and comment on the proposed UCMR3 program.

Sincerely,

Yira Namachika Director of Water Quality (714) 378-3281

Response: Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies
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Letter ID: 0077

Comment ID: 31896

Comment Code: 37000

Comment: 8.0 Removal of Two Contaminants 

EPA requests comments on what contaminant(s) should be removed from the proposed 30 

UCMR3 contaminants if chromium-6 and total chromium were added. As discussed in Section 7.1, 

ACWA supports inclusion of total chromium and chromium-6 in UCMR3. ACWA has reservations 

on the inclusion of the two viruses in the proposed UCMR3 chemical list and recommends 

removing norovirus and enterovirus from UCMR3 to incorporate testing for chromium-6 and total 

chromium. Listed below are specific reasons to remove the viruses from List 3, the Pre-Screening 

Testing from UCMR3.

*The two viruses are on List 3, the Pre-Screening list, which uses methods that are still under 

development and will utilize specialized sampling and analytical equipment. Information contained 

in the proposed UCMR3 states enterovirus would be monitored using one method that has two 

detection assays: (1) tissue culture assay using a NanoCeram filter and (2) viral nucleic acid molecular 

method using qPCR. Norovirus would be monitored using qPCR because there are no tissue culture 

methods available. Information in the preamble does not indicate that the virus methods (tissue 

culture modified with NanoCeram filter or the qPCR molecular methods) been validated in the field 

and evaluated through a meticulous and robust multi-laboratory validation study. Microbial 

molecular methods are very challenging and careful and experienced analysts are required to avoid 

false positives. There are significant issues and challenges with molecular methods that must be 

addressed and proven before use in a national occurrence survey. The preamble does not provide 

any information on who will be collecting virus samples and what type of training will be provided 

to ensure quality assurance procedures are implemented with all aspects of the sample collections 

tasks.

*EPA places strong basis for inclusion of the viruses in UCMR3 based on the Borchardt work, 

which has not been peer-reviewed. However, EPA states it is soon forthcoming. It is unclear how 

EPA prioritized and used a study that has not passed the scrutiny and expert review of a peer review 

to qualify consideration for a national occurrence program (UCMR3).

*EPA proposes to select 800 groundwater systems that are undisinfected for the Pre-Screening 

monitoring - this is a very focused subset of small groundwater systems and representing a small 

percent of national sources. 

*EPA proposes that the 800 undisinfected groundwater systems are located in karst or fractured 

bedrock...these geologic features are highly vulnerable and susceptible to multiple routes of 

groundwater infiltration, rapid transport, minimal time underground, etc. Given the site selection 

criteria, only specific geologic regions around the nation will be included in the national survey. 

*EPA proposes that the 800 undisinfected groundwater systems serve <1,000 people which limits 

the value of the occurrence data to very small systems and percent of national population. 

*EPA’s site criteria to select highly vulnerable sources located in karst or fractured rock geologic 

settings, undisinfected, and serves less than 1,000 people construes that it is highly probable that 
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these systems will likely have virus detections. This then questions the value of the occurrence data 

from these selected vulnerable and susceptible systems to provide meaningful data applicable for 

nationwide occurrence use or projection for use in future UCMR testing.

*The preamble (FR page 11724) state that EPA’s goals are to (1) gain occurrence information to 

support regulatory determinations for enterovirus and norovirus for further evaluation, (2) gain a 

better understanding of the co-occurrence of pathogen indicators and viruses, and (3) gain more 

exposure/health risk information on viruses and indicators. Comments on these goals are 

summarized below. 

-Occurrence information from the focused and limited occurrence survey at highly vulnerable and 

susceptible systems will not provide sufficient information to support a regulatory determination for 

enterovirus and norovirus. A future UCMR program which includes virus monitoring at all sizes of 

PWSs will be needed to obtain national occurrence information for a regulatory determination. 

-Numerous published studies have shown that there are weak correlations of virus occurrence and 

pathogen indicators. 

-The proposed virus and pathogen indicator monitoring may provide exposure and health risk 

information but similar information could be obtained from focused research studies conducted 

outside the UCMR3 program. 

*EPA’s rationale to include these two viruses seem weak and it appears that further focused studies 

in this area are needed before inclusion into a national UCMR program at this time; perhaps 

consideration to include virus monitoring in a future UCMR cycle (List 2 or 3) may be warranted if 

results from focused studies demonstrate (1) the value to assess occurrence in disinfected systems

and not just vulnerable groundwater small systems, (2) virus methods have been validated and have 

successfully passed multi-laboratory robust testing producing consistent high quality and accurate 

results, (3) virus assay and molecular methods have been established as proven analytical tools 

utilized widely in commercial laboratories, and (4) stringent laboratory controls and procedures are 

required to avoid false positive and negatives with the methods. 

Response: Please see response to comment code 37000 Viruses and response to comment ID 

31722 under comment code 37000 Viruses.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31897

Comment Code: 37000

Other EPA Comment Codes and Descriptions: 38100 Chromium-6; 38200 Total Chromium

Comment: *Information gained from the limited, narrow virus focus by monitoring select 800 

small systems using undisinfected groundwater will not provide meaningful data to benefit and 

support the overall UCMR goals to provide information for future regulatory decision-making in 

contrast to the benefits potentially gained by including chromium-6 and total chromium in UCMR3. 

The value gained by testing for chromium-6 and total chromium provides national occurrence 
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information that will be meaningful for EPA to determine if regulation may be warranted and far

outweighs the data gathering information for Pre-Screening testing for viruses. 

ACWA appreciates the opportunity to review and comment on the proposed UCMR3 program. If 

you have questions or need further information, please contact me at 916- 441-4545 or ACWA’s 

UCMR3 Workgroup Chair, Nira Yamachika with Orange County Water District, at 714-378-3200.

Sincerely,

Danielle Blacet Senior Regulatory Advocate 

Response: EPA believes that virus monitoring under UCMR 3 will be useful because there are a 

large number of small systems serving untreated water but there is very little information regarding 

virus occurrence in these systems.

EPA will monitor for enteroviruses and noroviruses under UCMR 3 as Pre-Screen Testing. PreScreen Testing is designed to address contaminants with analytical methods that are in an early stage 

of development for use at a limited number of systems determined to be most vulnerable to the 

targeted contaminants.

Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31906

Comment Code: 37000

Comment: Enteroviruses and Noroviruses - The NJDEP agrees with the selection of enteroviruses 

and noroviruses from the Contaminant Candidate List 3 (CCL3) pathogens (USEPA, 2009c; as cited 

in the proposed UCMR3) for inclusion in the monitoring under the UCMR3. 

Noroviruses (listed under the broader group of Caliciviruses in the CCL3) are responsible for 

estimated 93% of all non-bacterial gastrointestinal illness in the U.S (Fankhauser et al, 2002). They 

cause more enteric disease outbreaks than any other virus (Post et al., 2011), have a low infectious 

dose, and have comparatively robust survival capacity in the environment (Parashar et al, 2001).

Enteroviruses (listed as Enterovirus in the CCL3) are a large group of enteric viruses with disease 

endpoints that can be severe (paralysis, aseptic meningitis, myocarditis, encephalitis, and neonatal 

sepsis); the associated less-serious illnesses include conjunctivitis, mouth and throat sores, sharp 

abdominal pain, rashes, fever, and respiratory and gastrointestinal illnesses (Khetsuriani et al, 2006). 

Although no disease outbreaks due to enteroviruses in drinking water have been recorded in the 

U.S. since 1993, the Borchardt study (2008; as cited in the proposed UCMR3) shows that some 

enteroviruses in ground water (GW) may be causing endemic disease.

Response: Please see response to comment code 37000 Viruses.
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Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31912

Comment Code: 37000

Comment: Lab capacity. We calculate that on average, for the 800 selected systems (1600 samples), 

33 facilities and 67 samples will need to be analyzed each month to complete sampling within the 

2013-2015 time frame. In light of our recommendations above (within each pathogen indicator 

group, different labs may be certified to use different assays), it is uncertain whether sufficient

contract lab sampling and analytical capacity for the virus assays and universal pathogen indicator 

assays.

Response: EPA's estimates indicate that there will be sufficient lab capacity for analysis of UCMR 3 

virus samples. EPA will perform the sampling over 3 years in a staggered fashion. Sampling 

contractors will be trained by EPA.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32045

Comment Code: 37000

Comment: Screening Survey - Noroviruses and Enteroviruses AWWA has a general concern about 

the overall usefulness of the data that will be generated by the proposed screening. Surveying a 

broader range of utility source waters for cyanotoxins would be more useful and informative to the 

water systems and EPA than screening for noroviruses and enteroviruses in a relatively small 

number of ground water systems serving a relatively small proportion of consumers (<800,000).

Considering the apparent increase in the frequency of cyanotoxinproducing blooms, this occurrence 

information may have broader public health benefit than enteric virus occurrence data in a few nondisinfected small ground water systems. However, if we accept that enteric viruses are the target of 

this monitoring, a few specific issues with the proposed screening warrant comment.

Response: While EPA agrees that cyanotoxins are a potential concern in drinking water, a robust 

method that would support UCMR monitoring is not yet available. Such a method should perform 

in a broad range of water types including high TOC waters, and be able to identify and quantify 

individual cyanotoxins. For some cyanotoxins, sample cleanup has proven to be particularly 

challenging. EPA is currently performing method development work on analytical and cleanup 

methods for LC/MS/MS analyses of cyanotoxins. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32047

Comment Code: 37000
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37000 Viruses Page 261 of 401

Comment: 9. What are the regulatory and public health implications of detecting viral nucleic acids 

that may indicate contamination at some indeterminate time prior to sample collection and may or 

may not be associated with gastrointestinal illness in the community? 

Response: For purposes of UCMR 3 monitoring, the presence of viral nucleic acid in undisinfected 

systems indicates contamination of these systems by transport of viruses through karst and fractured 

bedrock hydrogeology. Thus the question of whether the virus was infectious or not may be less 

relevant in this case. Data obtained from UCMR 3 monitoring will help assess risk from these 

viruses.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32085

Comment Code: 37000

Comment: What analytical methods are appropriate for norovirus and enterovirus? - Cell culture is 

the only potentially viable strategy for direct detection of infectious enteroviruses. However, MPN 

based on CPE is likely to give highly variable results. PCR is the only method available for 

noroviruses since they cannot be grown in cell culture.

Response: Use of the MPN approach is consistent with the validated ICR virus method. Various 

method alternatives have been discussed among environmental virologists at a 1996 pre-ICR 

meeting in Cincinnati, Ohio; this included using quantal assays with MPN calculations versus using a 

plaque assay to reduce variability. It was the strong consensus that the higher sensitivity achieved by 

quantal assays was important and warranted accepting the variability associated with MPN. EPA 

virologists evaluated currently available analytical methods and determined that this assessment is 

still valid. Since the cell culture aspect of Method 1615 is essentially the same as in the ICR method 

with the exception of the NanoCeram filter, EPA chose to have MPN approach in Method 1615. 

EPA agrees that PCR is the only method available for norovirus detection. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32089

Comment Code: 37000

Comment: What MRLs are appropriate for norovirus and enterovirus? The UCMR3 proposal states 

that MRL is based on volume of water filtered and PCR amplification level but it currently lists the 

MRL for noroviruses and enteroviruses as N/A. 

The LCMRL approach cannot be used to set an MRL for detection of microbes. An assumption 

underlying the LCMRL approach is that the probability of the analyte occurring is a continuous 

function. This is not the case for microbes. We have ample evidence that microbe occurrence is not 

continuous; consequently an alternative approach is necessary.
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Response: Rather than reporting MRLs, analytical laboratories will be required to report positive 

results in terms of concentration per liter and negative results as less than or equal to the detection 

limit. The detection limit is a function of volume filtered and the amount of filter eluate analyzed by 

culture or PCR. 
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January 2012

37010 EPA Method 1615 - Viruses Page 263 of 401

Comment Code: 37010 EPA Method 1615 - Viruses

Individual Comments

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31908

Comment Code: 37010

Comment: Comments on Proposed Methods for Monitoring of Microbiological Contaminants 

The proposed methods as described in the Proposed UCMR3 Rule are satisfactory but incomplete. 

The NJDEP has the following questions, concerns and suggested changes.

Possible alternative explanation of molecular assay results. The virus methods include numerous 

quality control (QC) checks to account for factors such as cell culture contamination, microbe 

and/or nucleic acid cross-contamination, polymerase enzyme inhibition, and nucleic acid probe (and 

entire protocol) specificity/sensitivity/functionality. These controls include negative and positive 

assay controls as well as negative and positive sample preparation controls. For practical reasons, 

there is only a single negative and positive QC sample preparation control for every "batch" of 

samples processed each week.

As an example, in the Francy study (2004; as cited in the proposed UCMR3), replicate samples (2 

samples collected consecutively on the same date) for Hepatitis A virus (HAV) qPCR analysis were 

collected and analyzed for 32 of 169 wells (Table 11; pp.44-50) using a sample processing protocol 

similar to that specified for the UCMR3 (USEPA, 1996; as cited in the proposed UCMR3). For 26 

of these wells, no HAV was detected in either replicate. However, for 3 wells, one of the replicates 

failed the QC checks while the other replicate was negative (false-positives?) and for 2 wells, both 

replicates failed the QC checks (polymerase enzyme inhibition?). For the remaining well, one 

replicate was positive for HAV and the other was negative, which the authors attributed to low or 

intermittent concentration of viruses in the wells. Because the 38 wells examined in this study were 

not all sampled the same number of times, the data can only be analyzed, in an appropriate statistical 

manner, on a per-sample rather than a per-well basis. Including the replicate samples as independent

samples, the overall HAV QC failure rate was 10% (20/201). Although 3⁄4 of this was due to 

polymerase enzyme inhibition (7.5 %; text p.15), 2.5% must have been due either to a false-positive 

result or some other reason. Compare this 2.5% value with the percentage of qPCR-tested samples 

that were positive for Enterovirus (2.4%) and for HAV (2.8%). It is unclear whether the 4 samples 

(of 158, excluding the enterovirus-spiked replicates and samples that failed QC) that were qPCRpositive for Enterovirus or the 5 samples (of 181, excluding the samples that failed QC) that were 

positive for HAV really contained these viruses or were false-positives due to lab contamination. 

The same issue could apply to the enterovirus culture results as well: 2 positive samples (of 93 tested 

[2%], excluding the 6 enterovirus-spiked replicate samples). Depending on the QC and detection 

rate data, a similar argument could be made for some other studies. 
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37010 EPA Method 1615 - Viruses Page 264 of 401

Response: EPA agrees that false positive and negative results have occurred in studies of virus in 

drinking and environmental waters. However, studies such as that by Francy and colleagues used 

conventional PCR that required the handling of highly amplified DNA following PCR. The use of 

qPCR in Method 1615 will greatly reduce the likelihood of false positives. Further, the lack of 

consistency in duplicate samples taken by Francy could mean a high rate of false positive results, or 

could be a result of the difficulties of sampling discrete particles that are present at low 

concentrations. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32046

Comment Code: 37010

Comment: AWWA commends EPA for approving a molecular component as part of EPA Method 

1615. AWWA believes that molecular methods are promising for microbial detection, particularly 

for currently unculturable microbes, and the only way to fulfill this promise is to incorporate them 

into monitoring programs. However, rolling out molecular methods before they have been tested 

and proven in rigorous multi-laboratory validation studies can be counter-productive. In fact, EPA 

recommends the use of inter-laboratory collaborative studies for validating methods that are 

expected to see widespread use or to support regulatory activity.[FN1:EPA Forum on 

Environmental Measurements, 2009. Method Validation of U.S. EPA Microbiological Methods of 

Analysis] A number of concerns regarding application of this methodology are detailed below. What 

is the overall purpose of the proposed virus screening? It is already recognized that the highest rate 

of regulatory microbial violations occur among small systems serving 500 people or less.[FN2:NRC 

(National Research Council) 1997. Safe drinking water from every tap. Improving water service to 

small communities. National Academy Press, Washington D.C.] So, the proposed monitoring is 

likely to be only confirmatory of already accepted knowledge. Monitoring larger systems would 

provide more generally useful information. 

Many published studies demonstrate that most standard microbial indicators do not correlate well 

with enteric viruses. The study that is used in part to support this proposed monitoring showed a 

correlation between qRT-PCR and health outcomes.[FN3: Borchardt, Mark (unpublished), 

Wisconsin Water and Health Trial for Enteric Risks (WAHTER Study). (EPA-HQ-OW-2009-0090-

0023)] However, this same study also questioned the value of collecting indicator occurrence 

information because of the poor correlation between viruses and indicators. Consequently, we 

question the value of collecting indicator data in the proposed screening survey.

These methods should be developed in a manner analogous to the chemical methods. That is to say, 

both a method detection limit and a reporting limit need to be set. In evaluating the detection limit, 

careful consideration should be given to interferences, matrix affects, and other frailties of the 

method. The process for setting the reporting level should include inter-laboratory performance 

comparisons. 

Screening Survey Methodology - Pursuing the proposed screening survey with an analytical method 

that has not been fully validated is not prudent. The following questions should be addressed: 
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37010 EPA Method 1615 - Viruses Page 265 of 401

1. How robust is EPA Method 1615? If it is expected that more than one laboratory will process 

samples, has the entire method been through inter- laboratory Tier 2 validation and is this validation 

available for review?

2. Has the molecular component of the method been through multi-lab validation and is this 

validation data available? Are data available on the efficiency of the nucleic acid extraction 

procedure? How consistent and reproducible is the method when different reagents and instruments 

are used?

3. What were the results of the 4-lab validation of the alternative electropositive filter and will these 

results be published prior to finalizing UCMR3?

4. Although all of the primers and probes were published prior to developing EPA Method 1615, 

they may not have been used as part of a complete validated method. Similarly, performance data is 

available for various components of the method but not for the entire method. What are the rates of 

false-positive and false- negative for EPA Method 1615? 

5. Are sensitivity and specificity data available for review?

6. Who will provide performance evaluation (PE) samples for testing lab proficiency during the 

screening period? 

7. Considering the somewhat subjective nature of determining cytopathic effect (CPE) and the wide 

confidence limits surrounding most probable number (MPN) calculated values, we question the 

appropriateness of this approach. A plaque assay may provide more meaningful enterovirus 

concentrations. 

8. What will be the requirement for a minimum equivalent volume to be analyzed? 

Response: Please see response to comment code 37000 Viruses. EPA proposed the monitoring of 

small, undisinfected ground water systems because there was very little data available on virus 

occurrence in these systems. This data will help EPA is assessing risk from viruses in populations 

served by these systems.

Studies on virus-indicator correlation have been mostly performed on disinfected systems. 

Borchardt's work although significant and performed in undisinfected systems, is not a national 

study. Also, the use of 5 indicators will help us better understand correlation or lack thereof. 

Performance testing and sample analysis will be provided through an EPA contract. The 

requirements for minimum equivalent volume to be analyzed for each analyte are specified in 

Method 1615.
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Comment Code: 37030 Sampling Location - Viruses

Individual Comments

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31825

Comment Code: 37030

Comment: However, as discussed below under sampling location, the TCEQ recommends that 

samples be collected from raw water, rather than at EPs. The intent of the UCMR3 sampling is to 

determine whether viruses occur in wells. Blending multiple wells at an entry point can mask the 

presence of a contaminant in one of the multiple wells. For the same reason, the TCEQ 

recommends using sample locations as close to the well head as possible, not at EPs. 

Response: The purpose of UCMR is to measure contaminant occurrence in drinking water for the 

purpose of determining whether the public is exposed at concentrations of health significance. As a 

result, EPA’s priority is occurrence at the EPTDS and within the distribution system where 

exposure risks are greatest.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32093

Comment Code: 37030

Comment: Is the EPTDS sampling location appropriate for norovirus and enterovirus? - Since 

EPA proposes to monitor only at systems that are nondisinfected systems, the EPTDS is an 

appropriate sampling point. 

Response: EPA agrees that the EPTDS is appropriate for the monitoring of viruses in UCMR 3. 
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37035 Sampling Methodology - Viruses Page 267 of 401

Comment Code: 37035 Sampling Methodology - Viruses

Individual Comments

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31764

Comment Code: 37035

Other EPA Comment Codes and Descriptions: 37000 Viruses

Comment: 5. Removing Virus Monitoring. WESTCAS believes including Cr and Cr-6 monitoring 

on the list of 30 contaminants is more timely and beneficial than the proposed monitoring for two 

viruses (Norovirus and Enterovirus). Test methods for these viruses have not been validated and the 

work by Borchardt used to support virus monitoring has not been peer reviewed. WESTCAS also 

believes the proposed virus monitoring performed at 800 PWS’s serving less than 1,000 persons 

using undisinfected sources producing groundwater from karst or fractured bedrock formations will 

provide occurrence data of limited value that is not representative of most drinking water served in 

the U.S. Removing monitoring for the two viruses will allow the addition of Cr and Cr-6 monitoring 

without exceeding the prescribed limit of 30 contaminants for UCMR monitoring and provide more 

valuable information for future regulatory decisions. 

Response: Please see response to comment code 37000 Viruses.

EPA will monitor for enteroviruses and noroviruses under UCMR 3 as Pre-Screen Testing. Prescreen Testing is designed to address contaminants with analytical methods that are in an early stage 

of development for use at a limited number of systems determined to be most vulnerable to the 

targeted contaminants.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31910

Comment Code: 37035

Comment: Virus sample volumes and pathogen indicator methods and volumes are not specified. 

The method cited for the groundwater virus extraction protocol (USEPA, 1996; as per UCMR3) is 

for source and finished waters from water treatment plants that have surface waters as their source. 

The method specifies a minimum volume of 1500 liters and a maximum volume of 1800 liters for 

finished (treated) waters (and >= 200 but <= 300 liters for source waters). The finished water 

volumes for groundwater samples have not been specified. Francy et al. (2004) processed 2000-liter 

volumes for their study. Lambertini et al (2008; as cited in the proposed UCMER3) sampled 

between 1139 and 1821 (median 1431) liters in their study. Borchardt (2008) sampled between 76 

and 2067 (mean 860) liters in their study (slide 25). Gibson and Schwab (2011) processed 100 liters 
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37035 Sampling Methodology - Viruses Page 268 of 401

(using ultrafiltration). Whatever volume is selected, for the best dataset the volume should 

standardized (identical) for all samples.

In addition, sample methods and volumes for the pathogen indicators are not specified. It is unclear 

whether "standard methods" should be used and, if so, if the sample volumes should be those 

specified in those methods. 

There is more than one type of "standard method" which can be used to detect some of the 

pathogen indicators such as total coliform (TC) bacteria, E. coli (EC) and enterococci (ENT)(Eaton, 

et al, 2005). If standard methods are to be employed, only one type of assay should be specified for 

each of these pathogen indicators. This is because different respective TC, EC, and ENT assays 

have different detection rates. They have different detection rates because they are detecting 

different populations of the respective bacterial groups (Atherholt et al, submitted; Kinzelman et al, 

2003). A superior dataset will be created if just a single, standard assay is specified for each pathogen 

indicator. 

Also, if large volumes will be sampled for viruses and small volumes will be sampled for pathogen 

indicators, then the sentence containing the second objective of virus monitoring needs to be reworded. The second objective (page 11719, column 1) reads "...and to gain a better understanding of 

the co-occurrence of pathogen indicators and viruses." If hundreds or a thousand or more liters will 

be sampled for viruses and 100 ml will be sampled for pathogen indicators, then this sentence 

should be changed to read "...and to gain a better understanding of the co-occurrence of pathogen 

indicators and viruses acknowledging that the volume of water analyzed for viruses is much larger 

than the volume analyzed for pathogen indicators." A similar sentence regarding the second 

objective, on page 11724, column 3, would also need to be re-worded. 

A number of investigators have already established that, when small (100 ml) volumes are analyzed 

for pathogen indicators using standard, culture methods, and large volumes (see above) are analyzed 

for HEV, some groundwater samples will show the presence of HEV in the absence of pathogen 

indicators (some of these studies are cited on page 7 in Francy et al., 2004). If studies to detect HEV 

collect large sample volumes and use sensitive molecular assays, it is unclear why identical sample 

volumes and methods are not also used to detect pathogen indicators. Molecular assays for at least 

some of the pathogen indicators exist. Evaluation of both pathogen indicators and HEV from 

equivalent sample volumes would address the second objective from the UCMR3 (quoted above). 

The reason for this disparity in sample volumes used is 1) the existing "standardized" pathogen 

indicator tests are quick, easy and inexpensive; 2) the volumes for these tests are specified at 100 ml 

for regulatory purposes (e.g., Eaton et al, 2005); and 3) large volumes must be sampled to detect the 

very low levels of potentially-infectious HEV. It is acceptable to analyze large sample volumes (and 

also to use extremely sensitive analytical methods such as qPCR) to detect HEV in groundwater but 

it is not acceptable to say that HEV, when detected, were detected in the absence of pathogen 

indicators when such disparate sample volumes and test methods are used. 

The volumes specified in the standard methods for the pathogen indicators are 100 ml or less 

because these methods were never intended to be used for groundwater. These tests were developed 

to monitor surface waters (lakes, rivers, recreational waters, shellfish harvest waters, wastewaters). 

Pathogen indicator concentrations (e.g., total coliform bacteria, E. coli, enterococci) in surface 

waters are such that 100 ml (or less) is a suitable and convenient volume for reliable quantitation in 
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37035 Sampling Methodology - Viruses Page 269 of 401

most cases. For pathogen indicator monitoring of groundwater, 1-liter volumes have been advocated 

for "routine" monitoring (Fujioka & Yoneyama, 2001; Atherholt et al, 2003) and greater volumes

and molecular methods can be employed in a research setting.

Of course, once the volume for a pathogen indicator assay exceeds 1 liter, the assay is no longer 

"quick, easy and inexpensive." Also, some of the standard methods (e.g., chromogenic substrate 

assays such as SM9223B, and most-probable- number assays such as SM9221F) are not designed to

assay volumes other than 100 ml. However, membrane filtration assays (e.g., SM9222B, SM9222G, 

EPA Methods 1603, 1604, and 1103.1) can easily handle 1-liter GW volumes (in fact, volumes from 

100 to 1000 ml are specified for drinking water samples for non-regulatory purposes; Eaton et al, 

2005) and larger volumes can be sampled (e.g., Knappett et al, 2011) and molecular methods can be 

used to detect pathogen indicators the same way HEV are analyzed. When trying to determine the 

co-occurrence of viruses and pathogen indicators, the NJDEP strongly recommends using 

equivalent sample volumes and test methods. Groundwater sample volumes should be at least 1-liter 

(in which case a different virus sample extraction protocol should be specified) but preferably more.

Response: Method 1615 recommends a sampling volume of 1800 L but specifies a minimum 

volume of 1500 L. EPA intends to specify through contractual language, fixed volumes as described 

in the respective methods for virus and indicator monitoring. 

EPA intends to use only one type method each for TC/EC, Coliphage/enterococci and aerobic 

spores monitoring. 

EPA acknowledges that ideally, testing of similar volumes of water (for pathogen and indicators) 

would help in pathogen - indicator co-relation study. However, as stated by the reviewer, large 

volumes of water for indicator monitoring will be impractical for a large and complex operation 

such as UCMR 3 implementation. Historically, monitoring volumes for indicators and pathogens 

have been different because indicators are expected to be present in much larger concentrations than 

pathogens. Indicator methods have a requirement for 100 ml volume of distribution system 

(finished) water under the Total Coliform Rule. EPA believes that 100ml volume will be sufficient 

for the purpose of UCMR 3 indicator monitoring. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32048

Comment Code: 37035

Comment: Screening Survey Sampling and Lab Capacity - It is not clear that the proposed survey 

structure is appropriate to inform regulatory decision making. A number of questions regarding the 

proposed approach should be addressed prior to initiating data collection: 

1. Is the proposed sampling strategy of two samples per system over a 12 month period sufficient to 

capture variability in occurrence? It seems unlikely; wouldn’t more frequent sampling of fewer 

systems be more informative considering the known variability in microbial occurrence?
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37035 Sampling Methodology - Viruses Page 270 of 401

2. Since only a few laboratories will be able to analyze samples due to limited cell culture and 

molecular-qualified facilities, will collection of the 1,600 samples (800 systems, twice during a 12 

month period) be staggered or will all samples be collected and analyzed within the same timeframe?

3. Is current or anticipated laboratory capacity sufficient to analyze this number of samples? 

4. More information on the logistics of sample collection should be provided. Who will collect 

samples and how will they be collected?

5. If water samples are filtered on site, will all of the 800 systems be able to perform this sampling or 

will already trained contractors be employed?

6. Will training be provided and if so, who will provide training? This is particularly important when 

considering the variation in virus retention based on flow rate, as described in the method. 

Consistent procedures for sample collection are critical if comparisons are to be made between 

samples.

Response: EPA statistically evaluated both options; more sampling with less systems and less 

sampling with more systems and concluded that there was more value in sampling more systems 

fewer times. EPA will perform the sampling over 3 years in a staggered fashion and anticipates that 

there will be sufficient lab capacity to perform the analysis. Sampling contractors will be trained by 

EPA.
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Comment Code: 37050 Borchardt Data - Viruses

Individual Comments

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31815

Comment Code: 37050

Comment: Regarding the Borchardt data and the merits of the proposed UCMR 3 virus 

monitoring, the MDH asks for clarification of the statement on page 11719, section 2(a): "Of 

particular concern are PWSs in areas with karst or fractured bedrock, as well as in noncommunity 

water systems." Is this comment meant to indicate that all noncommunity PWSs pose equivalent 

risks to karst geology?

We have followed Dr. Borchardt’s work quite closely and believe there is much that can be learned 

and built upon from his data. However, as with the viral data that was gathered prior to the Ground 

Water Rule (GWR), we are concerned about the use of data collected only from community PWS 

study(s) and then being applied to noncommunity systems. There are significant differences between

contaminant sources of the Borchardt study (sanitary sewer line density and well pumping rates) that 

are not typical of noncommunity PWSs. During the development of the GWR (in consultation with 

U.S. EPA and M. Abbaszadegan), Minnesota collected virus samples from noncommunity public 

water supplies as well as bacteriological indicators total coliform, E. coli, bacteriophage, and

enterococcus. We did not observe the same percentage of viral or bacteriological detects as those 

observed at the national level. We have also conducted a number of follow-up studies and would be 

happy to share any of our findings. We recommend re-creating the Wisconsin Water and Health 

Trial for Enteric Risks (WAHTER Study) for noncommunity PWSs. 

Response: UCMR 3 will be monitoring both community and non-community ground water 

systems.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31882

Comment Code: 37050

Other EPA Comment Codes and Descriptions: 22000 Pre-Screen Testing

Comment: Page 11719: "EPA welcomes comments on the Borchardt data and on the merits of the 

proposed UCMR 3 monitoring." 

We believe it is critical that EPA work to verify the implications of the Borchardt study whether 

through UCMR3 or by other means. If traditional surrogate indicators of viral contamination cannot 

be relied upon, it calls into question the presumptions in the Ground Water Rule and, in that case, 
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the implications for ground water systems are significant. (However, while most states supported 

including viruses in UCMR3, at least one state questioned the value of including them, due to 

questions about their health significance in the drinking water context.) Conducting virus monitoring 

on a routine basis for compliance with a rule is not, in our judgment, a feasible option for small 

ground water systems at this juncture. EPA needs to have a valid scientific basis for any changes in 

the regulation of viruses. In conducting monitoring under UCMR3, the target group is small 

systems. Monitoring for viruses only at systems with a population of less than 1,000 could be 

construed to imply that undisinfected groundwater systems serving over 1,000 are not at risk. There 

are many systems over this population threshold that don’t disinfect and could be equally vulnerable. 

Under the proposed monitoring regime for UCMR3, we won’t know how many larger systems, both 

the undisinfected, and even those that disinfect, have viruses in their drinking water. We recommend 

that EPA expand its monitoring for these viruses to include, in the potential sample pool, any 

systems that meet the undisinfected ground water criteria, regardless of size. Another complication 

with the List 3 Pre-Screen Testing is the geologic setting of the systems to be sampled. The 

discussion regarding the viruses indicates that they are proposed to be monitored for in 

undisinfected PWSs located in sensitive hydrogeological areas. This is much like the UCMR1 where 

states were to indicate which systems were most vulnerable. In this proposal, there is no indication 

of how these systems are to be identified. States do not necessarily have the resources to determine 

which systems are most vulnerable, and may not want to be responsible for choosing such systems. 

Response: EPA will take the lead in identifying the vulnerable systems and coordinate with 

partnering states to review preliminary selections.

To maintain a manageable sample size (800 systems) EPA is restricting the virus study to the most 

vulnerable systems, those very small systems serving less than 1,000 customers, that are located in an 

area of vulnerable geology and that do not disinfect. 

Please see response to comment code 22000 Pre-Screen Testing.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31909

Comment Code: 37050

Comment: The association of higher enterovirus and norovirus concentrations with higher rates of 

GI illness in the Borchardt study (2008) is compelling and would argue against inadvertent lab 

contamination. However, this conclusion is based primarily on a few high-concentration, viruspositive samples (enterovirus, 109 of 1204 samples [9%], median = 0, mean = 0.8, max = 851 

genome copies/L; norovirus G1, 51 of 1204 samples [4%], median = 0, mean = 0.6, max = 116

copies/L). Are the Borchardt means based on all samples or just the positive samples? The error 

bars surrounding a mean generated from 1204 samples, when 90-95% or more of the data is 

censored, would be such that the value would be meaningless. Also, children are more susceptible to 

enterovirus infections than adults (Post et al, 2011) but adults were found to be more susceptible in 

the Borchardt (2008) study. Thus, their results should be interpreted with caution. 

Response: Please see response to comment code 37000 Viruses.
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Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31913

Comment Code: 37050

Comment: Targeting wells located in "sensitive hydrogeological areas" for virus sampling. There is 

already ample evidence in the literature that HEV can be found in karst and fractured bedrock 

settings (e.g., Francy, 2004; Johnson et al, 2011; Borchardt, 2008; Goeppert and Goldscheider, 

2011). Although the proposed UCMR3 states that most of the wells in which viruses were detected 

in the Borchardt (2008) study were not located in sensitive hydrogeological settings (p. 11719,

column 1) the geological data provided by Borchardt (slide 13) are in most cases what we consider 

to be "sensitive."

Borchardt (slide 63) states that such facilities should be disinfecting and we agree with this 

statement. We believe strongly that, based on sampling of a large population of private wells for 

pathogen indicators (Atherholt et al, submitted) all wells in sedimentary rock (limestone, dolomite, 

sandstone, siltstone, mudstone, conglomerates, shale, argillite) are vulnerable and should disinfect. 

What is uncertain is whether or not wells located in the coastal plain, which have a very low level of 

fecal coliform or E. coli contamination, are subject to HEV contamination (Atherholt et al, 

submitted). Are these geological strata filtering out bacteria but allowing viruses to reach the GW?

Response: EPA appreciates the comments, but notes that the suggestions are outside of the 

purview of the UCMR program. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32094

Comment Code: 37050

Comment: 6. The Borchardt data and on the merits of the proposed UCMR 3 monitoring. 

Borchardt’s data appear to be sound.[FN18: Borchardt, Mark (unpublished), Wisconsin Water and 

Health Trial for Enteric Risks (WAHTER Study). (EPA-HQOW- 2009-0090-0023).] However, this 

data is essentially single lab data-AWWA has not found independent corroboration in another study. 

Response: Virus findings in the Francy study in Michigan were consistent with the WAHTER 

study. 
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Comment Code: 37300 General Indicators

Individual Comments

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31883

Comment Code: 37300

Comment: As a part of the Pre-Screen Testing, EPA is also collecting samples for pathogen

indicators such as total coliforms, E. coli, bacteriophage, Enterococci and aerobic spores. We believe 

these are good companion samples to take to help verify the validity of Dr. Borchardt’s work and of 

indicators in general. However, these are more than just meta data for the virus sampling such as

parameter like temperature or pH and could constitute additional contaminants that are being 

monitored. This calls into question the total number of contaminants monitored under UCMR3 and 

whether additional contaminants would need to be dropped to support the additional indicators 

being collected for Pre- screen Testing.

Response: EPA’s Office of General Counsel has concluded that monitoring for indicators is not 

subject to the statutory limit on the number of unregulated contaminants. The indicators are being 

monitored to provide correlative information related to enterovirus and norovirus monitoring, much 

like pH, turbidity, free chlorine, etc. are measured concurrent with chemical monitoring. Therefore 

there is no need to drop additional contaminants from the monitoring list. 
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Comment Code: 37400 Aerobic EndoSpores

Individual Comments

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31911

Comment Code: 37400

Comment: It is not clear why aerobic spores will be monitored as pathogen indicators. Anaerobic 

spores (Clostridium perfringens) are a more fecal-specific indicator than are aerobic spores 

(presumably from soil-borne Bacillus spp.), but it has been shown that anaerobic spores are poor 

indicators of fecal contamination compared to other indicators such as coliform or enterococcus 

bacteria (Francy et al, 2000 & 2004; Atherholt et al, 2003; Butscher et al, 2011).

If aerobic spores are to be employed, not as a fecal indicator, but as an indicator of surface water 

influence, we suggest monitoring for heterotrophic plate count (HPC) bacteria instead. There is 

evidence that HPC counts in a well significantly above average for all sources could serve as a trigger 

for fecal indicator monitoring, but the data was limited and a definitive conclusion could not be 

drawn (Atherholt et al, 2003). Other investigators have shown that HPC may be a useful GW 

indicator (Butscher et al, 2011, Goeppert and Goldscheider, 2011). HPC testing is also very useful 

for QC purposes including negative control counts and for the ease of determining quantifiable and 

reproducible (similar) counts in replicates of field samples.

Response: EPA does not propose to assay anaerobic spores in UCMR 3. 

It has been established that enteric viruses and especially, some enteroviruses, are very long lived in 

ground water at typical ground water temperatures, perhaps surviving for 1-3 years (e.g., Long-Term 

Inactivation Study of Three Enteroviruses in Artificial Surface and Groundwaters, Using PCR and 

Cell Culture - A. M. de Roda Husman, W. J. Lodder, S. A. Rutjes, J. F. Schijven, and P. F. M. Teunis 

- Applied and Environmental Microbiology, February 2009, p. 1050-1057, Vol. 75, No. 4). Aerobic 

spores are proposed as an indicator under UCMR 3 because the spore form of common soil bacteria 

are long-lived under many environmental conditions, including, it is believed, in ground water. The 

total coliform and the heterotrophic plate count (HPC) bacteria, as vegetative cells rather than 

spores, are not believed to be particularly long lived in ground water, as compared with the enteric 

viruses. In addition, aerobic spores have been shown to be mobile in porous media ground water, 

and have become established as the most widely used surrogate measure of pathogen subsurface 

transport efficiency in porous media (e.g., sand aquifers, EPA LT2 Enhanced Surface Water 

Treatment Rule Toolbox Guidance Manual, April 2010). EPA believes that, in many or most aquifer 

types, bacterial spores may be equally as or more mobile in the subsurface as compared with 

vegetative cells. Because aerobic spores are long-lived and also mobile in the subsurface, EPA 

believes that they might serve as one or part of group viral indicator microorganism.
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Comment Code: 38000 Other Contaminants

Summary Response to Comments on Other Contaminants: EPA used a stepwise prioritization 

process to identify potential UCMR 3 contaminants. As a first step, the agency reviewed the recently 

promulgated CCL 3 list and the "pre-CCL" contaminants considered in the development of CCL 3. 

Under the CCL 3 process, the agency considered the best available data and information on health 

effects and occurrence to evaluate 7,500 unregulated contaminants. The final CCL 3 is comprised of 

104 chemicals or chemical groups and 12 microbiological contaminants that were selected through a 

data-driven process that considered adverse health effects (potency and severity) and occurrence 

(prevalence and magnitude). The list includes pesticides, biological toxins, disinfection byproducts, 

chemicals used in commerce, and waterborne pathogens (74 FR 51850, October 8, 2009). EPA used 

CCL 3, along with additional sources of information about other emerging contaminants of 

potential concern, to establish an initial list of approximately 150 potential UCMR 3 contaminants. 

The proposed contaminant list for UCMR 3 was further pared down as follows: (1) contaminants 

with no currently available methods, or methods that would not be ready in time for UCMR 3 

monitoring were eliminated; and, (2) those contaminants included in UCMR 1 or UCMR 2 

monitoring were also eliminated from inclusion. This narrowed list of fewer than 35 analytes was 

further considered by an EPA and State working group, and was prioritized using health effects data 

and other critical endpoints, to arrive at a proposed list of 30 analytes. EPA published this proposed 

list in the Federal Register on March 3, 2011 (76 FR 11713). Further information on this 

prioritization process and on the health effects and occurrence data EPA used to select the chemical 

analytes for UCMR 3 is contained in "UCMR 3 Contaminants - Information Compendium". After 

receiving and considering public comments on the proposed list, EPA has added chromium-6 to the 

list of unregulated contaminants, and removed sec-butylbenzene and n-propylbenzene. Pursuant to 

Section 1445(a)(1)(A) of SDWA, as amended in 1996, EPA is also requiring PWSs to monitor for 

total chromium concurrent with all chromium-6 monitoring. 

EPA recognizes that cyanotoxins would be found more commonly and at higher concentrations in 

source water than in drinking water. However, EPA's priority under UCMR is to monitor drinking 

water at locations, such as EPTDS and within the distribution system, that are most relevant to 

actual exposure. While EPA agrees that cyanotoxins are a potential concern in drinking water, a 

robust method that would support UCMR monitoring is not yet available. Such a method should 

perform in a broad range of water types including high TOC waters, and be able to identify and 

quantify individual cyanotoxins. For some cyanotoxins, sample cleanup has proven to be particularly 

challenging. EPA is currently performing method development work on analytical and cleanup 

methods for LC/MS/MS analyses of cyanotoxins. 

Individual Comments

Commenter Name: Debra Hahn

Commenter Organization:

Letter ID: 0040

Comment ID: 31601

Comment Code: 38000
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Comment: Additional contaminants I support future water analysis, testing for cholera, enteric 

bacteria, rota- and polioviruses, intestinal protozoans, Ascaris (intestinal roundworms), Dracunculus 

medinensis (Guinea worm), Trichuris trichiura (whipworm), Enerobiious vermicularis (pinworm), 

fluorides, heavy metals, nitrates and synthetic chemicals in the interests of global health as

summarized in the Baytel Associates report, "Proposed Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR3) for Public Water Systems". The 12 chemicals listed in this report 

are critical drinking water contaminants needing elimination for producing maximal health effects 

worldwide. 

I studied medical transcription at Northern Virginia Community College in 2001 under David J. 

Munch, PhD, a current EPA employee. I attended the Washington Hospital Center and Wichita 

State University medical technician programs. I earned a bachelor of arts degree in biology and 

MacMurray College in Jacksonville, Illinois. One of my physicians is Aaron Fields, D.O., who 

studied and completed the medical technician program at Wichita State University.

Thank you. 

Sincerely yours,

Debra Diane Hahn 1829 N. Smarsh Lane Wichita, KS 67212-1471 316-200-8662

debbie.hahn@cox.net 

Response: EPA appreciates your comment and input for contaminants for future inclusion in the 

UCMR program. Please see response to comment code 38000 Other Contaminants. 

Commenter Name: G. Dubas

Commenter Organization:

Letter ID: 0045

Comment ID: 31606

Comment Code: 38000

Comment: I suggest replacing one of the many hormones on the proposed list with Triclosan. 

Three Federal agencies are concerned about the ubiquitous Triclosan, or 2,4,4'-Trichloro-2'-

hydroxydiphenyl ether and 5-Chloro-2,2,4'- dichlorophenoxy phenol. It is unknown what, if any, 

level is safe for human consumption and it should be monitored under the Safe drinking Water Act. 

This EPA-regulated pesticide is used on permeable and semi-permeable membranes inside mouths 

(toothpaste), and on skin (anti-bacterial hand soaps). Triclosan in biosolid sludge is applied to food 

crops. It's affect on soil microbes and soil fertility is unknown. 49% of American crops are fertilized

with human biosolid sludge. A recent study showed it persisted in sludge-amended soil samples for 

858 days where it could be transformed into an even more persistent degradate, or become 

mineralized. (Walters, E., et al., Occurrence and loss over three years of 72 pharmaceuticals and 

personal care products from biosolids-soil mixtures in outdoor mesocosms, Water Research (2010), 

doi:10.1016/j.walters.2010.07.051) Main uses are toothpaste, deodorants, shaving creams, 

mouthwashes, hand sanitizers, and cleaning supplies. It is infused into many "anti-bacterial" 

consumer products, such as kitchen utensils, toys, bedding, socks, and trash bags. A closer look at 

the FDA, USGS and CDC websites produced the following information: 
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According to the CDC, this chemical was found in the urine of 75% of the people they tested 

(Antibacterial Household Products: Cause for Concern, Stuart B. Levy (Presentation from the 2000 

Emerging Infectious Diseases Conference in Atlanta, Georgia) 

http://www.cdc.gov/ncidod/eid/vol7no3_supp/levy.htm). 

Emerging superinfections and antibacterial resistance may be exacerbated by the unnecessary use of 

this chemical in personal care and household products (CDC Factsheet, 

http://www.cdc.gov/exposurereport/Triclosan_FactSheet.html.). With bugs such as VRE and 

MRSA, we need stay vigilant about these mounting threats to our immune systems.

The USGS has found triclosan in 30% of US streams, and one of the most common contaminants 

in Colorado’s urban streams, forested streams, domestic and municipal wells since it isn't all being 

removed in the wastewater treatment process (USGS Factsheet 2004-3127, January 2005, 

Wastewater Chemicals in Colorado’s Streams and Ground Water, by Lori A. Sprague and William A. 

Battaglin, http://pubs.usgs.gov/fs/2004/3127/pdf/FactSheet.pdf.) It bioaccumulates and can be 

toxic to aquatic organisms and decrease algal diversity in streams. It alters hormone regulation in the 

American bullfrog. 

The FDA concludes that soaps containing triclosan are no more effective than soaps without 

triclosan. (FDA Consumer Update, Triclosan, What Consumers Should Know, April, 8, 2010,

http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm205999.htm) Chlorinated dioxin and 

chloroform, known human health hazards, are created when chlorinated tap water mixes with 

triclosan. 

Response: EPA did investigate the inclusion of triclosan in UCMR 3. However, the agency was 

unable to identify an analytical method that would provide the desired data quality and sensitivity. 

EPA is continuing analytical methods development for triclosan and other chemicals of potential 

interest for future monitoring.

Please see response to comment code 38000 Other Contaminants.

Commenter Name: Scott Nally

Commenter Organization: Ohio Enviromental Protection Agency 

Letter ID: 0046

Comment ID: 31607

Comment Code: 38000

Comment: Please consider the attached comments on the proposed UCMR 3 for Public Water 

Systems. Feel free to contact Beth Messer at Ohio EPA, (614) 644-2752 with any questions 

Water Docket U.S. Environmental Protection Agency Mail Code 41 01T 1200 Pennsylvania Ave., 

NW. Washington, DC 20460 

Attention Docket ID No. EPA-HQ-OW-2009-0090

Re: Ohio's comments on proposed UCMR 3 for Public Water Systems 
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Ohio EPA submits the following comments on 40 CFR Parts 141 and 142: National Primary 

Drinking Water Regulations: Revisions to the Unregulated Contaminant Monitoring Regulation 

(UCMR 3) for Public Water Systems; published March 3, 2011. Ohio EPA appreciates the 

opportunity to provide comments on the proposed rule revisions.

Cyanotoxins 

Ohio EPA recommends cyanotoxins, or at least microcystin, be included in UCMR 3. The 

Contaminant Candidate List 3 (CCL 3) included three cyanotoxins for consideration: anatoxin-a, 

microcystin-lR, and cylindrospermopsin. Cyanotoxins are known to have human health effects, 

especially for sensitive populations. During 2010, Ohio received 60 reports of human illness 

associated with cyanotoxins, with 40 being classified as probable. We also received 9 reports of pet 

illness, with 7 classified as probable and 5 dog deaths. These reports were linked to recreational 

exposures at lakes around the state, including the Western Basin of lake Erie and 6 inland lakes.

However, it is challenging to determine the risk posed by cyanotoxins from drinking water 

exposures, as only limited drinking water occurrence data is currently available. There is a need for 

the comprehensive collection of occurrence data that can be achieved through UCMR 3.

Analytical methods are available for cyanotoxins, including ELISA, LC/MS/MS and HPLC. The 

ELISA method for microcystin has recently been verified by Battelle's Environmental Technology 

Verification (ETV) program.

If it is not feasible to include cyanotoxins, or at least microcytin, in UCMR 3, we recommend that 

U.S. EPA proceed with collection of occurrence data via another mechanism and does not wait for 

UCMR4.

Response: Please see response to comment code 38000 Other Contaminants.

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31619

Comment Code: 38000

Other EPA Comment Codes and Descriptions: 31000 Hormones

Comment: To make room for Chromium-6, CTDPH suggests removing one of the following 

contaminants: 

3) Estrogenic and androgenic: hormones seem to have occupied 7 spots on the list. One of those 

could be removed to make room for Chromium, and possibly use bisphenol A in substitution to 

another hormone on the list. 

Response: Please see response to comment codes 31000 Hormones and 38100 Chromium-6. 
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Bisphenol A is not under consideration as a contaminant for monitoring in UCMR 3 because there 

is currently no appropriately validated, robust analytical method available. EPA will consider 

Bisphenol A for future monitoring. 

Commenter Name: Patrick Carroll

Commenter Organization: Office of Water Quality, Drinking Water Branch, Indiana Department 

of Environmental Management (IDEM) 

Letter ID: 0056

Comment ID: 31639

Comment Code: 38000

Comment: The Indiana Department of Environmental Management, Office of Water Quality,

Drinking Water Branch recommends the inclusion of cyanotoxins in UCMR 3. Three cyanotoxins 

were listed in the Contaminant Candidate List 3 (CCL 3), anatoxin-a, microcystin-LR and 

cylindrospermopsin, and we recommend these be included. Cyanotoxins are present in our State's 

source waters and are known to have human health effects. We have worked with our State's largest 

drinking water utility to minimize any potential hazard posed by cyanotoxins in the drinking water 

served by this system. It is challenging for us to determine the actual risk posed by cyanotoxins 

because only limited information is currently available. Analytical methods are available for the 

quantification of cyanotoxins in drinking water and source water. Thank you for the opportunity to 

comment

Response: Please see response to comment code 38000 Other Contaminants.

Commenter Name: Wenonah Hauter 

Commenter Organization: Food and Water Watch

Letter ID: 0061

Comment ID: 31652

Comment Code: 38000

Comment: Triclosan and Toxic By-products 

FWW would like to use these comments as an opportunity to request the addition of triclosan, and 

its’ degradates, to the UCMR3. Triclosan is an antibacterial pesticide common in pharmaceutical and 

personal care products. The EPA is currently reviewing our Petition for a Ban on Triclosan; docket 

number: EPA-HQ-OPP-2010-0548.

Since its incorporation into consumer products in the 1960’s, triclosan has been found to 

accumulate in drinking water, surface water, sewage sludge, algae, fish, earthworms, dolphins and 

humans. [FN1: Snyder SA. Occurrence, treatment, and toxicological relevance of EDCs and 

pharmaceuticals in water. Ozone: Science and Engineering. 2008 Jan-Feb; 30: 65-69.] [FN2: Xie Z, 

Ebinghaus R, Floser G, Caba A, Ruck W. Occurrence and distribution of triclosan in the German 

Bight (North Sea). Environmental Pollution. 2008; 156: 1190-1195.][FN3: Fang JL, Stingley RL, 

Beland FA, Harrouk W, Lumpkins DL, Howard, P. Occurrence, efficacy, metabolism and toxicity of 

triclosan. Journal of Environmental Science and Health. 2010 Sept; 28(3): 147-171.][FN4: Halden 

RU, ed. Contaminants of Emerging Concern in the Environment: Ecological and Human Health 
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Considerations. Kinney CA, Furlong ET, Kolpin DW, Zaugg SD, Burkhardt MR, Bossio JP, Werner 

SL. Chapter 14: Earthworms: Diagnostic Indicators of Wastewater Derived Anthropogenic Organic 

Contaminants in Terrestrial Environments. 2010; 297-317.] As stated in the petition, EPA’s 

continued registration of triclosan sets the stage for a violation of Safe Drinking Water Act (SDWA).

In addition to its association to antibiotic resistance and endocrine disruption, research has shown 

that triclosan breaks down into a suite of four dioxins. The EPA characterizes dioxins, "as likely to 

be human carcinogens and are anticipated to increase the risk of cancer at background levels of

exposure." In 2010, University of Minnesota scientists found that the four dioxins derived from 

triclosan had risen as much as 300 percent during the last 30 years, while levels of all other dioxins 

have dropped by up to 90 percent.[FN5: Buth JM, Steen PO, Sueper C, Blumentritt D, Vikesland PJ, 

Arnold WA, McNeill K. Dioxin photoproducts of triclosan and its chlorinated derivatives in 

sediment cores. Environmental Science and Technology. 2010. 44: (12); 4545-4551]

Because the EPA is reviewing this chemical, by way of our petition, this seems a perfect time to add 

triclosan, and its related suite of dioxins, to the UCMR3 list in order to gain a clear picture of its 

presence in the drinking water supply. 

In closing, applaud the EPA for implementing the UCMR program and providing national 

occurrence data in order to determine if a contaminant occurs at a frequency and concentration that 

would be a public health. The addition of PFOA to the UCMR3 is laudable. But, we strongly urge 

the agency to use its authority under the SDWA to include triclosan and its’ suite of dioxin byproducts to the UCMR3 list.

Sincerely,

Wenonah Hauter Executive Director

Response: Please see response to comment ID 31606 in comment code 38000 Other 

Contaminants. 

Commenter Name: Liane J. Shekter Smith

Commenter Organization: State of Michigan Department of Environmental Quality (DEQ)

Letter ID: 0086

Comment ID: 31711

Comment Code: 38000

Comment: Attached is Michigan’s comments on proposed revisions to the Unregulated 

Contaminant Monitoring Regulation for Public Water Systems published March 3, 2011.Thank you!

Liane J. Shekter Smith, P.E., Chief Resource Management Division Michigan Department of 

Environmental Quality 517-373-9523

April 29, 2011 Water Docket U.S. Environmental Protection Agency Mail Code 4101 T 1200 

Pennsylvania Avenue, NW Washington, DC 20460 

ATTENTION: Docket ID No. EPA-HQ-OW-2009-0090
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SUBJECT: Michigan's Comments on Proposed UCMR 3 for Public Water Systems 

The Public Water Supply Supervision (PWSS) Program in Michigan offers the following comments 

on 40 CFR Parts 141 and 142: National Primary Drinking Water Regulations: Revisions to the 

Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems published 

March 3, 2011. We appreciate the opportunity to provide comment on the proposed rule revisions. 

Michigan's PWSS Program recommends that the United States Environmental Protection Agency 

(USEPA) consider including cyanotoxins in UCMR 3. The Contaminant Candidate List 3 included 

three cyanotoxins for consideration: anatoxin-a, microsystin-LR, and cylindrospermopsin. 

Cyanotoxins are known to have human health effects, especially for sensitive populations. We also

understand analytical methods are available for cyanotoxins, removing a possible barrier to inclusion 

in UCMR 3.

Response: Please see response to comment code 38000 Other Contaminants. 

Commenter Name: Anonymous 

Commenter Organization:

Letter ID: 0039

Comment ID: 31737

Comment Code: 38000

Comment: Include some of the pesticides (none listed for UCMR-3) or needed data on other 

disinfection by- products. EPA currently only requires testing for 2 DBP's (trichlormethane and 

halgenated acetic acids). There are literally hundreeds of DBP's.

Response: Please see response to comment code 38000 Other Contaminants.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31907

Comment Code: 38000

Comment: Additional Comments on Microbiological Candidate Contaminants 

As discussed below, it may be appropriate to include some of the additional microbiological 

candidate contaminants from the CCL3 while others should not be included in the UCMR3. 

Hepatitis A virus (HAV). It is appropriate to not include this virus on the UCMR at this time. 

Although there are still an estimated 32,000 new infections each year in the US, vaccines against 

HAV became available in 1995 and, starting in 2006, the CDC recommended routine vaccination of 

all children (Fiore et al, 2006). This practice, as well as universal vaccination against rotavirus (Staat

et al, 2008), should result in the eventual elimination of indigenous transmission of these viruses in 

the US.
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Adenovirus. The USEPA may want to consider including adenovirus on the UCMR3 list for the 

following reasons: Borchardt’s data (2008) show low concentrations and a lack of association 

between the presence of adenoviruses and enteric disease. Also, the waterborne transmission route 

for adenovirus-based disease has not been definitively proven. However, as Borchardt (2008) and 

others (e.g., Katayama et al, 2008; Rodriguez et al, 2008) have shown, adenoviruses are among the 

most common virus groups detected in water. In order to investigate the correlation, or cooccurrence, of adenovirus and other viruses in the Borchardt (2008) and other studies, the USEPA 

may wish to also consider monitoring for adenoviruses, not as pathogens themselves, but as a 

potential "single viral indicator" of the presence of other pathogenic human enteric viruses (HEV).

However, if adenoviruses are monitored, the NanoCeram filter may not be appropriate for this 

group of viruses (Gibbons et al, 2010; as cited in the proposed UCMR3). Also, with regard to the 

Ground Water Rule (GWR)(USEPA, 2006), because adenoviruses are the most UV-resistant group 

of microbes, and because the GWR UV dose requirements are based on inactivating adenoviruses, 

the USEPA may wish to generate additional data on the presence of adenoviruses in groundwater. 

Such data could be generated in conjunction with epidemiological studies similar to those of 

Borchardt (2008) but in other locations in the US. If such studies confirmed the findings of 

Borchardt (2008), who observed a lack of association of gastrointestinal illness with adenovirus 

concentrations, then perhaps the GWR UV dose requirements could be reduced. Reduced UV dose 

requirements would result in substantial cost savings for many public water systems.

Pathogenic bacteria. Not including all bacteria from the CCL3 is appropriate at this time. 

Campylobacter jejuni, Escherichia coli (O157), Helicobacter pylori, Salmonella enterica, and Shigella 

sonnei are easily killed by all potable water disinfectants in common use and the microbial indicators 

in use today (coliform bacteria and enterococcus) are satisfactory indicators of the potential presence

of these pathogens. 

Legionella pneumophila causes more waterborne outbreaks and serious disease in the US than any 

other pathogen (Post et al., 2011), but this bacterium, and environmental Mycobacterium (including 

the M. avium complex as listed in the CCL3), are ubiquitous, naturally occurring organisms (not the 

result of fecal pollution). Importantly, these organisms are problems associated with distribution 

systems. As such, monitoring of these organisms in source waters would not be a productive use of 

financial resources.

Pathogenic protozoa. Monitoring for Naegleria fowleri through the UCMR3 or another monitoring 

program may be appropriate in some cases. Like Legionella, Naegleria fowleri is a commonlyoccurring, free-living thermophilic organism. Although the disease, primary amoebic 

meningoencephalitis, is fatal following exposure of susceptible individuals, the incidence in the US is 

extremely rare with a 14-year average of 2 cases per year (Post et al., 2011). However, because 11 of 

143 wells (8%), with an average water temperature of 29o C were found to contain Naegleria (Blair 

et al, 2008), the USEPA may wish to consider conducting a summer monitoring survey of "warm 

water" wells in the US (with a suitable control group of "cold water" wells). 

Response: EPA agrees that adenovirus appears, based on the WAHTER study and other data, to 

be the most common enteric virus found in untreated ground water, when ground water is assayed 

using qPCR analysis (for DNA viruses). Ground water samples collected during the WAHTER 

study and analyzed for adenovirus by integrated cell culture/polymerase chain reaction (ICC/PCR) 
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by Dr. Aaron Margolin, University of New Hampshire, apparently were all cytopathic effect (CPE) 

negative, suggesting that at least some of the adenoviruses were not infectious. If the adenoviruses 

found in the WAHTER study samples were largely not infectious, this could explain the absence of 

adenovirus-associated AGI health effects. In contrast, Hunt et al, (2010) assayed samples from three 

wells in three (of fourteen) communities participating in the WAHTER study by ICC/PCR. Six 

samples from two wells were adenovirus positive. Because these samples had CPE (in one, as 

compared with the standard method of two passages) it is possible that these adenoviruses were not 

infectious. EPA agrees that adenovirus assay by qPCR is highly suitable as an indicator for enteric 

virus presence/absence and considered adding qPCR adenovirus assay as either an indicator or a 

pathogen in the UCMR3 sample plan. However, based on the equivocal adenovirus assay results 

reported in the WAHTER studies, there was insufficient basis to do so. In choosing among possible 

virus indicator assays, EPA identified less expensive alternatives that the agency believes will 

effectively meet our needs.

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.
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Comment Code: 38100 Chromium-6 

Summary Response to Comments on Chromium-6: EPA has decided to include monitoring for 

both soluble chromium-6 and total chromium. This monitoring, at both EPTDS and DSMRT 

locations, will provide EPA with the nationwide occurrence data necessary to support future 

regulatory decision making. 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. 

Monitoring for both total chromium and chromium-6 may help determine a relationship between 

the two, allowing for consideration of various regulatory strategies. EPA selected sec-butylbenzene 

and n-propylbenzene, non-carcinogenic VOCs, for removal after considering data submitted by 

states that indicate very low occurrence rates. EPA also considered the fact that the currently 

available health reference levels, 10.3 μg/L and 5.83 μg/L, respectively, are well above the reported 

levels of occurrence in these data.

Chromium may be present in several valence states. The health impacts of chromium are dependent 

upon the valence state. For example, chromium-3 is considered an essential element for human 

health. EPA currently regulates chromium as total chromium. The amount measured when analyzing 

for "total chromium" is the sum of chromium in all of its valence states. The MCL for EPA's 

current total chromium regulation was determined based upon the health effects of chromium-6.

EPA recently developed and validated 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. This method relies on the same instrumentation and chemistry as 

used in Method 218.6, a widely used method for the analysis of chromium-6. The primary revisions 

address the buffers used in analyte preservation and the length of the sample holding time. Method 

218.7 provides additional flexibility and extended sample holding times as compared to Method 

218.6.

Individual Comments

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31597

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 31600 Testosterone

Comment: * In the event EPA believes the potential health effects surrounding low-level exposure 

to hexavalent chromium (Cr-VI) warrant its addition to the list, then the agency should add Cr-VI to 

UCMR-3 (See Comment 2, Hexavalent Chromium).

* If EPA adds Cr-VI to the UCMR-3 list, then it should remove testosterone and also consider 

removing the other hormones not on CCL 3 from the list for the following reasons: 
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38100 Chromium-6 Page 286 of 401

- Hormones in general were not captured in the initial screening process for CCL 3. Based on the 

research to date, the occurrence of hormones in water appears to be more a concern to aquatic life 

than human health. 

Response: EPA believes that monitoring for testosterone and 4- androstene-3,17-dione is justified. 

Published articles show the occurrence of testosterone and 4- androstene-3,17-dione in surface 

waters and 4- androstene-3,17-dione in drinking water. Testosterone and 4- androstene-3,17-dione 

have been shown to be relatively resistant to oxidation. EPA has further described its rationale for 

including these contaminants in the proposed rule on March 3, 2011 (76 FR 11713). Please see 

response to comment codes 31000 Hormones and 38100 Chromium-6.

Commenter Name: Scott Nally

Commenter Organization: Ohio Enviromental Protection Agency 

Letter ID: 0046

Comment ID: 31608

Comment Code: 38100

Comment: Hexavalent chromium (chromium-6)

U.S. EPA specifically requested comment on whether chromium-6 should be included as one of the 

30 contaminants for UCMR 3 Assessment Monitoring. Ohio EPA does not have any unique 

information regarding health effects, occurrence or methods for chromium-6. However, if U.S. EPA 

intends to pursue regulation of chromium-6 in drinking water, Ohio EPA recommends using the 

existing process for prioritizing research and data collection efforts and making regulatory 

determinations, including collection of occurrence data through UCMR 3. Substitution for proposed 

UCMR 3 contaminants

U.S. EPA also specifically requested comments on what contaminant(s) should be removed from 

the list of 30 UCMR 3 contaminants if chromium-6 or another contaminant were added to the list. 

Ohio EPA recommends that those contaminants be removed from the list that are expected to have 

the least chance of occurrence based on available data, or have the least reliable method. 

Please accept these comments. If you have any questions, please contact Beth Messer at

beth.messer@epa.state.oh.us or 614-644-2752.

Sincerely, Scott J. Nally Director, Ohio Environmental Protection Agency cc: Michael G. Baker, 

Chief, Division of Drinking and Ground Waters Ohio Environmental Protection Agency 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31616

Comment Code: 38100
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Comment: Please see attached comments from Connecticut in regard to the revisions to UCMR3

April 29, 2011 Water Docket United States Environmental Protection Agency Mail Code 2822llT

1200 Pennsylvania Avenue, NW. Washington, DC 20460 Subject: Docket 1D No. OW-2009-0090, 

UC.MR3

Comments Coordinator, 

The Connecticut Department of Public Health (CTDPH) thanks EPA for the opportunity to 

comment on the revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for 

public water systems. In response to EPA's request on whether the Agency should include 

chromium-6 as one of the 30 contaminants for UCMR3 Assessment Monitoring, CTDPH strongly 

supports the need to include Chromium-6 on the proposed UCMR3 list given the national publicity 

that it received and the apparent health risk associated with exposure to this contaminant.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31621

Comment Code: 38100

Comment: In addition, CTDPH recognizes that there are some concerns relative to the analytical 

method for Chromium-6 and offers some suggestions, as noted here in attachment #1, for EPA's 

consideration. CTDPH believes that the study of Chromium-6 is best covered under the UCMR3 

process, and is hopeful that EPA will consider this inclnsion and will revise the list to include 

Chromium-6. Once again thank you for giving us the opportunity to share onr comments. If there 

are any questions, please call Michael Hage at 860-509-7333.

Lori Mathieu Public Health Section Chief Drinking Water Section Attachment # 1 Cc: Office of 

Information and Regulatory Affairs. (01vfS), Attn: Desk Officer for EPA, 725 17th St.. NW., 

Washington, DC 20503

Attachment #1

The analytical monitoring method listed by EPA for hexavalent chromium is the Dionex 

modification to EPA Method 218.6. There are not too many labs (either public or private) that 

were/are set up to do the modified Method 218.6, and given the recent concerns about hexavalent 

chromium, the Connecticut Department of Public Health (CT DPH) encourages EPA to consider 

alternative approaches. Although ion chromatography is a common technique in many laboratories, 

Method 218.6 requires an add-on detector module which is not commonly used. That module is not 

compatible with the detector systems used routinely and would require laboratories to either 

purchase an entirely new ion chromatography system or to have an "extra" system that could be 

dedicated to this analysis.
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Response: Since the revisions to Method 218.6 made in Method 218.7 do not impact the basic 

chemistry or any of the procedures in Method 218.6, laboratories that are currently using Method 

218.6 can easily convert to using Method 218.7. Please see response to comment code 38100 

Chromium-6.

Commenter Name: David Chang 

Commenter Organization: Golden State Water Company (GSWC)

Letter ID: 0054

Comment ID: 31627

Comment Code: 38100

Comment: May 2, 2011 Water Docket United States Environmental Protection Agency Mail Code 

282211 T 1200 Pennsylvania Avenue, NW. Washington, DC 20460-0002

Attn: Docket ID No. OW-2009-0090 - Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR 3) for Public Water Systems

To Whom It May Concern: 

Golden State Water Company (GSWC) is pleased to submit the following comments on the March 

3, 2011 Federal Register notice requesting comment on the proposed revisions to the Unregulated 

Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems.

GSWC recommends that should EPA promulgate a final UCMR 3 that reflects differences in the 

proposed rule, USEP A should take the following into consideration: 

* GSWC supports the inclusion of hexavalent chromium (chromium-6) as one of the 30 

contaminants for UCMR 3 Assessment Monitoring. By conducting a nationwide monitoring, we will 

have a robust data set to make informed regulatory decision. GSWC supports this in lieu of the 

monitoring outlined in the voluntary guidance to water systems on monitoring for chromium-6. 

GSWC believes that chromium-6 monitoring should occur within the structure of US EPA's rules. 

However, GSWC is concerned about the availability oflaboratories that are certified to conduct 

hexavalent chromium analysis under modified EPA Method of 218.6. 

Response: Since the revisions to Method 218.6 made in Method 218.7 do not impact the basic 

chemistry or any of the procedures in Method 218.6, laboratories that are currently using Method 

218.6 can easily convert to using Method 218.7. Please see response to comment code 38100 

Chromium-6.

Commenter Name: Phillip W. Holderness 

Commenter Organization: California-Nevada Section, American Water Works Association (CANV AWWA)

Letter ID: 0055

Comment ID: 31633

Comment Code: 38100
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Comment: May 2, 2011 Water Docket United States Environmental Protection Agency Mail Code 

282211 T 1200 Pennsylvania Avenue, NW. Washington, DC 20460-0002

Attn: Docket ID No. OW-2009-0090 - Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR 3) for Public Water Systems

To Whom It May Concern: 

The California-Nevada Section of the American Water Works Association (CA-NV AWWA) is 

pleased to submit the following comments on the March 3, 2011 Federal Register notice requesting 

comment on the proposed revisions to the Unregulated Contaminant Monitoring Regulation 

(UCMR 3) for Public Water Systems.

CA-NV Section of AWWA recommends that should EPA promulgate a final UCMR 3 that reflects 

differences in the proposed rule, USEP A should take the following into consideration: 

* CA-NV AWWA supports the inclusion of hexavalent chromium (chromium-6) as one of the 30 

contaminants for UCMR 3 Assessment Monitoring. By conducting a nationwide monitoring, we will 

have a robust data set to make informed regulatory decision. GSWC supports this in lieu of the 

monitoring outlined in the voluntary guidance to water systems on monitoring for chromium-6. 

GSWC believes that chromium-6 monitoring should occur within the structure of US EPA's rules. 

However, GSWC is concerned about the availability oflaboratories that are certified to conduct 

hexavalent chromium analysis under modified EPA Method of 218.6.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name:

Commenter Organization: Northern Kentucky Water District

Letter ID: 0060

Comment ID: 31647

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: Although there has been ongoing public concerns about chromium-6 and the possible 

occurrence in the public water supply, it would be an appropriate recommendation to add Cr-6 to 

UCMR3 list as opposed to having Congress draft more aggressive legislation to immediately regulate 

this compound. It should be added to follow the usual procedure for a contaminant regulation. The 

data collected from UCMR3 will provide good data as to whether Cr-6 is a concern and should be 

regulated. With the increased public concern this has encouraged the commercial labs to look into 

the analysis of Cr-6. By the time the UCMR3 is in effect, there may be enough certified labs to cover 

the additional Cr-6 monitoring. The addition of Total Chromium to the UCMR3 list would not 

follow the typical procedure for the UCMR since Total Chromium is already a regulated

contaminant. It could be a strong recommendation, from EPA, to have utilities do a side-by side 

analysis of total chromium for the potential of a surrogate. If the Utilities were aware that the 

possible use of a surrogate for compliance would be less of a financial burden for cost of analysis, 
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38100 Chromium-6 Page 290 of 401

they might be willing to participate in the additional monitoring for total chromium during the 

UCMR3.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name:

Commenter Organization: Northern Kentucky Water District

Letter ID: 0060

Comment ID: 31648

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 34200 Molybdenum

Comment: We understand that the Safe Drinking Water Act mandates that there must be 30

contaminants on the UCMR. Therefore when a contaminant is added to the UCMR, an existing 

contaminant must be removed. The decision on what contaminant to remove from the list of 30 

UCMR3 contaminants is difficult. Molybdenum is considered to be an essential element in the body 

with an estimated daily requirement. There seems to be more beneficial information available for 

Molybdenum than negative health effects. With this information available, it might be the least

controversial contaminant to remove from the list. 

Response: EPA believes that monitoring for molybdenum is justified. Molybdenum has a health 

risk level of 35 μg/L, based upon an IRIS RfD of 0.005 mg/kg/day. Molybdenum was previously 

detected in 8% of the drinking waters sampled in the National Inorganics and Radionuclides Survey 

at a maximum concentration of 180 μg/L and with a median concentration of 10 μg/L. It was also 

detected at 57% of the 3,297 sites sampled in the National Water Quality Assessment Program, at a 

maximum concentration of over 4,000 μg/L and with a median concentration of 3 μg/L. (76 FR 

11713). Chromium-6 (hexavalent chromium) and total chromium have been added to the list of 

contaminants to be monitored. In addition, sec-butylbenzene and n-propylbenzene have been 

removed from the list of contaminants to be monitored. Please see response to comment code 

38100 Chromium-6.

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority

Letter ID: 0062

Comment ID: 31655

Comment Code: 38100

Comment: Inclusion of Hexavalent Chromium 

If EPA is considering the development of a hexavalent chromium (Cr-6) drinking water standard, it 

is appropriate that the agency follow the multi-step process laid out in the Safe Drinking Water Act. 

The first step is clearly a determination that Cr-6 represents a potential health risk in drinking water. 

If EPA’s assessment of the epidemiological and toxicological data does indicate a potential health 

risk, only then it is appropriate to develop a robust national database of occurrence through the 

UCMR process. If EPA makes such a determination in the near future, UCMR-3 seems to be a 
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timely vehicle to do the data collection, if the questions about appropriate laboratory methods raised 

by AWWA and others can be resolved in time. We believe that the methods issue is critical, and 

expect that it will receive careful scrutiny and full public review before a decision is made.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority

Letter ID: 0062

Comment ID: 31658

Comment Code: 38100

Comment: What should be removed to make room for Hexavalent Chromium EPA requested 

comment on what potential UCMR-3 contaminant should be removed to make room if hexavalent 

chromium were to be added. MWRA concurs with the information and logical approach suggested 

by the AWWA in their comments to determine the lowest priority contaminants on the current list. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Roger Sokol 

Commenter Organization: NY State Dept. of Health

Letter ID: 0065

Comment ID: 31675

Comment Code: 38100

Comment: Water Docket EPA Docket Center Environmental Protection Agency Room 3334 1301 

Constitution Ave., NW Washington, DC Attention: Docket ID N. OW-2009-0090

Re: Comments on the Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) 

The New York State Department of Health Bureau of Water Supply Protection (BWSP) appreciates 

the opportunity to comment on the U.S. Environmental Protection Agency's (EPA) proposed 

revisions to the Unregulated Contaminant Monitoring Rule - third cycle (UCMR3) published in the 

Federal Register on March 3, 2011. In general, the BWSP agrees that the proposed revisions will 

improve implementation of the UCMR, as well as provide additional information to assist EPA in 

making a determination of whether to regulate a contaminant in the interest of protecting public 

health. The BWSP offers the following comments on the proposed UCMR3, and specifically on the 

potential inclusion of chromium-6 in the UCMR contaminant list.

Chromium-6 

Due to the complex behavior of chromium-6 in the presence of chlorine (a common disinfectant) 

and the fact that existing conventional treatment processes are not effective in removing chromium6, collecting occurrence data on this contaminant should be a priority. Based on the Environmental 

Working Group (EWG) report on chromium- 6 and EPA’s response to the report, it clearly suggests 

that EPA is considering developing a specific drinking water standard for chromium-6. Collecting 
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38100 Chromium-6 Page 292 of 401

occurrence data on chromium-6 through the UCMR3 is timely and appropriate, in response to 

emerging scientific evidence and health concerns involving chromium-6. The BWSP strongly 

recommends adding chromium-6 to the UCMR3 list of contaminants for monitoring. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Roger Sokol 

Commenter Organization: NY State Dept. of Health

Letter ID: 0065

Comment ID: 31678

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 31000 Hormones

Comment: Recommendation for dropping a contaminant from the UCMR3 list 

Since EPA is limited to monitoring (up to) thirty (30) compounds for the UCMR and the proposed 

regulation already includes 30 contaminants (28 chemicals: hormones, VOCs, SOCs, metals, 

perfluorinated chemical and an oxyhalide anion and 2 viruses [entero and noro], one contaminant 

will need to be dropped from the list, should chromium-6 be added. The BWSP suggests dropping 

one of the hormones from the proposed UCMR3 list due to the fact that the 7 proposed hormones 

originate from similar sources, and we feel that collecting data on 6 of the hormones will still be a 

significant accomplishment towards addressing the issue of endocrine disruption, especially since 

some of the hormones have similar chemical structures. Chemicals with similar structures are 

expected to have similar fate and transport. 

Thank you for your consideration of these comments. Please contact Dr. Lloyd Wilson 

(lrw03@health.state.ny.us) or Ms. Kim Evans (kem01@health.state.ny.us) of my staff if we can 

provide additional information or clarification of these comments, if needed. 

Sincerely,

Roger C. Sokol, Ph.D. Director Bureau of Water Supply Protection 

Electronic cc: V. Pisani T. Hunt L. Wilson K. Evans 

Response: Please see response to comment codes 31000 Hormones and 38100 Chromium-6.

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31681

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: The State of New Mexico has the following comments on the Revisions to the 

Unregulated Contaminant Monitoring Regulation for Public Water Systems, UCMR3.
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Page 11718

EPA thus requests comment on whether the Agency should include chromium6 as one of the 30 

contaminants for UCMR 3 Assessment Monitoring. 

NMED Comment

New Mexico Environment Department samples community and nontransient noncommunity water 

systems for total chromium. During the 2005 to 2007 compliance period only one result, 83 ppb, 

was within 20 percent of the maximum contaminant level for chromium, 100 ppb. Based on service 

to a population of 100, the system would not be targeted for sampling under UCMR3 if it were an 

active system. The next highest result was 36 ppb. One thousand four hundred thirty eight, 1,438, 

results were considered. Only 27 percent of the results were greater than 5 ppb. Speciation of 

chromium would not benefit the state of New Mexico.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31682

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 36000 Perfluorinated Compounds (PFCs); 

38200 Total Chromium

Comment: Page 11718

EPA requests comments on what contaminants should be removed from the list of 30 UCMR 3 

contaminants if chromium6 were added, as well as comments regarding the recommended and 

alternative analytical methods and the appropriate reporting level. EPA also requests comments on 

whether total chromium should also be measured concurrent with chromium6. 

NMED Comment

If chromium6 is added, it should be measured concurrent with total chromium. If chromium6 were 

added, deletion of either perfluorononanoic acid, PFNA; perfluorohexane sulfonic acid, PFHxS; 

perfluoroheptanoic acid, PFH pA; or perfluorobutane sulfonic acid, PFBS, is recommended. The 

other two perfluorinated chemicals should be monitored in New Mexico because they are used in 

fire fighting. New Mexico is subject to fires in periods of drought and high winds. 

Response: Please see response to comment codes 38100 Chromium-6 and 36000 Perfluorinated 

Compounds (PFCs). 

Commenter Name: Olga Naidenko

Commenter Organization: Environmental Working Group 
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Letter ID: 0073

Comment ID: 31691

Comment Code: 38100

Comment: 2. Monitoring for chromium-6 in water supplies nationwide EWG has long been 

troubled by the absence of a federal drinking water standard for hexavalent chromium, which the 

EPA has suggested is a probable human carcinogen via the oral route of exposure (EPA 2010a). 

EWG undertook a study to test tap water in 35 U.S. cities for the presence of this toxic 

contaminant. The results, released in December 2010 (http://www.ewg.org/chromium6-in-tapwater), found that 31 of 35 samples contained measurable levels of hexavalent chromium. Follow up 

testing by several water utilities in the cities where EWG found highest levels of chromium-6 

confirmed EWG findings and, in some cases, found even higher levels than those detected by EWG 

(EWG 2011). These findings indicate American tap water may be widely contaminated with this 

potent, toxic substance.

Within 72 hours of EWG report’s release, EPA Administrator Lisa Jackson announced a four-point 

plan to monitor hexavalent chromium contamination in the nation’s drinking water. She pledged 

swift action in risk assessment and regulation of this contaminant (EPA 2010b). EWG strongly 

supports fast-track, enhanced monitoring for chromium-6. EPA has already issued guidance 

recommending how public water systems might enhance monitoring and sampling programs 

specifically for hexavalent chromium (EPA 2011). EWG urges EPA to continue with this plan to 

provide data about chromium-6 occurrence in tap water supplies much faster than what would be 

done under the unregulated contaminant monitoring plan. Environmental Working Group 

comments on EPA’s proposed list of tap water pollutants to be tested under Unregulated 

Contaminant Monitoring Rule 

In conclusion, EWG fully supports the systematic, committed work of the EPA that aims to protect 

the health of all Americans from adverse health effects of numerous currently unregulated tap water 

pollutants that are found in water supplies across the country (EWG 2009c). This program requires 

a judicious choice on the part of the agency on conducting longterm monitoring for some 

contaminants, while expediting testing for others, where public health needs require it. The EPA 

decision to place perfluorinated chemicals on the Unregulated Contaminant Monitoring list, and to 

conduct enhanced monitoring for chromium-6 strikes an appropriate balance, and EWG urges the 

agency to continue with this plan. 

Olga V. Naidenko, PhD Senior Scientist, Environmental Working Group 

References

Apelberg BJ, Witter FR, Herbstman JB, Calafat AM, Halden RU, Needham L, et al. 2007. Cord 

Serum Concentrations of Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoate (PFOA) in 

Relation to Weight and Size at Birth. Environ Health Perspect 115(11): 1670-6.

Environmental Working Group (EWG). 2009a. New EWG tests find the pollutant in Washington 

DC tap water. Available at: http://www.ewg.org/report/bush-administration-moves-okaytoxicteflon-pollution- tap-water
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

38100 Chromium-6 Page 295 of 401

Environmental Working Group (EWG). 2009b. Pollution in Minority Newborns. Available: 

http://www.ewg.org/minoritycordblood/home 

Environmental Working Group (EWG). 2009c. Drinking Water Quality Analysis and Tap Water 

Database. Available at: http://www.ewg.org/tap-water/executive-summary

Environmental Working Group (EWG). 2010. Chromium-6 in U.S. Tap Water. Available at: 

http://www.ewg.org/chromium6-in-tap-water

Environmental Working Group (EWG). 2011. Cities Confirm EWG Tap Water Tests. Available: 

http://www.ewg.org/release/utilities-confirm-ewg-water-tests

Fei C, McLaughlin JK, Lipworth L, Olsen J. 2009. Maternal levels of perfluorinated chemicals and 

subfecundity. Hum Reprod 24(5): 1200-05.

Kato K, Wong LY, Jia LT, Kuklenyik Z, Calafat AM. 2011. Trends in Exposure to Polyfluoroalkyl 

Chemicals in the U.S. Population: 1999-2008. Environ Sci Technol: in press. 

Joensen UN, Bossi R, Leffers H, Jensen AA, Skakkebæk NE, Jørgensen N. 2009. Do Perfluoroalkyl 

Compounds Impair Human Semen Quality? Environ Health Perspec 117(6): 923- 27.

Knox SS, Jackson T, Javins B, Frisbee SJ, Shankar A, Ducatman AM. 2011. Implications of Early 

Menopause in Women Exposed to Perfluorocarbons. J Clin Endocrinol Metab: in press. 

Lopez-Espinosa MJ, Fletcher T, Armstrong B, Genser B, Dhatariya K, Mondal D, et al. 2011. 

Association of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) with Age of 

Puberty among Children Living near a Chemical Plant. Environ Sci Technol: in press. 

U.S. Environmental Protection Agency (EPA). 2010a. IRIS Toxicological Review of Hexavalent 

Chromium (External Review Draft). Available:

http://cfpub.epa.gov/ncea/iris_drafts/recordisplay.cfm?deid=221433 

U.S. Environmental Protection Agency (EPA). 2010b. EPA Statement on Chromium-6 in Drinking 

Water. Available at:http://yosemite.epa.gov/opa/admpress.nsf/6427a6 

b7538955c585257359003f0230/9a9bda12333b 623385257800007e5c84!OpenDocument

U.S. Environmental Protection Agency (EPA). 2011. EPA Issues Guidance for Enhanced 

Monitoring of Hexavalent Chromium in Drinking Water. Available: 

http://yosemite.epa.gov/opa/admpress.nsf/6427a6b7538955c585257359003f0230/93a75b 03149d 

30b08525781500600f62!OpenDocument

Zhang T, Wu Q, Sun HW, Zhang XZ, Yun SH, Kannan K. 2010a. Perfluorinated compounds in 

whole blood samples from infants, children, and adults in China. Environ Sci Technol 44(11): 4341-

7.

Zhang T, Sun HW, Wu Q, Zhang XZ, Yun SH, Kannan K. 2010b. Perfluorochemicals in meat, eggs 

and indoor dust in China: assessment of sources and pathways of human exposure to 

perfluorochemicals. Environ Sci Technol 44(9): 3572-9.
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White SS, Stanko JP, Kato K, Calafat AM, Hines EP, Fenton SE. 2011a. Gestational and Chronic 

Low-Dose PFOA Exposures and Mammary Gland Growth and Differentiation in Three 

Generations of CD-1 Mice. Environ Health Perspec: in press. 

White SS, Fenton SE, Hines EP. 2011b. Endocrine disrupting properties of perfluorooctanoic acid. 

J Steroid Biochem Mol Biol: in press. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action

Letter ID: 0079

Comment ID: 31699

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: Comments on Unregulated Contaminant Monitoring Rule (UCMR3) Proposed 

Revisions.

May 2, 2011 Water Docket U.S. Environmental Protection Agency 1200 Pennsylvania Ave. NW

Washington DC 20460 Attn: Docket ID No. OW-2009-0090

Clean Water Action Comments on the Unregulated Contaminant Monitoring Rule (UCMR 3)

Re: Proposed Rule, Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR #) 

for Public Water Systems (Docket ID No. EPA-HW-OW-2009-0090)

We appreciate the opportunity to comment on the U.S. Environmental Protection Agency’s (EPA) 

Proposed Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 3).

Clean Water Action is a national citizens’ organization of 1.2 million members and is active in over a 

dozen states. Clean Water Action works for strong public health and environmental protections with 

an emphasis on those that impact water resources. Clean Water Action has a long history of work on 

drinking water and on Safe Drinking Water Act implementation. 

Should EPA Include Chromium-6 in Assessment Monitoring? 

In the Proposed Revisions published March 3, 2011 in the Federal Register, EPA asked for public 

comment on whether chromium-6 should be included in UCMR Assessment Monitoring and 

whether total chromium should be measured concurrently. We support this proposal given growing 

concern about hexavalent chromium in drinking water and increased evidence of public health 

threats which are greater than previsously understood. Understanding occurrence of hexavalent 

chromium offers an opportunity to reduce public health risk for those served by Public Water 

Systems.
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While we recognize that EPA has initiated a voluntary program in which many Public Water 

Systems are monitoring for this contaminant, the UCMR data can provide a more robust data set 

and assist in understanding the actual occurrence of chromium-6 nationwide in different types of 

source water and in different sizes of systems. Concurrent monitoring for total chromium makes 

sense in light of the need to understand both relative occurrence and whether total chromium is an 

appropriate surrogate. 

We also recognize that EPA’s Toxicological Review of Hexavalent Chromium will be completed this 

year and will prompt a review of the current MCL for Total Chromium. We urge EPA not to delay 

any regulatory determination indicated by the Toxicological Review.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action

Letter ID: 0079

Comment ID: 31700

Comment Code: 38100

Comment: Which Contaminants Should Be Removed? 

We recognize that the UCMR program can only include 30 contaminants and that additions to the 

list require that other contaminants be removed. We recommend that EPA devise a process to 

reevaluate priorities. Because a majority of contaminants on the proposed UCMR 3 list are on the 

most recent Contaminant Candidate List (CCL3), the process could include reviewing those 

contaminants in the proposed UCMR that are NOT on CCL 3 and weighing the value to be gained 

in terms of near-term regulatory determination should these remain on the list as compared to those 

that ARE on CCL3. The process could also include reviewing contaminants that were not on EPA’s 

February 2008 Draft CCL 3 list and yet did appear on the final October 2009 CCL3 list. Review of 

data and considerations that informed decisions about CCL3 and even the Preliminary Contaminant 

Candidate List (PCCL 3) can help EPA determine where UCMR data will most effectively support 

like regulatory determinations and thus be helpful in determining how to revise the proposed 

UCMR3 list.

Thank you for considering these comments on the Proposed Revisions to the Unregulated 

Contaminant Monitoring Rule (UCMR3). 

Lynn Thorp, National Campaigns Coordinator, Clean Water Action 202-895-0420 ext. 109; 

lthorp@cleanwater.org 1010 Vermont Ave. NW; Suite 400 Washington DC 20005

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Eddy So 

Commenter Organization: San Francisco Public Utilities Commission

Letter ID: 0082

Comment ID: 31704
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Comment Code: 38100

Other EPA Comment Codes and Descriptions: 34400 Strontium ; 38200 Total Chromium

Comment: Inclusion of Hexavalent Chromium in UCMR3 We support the inclusion of hexavalent 

chromium as one of the 30 contaminants for Assessment monitoring in the final UCMR3. We also 

believe that concurrent monitoring of total chromium could provide crucial information regarding 

the relative occurrence of these contaminants and help determine in the future whether utilities and 

regulatory agencies should continue the use of total chromium as a surrogate for hexavalent 

chromium. However, we suggest EPA describe in the final UCMR3 what approach, if chosen, 

would be used to characterize the relationship of total chromium as the hexavalent chromium 

surrogate.

If something needs to be removed from the proposed UCMR3 list to make room for hexavalent 

chromium, we suggest excluding strontium for the following reasons: 

- Based on available information from World Health Organization[FN1: World Health 

Organization: Concise International Chemical Assessment Document 77: Strontium and Strontium 

Compounds, 2010], there are data on strontium concentrations at many points in the public water 

system, including entry, various points in the treatment and distribution systems, and finished 

drinking water, and

- It is not a major additive (as compared with molybdenum and vanadium) to alloy steel, so the 

release of strontium is not expected to be more significant than the others. Thus, the inclusion of 

strontium in this round of UCMR3 is less justified than hexavalent chromium and the other three 

inorganic contaminants. 

Regards,

- Eddy So, P.E.(Civil), P.E.(Mech) Regulatory Workgroup Supervisor Water Quality Division San 

Francisco Public Utilities Commission 1657 Rollins Road Burlingame, CA 94010 Tel: 650-652-3115

Email: eso@sfwater.org

Response: EPA believes that monitoring for strontium is justified. While strontium has a relatively 

high health risk level of 4,200 μg/L, it has previously been detected at high percentages (>90%) in a 

number of water occurrence studies, with upper levels of quantitation at concentrations far 

exceeding this health level. Chromium-6 (hexavalent chromium) and total chromium have been 

added to the list of contaminants to be monitored. In addition, sec-butylbenzene and 

n-propylbenzene have been removed from the list of contaminants to be monitored. Please see 

response to comment code 38100 Chromium-6.

Commenter Name: Deborah H. Metz 

Commenter Organization: Greater Cincinnati Water Works (GCWW)

Letter ID: 0085

Comment ID: 31709

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 34000 Metals
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Comment: 4. Which metal could be dropped if hexavelent chromium monitoring is added 

a. We recommend dropping a metal with least known amount of human health effects data

Response: EPA believes that monitoring for the selected metals are justified. Cobalt is a 2b possible 

human carcinogen, molybdenum has a health risk level of 35 μg/L and vanadium has a health risk 

level of 21 μg/L. While strontium has a relatively high health risk level of 4,200 μg/L, it has 

previously been detected at high percentages (>90%) in a number of water occurrence studies, with 

upper levels of quantitation at concentrations far exceeding this health level (76 FR 11713). 

Chromium-6 (hexavalent chromium) and total chromium have been added to the list of 

contaminants to be monitored. In addition, sec-butylbenzene and n-propylbenzene have been 

removed from the list of contaminants to be monitored. Please see response to comment code 

38100 Chromium-6.

Commenter Name: Liane J. Shekter Smith

Commenter Organization: State of Michigan Department of Environmental Quality (DEQ)

Letter ID: 0086

Comment ID: 31712

Comment Code: 38100

Comment: Michigan has experienced some cyanotoxin impacts from recreational exposure as well 

as reports of pet illnesses including fatalities. We are also aware of human illnesses that have 

occurred in neighboring states where the source of drinking water has been the Great Lakes. 

Because we share this source with our neighbors and they are used as a source for public water 

systems in Michigan, we are concerned about the potential increase in such incidents, perhaps due to 

warmer lake temperatures resulting from climate change impacts. In order to better assess the risk 

posed by cyanotoxin exposure from drinking water, we recommend that the USEPA include it in 

UCMR 3.

The USEPA also specifically requested comment on whether chromium-6 should be included as one 

of the 30 contaminants for UCMR 3 Assessment Monitoring. Michigan's PWSS Program strongly 

urges USEPA to follow the existing framework for developing new drinking water standards which 

includes conducting occurrence monitoring under the UCMR 3. Therefore, we recommend 

chromium-6 be included in UCMR 3 if the USEPA intends to pursue regulation of chromium-6 

ahead of other contaminants currently on this list. 

If the USEPA needs to remove contaminants from the current UCMR 3 list to make room for 

cyanotoxins and chromium-6, we recommend those contaminants expected to have the least chance 

of occurrence or least reliable analytical methods be removed. 

Thank you for the opportunity to provide these comments. If you have any questions, please 

contact Mr. Richard Benzie, Resource Management Division, at 517-241-1245, 

benzier@michigan.gov, or at Michigan Department of Environmental Quality (MDEQ), P.O. Box 

30241, Lansing, Michigan 48909-7741.
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Sincerely,

Liane J. Shekter Smith, P.E., Chief Resource Management Division 517 -373-9523

cc: Mr. Richard Benzie, MDEQ

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31721

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: 4. Chromium and Hexavalent Chromium Monitoring. EPA requests comments on 

whether to include hexavalent chromium (Cr-6) and/or total chromium (Cr) on the list of 30 

contaminants proposed for UCMR3 for Assessment Monitoring. CVWD recommends both Cr-6 

and Cr be included in UCMR3 for assessment monitoring (List 1). While UCMR monitoring should 

be used for unregulated contaminants, CVWD believes that the unique transitional relationship 

between source water Cr levels and Cr-6 levels found in PWS’s that practice disinfection justifies the 

inclusion of the regulated contaminant Cr in UCMR3. Cr monitoring may also represent a cost 

effective, practicable and improved surrogate for monitoring Cr-6 occurrence in PWSs. Water 

agencies in California have already completed comprehensive Cr-6 source water monitoring in 

accordance with California unregulated contaminant monitoring requirements and in many cases 

virtually all of the naturally occurring Cr found in the source water was found in the oxidized form 

as Cr-6. Water agencies with this knowledge can benefit from using the more cost effective and 

practicable Cr test method for future determinations regarding Cr-6 occurrence in drinking water 

sources.

Including Cr and Cr-6 in the UCMR3 is also consistent with recent EPA efforts to improve 

occurrence data for Cr-6. Unlike EPA’s recent recommendation for voluntary enhanced Cr-6 

monitoring, UCMR3 is the right tool for implementing this type of occurrence monitoring. UCMR3 

provides a program that includes a peer reviewed validation process for sample collection and 

analytical methods and provides a centralized database that allows this occurrence data to be used

effectively for regulatory decisions. Including Cr and Cr-6 in UCMR3 allows water agencies to 

combine Cr and Cr-6 monitoring with other chemical monitoring included in UCMR3, which is 

more cost effective and efficient than any "enhanced" single contaminant monitoring campaign. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31722

Comment Code: 38100
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Other EPA Comment Codes and Descriptions: 37000 Viruses; 38200 Total Chromium

Comment: 5. Removing Virus Monitoring. CVWD believes including Cr and Cr-6 monitoring on 

the list of 30 contaminants is more timely and beneficial than the proposed monitoring for two 

viruses (Norovirus and Enterovirus). Test methods for these viruses have not been validated and the 

work by Borchardt used to support virus monitoring has not been peer reviewed. CVWD also 

believes the proposed virus monitoring performed at 800 PWS’s serving less than 1,000 persons 

using undisinfected sources producing groundwater from karst or fractured bedrock formations will 

provide occurrence data of limited value that is not representative of most drinking water served in 

the U.S. Removing monitoring for the two viruses will allow the addition of Cr and Cr- 6 

monitoring without exceeding the prescribed limit of 30 contaminants for UCMR monitoring and 

provide more valuable information for future regulatory decisions. 

Response: Most virus-indicator correlation studies have been performed in disinfected systems. 

UCMR 3 monitoring will specifically focus on undisinfected ground water systems. 

Theoretically, this study could be conducted outside the UCMR 3 program, though EPA believes 

that this effort is far bigger and more complex in scope and funding than a research project can 

achieve. Thus EPA believes that the UCMR 3 is the best mechanism. UCMR 3 will provide 

occurrence data; the main idea is that if occurrence (in sensitive and undisinfected systems) is similar 

on a national scale to that found by Borchardt, exposure and health risks are likely to be similar. 

EPA disagrees that the rationale for conducting virus monitoring under UCMR 3 is weak and 

believes that a national study is warranted based upon the Borchardt data. The virus method EPA is 

using includes all the elements the commenter has suggested except for the multi-laboratory 

validation. However, EPA will be conducting a PT program prior to the monitoring. This will serve 

both as a "multi-laboratory validation" of the method as well as an evaluation of the performance of 

laboratories. Commercial laboratories will be selected based on their performance in a PT study.

Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Anonymous 

Commenter Organization:

Letter ID: 0039

Comment ID: 31739

Comment Code: 38100

Comment: With all the hoopla about hexavalent chromium, wouldn't it be a good idea to utilze 

UCMR-3 to find the actual occurance rather than rely on EWG's results. Come on EPA-be more 

pro- active and avoid the embarressment EWG and other groups are causing you.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047
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Comment ID: 31751

Comment Code: 38100

Comment: 13. With respect to inclusion of Cr6+ in the UCMR3 monitoring we are not convinced 

that it would bring much additional value to the UCMR3 program, because data available in the 

literature and from ongoing studies demonstrates that the occurrence of Cr6+ is widespread at low 

levels (ie. < 1 ug/L). Thus occurrence will not be the driving force in regulatory determinations. We 

also feel that including Cr6+ in the UCMR3 would create a reliable consistent national database (as 

opposed to the data generated in an ad-hoc manner by EWG) and the additional cost of including 

this analyte is minimal compared to other UCMR3 monitoring costs. The actual cost will clearly 

depend on EPA’s recommended MRL and the holding time. The more important issue for 

regulatory determination is the effectiveness of treatment and the cost of said treatment. These 

factors will not be obtained through the UCMR process. 

14. In the event that Cr6+ is included in UCMR3, it is critical that the analytical method be revised 

to clarify issues regarding field filtration, preservation, and holding time. We know EPA is working 

on all of these action items with the intent to have a completed, revised method before the end of 

the summer. We applaud EPA’s decision to thoroughly re-evaluate this method.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31753

Comment Code: 38100

Comment: 16. If Cr6+ was included, we would recommend dropping strontium because of the 

likelihood of frequent occurrences at concentrations high enough to require dilution (but still well 

below the HRL) due to the high HRL. Additionally, eliminating strontium would save utilities some 

costs, whereas eliminating individual analytes from one of the other methods would not result in any 

saving because it would not eliminate a method. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31763

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: 4. Chromium and Hexavalent Chromium Monitoring. EPA requests comments on 

whether to include hexavalent chromium (Cr-6) and/or total chromium (Cr) on the list of 30 

contaminants proposed for UCMR3 for Assessment Monitoring. WESTCAS recommends both Cr6 and Cr be included in UCMR3 for assessment monitoring (List 1). While UCMR monitoring 
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should be used for unregulated contaminants, WESTCAS believes that the unique transitional 

relationship between source water Cr levels and Cr-6 levels found in PWS’s that practice disinfection 

justifies the inclusion of the regulated contaminant Cr in UCMR3. Cr monitoring may also represent 

a cost effective, practicable and improved surrogate for monitoring Cr-6 occurrence in PWSs. Water 

agencies in California have already completed comprehensive Cr-6 source water monitoring in 

accordance with California unregulated contaminant monitoring requirements and in many cases 

virtually all of the naturally occurring Cr found in the source water was found in the oxidized form 

as Cr-6. Water agencies with this knowledge can benefit from using the more cost effective and 

practicable Cr test method for future determinations regarding Cr-6 occurrence in drinking water 

sources.

Including Cr and Cr-6 in the UCMR3 is also consistent with recent EPA efforts to improve 

occurrence data for Cr-6. Unlike EPA’s recent recommendation for voluntary enhanced Cr-6 

monitoring, UCMR3 is the right tool for implementing this type of occurrence monitoring. UCMR3 

provides a program that includes a peer reviewed validation process for sample collection and 

analytical methods and provides a centralized database that allows this occurrence data to be used

effectively for regulatory decisions. Including Cr and Cr-6 in UCMR3 allows water agencies to 

combine Cr and Cr-6 monitoring with other chemical monitoring included in UCMR3, which is 

more cost effective and efficient than any "enhanced" single contaminant monitoring campaign. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Diane VanDe Hei 

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31767

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 31600 Testosterone

Comment: 2. Hexavalent Chromium 

Should EPA include Cr-VI and if Cr-VI is added, what should be removed from list?

AMWA recommends that EPA include Cr-VI in UCMR-3 if the agency can clearly state that Cr-VI 

poses a significant public health risk at the low levels likely to be found in finished drinking water. 

Including Cr-VI in UCMR-3 will result in a reliable, nationally consistent dataset not currently 

available. The Cr-VI data obtained from the UCMR monitoring will be appropriate for informing 

the decision about whether to regulate Cr-VI on its own, rather than as total chromium. As Cr-VI is 

not currently regulated with its own MCL under the SDWA, AMWA believes that it is appropriate 

and allowable for inclusion in the UCMR. 

If Cr-VI is added to the list, AMWA recommends that EPA remove testosterone and also consider 

removing the other hormones from UCMR because: 

- hormones in general were not captured in the screening process for CCL 3. Based on the research 

to date, the occurrence of hormones in water appears to be more a concern to aquatic life than 

human health; 
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- there is a likelihood at the proposed reporting levels to find testosterone and some of the other 

hormones occurring at very low levels; and

- due to the low levels of occurrence likely to be found and lack of field blanks identified in the 

analytical method, there may well be false positive measurements.

Response: EPA believes that monitoring for testosterone is justified. EPA has described its 

rationale for including this contaminant in the proposed rule on March 3, 2011 (76 FR 11713). A 

number of published articles show the occurrence of testosterone in surface waters and testosterone 

has been shown to be relatively resistant to oxidation. Sec-butylbenzene and n-propylbenzene have 

been removed from the list of contaminants to be monitored. Chromium-6 (hexavalent chromium) 

and total chromium have been added to the list of contaminants to be monitored. 

Please see response to comment codes 31000 Hormones and 38100 Chromium-6.

Commenter Name: Randy Gottler

Commenter Organization: City of Phoenix Water Services Department (WSD)

Letter ID: 0091

Comment ID: 31785

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: UCMR Contaminant List - Chromium and Hexavalent Chromium EPA requests 

comments on whether to include hexavalent chromium and/or total chromium on the list of 

contaminants proposed for UCMR 3 for Assessment Monitoring. The WSD supports including 

hexavalent chromium measured concurrent with total chromium to determine the suitability of total 

chromium monitoring as a cost effective and practicable surrogate for monitoring hexavalent 

chromium in public water systems. Unlike voluntary monitoring programs, assessment monitoring 

for UCMR 3 provides peer reviewed validation process for COP WSD Comments on UCMR3 

sample collection and analytical methods plus a centralized database that allows the effective use of 

occurrence data for regulatory decisions regarding hexavalent chromium. In addition, monitoring for 

hexavalent chromium and total chromium with other chemical monitoring included in UCMR 3 is 

more cost effective and efficient than a voluntary monitoring campaign for only hexavalent 

chromium. 

We appreciate the opportunity to provide these comments. Please feel free to contact me at 602-

534-1358 if you have any questions or wish to discuss our comments.

Sincerely,

Randy Gottler Compliance and Regulatory Affairs Administrator 

c: John Calkins, Arizona Department of Environmental Quality Korissa Entringer, Maricopa 

County Environmental Services Department Carlos Padilla Troy Hayes Stephen Wetherell 

Response: Please see response to comment code 38100 Chromium-6.
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Commenter Name: Thomas LaHue 

Commenter Organization: Soquel Creek Water District (SqCWD),

Letter ID: 0094

Comment ID: 31786

Comment Code: 38100

Comment: April 20, 2011 Water Docket United States Environmental Protection Agency Mail 

Code 282211 T 1200 Pennsylvania Avenue, NW Washington, DC 20460 Attention Docket ID No. 

OW-2009-0090 Subject: Docket ID No. OW-2009-0090

 To Whom It May Concern:

This letter is in response to the US EPA's request for comment on whether hexavalent chromium 

(Cr-6) should be included as one of the 30 compounds for the third round of the Unregulated 

Contaminant Rule Monitoring (UCMR 3). EPA also requested comment on whether total 

chromium should be measured concurrent with Cr-6.

The Soquel Creek Water District (SqCWD) is a public agency that provides potable water service 

and groundwater resource management within Santa Cruz County, California. The SqCWD serves a 

population of about 45,000 through almost 14,000 service connections in four service subareas . 

Groundwater currently comprises 100 percent of SqCWD's water supply and is pumped from local, 

coastal aquifers. These aquifers are located within two geologic formations that underlie the SqCWD 

service area. Approximately one-third of SqCWD's water supply is from the Aromas Red Sands 

(Aromas) aquifer, which provides water for the communities of Aptos, Rio Del Mar, Seascape and 

La Selva Beach. This aquifer is also a primary drinking water supply for Central Water District, the 

City of Watsonville and numerous mutual water companies .

In 2001, the SqCWD completed testing for Cr-6 as directed by the State of California as part of the 

State's monitoring requirements for unregulated chemicals. Six of SqCWD's production wells 

completed in the Aromas aquifer had detected amounts of naturally occurring Cr-6. Cr-6 was 

detected at levels ranging from 6 to 18 parts per billion (ppb) in four wells serving portions of 

Aptos, Rio Del Mar and Seascape. In two wells serving La Selva Beach, the Cr-6 levels were 31 to 38 

ppb . 

Since Cr-6 was first detected in SqCWD wells in spring 2001, we have maintained a public outreach 

effort to keep our customers informed about this issue. We publicly announced the test results and 

disseminated press packets within days of the initial discovery and also sent individual letters to all 

affected customers providing information. In June 2001, SqCWD assembled a panel of Cr-6 experts, 

including the chief toxicologists from EPA Region 9 and the California Office of Environmental 

Health Hazard Assessment (OEHHA) and a senior official from the California Department of 

Public Health, for a well-attended public forum. We have continued to post all current 

developments with respect to the establishment of a drinking water standard on the District's web 

site as well as communicate new information through our newsletter and the media. 

The Safe Drinking Water Act (SDWA) provides EPA with a clear process for determining whether 

regulating a compound in drinking water is in the interest of protecting public health. This process is 
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the UCMR program in coordination with the Contaminant Candidate List (CCL). The UCMR/CCL 

process provides scientifically valid data on the occurrence of certain compounds in drinking water, 

enabling the EPA to assess the extent of population exposure and the levels of exposure and 

determine whether to regulate those compounds. EPA is required by the SDWA to use "best 

available, peer-reviewed science."

It is obvious the EPA is now concerned about the potential health effects of Cr-6 in drinking water, 

as evidenced by its taking the unusual step this past January of issuing guidance for voluntary 

monitoring of Cr-6. However, the logical action would have been to include Cr-6 as one of the 30 

contaminants proposed last month for monitoring under the upcoming UCMR 3. UCMR would 

provide EPA with meaningful, nationwide Cr-6 data. It is unclear if or how EPA will even acquire 

Cr-6 data from the voluntary monitoring program. Further, the data gathered under the voluntary 

program may be questionable due to the lack of a fully validated analytical method and validated 

laboratory performance standards. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas LaHue 

Commenter Organization: Soquel Creek Water District (SqCWD),

Letter ID: 0094

Comment ID: 31788

Comment Code: 38100

Comment: The SqCWD is anxious to have a Cr-6 drinking water standard established so we can 

proceed with the appropriate steps to assure affected customers that we have addressed any 

continued exposure to harmful levels of this compound in their drinking water. We are, however, 

also very concerned that circumventing the established process of promulgating primary drinking 

water standards could lead to a regulatory decision that is not based upon sound science. The 

SqCWD strongly supports validated nationwide Cr-6 occurrence studies and urges the EPA to 

include Cr-6 in UCMR 3.

If Cr-6 is not included in this UCMR 3 process, then we urge the EPA to use a similar approach 

using the best available peer reviewed science.

Thank you for considering our input on this matter. 

Sincerely, SOQUEL CREEK WATER DISTRICT Dr. Thomas LaHue, President Board of 

Directors

cc: Office of Information and Regulatory Affairs, Office of Management and Budget Attention: 

Desk Officer for EPA, 725 17th St., NW Washington, DC 20503 Steve Via, Government Affairs 

Office, American Water Works Association

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: David Lipsky
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Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31792

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38110 EPA Method 218.7 - Chromium-6 

Comment: B. Inclusion of hexavalent chromium in the proposed list (FR-p. 11718)

DEP recommends that EPA include hexavalent chromium (Cr+VI) as one of the 30 monitored 

analytes in UCMR-3 if the agency's assessment of associated health risk supports its inclusion. By 

doing so, a robust, nationally representative data set will be developed sufficient to make an 

informed regulatory determination. However, several questions need to be addressed in the final rule 

(and hopefully subject to at least additional public comment) regarding the appropriate method and 

the required MRL. Since these questions cannot be answered now, DEP recommends that perhaps 

EPA consider moving Cr+VI to Tier 2- for a screening level assessment.

EPA has yet to make a final determination on whether Cr+ VI is a potential human carcinogen 

through the oral route of exposure, and if so, the appropriate cancer slope factor to use to estimate 

the potential carcinogenic risk for lifetime exposure through drinking water. This information is still 

in draft stage and has not been reviewed by the Science Advisory Board. The information is needed 

to help determine the need for, and priority to be given to, testing for Cr+ VI in the ng/L range 

suggested by EPA guidance, and in addition, the appropriate methods and MRL to use. 

Of note, DEP analyzed samples for Cr+VI using a contract laboratory in California and following 

EPA's January 2011 guidance and found no Cr+VI at an MRL of 0.05 ug/L. However, based on our 

experience, it is DEP's understanding that additional work is required on the part of EPA to 

standardize the method and definitively answer outstanding questions about the method, including 

sample holding time and MRLs. Laboratory capacity may also be an issue. Overall, DEP believes 

that Cr+VI should be included in UCMR-3, but perhaps in Tier 2 rather than Tier 1. 

Response: Please see response to comment code 38100 Chromium-6.

Since this method relies on the same instrumentation and chemistry as Method 218.6, a method that 

has been extensively used throughout the commercial laboratory community, and since EPA has 

extended the sample holding time, EPA feels that laboratory capacity will not be an issue. Therefore, 

the monitoring of chromium-6 is best accomplished as a List 1 analyte.

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31794

Comment Code: 38100

Comment: Overall, if EPA elects to include Cr-VI on the UCMR-3 list, the agency must ensure that 

the method selected is sufficiently robust, that the MRL is appropriate, that QA/QC measures are 

defined and tested, and that the laboratory capacity is adequate. If these issues are not resolved by 
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the time the final requirements for UCMR-3 are published, then EPA should consider including CrVI only as a List 2 constituent. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31812

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: The MDH supports the inclusion of both chromium-6 and total chromium as two of

the 28 new UCMR 3 chemical contaminants designated for Assessment Monitoring under List 1. 

National occurrence data is necessary for any future regulation of chromium-6. We continue to 

support the use of the Contaminant Candidate List (CCL) process as the preferred system for the 

Administrators’ determinations regarding regulation of contaminants in the interest of protecting 

public health, as required under the SDWA section 1412 (b)(1). 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31814

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: In order to provide for chromium-6 and total chromium analysis, we recommend EPA

remove two contaminants using the same criteria used for inclusion: public health concern, 

occurrence data availability, and analysis method reliability. Furthermore, we recommend EPA 

remove at least one additional similarly-ranked contaminant in order to provide inclusion of at least 

one cyanotoxin. There is an emerging need for collection of occurrence data for cyanotoxins within 

PWSs, as documented within CCL 3 by EPA’s determination of "no comprehensive drinking water 

occurrence data" for three compounds: Anatoxin-a, Cylindrospermopsin, and Microcystin-LR. The 

collection of occurrence data, in combination with EPA’s ongoing quantitative assessments, e.g., 

Integrated Risk Information System (IRIS), will likely aid in PWS cyanotoxin risk determinations. 

Alternatively, these chemicals should be evaluated for inclusion in a potential grouped contaminant 

regulatory decision. 

Response: 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 highperformance 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. In addition, even though high-performance liquid chromatography/tandem mass 
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spectrometry (HPLC/MS/MS) methods for cyanobacterial toxins have been published (Oehrle et 

al., 2010), these methods also do not provide suitable accuracy and precision. EPA has conducted 

and will continue to conduct methods development research for cyanobacterial toxins and other 

emerging contaminants both in-house, and in cooperation with other laboratories. 

Please see response to comment code 38100 Chromium-6.

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.

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.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31822

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: Hexavalent chromium 

The EPA did not include hexavalent chromium in the proposed UCMR 3 and specifically requested 

comment regarding the possible inclusion of hexavalent chromium in the final UCMR 3 sampling. 

The TCEQ comments that the EPA should strongly consider investigatory sampling for hexavalent 

chromium, if and only if an inexpensive consensus method can be approved before the UCMR 3 

sampling cycle. No analyte should be placed at the top of the CCL prioritization for any reason 

other than sound science. If the EPA believes that it is necessary to perform pre-regulatory sampling 

for hexavalent chromium, the EPA should do a separate rulemaking, or include hexavelent 

chromium in CCL 4. If, however, the EPA includes hexavalent chromium in UCMR 3, then total 

chromium should be monitored simultaneously. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31837

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: Chromium-6 and Total Chromium 
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January 2012

38100 Chromium-6 Page 310 of 401

EPA is requesting comments on whether to include hexavalent chromium (chromium-6) as one of 

the 30 contaminants for UCMR3 for Assessment Monitoring (FR page11718). EPA is also 

requesting comments on whether to include testing for total chromium concurrently with 

chromium-6. Collecting occurrence data for both chromium-6 and total chromium would provide 

information to assess if total chromium could be a viable surrogate for chromium-6.

Although Riverside does not support the inclusion of regulated contaminants (total chromium) in 

the UCMR program, we understand the importance of collecting concurrent total chromium and 

chromium-6 data and do not disagree with including total chromium in the UCMR program. 

Therefore, Riverside recommends that EPA include both chromium-6 and total chromium in the 

UCMR3 nationwide Assessment Monitoring (List 1). 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31851

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: 7.0 Chromium-6 and Total Chromium 

EPA is requesting comments on whether to include hexavalent chromium (chromium-6) as one of 

the 30 contaminants proposed for UCMR3 for Assessment Monitoring (FR page11718). EPA is also 

requesting comments on whether to include testing for total chromium concurrently with 

chromium-6. Collecting occurrence data for both chromium-6 and total chromium would provide 

information to assess if total chromium could be a viable surrogate for chromium-6. EPA is also 

requesting comment on the analytical method and appropriate reporting level. 

7.1 Chromium-6 and Total Chromium: Inclusion in UCMR3 

The primary purpose of the Contaminant Candidate List (CCL) and the UCMR program is to 

provide information for EPA to determine which drinking water contaminants have the highest 

potential to provide a meaningful opportunity to reduce health risk by establishing a primary 

drinking water regulation. The CCL process identifies contaminants that are anticipated to occur in 

drinking water, while the UCMR program provides national occurrence information for EPA to 

determine if a contaminant occurs at a frequency and concentration that would be a public health 

concern warranting regulation. Currently, total chromium is an inorganic contaminant that is 

regulated with a primary drinking water standard which includes both chromium-6 and chromium-3. 

There is no primary drinking water standard for chromium-6.

The purpose of the UCMR program is to gather occurrence information for unregulated 

contaminants and in general OCWD would not support the inclusion of regulated contaminants in 

the UCMR cycle. However, OCWD would support inclusion of total chromium and chromium-6 as 

a one time exception in order to expedite the collection of source and occurrence information of 

chromium-6 data. With this preface, OCWD recommends that EPA include both chromium-6 and 
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January 2012

38100 Chromium-6 Page 311 of 401

total chromium in the UCMR3 nationwide Assessment Monitoring (the basis of this support is 

described below and summarized in the following table). EPA has a robust, quality-driven procedure 

(approved methods with results that are supported by meeting stringent data quality objectives - for 

nationwide laboratory consistency in reported results) in place by the UCMR program to gather 

nationwide occurrence information for contaminants of potential concern.

Chromium-6 has received national media attention and enhanced public awareness of the potential 

health risks from chromium-6 exposure, including EPA as demonstrated by their January 2011 

"Guidance for Public Water Systems on Enhanced Monitoring for Chromium-6 (Hexavalent 

Chromium) in Drinking Water." OCWD supports monitoring for chromium-6 and total chromium 

at the EPTDS and DSMRT locations to provide EPA with occurrence data to evaluate if 

chromium-3 is oxidized to chromium-6 in the presence of an oxidant (e.g., chlorine, ozone, etc.) and 

to assess the feasibility of using total chromium as a monitoring surrogate for chromium-6 (less 

costly analysis and avoids the short holding time required for chromium-6 analysis).

Chromium-6 has been a contaminant of interest in CA for over a decade. In 1999, the CA 

Department of Public Health (DPH, formerly CA Department of Health Services (CDHS)) 

indentified chromium-6 to be included in the CA’s unregulated chemicals requiring monitoring 

(UCMR). CA required analysis for chromium-6 using EPA Method 218.6 at a detection limit for 

reporting purposes (DLR) of 1 ug/L. Monitoring for chromium-6 occurred between January 1, 2001 

and December 31, 2002. CA will be developing a drinking water standard (i.e., MCL) for chromium6 once the CA Office of Environmental Health Hazard and Assessment (OEHHA) finalizes the CA 

Public Health Goal (PHG). Listed on the following table is a summary of the CA’s chromium-6 

timeline to develop a MCL in drinking water and recent national interest in chromium-6, further 

supporting the recommendation to include chromium-6 and total chromium in the final listing of 

UCMR3 chemicals.

[Table: see PDF docket ID EPA-HQ-OW-2009-0090-0052]

Including chromium-6 and total chromium in the list of 30 chemicals for UCMR3 Assessment 

Monitoring is well justified as shown by the chromium-6 timeline of events illustrating the (1) 

potential carcinogenicity of chromium-6 when ingested and (2) nationwide media coverage 

prompting public concerns and raised awareness of the potential harmful health impacts. In the 

interim of release of the final National Toxicity Program (NTP) report, including chromium-6 and 

total chromium in the UMCR3 program will provide timely occurrence information that will be 

needed in the MCL setting process. Monitoring during the 2013-2015 period will avoid delays to 

secure nationwide occurrence data if a regulatory determination to establish an MCL for chromium6 is needed based on the final NTP report on the human health assessment and exposure to 

chromium-6.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31854

Comment Code: 38100
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January 2012

38100 Chromium-6 Page 312 of 401

Other EPA Comment Codes and Descriptions: 37000 Viruses; 38200 Total Chromium

Comment: * Information gained from the limited, narrow virus focus by monitoring select 800 

small systems using undisinfected groundwater will not provide meaningful data to benefit and 

support the overall UCMR goals to provide information for future regulatory decision-making in 

contrast to the benefits potentially gained by including chromium-6 and total chromium in UCMR3. 

The value gained by testing for chromium-6 and total chromium provides national occurrence 

information that will be meaningful for EPA to determine if regulation may be warranted and far

outweighs the data gathering information for Pre-Screening testing for viruses. 

OCWD appreciates the opportunity to review and comment on the proposed UCMR3 program.

Sincerely,

Yira Namachika Director of Water Quality (714) 378-3281

Response: Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31871

Comment Code: 38100

Comment: Page 11718: "EPA thus requests comment on whether the Agency should include 

chromium-6 as one of the 30 contaminants for UCMR 3 Assessment Monitoring." 

Administrator Jackson has committed to addressing the evolving science regarding hexavalent 

chromium and there appears to be a good prospect that it will be regulated. One part of this effort 

should be to develop more robust occurrence information. EPA recently issued voluntary guidance 

to water systems on monitoring for hexavalent chromium and this should produce some useful data 

on hexavalent chromium and the relationship between hexavalent chromium and total chromium. 

However, unless EPA determines, over the next few months, that the data from this voluntary effort 

is adequate to meet its needs for occurrence data, we would recommend adding hexavalent 

chromium to the list of contaminants under UCMR3. Some states have not identified significant 

occurrence of chromium based on the compliance monitoring for total chromium at level of 

detection for current analytical methods. Monitoring using analytical methods providing lower 

detection levels and specifically targeting hexavalent chromium may not reveal any additional 

chromium issues but the additional monitoring is needed to prove that case and thus, should be 

included in the UCMR. Hexavalent chromium will continue to be a popular target until adequate 

data is available to support or refute the need for regulation. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA
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38100 Chromium-6 Page 313 of 401

Letter ID: 0066

Comment ID: 31873

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: If hexavalent chromium and total chromium, or any of the other recommended 

contaminants were added to UCMR 3, some contaminants would have to be deleted. We are not 

recommending the deletion of specific contaminants on a one to one basis but instead recommend a 

list of lower priority contaminants for EPA to consider eliminating. It’s not that that data on these 

contaminants would not be useful, but we believe they are of less value than others on the list. This

is either because states feel the contaminants will not be found at significant levels or data on their 

occurrence will not add to information gained through monitoring related contaminants that remain 

on the list. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31887

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: The NJDEP also supports including hexavalent chromium on the UCMR3 list of

contaminants for nationwide monitoring, as this contaminant has been detected in various media in 

New Jersey and in water supplies throughout the country. This monitoring should also include total 

chromium in order to further understand the relationship between the occurrence of total chromium 

and hexavalent chromium. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31894

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: 7.0 Chromium-6 and Total Chromium 

EPA is requesting comments on whether to include hexavalent chromium (chromium-6) as one of 

the 30 contaminants proposed for UCMR3 for Assessment Monitoring (FR page11718). EPA is also 

requesting comments on whether to include testing for total chromium concurrently with 

chromium-6. Collecting occurrence data for both chromium-6 and total chromium would provide 

information to assess if total chromium could be a viable surrogate for chromium-6. EPA is also

requesting comment on the analytical method and appropriate reporting level. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

38100 Chromium-6 Page 314 of 401

7.1 Chromium-6 and Total Chromium: Inclusion in UCMR3 

Chromium-6 has been a contaminant of interest in CA for over a decade. In 1999, the CA 

Department of Public Health (CDPH, formerly CA Department of Health Services (CDHS)) 

indentified chromium-6 to be included in the CA’s unregulated chemicals requiring monitoring 

(UCMR). CA required analysis for chromium-6 using EPA Method 218.6 at a detection limit for 

reporting purposes (DLR) of 1 ug/L. Monitoring for chromium-6 occurred between January 1, 2001 

and December 31, 2002. CA will be developing a drinking water standard (i.e., MCL) for chromium6 once the CA Office of Environmental Health Hazard and Assessment (OEHHA) finalizes the CA 

Public Health Goal (PHG). 

The primary purpose of the USEPA Contaminant Candidate List (CCL) and the UCMR program is 

to provide information for EPA to determine which drinking water contaminants have the highest 

potential to provide a meaningful opportunity to reduce health risk by establishing a primary 

drinking water regulation. The CCL process identifies contaminants that are anticipated to occur in 

drinking water while the UCMR program provides national occurrence information for EPA to 

determine if a contaminant occurs at a frequency and concentration that would be a public health 

concern. Currently, total chromium is an inorganic contaminant that is regulated with a primary 

drinking water standard and includes both chromium-6 and chromium-3. There is no primary 

drinking water standard for chromium-6 at the federal level or in California at this time.

Including regulated contaminants in the UCMR list is not the intended purpose of the program and 

in general ACWA would not support the inclusion of regulated contaminants in the UCMR 

program. However, ACWA is aware of the enhanced public awareness surrounding chromium-6 

exposure at lower levels than what is currently regulated and does not disagree that additional steps 

should be taken to determine if it is a risk to the public. In fact, we wrote a letter in response to 

EPA’s January 2011 "Guidance for Public Water Systems on Enhanced Monitoring for Chromium-6 

(Hexavalent Chromium) in Drinking Water," outlining California’s efforts to address chromium-6, 

the importance of appropriate and thorough occurrence data to the establishment of a drinking 

water standard, and the relationship between total chromium and chromium-6 monitoring. As a 

result, ACWA would be willing to support the inclusion of total chromium and chromium-6 as a

one-time exception in order to expedite the collection of source and occurrence information of 

chromium-6 data. With this preface, ACWA recommends that EPA include both chromium-6 and 

total chromium in the UCMR3 nationwide Assessment Monitoring (List 1).

ACWA supports monitoring for chromium-6 and total chromium at the EPTDS and DSMRT 

locations to provide EPA with occurrence data to evaluate if chromium-3 is oxidized to chromium-6 

in the presence of an oxidant (e.g., chlorine, ozone, etc.) and to assess the feasibility of using total 

chromium as a monitoring surrogate for chromium-6 (less costly analysis and avoids the short 

holding time required for chromium-6 analysis).

In the interim of release of the final National Toxicity Program (NTP) report, including chromium-6 

and total chromium in the UMCR3 program will be timely to provide occurrence information that 

will be needed in the MCL setting process. Monitoring during the 2013-2015 period will avoid delays 

to secure nationwide occurrence data if a regulatory determination to establish an MCL for 

chromium-6 is needed based on the final NTP report on the human health assessment and exposure 

to chromium-6.
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January 2012

38100 Chromium-6 Page 315 of 401

We also encourage EPA to review and utilize the existing database for total chromium to determine 

if it can provide useful occurrence data. While we do support the inclusion of total chromium and 

chromium-6 in UCMR3 as a one-time exception, ACWA believes that reviewing monitoring data 

already collected would also assist EPA in its efforts.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31897

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 37000 Viruses; 38200 Total Chromium

Comment: *Information gained from the limited, narrow virus focus by monitoring select 800 

small systems using undisinfected groundwater will not provide meaningful data to benefit and 

support the overall UCMR goals to provide information for future regulatory decision-making in 

contrast to the benefits potentially gained by including chromium-6 and total chromium in UCMR3. 

The value gained by testing for chromium-6 and total chromium provides national occurrence 

information that will be meaningful for EPA to determine if regulation may be warranted and far

outweighs the data gathering information for Pre-Screening testing for viruses. 

ACWA appreciates the opportunity to review and comment on the proposed UCMR3 program. If 

you have questions or need further information, please contact me at 916- 441-4545 or ACWA’s 

UCMR3 Workgroup Chair, Nira Yamachika with Orange County Water District, at 714-378-3200.

Sincerely,

Danielle Blacet Senior Regulatory Advocate 

Response: EPA believes that virus monitoring under UCMR 3 will be useful because there are a 

large number of small systems serving untreated water but there is very little information regarding 

virus occurrence in these systems.

EPA will monitor for enteroviruses and noroviruses under UCMR 3 as Pre-Screen Testing. PreScreen Testing is designed to address contaminants with analytical methods that are in an early stage 

of development for use at a limited number of systems determined to be most vulnerable to the 

targeted contaminants.

Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31915
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

38100 Chromium-6 Page 316 of 401

Comment Code: 38100

Comment: Comments on Potential Inclusion of Hexavalent Chromium in UCMR3 

The USEPA is now considering whether to develop a drinking water standard for hexavalent 

chromium because it is now known that hexavalent chromium is carcinogenic by the oral route 

relevant to drinking water exposures, in addition to its long-established inhalation carcinogenicity. 

The current MCL, which is based on older data on non-carcinogenic effects of hexavalent 

chromium and applies to total chromium (trivalent plus hexavalent), is not protective for 

carcinogenicity of hexavalent chromium. The NJDEP recommends adding hexavalent chromium to 

the UCMR3 in order to determine whether hexavalent chromium occurs in public drinking water 

supplies at frequencies and concentrations indicating that a federal standard is needed.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31917

Comment Code: 38100

Comment: Available information suggests that some types of disinfection may influence Cr(VI)-

Cr(III) redox chemistry. It would be ideal to analyze hexavalent chromium in raw and finished water 

as part of UCMR3 monitoring. Information on the concentrations of other metals would also be of 

value because they may have an effect on the species of chromium that is present. Also, in a research 

study currently being conducted by NJDEP on occurrence and formation of hexavalent chromium 

in drinking water, we are collecting ancillary information on; pH, dissolved oxygen, specific 

conductance, turbidity, oxidation/reduction potential, total chromium and total manganese to 

determine the influences on the oxidative form of chromium present and the potential for the 

chromium oxidation to hexavalent chromium. Although it may not be possible to evaluate all of 

these parameters as part of UCMR3 monitoring, it is recommended that, at a minimum, information 

be obtained on the type of disinfection used on the samples analyzed for hexavalent and total 

chromium. This information could be used to determine whether the type of disinfection impacts 

the percentage of the hexavalent form when chromium is present in the drinking water.. 

Response: Please see response to comment code 38100 Chromium-6.

EPA is also requiring PWSs to report all of the types of disinfectants that they are using and, if they 

are using hypochlorite solutions, additional information on whether that hypochlorite solution is 

generated in-house or is purchased from an off-site vendor. 

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31919

Comment Code: 38100
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

38100 Chromium-6 Page 317 of 401

Comment: USEPA requested suggestions as to which contaminant included in the proposed 

UCMR3 could be removed if hexavalent chromium is added. Based on the information presented in 

the comments on specific contaminants above, the NJDEP specifically recommends that 1,2,3-

trichloropropane, the listed perfluorinated chemicals, 1,4-dioxane, and 1,1-dichloroethane remain on 

the final UCMR3 list. The NJDEP does not have experience with some of the other chemical 

contaminants listed in the proposed UCMR3, and thus cannot suggest a specific contaminant to be 

removed. It is recommended that this decision be made by USEPA based on evaluation of the 

information which has been compiled as part of the background for the CCL3 and UCMR3 

processes on the potential health effects and occurrence of these other listed contaminants. 

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2583-2587.

Staat, M.A., G. Fairbrother, K.M. Edwards, M. Griffin, P.G. Szilagyi, G.A. Weinberg, C.B. Hall, 

C.A. Panozzo, D.C. Payne, J.E. Tate, H.A. Clayton, A.L. Fowlkes, M. Wang, A.T. Curns, J. Gentsch, 

M.M. Cortese, M. Patel, M.A. Widdowson, and U. Parashar (2008). "Delayed Onset and Diminished 

Magnitude of Rotavirus Activity-United States, November 2007-May 2008," Morbidity and Mortality 

Weekly Rept., vol. 57, no. 25, pp. 697-700.
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38100 Chromium-6 Page 320 of 401

USEPA (2006). "National Primary Drinking Water Regulations: Ground Water Rule; Final Rule," 

Fed. Reg., vol. 71, no. 216, pp. 65574-67427.

USEPA (2009). 1,2,3-Trichloropropane (CASRN 96-18-4). USEPA IRIS. 9/30/09.

http://www.epa.gov/iris/subst/0200.htm 

USEPA (2010). Paradigm for Addressing Drinking Water Contaminants As Groups to Enhance 

Public Health Protection - EPA Draft Discussion Paper. 

http://water.epa.gov/lawsregs/rulesregs/sdwa/dwstrategy/upload/contaminant_group 

s_paradigm_discussion_9_17_10.pdf 

USEPA (2011). "Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for 

Public Water Systems; Proposed Rule," Fed. Reg., vol. 76, no. 42, pp. 11713-11737.

Winslow SD, Pepich BV, Martin JJ, Hallberg GR, Munch DJ, Frebis CP, Hedrick EJ, Krop RA. 

(2006). Statistical procedures for determination and verification of minimum reporting levels for 

drinking water methods. Environ Sci Technol. 1;40(1):281-8.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Yone Akagi

Commenter Organization: City of Portland, Oregon 

Letter ID: 0088

Comment ID: 31998

Comment Code: 38100

Comment: Thank you for the opportunity to submit the attached comments on the Revisions to 

the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems.

May 2, 2011 Water Docket, EPA Docket Center Environmental Protection Agency Mail Code 

282211T 1200 Pennsylvania Avenue, NW Washington, DC 20460 Attention Docket ID No. OW2009-0090 Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public 

Water Systems Submitted to OW-Docket@epa.gov

Dear Sir or Madam:

The City of Portland, Oregon, Water Bureau appreciates the opportunity to review and provide 

comments on the Unregulated Contaminant Monitoring Regulation (UCMR3); Proposed Rule, 

released on March 3, 2011. We have reviewed this proposed rule from our perspective as a 

chloraminated surface water system with a groundwater system used intermittently. Portland also 

provides water to 19 consecutive systems.

1. EPA requested comment whether to include Cr-VI (using method 218.6) as one of the 30 

contaminants for UCMR 3 Assessment monitoring. 

We support EPA's proposal to include Cr-VI monitoring if after the IRIS assessment is final, EPA 

determines more occurrence data is needed to support rulemaking. The UCMR, with an approved 
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method to gather that data and central reporting is an excellent mechanism to provide the data. 

From a utility point of view, the IRIS assessment and the nationwide sampling effort would provide 

context for communicating this issue to customers. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32036

Comment Code: 38100

Comment: If there are any difficulties with this transmission please contact Steve Via at 202-326-

6130 or svia@awwa.org. Thank you.

May 2, 2011 Water Docket United States Environmental Protection Agency Mail Code 282211T

1200 Pennsylvania Avenue, N.W. Washington, DC 20460 Attention: Revisions to the Unregulated 

Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems, Docket ID No. OW2009-0090

Dear Sir or Madam:

The American Water Works Association (AWWA) is an international, nonprofit, scientific and 

educational society dedicated to the improvement of drinking water quality and supply. Founded in 

1881, the Association is the largest organization of water supply professionals in the world. Our 

54,000-plus members represent the full spectrum of the drinking water community: treatment plant 

operators and managers, environmental advocates, scientists, academicians, and others who hold a 

genuine interest in water supply and public health. Our membership includes more than 4,000 

utilities that supply roughly 80 percent of the nation's drinking water. Protecting public health is an 

essential goal of the drinking water profession and the mission of each public water system. 

AWWA supports the Safe Drinking Water Act (SDWA) framework for the development of national 

drinking water regulations. The SDWA framework includes the Unregulated Contaminants 

Monitoring Rule (UCMR) as the appropriate methodology for collecting a robust national dataset of 

contaminant occurrence to support regulatory decision-making. AWWA reviewed the proposed 

UCMR3 and supports the fundamental components of the agency’s proposal. We also have specific

recommendations for revising the final UCMR3 to facilitate better quality data and reduce the 

burden on water systems and laboratories generating the UCMR data. In summary, those 

recommendations are:

1. Including hexavalent chromium monitoring in the final UCMR3 if the agency’s assessment of 

associated health risk supports its inclusion. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas W. Curtis
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38100 Chromium-6 Page 322 of 401

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080

Comment ID: 32061

Comment Code: 38100

Comment: 3. Whether the Agency should include chromium-6 and total chromium among the 30 

contaminants for UCMR 3 Assessment Monitoring. 

AWWA recommends that EPA include hexavalent chromium (Cr-6) as one of the 30 monitored 

analytes in UCMR3 if the agency’s assessment of associated health risk supports its inclusion. By 

doing so, a robust, nationally representative data set will be developed sufficient to make an 

informed regulatory determination. Cr-6 is a special case in that while total chromium is a regulated 

contaminant, and this standard is regulated based specifically on the risk associated with Cr- 6, Cr-6 

is, itself, not currently regulated and therefore eligible for monitoring within the unregulated 

contaminant monitoring provisions of the Safe Drinking Water Act (SDWA).

If Cr-6 is included in the final UCMR3 monitoring, several questions need to be addressed in the 

final rule, including:

1. What is the appropriate method?

2. Where samples should be drawn? 

3. Is the UCMR dataset adequate for all of the relevant regulatory decision- making questions? 

4. Which "List" should Cr-6 be included in? 

Assuming the IRIS Toxicological Review for Cr-6 sets the stage for a nanogram per liter drinking 

water equivalent level (DWEL), then the current EPA Method requires revision to incorporate 

method modifications necessary to achieve reliable observations in this range. In order to reliably 

calculate a method reporting level, data using this updated method from multiple laboratories will be 

needed. EPA should thus do multi-laboratory LCMRL study for Cr-6 before establishing an MRL. 

EPA needs to be sure the protocols reflect the desired endpoint - e.g. is there a need for field

filtration?

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32063

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: Total Chromium - While a dataset based on the UCMR3 data collection protocol will be 

central to characterizing national occurrence of Cr-6, it will not answer all of the questions relevant 

to a regulatory decision-making process. Ancillary databases will need to be developed that:
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1. Provide a basis to determine what fraction of total chromium is present as Cr-6 in treated water 

and in water once it has been distributed; 

2. Characterize the relative contributions of the various sources of Cr- 6 (e.g., source water as Cr-6, 

source water Cr-3 that is converted to Cr-6 in treatment, Cr-3 and Cr-6 that is introduced to 

drinking water through treatment chemicals and materials, etc.); and

3. Inform developing appropriate treatment options to reduce Cr-6 exposure. 

The question of what fraction of Cr-6 is present as total chromium is very relevant to EPA decisionmaking as the current total chromium MCL is based on health risk associated with Cr-6. Future 

EPA regulatory decisions regarding Cr- 6 must address whether management of total chromium is 

an appropriate strategy to manage Cr-6 or not. Information to describe the relationship between 

total chromium, treatment, and Cr-6 reaching the customer is very important, sufficiently so that it is 

best developed in a way that allows detailed evaluation of the data generated, rather than the 

UCMR3 framework.

Response: Many of the issues raised in this comment are more appropriately addressed if and when 

any future regulatory determinations are made concerning chromium regulations. EPA agrees that 

there are limitations on the research related questions that can addressed in UCMR. However, the 

occurrence data in both EPTDS and DSMRT will provide EPA with a valuable dataset that is 

essential to the determination of possible regulatory actions. 

Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32065

Comment Code: 38100

Comment: 4. EPA requests comments on what contaminant(s) should be removed from the list of 

30 UCMR 3 contaminants if chromium-6 were added, as well as comments regarding the 

recommended and alternative analytical method(s) and the appropriate reporting level. EPA also 

requests comments on whether total chromium should also be measured concurrent with 

chromium-6.

What analyte should be removed to make room for Cr-6? - AWWA previously commented on the 

lack of transparency, as to why particular groups of compounds were included in the UCMR3 over 

others that were on CCL3. That prioritization is central to determining what is least relevant 

compared to Cr-6, and the answer changes based on the key criteria employed. Criteria immediately 

available for this decision-making process include: the need for the data to support SDWA 

regulatory decisions, health significance, likelihood of occurrence, and monitoring cost. The 

following table is a brief illustration of how these criteria are relevant to some of the analytes 

included in the proposed UMCR3. Looking just at the analytes included as part of EPA Method 539, 
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two were not on CCL3, the agency’s latest summary of those analytes that warrant data collection to 

inform whether regulation under SDWA should be considered. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32070

Comment Code: 38100

Comment: EPA could consider other criteria such as data quality concerns associated with

particular methods. As noted previously, among the proposed UCMR3 analytes at the proposed 

MRLs, the analytes measured by EPA Method 539 are the most prone to quality control challenges 

because of the low MRLs. AWWA’s response to the agency’s request for comment on the analytical 

methods proposed and associated MRLs illustrates additional challenges in understanding the quality 

of data obtained using the proposed UCMR3 analytical methods. 

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32073

Comment Code: 38100

Other EPA Comment Codes and Descriptions: 38200 Total Chromium

Comment: Should total chromium be measured concurrently with Cr-6? -- Information to describe 

the relationship between total chromium, treatment, and Cr-6 reaching the customer is very 

important, sufficiently so that it is best developed in a way that allows detailed evaluation of the data 

generated. Based on past experience, focused research projects rather than the UCMR monitoring 

framework likely provide a better opportunity for discerning this relationship and its impact on risk 

management options. 

Response: Please see response to comment code 38100 Chromium-6.
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Comment Code: 38110 EPA Method 218.7 - Chromium-6 

Individual Comments

Commenter Name: Dennis O'Sullivan

Commenter Organization: DoD Safe Drinking Water Act Services Steering Committee

Letter ID: 0048

Comment ID: 31614

Comment Code: 38110

Comment: Page # (FR Notice/ Method): FR: 11718 Para#/ Line# (Methods documents): Section 

III.B.; par.2, line 15 Comment Classification C/M/S/A: S 

Comment: "Modified EPA Method 218.6" is unclear and requires explanation. 

Rationale: In what way(s) will the method be modified and how will this impact sampling 

requirements? 

Response: 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 manufacturer's laboratories 

as well as through external laboratory validation. This method relies on the same instrumentation 

and chemistry as used in Method 218.6, a widely used method for the analysis of chromium-6. The 

primary revisions address the buffers used in analyte preservation and the length of the sample 

holding time. Method 218.7 provides additional flexibility and extended sample holding times as 

compared to Method 218.6. 

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31623

Comment Code: 38110

Comment: There are also concerns with modified Method 218.6. It is not clear from EPA guidance 

whether laboratories should report hexavalent chromium results to a reporting limit (RL) or to a 

method detection limit (MDL). It is important to know the uncertainty around the reported value 

(especially at such a low number), and neither Method 218.6 nor the modified version of the method 

address that. If the laboratories are to report to an MDL, there is a high degree of uncertainty 

associated with the value. Reporting to an RL does lower the uncertainty, but unless a QC sample is 

run at the RL, there is still an undetermined degree of uncertainty. 
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Additionally, the Dionex Application Note for modified Method 218.6 states that the calibration 

curve is linear over the range of 0.1 to 10 ppb. When Dionex was developing the modification, they 

ran standards from 0.04 ppb on up, and there must have been good reasons for determining that the 

linear range started at 0.1 ppb. Dionex determined the MDL by running the 0.1 ppb standard, and 

states that shows the system can support a reporting limit of 0.06 ppb." However, there is no 

requirement in the application note to demonstrate accuracy at that level. The LFB in the modified 

method is at 10 ppb. That LFB concentration is rather high to truly assess the quality of data at the 

reporting limit. There should be a requirement that a QC standard should be run at the reporting 

limit with some required recovery limits that help define the uncertainty of the result. These could 

either be a percent recovery (for example 70 to 130%) or an "absolute" ± value (for example 0.06 ± 

0.02 ppb). That requirement should hold true for whatever method a laboratory uses.

If EPA adds hexavalent chromium to the UCMR list, it should determine the actual laboratory 

capacity available and should also consider a performance based approach to the analysis in which 

the analytical method is not specified but the data quality objectives are specified.

Response: 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 manufacturer's laboratories 

as well as through external laboratory validation. This method relies on the same instrumentation 

and chemistry as used in Method 218.6, a widely used method for the analysis of chromium-6. The

primary revisions address the buffers used in analyte preservation and the length of the sample 

holding time. Method 218.7 provides additional flexibility and extended sample holding times as 

compared to Method 218.6. 

Commenter Name: Deborah H. Metz 

Commenter Organization: Greater Cincinnati Water Works (GCWW)

Letter ID: 0085

Comment ID: 31708

Comment Code: 38110

Comment: 3. Inclusion of hexavalent chromium monitoring 

a. We do support monitoring for hexavalent chromium with a caveat that method 218.6 must be 

updated and verified through round-robin laboratory testing with strict QA/QC controls including 

method recovery issues. The Lowest Concentration Minimum Reporting Level (LCMRL) must be at 

such level that it would not lead to false positives or negatives and is practical for laboratories to 

obtain. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31768
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Comment Code: 38110

Comment: Cr-VI analytical method and reporting level

There are many outstanding questions about the Cr-VI method identified in EPA’s January 2011 

guidance. Several AMWA members have been unable to find a laboratory in their state capable of 

performing the analyses recommended in EPA’s guidance, indicating that the method is not 

commonly used in drinking water laboratories.

Including Cr-VI on UCMR will require EPA to standardize the method and definitively answer 

outstanding questions about the method, including sample holding time and MRL and sample 

preservation. It will also require the agency to accredit laboratories to perform the analyses and 

ensure a more regional laboratory capacity for Cr-VI monitoring. 

Therefore if EPA elects to include Cr-VI on the UCMR-3 list, the agency must ensure that the 

method selected is sufficiently re-evaluated and revised and that the laboratory capacity is adequate. 

If laboratory capacity is expected to be limited then EPA should include Cr-VI as a List 2 

contaminant. 

Response: 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 manufacturer's laboratories 

as well as through external laboratory validation. This method relies on the same instrumentation 

and chemistry as used in Method 218.6, a widely used method for the analysis of chromium-6. The 

primary revisions address the buffers used in analyte preservation and the length of the sample 

holding time. Method 218.7 provides additional flexibility and extended sample holding times as 

compared to Method 218.6. 

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31792

Comment Code: 38110

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: B. Inclusion of hexavalent chromium in the proposed list (FR-p. 11718)

DEP recommends that EPA include hexavalent chromium (Cr+VI) as one of the 30 monitored 

analytes in UCMR-3 if the agency's assessment of associated health risk supports its inclusion. By 

doing so, a robust, nationally representative data set will be developed sufficient to make an 

informed regulatory determination. However, several questions need to be addressed in the final rule

(and hopefully subject to at least additional public comment) regarding the appropriate method and 

the required MRL. Since these questions cannot be answered now, DEP recommends that perhaps 

EPA consider moving Cr+VI to Tier 2- for a screening level assessment.
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EPA has yet to make a final determination on whether Cr+ VI is a potential human carcinogen 

through the oral route of exposure, and if so, the appropriate cancer slope factor to use to estimate 

the potential carcinogenic risk for lifetime exposure through drinking water. This information is still 

in draft stage and has not been reviewed by the Science Advisory Board. The information is needed 

to help determine the need for, and priority to be given to, testing for Cr+ VI in the ng/L range 

suggested by EPA guidance, and in addition, the appropriate methods and MRL to use. 

Of note, DEP analyzed samples for Cr+VI using a contract laboratory in California and following 

EPA's January 2011 guidance and found no Cr+VI at an MRL of 0.05 ug/L. However, based on our 

experience, it is DEP's understanding that additional work is required on the part of EPA to 

standardize the method and definitively answer outstanding questions about the method, including 

sample holding time and MRLs. Laboratory capacity may also be an issue. Overall, DEP believes 

that Cr+VI should be included in UCMR-3, but perhaps in Tier 2 rather than Tier 1. 

Response: Please see response to comment code 38100 Chromium-6.

Since this method relies on the same instrumentation and chemistry as Method 218.6, a method that 

has been extensively used throughout the commercial laboratory community, and since EPA has 

extended the sample holding time, EPA feels that laboratory capacity will not be an issue. Therefore, 

the monitoring of chromium-6 is best accomplished as a List 1 analyte.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31813

Comment Code: 38110

Comment: We are concerned when potential national primary contaminants are advanced outside 

of this scientific and agreed upon regulatory process. Moreover, we are aware that chromium-6 

analysis likely requires the implementation of a modified version of EPA Method 218.6. We 

encourage the EPA to provide additional guidance to laboratories and PWSs regarding field pH 

adjustments, field pH confirmation, analysis within 24 hours of sample collection, post-column 

derivatization and necessary equipment, and other issues which may cause high sample rejection 

rates and inaccurate results.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31852

Comment Code: 38110

Comment: 7.2 Chromium-6 Analytical Method
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On January 11, 2011, the Assistance EPA Administrator Peter Silva issued "Guidance for Public 

Water Systems on Enhanced Monitoring for Chromium-6 (Hexavalent Chromium) in Drinking 

Water" in response to several key events occurring since fall 2010 and Administrator Lisa Jackson’s 

commitment to address chromium-6. The EPA guidance recommended several analytical methods 

to monitor for chromium-6 at a lower detection limit (< 1 ug/L), including using a modified version 

of EPA Method 218.6, "Determination of Dissolved Hexavalent Chromium in Drinking Water, 

Groundwater and Industrial Wastewater Effluents by Ion Chromatography" (Rev. 3.3, 1994; 

www.nemi.gov). As noted in Section 7.1, CA’s UCMR conducted in 2001-2002 required analysis for 

chromium-6 using EPA Method 218.6 at a detection limit for reporting purposes (DLR) of 1 ug/L. 

Modified method 218.6 appears to be an appropriate analytical method for consideration in the 

UCMR3 analytical methods for chromium-6 analysis.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31895

Comment Code: 38110

Comment: 7.2 Chromium-6 Analytical Method

On January 11, 2011, the Assistance EPA Administrator Peter Silva issued "Guidance for Public 

Water Systems on Enhanced Monitoring for Chromium-6 (Hexavalent Chromium) in Drinking 

Water" in response to several key events occurring since fall 2010 and Administrator Lisa Jackson’s 

commitment to address chromium-6. The EPA guidance recommended several analytical methods 

to monitor for chromium-6 at a lower detection limit (< 1 ug/L), including using a modified version 

of EPA Method 218.6, "Determination of Dissolved Hexavalent Chromium in Drinking Water, 

Groundwater and Industrial Wastewater Effluents by Ion Chromatography" (Rev. 3.3, 1994; 

www.nemi.gov). As noted in Section 7.1, CA’s UCMR conducted in 2001-2002 required analysis for 

chromium-6 using EPA Method 218.6 at a detection limit for reporting purposes (DLR) of 1 ug/L. 

Modified method 218.6 appears to be an appropriate analytical method for consideration in the 

UCMR3 analytical methods for chromium-6 analysis. Note: CDPH is still reviewing its existing DLR 

(detection limit for purposes of reporting) in response to the January EPA guidance and modified 

method 218.6. While we agree with the method chosen for monitoring chromium-6, there are still 

uncertainties regarding the appropriate detection limit to ensure reliable results and accurate 

occurrence data.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31918

Comment Code: 38110
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Comment: In the proposed UCMR3, the USEPA references the recent voluntary guidance for

hexavalent chromium which recommended a modified version of USEPA Method 218.6 and has a 

recommended reporting level of 0.06 μg/L. The USEPA is also requesting comments on this 

recommended method and any alternative methods, and the appropriate reporting level. Recent 

information indicates that modifications to USEPA Method 218.6 improve the method sensitivity 

limit for hexavalent chromium to 0.001 μg/L. More information on this subject will be available 

during a Webinar sponsored by Dionex on May 10, 2011 at 11 AM EST. See 

http://www.dionex.com/en-us/events/webinars/lp-110581.html

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32071

Comment Code: 38110

Comment: Analytical Methods for Cr-6 -- Assuming the IRIS Toxicological Review for Cr-6 sets 

the stage for a nanogram per liter drinking water equivalent level (DWEL) then the current EPA 

Method requires revision to incorporate method modifications necessary to achieve reliable 

observations in this range. In order to reliably calculate a method reporting level, data using this 

updated method from multiple laboratories will be needed. EPA should thus do multi-laboratory 

LCMRL study for Cr-6 before establishing an MRL. EPA needs to be sure the protocols reflect the 

desired endpoint - e.g. is there a need for field filtration?

Response: Please see response to comment code 38100 Chromium-6.
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January 2012

38120 Other Methods - Chromium-6 Page 331 of 401

Comment Code: 38120 Other Methods - Chromium-6 

Individual Comments

Commenter Name: Lori Mathieu

Commenter Organization: Drinking Water Section, Connecticut Department of Public Health 

(CTDPH)

Letter ID: 0050

Comment ID: 31622

Comment Code: 38120

Comment: Screening could be a cost-effective way to rule out samples that do not need the 

definitive analytical procedures. For example, the CT DPH Laboratory investigated a collision cell 

ICP/MS screening method for total chromium, and got excellent recoveries at 0.06 ppb, the 

recommended reporting level. If the screening results show total chromium above the levels of 

concern, then those samples could be reanalyzed using a definitive method. Others have suggested

HPLCIICPIMS as another way to speciate the various forms of chromium and others have also 

suggested that the manual spectrophotometric method could be optimized to achieve the required 

reporting limits in drinking water.

Response: EPA has approved Method 200.8 (ICP/MS) and the ASTM and Standard Methods 

equivalent methods for the analysis of total chromium. 

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 manufacturer's laboratories as well as 

through external laboratory validation. This method relies on the same instrumentation and 

chemistry as used in Method 218.6, a widely used method for the analysis of chromium-6. The 

primary revisions address the buffers used in analyte preservation and the length of the sample 

holding time. Method 218.7 provides additional flexibility and extended sample holding times as 

compared to Method 218.6. The estimated cost of these analyses is too low to justify the use of an 

equivalently priced screening method. 
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Comment Code: 38130 Sampling Location - Chromium-6 

Summary Response to Comments on Sampling Location - Chromium-6: Monitoring for both 

total chromium and chromium-6 will be required under UCMR 3 at both the EPTDS and DSMRT 

sampling locations. EPA agrees that, given the type of sampling conducted in UCMR, the agency 

will not be able to interpret paired EPTDS and DSMRT data for chromium from specific PWSs. 

That could only be determined using a research project designed to determine transit times and 

booster disinfection locations within each distribution system. Nonetheless, EPA believes that the 

data set as a whole will provide valuable insight. The purpose of UCMR is to determine the 

proportion of the population that may be exposed to a specific contaminant at specific 

concentrations. Since there is a potential difference in the concentration of chromium-6 between 

EPTDS and DSMRT, having data from both points will provide EPA with better estimations of 

concentrations and populations exposed, than estimations based on sampling at only one of these 

locations.

Individual Comments

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority

Letter ID: 0062

Comment ID: 31656

Comment Code: 38130

Comment: If sampling for hexavalent chromium is required in UCMR-3, MWRA recommends that 

samples be collected at the Entry Point to the Distribution System (EPTDS). While it might seem 

useful to also collect samples within the distribution system to attempt to develop some information 

about conversion of total chromium to hexavalent chromium under oxidizing conditions, we do 

NOT recommend it. A more scientifically supportable answer would be obtained if the EPTDS data 

were supplemented by research projects structured to investigate the mechanisms of formation in an 

organized manner. 

Response: Please see response to comment code 38130 Sampling Location - Chromium-6.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31752

Comment Code: 38130

Comment: 15. With regard to sample locations for Cr6+ we believe that it makes sense to sample 

only at the EPTDS, because the complexities of interpreting DSMRT data for Cr6+ compared to 

EPTDS samples cannot be resolved with only a limited number of paired samples, especially 

considering that some utilities may use booster chlorination (which could provide for additional 

oxidation of Cr3+ to Cr6+ ) while others do not. In the event that EPA elects to have samples 

collected at the DSMRT for Cr6+ it will be essential to gather good information on distribution 
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system disinfection practices, and the UCMR3 database is not currently configured to collect that 

kind of data. 

Response: The purpose of UCMR is to determine if there is sufficient occurrence of a contaminant 

at levels of health concern to justify proceeding to develop a drinking water regulation. Since we 

know that chromium-3 will oxidize to chromium-6 in the presence of typically used drinking water 

disinfectants, EPA feels that it is important to know the concentrations of chromium-6 at both the 

entry point and longest residence time locations. A detailed understanding of oxidation rates, 

presence of booster systems, or other related costly research items are not needed to make a 

regulatory decision. 

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31793

Comment Code: 38130

Comment: DEP supports testing for Cr+VI at a distribution sampling point of maximum residence 

time ("DSMRT"). This might provide some useful information on changes in the valence state of 

Cr+VI in systems using strong oxidants for disinfection. 

Response: Please see response to comment code 38130 Sampling Location - Chromium-6.

Commenter Name: David Lipsky

Commenter Organization: New York City Department of Environmental Protection (DEP)

Letter ID: 0096

Comment ID: 31798

Comment Code: 38130

Other EPA Comment Codes and Descriptions: 35050 Sampling Location - Chlorate 

Comment: E. Metals samples at distribution system maximum residence time location (76 FR

11723)

DEP believes that the only compounds within UCMR-3 that should be analyzed at DSMART are 

those constituents that are either disinfection byproducts or metals that are more toxic in the 

oxidized state. Of the UCMR list metals, DEP would support assessing Cr+VI at DSMRT, if 

included in UCMR-3, and chlorate as a disinfection byproduct.

Response: Please see response to comment codes 38130 Sampling Location - Chromium-6 and 

34010 EPA Method 200.8 Rev 5.4 - Metals.

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31838
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Comment Code: 38130

Other EPA Comment Codes and Descriptions: 38250 Sampling Location - Total Chromium 

Comment: Riverside also supports monitoring for chromium-6 and total chromium at the EPTDS 

and DSMRT locations to provide EPA with occurrence data to evaluate if chromium-3 is oxidized 

to chromium-6 in the presence of an oxidant (e.g., chlorine, ozone, etc.) and to assess the feasibility 

of using total chromium as a monitoring surrogate for chromium-6 (less costly analysis and avoids 

the short holding time required for chromium-6 analysis).

Response: Please see response to comment code 38130 Sampling Location - Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32062

Comment Code: 38130

Comment: Typically, UCMR samples are collected at the EPTDS but there are instances (e.g., 

nitrosamines) where a distribution system observation is preferable. Because we know there is 

conversion of Cr-3 to Cr-6 through oxidation, the distribution system observation could be relevant 

to Cr-6. Based on the available information, it appears that that the increase in Cr-6 after the 

EPTDS can make a small contribution to total Cr-6 occurrence.[FN11: 2004, Frey, M.M., Seidel, C., 

Edwards, M., Parks, J.L., McNeill, L.. Occurrence Survey of Boron and Hexavalent Chromium. 

Awwa Research Foundation.] However, the nature of the UCMR sampling structure is such that it is 

unlikely UCMR3 data would inform our understanding of this contribution. Consequently, if Cr-6 is 

monitored, AWWA recommends monitoring only at the EPTDS. A dataset based on EPTDS 

samples would be the most readily understood and utilized by the agency, particularly if it were 

supplemented by research projects structured to investigate the mechanisms of formation in an 

organized manner. 

Response: Please see response to comment code 38130 Sampling Location - Chromium-6.
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Comment Code: 38200 Total Chromium

Individual Comments

Commenter Name: 

Commenter Organization: Northern Kentucky Water District

Letter ID: 0060

Comment ID: 31647

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: Although there has been ongoing public concerns about chromium-6 and the possible 

occurrence in the public water supply, it would be an appropriate recommendation to add Cr-6 to 

UCMR3 list as opposed to having Congress draft more aggressive legislation to immediately regulate 

this compound. It should be added to follow the usual procedure for a contaminant regulation. The 

data collected from UCMR3 will provide good data as to whether Cr-6 is a concern and should be 

regulated. With the increased public concern this has encouraged the commercial labs to look into 

the analysis of Cr-6. By the time the UCMR3 is in effect, there may be enough certified labs to cover 

the additional Cr-6 monitoring. The addition of Total Chromium to the UCMR3 list would not 

follow the typical procedure for the UCMR since Total Chromium is already a regulated

contaminant. It could be a strong recommendation, from EPA, to have utilities do a side-by side 

analysis of total chromium for the potential of a surrogate. If the Utilities were aware that the 

possible use of a surrogate for compliance would be less of a financial burden for cost of analysis, 

they might be willing to participate in the additional monitoring for total chromium during the 

UCMR3.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority 

Letter ID: 0062

Comment ID: 31657

Comment Code: 38200

Comment: EPA also asked whether total chromium data should also be collected as part of

UCMR-3. EPA will need to substantially improve current total chromium analytical methods if we 

are to be able to develop an understanding of conversion of total to hexavalent chromium, and of 

the relative source contributions from the environment and trace amounts in treatment chemicals. 

Current methods are not sensitive enough, and are too influenced by interferences to be useful. This 

is critical work if the effort spent on data collection is to prove useful in assessing and mitigating any 

potential health risks.

Response: EPA is convinced that the use of ICP/MS methods such as EPA Method 200.8 can 

provide accurate and precise data for the analysis of total chromium at the MRL of 0.2 μg/L, and 
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that these data will provide important data on the correlation between total chromium and 

chromium-6 occurrence.

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31681

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: The State of New Mexico has the following comments on the Revisions to the 

Unregulated Contaminant Monitoring Regulation for Public Water Systems, UCMR3. 

Page 11718

EPA thus requests comment on whether the Agency should include chromium6 as one of the 30 

contaminants for UCMR 3 Assessment Monitoring. 

NMED Comment

New Mexico Environment Department samples community and nontransient noncommunity water 

systems for total chromium. During the 2005 to 2007 compliance period only one result, 83 ppb, 

was within 20 percent of the maximum contaminant level for chromium, 100 ppb. Based on service 

to a population of 100, the system would not be targeted for sampling under UCMR3 if it were an 

active system. The next highest result was 36 ppb. One thousand four hundred thirty eight, 1,438, 

results were considered. Only 27 percent of the results were greater than 5 ppb. Speciation of 

chromium would not benefit the state of New Mexico.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31682

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 36000 Perfluorinated Compounds (PFCs); 

38100 Chromium-6 

Comment: Page 11718

EPA requests comments on what contaminants should be removed from the list of 30 UCMR 3 

contaminants if chromium6 were added, as well as comments regarding the recommended and 

alternative analytical methods and the appropriate reporting level. EPA also requests comments on 

whether total chromium should also be measured concurrent with chromium6. 

NMED Comment
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If chromium6 is added, it should be measured concurrent with total chromium. If chromium6 were 

added, deletion of either perfluorononanoic acid, PFNA; perfluorohexane sulfonic acid, PFHxS; 

perfluoroheptanoic acid, PFH pA; or perfluorobutane sulfonic acid, PFBS, is recommended. The 

other two perfluorinated chemicals should be monitored in New Mexico because they are used in 

fire fighting. New Mexico is subject to fires in periods of drought and high winds. 

Response: Please see response to comment codes 38100 Chromium-6 and 36000 Perfluorinated 

Compounds (PFCs). 

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action

Letter ID: 0079

Comment ID: 31699

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: Comments on Unregulated Contaminant Monitoring Rule (UCMR3) Proposed 

Revisions.

May 2, 2011 Water Docket U.S. Environmental Protection Agency 1200 Pennsylvania Ave. NW

Washington DC 20460 Attn: Docket ID No. OW-2009-0090

Clean Water Action Comments on the Unregulated Contaminant Monitoring Rule (UCMR 3)

Re: Proposed Rule, Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR #) 

for Public Water Systems (Docket ID No. EPA-HW-OW-2009-0090)

We appreciate the opportunity to comment on the U.S. Environmental Protection Agency’s (EPA) 

Proposed Revisions to the Unregulated Contaminant Monitoring Rule (UCMR 3).

Clean Water Action is a national citizens’ organization of 1.2 million members and is active in over a 

dozen states. Clean Water Action works for strong public health and environmental protections with 

an emphasis on those that impact water resources. Clean Water Action has a long history of work on 

drinking water and on Safe Drinking Water Act implementation. 

Should EPA Include Chromium-6 in Assessment Monitoring? 

In the Proposed Revisions published March 3, 2011 in the Federal Register, EPA asked for public 

comment on whether chromium-6 should be included in UCMR Assessment Monitoring and 

whether total chromium should be measured concurrently. We support this proposal given growing 

concern about hexavalent chromium in drinking water and increased evidence of public health 

threats which are greater than previsously understood. Understanding occurrence of hexavalent 

chromium offers an opportunity to reduce public health risk for those served by Public Water 

Systems.
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While we recognize that EPA has initiated a voluntary program in which many Public Water 

Systems are monitoring for this contaminant, the UCMR data can provide a more robust data set 

and assist in understanding the actual occurrence of chromium-6 nationwide in different types of 

source water and in different sizes of systems. Concurrent monitoring for total chromium makes 

sense in light of the need to understand both relative occurrence and whether total chromium is an 

appropriate surrogate. 

We also recognize that EPA’s Toxicological Review of Hexavalent Chromium will be completed this 

year and will prompt a review of the current MCL for Total Chromium. We urge EPA not to delay 

any regulatory determination indicated by the Toxicological Review.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Eddy So 

Commenter Organization: San Francisco Public Utilities Commission

Letter ID: 0082

Comment ID: 31704

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 34400 Strontium ; 38100 Chromium-6 

Comment: Inclusion of Hexavalent Chromium in UCMR3 We support the inclusion of hexavalent

chromium as one of the 30 contaminants for Assessment monitoring in the final UCMR3. We also 

believe that concurrent monitoring of total chromium could provide crucial information regarding 

the relative occurrence of these contaminants and help determine in the future whether utilities and 

regulatory agencies should continue the use of total chromium as a surrogate for hexavalent 

chromium. However, we suggest EPA describe in the final UCMR3 what approach, if chosen, 

would be used to characterize the relationship of total chromium as the hexavalent chromium 

surrogate.

If something needs to be removed from the proposed UCMR3 list to make room for hexavalent 

chromium, we suggest excluding strontium for the following reasons: 

- Based on available information from World Health Organization[FN1: World Health 

Organization: Concise International Chemical Assessment Document 77: Strontium and Strontium 

Compounds, 2010], there are data on strontium concentrations at many points in the public water 

system, including entry, various points in the treatment and distribution systems, and finished 

drinking water, and

- It is not a major additive (as compared with molybdenum and vanadium) to alloy steel, so the 

release of strontium is not expected to be more significant than the others. Thus, the inclusion of 

strontium in this round of UCMR3 is less justified than hexavalent chromium and the other three 

inorganic contaminants. 

Regards,
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- Eddy So, P.E.(Civil), P.E.(Mech) Regulatory Workgroup Supervisor Water Quality Division San 

Francisco Public Utilities Commission 1657 Rollins Road Burlingame, CA 94010 Tel: 650-652-3115

Email: eso@sfwater.org

Response: EPA believes that monitoring for strontium is justified. While strontium has a relatively 

high health risk level of 4,200 μg/L, it has previously been detected at high percentages (>90%) in a 

number of water occurrence studies, with upper levels of quantitation at concentrations far 

exceeding this health level. Chromium-6 (hexavalent chromium) and total chromium have been 

added to the list of contaminants to be monitored. In addition, sec-butylbenzene and npropylbenzene have been removed from the list of contaminants to be monitored. Please see 

response to comment code 38100 Chromium-6.

Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31721

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: 4. Chromium and Hexavalent Chromium Monitoring. EPA requests comments on 

whether to include hexavalent chromium (Cr-6) and/or total chromium (Cr) on the list of 30 

contaminants proposed for UCMR3 for Assessment Monitoring. CVWD recommends both Cr-6 

and Cr be included in UCMR3 for assessment monitoring (List 1). While UCMR monitoring should 

be used for unregulated contaminants, CVWD believes that the unique transitional relationship 

between source water Cr levels and Cr-6 levels found in PWS’s that practice disinfection justifies the 

inclusion of the regulated contaminant Cr in UCMR3. Cr monitoring may also represent a cost 

effective, practicable and improved surrogate for monitoring Cr-6 occurrence in PWSs. Water 

agencies in California have already completed comprehensive Cr-6 source water monitoring in 

accordance with California unregulated contaminant monitoring requirements and in many cases 

virtually all of the naturally occurring Cr found in the source water was found in the oxidized form 

as Cr-6. Water agencies with this knowledge can benefit from using the more cost effective and 

practicable Cr test method for future determinations regarding Cr-6 occurrence in drinking water 

sources.

Including Cr and Cr-6 in the UCMR3 is also consistent with recent EPA efforts to improve 

occurrence data for Cr-6. Unlike EPA’s recent recommendation for voluntary enhanced Cr-6 

monitoring, UCMR3 is the right tool for implementing this type of occurrence monitoring. UCMR3 

provides a program that includes a peer reviewed validation process for sample collection and 

analytical methods and provides a centralized database that allows this occurrence data to be used

effectively for regulatory decisions. Including Cr and Cr-6 in UCMR3 allows water agencies to 

combine Cr and Cr-6 monitoring with other chemical monitoring included in UCMR3, which is 

more cost effective and efficient than any "enhanced" single contaminant monitoring campaign. 

Response: Please see response to comment code 38100 Chromium-6.
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Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31722

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 37000 Viruses; 38100 Chromium-6 

Comment: 5. Removing Virus Monitoring. CVWD believes including Cr and Cr-6 monitoring on 

the list of 30 contaminants is more timely and beneficial than the proposed monitoring for two 

viruses (Norovirus and Enterovirus). Test methods for these viruses have not been validated and the 

work by Borchardt used to support virus monitoring has not been peer reviewed. CVWD also 

believes the proposed virus monitoring performed at 800 PWS’s serving less than 1,000 persons 

using undisinfected sources producing groundwater from karst or fractured bedrock formations will 

provide occurrence data of limited value that is not representative of most drinking water served in 

the U.S. Removing monitoring for the two viruses will allow the addition of Cr and Cr- 6 

monitoring without exceeding the prescribed limit of 30 contaminants for UCMR monitoring and 

provide more valuable information for future regulatory decisions. 

Response: Most virus-indicator correlation studies have been performed in disinfected systems. 

UCMR 3 monitoring will specifically focus on undisinfected ground water systems. 

Theoretically, this study could be conducted outside the UCMR 3 program, though EPA believes 

that this effort is far bigger and more complex in scope and funding than a research project can 

achieve. Thus EPA believes that the UCMR 3 is the best mechanism. UCMR 3 will provide 

occurrence data; the main idea is that if occurrence (in sensitive and undisinfected systems) is similar 

on a national scale to that found by Borchardt, exposure and health risks are likely to be similar. 

EPA disagrees that the rationale for conducting virus monitoring under UCMR 3 is weak and 

believes that a national study is warranted based upon the Borchardt data. The virus method EPA is 

using includes all the elements the commenter has suggested except for the multi-laboratory 

validation. However, EPA will be conducting a PT program prior to the monitoring. This will serve 

both as a "multi-laboratory validation" of the method as well as an evaluation of the performance of 

laboratories. Commercial laboratories will be selected based on their performance in a PT study. 

Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31763

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: 4. Chromium and Hexavalent Chromium Monitoring. EPA requests comments on 

whether to include hexavalent chromium (Cr-6) and/or total chromium (Cr) on the list of 30 

contaminants proposed for UCMR3 for Assessment Monitoring. WESTCAS recommends both Cr6 and Cr be included in UCMR3 for assessment monitoring (List 1). While UCMR monitoring 
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should be used for unregulated contaminants, WESTCAS believes that the unique transitional 

relationship between source water Cr levels and Cr-6 levels found in PWS’s that practice disinfection 

justifies the inclusion of the regulated contaminant Cr in UCMR3. Cr monitoring may also represent 

a cost effective, practicable and improved surrogate for monitoring Cr-6 occurrence in PWSs. Water 

agencies in California have already completed comprehensive Cr-6 source water monitoring in 

accordance with California unregulated contaminant monitoring requirements and in many cases 

virtually all of the naturally occurring Cr found in the source water was found in the oxidized form 

as Cr-6. Water agencies with this knowledge can benefit from using the more cost effective and 

practicable Cr test method for future determinations regarding Cr-6 occurrence in drinking water 

sources.

Including Cr and Cr-6 in the UCMR3 is also consistent with recent EPA efforts to improve 

occurrence data for Cr-6. Unlike EPA’s recent recommendation for voluntary enhanced Cr-6 

monitoring, UCMR3 is the right tool for implementing this type of occurrence monitoring. UCMR3 

provides a program that includes a peer reviewed validation process for sample collection and 

analytical methods and provides a centralized database that allows this occurrence data to be used

effectively for regulatory decisions. Including Cr and Cr-6 in UCMR3 allows water agencies to 

combine Cr and Cr-6 monitoring with other chemical monitoring included in UCMR3, which is 

more cost effective and efficient than any "enhanced" single contaminant monitoring campaign. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Randy Gottler

Commenter Organization: City of Phoenix Water Services Department (WSD)

Letter ID: 0091

Comment ID: 31785

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: UCMR Contaminant List - Chromium and Hexavalent Chromium EPA requests 

comments on whether to include hexavalent chromium and/or total chromium on the list of 

contaminants proposed for UCMR 3 for Assessment Monitoring. The WSD supports including 

hexavalent chromium measured concurrent with total chromium to determine the suitability of total 

chromium monitoring as a cost effective and practicable surrogate for monitoring hexavalent 

chromium in public water systems. Unlike voluntary monitoring programs, assessment monitoring 

for UCMR 3 provides peer reviewed validation process for COP WSD Comments on UCMR3 

sample collection and analytical methods plus a centralized database that allows the effective use of 

occurrence data for regulatory decisions regarding hexavalent chromium. In addition, monitoring for 

hexavalent chromium and total chromium with other chemical monitoring included in UCMR 3 is 

more cost effective and efficient than a voluntary monitoring campaign for only hexavalent 

chromium. 

We appreciate the opportunity to provide these comments. Please feel free to contact me at 602-

534-1358 if you have any questions or wish to discuss our comments.

Sincerely,
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Randy Gottler Compliance and Regulatory Affairs Administrator 

c: John Calkins, Arizona Department of Environmental Quality Korissa Entringer, Maricopa 

County Environmental Services Department Carlos Padilla Troy Hayes Stephen Wetherell 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas LaHue 

Commenter Organization: Soquel Creek Water District (SqCWD),

Letter ID: 0094

Comment ID: 31787

Comment Code: 38200

Comment: If EPA includes Cr-6 in UCMR 3, we believe that testing should include total chromium 

as well as Cr-6 and include monitoring distribution system water in addition to source water. This 

will provide valuable information on the source water relationship between total chromium and Cr-6 

and the frequency of oxidation of Cr-3 to Cr-6 by chlorine in the distribution system. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31812

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: The MDH supports the inclusion of both chromium-6 and total chromium as two of 

the 28 new UCMR 3 chemical contaminants designated for Assessment Monitoring under List 1. 

National occurrence data is necessary for any future regulation of chromium-6. We continue to 

support the use of the Contaminant Candidate List (CCL) process as the preferred system for the 

Administrators’ determinations regarding regulation of contaminants in the interest of protecting 

public health, as required under the SDWA section 1412 (b)(1). 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Randy Ellingboe 

Commenter Organization: Minnesota Department of Health 

Letter ID: 0078

Comment ID: 31814

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: In order to provide for chromium-6 and total chromium analysis, we recommend EPA

remove two contaminants using the same criteria used for inclusion: public health concern, 
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occurrence data availability, and analysis method reliability. Furthermore, we recommend EPA 

remove at least one additional similarly-ranked contaminant in order to provide inclusion of at least 

one cyanotoxin. There is an emerging need for collection of occurrence data for cyanotoxins within 

PWSs, as documented within CCL 3 by EPA’s determination of "no comprehensive drinking water 

occurrence data" for three compounds: Anatoxin-a, Cylindrospermopsin, and Microcystin-LR. The 

collection of occurrence data, in combination with EPA’s ongoing quantitative assessments, e.g., 

Integrated Risk Information System (IRIS), will likely aid in PWS cyanotoxin risk determinations. 

Alternatively, these chemicals should be evaluated for inclusion in a potential grouped contaminant 

regulatory decision. 

Response: 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 highperformance 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. In addition, even though high-performance liquid chromatography/tandem mass 

spectrometry (HPLC/MS/MS) methods for cyanobacterial toxins have been published (Oehrle et 

al., 2010), these methods also do not provide suitable accuracy and precision. EPA has conducted 

and will continue to conduct methods development research for cyanobacterial toxins and other 

emerging contaminants both in-house, and in cooperation with other laboratories. 

Please see response to comment code 38100 Chromium-6.

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.

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.

Commenter Name: Mark R. Vickery, P.G.

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087

Comment ID: 31822

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: Hexavalent chromium 

The EPA did not include hexavalent chromium in the proposed UCMR 3 and specifically requested 

comment regarding the possible inclusion of hexavalent chromium in the final UCMR 3 sampling. 

The TCEQ comments that the EPA should strongly consider investigatory sampling for hexavalent 

chromium, if and only if an inexpensive consensus method can be approved before the UCMR 3 

sampling cycle. No analyte should be placed at the top of the CCL prioritization for any reason 

other than sound science. If the EPA believes that it is necessary to perform pre-regulatory sampling 

for hexavalent chromium, the EPA should do a separate rulemaking, or include hexavelent 
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chromium in CCL 4. If, however, the EPA includes hexavalent chromium in UCMR 3, then total 

chromium should be monitored simultaneously. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31837

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: Chromium-6 and Total Chromium 

EPA is requesting comments on whether to include hexavalent chromium (chromium-6) as one of 

the 30 contaminants for UCMR3 for Assessment Monitoring (FR page11718). EPA is also 

requesting comments on whether to include testing for total chromium concurrently with 

chromium-6. Collecting occurrence data for both chromium-6 and total chromium would provide 

information to assess if total chromium could be a viable surrogate for chromium-6.

Although Riverside does not support the inclusion of regulated contaminants (total chromium) in 

the UCMR program, we understand the importance of collecting concurrent total chromium and 

chromium-6 data and do not disagree with including total chromium in the UCMR program. 

Therefore, Riverside recommends that EPA include both chromium-6 and total chromium in the 

UCMR3 nationwide Assessment Monitoring (List 1). 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31839

Comment Code: 38200

Comment: In addition, we also encourage EPA to review and utilize the existing database for total 

chromium to determine if it can provide useful occurrence data. While we do support the inclusion 

of total chromium and chromium-6 in UCMR3, Riverside believes that reviewing monitoring data 

already collected would also assist EPA in its efforts.

Response: EPA agrees that it should review existing, credible sources of monitoring data. The 

agency uses all sources of credible data that can help it understand drinking water contaminants and 

the need and manner of regulation. 

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)
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Letter ID: 0052

Comment ID: 31851

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: 7.0 Chromium-6 and Total Chromium 

EPA is requesting comments on whether to include hexavalent chromium (chromium-6) as one of 

the 30 contaminants proposed for UCMR3 for Assessment Monitoring (FR page11718). EPA is also 

requesting comments on whether to include testing for total chromium concurrently with 

chromium-6. Collecting occurrence data for both chromium-6 and total chromium would provide 

information to assess if total chromium could be a viable surrogate for chromium-6. EPA is also 

requesting comment on the analytical method and appropriate reporting level. 

7.1 Chromium-6 and Total Chromium: Inclusion in UCMR3 

The primary purpose of the Contaminant Candidate List (CCL) and the UCMR program is to 

provide information for EPA to determine which drinking water contaminants have the highest 

potential to provide a meaningful opportunity to reduce health risk by establishing a primary 

drinking water regulation. The CCL process identifies contaminants that are anticipated to occur in 

drinking water, while the UCMR program provides national occurrence information for EPA to 

determine if a contaminant occurs at a frequency and concentration that would be a public health 

concern warranting regulation. Currently, total chromium is an inorganic contaminant that is 

regulated with a primary drinking water standard which includes both chromium-6 and chromium-3. 

There is no primary drinking water standard for chromium-6.

The purpose of the UCMR program is to gather occurrence information for unregulated 

contaminants and in general OCWD would not support the inclusion of regulated contaminants in 

the UCMR cycle. However, OCWD would support inclusion of total chromium and chromium-6 as 

a one time exception in order to expedite the collection of source and occurrence information of 

chromium-6 data. With this preface, OCWD recommends that EPA include both chromium-6 and 

total chromium in the UCMR3 nationwide Assessment Monitoring (the basis of this support is 

described below and summarized in the following table). EPA has a robust, quality-driven procedure 

(approved methods with results that are supported by meeting stringent data quality objectives - for 

nationwide laboratory consistency in reported results) in place by the UCMR program to gather 

nationwide occurrence information for contaminants of potential concern. 

Chromium-6 has received national media attention and enhanced public awareness of the potential 

health risks from chromium-6 exposure, including EPA as demonstrated by their January 2011 

"Guidance for Public Water Systems on Enhanced Monitoring for Chromium-6 (Hexavalent 

Chromium) in Drinking Water." OCWD supports monitoring for chromium-6 and total chromium 

at the EPTDS and DSMRT locations to provide EPA with occurrence data to evaluate if 

chromium-3 is oxidized to chromium-6 in the presence of an oxidant (e.g., chlorine, ozone, etc.) and 

to assess the feasibility of using total chromium as a monitoring surrogate for chromium-6 (less 

costly analysis and avoids the short holding time required for chromium-6 analysis).

Chromium-6 has been a contaminant of interest in CA for over a decade. In 1999, the CA 

Department of Public Health (DPH, formerly CA Department of Health Services (CDHS)) 
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indentified chromium-6 to be included in the CA’s unregulated chemicals requiring monitoring 

(UCMR). CA required analysis for chromium-6 using EPA Method 218.6 at a detection limit for 

reporting purposes (DLR) of 1 ug/L. Monitoring for chromium-6 occurred between January 1, 2001 

and December 31, 2002. CA will be developing a drinking water standard (i.e., MCL) for chromium6 once the CA Office of Environmental Health Hazard and Assessment (OEHHA) finalizes the CA 

Public Health Goal (PHG). Listed on the following table is a summary of the CA’s chromium-6 

timeline to develop a MCL in drinking water and recent national interest in chromium-6, further 

supporting the recommendation to include chromium-6 and total chromium in the final listing of 

UCMR3 chemicals.

[Table: see PDF docket ID EPA-HQ-OW-2009-0090-0052]

Including chromium-6 and total chromium in the list of 30 chemicals for UCMR3 Assessment 

Monitoring is well justified as shown by the chromium-6 timeline of events illustrating the (1) 

potential carcinogenicity of chromium-6 when ingested and (2) nationwide media coverage 

prompting public concerns and raised awareness of the potential harmful health impacts. In the 

interim of release of the final National Toxicity Program (NTP) report, including chromium-6 and 

total chromium in the UMCR3 program will provide timely occurrence information that will be 

needed in the MCL setting process. Monitoring during the 2013-2015 period will avoid delays to 

secure nationwide occurrence data if a regulatory determination to establish an MCL for chromium6 is needed based on the final NTP report on the human health assessment and exposure to 

chromium-6.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31854

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 37000 Viruses; 38100 Chromium-6 

Comment: * Information gained from the limited, narrow virus focus by monitoring select 800 

small systems using undisinfected groundwater will not provide meaningful data to benefit and 

support the overall UCMR goals to provide information for future regulatory decision-making in 

contrast to the benefits potentially gained by including chromium-6 and total chromium in UCMR3. 

The value gained by testing for chromium-6 and total chromium provides national occurrence 

information that will be meaningful for EPA to determine if regulation may be warranted and far

outweighs the data gathering information for Pre-Screening testing for viruses. 

OCWD appreciates the opportunity to review and comment on the proposed UCMR3 program.

Sincerely,

Yira Namachika Director of Water Quality (714) 378-3281

Response: Please see response to comment codes 37000 Viruses and 38100 Chromium-6.
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Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31872

Comment Code: 38200

Comment: Page 11718: "EPA requests comments on what contaminant(s) should be removed from 

the list of 30 UCMR 3 contaminants if chromium-6 were added, as well as comments regarding the 

recommended and alternative analytical method(s) and the appropriate reporting level. EPA also 

requests comments on whether total chromium should also be measured concurrent with 

chromium-6."

If chromium-6 is added, it should be measured concurrent with total chromium. The relationship 

between the valence states of chromium within the drinking water system is one of the complexities 

of chromium regulation. In order to adequately quantify the relationship and support development 

of a future rule, if needed, both hexavalent chromium and total chromium should be measured 

under the same monitoring scheme in UCMR3. In adding these contaminants, EPA needs to 

consider the current science regarding changes in chromium through the treatment plant and 

distribution system to establish a monitoring plan that maximizes the value of the data for 

developing any future regulation. 

Response: Many of the issues raised in this comment are more appropriately addressed if and when 

any future regulatory determinations are made concerning chromium regulations. EPA agrees that 

there are limitations on the research related questions that can addressed in UCMR. However, the 

occurrence data in both EPTDS and DSMRT will provide EPA with a valuable dataset that will 

support the determination of possible regulatory actions. 

Please see response to comment code 38100 Chromium-6.

Commenter Name: Darrell Osterhoudt 

Commenter Organization: ASDWA

Letter ID: 0066

Comment ID: 31873

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: If hexavalent chromium and total chromium, or any of the other recommended 

contaminants were added to UCMR 3, some contaminants would have to be deleted. We are not 

recommending the deletion of specific contaminants on a one to one basis but instead recommend a 

list of lower priority contaminants for EPA to consider eliminating. It’s not that that data on these 

contaminants would not be useful, but we believe they are of less value than others on the list. This

is either because states feel the contaminants will not be found at significant levels or data on their 

occurrence will not add to information gained through monitoring related contaminants that remain 

on the list. 

Response: Please see response to comment code 38100 Chromium-6.
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Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31887

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: The NJDEP also supports including hexavalent chromium on the UCMR3 list of 

contaminants for nationwide monitoring, as this contaminant has been detected in various media in 

New Jersey and in water supplies throughout the country. This monitoring should also include total 

chromium in order to further understand the relationship between the occurrence of total chromium 

and hexavalent chromium. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31894

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: 7.0 Chromium-6 and Total Chromium 

EPA is requesting comments on whether to include hexavalent chromium (chromium-6) as one of 

the 30 contaminants proposed for UCMR3 for Assessment Monitoring (FR page11718). EPA is also 

requesting comments on whether to include testing for total chromium concurrently with 

chromium-6. Collecting occurrence data for both chromium-6 and total chromium would provide 

information to assess if total chromium could be a viable surrogate for chromium-6. EPA is also

requesting comment on the analytical method and appropriate reporting level. 

7.1 Chromium-6 and Total Chromium: Inclusion in UCMR3 

Chromium-6 has been a contaminant of interest in CA for over a decade. In 1999, the CA 

Department of Public Health (CDPH, formerly CA Department of Health Services (CDHS)) 

indentified chromium-6 to be included in the CA’s unregulated chemicals requiring monitoring 

(UCMR). CA required analysis for chromium-6 using EPA Method 218.6 at a detection limit for 

reporting purposes (DLR) of 1 ug/L. Monitoring for chromium-6 occurred between January 1, 2001 

and December 31, 2002. CA will be developing a drinking water standard (i.e., MCL) for chromium6 once the CA Office of Environmental Health Hazard and Assessment (OEHHA) finalizes the CA

Public Health Goal (PHG). 

The primary purpose of the USEPA Contaminant Candidate List (CCL) and the UCMR program is 

to provide information for EPA to determine which drinking water contaminants have the highest 

potential to provide a meaningful opportunity to reduce health risk by establishing a primary 
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drinking water regulation. The CCL process identifies contaminants that are anticipated to occur in 

drinking water while the UCMR program provides national occurrence information for EPA to 

determine if a contaminant occurs at a frequency and concentration that would be a public health 

concern. Currently, total chromium is an inorganic contaminant that is regulated with a primary 

drinking water standard and includes both chromium-6 and chromium-3. There is no primary 

drinking water standard for chromium-6 at the federal level or in California at this time.

Including regulated contaminants in the UCMR list is not the intended purpose of the program and 

in general ACWA would not support the inclusion of regulated contaminants in the UCMR 

program. However, ACWA is aware of the enhanced public awareness surrounding chromium-6 

exposure at lower levels than what is currently regulated and does not disagree that additional steps 

should be taken to determine if it is a risk to the public. In fact, we wrote a letter in response to 

EPA’s January 2011 "Guidance for Public Water Systems on Enhanced Monitoring for Chromium-6 

(Hexavalent Chromium) in Drinking Water," outlining California’s efforts to address chromium-6, 

the importance of appropriate and thorough occurrence data to the establishment of a drinking 

water standard, and the relationship between total chromium and chromium-6 monitoring. As a 

result, ACWA would be willing to support the inclusion of total chromium and chromium-6 as a

one-time exception in order to expedite the collection of source and occurrence information of 

chromium-6 data. With this preface, ACWA recommends that EPA include both chromium-6 and 

total chromium in the UCMR3 nationwide Assessment Monitoring (List 1).

ACWA supports monitoring for chromium-6 and total chromium at the EPTDS and DSMRT 

locations to provide EPA with occurrence data to evaluate if chromium-3 is oxidized to chromium-6 

in the presence of an oxidant (e.g., chlorine, ozone, etc.) and to assess the feasibility of using total 

chromium as a monitoring surrogate for chromium-6 (less costly analysis and avoids the short 

holding time required for chromium-6 analysis).

In the interim of release of the final National Toxicity Program (NTP) report, including chromium-6 

and total chromium in the UMCR3 program will be timely to provide occurrence information that 

will be needed in the MCL setting process. Monitoring during the 2013-2015 period will avoid delays 

to secure nationwide occurrence data if a regulatory determination to establish an MCL for 

chromium-6 is needed based on the final NTP report on the human health assessment and exposure 

to chromium-6.

We also encourage EPA to review and utilize the existing database for total chromium to determine 

if it can provide useful occurrence data. While we do support the inclusion of total chromium and 

chromium-6 in UCMR3 as a one-time exception, ACWA believes that reviewing monitoring data 

already collected would also assist EPA in its efforts.

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31897

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 37000 Viruses; 38100 Chromium-6 
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Comment: *Information gained from the limited, narrow virus focus by monitoring select 800 

small systems using undisinfected groundwater will not provide meaningful data to benefit and 

support the overall UCMR goals to provide information for future regulatory decision-making in 

contrast to the benefits potentially gained by including chromium-6 and total chromium in UCMR3. 

The value gained by testing for chromium-6 and total chromium provides national occurrence 

information that will be meaningful for EPA to determine if regulation may be warranted and far

outweighs the data gathering information for Pre-Screening testing for viruses. 

ACWA appreciates the opportunity to review and comment on the proposed UCMR3 program. If 

you have questions or need further information, please contact me at 916- 441-4545 or ACWA’s 

UCMR3 Workgroup Chair, Nira Yamachika with Orange County Water District, at 714-378-3200.

Sincerely,

Danielle Blacet Senior Regulatory Advocate 

Response: EPA believes that virus monitoring under UCMR 3 will be useful because there are a 

large number of small systems serving untreated water but there is very little information regarding 

virus occurrence in these systems.

EPA will monitor for enteroviruses and noroviruses under UCMR 3 as Pre-Screen Testing. PreScreen Testing is designed to address contaminants with analytical methods that are in an early stage 

of development for use at a limited number of systems determined to be most vulnerable to the 

targeted contaminants.

Please see response to comment codes 37000 Viruses and 38100 Chromium-6.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31916

Comment Code: 38200

Comment: If hexavalent chromium is monitored as part of the UCMR3, total chromium should 

also be measured in the same samples. Although total chromium cannot be used as a surrogate for 

hexavalent chromium, information on total chromium along with hexavalent chromium may 

provide valuable information on the relationship between the different forms of chromium in 

drinking water. 

Response: Please see response to comment code 38100 Chromium-6.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32063
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Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: Total Chromium - While a dataset based on the UCMR3 data collection protocol will be 

central to characterizing national occurrence of Cr-6, it will not answer all of the questions relevant 

to a regulatory decision-making process. Ancillary databases will need to be developed that:

1. Provide a basis to determine what fraction of total chromium is present as Cr-6 in treated water 

and in water once it has been distributed; 

2. Characterize the relative contributions of the various sources of Cr- 6 (e.g., source water as Cr-6, 

source water Cr-3 that is converted to Cr-6 in treatment, Cr-3 and Cr-6 that is introduced to 

drinking water through treatment chemicals and materials, etc.); and

3. Inform developing appropriate treatment options to reduce Cr-6 exposure. 

The question of what fraction of Cr-6 is present as total chromium is very relevant to EPA decisionmaking as the current total chromium MCL is based on health risk associated with Cr-6. Future 

EPA regulatory decisions regarding Cr- 6 must address whether management of total chromium is 

an appropriate strategy to manage Cr-6 or not. Information to describe the relationship between 

total chromium, treatment, and Cr-6 reaching the customer is very important, sufficiently so that it is 

best developed in a way that allows detailed evaluation of the data generated, rather than the

UCMR3 framework.

Response: Many of the issues raised in this comment are more appropriately addressed if and when 

any future regulatory determinations are made concerning chromium regulations. EPA agrees that 

there are limitations on the research related questions that can addressed in UCMR. However, the 

occurrence data in both EPTDS and DSMRT will provide EPA with a valuable dataset that is 

essential to the determination of possible regulatory actions. 

Please see response to comment code 38100 Chromium-6. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32073

Comment Code: 38200

Other EPA Comment Codes and Descriptions: 38100 Chromium-6 

Comment: Should total chromium be measured concurrently with Cr-6? -- Information to describe 

the relationship between total chromium, treatment, and Cr-6 reaching the customer is very 

important, sufficiently so that it is best developed in a way that allows detailed evaluation of the data

generated. Based on past experience, focused research projects rather than the UCMR monitoring 

framework likely provide a better opportunity for discerning this relationship and its impact on risk 

management options. 

Response: Please see response to comment code 38100 Chromium-6.
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38210 EPA Method 200.8 Rev 5.4 - Total Chromium Page 352 of 401

Comment Code: 38210 EPA Method 200.8 Rev 5.4 - Total Chromium

Summary Response to Comments on EPA Method 200.8 Rev 5.4 - Total Chromium: EPA is 

using the authority provided in SDWA Section 1445(a)(1)(A), not the UCMR authority, to require 

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

Since all of the UCMR 3 samples are finished drinking water, EPA does not agree that false positives 

and/or false negatives will result from the analysis of drinking water using 200.8 without the use of a 

collision cell because of the low concentration of potential interfering compounds. In addition, an 

adequate analytical method incorporating collision cells is not currently available. EPA is conducting 

research into such a method, but it was not available when the UCMR 3 final rule was developed.

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 NPDWRs 

(USEPA, 2010) 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: (1) generating national occurrence data in UCMR 3 will avoid potential delays 

in any possible regulatory action; and, (2) 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. 

EPA agrees with commenters that there are advantages to measuring both total chromium and 

chromium-6 using the same MRLs. However, analytical methodology does not provide us with a 

method for the determination of total chromium at the same levels as those achievable for 

chromium-6 monitoring. Analysis of chromium-6 at lower concentrations will provide valuable data 

on its occurrence and the possible health implications of occurrence at those lower concentrations. 

EPA agrees with the use of a multi-laboratory study to set the MRL for total chromium monitoring. 

That study has been completed and the results used to set the MRL for total chromium. 

Please see response to comment code 38210 EPA Method 200.8 Rev 5.4 - Total Chromium. 

USEPA. 2010. 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_review/upl

oad/6Yr2OccurrenceReport_Revised_September2010.pdf. 

Individual Comments
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38210 EPA Method 200.8 Rev 5.4 - Total Chromium Page 353 of 401

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31754

Comment Code: 38210

Comment: 17. We do not support the inclusion of total chromium measurements in the UCMR3 

program. It is not clear whether the EPA has the authority to implement additional monitoring of a 

currently regulated analyte under the UCMR program. Even more important, there has been limited 

work done on the reliability of EPA method 200.8 for total chromium at ppb or sub-ppb levels. 

There is ample data in the literature showing potential issues with either false positives or false 

negatives for total chromium at the ppb level without using special technologies such as collision cell 

ICPMS with method 200.8, which EPA has stated is not currently permitted under the Safe 

Drinking Water Act. If EPA does elect to include total chromium, EPA must conduct an LCMRL 

determination for total chromium by this method using samples that contained appropriate potential 

interferences such as high alkalinity (rather than DI water).

Response: Please see response to comment code 38210 EPA Method 200.8 Rev 5.4 - Total 

Chromium. 

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32064

Comment Code: 38210

Comment: To collect data to inform these questions, the current total chromium method will need 

to be revised and improved. At present, the method is not reliable at levels below 1 ppb, due to 

potential carbon-based interferences (e.g., ArC+) that are not reliably corrected by inter-element 

correction factors at sub ppb concentrations of chromium. Additionally, there have been questions 

on the reliability of sample preparation methods for total chromium. This interference is occurring 

well above the potential DWEL for Cr-6, and consequently, impedes analysis regarding conversion 

of Cr-3 to Cr-6 (again, assuming the DWEL for Cr- 6 is at nanogram per liter level). While there is 

literature describing methods for measuring total chromium at concentrations of 0.2 ppb or lower, 

those methods have not been subjected to rigorous inter-laboratory comparisons or been subjected 

to EPA’s Lowest Concentration Minimum Reporting Level (LCMRL) determination protocols. 

Additionally, EPA has not validated EPA Method 200.8, the presumed default method for total 

chromium, at the low levels that will occur in many systems. If the total chromium MRL is 

substantially above the MRL for Cr-6, and there are significant numbers of Cr-6 detects below the 

total chromium MRL, it will make data interpretation more difficult. 

Response: Please see response to comment code 38210 EPA Method 200.8 Rev 5.4 - Total 

Chromium. 

Commenter Name: Thomas W. Curtis
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January 2012

38210 EPA Method 200.8 Rev 5.4 - Total Chromium Page 354 of 401

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32072

Comment Code: 38210

Comment: Analytical Methods for Total Chromium -- The current total chromium method will 

need to be revised and improved. At present, the method is not reliable at levels below 1 ppb, due to 

potential carbon-based interferences (e.g., ArC+) that are not reliably corrected by inter-element 

correction factors at sub ppb concentrations of chromium. Additionally, there have been questions 

on the reliability of sample preparation methods for total chromium. This interference is occurring 

well above the potential DWEL for Cr-6, and consequently, impedes analysis regarding conversion 

of Cr-3 to Cr-6 (again, assuming the DWEL for Cr- 6 is at nanogram per liter level). While there is 

literature describing methods for measuring total chromium at concentrations of 0.2 ppb or lower, 

those methods have not been subjected to rigorous inter-laboratory comparisons or been subjected 

to EPA’s Lowest Concentration Minimum Reporting Level (LCMRL) determination protocols. 

EPA has not validated EPA Method 200.8, the presumed default method for total chromium, at the 

low levels that will occur in many systems. If the total chromium MRL is substantially above the 

MRL for Cr-6, and there are significant numbers of Cr-6 detects below the total chromium MRL, it 

will make data interpretation more difficult. 

Response: Please see response to comment code 38210 EPA Method 200.8 Rev 5.4 - Total 

Chromium. 
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January 2012

38250 Sampling Location - Total Chromium Page 355 of 401

Comment Code: 38250 Sampling Location - Total Chromium

Individual Comments

Commenter Name: Kevin S. Milligan

Commenter Organization: City of Riverside Public Utilities

Letter ID: 0089

Comment ID: 31838

Comment Code: 38250

Other EPA Comment Codes and Descriptions: 38130 Sampling Location - Chromium-6 

Comment: Riverside also supports monitoring for chromium-6 and total chromium at the EPTDS 

and DSMRT locations to provide EPA with occurrence data to evaluate if chromium-3 is oxidized 

to chromium-6 in the presence of an oxidant (e.g., chlorine, ozone, etc.) and to assess the feasibility 

of using total chromium as a monitoring surrogate for chromium-6 (less costly analysis and avoids 

the short holding time required for chromium-6 analysis).

Response: Please see response to comment code 38130 Sampling Location - Chromium-6.
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January 2012

40000 Minimum Reporting Level Determination/LCMRLs Page 356 of 401

Comment Code: 40000 Minimum Reporting Level Determination/LCMRLs

Summary Response to Comments on Minimum Reporting Level Determination/LCMRLs: 

Regarding public comments on the complexity of the Lowest Concentration Minimum Reporting 

Level (LCMRL) and the Minimum Reporting Level (MRL) procedures, EPA notes that laboratories 

that participate in UCMR 3 do not need to use the LCMRL and MRL procedures, although 

laboratories are encouraged to determine their own LCMRLs if so desired. The LCMRL calculator 

tool is available for download on EPA's website for this purpose at: 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. Laboratories 

that participate in UCMR 3 will be required to demonstrate their ability to meet the UCMR 3 analyte 

MRLs in their IDC as part of the UCMR 3 Laboratory approval process, as described in EPA's 

UCMR 3 Laboratory Approval Requirements and Information Document. In addition, laboratories 

that participate in UCMR 3 will be required to run a daily check sample (i.e., a Continuing 

Calibration Check - CCC) for each analyte, fortified at or below each UCMR 3 MRL, and 

demonstrate recovery of ±50%. The calculations and procedures for both of these requirements are 

no more complex than those that comprise a Method Detection Limit (MDL) study. 

The LCMRL/MRL procedures produce statistically robust reporting levels (i.e., the UCMR 3 

MRLs). For UCMR 3 to produce data of greatest value in the protection of public health, 

laboratories need a clear but robust framework to ensure that occurrence data are available from 

technically-proficient laboratories, and that the data are generated as close to or below levels of 

concern for human health protection as possible. These data also require quality characteristics that 

support their potential use for EPA decision-making.

While the technical basis of the LCMRL/MRL procedures is statistically complex, it is based on a 

sound theoretical model. The LCMRL procedure is easily conducted using a user-friendly LCMRL 

calculator tool, if laboratories choose to determine their internal LCMRLs. To re-iterate, laboratories 

are not required to use the LCMRL/MRL determination procedures as part of UCMR 3; laboratory 

requirements are limited to the demonstration of meeting MRLs as part of IDC and to the analysis 

of CCC standards as outlined in EPA's UCMR 3 Lab Approval Manual. 

Regarding public comments on the LCMRL and MRL procedure and a perceived lack of 

transparency, complex statistical terms, and a lack of peer review, the technical basis for the 

determination of LCMRLs and MRLs is available for download on EPA's website at: 

http://water.epa.gov/scitech/drinkingwater/labcert/analyticalmethods_ogwdw.cfm. A draft of this 

document was sent for expert review by EPA in 2008. Six experts in the fields of analytical 

chemistry and/or statistics reviewed the technical basis of the LCMRL and the LCMRL calculator 

tool, including three experts from the United States Geological Survey's (USGS) National Water 

Quality Laboratory (NWQL)/Branch of Quality Systems, an expert from EPA's National Exposure 

Research Laboratory (NERL), an expert at Lockheed Martin Information Technology, and an expert 

from the Environmental Forensic and Analytical Science Department of Environment and Climate 

Change of Australia. 

In addition to the 2008 expert review, the entire conceptual framework of the LCMRL/MRL 

concept was sent for expert review in 2003 as part of its development for UCMR 2. At that time, 

five experts in the fields of analytical chemistry and/or statistics reviewed the framework and 
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40000 Minimum Reporting Level Determination/LCMRLs Page 357 of 401

technical basis for the LCMRL/MRL process as it was originally developed for UCMR 2. These 

experts included an expert from USGS' NWQL, an expert retired from the United States Food and 

Drug Administration, and expert from a large national drinking water laboratory, an expert from the 

Association of Analytical Chemists (AOAC International), and an expert from the Engineering and 

Analysis Division of EPA's Office of Science and Technology (OST). Thus, the initial framework 

and statistical basis of the procedures have been extensively reviewed and both the initial 

LCMRL/MRL procedures and revised LCMRL/MRL procedures were presented to the public at 

UCMR Stakeholder meetings held in 2003 and 2010 for UCMR 2 and UCMR 3, respectively. The 

only substantive changes between the LCMRL/MRL procedures used for UCMR 2 and those used 

for UCMR 3 involve replacement of the Ordinary Least Squares graphical approach to determining 

the LCMRL and the mean + 3 standard deviations approach to determining the MRL with a more 

sophisticated and robust regression procedure for determining the LCMRL and a Bayesian 

Bootstrap procedure to more reliably represent natural laboratory variability in the determination of 

the MRL while maintaining the same Data Quality Objectives needed to generate occurrence data of 

sufficient quality to support potential EPA decision making. As described above, the required use of 

the LCMRL procedure is limited to laboratories that assist EPA with LCMRL studies as part of 

UCMR development and the LCMRL calculator tool greatly facilitates the determination of 

LCMRLs. The MRL procedure is employed only by EPA to establish uniform, performance-based 

reporting levels for use in UCMR. 

Regarding public comments on laboratory selection for LCMRL determination and laboratory 

capacity, EPA does not select only the most experienced laboratories to provide LCMRL data for 

the determination of MRLs for the UCMR program. EPA strives to include a diverse selection of 

laboratories for the LCMRL studies that have been conducted. A recent LCMRL study that included 

digestion of the five metals listed in UCMR 3 included laboratories of varying size, experience, and 

business status.

EPA believes that the laboratories that were selected to perform the LCMRL studies are 

representative of national laboratory performance. The process for determining MRLs and 

approving laboratories for UCMR 3 - selecting laboratories for LCMRL studies, determining MRLs, 

and approving laboratories for participation in UCMR 3 - is fundamentally the same as it was for 

UCMR 2. Approximately 50 laboratories were approved for participation in UCMR 2 and EPA 

anticipates that an appropriate number of laboratories will be approved for UCMR 3. 

Regarding public comments on the lack of a means for addressing false positives at or near the 

MRL, the revised field blank requirements outlined in the final rule are designed to address this 

issue. Further guidance on field blank requirements will be included in the final UCMR 3 Lab 

Approval Manual. 

With regard to comments that the MRLs are being set well below HRLs in certain cases and further, 

that dilution issues could result (e.g., for strontium), it should be noted that new health effects data 

may become available in the future that result in lower HRLs. Therefore, since the HRLs are not 

fixed, but rather a value that varies based on new studies or revised evaluation procedures, EPA has 

determined that it is prudent to base UCMR MRLs on a scientifically sound determination of 

laboratory capabilities, rather than a potentially transient HRL value. Basing the MRLs solely on the 

current HRL values, when lower MRLs are analytically achievable without excessive cost differences, 

would not be the best use of the limited resources available for water systems and laboratories that 

participate in unregulated contaminant monitoring. EPA agrees that, for a contaminant such as 

strontium, previously-collected data does suggest that this contaminant is likely to be seen in a large 
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percentage of the samples and at concentrations that may be considerably higher than the MRL. 

However, strontium is being analyzed in the same samples as several other metals that may require 

analysis in undiluted samples. Therefore, EPA believes that it is worthwhile to collect the data on 

low concentration occurrence of strontium since that analysis is already being performed for other 

metals.

Individual Comments

Commenter Name: Therese M. Cirone

Commenter Organization: The Chlorine Institute 

Letter ID: 0053

Comment ID: 31626

Comment Code: 40000

Other EPA Comment Codes and Descriptions: 35100 Chlorate

Comment: Chlorate Monitoring - MRL 20 ug/l

EPA is proposing that the MRL for chlorate be 20ug/l. Given that chlorates have not been found to 

be carcinogenic, mutagenic or genotoxic and no reproductive or developmental toxicity has been 

observed in studies, it would appear this MRL is artificially set by at least an order of magnitude 

below its potential health risk level. The Chlorine Institute is concerned that this could potentially

generate data that may be subject to misinterpretation because of a notion that any positive values 

are potentially considered significant. Given that the purpose of UCMR monitoring is to determine 

the occurrence in the range of concentrations relevant to public health protection, EPA should set 

appropriate minimum reporting levels that reflect the level of potential health relevance.

The Chlorine Institute strongly supports EPA’s efforts to continually improve drinking water 

programs and to protect the public health. We thank EPA for this opportunity to provide input and 

ask that our comments be considered in development of the final rule. 

Sincerely, Therese M Cirone Vice President Health, Environment, Safety and Security

Response: Please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Stephen Estes-Smargiassi

Commenter Organization: Massachusetts Water Resources Authority

Letter ID: 0062

Comment ID: 31661

Comment Code: 40000

Comment: Laboratory Methods and Reporting Limits 

The AWWA and AMWA staff and volunteers have compiled a comprehensive set of comments on 

these topics. MWRA has participated in their development and agrees with them. It is critical that 

the methods be robust and consistent, that the reporting limits support the intent of the UCMR, and 

that false positives or false precision not undermine the value of all the effort which will be 
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expended to comply with this rule. While we have not repeated those comments here, we urge EPA 

to give careful consideration to each and every comment provided by AWWA and AMWA on this 

topic. 

Thank you for the opportunity to comment on these important regulations. If we can provide EPA 

any additional data on any of these topics, please feel free to contact me at 617-788-4303 or 

(smargias@mwra.state.ma.us).

Very Truly Yours, Stephen Estes-Smargiassi Director of Planning 

Response: Please see response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs and responses to comment IDs 31776, 32087, and 32106 and under 

comment code 40000. 

Commenter Name: Margaret Ryan

Commenter Organization: New Mexico Environment Department (NMED)

Letter ID: 0072

Comment ID: 31687

Comment Code: 40000

Comment: Page 11720

EPA requests comments regarding the proposed definition of the MRL. 

NMED Comment

Express the minimum reporting level in terms of the lowest concentration minimum reporting level 

as defined in EPA 815R11001, the Technical Basis for the Lowest Concentration Minimum 

Reporting Level, LCMRL, Calculator.

NMED Contacts

Margaret Ryan, Chief New Mexico Environment Department Drinking Water Bureau 525 Camino 

de los Marquez, Suite 4 Santa Fe, NM 87505 505.476.8641 voice 505.476.8656 fa

XAngela Faye Cross, P.E., Staff Engineer New Mexico Environment Department Drinking Water 

Bureau 1052 Main Street, NE, Suite C Los Lunas, NM 87031 505.841.5376 voice 505.841.5284 fax

Response: The MRL is defined in Appendix A of the document cited in this comment. The MRL is 

taken to be the upper 95% one-sided confidence interval on the 75th percentile of the predicted 

distribution. The distribution from which the MRL is taken is generated from raw LCMRL data 

from at least three laboratories that participated in EPA LCMRL studies for the UCMR 3 analytes. 

The raw LCMRL data are weighted and iterated approximately 200 times (the Bayesian Bootstrap 

procedure) to produce multiple estimates of each laboratory's LCMRL. Thus, the MRL cannot be 

defined in terms of an LCMRL value or even multiple LCMRL values from specific laboratories. 

Rather, the MRL is defined in terms of a theoretical distribution of LCMRL values that are 

generated from a practical number of laboratory-specific measurements during an LCMRL study. 
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Commenter Name: Steve Bigley

Commenter Organization: Coachella Valley Water District (CVWD)

Letter ID: 0090

Comment ID: 31724

Comment Code: 40000

Comment: 7. Lowest Concentration Minimum Reporting Level (LCMRL). EPA proposes to 

implement a new method to determine the Minimum Reporting Level (MRL) for monitoring 

performed under UCMR3. The new method utilizes multiple statistical models in a complex 

multiple step process that is extremely computational intensive. The process is so complex that it is 

anticipated that laboratory staff will use a pre-programmed calculator that manipulates the data to 

generate the LCMRL. With few analysts expected to fully understand how the LCMRL is produced, 

it is not clear how laboratory staff will be able to use this process to produce better data for UCMR3 

monitoring. Supporting information in the draft UCMR3 fails to adequately justify the proposed 

complex process for generating the LCMRL and lacks a comparative assessment of different 

methods available to validate the quality of laboratory MRLs. CVWD recommends EPA consider a 

simpler more transparent process like that recommended by the Federal Advisory Committee on 

Detection and Quantification, which is based on providing known concentrations of a parameter to 

study laboratories and empirically determining the lowest level of the target analyte that the 

laboratories can accurately measure. This approach can be used to determine if laboratories can 

achieve a measurement quality objective but in a transparent manner that is easily understood and 

accessible to interested parties.

If you have any questions, please call me at extension 2286.

Yours very truly,

Steve Bigley Environmental Services Manager

MM:ch\eng\wr\I i \MAY\Contaminant Monitoring Regulation 

Response: Please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31740

Comment Code: 40000

Comment: April 25, 2011 Water Docket United States Environmental Protection Agency Mail 

Code 282211T 1200 Pennsylvania Avenue, N.W. Washington, DC 20460 Attention: Revisions to 

the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems, Docket 

ID No. OW-2009-0090
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Dear Sir or Madam:

Thank you for the opportunity to comment on the subject of the proposed regulation. MWH Labs, 

a Division of MWH Americas, Inc. is the nation’s largest commercial drinking water laboratory and 

has been involved extensively with the UCMR process for a variety of utilities since 2001. We served 

as an EPA contractor for small systems monitoring during UCMR1 and UCMR2 as well as provided 

testing for more than 250 large utilities during UCMR2. We also assisted EPA in performing 

LCMRL verification determinations for several of the UCMR3 methodologies by serving as an 

external lab. Our experience with prior UCMRs and recent LCMRL experience provides the 

framework for our responses to various questions posed by EPA and other issues. Our comments 

focus on several items that we regard as critical.

1. While we find the LCMRL protocol to be robust and a positive change from the historical use of 

multipliers of MDLs for establishing MRLs, we remain concerned about some of the specific 

LCMRLs and proposed MRLs. 

a. The labs that were used to determine initial LCMRLs for each of the proposed methods were all 

very experienced labs, and therefore even though a bootstrap protocol was used to model the 

system and nominally make it more conservative, we believe that the dataset used is not 

representative of all the labs that might be expected to participate in the UCMR3.

b. For the metals the protocol described in the UCMR proposal and lab approval manual requires 

that samples be digested prior to analysis, even if the turbidity is <1 NTU. When the LCMRL 

determinations for metals were performed on behalf of EPA this was not one of the requirements 

and the samples were not necessarily digested. Thus the LCMRLs may be unduly low.

c. Additionally for the metals our instructions as one of the participating laboratories were to not be 

concerned about going below 1 ug/L for any of the metals, but the final MRLs for both vanadium 

and strontium are both in the sub- ug/L level. It is not clear what Page 2 of 7 data set was used as 

the basis for these MRL determinations. 

d. The protocol used to establish an MRL from the subset of LCMRL data is on an analyte by 

analyte basis. However samples are run by METHOD, rather than by analyte. A given lab may have 

very different relative sensitivities for different analytes in a given method, which may be different 

among labs. From review of LCMRL data from two participating external labs for method 539 in

addition to the published LCMRL data in the method, we noted several cases where two labs could 

have opposite results for different analytes in the same method. An individual lab could be very low 

(by at least an order of magnitude) on one analyte relative to others and very high (by an order of 

magnitude) on another analyte. We believe that EPA needs to explain how the multilab MRL 

determination takes METHOD variability (and not just single analytes) into account. 

e. LCMRL determinations are made on reagent water (as were the old MDL determinations). For 

newer methods like LC-MS-MS where there can be significant matrix enhancement or suppression it 

would seem more appropriate to do LCMRL determinations for a "national MRL" on drinking 

water matrices, rather than assuming that the LCMRL for reagent water will be representative of all

matrices.
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Response: Regarding your comments on the types of laboratories used for LCMRL studies and 

sample digestion, please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Regarding your comments on spiking levels for the LCMRL studies for metals, the LCMRL study 

for the UCMR 3 metals was repeated to include sample digestion and spikes in the sub-μg/L region 

were common.

Regarding the comments on method vs. analyte sensitivity, while analytes may be aggregated into a 

single analytical method, the sensitivity of each individual analyte will vary widely within that 

method. The potential for variable sensitivities from analyte to analyte and from laboratory to 

laboratory is captured by the various laboratories that participate in the LCMRL studies. The 

Bayesian bootstrapping procedure is designed to take into account this potential interlaboratory 

variability as part of the calculation of MRLs.

Regarding your comments on matrix effects, matrix effects are evaluated as part of method 

development, which is distinct from individual laboratory LCMRL determinations and MRL 

determinations. The LCMRLs and MRLs are more closely associated with method QA/QC 

procedures, which are also carried out in reagent water. Thus, EPA believes that use of reagent 

water is appropriate for LCMRL/MRL determinations.

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31742

Comment Code: 40000

Comment: g. EPA should provide tables of the LCMRL data that was used to generate the UCMR3 

MRLs to provide more transparency to the process. 

2. Given that the purpose of UCMR monitoring is to establish national occurrence data relative to 

potential regulatory levels established from Health Reference Levels (HRLs), the MRLs should 

preferably be established as a fraction of the HRL (ideally 1/10 of the HRL, if the method is capable 

of achieving that level), rather than solely from analytical capabilities. EPA does not appear to have

been completely consistent in this matter. 

a. For chlorate, EPA recognized that 10-20 ug/L would be more than adequate as an MRL 

considering the 200 ug/L HRL, and the likelihood of chlorate occurrence. Our LCMRL instructions 

for chlorate were to not calibrate below 10 ug/L, even though we have previously demonstrated the 

ability to measure far below that level.

b. For strontium, the MRL was established based on analytical capabilities at 0.3 ug/L, with an HRL 

level of 4,200 ug/L. Our experience analyzing samples from all across the U.S. for strontium is that 

the majority of samples have detectable strontium above a reporting level of 10 ug/L, with 

concentrations ranging as high as 1 to 2 ppm. This means that (a) labs testing for strontium in 
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UCMR3 will likely be doing a large number of reruns for dilutions and (b) the MRL is not relevant 

to either the occurrence level or the HRL. 

Response: Regarding your comments on LCMRL study data, EPA has provided a list of singlelaboratory LCMRLs in the UCMR 3 docket.

Regarding your comments on setting the MRLs as a fraction of HRLs, please see the response to 

comment code 40000 Minimum Reporting Level Determination/LCMRLs. 

Regarding your comments on calibration for the chlorate LCMRL study, the MRL for chlorate in 

UCMR 3 is 20 μg/L, so calibration down to 10 μg/L should be sufficient. 

Regarding your comments on the strontium MRL, please see the response to comment code 40000 

Minimum Reporting Level Determination/LCMRLs. 

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31743

Comment Code: 40000

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: 3. We are concerned that with the low MRLs proposed for method 539, some non 

CCL3 analytes (e.g. testosterone) are low enough (0.0001 ug/L) to anticipate a potential for 

inadvertent field contamination or lab contamination. At present there is no provision in either 

method 539 or UCMR3 for a field blank on this method (and subsequent guidance on how to use 

the field blank to qualify/disqualify actual sample results). With the extremely low MRL and the

requirement that lab blanks be <1/3 of the MRL it is possible that labs will upon occasion have 

difficulty meeting this requirement, or there will be results that may be questionable as a result of 

field contamination, resulting in potential needs for resamples by utilities. The repercussion may be 

that prices for method 539 may be elevated (to account for the need for re-extractions) compared to 

where they would be with a more realistic MRL. Additionally, at these low MRLs, the desirability for 

a field blank would also increase costs (even more directly) for utilities.

Response: Please see response to comment code 31010 EPA Method 539 - Hormones. 

Commenter Name: Andrew Eaton

Commenter Organization: MWH Laboratories

Letter ID: 0047

Comment ID: 31749

Comment Code: 40000

Comment: 12. The choice of analytes for UCMR3 is a policy issue rather than a strictly scientific 

issue. We do feel that setting MRLs for non CCL3 analytes (such as some of the hormones and 

PFCs) based solely on analytical capabilities is inappropriate because of the LCMRL and potential 

blank issues raised above. It would perhaps be more appropriate to set the MRLs for those analytes 
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equal to the highest of the CCL3 analytes in the same method (assuming that the LCMRL 

determinations support meeting that limit). Testosterone, for example, would be set at 0.004 ug/L 

rather than 0.0001 ug/L.

Response: Given the new requirements for field blanks and because HRLs can change in the future 

if new toxicological data become available, EPA believes that setting the MRLs based on analytical 

capability is the most appropriate approach for UCMR 3. 

Commenter Name: Ralph Schulz 

Commenter Organization: EDP Laboratory, Georgia Department of Natural Resources

Letter ID: 0049

Comment ID: 31759

Comment Code: 40000

Comment: Having performed UCMR-1 and UCMR-2 I would ask that the Quality Control 

objectives allow for a recovery above method limits in the opening Initial Calibration Verification 

and the final Closing Calibration Verification of a sequence if no UCMR-3 target compounds are 

detected in any field samples run in the sequence. The instrument has been shown to be "Bias High" 

but with no detects in the field samples the data should be considered valid. However if the 

Fortified Field Sample is run the initial CCV must pass. A "Bias High" surrogate recovery in a field 

sample should also be allowed if there are no detects in the field sample and the data should be 

valid. If a Fortified Field Sample is to reflect true recovery values obtained in the analysis then any 

failures should be accepted and not questioned, especially if LFB data is valid and within QC 

objectives to support a valid extraction. Fortified Field Samples, even drinking water samples used 

for UCMR are not Pure Filtered Laboratory Water Samples and react in an unexpected manner. 

Recovery failures with these Fortified Field Samples happen and must be accepted if the LFB is 

valid.

Response: These issues are addressed in the revised UCMR 3 Laboratory Approval Requirements 

and Information Document. 

Commenter Name: Robert A. Hollander 

Commenter Organization: Western Coalition of Arid States (WESTCAS)

Letter ID: 0058

Comment ID: 31766

Comment Code: 40000

Comment: 7. Lowest Concentration Minimum Reporting Level (LCMRL). EPA proposes to 

implement a new method to determine the Minimum Reporting Level (MRL) for monitoring 

performed under UCMR3. The new method utilizes multiple statistical models in a complex 

multiple step process that is extremely computational intensive. The process is so complex that it is 

anticipated that laboratory staff will use a pre-programmed calculator that manipulates the data to 

generate the LCMRL. With few analysts expected to fully understand how the LCMRL is produced, 

it is not clear how laboratory staff will be able to use this process to produce better data for UCMR3 

monitoring. Supporting information in the draft UCMR3 fails to adequately justify the proposed 

complex process for generating the LCMRL and lacks a comparative assessment of different 
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methods available to validate the quality of laboratory MRLs. WESTCAS recommends EPA 

consider a simpler more transparent process like that recommended by the Federal Advisory 

Committee on Detection and Quantification, which is based on providing known concentrations of 

a parameter to study laboratories and empirically determining the lowest level of the target analyte 

that the laboratories can accurately measure. This approach can be used to determine if laboratories 

can achieve a measurement quality objective but in a transparent manner that is easily understood 

and accessible to interested parties.

WESTCAS appreciates the opportunity to review this proposal and your consideration of these 

comments.

Respectfully submitted, Robert A. Hollander President, WESTCAS

Response: Please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31776

Comment Code: 40000

Comment: 10. Analytical methods

AMWA has three specific comments regarding the proposed analytical methods and one comment 

related to sample collection.

First, these methods are very specialized and expensive. EPA must ensure sufficient laboratory 

capacity as most large utilities will send their samples to outside labs rather than upgrade their 

laboratory equipment and expertise for a limited program.

Second, the proposed MRLs are very low - are these numbers truly achievable or even necessary? 

And, at these very low MRLs, some contaminants could be ubiquitous - what will the data mean? 

AMWA notes that EPA has determined MRLs by starting with the analytical capability (i.e., from a 

baseline, lower MRL) and using the lowest concentration minimum reporting level (LCMRL) 

approach to estimate the MRL up to what appears to be the lowest level feasible. AMWA

recommends instead that EPA start with the end in mind. Specifically, the purpose of the UCMR is 

to inform the regulatory process by gathering occurrence data. Therefore, EPA should set the MRLs 

for UCMR3 contaminants based on a fraction of the health reference level (HRL) for an analyte 

(such as 1/10 of the HRL) that has been identified for the contaminant (if available) and if the 

method is capable of meeting that level (and the LCMRL provides guidance on this capability).

EPA determined feasibility of achieving the proposed MRLs by checking with a very small number 

of the best laboratories in the country to see whether these LCMRLs could be achieved; AMWA 

asks EPA to consider whether many laboratories will be able to achieve these levels. By setting the 

MRL as a fraction of the HRL, EPA will help ensure that far more laboratories will be able to 
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reliably achieve the MRL and also that the data collected will be higher quality data because it will 

not be as close to method limitations. 

Third, with regard to the methods proposed, AMWA recommends that EPA clearly describe in the 

final rule how the rule will address positive field blank samples. In the case where the method has 

not specified a field blank, MRLs are extremely low and field contamination has been reported as an 

issue in the literature (i.e., method 539), AMWA recommends that EPA include this in the final rule. 

This is especially important for the hormone samples where there is a high potential for 

contamination of the sample in the field, particularly in light of the low MRL. 

Response: Regarding your comments on laboratory capacity, EPA believes that a sufficient number 

of laboratories will be approved to handle the sample volume generated by UCMR 3, based on our 

experience with UCMR 2 and on consideration of the UCMR 3 methods. 

Regarding your comments on MRLs, the types of laboratories used for LCMRL studies, and field 

blanks, please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Diane VanDe Hei

Commenter Organization: Association of Metropolitan Water Agencies (AMWA)

Letter ID: 0070

Comment ID: 31780

Comment Code: 40000

Comment: 14. MRL definition

As noted in Comment 10, above, AMWA urges EPA to reconsider the proposed MRL definition. 

Response: Please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Randy Gottler

Commenter Organization: City of Phoenix Water Services Department (WSD)

Letter ID: 0091

Comment ID: 31784

Comment Code: 40000

Comment: This transmits comments of the City of Phoenix Water Services Department (WSD)

regarding the Notice of Proposed Rulemaking - Revisions to the Unregulated Contaminant 

Monitoring Regulation (UCMR 3) for Public Water Systems 

April 29, 2011 Water Docket United States Environmental Protection Agency Mail Code 282211 T

1200 Pennsylvania Avenue, NW. Washington, DC 20460 Attention Docket ID No. OW-2009-0090

Re: City of Phoenix Water Services Department Comments on the Notice of Proposed Rulemaking 

Docket ID No. OW -2009-0090 Revisions to the Unregulated Contaminant Monitoring Regulation 

(UCMR 3) for Public Water Systems
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This transmits comments of the City of Phoenix Water Services Department (WSD) regarding the 

Notice of Proposed Rulemaking referenced above. Our specific comments follow the order of 

appearance in the rules and are not necessarily in order of importance to our agency. 

Analytical Requirements - Lowest Concentration Minimum Reporting Level (LCMRL) EPA 

proposes to implement a new method to determine the Minimum Reporting Level (MRL) for 

monitoring performed for UCMR3. The new method utilizes multiple statistical models in a 

complex multiple step process. The WSD believes the LCMRL procedure outlined in the laboratory 

approval manual will lead to sequence failures due to the requirement to verify the MRL with each 

analytical batch to within 80 to 100 percent of true value. It is our belief that the procedure will 

generate levels that are not appropriate and too low to consistently generate acceptable data per the 

UCMR Data Quantification Objectives. The WSD recommends EPA consider a simpler more 

transparent process like that recommended by the Federal · Advisory Committee on Detection and 

Quantification, which is based on providing study laboratories known concentrations of a parameter 

and empirically determining the lowest level at which the laboratories can accurately measure the 

target analyte. This approach determines if laboratories can achieve a measurement quality objective 

in a transparent manner easily understood and accessible to interested parties.

Response: Regarding your comments on MRL verification and the possibility of sequence failures, 

the analytical methods that were developed for use in UCMR 3 and the UCMR 3 Laboratory 

Approval Requirements and Information Document indicate that MRL verification is required 

within 50-150% of the true value, not 80-100%. In UCMR 2 the MRLs were demonstrated to be 

reliable reporting levels. The LCMRL procedure and MRL procedures being used for UCMR 3 are 

not altogether new procedures, but they have been made to be more robust and they more 

accurately take into account inter-laboratory variability.

Regarding your comment on possible use of the FACDQ procedure, please see the response to 

comment code 40000 Minimum Reporting Level Determination/LCMRLs.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31803

Comment Code: 40000

Other EPA Comment Codes and Descriptions: 36010 EPA Method 537 Rev 1.1 - PFCs

Comment: b. EPA should rely on actual laboratory blank analytical results to factor laboratory 

background contamination into the determination of final UCMR MRLs for perfluorinated 

chemicals.

EPA proposes to use a statistical methodology as the basis for Lowest Concentration Minimum 

Reporting Levels (LCMRLs) and MRLs in UCMR 3 (76 FR 11720).

Trace analysis for chemicals that are common laboratory contaminants warrants a different 

approach than the proposed LCMRL/MRL methodology to minimize false positives. The Federal 

Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act 
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Programs (FACDQ) expressed concern about false positives, recommending "a<=1% false positive 

rate be used for detection" (FACDQ, 2007).

Method 537 recognizes the potential for background contamination and invalidates results where 

the laboratory blank exceeds 1/3 of the MRL, effectively indicating that results within a factor of 3 

of the MRL should be considered non-detect. However, longstanding EPA data validation 

guidelines provide for qualifying sample results within 5 times the value of the highest laboratory 

blank associated with an analytical batch as non-detect (EPA, 1999; EPA Region IV, 1999). 

Consistent with this approach, the 1/3 MRL threshold would be replaced by a 1/5 MRL threshold. 

Risha et al. (2005) used 20% of the lower limit of quantitation (LLOQ) as the criterion for the 

absence/presence of significant interferences in the analysis of compounds including PFOA and 

perfluorononanoic acid (PFNA). These authors "recommended that a standard solution be run on 

the LC/MS/MS corresponding to the estimated LLOQ (25 ng/L) in matrix and a signal-to-noise 

ratio be obtained for the analyte transition of at least 5:1 compared to a reagent blank." In this way, 

Risha et al. (2005) assured a consistent way for assuring that results reported at or above the LLOQ 

(equivalent to MRL) were clearly distinguishable from background contamination present in the 

laboratory. 

The FluoroCouncil agrees with the following statement from Section 9.3.1. of Method 537 (Version 

1.1), "Because background contamination is a significant problem for several method analytes, it is 

highly recommended that the analyst maintain a historical record of LRB data." These Laboratory 

Reagent Blank data would provide the information needed to have a sufficient population of actual 

laboratory blank results (e.g., =10) to serve as the basis for calculating MRLs as 5 times the average 

blank data. A laboratory could begin assembling its historical record of LRB data during Proficiency 

Testing (as part of the Laboratory Approval Process) prior to the start of UCMR 3 monitoring. EPA 

could assess Proficiency Testing blank results against a set of target MRLs as part of its evaluation 

and approval of laboratories for UCMR 3 perfluorinated chemical monitoring. 

Setting MRLs for perfluorinated chemicals in the final UCMR 3 regulation to 5 times the average 

blank level (rather than through the approach described in the LCMRL document accompanying the 

proposed UCMR 3 regulation) would make Method 537 reporting for UCMR 3 consistent with the 

ultimate reporting approach supported by EPA data validation guidelines (EPA, 1999; EPA Region 

IV, 1999; EPA, 2008).

In addition, the FluoroCouncil recommends that EPA set MRLs for UCMR 3 laboratories 

performing perfluorinated chemical analysis at 5 times the laboratory’s average blank level to assure 

that UCMR 3 concentrations are representative of actual concentrations rather than background 

contamination. Alternatively, EPA could prescribe national MRL values in Table 1 of the final 

UCMR 3 regulation that take available data (including those generated during demonstration testing 

proposed in comment 2) on laboratory background contamination (e.g., 25 ng/L MRL for PFOA 

based on 5 ng/L background) into account and then require UCMR 3 laboratories performing 

perfluorinated chemical analysis to demonstrate background levels less than or equal to 1/5 of the 

MRL on an ongoing basis during UCMR 3 monitoring. 

c. UCMR 3 procedures should provide for routine analysis of laboratory and field blanks for 

adequate assessment and qualification of pefluorinated chemical blank contamination. 
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Section 9.3.1 of Method 537 (Version 1.1) requires analysis of a Laboratory Reagent Blank with each 

analytical batch and states "Background from method analytes or other contaminants that interfere 

with the measurement of method analytes must be below 1/3 of the MRL". Section 9.3.8 of Method 

537 (Version 1.1) notes "Analysis of the FRB [Field Reagent Blank] is required only if a Field Sample 

contains a method analyte or analytes at or above the MRL".

Longstanding EPA data validation guidelines provide for qualifying sample results within 5 times the 

value of the highest laboratory blank associated with an analytical batch as non-detect (EPA, 1999; 

EPA Region IV, 1999). More recent EPA guidelines (EPA, 2008) effectively continue this practice, 

especially for laboratory blanks or field blanks containing common laboratory contaminants relevant 

to the target analytes.

Method 537 or the final UCMR 3 regulation should allow for qualifying low level apparent 

detections within a factor of 5 of the highest laboratory blank in the corresponding analytical batch 

as non-detects, in addition to those situations with greater than or equal to 1/3 the MRL where 

Method 537 specifies re-analysis or re-sampling. Additionally, in order to maximize the utility of the 

laboratory blanks for assessing background contamination, it is important for EPA to assure that 

each UCMR 3 perfluorinated chemical analytical laboratory consistently concentrates the extract to 

the same fixed final volume (see comment 2) and to always use the same volumes for lab blanks as 

are used for study samples through periodic EPA audits of the laboratories performing UCMR 3 

analysis for perfluorinated chemicals.

In order to ensure that background contamination in the laboratory is not included in the UCMR 3 

data set as actual results, analytical laboratories must be required to take special measures to reduce 

the possibility of cross- contamination, MRLs must adequately factor in laboratory blank 

contamination levels, a sufficient number of blanks must be collected, analyzed, and assessed, and 

water systems must be allowed to qualify apparent detections within 5 times the highest blank in 

corresponding analytical batch as non-detects.

Response: Regarding your comments on invalidating results due to background contamination, 

EPA has evaluated LRB data and they easily meet the "1/3 of MRL" requirement of the method. 

The "long standing EPA data validation guidelines from Region IV" were developed for Region IV's 

superfund contract work and are not directly relevant to drinking water analysis nor has this ever 

been a drinking water guideline. http://www.epa.gov/region4/sesd/oqa/rassop-organics.pdf. 

Regarding your comments on the FACDQ procedure and field blanks, please see the response to 

comment code 40000 Minimum Reporting Level Determination/LCMRLs. 

Please see response to comment code 36010 EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31806

Comment Code: 40000
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Comment: 4. EPA's proposed new LCMRL approach is flawed and, to ensure it results in the 

development of accurate and reliable information, needs independent technical review before reproposal for potential use in a regulatory setting. 

EPA has proposed "revisions to the definition of the minimum reporting level (MRL)" (76 FR 

11719) that reflect "improvements in the statistical procedures for determining the LCMRL and 

MRL" (76 FR 11719). The Agency requested comment "regarding the proposed definition of MRL" 

(76 FR 11720) after briefly describing the statistical procedure for estimating the LCMRL and, in 

turn, the computation of MRL. The introduction to the LCMRL Calculator tool document 

announced in the proposal ("Technical Basis for the Lowest Concentration Minimum Reporting 

Level (LCMRL) Calculator," EPA, 2010) notes, "The MRL may be useful as an alternative to the 

PQL [practical quantitation limit] for setting future regulatory limits" (p. 2 of 24). The closing 

section of this LCMRL Calculator tool document states, "Although the procedure is complex and 

computationally intensive, implementing it in user-friendly software in the public domain and freely 

available over the internet makes it easy for laboratories to use" (p. 22 of 24).

In fact, the LCMRL Calculator Tool document begins to describe an extremely complex procedure 

for establishing LCMRLs and MRLs that is not warranted in UCMR 3 and that is not an appropriate 

alternative to the PQL for other regulatory purposes. Furthermore, the document is incomplete in 

several ways:

1) The document lacks a practical start to finish demonstration of how these calculations should be 

done. 2) Contrary to basic science and engineering principles, the document does not present 

comparative examples or otherwise demonstrate a reasonable return for investing the extra effort 

required for its computational approach relative to the LCMRL methodology used for UCMR 2. 3) 

EPA’s claim in the document that Bayesian bootstrapping is applicable to very small datasets, while 

"ordinary" bootstrapping is not, is not supported by, and seems contrary to, the Bayesian literature 

(e.g., Parzen et al., 2005, and Gu, et al., 2008). If Bayesian bootstrapping is in fact applicable to very 

small datasets, that should be shown by appropriate citations and subjected to further review. 4) The 

document’s general claims of "improvements" via adoption of the highly complex approach therein 

for computing the prediction variance in comparison to the methods of Rocke and Lorenzato 

(1995), EPA (2004), or Helsel (2005) have not been shown to be grounded in real data. 5) No 

specific reference is included in the document for the Matlab and R code used in the LCMRL 

calculations, thereby making it difficult to comment on the accuracy of the code or any limitations 

the code may have.

The document requires extensive revision to fill in the above enumerated gaps to provide adequate 

documentation and explanation of the separate "black box" LCMRL calculator tool proposed for 

use by UCMR 3 laboratories. Furthermore, the statistical approaches used in the proposed LCMRL 

Calculator tool do not appear to address the potential for false positives due to background 

contamination of chemicals typically present in analytical laboratories, as is the case for

perfluorinated chemicals in UCMR 3. 

Not only is the approach in the LCMRL Calculator tool document technically flawed, but it has not 

been subjected to the necessary peer review and public comment pursuant to information quality, 

transparency, and administrative procedural requirements. EPA should refrain from further use of 

the proposed revised LCMRL approach in UCMR 3 until it has undergone proper review and 

comment. To do otherwise would disregard EPA’s own information quality and peer review 
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guidance, along with the Administration’s emphasis on transparency and openness in the regulatory 

process.2

Following incorporation of the suggested revisions described above, EPA should seek technical, 

independent peer review of the LCMRL document. With similar documents and methodologies, 

EPA has convened Science Advisory Board (SAB) panels to provide the Agency with its 

independent assessment and recommendations. We urge EPA to consider convening a SAB panel of 

laboratory data validation experts, analytical chemists, and statisticians as a possible approach to 

obtaining the needed peer review of the revised LCMRL document. As FACDQ stated in its 2007 

final report, "Looking ahead to further work by EPA on procedure/s for detection and quantitation, 

the Committee recommended that a formal peer review of the procedure proposed for 

promulgation be undertaken and that a follow up pilot study be completed to confirm the 

performance of whatever procedure(s) EPA proposes to promulgate." 2 See Pub. L. No. 106-554; 

U.S. EPA, Guidelines for Ensuring and Maximizing the Quality, Objectivity, Utility, and Integrity of 

Information Disseminated by the Environmental Protection Agency (Oct. 2002) (establishing the 

appropriate administrative mechanisms and review processes for ensuring the quality of influential 

information disseminated by EPA. As the underlying foundation for the MRLs proposed in the 

UCMR 3, the FluoroCouncil considers the LCMRL approach to be unarguably influential.); Peer 

Review Handbook, 3rd Edition, U.S. EPA, Science Policy Council, January 2006, EPA 100-B-06-

002, at http://www.epa.gov/peerreview/pdfs/peer_review_handbook_2006.pdf (requiring peer 

review for scientific and technical work products that support a regulatory program and establish "a 

significant precedent, model, or methodology," which, the FluoroCouncil contends, includes the 

LCMRL approach used in the UCMR 3). See also Exec. Order No. 13,563, 76 Fed. Reg. 3821 (Jan. 

21, 2011) (emphasizing the need for public participation and transparency in the rulemaking process 

and the importance of ensuring "objectivity of any scientific and technological information and 

process used to support the agency’s regulatory actions"). 

Following independent peer review, if EPA still wishes to utilize the revised LCMRL approach in a 

regulatory context, the Agency should first issue the revised document (and accompanying computer 

code) for public notice and comment. In the interim, an alternate approach to establishing MRLs for 

perfluorinated chemicals is proposed earlier in these comments (see comment 1). For the other

UCMR 3 constituents, use of the LCMRL approach currently used under UCMR 2 may be 

appropriate. 

Response: Regarding your comments on the complexity of the LCMRL procedure and issues of 

false positives, please see the response to comment code 40000.

Regarding the comment on the application of Bayesian bootstrapping, EPA's purpose in applying 

the Bayesian bootstrap is to estimate the distribution of LCMRL values that could be expected if a 

laboratory were to run repeated LCMRL experiments. The LCMRL is a statistic, like the mean, 

median, quantile or a regression slope. 

There are several ways to estimate the sampling distribution of a statistic. In the simplest case, its 

exact distribution is known. This is not the case for the LCMRL. 

The Bayesian bootstrap (BB) is similar to Efron’s bootstrap except that the weights are drawn from 

the uniform distribution on the n-1 dimensional simplex itself (the n-1 dimensional Dirichlet 

distribution with all parameters equal to 1), rather than from a lattice embedded in it that the 
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classical bootstrap uses. As a result, although the BB does suffer "lumpiness" in small samples, this 

"lumpiness" is always less than with the classical bootstrap (Rubin 1981). Also, the variance of the 

BB resampling distribution of a statistic is always lower than that of the resampling distribution 

under the classical bootstrap because the variance of the weight distribution is smaller (Rubin 1981). 

The classical bootstrap and the BB may be regarded as members of the class of weighted bootstraps 

(Barbe and Bertail, 1995). Within that class, an estimator based on the sample of BB replicates of a 

statistic is an approximation to a Bayes estimator, since the BB samples from the posterior 

distribution of the parameter (Rubin 1981). As a Bayes estimator (actually a limit of proper Bayes 

estimators) it must have excellent frequentist properties as well, including admissibility. In this case, 

the LCMRL is viewed as a parameter of the joint distribution of the (x, y) values. 

EPA believes that using a BB in this application is the best of all of the possible methods for 

estimating the sampling distribution of the LCMRL. 

References:

Barbe, P. and P. Bertail, (1995) The Weighted Bootstrap, Lecture notes in Statistics, Vol. 98, 

Springer-Verlag.

Rubin, D. (1981) "The Bayesian Bootstrap" Annals of Statistics.9, 130-134.

Commenter Name: Jessica Steinhilber

Commenter Organization: FluoroCouncil 

Letter ID: 0075

Comment ID: 31807

Comment Code: 40000

Other EPA Comment Codes and Descriptions: 36010 EPA Method 537 Rev 1.1 - PFCs

Comment: 5. Conclusion 

Overall, the FluoroCouncil is concerned that, as proposed, Method 537 and other requirements for 

UCMR 3 monitoring of perfluorinated chemical occurrence in drinking water will lead to the 

generation of inaccurate data, inappropriate as the basis for future regulation. Additionally, the 

proposed new LCMRL approach should not be implemented in support of UCMR 3 or any other 

rulemaking without appropriate peer review and additional public comment. 

We appreciate the opportunity to provide information and comment on the proposed UCMR 3. In 

addition, we would welcome the opportunity for our technical experts to meet with EPA to discuss 

our suggestions to minimize laboratory background contamination and to improve Method 537 

prior to its use in UCMR 3. If you have any questions or would like to arrange a meeting, please 

contact Jessica Steinhilber at 202-249-6737 or jessica_steinhilber@americanchemistry.com.

Sincerely,

Jessica S. Steinhilber FluoroCouncil 

Appendix: References
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APPENDI

XReferences

Barton, C.A, Botelho, M.A., and Kaiser, M.A., 2008. "Solid Vapor Pressure and Heat of Sublimation 

for Perfluorooctanoic Acid, J. Chem. Eng. Data, C., 53, 939-941.

Barton, C.A., Botelho, M. A., and Kaiser, M.A., 2009. "Solid Vapor Pressure and Heat of 

Sublimation for Ammonium Perfluorooctanoate, J. Chem. Eng. Data, 54(3), 752-755.

de Voogt, P. and Saez, M., 2006. "Analytical chemistry of perfluoroalkylated substances", Trends in 

Analytical Chemistry, 25, 326-342.

EPA, 1999. "USEPA Contract Laboratory Program National Functional Guidelines for Organic 

Data Review", OSWER 9240.1-05A-P, PB99-963506, EPA540/R-99/008.

EPA Region IV, 1999. "Data Validation Standard Operating Procedures for Contract Laboratory 

Program Routine Analytical Services", revision 2.1, Science and Ecosystem Support Division, Office 

of Quality Assurance.

EPA, 2004. "Statistical Protocol for the Determination of the Single-Laboratory Lowest 

Concentration Minimum Reporting Level (LCMRL) and Validation of Laboratory Performance at 

or Below the Minimum Reporting Level (MRL)", EPA Document # 815-R-05-006.

EPA,2008. "USEPA Contract Laboratory Program National Functional Guidelines for Superfund 

Organic Methods Data Review", OSWER 9240.1-48, USEPA-540-R-09-01.

FACDQ (Federal Advisory Committee on Detection and Quantitation Approaches and Uses in 

Clean Water Act Programs), 2007. Report of the Federal Advisory Committee on Detection and 

Quantitation Approaches and Uses in Clean Water Act Programs.

Gu, J., Ghosal, S., and Roy, A., 2008. "Bayesian Bootstrap Estimation of ROC Curve", Stat Med, 

27(26), 5407-20.

Helsel, D.R., 2005. Nondetects and Data Analysis. Wiley, Hoboken, New Jersey.

Hori, H., Hayakawa, E., Yamashita, N., Taniyasu, S., Nakata, F., and Kobayashi, Y., 2004. "Highperformance liquid chromatography with conductimetric detection of perfluorocarboxylic acids and 

perfluorosulfonates", Chemosphere, 57, 273-282.

ISO, 2009. ISO 25101 - Water Quality - Determination of perfluorooctanesulfonate (PFOS) and 

perfluorooctanoate (PFOA) - Method for unfiltered samples using solid phase extraction and liquid 

chromatography/mass spectrometry.

Kaiser, M.A., Larsen,B.S., Kao, C.P.C. and Buck, R.C., 2005. "Vapor pressures of perfluorooctanoic, nonanoic, -decanoic, -undecanoic, and -dodecanoic acids", J. Chem. Eng. Data, 50, 1841-

1843.
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Kaiser, M.A., Barton, C.A., Botelho, M.A., and Dawson, B.J., 2010."Understanding potential 

exposure sources of perfluorinated carboxylic acids in the workplace", M. A. Kaiser, C. A. Barton, 

M. A., The Annals of Occupational Hygiene, 54, 915-922.

Larsen, B.S. and Kaiser, M.A., 2007. "Challenges in perfluorooctanoic acid measurements", Anal. 

Chem., 79, 3966-3973.

Martin, J.,Kannan, K., Berger, U., de Voogt, P., Field, J., Franklin, J., Giesy, J. P., Harner, T., Muir, 

D.G.C., Scott, B., Kaiser, M., Jaernberg, U., Jones, K.C., Mabury, S.A., Schroeder, H., Simcik, M., 

Sottani, C., Van Bavel, B., Kaerrman, A., Lindströem, G., and van Leeuwen, S., 2004. "Analytical 

challenges hamper perfluoroalkyl research", Environ. Sci. & Tech., 38(13), 248A-255A.

Parzen, M.,Lipsitz, S.R., and Fitzmaurice, G.M., 2005. A note on reducing the bias of the 

approximate Bayesian bootstrap imputation variance estimator, Biometrika 92 (4), 971-974.

Risha, K., Flaherty, J., Wille, R., Buck, W., Morandi, F. and Isemura,T., 2005. "Method for Trace 

Level Analysis of C8, C9, C10, C11, and C13 Perfluorocarbon Carboxylic Acids in Water", Anal. 

Chem., 77, 1503-1508.

Rocke,D.M. and Lorenzato, S., 1995. "A two-component model for measurement error in analytical 

chemistry", Technometrics 27, 176-184.

Shoemaker, J.A., Boutin, B.,and Grimmett, P., 2009. "Development of a U.S. EPA drinking water 

method for the analysis of selected perfluoroalkyl acids by solid-phase extraction and LC-MS- MS", 

J. Chromatogr. Sci., 47, 3-11.

Taniyasu, S., Kannan, K., So M.K.,Gulkowska, A., Sinclair, E., Okazawa, T., and Yamashita, N., 

2005. "Analysis of fluorotelomer alcohols, fluorotelomer acids, and short- and long-chain 

perfluorinated acids in water and biota", J. Chrom. A., 1093, 89-97.

Yamashita,N., Kannan, K., Taniyasu, S., Hori, Y., Petrick, G., and Gamo, T., 2005. "A global survey 

of perfluorinated acids in oceans", Marine Pollution Bulletin, 51,658-668.

Response: Please see the response to comment codes 40000 Minimum Reporting Level 

Determination/LCMRLs and 36010 EPA Method 537 Rev 1.1 - PFCs.

Commenter Name: Nira Yamachika

Commenter Organization: Orange County Water District (OCWD)

Letter ID: 0052

Comment ID: 31849

Comment Code: 40000

Comment: 5.0 Laboratory Lowest Concentration Minimum Reporting Levels (LCMRL) 

UCMR3 uses a new statistical-based process to determine the laboratory lowest concentration 

minimum reporting level (LCMRL) as defined as the lowest spiking concentration at which recovery 
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of between 50 and 150% is expected 99% of the time by a single analyst. The preamble and 

regulatory language provides some key points on the process (FR page 11719, 141.40(a)(5)(iii):

* The LCMRL is estimated using sophisticated statistical procedures that have been incorporated 

into an LCMRL calculator tool that is available on EPA’s Web site.

* The statistical tool estimates probability distribution for spike recover...requires regression 

modeling 

* Variance model is estimated using a Generalized Linear Model

* The combined procedure provides a robust estimator of the LCMRL and sophisticated and useful 

measure of method capability OCWD recommends that the process proposed for the UCMR 

program is less complex and easier to understand by the users who produce the analytical results and 

PWSs who must approve posted data. The procedure is very complicated and uses numerous 

statistical procedures and models. OCWD suggests consideration of procedures that are more 

transparent and user friendly. For example, the CA Department of Public Health provides 

laboratories with samples of known concentration, to analyze, and determine at what concentration 

the laboratories could accurately measure the target analytes.

Response: Please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Gary Buchanan, PhD. 

Commenter Organization: State of New Jersey DEP

Letter ID: 0067

Comment ID: 31891

Comment Code: 40000

Comment: Technical Comments to the Revisions to the Unregulated Contaminant Monitoring 

Regulation (UCMR3) for Public Water Supplies (FR 76: 11713-11737, March 3, 2011)

Comments on Analytical Issues: Determination of Minimum Reporting Level (MRL) 

Regardless of whether the interlaboratory MRL is determined by the current method or by the new 

method proposed in the proposed UCMR3, it is important that it be based on data from individual 

laboratories that are using the same analytical methodology data. Individual laboratory data should 

be pooled only from laboratories using "equivalent instrumentation sensitivities." For example, the 

perfluorinated chemical (PFC) analytical methods allow for the utilization of several instrument 

configurations all with different sensitivities for the parameters determined in the method. In the 

NJDEP investigation of analytical capability for PFCs, data were submitted by several certified labs. 

One of the laboratories had sensitivity levels that were an order of magnitude lower than the others. 

In cases such as this, the statistical spread for interlaboratory data is so large that it will generate a

pooled interlaboratory reporting limit that is inappropriately high for regulatory use. Furthermore, 

the NJDEP recommends that the intralaboratory lowest concentration minimum reporting level 

(LCMRL) be determined using the approach presented in Winslow et al. (2006), 
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Response: Regarding your comments on instrument sensitivities, EPA addresses issues of varying 

instrument sensitivities as part of analytical method development. Regarding your comments on the 

Winslow, et al., (2006) procedure, the procedure presented in Winslow, et al. (2006) was used to 

generate LCMRLs and MRLs as part of the development of UCMR 2. For UCMR 3, EPA improved 

and updated the Winslow, et al. (2006) procedure to provide more robust estimators of the MRL. As 

to the statistical spread having an adverse impact on the final MRL, please note in (USEPA, 2012) 

that the MRL procedure does compensate for this issue however, EPA agrees that the potential for 

this increased variance to impact MRLs, this was an issue for these data. If this increased variance 

had impacted the MRLs it would have been to increase them. EPA notes that the MRLs determined 

for the UCMR 3 are sufficiently low, based upon the available health information. 

References:

Stephen D. Winslow, Barry V. Pepich; John J. Martin; George R. Hallberg; David J. Munch; 

Christopher P. Frebis; Elizabeth J. Hedrick; Richard A. Krop. 2006. "Statistical Procedures for the 

Determination and Verification of Minimum Reporting Levels for Drinking Water Methods." 

Environ. Sci. Technol., 40(1), 281-288.

USEPA. 2012. UCMR 3 Laboratory Approval Requirements and Information Document. Version 

2.0. EPA 815-R-11-003.

Commenter Name: Danielle Blacet

Commenter Organization: Association of California Water Agencies

Letter ID: 0077

Comment ID: 31892

Comment Code: 40000

Comment: 5.0 Laboratory Lowest Concentration Minimum Reporting Levels (LCMRL) 

The basic concept advanced in the LCMRL seems entirely reasonable and appropriate, to find the 

lowest concentration where competent laboratories can measure the analyte of interest within 

specified limits of accuracy. The proposed limits of plus or minus 50% seems entirely reasonable 

and appropriate and the requirement for on-going verification is also completely prudent. Moreover 

having several laboratories involved in the development of the MRL is excellent.

With all of that said, the proposed laboratory and statistical procedures seem inordinately, indeed 

gratuitously complex and onerous. The most recent Technical Report ("Technical Basis for the 

Lowest Concentration Minimum Reporting Level (LCMRL) Calculator," EPA 815-R-11-001, 

December 2010) rightly notes that "...the procedure is complex and computationally intensive...", 

which is probably an understatement. A procedure that laboratories themselves cannot actually 

perform, or even understand, is probably not beneficial to anyone. Moreover it would create a 

situation where the study would be unnecessarily expensive and completely opaque to anyone not 

intimately involved. ACWA favors a procedure that is as simple, inexpensive, and transparent as 

possible. 

As an alternative, it is worth considering the approach taken by the recently concluded Federal 

Advisory Committee on Detection and Quantitation or the methodology used by the Drinking 
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Water Program in California. In both cases, the approach taken was simply to provide the study 

laboratories with samples of known concentration and empirically determine at what concentration 

the laboratories could accurately measure the target analytes. This would produce an LCMRL that 

not only meets the Measurement Quality Objectives of the UCMR3 but be produced in a way that 

would be transparent and accessible to all interested parties.

Response: Regarding your comments on the complexity of the LCMRL procedure and the 

FACDQ procedure, please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32039

Comment Code: 40000

Comment: 4. Setting minimum reporting levels for UCMR3 analytes that do not undermine the 

credibility of the dataset.

Response: Please see the response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32087

Comment Code: 40000

Comment: Setting a Sound MRL EPA typically sets trigger levels for regulatory compliance

monitoring based on analytical capability alone when the analytical method is not capable of 

reaching the HRL (e.g. bromate in the Stage 1 Disinfectants and Disinfection Byproducts Rule). 

Using the LCMRL to determine MRLs, regardless of the HRL is contrary to the purpose of the 

UCMR3 monitoring, which is to determine occurrence in the range of concentrations relevant to 

public health protection that would be afforded by a new drinking water standard. Consequently, the 

occurrence data must be sound and at relevant levels for the regulatory development process. 

Two alternative approaches can be used to set MRLs for the UCMR3 program. One can either 

develop an MRL based on the lowest achievable analytical level or one can develop an MRL as a 

fraction of the HRL. These comments will refer to these as "bottom up" and "top down" 

approaches respectively. EPA has developed the LCMRL) approach as a "bottom up" way of 

determining analytical feasibility for achieving a given reporting level with a single lab confidence 

interval of +/-50%. This approach does not adequately account for sources of variability that exist 

beyond the benchtop in a single or small group of expert laboratories processing samples prepared 

in distilled water. Rather, the emphasis should be on generating data relevant to decisions based on 

the analyte’s HRL.
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AWWA recommends the agency take a "top down" approach where solid HRL data are available. 

This approach is consistent with previous UCMR rulemakings. EPA should set the UCMR3 MRLs 

at a uniform factor below the HRL (such as 10X), as long as the cited method is demonstrated to 

achieve that level of reliably. The LCMRL can be used to support this determination. Where there 

are no HRL data (e.g. for some of the perfluorinated compounds that are not on the CCL3 list), 

EPA should establish reporting limits that are consistent with the other UCMR3 analytes in the 

method, even if the LCMRL is substantially lower for those compounds. The difference between 

these two approaches is important. For example, for strontium, the proposed reporting level is 0.3 

ug/L and the HRL is 4200 ug/L; consequently, the proposed reporting level is 14,000 times lower 

than the lowest HRL. Setting MRLs substantially below the HRL not only generates spurious lowlevel observations that subsequently distract data users, it also leads to poorer quality data in the 

actual concentration range of interest because the calibration range must reflect the target MRL. For 

strontium in particular we expect substantial amounts of data to be from 10 to 1000 times the 

proposed MRL. 

Lowest Concentration Minimum Reporting Level (LCMRL) Approach 

AWWA obtained the assistance of Mr. Jeffrey Rosen of TetraTech to review the Agency’s proposal 

to use the LCMRL to set the UCMR3 MRLs and to evaluate underlying premise for this approach as 

reflected in the Technical Basis for the Lowest Concentration Minimum Reporting Level (LCMRL) 

Calculator (Support Document).[FN15:2011. EPA. Technical Basis for the Lowest Concentration 

Minimum Reporting Level (LCMRL) Calculator. EPA 815-R-11-001.] Mr. Rosen’s analysis is

provided in Appendix 1. In summary, the review found that the LCMRL approach had merit for 

initial demonstrations of performance by individual laboratories seeking to perform an analytical 

method for a chemical analyte and submit data under UCMR3. The appropriateness of using the 

LCMRL approach to developing a MRL for reporting under the UCMR3 is less certain. 

Review of the support document by AWWA volunteers and Mr. Rosen found the document to be 

an incomplete description of the underlying agency analysis as to how the LCMRL, as calculated, 

can support setting a MRL that is applied to multiple laboratories. While reading the support 

document made it possible to understand the underlying logic of EPA’s approach, the document 

was not sufficiently clear or detailed to allow an appropriately a skilled statistician to replicate the 

agency’s analysis and thereby confirm if the agency’s proposed approach is valid (or not). AWWA’s 

review leads us to believe:

1. The agency appropriately pursued developing an analytical approach to address a diverse range of 

sources of variability in analyzing low-level chemical concentrations. 

2. The proposed approach has a significant underlying flaw in that it is dependent on and 

extrapolates from a very small dataset developed from the performance of a small group of expert 

laboratories (and hence a biased sample).

3. The proposed protocol used to establish an MRL based on LCMRL data is undertaken on an 

analyte-by-analyte basis. In practice performance must be realized on a method basis. To be 

effective the protocol must offer a means of reflecting practical performance across all analytes 

captured by a single method. This task is particularly important when the LCMRL approach is 

extended to determine a multiple laboratory MRL determination where the performance of the 

method with respect to specific target analytes will vary.
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4. As analytical methods pursue quantitation at very low concentrations and use increasingly 

sophisticated instruments, it is important that development of MRLs capture the effects of matrix 

on method performance. 

AWWA recommends that the agency take the following steps:

1. Continue to pursue the LCMRL approach for initial demonstration of individual laboratory 

performance. Modifying the procedure to address the weaknesses noted in AWWA’s comments.

2. Update and revise the technical support document to more clearly document the proposed 

application of the LCMRL to set multi-laboratory MRLs, and in doing so, conduct some simple 

statistical tests to see if simpler, more transparent algorithms are equally effective.

3. Work with AWWA and other stakeholders to develop a stronger and more disseminated method 

development network for drinking water analytical methods, including developing a more extensive 

roster of laboratories to test the performance of new methods and hence support development of a 

more robust understanding of method performance. 

4. Employ a top-down approach to setting UCMR3 MRLs that balances our ability to detect 

contaminants at the concentrations relevant to given HRLs. 

Response: Regarding your comments on setting MRLs in consideration of HRLs, the complexity of 

the LCMRL/MRL procedures, and on the types of laboratories used for LCMRL studies, please see 

the response to comment code 40000 Minimum Reporting Level Determination/LCMRLs. 

Regarding your comment on setting MRLs on a method basis in contrast to an analyte basis, the 

performance of analytes within an analytical method are highly dependent upon the analyte. The 

LCMRL and MRL procedures take into account the variance observed from a number of 

laboratories for each analyte of interest within a particular analytical method. The amount of interlaboratory variance for each analyte is reflected in the MRLs - the greater the variance, the greater 

the MRL.

Regarding your comment on MRLs capturing matrix effects, the determination of matrix impact is 

made separately within the method development process.

Regarding your comment on EPA working with Stakeholders on method development, EPA has 

and will continue to work with all parties in the development of new analytical methods.

Commenter Name: Thomas W. Curtis

Commenter Organization: American Water Works Association (AWWA)

Letter ID: 0080

Comment ID: 32106

Comment Code: 40000

Comment: Appendix 1 
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Expert Review of Technical Basis for the Lowest Concentration Minimum Reporting Level 

(LCMRL) Calculator

Review of the Statistical Methods Recommended for the LCMRL and the MRL The Revisions to 

the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems proposed 

rule (FR Vol 76, No. 42, March 3, 2011, Pp 11713- 11737), suggest a modified approach to defining 

the Lowest Concentration Minimum Reporting Level (LCMRL) and associated with this a new 

method for defining the Minimum Reporting Level (MRL). The LCMRL is laboratory specific while 

the MRL is based on three or more expert laboratories completing a set of samples by a very specific 

protocol. The results of these three or more expert laboratories are then processed through a 

statistical procedure that is described in the document: 

"Technical Basis for the Lowest Concentration Minimum Reporting Level (LCMRL) Calculator" 

(Office of Water (4607M), EPA 815-R-11-001, December 2010.)

Underlying Premise: As described in the proposed UCMR3 and support documentation the LCMRL 

has two applications. The first is for use by a single laboratory as a means of demonstrating 

analytical method performance. The second and more challenging application is predicting what is 

the MRL should be for laboratories using a given method to analyses for a specific analyte.

The robust statistical methods that are recommended eliminate some of the problems with earlier 

method by eliminating the need to make assumptions about normality of the data and homogeneity 

of the variance which are often not the case with environmental data. In addition, the data are by 

definition left truncated and these methods are not severely limited by this reality. The use of

prediction intervals in this instance is appropriate and ensures that the LCMRLs and the MRL 

should be attainable by most laboratories that are capable of analyzing for these analytes. The 

LCMRL methodology for each laboratory’s initial demonstration of capabilities (IDC) is very 

straight forward. On the negative side the underlying statistical approaches are not easily 

understood. The technical support document is not at all clear and does not lend confidence to the 

chemists performing the work or the stakeholder community. There are also assumptions made that 

are not exactly correct like: "The distribution of pooled BB (Bayesian bootstrap) replicates, 

generated from the LCMRL study data for a sample of experienced drinking water laboratories 

approximates the distribution of estimated LCMRL values which might be generated from the 

population of experienced drinking water laboratories" this assumption is probably not correct and 

if it is a critical assumption then the results of these analyses are not correct. The approach 

recommended in the support document is very complex and it is not clear that the complexity adds 

much to the result. It certainly creates discomfort with the MRL as a result of experienced analysts 

and engineers not being able to follow and readily duplicate the underlying analysis of the statistical 

approach proposed. 

Lack of Transparency Since the establishment of the reporting levels is a critical consideration the 

process needs to be clear and transparent regarding how the MRL is developed. This report 

addresses issues with the approach as described in the document referenced above.

The document is very complex and difficult to follow. In part this is due to the use of robust 

statistics and a Bayesian Bootstrap. It is understood that these are well documented approaches 

however, the document that is supposed to explain these approaches is very difficult to follow and 

includes a great deal of notation that is not standard. While most of the notation is explained in the 
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text it is not in a standard format usually used to explain statistics. Normally in the text when an 

equation is presented all elements of the equation are presented and explained immediately after the 

equation. In this document there is one page that gives some of the notation (page 4 of 24) but then 

for the rest of the equations, new notation including very complex subscripting and superscripting is 

defined inside the text. When the notation is reused further on in the document the notation is not 

explained again. This results in the reader needing to search the text to find the notation. The 

absence of an easy cross reference for the symbols used in this complex application makes following 

the presentation very difficult. 

Further, there are a few key references in this document that are textbooks which are not readily 

available. In some cases an approach is referenced in a book but the details of the pages, equations 

and sections of the book are not given. As an example of this on Page A-4 - The estimation of the 

MRL as the 95-75 Upper Tolerance Level references "Guttman non-parametric procedure"

(Guttman. I. 1970 Statistical Tolerance Regions: Classical and Bayesian. Hafner ress, Darien, Ct.). 

This reference is out of print. We were able to find the book at a few large University Libraries and 

it can be purchased as a rare out of print book but otherwise it is not readily available. Given that 

this is the final calculation of the MRL and the reference is difficult to access the approach should 

be presented in appendix A. It would be far more effective if the document included a detailed 

presentation of the procedure. 

A number of the methods used in this paper including the Huber Location estimator and weights 

(page 8 of 24) and the bootstrap (page A-1) are not standard methods because of the very small 

number of data points that are the basis of the resampling (e.g., ML calculations are based on 3 sets 

of 200 resamples taken from 28 data points each. The Huber Location estimator and weights as well 

as the bootstrap procedure are modified for these applications with no references. While there is an 

indication that the technical support document was peer reviewed, it is not clear that these method 

modifications have been adequately documented or that they are correctly applied. In the case of the 

bootstrap modification (page A-1) the text discusses the use of Dirichlet weights with no reference 

or explanation of the calculation. The exact methodology used in the bootstrap process is critical 

since, as stated correctly in the text, the robustness of the bootstrap results improves as the sample 

size increases. In this case the sample size of 28 is considered quite small. Further, the bootstrap has 

assumptions about the representativeness of the true population and independence of the samples. 

The MRL calculator is premised on using a very small data set. The text explains that these problems 

are mitigated through the use of the Dirichlet weights but of the technical support document does 

not explain how this is done. 

Along with improved documentation this document would be vastly improved if it presented a test 

data set and the code used to do the calculations. It seems that the author is conversant in R and 

likely did the analysis in that language. The inclusion of well documented code that includes variable 

definition, explanation of how each section of the code relate to the technical document, clear 

outputs including tables and graphs would help clarify the proposed procedures (both the LCMRL 

locator and the estimation of the MRL. In general each critical step should be explained and an 

example of the data used and the results would allow reviewers to replicate the analyses.

Examples of difficult notation include (but are not limited to): 

Page 7 of 24 equation 2 which appears pretty straight forward but is not standard notation and is not 

documented, what is Uj 
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Page 11 of 24 equation 8 is subscripted with "v" that is not defined anywhere. Similarly, at the next 

set of equations (with no equation number), the a, b and c are now subscripted with an s with no 

explanation. 

Page 16 - similar to the issues listed above for page 11 of 24 equation set 12 - av , ae , bv , be , cv , ce 

- would all benefit from some explanation. 

Page A2 - the notation w*ij is not explained in the general notation or in the text.

In Summary It is difficult to assess the scientific basis for the proposed LCMRL and MRL process 

proposed for UCMR3 based on the technical document referenced as the explanation and 

justification for the new procedure. For stakeholders to evaluate this new approach the 

documentation needs to be improved dramatically. Recommended improvements include: 

1. Clear and thorough documentation of all notation used in the document 

2. Presentation of all statistical calculations especially those that are in obscure references

3. Example data set

4. R program that runs the calculations on the example data set

5. Adequate internal documentation in the R code so the code is understandable 

Response: Please see response to comment code 40000 Minimum Reporting Level 

Determination/LCMRLs. Regarding the distribution of pooled Bayesian Bootstrap replicates, EPA 

disagrees that the pool of laboratories is restricted to "experienced" laboratories. EPA does not 

select only the most experienced laboratories to provide LCMRL data for the determination of 

MRLs for the UCMR program. EPA strives to include a diverse selection of laboratories for the 

LCMRL studies that have been conducted. 

Regarding the complexity of the document, EPA will consider revising the documentation to 

improve its readability.
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Comment Code: 41000 Laboratory Approval Process/Laboratory Capacity 

Summary Response to Comments on Laboratory Approval Process/Laboratory Capacity: 

With regard to a comment about positive Field Blanks and invalidating Field Sample data: if a Field 

Blank exhibits a detect that is >1/3 the MRL, this is indicative of a problem with either the sampling 

procedures or analytical procedures (or both) and EPA believes that the best course of action of 

action is to resample.

With regard to comments about Proficiency Testing (PT) samples: by conducting ongoing 

laboratory audits EPA will be able to evaluate laboratory’s analytical processes for all aspects of 

sample receipt, storage, processing, analysis and reporting of routine samples. This will provide a 

complementary mechanism along with the original PT study for uncovering any potential data 

issues, and ensuring that laboratories meet the quality requirements. 

Individual Comments

Commenter Name: Daniel J. Caldwell 

Commenter Organization: Johnson&Johnson 

Letter ID: 0057 

Comment ID: 31644 

Comment Code: 41000

Comment: The laboratory approval process proposed for the UCMR3 is rigorous and is necessary 

to assure that data generated by the study suitable for assessing the presence of hormones in 

drinking water. The laboratory approval process for participants in UCMR3 (76 Fed. Reg. 11720) is 

suitably rigorous to assure that only laboratories that can achieve the QA/QC requirements of 

Method 539 are accepted. The inclusion of proficiency testing (PT) for qualification is also 

important.

EPA should include analysis of proficiency test samples to complement laboratory audits during the 

2013-2015 monitoring period. EPA plans on conducting laboratory audits throughout the ongoing 

testing program (76 Fed. Reg. 11721). Satisfactory audit results will be required in order for a 

laboratory to maintain approval for participation. However, the analysis of PT samples will only 

occur before the monitoring program begins. We recommend that participating laboratories be 

required to analyze at least one PT sample during the monitoring program. The results of this 

analysis should not necessarily be used to disqualify a laboratory if they have a satisfactory audit. 

However, the results of this ongoing use of PT samples will serve as an additional check on the 

reliability of the monitoring data. Method 539 does not have any requirement that a laboratory 

analyze samples containing known amounts of the analytes that are prepared by an outside source 

and are therefore unknown to the analyst (PT samples). Requirements to test such samples are 

routine for laboratories in all of EPA’s Office of Water programs and should be included in 

UCMR3.

Summary
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We appreciate EPA’s consideration of these comments, developed in consultation with our industry 

Pharmaceuticals in the Environment Task Force, and particularly recommend that EPA emphasize 

the natural sources of the majority of the target hormones and maintain rigorous analytical and data 

quality procedures. If you have any questions about our comments, please contact me at 732-524-

1088 or by email: dcaldwel@its.jnj.com.

Sincerely, Daniel J. Caldwell, PhD Principal, Environmental Toxicology 

Response: Please see the response to comment code 41000 Laboratory Approval 

Process/Laboratory Capacity.

Commenter Name: Barbara Schulze 

Commenter Organization: Merck 

Letter ID: 0064 

Comment ID: 31674 

Comment Code: 41000

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: The laboratory approval process proposed for the UCMR3 is rigorous and is necessary 

to assure that data generated by the study suitable for assessing the presence of hormones in 

drinking water. 

The laboratory approval process for participants in UCMR3 (76 Fed. Reg. 11720) is suitably rigorous 

to assure that only laboratories that can achieve the QA/QC requirements of Method 539 are 

accepted. The inclusion of proficiency testing (PT) for qualification is also important.

EPA should include analysis of proficiency test samples to complement laboratory audits during the 

2013-2015 monitoring period. 

EPA plans on conducting laboratory audits throughout the ongoing testing program (76 Fed. Reg. 

11721). Satisfactory audit results will be required in order for a laboratory to maintain approval for 

participation. However, the analysis of PT samples will only occur before the monitoring program 

begins. Merck recommends that participating laboratories be required to analyze at least one PT 

sample during the monitoring program. The results of this analysis should not necessarily be used to 

disqualify a laboratory as long as they have had a satisfactory audit. However, the results of this 

ongoing use of PT samples will serve as an additional check on the reliability of the monitoring data. 

Method 539 does not have any requirement that a laboratory analyze samples containing known 

amounts of the analytes that are prepared by an outside source and are therefore unknown to the 

analyst (PT samples). Requirements to test such samples are routine for laboratories in all of EPA's 

Office of Water programs and should be included in UCMR3. 

Summary

Merck supports the approach that EPA has developed to implement UCMR3. We appreciate EPA's 

consideration of these comments and particularly recommend that EPA emphasize the natural 

sources of most of the target hormones when it describes the sources of such chemicals in drinking 

water supplies. Merck works with other stakeholders to develop new methodologies to evaluate the 
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presence, fate and potential human health effects of APIs in surface and ground waters and will 

continue to share this information with EPA. 

We appreciate the opportunity to offer these comments. If you have any questions about these 

comments, please contact Mary Buzby at 908-423-7837.

Sincerely,

Barbara Schulze Director, Global Environmental Programs 

Response: Please see the response to comment code 41000 Laboratory Approval 

Process/Laboratory Capacity.

Commenter Name: Neil Parke 

Commenter Organization: Eli Lilly and Company 

Letter ID: 0076 

Comment ID: 31697 

Comment Code: 41000

Other EPA Comment Codes and Descriptions: 31010 EPA Method 539 - Hormones 

Comment: 5. The laboratory approval process proposed for the UCMR 3 is rigorous and is 

necessary to assure that data generated by the study suitable for assessing the presence of hormones 

in drinking water. 

The laboratory approval process for participants in UCMR 3 (76 Fed. Reg. 11720) is suitably 

rigorous to assure that only laboratories that can achieve the QA/QC requirements of Method 539 

are accepted. The inclusion of proficiency testing (PT) for qualification is also important. 

6. EPA should include analysis of proficiency test samples to complement laboratory audits during 

the 2013-2015 monitoring period. 

EPA plans on conducting laboratory audits throughout the ongoing testing program (76 Fed. Reg. 

11721). Satisfactory audit results will be required in order for a laboratory to maintain approval for 

participation. However, the analysis of PT samples will only occur before the monitoring program 

begins. Lilly recommends that participating laboratories be required to analyze at least one PT 

sample during the monitoring program. The results of this analysis should not necessarily be used to 

disqualify a laboratory if they have a satisfactory audit. However, the results of this ongoing use of 

PT samples will serve as an additional check on the reliability of the monitoring data. Method 539 

does not have any requirement that a laboratory analyze samples containing known amounts of the 

analytes that are prepared by an outside source and are therefore unknown to the analyst (PT 

samples). Requirements to test such samples are routine for laboratories in all of EPA’s Office of 

Water programs and should be included in UCMR 3.

Response: Please see the response to comment code 41000 Laboratory Approval 

Process/Laboratory Capacity.
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Commenter Name: Andrew Eaton 

Commenter Organization: MWH Laboratories 

Letter ID: 0047 

Comment ID: 31748 

Comment Code: 41000

Comment: 11. As a general policy on field blanks (regardless of method) we believe that it would be 

more cost effective, yet still provide reliable data, if the guidance was revised. If a hit in the sample 

was >10X the value in a positive field blank, the result should be considered valid, instead of 

automatically rejecting all positive data with a field blank result >1/3 of the MRL. This is consistent 

with guidance that has been used in other EPA monitoring programs. Again this could be left to the 

discretion of the utility whether to resample (and incur further costs) if a potential false positive was 

suspected (perhaps when it was the first case of a detect) or accept the result as is. Our experience 

with PFCs in groundwater is that repeat samples for positives at significant levels ( ie. . >0.05 ug/L) 

are reproducible. We have not seen significant issues with positive field blanks.

Response: Please see the response to comment code 41000 Laboratory Approval 

Process/Laboratory Capacity.
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Comment Code: 60000 Interrelationship of CCL, UCMR, NCOD and RegDet 

Summary Response to Comments on Interrelationship of CCL, UCMR, NCOD and 

RegDet: A stakeholder meeting specific to UCMR 3 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 the docket for presentation materials and meeting notes). The 

presentations also addressed the relationship between CCL, UCMR, NCOD, and the Regulatory 

Determination process. EPA continues to refine these relationships with each new round of 

evaluation, determination, and monitoring; and EPA will continue to invite stakeholder comments 

on any necessary improvements.

Individual Comments

Commenter Name: David Lipsky 

Commenter Organization: New York City Department of Environmental Protection (DEP) 

Letter ID: 0096 

Comment ID: 31790 

Comment Code: 60000

Comment: I’ve attached comments from the New York City Department of Environmental

Protection Agency concerning UCMR3 and Docket ID No. OW-2009-0090. DEP recognizes and 

apologizes for the fact that these comments are being submitted after the close of the official 

comment period which ended on May 2nd, 2011. We are submitting them, nonetheless, in the hope 

that these comments will be considered and evaluated by EPA in finalizing the revisions to the 

UCMR monitoring program. 

Dr. David Lipsky, Q.E.P. | Chief | NYC Environmental Protection Bureau of Water Supply, 

Distribution Water Quality Science & Research (O) 718 595 5340 | (M) 347 421 4929 | 

dlipsky@dep.nyc.gov 

May 5, 2011 Water Docket United States Environmental Protection Agency Mail Code 282211 T 

1200 Pennsylvania Avenue, NW. Washington, DC 20460 Attention: Docket ID No. OW-2009-

0090 

Dear Sir or Madam: 

The New York City Department of Environmental Protection ("DEP"), which is responsible for 

operating New York City's Public Water Supply System, greatly appreciates this opportunity to 

comment on the proposed revisions to the Unregulated Contaminant Monitoring Regulation 

("UCMR-3") for Public Water Systems.
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A. Proposed List of Constituents (76 FR 11716) 

DEP believes that, in general, there should be a close connection between the proposed UCMR 

analytes and the Contaminant Candidate List ("CCL") analytes. This linkage is necessary to ensure 

that there is a sound rationale for selecting analytes for monitoring, based on potential occurrence at 

levels of potential health significance, and that there are analytical methods available for reliably 

detecting the UCMR list analytes at levels of potential health significance. For the most part, DEP 

believes that the UCMR-3 list is an acceptable list, though some of the constituents, such as 

testosterone, as part of the hormone panel, are not on the CCL-3.

Response: Please see response to comment codes 60000 Interrelationship of CCL, UCMR, NCOD 

and RegDet, and 30000 Potential UCMR 3 Contaminants. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080 

Comment ID: 32043 

Comment Code: 60000

Comment: 8. Including stakeholder engagement from the beginning stages of developing 

Contaminant Candidate List 4 (CCL4) and UCMR4 so that a robust set of analytical methods can be 

developed for the highest priority CCL4 contaminants. 

AWWA appreciates the Agency’s openness to stakeholder input. We look forward to additional 

opportunities to refine the details of UCMR3 implementation as EPA moves forward to initiate the 

third monitoring cycle. Attached are more detailed comments on the issues identified above and 

other aspects of the proposal. If you have any questions regarding the attached comments please 

contact Steve Via at (202) 326-6130. Best regards,

Thomas W. Curtis Deputy Executive Director

cc: Cynthia Dougherty, EPA/OGWDW Greg Carroll, EPA/OGWDW/OST

Attachment

Response: Please see response to comment codes 60000 Interrelationship of CCL, UCMR, NCOD 

and RegDet, and 30000 Potential UCMR 3 Contaminants. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080 

Comment ID: 32049 

Comment Code: 60000

Comment: Developing Future UCMRs EPA has the responsibility to select as many as 30 analytes 

based on known/reasonably anticipated health risks and data gaps to make regulatory 
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determinations for as yet unregulated contaminants. EPA needs a broad outreach program to make 

sure the 30 it selects are the most credible opportunities for risk reduction. This outreach should 

occur in a transparent manner and EPA should clearly document contaminant outreach and the 

input obtained. A better prioritization process is needed for future UCMRs to fill occurrence data 

gaps for the most toxic contaminants that are most likely to occur in drinking water at levels of 

potential concern. An immediate example where interaction now would strengthen a future UCMR 

proposal is in development and testing of analytical methods for the most potentially toxic and 

abundant contaminants on CCL3, so that robust methods are available prior to proposal. 

AWWA is ready to work with EPA and other stakeholder to help select future UCMR analytes so 

that those selected provide the greatest public health protection to the public we serve.

Response: Please see response to comment codes 60000 Interrelationship of CCL, UCMR, NCOD 

and RegDet, and 30000 Potential UCMR 3 Contaminants. 
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Comment Code: 70000 Cost Estimates/ICR 

Summary Response to Comments on Cost Estimates/ICR: Based on public comment, and 

because of changes to the targeted list of Assessment Monitoring contaminants, EPA revised the 

laboratory fee estimates to update those presented with the proposed rule. In addition, EPA has 

moved the hormone monitoring requirement from Assessment Monitoring (List 1) to Screening 

Survey (List 2). This change substantially reduces the number of PWSs that are required to monitor 

for hormones, and thus, cost estimates were revised to reflect this change.

Estimates of laboratory fees are based on consultations with national drinking water laboratories and 

a review of the costs of similar analytical methods. EPA requested pricing estimates for UCMR 3 

methods from four national drinking water laboratories (these laboratories varied in size and 

experience, to ensure a representative set of cost estimates). Estimates were requested for all 

chemical methods that will be required under Assessment Monitoring, including: 200.8 (metals and 

total chromium); 218.7 (chromium-6); 300.1 (chlorate); 522 (1,4-dioxane); 524.3 (VOCs); 537 

(PFCs); and 539 (hormones). EPA averaged the pricing estimates from the laboratories that were 

consulted into the cost estimates. As part of these updated pricing estimates, laboratories accounted 

for all QA and field blank requirements. In addition, three laboratories provided estimated costs for 

the Pre-Screening Testing of viruses and related pathogen indicators. These costs were also averaged 

and incorporated into the cost estimates. 

With respect to per system burden estimates, EPA notes that all burden 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 sampling points that 

would then have greater sampling activity labor burden. Moreover, a system's burden is primarily 

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

2015). 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 annual average over the applicable threeyear ICR period (2012 - 2014).

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

of the relative smaller size of their infrastructure, but also because these systems will receive a great

deal of direct assistance from EPA and/or their State (e.g., EPA will collect the samples for the PreScreen Testing).

Some public commenters suggested that EPA underestimated PWS burden. In response to these 

comments, EPA reviewed the UCMR burden estimates against burden estimates used in recently 

published drinking water rules. In all aspects of burden assumptions (e.g., time allotted for reading 

rule requirements, sampling, reporting, etc.), the UCMR estimates were on par with, or more 

conservative (higher) than estimates made for other drinking water regulations.

In addition, regarding comments concerned with the expense of UCMR to large public water 

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

approval, conduct monitoring at representative entry point(s) 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 
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update this information. Moreover, for PWSs with multiple intakes from a single wholesaler, EPA 

has clarified in §141.40(a)(3) Table 1, footnote c, by specifying that a PWS may select a 

representative intake from a given wholesaler. EPA is available to advise PWSs regarding their 

choice of the most appropriate sampling site, based on their purchasing situation. The use of 

representative entry points and intakes will result in fewer samples and thus time and cost savings to 

the PWS. Based on the experience of UCMR 1 and UCMR 2, EPA believes that it is more 

appropriate to measure at each purchasing system to more accurately assess exposure. This approach 

helps ensure that the monitoring results reflect any potential water quality changes between the 

wholesaler and each purchasing system.

Individual Comments

Commenter Name: 

Commenter Organization: Northern Kentucky Water District 

Letter ID: 0060 

Comment ID: 31650 

Comment Code: 70000

Comment: With regards to the relative cost analysis, the burden and cost estimates may appear low. 

However, for a Utility such as the Northern Kentucky Water District with 3 treatment plants, our 

analysis cost for each plant shows that the quarterly cost alone could easily be more than the $5640 

estimated cost for the entire monitoring period. We urge the EPA to contact utilities to get a more 

accurate estimate of the cost to complete the required sampling and testing for the monitoring 

period. Additionally, we ask the EPA to consider the current state of the economy and the burden 

that existing regulations already place on utilities as these revisions are finalized. The data collected 

from the UCMR3 is very important but it is extremely important to keep in mind the financial 

impact on the utility when determining required sample locations for each contaminant. Would the 

data acquired be as effective if a utility, with 3 treatment plants or 3 wells from the same 

geographical location, only be required to collect one complete set of samples from one of the 

plants or wells? The utility cost could be reduced by one third. 

In conclusion, we hope that the EPA will take these issues into consideration as we keep the same 

goal in mind, protecting the public health by providing clean, safe drinking water. We appreciate the 

chance to be able to comment on this proposed regulation. We also thank you for your time. 

Sincerely,

Richard Harrison, PE Vice President of Engineering, Water Quality & Production Phone: 859-578-

5458 Email Address: rharr@nkywater.org 

Response: Please see response to comment code 70000 Cost Estimates/ICR.

Commenter Name: Diane VanDe Hei 

Commenter Organization: Association of Metropolitan Water Agencies (AMWA) 

Letter ID: 0070 

Comment ID: 31781 

Comment Code: 70000
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Comment: 15. Sample set costs, labor costs and total burden for large systems 

EPA’s proposal estimates the costs at $1320 per sample set, labor costs at $295/hour and 7.7 hours 

(for a total labor cost of $2271.50) and a total burden for very large systems at $5640 for analytical 

costs. This cost assumes only one sample site per utility. Many large utilities have more than one 

treatment plant, therefore the cost will often be much higher. 

EPA consistently underestimates the time burden and costs to utilities. AMWA requests that EPA 

better quantify the costs and provide supporting information for the cost estimates in the final rule 

with a hyperlink or detailed information as to where to find the final cost estimates for the rule. 

Two issues that EPA has not adequately accounted for in the cost estimates are the higher costs for 

laboratory QA/QC for these advanced methods and the cost of a field blank method for methods 

with low quantification levels, such as EPA Method 537. As these are specialized methods at very 

low reporting levels, most water systems will be dependent on commercial laboratories that receive 

EPA approval for the various methods. 

Response: Please see response to comment code 70000 Cost Estimates/ICR.

Commenter Name: David Lipsky 

Commenter Organization: New York City Department of Environmental Protection (DEP) 

Letter ID: 0096 

Comment ID: 31801 

Comment Code: 70000

Comment: G. Cost of the Proposed Action (76 FR 11724) 

DEP believes that EPA has underestimated the cost of rule implementation for very large systems. 

While the unit costs for analytical services appear reasonable, DEP believes that EPA has 

underestimated or not included the number of units that might be required per site if a rigorous 

QAQC program is initiated. Given the proposed methods and low MRLs, the number of QC 

samples should be a lot greater than a typical sampling campaign for SDWA regulated constituents. 

The average labor burden for very large systems is given as 6.3 hours which seems a substantive 

underestimate of burden. The monitoring burden is given as 0.5 hours per sampling point to collect 

and ship samples, etc. and about 6 hours for reporting. This seems to ignore the need to reprogram 

and train staff on specific sampling requirements, to revise SOPs and other instructions, to manage 

the new data, and to provide appropriate data review of sample results. It also ignores travel times to 

sample collection points, data management and other factors. EPA needs to do a better job, and 

provide more complete information on the basis for estimating the burden for rule implementation. 

H. Information Collection Request for UCMR-3-September 2010 (p. 39) 

In reviewing the basis for the estimated laboratory costs, DEP noticed an error in the assessment 

monitoring list, which lists the test for the 6 PFCs as an ICP/MS test at a cost of$391.67. This 

should be listed as an LC/MS/MS method, though the unit cost seems reasonable. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

70000 Cost Estimates/ICR Page 393 of 401

Sincerely, David Lipsky, Ph.D. Chief, Distribution Water Quality Science and Research 

Response: Please see response to comment code 70000 Cost Estimates/ICR.

Listing the analytical method for the PFCs as ICP/MS was a typographical error. That has been 

corrected.

Commenter Name: Mark R. Vickery, P.G. 

Commenter Organization: Texas Commission on Environmental Quality (TCEQ) 

Letter ID: 0087 

Comment ID: 31818 

Comment Code: 70000

Comment: Hello - 

Attached please find the Texas Commission on Environmental Quality's comments regarding 

Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR3) for Public Water 

Systems.

If you have any problems with the attachment format or this electronic transmission, or if you have 

questions or concerns about the comments, please contact me by return e-mail or by phone at (512) 

239-3786.

TCEQ appreciates the opportunity to comment on this issue. 

Thank you, Tangela

Tangela Niemann Texas Commission on Environmental Quality Intergovernmental Relations, MC119 Ofc 512.239.3786 Fax 512.239.3335 tangela.niemann@tceq.texas.gov Please consider whether it 

is necessary to print this e-mail

Water Docket U.s. Environmental Protection Agency Mail Code 282211T 1200 Pennsylvania 

Avenue NW Washington, DC 20460 Attn: Docket ID No. OW-2009-0090 May 2, 2011 Re: 

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

Systems

Dear Sir or Madam:

Thank you for the opportunitY to comment on the proposed Revisions of the UCMR 3 as 

published in the March 3, 2011, Federal Register with a comment period ending May 2, 2011. As the 

agency with delegated authority to assist EPA in the implementation of this standard, the Texas 

Commission on Environmental Quality is concerned with the costs of compliance associated with 

this expanded regulation and offers the attached comments.

Thank you for the opportunity to comment on the proposed rules. If you have questions regarding 

these comments, please contact Mr. Elston Johnson, Public Drinking Water Section, Office of 

Water, at (512) 239-4691 or elston.johnson@tceg.texas.gov. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

70000 Cost Estimates/ICR Page 394 of 401

Sincerely, Mark R. Vickery, P.G. Executive Director

Response: Please see response to comment code 70000 Cost Estimates/ICR.

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080 

Comment ID: 32103 

Comment Code: 70000

Comment: 14.Agency’s need for [UCMR3 data], the accuracy of the provided burden estimates, and 

any suggested methods for minimizing respondent burden. 

UCMR is an important element of SDWA regulatory structure. AWWA supports SDWA and the 

UCMR process. AWWA encourages EPA to continue to seek ways to make the UCMR data 

collection and data submittal processes cost- effective in terms of laboratory and water system 

personnel time while ensuring standards for data quality assurance. 

Response: Please see response to comment code 70000 Cost Estimates/ICR.
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

80000 Environmental Justice Approach Page 395 of 401

Comment Code: 80000 Environmental Justice Approach 

Summary Response to Comments on Environmental Justice Approach: 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. After considering 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 all 

customers served by the PWS. These reporting specifications are now established in §§141.35(c)(1) 

and (d)(3), for large and small systems, respectively. EPA believes that customer zip codes will 

provide EPA with useful information for future occurrence analyses.

Individual Comments

Commenter Name: Diane VanDe Hei 

Commenter Organization: Association of Metropolitan Water Agencies (AMWA) 

Letter ID: 0070 

Comment ID: 31782 

Comment Code: 80000

Comment: 16. Environmental Justice

AMWA agrees with EPA’s determination that the proposed UCMR will not have disproportionately 

high and adverse human health or environmental effects on minority or low-income populations for 

systems serving more than 10,000 persons in particular because by "seeking to identify unregulated 

contaminants that may pose health risks via drinking water from all PWSs" [that serve more than

10,000], "UCMR furthers the protection of public health for all citizens, including minority and 

lowincome populations using public water supplies." 

For similar reasons as described under Comment 3, above, AMWA does not agree that including zip 

codes to help inform a population demographic is an appropriate way to determine impacts of 

future drinking water regulations that may be proposed as a result of the UCMR regulation. In 

general, it is the water systems that serve a targeted, smaller population (i.e., less than 10,000) in

economically disadvantaged communities that may require additional assessment for environmental 

justice concerns rather than the larger systems that are covered by this regulation. 

Response: Please see response to comment code 80000 Environmental Justice Approach.

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0080 

Comment ID: 32105 

Comment Code: 80000
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

80000 Environmental Justice Approach Page 396 of 401

Comment: 16.EPA is soliciting comment on additional actions the Agency could take to further 

address environmental justice within the UCMR program. EPA requests stakeholder input on 

additional reporting elements to consider to support the Agency’s assessment of the monitoring 

results. EPA also requests comments regarding sampling and/or modeling approaches, and the 

feasibility and utility of applying these approaches, to determine disproportionate impacts on 

drinking water quality at PWSs serving minority and low-income populations. 

The purpose of UCMR is to collect nationally representative data to serve as a basis for national 

regulatory decision making including cost-benefit analysis. The clear nexus between this task and 

environmental justice (EJ) is with the small system sample which EPA funds directly. While UCMR3 

as proposed is a census of all systems serving more than 10,000 persons, the sample of smaller

systems is quite small relative to the number of small water systems in the United States. This 

discrepancy is important in that small, economically disadvantaged communities, particularly such 

communities made up primarily of people of color are underrepresented by the dataset resulting 

from UCMR3. Moreover, subsequent regulatory decision making will extrapolate from the UCMR3 

dataset to estimate the costs and benefits of national regulation. National drinking water standards 

based on this dataset will not adequately capture data representing very small water systems, 

including such systems that serve EJ communities, with respect to:

1. Observed occurrence (e.g., mean and median values),

2. The distribution of occurrence (e.g., variability as a function of water system size, location, etc.), 

and 

3. Disinfection practice (potentially important to understanding differences in chlorate occurrence 

compared to large system data).

Response: Please see response to comment code 80000 Environmental Justice Approach. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

90000 Comments Outside the Scope of UCMR 3 Page 397 of 401

Comment Code: 90000 Comments Outside the Scope of UCMR 3

Individual Comments

Commenter Name: M. Wright 

Commenter Organization:

Letter ID: 0044 

Comment ID: 31605 

Comment Code: 90000

Comment: Since flourides are toxic chemicals which cause bone embrittlement & do nothing to 

alleviate dental caries they should not be added to drinking water. This is enforced medication. Our 

water is being poisoned in the name of dental health. 

Response: This comment is outside scope of the UCMR 3 regulation. 
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

Appendix 1 Page 398 of 401

Appendix 1 – Complete List of EPA Comment Codes

Comment 

Code Comment Topics Comment Code Used?

10000 General Comments Yes

11000 Contaminant Candidate List (CCL) No

12000 Regulatory Determination No

20000 Sampling Design and Reporting Yes

21000 Assessment Monitoring Yes

22000 Pre-Screen Testing Yes

23000 Other Changes between UCMR 2 and UCMR 3 Yes

23100 Transient Systems Yes

23200 Retail Population Based Applicability Yes

23300 Ground Water Representative Monitoring Locations Yes

23400 Sampling Requirements Frequency Yes

23500 Revised Data Element #4 - Zip Codes Yes

23600 Revised Data Element #6 - Disinfectant Type Yes

23700 Other Data Elements No

23800 Revised Reporting Time Frames Yes

23810 Laboratory Reporting Time Yes

23820 PWS Review Time Yes

24000 Reporting System/SDWARS Yes

30000 Potential UCMR 3 Contaminants Yes

31000 Hormones Yes

31010 EPA Method 539 – Hormones Yes

31020 Other Methods – Hormones No

31030 Sampling Location – Hormones No

31040 Health Advisory – Hormones No

31050 Health Effects – Hormones Yes

31100 17-β-Estradiol No

31200 17-α-Ethynylestradiol No

31300 Estriol No

31400 Equilin No

31500 Estrone No

31600 Testosterone Yes

31700 4-Androstene-3,17-dione No

32000 Volatile Organic Compounds (VOCs) Yes
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

Appendix 1 Page 399 of 401

Comment 

Code Comment Topics Comment Code Used?

32010 EPA Method 524.3 – VOCs Yes

32020 Other Methods – VOCs Yes

32030 Sampling Location – VOCs No

32040 Health Advisory – VOCs No

32100 1,2,3-Trichloropropane Yes

32200 1,3-Butadiene Yes

32300 Chloromethane (methyl chloride) No

32400 1,1-Dichloroethane Yes

32500 n-Propylbenzene No

32600 Bromomethane (methyl bromide) No

32700 sec-Butylbenzene No

32800 Chlorodifluoromethane (HCFC-22) Yes

32900 Bromochloromethane (Halon 1011) No

33000 Synthetic Organic Compounds (SOCs) No

33010 EPA Method 522 - 1,4-Dioxane Yes

33020 Other Methods - 1,4-Dioxane No

33030 Sampling Location - 1,4-Dioxane No

33040 Health Advisory - 1,4-Dioxane No

33100 1,4-Dioxane Yes

34000 Metals Yes

34010 EPA Method 200.8 Rev 5.4 – Metals Yes

34020 ASTM D5673-10 – Metals No

34030 SM 3125 (1997) – Metals Yes

34040 Other Methods – Metals Yes

34050 Sampling Location – Metals Yes

34060 Health Advisory – Metals No

34070 Health Effects – Metals Yes

34100 Vanadium Yes

34200 Molybdenum Yes

34300 Cobalt Yes

34400 Strontium No

35000 Oxyhalide Anion No

35010 EPA Method 300.1 – Chlorate Yes

35020 ASTM D6581-08 – Chlorate No

35030 SM 4110D (1997) – Chlorate Yes
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

Appendix 1 Page 400 of 401

Comment 

Code Comment Topics Comment Code Used?

35040 Other Methods – Chlorate Yes

35050 Sampling Location – Chlorate Yes

35060 Health Advisory – Chlorate No

35100 Chlorate Yes

36000 Perfluorinated Compound (PFCs) Yes

36010 EPA Method 537 Rev 1.1 – PFCs Yes

36020 Other Methods – PFCs Yes

36030 Sampling Location – PFCs No

36040 Health Advisory – PFCs No

36050 Health Effects – PFCs Yes

36100 Perfluorooctane sulfonic acid (PFOS) Yes

36200 Perfluorooctanoic acid (PFOA) Yes

36300 Perfluorononanoic acid (PFNA) No

36400 Perfluorohexane sulfonic acid (PFHxS) No

36500 perfluoroheptanoic acid (PFHpA) No

36600 Perfluorobutanesulfonic acid (PFBS) Yes

37000 Viruses Yes

37010 EPA Method 1615 – Viruses Yes

37020 Other Methods – Viruses No

37030 Sampling Location – Viruses Yes

37035 Sampling Methodology – Viruses Yes

37040 Health Advisory – Viruses No

37050 Borchardt Data – Viruses Yes

37100 Norovirus No

37200 Enteroviruses No

37300 General Indicators No

37310 Sampling Methodology (Indicators) No

37400 Aerobic EndoSpores Yes

37410 SM 9218 - Aerobic EndoSpores No

37420 Other Methods - Aerobic EndoSpores No

37500 Bacteriophages No

37510 EPA Method 1601 – Bacteriophages No

37520 EPA Method 1602 – Bacteriophages No

37530 Other Methods – Bacteriophages No

37600 Enterococci No
EPA-OGWDW Final UCMR 3 Response to Comments EPA 815-R-11-004

January 2012

Appendix 1 Page 401 of 401

Comment 

Code Comment Topics Comment Code Used?

37610 EPA Method 1600 – Enterococci No

37620 Enterolert – Enterococci No

37630 Other Methods – Enterococci No

37700 Total Coliform No

37710 EPA Method 1604 - Total Coliform No

37720 Other Methods - Total Coliform No

37800 E. coli No

37810 EPA Method 1604 – E. coli No

37820 Other Methods – E. coli No

38000 Other Contaminants Yes

38100 Chromium-6 Yes

38110 EPA Method 218.7 – Chromium-6 Yes

38120 Other Methods – Chromium-6 Yes

38130 Sampling Location – Chromium-6 Yes

38140 Health Advisory – Chromium-6 No

38200 Total Chromium Yes

38210 EPA Method 200.8 Rev 5.4 - Total Chromium Yes

38220 ASTM D5673-10 - Total Chromium No

38230 SM 3125 (1997) - Total Chromium No

38240 Other Methods - Total Chromium No

38250 Sampling Location - Total Chromium Yes

38260 Health Advisory - Total Chromium No

40000 Minimum Reporting Level Determination/LCMRLs Yes

41000 Laboratory Approval Process/Laboratory Capacity Yes

50000 States' Role in the UCMR Program No

60000 Interrelationship of CCL, UCMR, NCOD and RegDet Yes

70000 Cost Estimates/ICR Yes

71000 Impact on Small Systems No

80000 Environmental Justice Approach Yes

90000 Comments Outside the Scope of UCMR 3 Yes