Responses to Public 

Comments on 

Preliminary 

Regulatory 

Determinations for 

Contaminants on the 

Third Drinking Water 

Contaminant 

Candidate List
Office of Water (4607M)

EPA 810-R-15-001

December 2015
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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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.................................................................................... 2

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

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

2. Comments and EPA Responses by Comment Code ......................................................................... 3

Comment Code: 10000 General comments about regulatory determinations..................................................... 3

Comment Code: 13000 RD 3 Protocol (three phase process to narrow down the list of CCL 3 

contaminants)................................................................................................................................................... 6

Comment Code: 15000 RD 3 communications and outreach................................................................................ 8

Comment Code: 21000 Evaluation of adverse health effects (first criterion)....................................................12

Comment Code: 22000 Evaluation of contaminant occurrence (second criterion)..........................................13

Comment Code: 24000 Evaluation of costs and benefits .....................................................................................14

Comment Code: 30500 Preliminary determination not to regulate dimethoate, 1,3-dinitrobenzene, terbufos, 

and terbufos sulfone .....................................................................................................................................22

Comment Code: 33000 Preliminary determination to regulate strontium..........................................................25

Comment Code: 33150 Relative source contribution for strontium ...................................................................35

Comment Code: 33200 Health effects of strontium (first criterion)...................................................................37

Comment Code: 33300 Occurrence of strontium (second criterion)..................................................................41

Comment Code: 33400 Meaningful opportunity for health risk reduction for strontium (third criterion) ..46

Comment Code: 33500 Costs and benefits of regulating strontium....................................................................46

Comment Code: 40000 EPA's decision to postpone determinations for nitrosamines (NDBA, NDEA, 

NDMA, NDPA, NMEA, NPYR) and chlorate.......................................................................................49

Comment Code: 41000 Nitrosamines.......................................................................................................................52

Comment Code: 41150 Relative source contribution for nitrosamines..............................................................53

Comment Code: 41400 Meaningful opportunity for health risk reduction for nitrosamines (third criterion)

..........................................................................................................................................................................54

Comment Code: 42150 Relative source contribution for chlorate ......................................................................54

Comment Code: 42300 Occurrence of chlorate (second criterion).....................................................................55

Comment Code: 50000 Other contaminants...........................................................................................................56

Comment Code: 70000 Comments outside the scope of RD 3...........................................................................61

Appendix 1 – Complete List of EPA Comment Codes........................................................................ 65
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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List of Exhibits

Exhibit 1: Public Submissions by Commenter Type....................................................................................2
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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1. Introduction and Overview

Background

The 1996 Safe Drinking Water Act (SDWA) Amendments (section 1412(b)(1)) require EPA to 

publish the Contaminant Candidate List (CCL) every five years. The CCL is a list of contaminants 

that are not subject to any proposed or promulgated national primary drinking water regulations 

(NPDWRs), are known or anticipated to occur in public water systems (PWSs) and may require 

regulation under the SDWA. The 1996 SDWA Amendments also direct the agency determine

whether to regulate at least five contaminants from the CCL every five years. SDWA requires the 

agency to publish a Maximum Contaminant Level Goal (MCLG) and promulgate an NPDWR for a 

contaminant if the Administrator determines that:

(a) the contaminant may have an adverse effect on the health of persons;

(b) the contaminant is known to occur or there is substantial likelihood that the contaminant 

will occur in PWSs with a frequency and at levels of public health concern; and

(c) in the sole judgment of the Administrator, regulation of such contaminant presents a 

meaningful opportunity for health risk reduction for persons served by PWSs.

If EPA determines that all three of these statutory criteria are met, it makes a preliminary positive 

regulatory determination that an NPDWR is needed. Following a comment response period, if a 

final positive regulatory determination is made the agency has 24 months to publish a proposed 

Maximum Contaminant Level Goal (MCLG) and an NPDWR. After the proposal, the agency has 

18 months to publish a final MCLG and promulgate a final NPDWR (SDWA section 

1412(b)(1)(E)). The agency may determine that there is no need for a regulation when a contaminant 

fails to meet one or more of the criteria. A decision not to regulate is considered a final agency 

action and is subject to judicial review. The agency can choose to publish a Health Advisory (a nonregulatory action) or other guidance for any contaminant on the CCL, independent of the regulatory 

determination.

EPA published proposed regulatory determinations for five contaminants from the third CCL 

(1,3-dinitrobenzene, dimethoate, strontium, terbufos, and terbufos sulfone) on October 20, 2014 (79 

FR 62715) and requested public comment. EPA received fifteen public submissions (in the form of 

letters, e-mails, and/or postings to www.regulations.gov). All original public submissions can be 

found at www.regulations.gov, under Docket ID EPA-HQ-OW-2012-0155.

EPA’s Categorization of Public Comments and Document Organization

EPA sought public comment on a number of topics, including: the five preliminary determinations; 

the revised RfD calculation for strontium; additional information on public exposure to strontium 

via drinking water and other media; and additional health and occurrence information that may be

useful for the agency to consider as it evaluates other CCL contaminants, namely chlorate and 

nitrosamines, in the context of the regulatory review of existing microbial and disinfection byproduct (MDBP) rules. Anticipating the types of 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-OGWDW Regulatory Determinations 3 Response to Comments

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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 of this document presents the public comments and EPA’s responses. The comments and 

responses are organized first by EPA Comment Code, then 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, e-mail, 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 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 the 

reader to the associated Response to Comment Code.

Who Submitted Comments

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

stakeholders. Exhibit 1, below, lists commenter categories and the number of submissions received 

from each category.

Exhibit 1: Public Submissions by Commenter Type

Organization Number of Submissions1

Private Citizen/Anonymous 3

Industry Group 3

Drinking Water System 2

Drinking Water Organization 3

Environmental /Community Group 4

Total 15

1. Fifteen public submissions were received from fourteen commenters. One commenter in the Industry Group category 

offered two separate submissions.
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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2. Comments and EPA Responses by Comment Code

Comment Code: 10000 General comments about regulatory determinations 

EPA Response to Comment Code 10000: Commenters support the science-based Regulatory 

Determination process and some commenters support the preliminary determination to regulate 

strontium. Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

The agency will continue to use the best available science and information to evaluate contaminants 

as part of EPA’s regulatory determinations. For comments on activities outside the scope of the 

Third Regulatory Determination (RD 3) [i.e., Contaminant Candidate List (CCL), Unregulated 

Contaminant Monitoring Rule (UCMR)], please see comment code 70000 Comments outside the 

scope of RD 3. 

Individual Comments 

 

Commenter Name: Anonymous 

Commenter Organization: 

Letter ID: 0011 

Comment ID: 32156 

Comment Code: 10000 

Comment: Please fight against any chemicals or companies using our natural resources not healthy.

EPA Response: Please see response to comment code 10000 General comments about regulatory 

determinations. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32171 

Comment Code: 10000 

Comment: Ensuring that CCLs, UCMRs, and regulatory determinations provide a sound 

foundation for the regulatory development process is critical. Through the Water Industry Technical 

Action Fund (WITAF), AWWA has sponsored research on CCLs, UCMRs, and regulatory 

determinations that has resulted in the following four peer-reviewed publications: 

1. Rosen, J.S. and Roberson, J.A. A simplified approach to developing future contaminant candidate 

lists. Jour. AWWA, 99:3:66 (March 2007). 

2. Roberson, J.A., et al. Risk indexes for draft CCL3 chemicals. Jour. AWWA, 101:9:64 (September 

2009). 
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3. Roberson, J.A. Informing regulatory decisions using national occurrence data. Jour. AWWA, 

104:3:55 (March 2012).

4. Roberson, J.A. and Eaton, A. Retrospective analysis of mandated national occurrence monitoring 

and regulatory decisions. Jour. AWWA, 106:3:63 (March 2014). 

The four papers are included as appendices to these comments. A related paper on AWWA's 

recommendations for the Fourth Contaminant Candidate List (CCL4) is being finalized and will be 

submitted to Journal-AWWA shortly for peer review. 

AWWA encourages EPA to review these papers and to incorporate the data and information into 

the Agency's future decision-making on CCLs and regulatory determinations. The absence of these 

four published peer- reviewed papers in the reference section of the Federal Register notice is 

notable. Section 1412(b)(3) of the SDWA requires the use of the best available, peer-reviewed 

science in the Agency's decision-making. 

EPA Response: Thank you for sharing the papers related to CCLs, UCMRs, and regulatory 

determinations. Although they were not cited, EPA has reviewed the four papers and considered 

their input. Please see response to comment code 10000 General comments about regulatory 

determinations and comment code 70000 Comments outside the scope of RD 3. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32192 

Comment Code: 10000 

Comment: [Appendices 1. Rosen, J.S. and Roberson, J.A. A simplified approach to developing 

future contaminant candidate lists. Jour. AWWA, 99:3:66 (March 2007). 

2. Roberson, J.A., et al. Risk indexes for draft CCL3 chemicals. Jour. AWWA, 101:9:64 (September 

2009). 

3. Roberson, J.A. Informing regulatory decisions using national occurrence data. Jour. AWWA, 

104:3:55 (March 2012).

4. Roberson, J.A. and Eaton, A. Retrospective analysis of mandated national occurrence monitoring 

and regulatory decisions. Jour. AWWA, 106:3:63 (March 2014).] 

EPA Response: EPA has reviewed the four papers. Thank you for sharing them. Please see 

response to comment code 10000 General comments about regulatory determinations and comment 

code 70000 Comments outside the scope of RD 3. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Commenter Name: Anonymous 

Commenter Organization: 

Letter ID: 0023 

Comment ID: 32228 

Comment Code: 10000 

Comment: Good idea!

EPA Response: EPA notes the support for the preliminary determination. 

Commenter Name: James Taft 

Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 

Letter ID: 0026 

Comment ID: 32243 

Comment Code: 10000 

Comment: December 19, 2014 

Docket EPA-HQ-OW-2012-0155 Water Docket Environmental Protection Agency Mail Code: 

2822T 1200 Pennsylvania Ave., NW. Washington, DC 20460 

To Whom it May Concern: 

In response to the notice in the Federal Register of October 20, 2014 (79 FR 62715) the Association 

of State Drinking Water Administrators (ASDWA) is offering comments to the U.S. Environmental 

Protection Agency (EPA) on the Preliminary Regulatory Determinations on Contaminants on the 

Third Contaminant Candidate List. ASDWA is the professional Association that represents the 

collective interests of the drinking water programs in the states, territories, Navajo Nation, and 

District of Columbia responsible for implementation of the Safe Drinking Water Act (SDWA). The 

regulatory determinations, particularly the regulations eventually resulting from positive 

determinations, can significantly impact the future activity of state drinking water programs as they 

implement the SDWA. We therefore ask for your consideration of these comments in light of those 

potential impacts. 

ASDWA has always supported the regulatory process (CCL, UCMR, Regulatory Determination, 6 

year review) set forth in the 1996 amendments to the SDWA. It is a science-based process that 

makes regulatory determinations only after considering health effects, occurrence and determining 

that a regulation can improve public health protection. We believe that the process, when supported 

with adequate data, is vastly preferable to regulating based on arbitrary target numbers or focusing 

on contaminants with high media profiles but where regulation is not supported by reliable data. 

EPA Response: Please see response to comment code 10000 General comments about regulatory 

determinations. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Comment Code: 13000 RD 3 Protocol (three phase process to narrow down 

the list of CCL 3 contaminants) 

Individual Comments 

 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32201 

Comment Code: 13000 

Comment: * Concerns about unintended consequences of federal standards for naturally occurring 

elements

EPA Response: Please see response to comment ID 32207. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32207 

Comment Code: 13000 

Comment: Concerns about unintended consequences of federal standards for naturally occurring 

elements 

Any strontium standard will have a disproportionate impact on rural low- income households 

because: most communities out of compliance will be rural and small; rural communities tend to 

have lower median household incomes; and rural communities tend to have higher percentages of 

households living below poverty thresholds. As strontium is a naturally occurring element, does the 

Agency believe the public has a different or unique concept of public risk from naturally occurring 

elements versus anthropogenic chemicals/substances in their drinking water? Most all of the noncompliance in small and rural communities with federal maximum contaminant levels (MCLS) 

occurs for naturally occurring elements (strontium, fluoride, arsenic, uranium, radium, radon, etc.). 

Further, the Safe Drinking Water Act mandates that the Agency identifies enforceable drinking 

standards using a prescribed process that is neither primarily based on public health nor health 

effects science, but primarily on the feasibility of what a large city can afford. Under the mandated 

standard-setting scheme, the Agency is forced to set standards that can be very expensive for small 

communities and low-income populations. Sometimes the standard can be orders of magnitude less 

dangerous than the risk of breathing ambient/outdoor air. NRWA wants to ensure that the 

understanding of the public health risks of particular concentrations of naturally occurring elements 

in public drinking water are properly understood and applied in making public policy. We urge the 

Agency to consider whether the current policy for selecting naturally occurring contaminants, under 
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Section 1412(b)(1) of the Safe Drinking Water Act (SDWA), is appropriate or is in need of 

modification.

EPA Response: See response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action 

Letter ID: 0022 

Comment ID: 32227 

Comment Code: 13000 

Comment: Comments on Process, Supporting Information and Rationale 

The process for Regulatory Determination 3 is improved over prior processes. The Protocol for 

Regulatory Determinations 3 provides a more thorough and transparent framework within which to 

reach the determinations. The rationale for making the Determinations is also clear. An area for 

future consideration to enable better public understanding of the process and the analysis involved 

would be to clarify how a contaminant can move through the Contaminant Candidate List (CCL) 

process and into the Regulatory Determination process and then lack sufficient occurrence data in 

ambient and finished water to merit a positive Regulatory Determination. 

Thank you for the opportunity to comment on this Preliminary Determination. 

Lynn Thorp, National Campaigns Director, Clean Water Action 

202-895-0420 ext. 109; lthorp@cleanwater.org 1444 Eye Street NW; Suite 400 Washington DC 

20005

EPA Response: This comment supports the EPA’s view that its Regulatory Determination process 

is transparent and appropriately thorough. In addition, EPA will keep the commenters points made 

“for future consideration” in mind when conducting future regulatory determinations. At this time, 

the Agency notes that development of the CCL, regulatory determinations, and any subsequent 

rulemaking should be viewed as a progression where each process builds upon the previous process, 

including the collection of data and analyses conducted. The agency's improvements in developing 

CCL 3 provide an excellent foundation for RD 3 by enhancing EPA's ability to identify 

contaminants of concern for drinking water. As a contaminant proceeds from the Contaminant 

Candidate List to the Regulatory Determination process, and eventually, where applicable, the 

regulation development process, the data needs and analyses become more exacting. The agency is 

unable to make regulatory determinations for all CCL contaminants because some lack adequate 

health and/or occurrence data to evaluate the contaminant against the three statutory criteria. For 

additional information on the CCL and Regulatory Determination processes and background, 

including statutory requirements, see the discussion in section II.B of the Federal Register Notice for 

the preliminary regulatory determinations (79 FR 62716). 
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Comment Code: 15000 RD 3 communications and outreach 

EPA Response to Comment Code 15000: EPA’s view its Regulatory Determination process as 

appropriately transparent. Many commenters generally commended the Agency for its transparent 

Regulatory Determination process. Several commenters specifically expressed support for the 

Agency’s public outreach efforts during the development of today’s determination. The EPA notes 

that the Agency will continue in the future to seek external advice and expert opinion in the forms 

of public stakeholder meetings and public comments. 

The Office of Ground Water and Drinking Water plans to continue to communicate and collaborate 

with other parts of EPA's Office of Water and other EPA offices as part of the agency's Action 

Development Process. The agency will also continue to collaborate with other pertinent federal 

agencies conducting activities related to strontium that may further inform the agency process. In 

addition, the agency welcomes comments, data and information from the public. 

The process to develop a National Primary Drinking Water Regulation is a separate process with 

more detailed analyses. This process begins when a final determination is made to regulate a 

contaminant. The agency is required to publish a proposed regulation and allow opportunity for 

public comment within 24 months after making a final determination to regulate a contaminant. 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32164 

Comment Code: 15000 

Comment: December 16, 2014 

Water Docket Environmental Protection Agency Mailcode 28221T 1200 Pennsylvania Ave. NW 

Washington, DC 20460 

Re: Comments on Preliminary Third Regulatory Determinations Docket ID No. EPA-HQ-OW2012-0155

Dear Docket: 

The American Water Works Association (AWWA) would like to thank EPA's Office of Ground 

Water and Drinking Water (OGWDW) for the opportunity to comment on the October 20, 2014 

Federal Register notice (79 FR 62715) regarding the Preliminary Regulatory Determinations for 

Contaminants on the Third Drinking Water Contaminant Candidate List (CCL3). AWWA is an 

international, nonprofit, scientific and educational society dedicated to providing total water 

solutions assuring the effective management of water. Founded in 1881, the Association is the 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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largest organization of water supply professionals in the world. Our membership includes over 3,900 

utilities that supply roughly 80 percent of the nation's drinking water and treat almost half of the 

nation's wastewater. Our nearly 50,000 members represent the full spectrum of the water 

community: public water and wastewater systems, environmental advocates, scientists, academicians, 

and others who hold a genuine interest in water, our most important resource. AWWA unites the 

diverse water community to advance public health, safety, the economy, and the environment. 

AWWA commends EPA for the Agency's generally transparent approach to making regulatory 

determinations. The Federal Register notice provides clarity on the data and information used in the 

Agency's decisions. 

EPA Response: Please see response to comment code 15000 RD 3 communications and outreach. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32170 

Comment Code: 15000 

Comment: Comments by the American Water Works Association On the Preliminary Third 

Regulatory Determinations 

The American Water Works Association (AWWA) would like to thank EPA’s Office of Ground 

Water and Drinking Water (OGWDW) for the opportunity to comment on the October 20, 2014 

Federal Register notice (79 FR 62715) regarding the Preliminary Regulatory Determinations for 

Contaminants on the Third Drinking Water Contaminant Candidate List (CCL3). AWWA is an 

international, nonprofit, scientific and educational society dedicated to providing total water 

solutions assuring the effective management of water. Founded in 1881, the Association is the 

largest organization of water supply professionals in the world. Our membership includes over 3,900 

utilities that supply roughly 80 percent of the nation's drinking water and treat almost half of the 

nation’s wastewater. Our nearly 50,000 members represent the full spectrum of the water 

community: public water and wastewater systems, environmental advocates, scientists, academicians, 

and others who hold a genuine interest in water, our most important resource. AWWA unites the 

diverse water community to advance public health, safety, the economy, and the environment. 

AWWA commends EPA for the Agency’s generally transparent approach to making regulatory 

determinations. The Federal Register notice provides clarity on the data and information used in the 

Agency’s decisions. Making appropriate regulatory determinations, both positive and negative, is a 

critical part of the regulatory development process. AWWA and others in the drinking water 

community have played (and will continue to play) an active role in the identification of 

contaminants to list on the Contaminant Candidate Lists (CCLs), the development of Unregulated 

Contaminant Monitoring Rules (UCMRs) to fill occurrence data gaps, and the resultant regulatory 

determinations as required by Section 1412(b)(1) of the Safe Drinking Water Act (SDWA).

EPA Response: Please see response to comment code 15000 RD 3 communications and outreach. 
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Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32198 

Comment Code: 15000 

Comment: TO: Docket ID No. EPA-HQ-OW-2012-0155 Water Docket, EPA Docket Center, 

EPA West, Room 3334, 1301 Constitution Avenue NW, Washington, DC. FROM: National Rural 

Water Association CONTACT: Mike Keegan, Analyst DATE: December 19, 2014 SUBJECT: 

Preliminary Regulatory Determinations for Contaminants on the Third Drinking Water 

Contaminant Candidate List 

National Rural Water Association (NRWA) 

Headquartered in Duncan (Oklahoma), NRWA is the non-profit association of the federated state 

rural water associations with a combined membership of over 30,000 small and rural communities. 

NRWA is the country's largest water utility association and the largest community- based 

environmental organization. State Rural Water Associations are non-profit associations governed by 

board members elected from the membership. 

Our member utilities have the very important public responsibility of complying with all applicable 

U.S. Environmental Protection Agency (EPA) regulations and for supplying the public with safe 

drinking water and sanitation every second of every day. 

Most U.S. water utilities are small; 94% of the country's 51,651 drinking water supplies serve 

communities with fewer than 10,000 persons, and 80% of the country's 16,255 wastewater supplies 

serve fewer than 10,000 persons. Small and rural communities often have difficulty providing safe, 

affordable drinking water and sanitation due to limited economies of scale and lack of technical 

expertise. Similarly, when it comes to providing safe water and compliance with federal standards, 

small and rural communities have a difficult time due to their limited customer base. This is 

compounded by the fact that small and rural communities often have lower median household 

incomes and higher water rates compared to larger communities. As a result, the cost of compliance 

is often dramatically higher per household. 

Through our partnerships with the U.S. Department of Agriculture, EPA, and state agencies, 

NRWA provides on-site assistance and training to all small and rural communities. A typical on-site 

contact could include: ensuring the water service is protected and secure; explaining how a 

community can comply with federal or state regulations; discovering and repairing a faulty gas 

chlorination system; assisting a community to remove and replace the filtration media; training a new 

operator to run that particular treatment system; implementing a non-point pollution prevention 

plan; solving lead and copper rule problems; completing all the paperwork for the various water 

infrastructure funding programs, etc. 
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Rural and small communities want to ensure quality drinking water, wastewater treatment, and 

protect their local environment. After all, local water supplies are operated by people who are 

locally-elected and whose families drink the water every day. By our very nature, we strive to take 

every possible action to protect consumers (ourselves), our water resources and our natural 

environment. 

NRWA appreciates the EPA's Office of Ground Water and Drinking Water (OGWDW) for the 

opportunity to comment on the October 20, 2014 Federal Register notice (79 FR 62715) regarding 

the Preliminary Regulatory Determinations for Contaminants on the Third Drinking Water 

Contaminant Candidate List (CCL3). NRWA also appreciates and supports the Agency's outreach, 

public comment and stakeholder involvement opportunities.

EPA Response: Please see response to comment code 15000 RD 3 communications and outreach. 

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action 

Letter ID: 0022 

Comment ID: 32224 

Comment Code: 15000 

Comment: We recognize that this Regulatory Determination is the beginning of a multi-faceted 

process. We agree with EPA that field testing of treatment technologies will be a critical part of this 

process. We also urge the Office of Ground Water and Drinking Water to continue to communicate 

with other parts of EPA Office of Water, other EPA offices and other pertinent federal agencies 

where activities related to strontium may be ongoing. For example, strontium is associated with oil 

and gas wastewater, coal extraction and burning and other activities. To the extent that other laws 

and regulations can result in reduction of strontium contamination of drinking water sources, it is 

important for other parts of EPA and other agencies to recognize that the detailed analysis to set a 

NPDWR for strontium will now be underway.

EPA Response: Please see comment code 33000 Preliminary determination to regulate strontium. 

Commenter Name: James Taft 

Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 

Letter ID: 0026 

Comment ID: 32244 

Comment Code: 15000 

Comment: We also appreciate, and actively contribute to, the public participation opportunities at 

each stage of the regulatory process. Only through such an open and transparent process will 

regulations be developed that are justifiable.

EPA Response: Please see response to comment code 15000 RD 3 communications and outreach. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Commenter Name: James Taft 

Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 

Letter ID: 0026 

Comment ID: 32250 

Comment Code: 15000 

Comment: The Path Forward: 

ASDWA was pleased to provide input on these regulatory decisions and appreciates the Agency's 

consideration of our comments. In support of the final decisions, we are always ready to assist EPA 

in crafting the best regulations possible. As co-regulators with EPA, states have a vested interest in 

assuring that any resulting regulations are appropriate and can be effectively and efficiently 

implemented. To that end, ASDWA will be available at any time to help identify state participants in 

regulatory development activities and support other state input on future rules. 

Please contact me at 703-812-9507 or jtaft@asdwa.org if we can provide additional information or if 

any clarification of these comments is needed. 

Sincerely, 

James D. Taft Executive Director

EPA Response: Please see response to comment code 15000 RD 3 communications and outreach. 

Comment Code: 21000 Evaluation of adverse health effects (first criterion) 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32187 

Comment Code: 21000 

Comment: Age-Specific Adjustment in Risk Assessments 

EPA is now using an age-specific adjustment in computation of RfDs in some of its risk analyses. 

This approach seems reasonable, and this is probably the first time the age-specific exposure factors 

have been used at the start of the regulatory development process for national drinking water 

regulations. Due to potential precedent-setting of this adjustment in the development of future 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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regulations, the Agency must demonstrate that this is not a redundant factor that is already covered 

by the default factor of 10 for intraspecies variability.

EPA Response: The Age Dependent Adjustment Factors (ADAFs) are intended to characterize 

risk with most vulnerable populations and are not redundant with other conversion or safety factors 

which account for variability and uncertainty that are reflected in possible differences between test 

animals and humans and non-age related variability within the human population (i.e., 10 for 

intraspecies variability). For additional information, refer to section III.C.1 of the Federal Register 

Notice for the preliminary regulatory determination (79 FR 62716). 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32188 

Comment Code: 21000 

Comment: HRL and 1/2 HRL Values 

In numerous places in the Federal Register notice, the Health Reference Level (HRL) and 1/2 HRL 

are used to suggest tentative health based values and impacts. The HRL has not been finalized at this 

point and it should not be construed to be the likely MCLG. The HRL can be considered to be a 

tentative outerbound benchmark value, partly because it utilizes a default 20% RSC applied to the 

RfD factors as a screening tool. However, the ultimate RfD and MCLG will be determined after the 

proposal as part of the promulgation of the MCLG and MCL. This must be recognized and 

appropriate options should be analyzed and explained as part of that proposal. 

EPA Response: HRLs are risk derived concentrations against which to evaluate the occurrence 

data to determine if contaminants occur at levels of potential public health concern. HRLs are 

derived prior to the development of a complete exposure assessment. Please see response to 

comment code 33000 Preliminary determination to regulate strontium. 

Comment Code: 22000 Evaluation of contaminant occurrence (second 

criterion) 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32189 

Comment Code: 22000 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Comment: Mention of the 1/2 HRL at this point in the process has little relevance. The 1/2 HRL, 

or more importantly half of MCL, does have relevance at the time of proposal and promulgation. It 

or an analogous number would provide some indication of potential regulatory economic impact for 

one or more potential MCLs reflecting costs and feasibility, because where there is sufficient 

variability of strontium concentrations in source waters, communities that have concentrations 

somewhat below the MCL will likely need to take some action to avoid the potential for exceeding 

the regulation.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Comment Code: 24000 Evaluation of costs and benefits 

Individual Comments 

 

Commenter Name: Paul Cicio 

Commenter Organization: Industrial Energy Consumers of America 

Letter ID: 0015 

Comment ID: 32193 

Comment Code: 24000 

Comment: December 15, 2014 

Water Docket Environmental Protection Agency Mailcode:[28221T] 1200 Pennsylvania Avenue, 

NW Washington, DC 20460 

RE: Preliminary Regulatory Determinations for Contaminants on the Third Drinking Water 

Contaminant Candidate List, Docket ID No. EPA-HQ- OW-2012-0155

We are pleased to submit these comments on the U.S. Environmental Protection Agency's (EPA) 

notice of preliminary determination for constituents found in U.S. drinking water systems [FN1: 79 

FR 62716]. In this proposed determination, EPA determines that four constituents do not warrant 

national drinking water standards and one constituent, strontium, does. We are submitting 

comments on EPA's failure to estimate the social benefits and social costs in its analysis for the 

determination. Specifically, in its analysis for the determination, EPA failed to consider the 

additional energy usage and its externalities in this rulemaking. 

The Industrial Energy Consumers of America is a nonpartisan association of leading manufacturing 

companies with $1.0 trillion in annual sales, over 2,900 facilities nationwide, and with more than 1.4 

million employees worldwide. It is an organization created to promote the interests of 

manufacturing companies through advocacy and collaboration for which the availability, use and 

cost of energy, power or feedstock play a significant role in their ability to compete in domestic and 

world markets. IECA membership represents a diverse set of industries including: chemical, plastics, 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 15 of 67

steel, iron ore, aluminum, paper, food processing, fertilizer, insulation, glass, industrial gases, 

pharmaceutical, building products, brewing, independent oil refining, and cement. 

Under the Safe Drinking Water Act Amendments of 1996, EPA must make a regulatory 

determination every five years on at least five unregulated contaminants. A regulatory determination 

is a decision about whether or not to begin the process to propose and promulgate a national 

primary drinking water regulation (aka a maximum contaminant level MCL”) for an unregulated 

contaminant. These unregulated contaminants are chosen from the Contaminant Candidate List 

(CCL). The SDWA requires EPA to publish a new CCL every five years. 

In its determinations concerning the third CCL list (CCL3), the agency is making preliminary 

determinations to regulate one contaminant (i.e., strontium) and to not regulate four contaminants 

(i.e., 1,3- dinitrobenzene, dimethoate, terbufos and terbufos sulfone). 

If SCC is Used, OMB Should Require Uniform Application of SCC as a Potential Regulatory Cost 

Across Activities 

EPA is not alone in its inconsistent application of SCC as a potential regulatory cost. Federal 

agencies have inconsistent application of the SCC in their regulatory analyses. Few other agencies 

have acknowledged any potential energy/SCC externality in their rulemakings. If SCC is used, for it 

to fit with Circular A-4's requirements, both potential benefits and costs would need to be 

considered. 

Thank you for giving these points consideration. If you have any questions, or if we can be of 

further assistance, please feel free to contact me at (202) 223-1661.

Sincerely, 

Paul N. Cicio 

President

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32203 

Comment Code: 24000 

Comment: * Urge the Agency to correct the existing affordability policy before promulgating any 

additional National Public Drinking Water Regulations (NPDWRs)

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 16 of 67

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32209 

Comment Code: 24000 

Comment: Urge the Agency to correct the existing affordability policy before promulgating any 

additional National Public Drinking Water Regulations (NPDWRs) 

NRWA urges the Agency to update the current affordability standard under the Safe Drinking Water 

Act before promulgating any new NPDWRs in order to allow rural and small communities to utilize 

the most economical and safe treatment options (the so-called small system variance technologies). 

Under the Safe Drinking Water Act, the EPA must make a finding that their rules are "affordable" 

[(42 U.S.C. 300g-1(b) (15) (A)]. To determine affordability, EPA adopted a policy that families can 

afford annual water rates of 2.5% of median household income (MHI). 

The use of MHI computed as a national aggregate as the sole metric for determining affordability 

has many problems and should be revised to be reasonable for small communities and allow access 

to affordable compliance treatment options. EPA has stated that the purpose of their affordability 

determination is to "look across all the households in a given size category of systems and determine 

what is affordable to the typical, or middle of the road household" [Federal Register (Jan. 22, 2001) 

6975-7066]. EPA's MHI standard does not consider the quantity, concentration, rural demographics, 

and financial abilities of low-income families or disadvantaged populations to afford the rule as 

required by the Agency's Environmental Justice policy [Executive Order 12898]. 

The Congressional Research Service (Tiemann – October, 2007) published a report on the Safe 

Drinking Water Act for Congress, including a section on variances and affordability for small 

communities containing the following passage: 

"Prompted by intense debate over the revised arsenic standard and its potential cost to small 

communities, the [Congressional] conference report for EPA's FY2002 appropriations (H.Rept. 

107-272) directed EPA to review its affordability criteria and how small system variance programs 

should be implemented for the arsenic rule. EPA began the review and sought the advice of the 

EPA's National Drinking Water Advisory Council (NDWAC) and Science Advisory Board (SAB). 

After considering recommendations from its affordability work group, the NDWAC reported to 

EPA in 2003. The council acknowledged the statutory basis for small system variances and 

recommended changes, but cautioned that "significant practical, logistical, and ethical issues mitigate 

against the use of variances." The National Rural Water Association, a member of the NDWAC 

work group, dissented and issued a separate report urging EPA to adopt a safe and affordable 

variance approach that would make variances available to small communities, as authorized by 

Congress." 

It appears EPA agrees that their affordability policy is not appropriate for small communities. After 

reviewing the competing recommendations cited in the CRS report, EPA concluded the following in 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 17 of 67

March, 2006, "Some stakeholders have argued that the current criteria are too stringent and fail to 

recognize situations in which a significant minority of systems within a size category may find a 

regulation unaffordable. After seven years of experience with the current criteria, EPA agrees it is 

time to consider refinements to address the situations of communities with below average incomes 

or above average drinking water and treatment costs (FR p.10671 – March, 2007)." EPA has not 

finalized a new policy after making this declaration in 2006. 

We appreciate the opportunity comment on the Agency's proposal and look forward to 

collaborating with the Agency in implementation of the final rule.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Paul Cicio 

Commenter Organization: Industrial Energy Consumers of America 

Letter ID: 0024 

Comment ID: 32251 

Comment Code: 24000 

Comment: December 19, 2014 

Water Docket Environmental Protection Agency Mailcode: [28221T] 1200 Pennsylvania Avenue, 

NW Washington, DC 20460 

RE: Revised Comments – Preliminary Regulatory Determinations for Contaminants on the Third 

Drinking Water Contaminant Candidate List, Docket ID No. EPA-HQ-OW-2012-0155

We are pleased to submit these comments on the U.S. Environmental Protection Agency's (EPA) 

notice of preliminary determination for constituents found in US drinking water systems. In this 

proposed determination, EPA determines that four constituents do not warrant national drinking 

water standards and one constituent, strontium, does. We are submitting comments on EPA's failure 

to estimate the social benefits and social costs in its analysis for the determination. Specifically, in its 

analysis for the determination, EPA failed to consider the additional energy usage and its associated 

externalities in this rulemaking. 

The Industrial Energy Consumers of America is a nonpartisan association of leading manufacturing 

companies with $1.0 trillion in annual sales, over 2,900 facilities nationwide, and with more than 1.4 

million employees worldwide. It is an organization created to promote the interests of 

manufacturing companies through advocacy and collaboration for which the availability, use and 

cost of energy, power or feedstock play a significant role in their ability to compete in domestic and 

world markets. IECA membership represents a diverse set of industries including: chemical, plastics, 

steel, iron ore, aluminum, paper, food processing, fertilizer, insulation, glass, industrial gases, 

pharmaceutical, building products, brewing, independent oil refining, and cement. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 18 of 67

Under the Safe Drinking Water Act Amendments (SDWA) of 1996, EPA must make a regulatory 

determination every five years on at least five unregulated contaminants. A regulatory determination 

is a decision about whether or not to begin the process to propose and to promulgate a national 

primary drinking water regulation (aka a "maximum contaminant level" or "MCL") for an 

unregulated contaminant. These unregulated contaminants are chosen from the Contaminant 

Candidate List (CCL).

In its determinations concerning the third CCL list (CCL3), the agency is making preliminary 

determinations to regulate one contaminant (i.e., strontium) and to not regulate four contaminants 

(i.e., 1, 3- dinitrobenzene, dimethoate, terbufos and terbufos sulfone).

EPA's Failure to Estimate the Social Benefits and Costs of its Proposed Determination

EPA should conduct a social benefit-cost analysis for this proposed determination. EPA is required 

to conduct an analysis by Executive Order 13563. This Executive order amends Executive Order 

12866. Executive Order 12866 defines a “regulatory action” as

"Regulatory action" means any substantive action by an agency (normally published in the Federal 

Register) that promulgates or is expected to lead to the promulgation of a final rule or regulation,

including notices of inquiry, advance notices of proposed rulemaking, and notices of proposed 

rulemaking [FN1: Regulatory Planning and Review, Executive Order 12866, October 3, 1993.].

EPA's proposed determination is a regulatory action. EPA published it in the Federal Register. 

Under the SDWA amendments, EPA's determination is a perquisite for regulation and requires EPA 

to issue an MCL regulation within stipulated statutory deadlines. OMB declared it a significant

regulatory action since the draft determination underwent interagency review. By determining that 

certain constituents warrant an MCL, EPA is publishing a substantial action that will lead to 

regulatory control of strontium in drinking water sources.

In addition, the health risk levels (HRL) and hazard assessments in this proposed determination are 

likely to have immediate economic impact. Since it is foreseeable that private parties and other 

government agencies will use the HRLs in the proposed determination to require expenditure of 

resources, this proposed determination has social benefits and social costs that EPA should evaluate. 

As EPA states, recent groundwater sampling data in Illinois and Indiana show strontium levels 

above EPA's HRL [FN2: Regulatory Determination Support Document, EPA Report 815-R014-

003, pp. 5-20-1.]. Water systems are likely to face calls from their customers and state agencies to 

treat and to reduce these levels based on EPA's publication for the first time of a risk level in this 

proposed determination.

Since EPA did not conduct a social benefit-cost analysis, we are unaware whether the impact is 

economically significant. However, it is likely that the social costs are significant. EPA estimates that 

about 10 million people could be consuming drinking water above the HRL for strontium.

Therefore, under Executive order requirements for regulatory review, EPA must conduct a social 

benefit-cost analysis for its proposed determination.

Consideration of Energy Use and Attendant Externalities in its Social Cost Estimates
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Water systems that take action to reduce strontium levels below the HRL in response to the 

proposed determination and in the future have various treatment options. EPA states that the most 

likely treatment technologies are ion exchange, adsorption, and membrane filtration systems. These 

three technologies have one common characteristic: they will increase the energy required to provide 

a gallon of drinking water. This energy use, and its attendant social externalities, must be included in 

EPA's required benefit-cost analysis. Regulations direct firms and consumers to use more energy, 

thus increasing society's CO2 emissions, as compared to a baseline conditions without the 

regulation. EPA recently acknowledged this energy penalty as a regulatory effect in a major 

rulemaking, the standards for cooling water intake structures for electricity generating units and

manufacturers (aka the “316(b) rulemaking”). In its regulatory analysis, EPA stated:

Decreases in GHG emissions, measured as CO2 equivalents, may reduce the burden of global 

climate change to society in future years, and thus may create a positive benefit to society, while 

increases in GHG emissions can impose a negative benefit, or cost, to society. EPA refers to the

costs from increased emissions as the social cost of carbon (SCC)....EPA estimated the benefit, or 

cost, to society from changes in GHG [greenhouse gas emissions] emissions expected to result from 

the final rule and other options considered. EPA estimated the change in CO2 emissions resulting 

from the energy penalty associated with closed-cycle recirculating system technology, auxiliary 

energy requirements for operating compliance technology, and technology installation downtime for 

Electric Generators. Energy penalty effects result from reduced energy conversion efficiency of the 

power generating system [FN3: U.S. Environmental Protection Agency, Benefits Analysis for the 

Final Section 316(b) Existing Facilities Rule, EPA-821-R-14-005, May 2014 pg. 9-1.].

In the 316(b) rulemaking, EPA extended its use of SCC for regulatory costs in two important ways. 

First, EPA recognized the interconnection of the electricity grid. If a rule leads electricity generating 

units (EGUs) to use more electricity to operate, then that amount of electricity diverted to regulatory 

compliance must still be provided to other consumers by other EGUs and must lead to increased 

GHG emissions in our economy. Second, EPA applied the SCC estimate for this regulatory cost 

across the different regulatory options considered. This consistent application revealed that the net 

benefits for more costly controls are negative once the SCC value is included.

Limitations in EPA's 316(b) Analysis However, EPA's 316(b) analysis did not capture other energy 

use required to comply with this regulation. These limitations are listed below:

* Transmission Losses. In the 316(b) rule, EGUs or facilities generating electricity must replace the 

additional electricity consumed on-site with electricity purchased from other generators. Although 

the text is unclear, the analysis appears to calculate the SCC only to replace on- site loss of 

generation [FN4: Ibid, see pg. 9-3.]. In reality, it requires a greater amount of generation at the offsite EGU to fulfill this new, on-site demand due to losses in electricity transmission and distribution 

[FN5: For EGU compliance, the transmission distance from the new EGU source to the load may 

be greater or lower than from the affected EGU. However, under economic dispatch, the new EGU 

will have a marginally higher cost. The additional transmission costs will be included as part of this 

higher price. To be consistent with its SCC consideration, EPA should disentangle any additional 

transmission costs in these prices and estimate the additional cost from SCC considerations.]. The 

EIA estimates the average U.S. transmission loss is six percent [FN6: 

http://www.eia.gov/tools/faqs/faq.cfm?id=105&t=3]. When the regulatory consequence is ceasing 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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on-site generation, the analysis should include the regulatory cost (as valued by the SCC) of

transmission and distribution losses.

* Environmental Dispatch. For the foregone power generation or additional consumption, EPA 

models the additional amount of electricity (and GHG emissions) using an economic dispatch 

decision approach [FN7: U.S. Environmental Protection Agency, Benefits Analysis for the Final 

Section 316(b) Existing Facilities Rule, EPA-821-R-14-005, May 2014, Appendix I, pg. I-4.]. In other 

words, the grid operator fulfills increases in electricity demand by selecting the next, least-cost 

generating source. However, EPA has proposed that states modify grid dispatch rules to require 

environmental dispatch, favoring first EGUs with lower GHG emission rates [FN8: 79 FR 34830]. 

A shift to an environmental dispatch decision rule from an economic dispatch rule may increase the 

GHG emissions for the next unit of electricity, since the EGUs with the lowest GHG emission rates 

have been dispatched already.

Application in Other EPA Rulemakings to the CCL3 Rulemaking

Despite these limitations, EPA's SCC methodology in the 316(b) analysis advances previous EPA 

considerations of the SCC value in its regulatory cost analysis. One of the very few EPA rulemakings 

to consider this social cost was the final boiler and industrial furnace NESHAP for major sources. 

EPA's background documents for this rule include an estimate of the electricity requirements and 

resulting SCC costs for installation of air pollution control devices (APCDs) such as fabric filters,

electrostatic precipitators, and scrubber technologies [FN9: ERG, Revised Methodology for 

Estimating Control Costs for Industrial, Commercial, Institutional Boilers and Process Heaters 

National Emission Standards for Hazardous Air Pollutants – Major Source, January 2011]. In the 

background documents, EPA considers the electricity use of the APCDs and the electricity use of 

the fans and air handling equipment needed to route the exhaust stream to the control device.

For the CCL3 determination, EPA's establishment of the HRLs will precipitate action to reduce 

drinking water concentrations to below the HRLs. Public water systems will install treatment 

technologies that, like APCDs, consume electricity. The SCC cost of this data use must be included 

in EPA's required benefit-cost analysis of this determination. EPA's SCC Estimates Must be made 

to be Consistent with OMB Circular A-4 Before EPA applies any SCC estimate in its rulemaking, 

EPA must correct the methodological flaws that commenters have raised about the Interagency 

Working Group's SCC estimate. EPA's (and other federal agencies') past SCC estimates fail in terms 

of process and transparency. EPA's SCC estimates fail to comply with guidance for developing 

influential policy-relevant information under the Information Quality Act (IQA).

Further, EPA's SCC estimates are the product of an opaque process and any pretensions to their 

supposed accuracy (and therefore usefulness in policy-making) are unsupportable. The models with 

inputs used for the SCC estimates and the subsequent analyses were not subject to peer review, as 

appropriate. The SCC estimate integrated assessment modeling does not offer a reasonably 

acceptable range of accuracy for use in policy-making.

EPA has failed to disclose and quantify key uncertainties to inform decision makers and the public 

about the effects and uncertainties of alternative regulatory actions. By presenting only global SCC 

Estimates and downplaying domestic SCC estimates in 2013, the Interagency Working Group 

(IWG) has severely limited the utility of the SCC for use in benefit-cost analysis and policy-making.
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Recommendations 

* The SCC Estimates Must be made to be Consistent with OMB Circular A-4. As noted by leading 

researchers, the IWG SCC value is calculated differently than other measures of social benefits and 

costs [FN10: Gayer, T. and Viscose, K. Determining the Proper Scope of Climate Change Benefits, 

June 2014.]. Among other issues, it uses a lower discount rate than recommended by OMB Circular 

A-4 and values global benefits rather than solely U.S. domestic benefits. By introducing an SCC 

value with a different denomination in both the social cost and social benefit calculation, EPA 

muddies the results even more and renders comparison among regulatory options and among 

regulations even more difficult. The first step therefore should be to use a consistent framework 

across all consequences of regulation. 

* EPA Should Fix Limitations in its Past Applications of SCC as a Regulatory Cost. As shown 

above, EPA has not estimated the total energy implications across the economy from its regulatory 

requirements. EPA should adopt these improvements and an analytic scope that accounts for a 

rulemaking's incremental direct and indirect increases in energy used throughout the economy. 

* To be Consistent, EPA must include SCC as a Potential Cost in All Rules. EPA must include SCC 

in its social cost estimates to be consistent with the Executive orders on regulatory review and 

economic theory. The addition of SCC as a cost may shift on the margin the net benefits of a 

regulatory option from positive to negative. Regulatory actions requiring energy usage with relatively 

small social benefits may be the ones where policy officials want to understand the energy/SCC 

implications of the different regulatory options. Unless it is included in all regulatory analyses, policy 

officials will not know the effect of SCC costs. 

* If SCC is Used, OMB Should Require Uniform Application of SCC as a Potential Regulatory Cost 

Across Activities. EPA is not alone in its inconsistent application of SCC as potential regulatory 

costs. DOE and other federal agencies have inconsistent application of the SCC in their regulatory 

analyses. Few other agencies have acknowledged any potential energy/SCC externality in their 

rulemakings. If SCC is used, for it to fit with Circular A-4's requirements, both potential benefits and 

costs would need to be considered. 

Thank you for giving these points consideration. If you have any questions, or if we can be of 

further assistance, please feel free to contact me at (202) 223-1661.

Sincerely, 

Paul N. Cicio President

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Comment Code: 30500 Preliminary determination not to regulate dimethoate, 

1,3-dinitrobenzene, terbufos, and terbufos sulfone 

EPA Response to Comment Code 30500: Many commenters supported the EPA’s determination 

not to regulate four CCL 3 contaminants (1,3-dinitrobenzene, dimethoate, terbufos and terbufos 

sulfone) after evaluating these contaminants against the three SDWA criteria and considering the 

factors listed for each. EPA determined that none of these contaminants meet all three of the 

SDWA criteria required for regulation: 

(a) the contaminant may have an adverse effect on the health of persons; 

(b) the contaminant is known to occur or there is substantial likelihood that the contaminant will 

occur in public water systems with a frequency and at levels of public health concern; and 

(c) in the sole judgment of the Administrator, regulation of such contaminant presents a meaningful 

opportunity for health risk reduction for persons served by public water systems. 

If new health or occurrence information becomes available for the contaminants with previous 

negative determinations, this information will be reconsidered to evaluate whether the contaminant 

should be listed on the next CCL. For additional information on the preliminary determination to 

not regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone, see the discussion in 

section IV of the Federal Register Notice for the preliminary regulatory determinations (79 FR 

62716). 

Individual Comments 

 

Commenter Name: Matthew Corson 

Commenter Organization: American Water 

Letter ID: 0016 

Comment ID: 32144 

Comment Code: 30500 

Comment: December 18, 2014 

Water Docket Environmental Protection Agency Water Docket [Mailcode 28221T] 1200 

Pennsylvania Avenue, NW Washington, DC 20460 RE: Docket ID Number EPA-HQ-OW-2012-

0155

Comment Clerk: 

American Water appreciates the opportunity to provide feedback in response to the U.S. 

Environmental Protection Agency's (EPA) request for comment on the proposed regulatory 

determinations for contaminants on the Third Contaminant Candidate List (CCL3) as described in 

the October 20, 2014 Federal Register (79 FR 62715). American Water is active in 29 states and 

owns and/or contractually operates over 325 drinking water systems and therefore has a keen 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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interest in EPA's preliminary decision to regulate one contaminant (strontium) and to not regulate 

four contaminants (1,3-dinitrobenzene, dimethoate, terbufos and terbufos sulfone). 

With respect to the EPA's preliminary decisions, American Water: * Supports the negative 

determinations for 1,3-dinitrobenzene, dimethoate, terbufos and terbufos sulfone as they do not 

occur with a frequency and at levels of public health concern in public water systems as described by 

EPA in the Federal Register notice

EPA Response: Please see response to comment code 30500 Preliminary determination not to 

regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32166 

Comment Code: 30500 

Comment: 2. Support the four negative regulatory determinations;

EPA Response: Please see response to comment code 30500 Preliminary determination not to 

regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32173 

Comment Code: 30500 

Comment: 2. Support the four negative regulatory determinations;

EPA Response: Please see response to comment code 30500 Preliminary determination not to 

regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32181 

Comment Code: 30500 

Comment: 2. Four Negative Regulatory Determinations 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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AWWA supports the four negative regulatory determinations for 1,3- dinitrobenzene, dimethoate, 

terbufos, and terbufos sulfone. None of these four chemicals meet the second statutory criterion for 

occurrence, i.e., they do not occur at a frequency and at levels of public health concern in public 

water systems. Therefore, none of these four chemicals would provide a meaningful opportunity for 

risk reduction, the third statutory criterion in Section 1412(b)(1) of the Safe Drinking Water Act 

(SDWA).

EPA Response: Please see response to comment code 30500 Preliminary determination not to 

regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone. 

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action 

Letter ID: 0022 

Comment ID: 32226 

Comment Code: 30500 

Comment: We also support the determination not to begin the NPDWR process for Dimethoate, 

1,3 – dinitrobenzene, terbufos and terbufos sulfone given the lack of sufficient occurrence data to 

indicate the opportunity for meaningful public health risk reduction. In the Final Regulatory 

Determination, EPA should clarify how these contaminants would re-enter the regulatory process 

should further and differing data emerge on occurrence in the future.

EPA Response: Please see response to comment code 30500 Preliminary determination not to 

regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone. 

Commenter Name: Kevin Holbrooks 

Commenter Organization: JEA 

Letter ID: 0025 

Comment ID: 32240 

Comment Code: 30500 

Comment: Specific Comments: 

JEA supports EPA's preliminary determination that dimethoate, 1,3- dinitrobenzene, terbufos, and 

terbufos sulfone are not occurring, or occur infrequently, in drinking water and therefore that these 

contaminants do not require regulations for drinking water.

EPA Response: Please see response to comment code 30500 Preliminary determination not to 

regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone. 

Commenter Name: James Taft 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 

Letter ID: 0026 

Comment ID: 32245 

Comment Code: 30500 

Comment: Comments on Determinations Not to Regulate: 

The determination not to regulate a contaminant is just as important, in our view, as the decision to 

regulate. Such determinations avoid unnecessary regulation when there is little opportunity for 

improved public health protection and allow EPA and states to focus limited resources on 

contaminants where regulation can have a more positive effect. ASDWA agrees with EPA's decision 

that dimethoate, 1,3- dinitrobenzene, terbufos, and terbufos sulfone do not need to be regulated. 

Their very low occurrence rate, especially at levels of health concern (based on the data from 

UCMR2 and UCMR1) provides good support for this decision. 

EPA Response: Please see response to comment code 30500 Preliminary determination not to 

regulate dimethoate, 1,3-dinitrobenzene, terbufos, and terbufos sulfone. 

Comment Code: 33000 Preliminary determination to regulate strontium 

EPA Response to Comment Code 33000: Some commenters support the preliminary 

determination to regulate strontium while others recommended the agency conduct additional 

research and evaluations prior to making a final determination for strontium. The agency is not 

making a final regulatory determination for strontium at this time, so responses to comments related 

to strontium are not included in this document. The agency’s decision to delay a final determination 

for strontium is based on public comments received and the plan to further evaluate scientific 

information that became available after publication of the preliminary regulatory determinations. 

The agency will respond to comments below (other than those suggesting EPA postpone a decision 

on strontium pending further study) when a final determination is made for strontium. 

Individual Comments 

 

Commenter Name: Matthew Corson 

Commenter Organization: American Water 

Letter ID: 0016 

Comment ID: 32147 

Comment Code: 33000 

Comment: * Recommends EPA reconsider the positive regulatory decision for strontium and defer 

making a decision until a clearer and more complete analysis of health effects data is available and a 

more transparent analysis whether strontium does or does not occur with a frequency and at levels 

of public health concern in public water systems
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 26 of 67

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Anonymous 

Commenter Organization: 

Letter ID: 0013 

Comment ID: 32157 

Comment Code: 33000 

Comment: After research on the topic of strontium toxicology and personal, independent research 

conducted at my high school, I stand in favor of setting a maximum contaminant level on strontium 

of, at the very least, 1,000 mg/L. 

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Anonymous 

Commenter Organization: 

Letter ID: 0013 

Comment ID: 32160 

Comment Code: 33000 

Comment: The fact that there are so many unknowns about this substance but promising 

biochemical research that has indicated that excesses of strontium can potentially have serious, 

adverse health impact on humans (specifically children and pregnant women), this substance should 

be regulated with some sort of maximum contaminant level even if this maximum contaminant level 

is high. Regardless of whether or not strontium concentrations in United States drinking water have 

historically been recorded to reach levels near a proposed maximum contaminant level, a maximum 

contaminant level should be put in place to protect Americans from the futureâa future where 

strontium concentrations could quietly but rapidly increase in regions near modern gas extraction.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Emily Krafjack 

Commenter Organization: Connection for Oil, Gas, and Environment in the Northern Tier, Inc. 

(COGENT) 

Letter ID: 0014 

Comment ID: 32161 

Comment Code: 33000 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 27 of 67

Comment: December 5, 2014 

Water Docket Environmental Protection Agency Mailcode [28221T] 1200 Pennsylvania Ave. NW. 

Washington, D.C. 20460 

Submitted via: http://www.regulations.gov/ 

Re: Docket ID No. EPA-HQ-OW-2012-0155 Announcement of Preliminary Regulatory 

Determinations for Contaminants on the Third Drinking Water Contaminant Candidate List; 

Federal Register October 20, 2014; Vol. 79, No. 202; page 62716 

Dear Sir/Madam: 

Connection for Oil, Gas and Environment in the Northern Tier, Inc., C.O.G.E.N.T. focuses on 

Pennsylvania's five county region of Bradford, Sullivan, Susquehanna, Tioga and Wyoming 

Counties. C.O.G.E.N.T. is a resource for landowners and communities alike striving to find and 

advocate for a balance that supports public health and safety, community and the environment with 

the needs of industry. There are approximately 183,000 souls in the five county 3,987 square mile 

region, a region that hosts over 40% of Pennsylvania's unconventional natural gas wells. 

Unconventional gas well sites, gathering and transmission pipelines, and facilities have been located 

within and around our rural, farmland and forested communities, nearby family homes, schools and 

local hospitals. There are a variety of water related issues that have stemmed from natural gas drilling 

in our Region. This fact concerns us in relation to the occurrence of strontium both as naturally 

occurring and as introduced through natural gas exploitation industrial activity; thus we submit our 

comment. 

C.O.G.E.N.T. strongly supports the EPA making a determination to regulate strontium. 

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Emily Krafjack 

Commenter Organization: Connection for Oil, Gas, and Environment in the Northern Tier, Inc. 

(COGENT) 

Letter ID: 0014 

Comment ID: 32163 

Comment Code: 33000 

Comment: Let it be known that in consideration of the historical prevalence of strontium naturally 

occurring within our environment coupled with the vast activity of the unconventional natural gas 

industry within our Region and the associated propensity for spills contaminating drinking water 

supplies, it is imperative in order to adequately protect the public and ensure drinking water supplies 

are sufficiently safe that the EPA determine what the safe drinking level of strontium is, and that 

strontium become a regulated contaminant. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 28 of 67

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32168 

Comment Code: 33000 

Comment: 4. Issues with the positive regulatory determination for strontium that need to be 

considered prior to moving forward.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32175 

Comment Code: 33000 

Comment: 4. Issues with the positive regulatory determination for strontium that need to be 

considered prior to moving forward.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32183 

Comment Code: 33000 

Comment: 4. Strontium Considerations 

The preliminary positive determination for strontium raises many issues that need to be thoughtfully 

considered prior to any potential final determination and/or moving forward with a potential 

strontium regulation. EPA needs to get the science right on strontium before moving forward with a 

final positive determination and/or a potential strontium regulation. EPA needs to take the time to 

get the science right. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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It does not appear that there is any particular urgency for a strontium regulation at this time, since 

the water systems with high strontium levels such as Germantown, Wisconsin and Goforth, Texas 

have had high levels (40,000-50,000 ug/L) for generations. Given that the National Inorganics and 

Radionuclides Survey (NIRS) groundwater occurrence data have existed for more than 25 years, it 

might even be surmised that if gross skeletal effects were occurring in humans such as are being

inferred from the rat studies, they would have been observed in extreme exposure situations like 

Germantown and Goforth. EPA needs to take the time to do the necessary research and scientific 

evaluations before moving forward with a final positive determination and/or a potential strontium 

regulation.

To show its commitment to understanding some of the complex health effects and epidemiological 

issues, the American Water Works Association is funding an exploratory study. A preliminary 

exploration of the 2007-2012 databases from the National Health and Nutrition Examination

System (NHANES) revealed approximately 8,000 unique bone scan examination results (for a single 

variable). In order to determine whether there is an association between strontium and bone density, 

the UCMR3 and NHANES data must be linked geographically. Access to NHANES restricted data 

is only available through the National Center for Health Statistic's (NCHS) Research Data Center 

(RDC). This study is aimed at obtaining the restricted data from the RDC and performing a 

multivariate regression to determine whether there is an association between drinking water 

strontium concentrations and bone density. The results of this study will be shared with the 

appropriate EPA staff when the study is completed in March-April, 2015.

Strontium (as with almost everything) meets the first statutory criterion in Section 1412(b)(1) of the 

Safe Drinking Water Act (SDWA) for regulatory determinations; it may have an adverse effect on 

the health of persons. At high enough concentrations, just about any compound may have an 

adverse health effect. The currently unresolved issues for a regulatory decision will be focused on 

the second criterion; that the contaminant is known to occur or there is a substantial likelihood that 

the contaminant will occur at a frequency and at levels of public health concern, and the third 

criterion; that in the sole judgment of the Administrator, regulation of such contaminant presents a 

meaningful opportunity for health risk reduction for persons served by public water systems.

Regarding the second criterion, databases such as the ongoing UCMR3 monitoring demonstrate 

widespread detections, albeit with low detection/reporting levels, with some very high 

concentrations in a small number of water systems. The issue to be resolved is whether there are 

significant drinking water related adverse human health effects occurring, and if so at what drinking 

water concentrations, and if an MCLG/MCL would be exceeded with sufficient frequency. The 

answer to that question will determine whether a national drinking water regulation or a Drinking 

Water Health Advisory is warranted, or whether some state regulations would possibly be more 

appropriate, and whether there is meaningful opportunity for health risk reduction. Then it will be

necessary to determine the costs, benefits and feasibility of possible Maximum Contaminant Levels 

(MCLs).

It is interesting to note the impacts on the frequency of strontium occurrence resulting from the 

change in the HRL this year from 4,000 ug/L to 1,500 ug/L, based on the use of the age specific

exposure factors and the revised uncertainty factors. Based on the January 2014 UCMR3 data 

summary (with a HRL of 4,000 ug/L), 1.0% of systems had detects > HRL. When the HRL was 

changed this year to 1,500 ug/L, this percentage changed to 4.9% of systems. This change in the 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 30 of 67

HRL and how it relates to the percentage of systems impacted becomes even more interesting by 

reviewing the occurrence data used for the first two regulatory determinations. In the first regulatory 

determination in 2002, EPA decided not to regulate manganese with detects >HRL in 3.2% of the 

systems (Roberson, 2012). In the second regulatory determination in 2007, EPA decided not to 

regulate boron with detects >HRL in 1.7% of the systems. 

If one were to look at these two decisions as the boundary conditions for negative determinations, if 

a chemical occurs in <1.7%-3.2% of the systems, then a chemical should not be regulated and a 

negative determination should be made. The recent change in the strontium HRL "leap-frogged" 

these boundary conditions so that the national occurrence now appears robust enough to warrant a 

positive regulatory determination. While the ultimate decision for a positive or negative 

determination is "in the sole judgment of the Administrator", the above percentages show the 

sensitivity to changes that ultimately resulted in a lower HRL that could potentially impact more 

water systems. Again, this recent change in the HRL is significant and EPA needs to take the time to 

get the science right.

EPA Response: Thank you for your comment and commitment to understand some of the 

complex health effects and epidemiological issues pertaining to strontium. Please see response to 

comment code 33000 Preliminary determination to regulate strontium. 

Commenter Name: Rebecca Rotor 

Commenter Organization: Breathe Easy Susquehanna County (BESC) 

Letter ID: 0018 

Comment ID: 32194 

Comment Code: 33000 

Comment: Water Docket Environmental Protection Agency Mailcode [28221} 1200 Pennsylvania 

Avenue NW Washington, D.C. 2046

Submitted via: http://www.regulations.gov/ 

Re: Docket ID No. EPA-HQ-OW-2012-0155 Announcement of Preliminary Regulatory 

Determinations for Contaminants on the Third Drinking Water Contaminate Candidate List: 

Federal Register October 20, 2014: Vol. 79, No. 202; page 62716 

Dear Sir/Madam; 

Since there are no available standards for the human intake of strontium and since some health risks 

of strontium are known and some unknown BESC writes to support the EPA in making a 

determination to regulate strontium. 

Please see below BESC's attachment below.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 31 of 67

Commenter Name: Rebecca Rotor 

Commenter Organization: Breathe Easy Susquehanna County (BESC) 

Letter ID: 0018 

Comment ID: 32196 

Comment Code: 33000 

Comment: We urge the EPA to determine what the safe level of strontium is, and that strontium 

become a regulated contaminate.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32200 

Comment Code: 33000 

Comment: * Concerns about the positive regulatory determination for strontium

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32205 

Comment Code: 33000 

Comment: Concerns about the positive regulatory determination for strontium 

NRWA endorses the following excerpted portion of the American Water Works Association 

(AWWA) comments on this proposal that covers AWWA's "Questions on Strontium": 

"It does not appear that there is any particular urgency for a strontium regulation at this time, since 

the water systems with high strontium levels such as Germantown, Wisconsin and Goforth, Texas 

have had high levels (40,000-50,000 ug/L) for generations. The National Inorganics and 

Radionuclides Survey (NIRS) groundwater occurrence data have existed for more than 25 years, and 

there has been no particular urgency to develop a strontium regulation...
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 32 of 67

"Strontium (as with almost everything) meets the first statutory criterion in Section 1412(b)(1) of the 

Safe Drinking Water Act (SDWA) for regulatory determinations; it may have an adverse effect on 

the health of persons. At high enough concentrations, just about any compound may have an 

adverse health effect.

"The currently unresolved issues for a regulatory decision will be focused on the second [statutory 

criterion in Section 1412(b)(1) of the Safe Drinking Water Act (SDWA) for regulatory 

determinations]; that the contaminant is known to occur or there is a substantial likelihood that the 

contaminant will occur at a frequency and at levels of public health concern, and the third criterion; 

that in the sole judgment of the Administrator, regulation of such contaminant presents a 

meaningful opportunity for health risk reduction for persons served by public water systems.

"Regarding the second criterion, databases such as the ongoing UCMR3 monitoring demonstrate 

widespread detections, albeit with low detection/reporting levels, with some very high 

concentrations in a small number of water systems. The issue to be resolved is whether there are 

significant drinking water related adverse human health effects occurring, and if so, at what drinking 

water concentrations, and if an MCLG/MCL would be exceeded with sufficient frequency. The 

answer to that question will determine whether a national drinking water regulation or a Drinking 

Water Health Advisory is warranted, or whether some state regulations would possibly be more 

appropriate, and whether there is meaningful opportunity for health risk reduction. Then it will be

necessary to determine the costs, benefits and feasibility of possible Maximum Contaminant Levels 

(MCLs).

"It is interesting to note the impacts on the frequency of strontium occurrence resulting from the 

change in the HRL this year from 4,000 ug/L to 1,500 ug/L, based on the use of the age-specific 

exposure factors and the revised uncertainty factors. Based on the January 2014 UCMR3 data 

summary (with a HRL of 4,000 ug/L), 1.0% of systems had detects >HRL. When the HRL was 

changed this year to 1,500 ug/L, this percentage changed to 4.9% of systems. This change in the 

HRL and how it relates to the percentage of systems impacted becomes even more interesting by 

going back to the occurrence data used for the first two regulatory determinations. In the first 

regulatory determination in 2002, EPA decided not to regulate manganese with detects >HRL in 

3.2% of the systems (Roberson, 2012). In the second regulatory determination in 2007, EPA decided 

not to regulate boron with detects >HRL in 1.7% of the systems.

"If one were to look at these two decisions as the boundary conditions for negative determinations, 

if a chemical occurs in <1.7%-3.2% of the systems, then a chemical should not be regulated and a 

negative determination should be made. The recent change in the strontium HRL "leap-frogged" 

these boundary conditions so that the national occurrence now appears robust enough to warrant a

positive regulatory determination. While the ultimate decision for a positive or negative

determination is "in the sole judgment of the Administrator," the above percentages show the 

sensitivity to changes that ultimately resulted in a lower HRL that could potentially impact more 

water systems. Again, this recent change in the HRL is significant and EPA needs to take the time to 

get the science right.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium.
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 33 of 67

Commenter Name: James Slotterback, et al. 

Commenter Organization: Responsible Drilling Alliance 

Letter ID: 0021 

Comment ID: 32220 

Comment Code: 33000 

Comment: Strontium levels are routinely tested for in shale gas regions in pre- drilling baseline 

water tests conducted by well developers, property owners and public water supply operators. An 

increase in strontium levels post-drilling and well completion would be a clear indicator that fluids 

from shale layers have impacted water supplies. It would be extremely helpful to those impacted to 

have a known safe drinking water level for strontium in place for compliance by any party 

determined culpable by the Pennsylvania Department of Environmental Protection.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action 

Letter ID: 0022 

Comment ID: 32223 

Comment Code: 33000 

Comment: December 19, 2014

Water Docket U.S. Environmental Protection Agency 1200 Pennsylvania Ave. NW Washington DC 

20460 Attn: Docket ID No. OW-2012-0155

Clean Water Action Comments on the Preliminary Regulatory Determination for Contaminants on 

the Third Drinking Water Contaminant Candidate List 

We appreciate the opportunity to comment on the U.S. Environmental Protection Agency's (EPA) 

Preliminary Regulatory Determination for Contaminants on the Third Drinking Water Contaminant 

Candidate List. 

Clean Water Action is a national citizens' organization of 1 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 issues and on Safe Drinking Water Act implementation. 

Comments on Preliminary Determinations 

We support the decision to regulate strontium with a National Primary Drinking Water Regulation 

(NPDWR). Strontium meets the three Statutory Criteria set out in the Protocol for Regulatory 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 34 of 67

Determinations 3 and data from the 3rd Unregulated Contaminant Monitoring Rule will provide 

further information on occurrence. 

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Kevin Holbrooks 

Commenter Organization: JEA 

Letter ID: 0025 

Comment ID: 32239 

Comment Code: 33000 

Comment: December 19, 2014 

Attention Docket ID No EPA-HQ-OW-2012-0155. U.S. Environmental Protection Agency 1200 

Pennsylvania Avenue, NW Mailcode: 28221T Washington, DC 20460 

Submitted Electronically via Regulations.gov 

Dear Sir or Madame: 

JEA takes this method and opportunity to submit the following comments in reference to the 

Announcement of Preliminary Regulatory Determinations for Contaminants on the Third Drinking 

Water Contaminant Candidate List, published October 20, 2014 in the Federal Register. 

COMMENTS OF JEA 

On the Announcement of Preliminary Regulatory Determinations for Contaminants on the Third 

Drinking Water Contaminant Candidate List EPA Docket No. EPA-HQ-OW-2012-0155

BACKGROUND 

JEA is a municipally owned electric, water and wastewater utility serving over 1,000,000 people in 

Northeast Florida. JEA operates approximately 136 artesian wells that withdraw water from the 

Floridan aquifer where it is treated at one of 36 water treatment plants, then distributed thru 4,200 

miles of water pipes. Average daily usage is 103 MGD with a peak capacity of 298 MGD.

GENERAL COMMENTS 

EPA recently published a preliminary regulatory determination to initiate a rulemaking process to 

develop a national primary drinking water regulation for strontium. Although all statutory criteria 

were met which allowed the determination to be made, as stated in Federal Register Notice, more 

detailed analysis is now needed to develop any subsequent regulation. JEA encourages EPA to 

conduct extensive research prior to making any final decision to regulate strontium. Developing a 

regulatory standard for strontium levels in drinking water will require the installation of effective 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 35 of 67

removal treatment systems for those utilities which exceed the HRL, which is also a factor to be 

considered in the process.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Kevin Holbrooks 

Commenter Organization: JEA 

Letter ID: 0025 

Comment ID: 32242 

Comment Code: 33000 

Comment: JEA believes more time is needed to perform additional research prior to making a final 

determination to regulate strontium. EPA data indicates strontium has been detected in 99 percent 

of public water systems, but above Health Reference Levels (HRL) in only 7 percent of public water 

systems. While some JEA potable water samples have tested above the current HRL for strontium, 

we have not quantified any concerns from health professionals indicating that there have been any 

adverse health symptoms due to the level of strontium in drinking water. JEA water is supplied from 

an underground limestone aquifer that has high calcium content. This may potentially offset any 

weakening of bones that strontium substitution may cause. The link between how strontium ions 

exchange in the presence of high levels of calcium in drinking water needs to be further evaluated. It 

is imperative that the rule determination process identify the level of strontium in drinking water 

that would not endanger public health. Additionally, more extensive field testing of cost-effective 

treatment technologies to assess the effectiveness of strontium removal needs to be conducted. 

Although strontium meets the requirements for preliminary determination, JEA believes additional 

health and water treatment research is needed before any final determination is considered. 

CONCLUSION 

JEA appreciates the opportunity to comment on the preliminary regulatory determinations for 

contaminants on the third drinking water contaminant candidate list. Appropriately addressing the 

issues raised above will help assure that JEA can continue to plan for and maintain a robust, reliable, 

and economically viable water system for the communities that we serve 

Respectfully Submitted, 

Kevin Holbrooks Director, Lab and Water Services 

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Comment Code: 33150 Relative source contribution for strontium 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 36 of 67

Individual Comments 

 

Commenter Name: Matthew Corson 

Commenter Organization: American Water 

Letter ID: 0016 

Comment ID: 32149 

Comment Code: 33150 

Comment: * EPA should provide stronger justification for using a Relative Source Contribution 

(RSC) of 20% as the RSC has a significant impact on the RfD. 

American Water looks forward to working with EPA on review of these contaminants to ensure that 

future regulatory action is taken where appropriate to protect public health without overburdening 

water systems with new regulations that are not supported by sound science. Please direct any 

questions or concerns regarding these comments to my attention at (856) 727-6118 or 

matthew.corson@amwater.com. 

Sincerely, 

Matthew J. Corson, P.E. Manager, Environmental Compliance and Stewardship

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32186 

Comment Code: 33150 

Comment: Relative Source Contribution (RSC) 

The typical RSC defaults of 20% or 80% have utility in relatively simple circumstances where it is 

accepted that the drinking water component in the RSC is either very small or very large. It becomes 

much more relevant and essential for the RSC to be analyzed and quantified when the RSC is 

intermediate, and there is data to perform a meaningful estimate, because the impact on the MCLG, 

and ultimately the MCL and the impact on compliance costs can become significant. So, a thorough 

analysis of water and dietary exposure with appropriate statistical significance determinations will be 

necessary. A Monte Carlo approach might be necessary for a better quantitation of ranges in dietary 

patterns, drinking water concentrations, water consumption patterns, locations and population 

categories.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 37 of 67

Comment Code: 33200 Health effects of strontium (first criterion) 

Individual Comments 

 

Commenter Name: Matthew Corson 

Commenter Organization: American Water 

Letter ID: 0016 

Comment ID: 32148 

Comment Code: 33200 

Comment: While we recognize that strontium is being detected in numerous systems as part of the 

UCMR monitoring, American Water does not agree that the results being detected are necessarily at 

levels of concern due to uncertainty in the Reference Dose (RfD). We suggest that there are specific 

areas where EPA could improve its analysis of the RfD calculation. 

* Given that there are known water systems with higher levels of strontium, EPA should consider 

performing human epidemiology studies in those water systems and use the results to better inform 

the RfD. 

* EPA should provide stronger justification for its use of Uncertainty Factors (UFs) in calculating 

the RfD, specifically the use of 10 for Database Uncertainty (when 3 had been used in previous 

calculations) and how the UFs were appropriately adjusted for the fact that the RfD calculation 

includes an Age Specific Adjustment component.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Anonymous 

Commenter Organization: 

Letter ID: 0013 

Comment ID: 32152 

Comment Code: 33200 

Comment: Although further experimentation of greater sample sizes and vertebrate model 

organisms like mice is needed, regulation on the element should be treated in a very prudent 

manner. This is because although there do not seem to be any widely publicized cases of strontium 

ion concentration in water exceeding 116 mg/L, the substance is prone to extreme elevated 

concentrations since it is associated with human-inducing events like hydraulic fracturing. In 

addition, it is a tasteless, odorless element that is difficult to measure in water and so can easily be 

overlooked.
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 38 of 67

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Anonymous 

Commenter Organization: 

Letter ID: 0013 

Comment ID: 32158 

Comment Code: 33200 

Comment: After examining the effects of various strontium ion water concentrations on the 

lifespan, 72-hour mortality rate (which represented child mortality rate), and pupa production (which 

represented fertility) of Drosophila melanogaster, I concluded that exposure to 1,000 mg/L of 

strontium ion had a statistically significant adverse effect on all three factors compared to the 

control of 0 mg/L of strontium.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Anonymous 

Commenter Organization: 

Letter ID: 0013 

Comment ID: 32159 

Comment Code: 33200 

Comment: The following is some information I have accumulated regarding the biological impact 

of strontium on humans. 

Although strontium in drinking water has not historically been a major concern, is not regulated by 

the EPA with a MCL, and is sometimes used in dietary supplements, there is reason to believe that it 

could be harmful to human and organismal health. Strontium is a group 2 element on the periodic 

table right below Calcium and so has similar properties to Calcium. Both elements, for example, 

have 2 valence electrons in their natural state and so chemically bind with similar elements and 

compounds. These structural similarities often make the body mistake strontium for calcium 

accounting for similar behavior in the body. Strontium is known to compete with calcium for 

attachment on calcium protein carriers in blood and membrane receptor sites. 

Strontium often dissolves into the bloodstream and is absorbed into bones. After it is stored in 

bones, it sometimes reenters the bloodstream where it may return to be stored in a bone or released 

from the body as urine, feces, or sweat over a long period of time. Androgens may work against 

removal of strontium from the body in male individuals but if strontium was removed at high 

amounts, this could potentially overwhelm kidneys. In adults, strontium attaches to bone surfaces 

but in children whose bones are still developing, it can be used to create the hard bone itself. 

Although low levels of strontium have been used in therapeutic osteoporosis treatment, studies have 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 39 of 67

linked strontium intake to bone disorders such as rickets. A 2010 World Health Organization report 

indicated that strontium interfered with the normal crystalline growth of hydroxyapatite crystals in 

rats. Hydroxyapatite crystals are one of the components of human bones. Because calcium is also 

used for nerve function and blood clotting, strontium could potentially interfere with these bodily 

processes. In addition, few studies have ever been conducted regarding stable strontium toxicology. 

A 2004 Public Health Statement by the Agency for Toxic Substances and Disease Registry, for 

example, indicated that it is not known whether stable strontium affects reproduction in people. The 

effect of stable strontium on reproduction in animals is not known. 

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Emily Krafjack 

Commenter Organization: Connection for Oil, Gas, and Environment in the Northern Tier, Inc. 

(COGENT) 

Letter ID: 0014 

Comment ID: 32162 

Comment Code: 33200 

Comment: We presently do not have an extensive amount of information on strontium. We do 

know that problems in bone growth may occur with eating or drinking unusually high levels of 

strontium. (ATSDR) It is not known whether strontium affects reproduction in people. There is no 

information regarding whether or not strontium may be carcinogenic. There are issues with 

radioactive strontium. We know that Marcellus waste water has an association to radioactivity, but 

how much remains uncertain until the PA DEP publishes the long awaited TENORM Study. If 

there is a radioactive connection, how may strontium relate? The Federal Register notice contained 

information regarding the health effects of strontium. It noted there is a population more sensitive 

to the effects of strontium. We urge the EPA to give ample consideration to people in that greater at 

risk population group and thus promulgate sufficient regulations for strontium.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32185 

Comment Code: 33200 

Comment: Strontium Health Effects Issues 

Good epidemiology studies are needed to determine the appropriate No- Adverse- Effects-Level 

(NOAEL) 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 40 of 67

The Preliminary Third Regulatory Determination begs the question of why EPA is not actively 

pursuing commissioning some appropriate analytic epidemiology studies in several US water 

supplies with a range of strontium concentrations including the few relatively high levels identified 

in UCMR3 to determine whether and under what conditions strontium in drinking water and diet 

actually does have measurable and significant adverse effects. Strontium is likely one of the relatively

few drinking water chemical exposure scenarios that can be addressed for resolution with human 

epidemiology. The candidate water supplies are easily identifiable through UCMR3, water and 

dietary doses are determinable and the potential skeletal effects can be determined with non-invasive 

methods. Other potential negative and positive effects can be simultaneously evaluated. Water 

exposures have occurred in those water supplies for generations. Results of those human studies 

rather than extrapolation from rats would be a much more definitive and reliable basis for making a 

public health determination of potential risk and benefit, as the SDWA requires, and a Maximum 

Contaminant Level Goal (MCLG), if a regulation is needed. 

A reasonable timeframe would be required to complete these studies, but the need to complete these 

studies is significant. The analytic case control or cohort epidemiology studies should not be 

extremely expensive, and EPA should start these studies as soon as possible. Regardless of cost, 

those studies will be much less costly to the nation than an unnecessarily stringent MCLG/MCL 

that would have to be implemented virtually in perpetuity.

Database uncertainties in the Reference Dose (RfD) Calculation

This proposed RfD analysis utilizes standard Uncertainty Factors (UF) default factors of 10 for 

interspecies variability, and 10 for intraspecies variability, but 10 for database uncertainties; the

original IRIS database uncertainty factor was 3. The recitation of reasons for the major change from 

10 to 3 is not compelling and that "judgment call" is important because that alone accounts for a 

factor of about 10/3 (with rounding) in the ultimate RfD, which would lead to an MCLG and 

probable MCL with significantly different impact in water systems and different implementation 

costs. The stated HRL and potential MCLG, assuming 20% RSC is 1500 ug/L, whereas it would 

become as high as 5450 ug/L with 3 as the database uncertainty. EPA needs to demonstrate that 

there is no "double-counting" between the uncertainty factors and the age-specific exposure factors. 

Therefore the database uncertainty factor must have a very strong scientific justification and not be a

"judgment call".

The rationale is especially deficient since a more recent and apparently better designed toxicology 

study (Marie et al, 1985) with a better defined longer dosing period rather than the earlier (Storey, 

1961) study is being utilized along with a Benchmark Dose (BMDL) calculation. There is also ample 

support for a small database uncertainty from the 3 year Skoryna, 1981 rat dosing study that 

indicated no adverse effects, despite the detail questions. Even the EPA review concludes at p. 8-4: 

"a lower effect level is unlikely to be identified in a chronic study evaluating a broader array of 

tissues and endpoints than the single target (bone) evaluated in the co-critical studies by Marie et al

(1985), Grynpas and Marie (1990) and Storey (1961)". That statement alone dismisses the database 

uncertainty factor of 10.

The Kroes 1977 study is ambiguous in the notoriously thyroid sensitive rats at doses that are 

significantly above the vast majority of human exposures. Strontium is not genotoxic. The 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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calcium:strontium dietary ratio is also an important risk consideration for humans. The database that 

is cited along with the known chemistry of strontium does not indicate a plausible important human 

risk endpoint that is not recognized. That, along with the limited non-specific Turkish human study 

(Ozgur, 1996), does not lead to a conclusion that 10 versus 3 is a justifiable value, and perhaps a 

factor of one could even be justified based upon the nature of the existing information and the 

experience in the US, as could be resolved by appropriate epidemiology studies.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: James Slotterback, et al. 

Commenter Organization: Responsible Drilling Alliance 

Letter ID: 0021 

Comment ID: 32218 

Comment Code: 33200 

Comment: The Responsible Drilling Alliance advocates for the Precautionary Principle. We 

appreciate the work the EPA does to protect our environment, and therefore the health and safety 

of those we love, and our descendants. We are particularly concerned with the most vulnerable 

elements of society, our youngest generation. 

Because of strontium's ability to substitute for calcium in growing bone, we concur strontium meets 

statutory criterion for regulatory determinations. We concur that infants, children and adolescents 

are of particular concern. 

EPA Response: Please see response to comment code 10000 General comments about regulatory 

determinations and comment code 33000 Preliminary determination to regulate strontium. 

Comment Code: 33300 Occurrence of strontium (second criterion) 

Individual Comments 

 

Commenter Name: Emily Krafjack 

Commenter Organization: Connection for Oil, Gas, and Environment in the Northern Tier, Inc. 

(COGENT) 

Letter ID: 0014 

Comment ID: 32150 

Comment Code: 33300 

Comment: In Pennsylvania's Northern Tier Region, deep within the heart of the Marcellus Shale 

play, there are private water supplies having pre-drill baseline tests that indicated the presence of 

naturally occurring strontium in their private water supplies. 
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A study conducted by AECOM with A. Elizabeth Perry, PG as the lead researcher, noted that 

strontium was present in pre-drill baseline water tests. (July 2012) 

In a study of “Water Wells near Marcellus Gas Drilling Sites” lead researcher Bryan R. Swistock, 

M.S. Water Resources Extension Specialist it was noted that more than 30% of residents in most 

Marcellus counties rely on private water well or spring, which leaves the remaining 70%+/- relying 

on public water supplies. This study also collected data on strontium. It noted that there was no 

available drinking water standard for strontium. The study noted both typical concentrations found 

in Pennsylvania groundwater and the concentration of typical Marcellus waste water. The high 

concentration of strontium in waste water (1,080 mg/l) is relevant as private water wells have faced 

contamination issues due to waste water spillage. One interesting tidbit of the study is that in a 

Phase 1 Site Example, strontium was noted as .05 mg/l in the February 2010 pre-drill sample. The 

next sampling, July 2010 - one week post hydraulic fracturing the sample indicated .22 mg/l and 

then the next sampling 10 mos. The post fracturing, May 2011 sample indicated .14 mg/l. 

Strontium does occur naturally within our streams. For example, the SRBC has pulled 'grab samples' 

at the remote water quality monitoring station on Little Mehoopany Creek located in Wyoming 

County and those samples have noted the presence of strontium. The SRBC is pulling 'grab samples' 

about four times a year at the Remote Water Quality Network established to monitor streams in the 

Marcellus Shale Region. Samples are evaluated for a variety of substances including strontium. 

Thus, in our region, we have naturally occurring strontium in private water wells, streams and the 

propensity for gas industry waste water spillage containing extremely high levels of strontium. 

Presently, we do not have this information regarding public water supplies, but we have every reason 

to expect a mirror of naturally occurring strontium. A few of our hospitals are near or within the gas 

development area. In 2013, a Wyoming County hospital's water supply was within one mile of a well 

pad where a hydraulic fracturing blowout occurred and 200,000+ gallons of flowback was 

uncontrollably spilled. Nearby water supplies were monitored for possible contamination for quite 

some time. The PA DEP took special care to monitor the hospital's drinking water supply. 

Strontium is also often detected at hazardous waste sites throughout the United States. In 

Pennsylvania's Marcellus Shale Region, the exploitation is so new, we don't know what bearing 

hazardous waste sites may have to us in the future, but we do know that very likely, strontium will 

be present in the mix. 

Thus, with more opportunities for strontium to be present in many areas beyond traditional 

industrial locations, it is imperative that consideration be made to determine what a safe drinking 

level may be – and to regulate it.

EPA Response: Please see responses to comment code 33000 Preliminary determination to 

regulate strontium. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 
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Comment ID: 32190 

Comment Code: 33300 

Comment: Strontium Occurrence Data 

Completing the occurrence and national distribution databases and system size distribution analysis 

to include the more recent UCMR information as well as the NIRS data is important as the Agency 

moves forward in the regulatory development process, along with additional anecdotal reports. It is 

important to distinguish between raw water and finished water data. That will be essential for the 

exposure and impact determinations, and also whether strontium in drinking water is a national 

concern warranting a federal regulation or a Drinking Water Health Advisory. That also becomes 

the basis for projecting national impact in terms of number and types and sizes of impacted water 

supplies.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Rebecca Rotor 

Commenter Organization: Breathe Easy Susquehanna County (BESC) 

Letter ID: 0018 

Comment ID: 32195 

Comment Code: 33300 

Comment: Citizens are especially at risk from high concentrations of strontium from spills and 

disposal of waste products during the processes of Marcellus gas production.

EPA Response: Please see responses to comment code 33000 Preliminary determination to 

regulate strontium. 

Commenter Name: Rebecca Rotor 

Commenter Organization: Breathe Easy Susquehanna County (BESC) 

Letter ID: 0018 

Comment ID: 32197 

Comment Code: 33300 

Comment: Please also keep in mind that peer reviewed studies have shown that micro levels of 

contaminates can have debilitative developmental consequences, so there is a need to study at the 

parts per billion level to cover circumstances that occur where people are living with constant small 

dose exposures. 

Thank you for your consideration. 

Rebecca Rotor, President, BESC December 19, 2014 
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Mission/Goal: "To protect regional air quality and health of communities in Susquehanna County, 

Pa from potentially harmful air emissions released through the processes of shale gas extraction, 

production and transport." 

STRATEGY: "We will promote respectful dialogue between the natural gas industry and our 

Susquehanna County community. Although our members are bipartisan, we are non-partisan. We 

will advocate that industry act as good neighbors and partners through voluntary use of best 

technologies and processes for lowest possible air emissions at every stage of shale gas extraction, 

production and transport. Achieving the lowest air emissions possible beyond required regulations 

will help to keep our air healthy to breathe, and will help protect the health of everyone living and 

working in our community.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium 

Commenter Name: James Slotterback, et al. 

Commenter Organization: Responsible Drilling Alliance 

Letter ID: 0021 

Comment ID: 32217 

Comment Code: 33300 

Comment: December 19, 2014 

Water Docket Environmental Protection Agency Mailcode (28221T) 1200 Pennsylvania Ave. NW 

Washington, DC 201460 

Re: Docket ID No. EPA-HQ-OW-2012-0155 Announcement of Preliminary Regulatory 

Determinations for Contaminants on the Third Drinking Water Contaminant List; Federal Register 

October 20, 2014; Vol. 79, No. 202; page 62716 

Dear Madam or Sir, 

The Responsible Drilling Alliance appreciates the EPA's preliminary determination to regulate 

strontium. We strongly support moving forward with promulgating a national primary drinking 

water regulation for this element. 

The Responsible Drilling Alliance is a 501 (c) 3 corporation based in Lycoming County, 

Pennsylvania. We are an education and advocacy coalition dedicated to protecting communities and 

special places in the Marcellus Shale region of Pennsylvania. Our county, and the two that adjoin us, 

are among the top gas producing counties in the Commonwealth; Pennsylvania is now the second 

leading gas producing state in the nation. 

Shale gas well production declines quickly, and more wells must be drilled to keep production 

growing. The Marcellus is one of a number of layers of shale that underlies a large portion of our 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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state. Since significant production of natural gas from shale began in Lycoming and neighboring 

counties some six years ago, our region has seen a variety of water related problems. 

We now have over 700 active shale gas wells in Lycoming County. We anticipate there will 

eventually be over 10 times that number of wells drilled in our county into the Marcellus alone. 

Shale gas wells produce large volumes of hydrofracture flowback and production wastewater that 

must be managed. According to Pennsylvania chemist Timothy Keister, who manages wastewater 

professionally, a “typical” analysis of this wastewater in northeastern PA includes 4,000 mg/l of 

strontium. 

Gas industry toxic wastewater is handled and treated in a variety of ways throughout the 

Commonwealth. It is trucked to treatment facilities, stored on well sites in tanks, put into open 

impoundments, recycled on site and in centralized facilities. Solid waste from treatment procedures 

is put into landfills, heavy concentrations of toxic “brine” are injected into the ground at approved 

sites, some hundreds of miles away. 

The point is: there is a substantial volume of strontium, once sequestered a mile or more 

underground for millions of years, now being introduced into our environment. There are 

multitudes of opportunities for mishaps and mishandlings. We have seen gas wells blow out, 

spewing hundreds of thousands of gallons of toxic gas industry wastewater onto the ground and into 

streams. Impoundment ponds have leaked into groundwater within a half mile of public water 

supply wells. Impacted groundwater has leached into streams for extended periods of time. Toxic 

wastewater tank trucks crash with surprising regularity, spilling their entire contents into streams and 

on the ground above water wells. We have seen ongoing illegal dumping of toxic wastewater. Tank 

valves have been left open to spill thousands of gallons of toxic wastewater onto the ground and 

into streams. In addition, partially treated toxic wastewater was legally piped into waterways at 

allowable levels of 20 mg/l of strontium for a number of years before that limit was lowered by half. 

Salt concentrations in gas industry toxic wastewater, including strontium chloride, are extremely 

high. The total amount of these wastewaters is staggering.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: James Slotterback, et al. 

Commenter Organization: Responsible Drilling Alliance 

Letter ID: 0021 

Comment ID: 32221 

Comment Code: 33300 

Comment: There are many communities with public water supplies located in the shale gas regions 

in Pennsylvania and other states. There are many communities “off the shale” that draw water for 

treatment for public water supplies from waterways that are downstream from shale gas areas. 

Although we are relieved to report that strontium levels are not yet a problem in the public water 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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supplies we have researched, we concur that nationwide, strontium does occur at levels of public 

health concern in public water systems with enough frequency to meet SDWA statutory criterion.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Comment Code: 33400 Meaningful opportunity for health risk reduction for 

strontium (third criterion) 

Individual Comments 

 

Commenter Name: James Taft 

Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 

Letter ID: 0026 

Comment ID: 32247 

Comment Code: 33400 

Comment: Comments on Determination to Regulate: 

There is no doubt that strontium occurs consistently in public water systems. Evidence from initial 

UCMR3 monitoring supports that conclusion. The question is whether enough water systems show 

strontium at levels of concern that a meaningful reduction in health risk can be achieved through a 

national regulation. This is always a major concern for states because a national rule will increase the 

state burden for implementation universally, even if only a very small number of systems have a 

significant potential health issue. ASDWA understands that AWWA is currently engaging in research 

studies that will provide a better understanding of the health impact in some communities with 

historically high strontium and has proposed that EPA itself conduct some additional health related 

evaluations. Because of the significant impact on all water systems of a regulation that potentially 

only benefits a few, ASDWA would support delaying a final decision on regulation until this 

additional information can be gathered and analyzed. 

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium 

Comment Code: 33500 Costs and benefits of regulating strontium 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Letter ID: 0017 

Comment ID: 32184 

Comment Code: 33500 

Comment: From a national cost of compliance perspective, strontium could be close to arsenic and 

the cost of compliance with the arsenic regulation was significant. The arsenic regulation impacted 

many groundwater systems, and many of these systems were small and very small systems. In the 

2001 arsenic rule (66 FR 6975), EPA estimated that 5.3% of systems would be impacted by the 

revised arsenic MCL of 10 ug/L, with the national cost of compliance estimated at between $180.4 

and $205.6 million per year (1999 dollars). For systems serving 101-500 people, EPA estimated the 

mean annual cost per household for the additional treatment to be $14/month (1999 dollars). For 

systems, serving <100 people, the mean annual cost per household was estimated at $27/month 

(1999 dollars). 

The Agency used a science-based approach to ensure that the health effects information used in the 

development of the arsenic regulation was the best available, peer-reviewed science. Using the NIRS 

data and the UCMR3 data as the boundary conditions, 4.9%-7.0% of systems could be potentially 

impacted by a strontium regulation at the HRL of 1,500 ug/L. The 5.3% of systems that EPA 

predicted would be impacted by the 2001 arsenic rule falls in between this range. EPA should 

undertake a similar research effort for strontium for additional health effects and treatment data, 

comparable to what was undertaken for arsenic in the 1990s prior to moving forward with a final 

positive determination and/or a potential strontium regulation

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32191 

Comment Code: 33500 

Comment: Regulatory Impact and Technology 

The Agency needs to get the science right before moving forward with a final positive determination 

and/or a potential strontium regulation. If the Agency decides to move forward with a strontium 

regulation, several benefit-cost factors will have to be taken into consideration in the regulatory 

development process. Additional treatment research would be a critical component of the regulatory 

development process for a potential strontium research. 

To show its commitment to understanding the potentially complex treatment issues, the American 

Water Works Association, in partnership with the Water Research Foundation, is starting a review of 

treatment technologies for strontium. This project will start in January 2015 and will conduct a 

critical review of existing literature on strontium and related metals removal from water, as well as 

conducting exploratory lab-scale evaluations of the form in which strontium is found in different 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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water quality conditions. The findings will be synthesized into a report that will make 

recommendations for a future research project focused on evaluating strontium treatment options at 

the bench- scale, including potential treatment technologies that should be included as well as water 

quality parameters and conditions that may impact removal and therefore should be evaluated in 

such an investigation. This report will be shared with the appropriate staff at EPA. 

In some cases, water systems with higher strontium concentrations will likely also be hard waters 

with higher calcium or magnesium concentrations. The treatment technology for hard waters, 

including strontium will be some form of water softening. On the one hand because of the closely 

related chemistry of the alkaline earth metals, the additional calcium and possibly magnesium intake 

from hard water will be a positive factor partially countering the uptake of strontium. On the other 

hand, many hard waters will have central softening, or many homes in hard water areas will have 

installed water softeners. That needs to be reflected in the exposure and risk and benefits impact 

analyses, as well as in the cost impact analyses. 

Additionally, some animal and epidemiological studies show cardiovascular benefits from 

consumption of drinking waters containing magnesium, which is removed concurrently by water 

softening. So, that would be a negative impact to be evaluated in the benefits and risk analyses for 

strontium reduction. 

The cost and technology analyses should also include the opportunities for decentralized community 

water treatment in small communities, which is specifically allowed in the SDWA.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32206 

Comment Code: 33500 

Comment: "From a national cost of compliance perspective, strontium could be close to arsenic 

and the cost of compliance with the arsenic regulation was significant. The arsenic regulation 

impacted many groundwater systems, and many of these systems were small and very small systems. 

In the 2001 arsenic rule (66 FR 6975), EPA estimated the national cost of compliance with the 

revised arsenic MCL of 10 ug/L at between $180.4 and $205.6 million per year (1999 dollars). For 

systems serving 101-500 people, EPA estimated the mean annual cost per household for the 

additional treatment to be $14/month (1999 dollars). For systems, serving <100 people, the mean 

annual cost per household was estimated at $27/month (1999 dollars). 

"The Agency used a science-based approach to ensure that the health effects information used in the 

development of the arsenic regulation was the best available, peer-reviewed science. Using the NIRS 

data and the UCMR3 data as the boundary conditions, 4.9%-7.0% of systems could be potentially 

impacted by a strontium regulation at the HRL of 1,500 ug/L. The 5.3% of systems that EPA 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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predicted would be impacted by the 2001 arsenic rule falls in between this range. EPA should 

undertake a similar research effort for strontium for additional health effects and treatment data, 

comparable to what was undertaken for arsenic in the 1990s prior to moving forward with a final 

positive determination and/or a potential strontium regulation. 

[Excerpted from the American Water Works Association's (AWWA) comment on the October 20, 

2014 Federal Register notice (79 FR 62715) regarding the Preliminary Regulatory Determinations for 

Contaminants on the Third Drinking Water Contaminant Candidate List (CCL3), December, 2014]

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Commenter Name: James Taft 

Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 

Letter ID: 0026 

Comment ID: 32248 

Comment Code: 33500 

Comment: If indeed the final decision is to go forward with regulations, ASDWA hopes EPA will 

craft a regulation that provides flexibility to reduce the burden on water systems that only have very 

low levels of strontium.

EPA Response: Please see response to comment code 33000 Preliminary determination to regulate 

strontium. 

Comment Code: 40000 EPA's decision to postpone determinations for 

nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate 

EPA Response to Comment Code 40000: All commenters addressing the Agency’s plan to 

address chlorate and nitrosamines in the context of review of the existing DBP regulations 

supported the Agency’s approach. Because chlorate and nitrosamines are disinfection byproducts 

(DBPs) that can be introduced or formed in public water systems partly because of disinfection 

practices, it is important to evaluate these unregulated DBPs in the context of the review of the 

existing DBP regulations. DBPs need to be evaluated collectively, because the potential exists that 

the chemical disinfection used to control a specific DBP could affect the concentrations of other 

DBPs. 

EPA will continue efforts focused on identifying and analyzing the relevant data in order to assess 

health effects associated with NDMA. This includes new information related to relative exposure by 

multiple routes. EPA will also analyze data from UCMR 3 monitoring for chlorate as part of the SixYear Review of the DBP regulations. Therefore, as discussed in the notice of the preliminary 

determination, the agency is not making a regulatory determination for chlorate and nitrosamines at 

this time. 
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Individual Comments 

 

Commenter Name: Matthew Corson 

Commenter Organization: American Water 

Letter ID: 0016 

Comment ID: 32146 

Comment Code: 40000 

Comment: * Supports including chlorate and nitrosamines in the upcoming Six-Year Review so as 

to allow for consideration of simultaneous compliance issues as described by EPA in the Federal 

Register notice

EPA Response: Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32165 

Comment Code: 40000 

Comment: AWWA's comments on the Preliminary Regulatory Determinations fall into four major 

categories that are detailed in the enclosed comments: 

1. Support the inclusion of chlorate and nitrosamines in the Third Six- Year Review;

EPA Response: Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32172 

Comment Code: 40000 

Comment: AWWA's comments on the Preliminary Regulatory Determinations fall into four major 

categories: 

1. Support the inclusion of chlorate and nitrosamines in the Third Six- Year Review;
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EPA Response: Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32176 

Comment Code: 40000 

Comment: 1. Chlorate and Nitrosamines 

AWWA agrees with EPA regarding the inclusion of chlorate and nitrosamines in the Third Six-Year 

Review as part of the review of the Microbial/Disinfection By-Product (M/DBP) regulations. 

Maintaining the risk balancing between adequate disinfection and DBP control continues to be a 

critical goal for maintaining the necessary public health protection. Maintaining this balance has been 

the foundation of the M/DBP regulations that have been developed over the last two decades. 

AWWA believes that serious data gaps need to be filled when it comes to both chlorate and 

nitrosamines before a regulation can be developed for either of these two, and we are hopeful that 

the Six-Year Review process will help EPA focus its research effort and resources to address these 

data gaps prior to any potential revision of the M/DBP regulations.

EPA Response: Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Commenter Name: Lynn Thorp 

Commenter Organization: Clean Water Action 

Letter ID: 0022 

Comment ID: 32225 

Comment Code: 40000 

Comment: We support the decision to consider chlorate and nitrosamines as part of the Six Year 

Review of Disinfection Byproducts Regulation.

EPA Response: Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Commenter Name: Kevin Holbrooks 

Commenter Organization: JEA 

Letter ID: 0025 

Comment ID: 32241 

Comment Code: 40000 
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Comment: JEA supports EPA's decision not to pursue regulations for Chlorates and Nitrosamines 

at this time. JEA agrees that because chlorate and nitrosamines are Disinfection By-Products (DBPs) 

that can be introduced or formed in public water systems partly because of disinfection practices, it 

is important to evaluate these unregulated DBPs in the context of existing DBP regulations. DBPs 

need to be evaluated collectively because the potential exists that the chemical disinfection used to 

control a specific DBP could affect the concentrations of other DBPs.

EPA Response: Thank you for your support. Please see response to comment code 40000 EPA's 

decision to postpone determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, 

NPYR) and chlorate. 

Commenter Name: James Taft 

Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 

Letter ID: 0026 

Comment ID: 32249 

Comment Code: 40000 

Comment: Comments on Determinations to Defer a Regulatory Decision: 

ASDWA recognizes that nitrosamines and chlorate need to be seriously considered for regulation. 

The results from UCMR2 and initial results from UCMR3 indicate they are found in significant 

numbers of public water systems and potentially, at levels of a health concern. However, these 

contaminants are also closely tied to drinking water disinfection and the management of disinfection 

by products. Independent action on chlorate and nitrosamines, without considering the effect on the 

implementation of the existing regulations, could cause simultaneous compliance challenges that 

could actually have a negative impact on public health. The combined analysis will add to the already 

challenging Six Year Review, but it is the best approach for assuring there will not be unintended 

consequences.

EPA Response: EPA agrees with the commenter. Please see response to comment code 40000 

EPA's decision to postpone determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, 

NMEA, NPYR) and chlorate. 

Comment Code: 41000 Nitrosamines 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32180 
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Comment Code: 41000 

Comment: The six-year review of Stage 2 Disinfectant/Disinfection By-Product Rule (DBPR) 

might be the appropriate time and regulatory process to make a regulatory decision for nitrosamines 

assuming that the data gaps identified herein are addressed by that time. 

Simultaneous compliance with existing regulations is one important issue, as well as 

"antibacksliding" for microbial protection, need to be considered for nitrosamines in the context of 

the Third Six-Year Review. Most potential compliance approaches for a potential NDMA regulation 

would present simultaneous compliance challenges with existing regulations such as the Stage 2 

DBPR and Long-Term 2 Enhanced Surface Water Treatment Rule (LT2SWTR). Many water 

systems have switched to chloramination as a compliance strategy for the Stage 2 DBPR and EPA 

needs to ensure that that compliance strategy is not compromised in the Agency's holistic review of 

the M/DBP regulations. 

EPA Response: EPA agrees with the commenter on the comment. Please see response to 

comment code 40000 EPA's decision to postpone determinations for nitrosamines (NDBA, NDEA, 

NDMA, NDPA, NMEA, NPYR) and chlorate. 

Comment Code: 41150 Relative source contribution for nitrosamines 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32178 

Comment Code: 41150 

Comment: Like chlorate, the research question for nitrosamines is the RSC, as it appears that the 

drinking water risk from nitrosamines is negligible. In 2007, Fristachi and Rice predicted the 

proportional oral intake (POI) of N-nitrosodimethylamine (NDMA) attributable to drinking water 

consumption to be 0.02% relative to exogenous and endogenous sources combined (Journal of 

Water and Health, 2007). When only exogenous sources were considered, the POI was predicted to 

increase to only 2.7%. Clearly, the relative proportion of NDMA consumed through drinking water 

as opposed to other foods and what is generated by the body is very small. This research result was 

expanded by a research team led by Dr. Steve Hrudey (Risk Analysis, 2013). This research team 

found that drinking water contributes a mean proportion of the lifetime average daily NDMA dose 

ranging from 0.0002%-0.001% for surface water systems using chlorine or between 0.001%-0.01% 

for surface water systems using chloramine. 

EPA Response: EPA appreciates the information provided by the commenter. EPA will continue 

to evaluate this information along with any newly available information in this area. In addition, 

EPA will take sensitive sub-populations (e.g., infants) into account while assessing relative exposure 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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by multiple routes. Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Comment Code: 41400 Meaningful opportunity for health risk reduction for 

nitrosamines (third criterion) 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32179 

Comment Code: 41400 

Comment: Based on the two research studies, regulating NDMA in drinking water would likely not 

provide a meaningful opportunity for risk reduction as required by the SDWA.

EPA Response: Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Comment Code: 42150 Relative source contribution for chlorate 

Individual Comments 

 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32177 

Comment Code: 42150 

Comment: For chlorate, the main data gap is in determining the appropriate Relative Source 

Contribution (RSC) in drinking water. As part of the Third Unregulated Contaminant Monitoring 

Rule (UCMR3), EPA developed an initial Health Reference Level for chlorate of 210 ug/L, 

assuming the default 20% RSC for chlorate in drinking water. Clearly, a much higher RSC is 

appropriate, perhaps as high as the 80% default, as used by Canada and the World Health 

Organization, after a careful quantitative analysis of dietary exposure is provided. Incremental 

indirect exposure is possible from certain foods cooked in drinking water containing chlorate. This 

may well be already accounted for in the remaining 20% from an 80% RSC default. The significance 

of this exposure factor should be quantified and justified as a contribution to long term total diet. 

The dominant route of exposure is from drinking water when water systems use hypochlorite or 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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chlorine dioxide for the required disinfection (Cotruvo, letter to the Editor of Journal – AWWA, 

April, 2014). Using an 80% RSC would lead to a revised HRL or potential MCLG of 840 ug/L, 

which would be between Health Canada's guideline of 1,000 ug/L and the World Health 

Organization's guideline of 700 ug/L. This important RSC question needs to be answered as part of 

EPA's consideration of chlorate in the context of the Third Six-Year Review.

EPA Response: Please see response to comment code 40000 EPA's decision to postpone 

determinations for nitrosamines (NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and chlorate. 

Comment Code: 42300 Occurrence of chlorate (second criterion) 

Individual Comments 

 

Commenter Name: Jonathon T. Busch 

Commenter Organization: American Chemistry Council (ACC) 

Letter ID: 0020 

Comment ID: 32216 

Comment Code: 42300 

Comment: December 19, 2014 

Zeno Bain Water Docket US Environmental Protection Agency; Mailcode: 28221T 1200 

Pennsylvania Ave., NW Washington, DC 20460 

RE: Docket ID No. EPA-HQ-OW-2012-0155 Preliminary Regulatory Determinations for 

Contaminants on the Third Drinking Water Contaminant Candidate List, 79 FR 62716 (October 20, 

2014)

Dear Mr. Bain: 

The Sodium Chlorite/Chlorine Dioxide Panel (Panel) of the American Chemistry Council 

appreciates the opportunity to comment on the U.S. Environmental Protection Agency's (Agency) 

proposed rule titled “Announcement of Preliminary Regulatory Determinations for Contaminants

on the Third Drinking Water Contaminant Candidate List”, particularly as it pertains to the Agency's 

ongoing evaluation of chlorate in drinking water as discussed in section V of the referenced Federal 

Register notice at page 62741. 

The Sodium Chlorite/Chlorine Dioxide Panel represents the manufacturers and distributors of 

sodium chlorite used to generate chlorine dioxide for a variety of antimicrobial uses, including 

disinfection of drinking water. The Panel includes the following member companies: BASF 

Corporation; Bio-Cide International Inc; CDG Environmental; International Dioxcide Inc. (IDI); 

ERCO Worldwide, Inc.; Evoqua Water Technologies; and Occidental Chemical Corporation 

(formerly Basic Chemicals Company LLC). 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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The possible regulation of chlorate as a disinfection byproduct in drinking water is of significant 

interest to the Panel as it will directly impact the use of chlorine dioxide in drinking water 

disinfection. 

The Panel observes that in its occurrence characterization, the Agency has combined the chlorate 

occurrence data from systems using sodium hypochlorite and chlorine dioxide for disinfection. It is 

important to note that while chlorate may make its way to finished drinking water through either of 

these disinfectants, the mechanisms for doing so are quite different. Chlorine dioxide must be 

generated on site from a chemical precursor. There are a number of approved methods for 

accomplishing this chemical reaction. Both the method of chlorine dioxide generation and the 

generation equipment affect the potential for producing byproduct chlorate. 

The Panel would welcome the opportunity to meet with the Agency to provide additional input as 

the evaluation of chlorate proceeds. Should you have any questions regarding these comments, 

please contact us. 

Sincerely, 

Jonathon T. Busch Manager, Sodium Chlorite/Chlorine Dioxide Panel Director, Chemical Products 

and Technology Division American Chemistry Council (ACC) 200 2nd Street NE Washington DC 

2002 Phone: (202) 249-6725 Email: jon_busch@americanchemistry.com

EPA Response: Thank you for the comment and the information provided. The new national 

occurrence dataset for chlorate from UCMR 3 will enable EPA to assess chlorate occurrence with 

use of chlorine dioxide, hypochlorite, and chlorine dioxide plus hypochlorite. Please see response to 

comment code 40000 EPA's decision to postpone determinations for nitrosamines (NDBA, NDEA, 

NDMA, NDPA, NMEA, NPYR) and chlorate. 

Comment Code: 50000 Other contaminants 

EPA Response to Comment Code 50000: Commenters recommended determinations for several 

additional contaminants. The Safe Drinking Water Act (SDWA), as amended in 1996, requires the 

Environmental Protection Agency (EPA) to make regulatory determinations every five years on at 

least five unregulated contaminants. These unregulated contaminants are chosen from the 

Contaminant Candidate List (CCL), which SDWA requires the agency to publish every five years. In 

order for EPA to make a regulatory determination for a chemical or microbial contaminant, 

adequate data and information must be available on health effects and occurrence, among other 

categories. For contaminants on CCL 3, EPA instituted a systematic process to screen chemicals as 

candidates for regulatory determinations. Many contaminants (e.g., molinate and RDX discussed 

later in this section) were not considered as candidates because, as discussed in the preliminary 

determination (and not disputed by commenters), there were gaps in their health data. The agency 

believes it is important to have a health assessment and develop a health reference level to evaluate 

the occurrence at levels and frequency of public health concern. For information on basis for the 

decision for molinate and RDX, please see the Federal Register Notice for the preliminary regulatory 

determinations (79 FR 62716) and the Protocol for the Regulatory Determination 3 (2014; EPA 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 57 of 67

815-R-14-005). For additional information on the Regulatory Determination 3 process and factors 

considered in evaluating the statutory criteria, refer to section III.A.3 of the Federal Register Notice 

for the preliminary regulatory determinations (79 FR 62716) and the Protocol for the Regulatory 

Determinations 3 (EPA Publication # 815-R14-005; available from www.regulations.gov under 

Docket ID EPA-HQ-OW-2012-0155-0002). 

Individual Comments 

 

Commenter Name: Matthew Corson 

Commenter Organization: American Water 

Letter ID: 0016 

Comment ID: 32145 

Comment Code: 50000 

Comment: * Recommends that EPA make negative regulatory determinations (e.g., no need to 

regulate) for molinate and RDX for lack of occurrence (recognizing that EPA would possibly need 

to open these decisions to further public comment); the lack of a health assessment is irrelevant as 

these contaminants do not occur so they cannot pose a risk to public health

EPA Response: Please see response to comment code 50000 Other contaminants. 

Commenter Name: Emily Krafjack 

Commenter Organization: Connection for Oil, Gas, and Environment in the Northern Tier, Inc. 

(COGENT) 

Letter ID: 0014 

Comment ID: 32151 

Comment Code: 50000 

Comment: Further, we urge the EPA to also consider methane in the same fashion. Methane is 

both naturally occurring and has become an issue with associated gas migration caused by the gas 

industry. 

Thank you for the opportunity to submit comment on this important matter. 

Best Regards, 

Emily E. Krafjack President

EPA Response: Methane is not listed on the CCL 3 and was not considered for RD 3. Please see 

response to comment code 50000 Other contaminants. 

Commenter Name: Thomas W. Curtis 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

Page 58 of 67 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32167 

Comment Code: 50000 

Comment: 3. Recommend the inclusion of two additional negative determinations for molinate and 

RDX in the final; and

EPA Response: Please see response to comment code 50000 Other contaminants. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32169 

Comment Code: 50000 

Comment: AWWA wants to register a separate concern about the lack of progress on microbial 

contaminants through the regulatory development process. This is the third cycle of the 

Contaminant Candidate List (CCL) and Regulatory Determinations processes where the lack of 

progress in fundamental analytical methods development and microbial ecology have prevented any 

meaningful consideration of microbial contaminants in the regulatory development process. AWWA 

strongly recommends that EPA support a systematic, adequately funded, external research agenda to 

develop sufficient science to support risk management decisions for the microbes listed on Third 

CCL. 

If you have any questions about these comments, please feel free to contact myself or Alan 

Roberson in our Washington Office. 

Sincerely, Thomas W. Curtis Deputy Executive Director 

cc: Peter Grevatt – EPA OGWDW Eric Burneson – EPA OGWDW Joyce Donahue – EPA OST 

Suzanne Van Drunick – EPA ORD

EPA Response: Twelve CCL 3 microbes were considered as part of the Regulatory Determination 

3 process. As described in the Protocol document, Appendix D, a variety of considerations 

prevented the 12 from proceeding to Phase 2 of the Regulatory Determinations 3 process. For more 

information please refer to the Protocol (USEPA. 2014. Protocol for the Regulatory Determinations 

3. Including Appendices A-F. April 2014. EPA Publication # 815-R14-005). Within EPA, the 

Drinking Water program collaborates with the Office of Research and Development to 

systematically devise a comprehensive research agenda. In addition, we seek opportunity outside of 

EPA to leverage resources to fill data gaps.

Please see also response to comment code 50000 Other contaminants. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32174 

Comment Code: 50000 

Comment: 3. Recommend the inclusion of two additional negative determinations for Molinate and 

RDX in the final; and

EPA Response: Please see response to comment code 50000 Other contaminants. 

Commenter Name: Thomas W. Curtis 

Commenter Organization: American Water Works Association (AWWA) 

Letter ID: 0017 

Comment ID: 32182 

Comment Code: 50000 

Comment: 3. Negative Determinations for Molinate and RDX 

AWWA recommends adding two more negative determinations for molinate and RDX in the Final 

Third Regulatory Determination, noting that a Notice of Data Availability (NODA) may be needed 

to propose additional preliminary negative determinations. Like the four other negative 

determinations, these two chemicals do not occur nationally - molinate was detected once in the first 

UCMR and RDX was detected three times in UCMR2. In the Federal Register notice, the Agency's 

reasoning for not moving these chemicals from Phase 2 (Data Evaluation) to Phase 3 (Regulatory 

Determination Assessment) was that a health assessment was not completed by fall 2011 (page 

62725 of the Federal Register notice). However, an updated health assessment is irrelevant as a 

negative determination can be made if the chemical does not meet a single SDWA criterion, i.e., 

negligible national occurrence. EPA should not make the absolute minimum number of 

determinations (five) and use the mandated monitoring data for these two chemicals to make two 

additional negative determinations. 

Additionally, a negative determination was made for 1,3-dinitrobenzene based on a 1988 IRIS health 

risk assessment (with some additional data from 1995 from ATSDR to corroborate the risk 

assessment) Therefore, regulating molinate and RDX would not provide a meaningful opportunity 

for risk reduction and these two chemicals should be removed from CCL3 through negative 

regulatory determinations so that these two chemicals do not end up on CCL4 by default. 

A negative determination can be made with an "or" on any of the three SDWA criteria, and these 

two chemicals, like the four proposed, clearly meet EPA's criteria to make a negative determination 

based on negligible national occurrence. EPA should publish a Notice of Data Availability (NODA) 

or additional Preliminary Determinations to include these two additional negative determinations for 

molinate and RDX so that these two chemicals do not end up on CCL4 by default.
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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EPA Response: Please see response to comment code 50000 Other contaminants. 

Commenter Name: James Slotterback, et al. 

Commenter Organization: Responsible Drilling Alliance 

Letter ID: 0021 

Comment ID: 32219 

Comment Code: 50000 

Comment: In addition to strontium, we are concerned about unknown potential effects on fetal 

development from air and water sources of many substances associated with gas development.

EPA Response: Please see response to comment code 50000 Other contaminants. 

Commenter Name: James Slotterback, et al. 

Commenter Organization: Responsible Drilling Alliance 

Letter ID: 0021 

Comment ID: 32222 

Comment Code: 50000 

Comment: The Responsible Drilling Alliance would also like to request that the EPA make a 

determination to regulate methane gas in public water supplies. We see disconcerting levels of 

methane in some baseline testing in this area and have had a number of cases of methane migration 

into private water supplies and public waterways. As determined by the PA DEP, gas development 

has been the cause. We have seen explosive levels of methane in post-drill water tests in multiple 

counties in the shale gas region, including our own. It stands to reason that potentially explosive 

levels of methane in drinking water should be determined prior to any such explosion. 

Our Precautionary Principle guideline leads us to request that the EPA dedicate adequate resources 

to a full study of potential long term impacts on water supplies from the total build-out of shale gas 

development in the many states where it is occurring. 

Thank you for the opportunity to comment. 

Board of Directors, Responsible Drilling Alliance James Slotterback Robert Cross Barbara Jarmoska 

Jennifer Slotterback Roscoe McCloskey Dianne Peeling Mark Szybist

EPA Response: Please see response to comment code 50000 Other contaminants. 

Commenter Name: James Taft 

Commenter Organization: Association of State Drinking Water Administrators (ASDWA) 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Letter ID: 0026 

Comment ID: 32246 

Comment Code: 50000 

Comment: We urge EPA to continue to examine sample results from the previous UCMRs as well 

as UCMR3 to identify other contaminants where the occurrence is zero, or nearly so, and make a 

determination not to regulate, whenever that action can be justified.

EPA Response: Please see responses to comment codes 50000 Other contaminants and 70000 

Comments outside the scope of RD 3. 

Comment Code: 70000 Comments outside the scope of RD 3 

EPA Response to Comment Code 70000: These comments apply to requirements under a 

separate EPA analytical or regulatory process and are outside the scope of the Regulatory 

Determination program. 

Individual Comments 

 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32199 

Comment Code: 70000 

Comment: NRWA's comments on the Preliminary Regulatory Determinations relate to the 

following topics: 

* Urge the Agency to consider including the Arsenic Rule for the Third Six-Year Review considering 

new and evolving science

EPA Response: Please see response to comment code 70000 Comments outside the scope of RD 

3. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32202 

Comment Code: 70000 

Comment: * Concerns about the public notice requirements for detects of unregulated 

contaminants
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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EPA Response: Please see response to comment code 70000 Comments outside the scope of RD 

3. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32204 

Comment Code: 70000 

Comment: Urge the Agency to consider including the Arsenic Rule for the Third Six-Year Review 

considering new and evolving science 

Considering recent peer reviewed arsenic in drinking water health effects studies have advanced our 

understanding of risks to the public of low levels of arsenic in drinking water, EPA should consider 

reviewing the current arsenic standard. The arsenic rule has resulted in hundreds of communities 

moving into non-compliance with federal law and having to pay for new treatment or face civil 

penalties. Many of these communities do not believe this mandated expenditure is in their best 

interest for advancing public health policy. There are still communities out of compliance with the 

current arsenic standard for a fraction of a part per million of naturally occurring arsenic 

concentration in their drinking water. All communities with arsenic in their drinking water 

(compliant and non-complaint communities) would be interested to know the level of arsenic in 

drinking water that is "protective of public health" [42USC30Og-l (b)(l5)(8)1 and does not present 

"an unreasonable risk to health" [42USC300g-5(a)(3)] as intended by the Safe Drinking Water Act. 

Two recently published studies have analyzed the data underlying the Wu et al. (1989) SW Taiwan 

study that is elemental to the current arsenic standard. The new studies specifically examined the low 

dose range data, the behavior of the risk function across the full exposure range, and developed a 

new methodology to examine the transition range between high risk and no risk. The first study 

(Lamm et al. RTP 2013) demonstrates that the finding of a dose-relationship among the low dose 

villages is a consequence of the use of the external reference group that among the low-dose study 

villages there is no positive dose-response. The second study (Lamm et al. Tox 2014 ) demonstrates 

that the data from the high- dose villages show a high cancer risk, but that disappears at 100 ug/L 

and below. The methodologies of the later papers are more refined and should be appreciated by the 

Agency. They demonstrate that extrapolation of the risk found at high doses to lower doses is 

inappropriate and significantly over-predicts the risk in the range of 10-100 ug/L.

* Steven H Lamm; Jun Lu; Shayhan A Robbins; Chao Zhou; Rusan Chen; Manning Feinleib, 

Bladder/lung cancer mortality in Blackfoot-disease (BFD)-endemic area villages with low (<150 

ug/L) well water arsenic levels--an exploration of the dose-response Poisson analysis (Regulatory 

toxicology and pharmacology: RTP 2013;65(1):147-56)

* Steven H. Lamm; Shayhan Robbins; Rusan Chen; Jun Lu; Brian Goodrich, Manning Feinleib, 

Discontinuity in the cancer slope factor as it passes from high to low exposure levels – arsenic in the 

BFD-endemic area (Toxicology 326 (2014) 25–35)
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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EPA Response: Please see response to comment code 70000 Comments outside the scope of RD 

3. 

Commenter Name: Mike Keegan 

Commenter Organization: National Rural Water Association 

Letter ID: 0019 

Comment ID: 32208 

Comment Code: 70000 

Comment: Concerns about the public notice requirements for detects of unregulated contaminants 

Regarding the public notice requirements for communities participating in Unregulated Contaminant 

Monitoring Rule (UCMR) sampling, NRWA urges the Agency to reconsider the current requirement 

that PWSs report UCMR contaminants to the public on CCRs at the minimum reporting level 

(MRL) rather than at occurrences exceeding a conservative health reference level (HRL) or 

maximum contaminant level goal (MCLG). To put this request in context in South Carolina, during 

UCMR3, of the 70 PWSs sampled to date all 70 of the systems had UCMR detections, thus requiring 

public notification. Many of these systems had detects found in each sample at every sampling point 

triggering numerous notifications, thus creating a lengthy CCR, regardless of the absence of 

violations in their routine monitoring and operations. Specific to strontium, of the 70 systems 

sampled, 68 systems had detects of strontium at a range of .31 – 1400 ug/L. Therefore no systems 

detected strontium under UCMR 3 at concentrations above the current HRL of 1500 ug/L, 

however all of these systems were required to report strontium detects on their CCR. 

The following statement was submitted by from Chesterfield County Rural Water (SC), for 

consideration during the recent UCMR forum in June, 2014: 

COMMENTS OF CHARLES GRAY CEO, CHESTERFIELD COUNTY RURAL WATER, 

SOUTH CAROLINA ON BEHALF OF THE SOUTH CAROLINA RURAL WATER 

ASSOCIATION THE NATIONAL RURAL WATER ASSOCIATION U.S. 

ENVIRONMENTAL PROTECTION FORUM ON UNREGULATED CONTAMINANT 

MONITORING RULE (UCMR) JUNE 25, 2014 

Good afternoon, I am Charles Gray, the chief executive office of Chesterfield County Rural Water 

in Chesterfield County in northeastern South Carolina. I appreciate the opportunity that the U.S. 

Environmental Protection has provided to address this forum on Unregulated Contaminant 

Monitoring Rule (UCMR) issues for all small and rural drinking water utilities. I am providing my 

comments on behalf of my water utility, the South Carolina Rural Water Association and the 

National Rural Water Association which represents over 28,000 communities. 

Chesterfield County Rural Water has 900 miles of waterlines with 7,500 customers and additionally 

serves the Towns of Pageland, Chesterfield, Ruby, and Mount Croghan. My utility has conducted 

two rounds of UCMR3 monitoring which was paid for by our state Department of Health & 

Environmental Control (SCDHEC). We found positive detects for the following substances: 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Hexavalent Chromium (.058 – 1.0 ug/l), 1, 4 Dioxane (0.123 – 0.589 ug/l), Strontium (12 – 47 ug/l), 

Vanadium (0.12 - 0.45 ug/l), Chlorate (100 – 130 ug/l) and 1, 1 Dichloroethane (38 – 38 ug/l). 

On behalf of Chesterfield County Rural Water and thousands of other small water utilities, we urge 

the EPA to consider the following questions and modifications to the current and future 

Unregulated Contaminant Monitoring Rules: 

One: These are, by definition, unregulated elements and/or compounds found in water samples. 

The term "contaminant" has a negative connotation for customers, when another, less alarming and 

more accurate term could be used if a utility is going to be required to report findings. 

Two: It is unclear and apparently undefined as to the concentration of the elements or compounds 

that may cause some detrimental impact on public health. As such, it seems reporting these findings 

without clear determination of what accepted levels are considered unsafe concentrations is 

premature and unwarranted. It also leaves the public without the information they most want to 

know; what levels of these substances are safe or not safe. We don't think EPA should override the 

locally preferred public disclosure policy without providing this basic information to the public. 

Three: Utilities were not informed as to how to address customer questions with regard to how any 

of these elements or compounds were determined to make the test list nor what, if any, detrimental 

health consequences might result from positive test results. 

Four: Consumer Confidence Reports are intended to inform the public about the safety of their 

drinking water and system operation. A system can have flawless performance and meet all the 

guidelines of the Safe Drinking Water Act (SDWA), and yet have "hits" on unregulated 

contaminants and appear to consumers that issues exist with system operations. 

Five: Does the SDWA mandate that unregulated contaminants be reported in CCRs? If not, why 

was this required? If this reporting is not required by EPA, water utilities should be allowed to 

publicly disclose the information in a manner more reflective of public health relevance. 

Six: We urge EPA to better inform water utilities as to why these elements/compounds were 

selected and to address customer inquiries and public notifications on CCRs. 

Thank you for your attention and consideration. Small and rural water utilities are eager to 

collaborate with the EPA on improving the current process. We are locally governed by the public 

and want to ensure that federal mandates don't conflict with the public's preferred disclosure 

policies. We appreciate the opportunity to comment today, thank you.

EPA Response: Please see response to comment code 70000 Comments outside the scope of RD 

3. 
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Appendix 1 – Complete List of EPA Comment Codes

Comment 

Code Comment Topics Comment Code Used?

10000 General comments about regulatory determinations Yes

11000 SDWA requirements No

12000 Previous rounds of program (CCL1/RD1, CCL2/RD2, CCL3) No

13000 RD3 Protocol (three-phrase process to narrow down the list of 

CCL3 contaminants) Yes

14000 Drinking Water Strategy (e.g., regulating contaminants in 

groups) No

15000 RD3 communications and outreach Yes

20000 Supporting analyses No

20050 Evaluation of relative source contribution No

21000 Evaluation of adverse health effects (first criterion) Yes

22000 Evaluation of contaminant occurrence (second criterion) Yes

23000 Evaluation of meaningful opportunity for health risk reduction 

(third criterion) No

24000 Evaluation of costs and benefits Yes

30000 The preliminary determinations No

30500 Preliminary determination to not regulate dimethoate, 1,3-

dinitrobenzene, terbufos, and terbufos sulfone Yes

31000 Preliminary determination not to regulate dimethoate No

31100 Background for dimethoate No

31150 Relative source contribution for dimethoate No

31200 Health effects of dimethoate (first criterion) No

31300 Occurrence of dimethoate (second criterion) No

31400 Meaningful opportunity for health risk reduction for dimethoate 

(third criterion) No

32000 Preliminary determination not to regulate 1,3-dinitrobenzene No

32100 Background for 1,3-dinitrobenzene No

32150 Relative source contribution for 1,3-dinitrobenzene No

32200 Health effects of 1,3-dinitrobenzene (first criterion) No

32300 Occurrence of 1,3-dinitrobenzene (second criterion) No

32400 Meaningful opportunity for health risk reduction for 1,3-

dinitrobenzene (third criterion) No

33000 Preliminary determination to regulate strontium Yes
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Comment 

Code Comment Topics Comment Code Used?

33100 Background for strontium No

33150 Relative source contribution for strontium Yes

33200 Health effects of strontium (first criterion) Yes

33300 Occurrence of strontium (second criterion) Yes

33400 Meaningful opportunity for health risk reduction for strontium 

(third criterion) Yes

33500 Costs and benefits of regulating strontium Yes

34000 Preliminary determination not to regulate terbufos and terbufos 

sulfone No

34100 Background for terbufos and terbufos sulfone No

34150 Relative source contribution for terbufos and terbufos sulfone No

34200 Health effects of terbufos and terbufos sulfone (first criterion) No

34300 Occurrence of terbufos and terbufos sulfone (second criterion) No

34400 Meaningful opportunity for health risk reduction for terbufos 

and terbufos sulfone (third criterion) No

40000

EPA's decision to postpone determinations for nitrosamines 

(NDBA, NDEA, NDMA, NDPA, NMEA, NPYR) and 

chlorate

Yes

41000 Nitrosamines Yes

41100 Background for nitrosamines, including formation as DBP No

41150 Relative source contribution for nitrosamines Yes

41200 Health effects of nitrosamines (first criterion) No

41300 Occurrence of nitrosamines (second criterion) No

41400 Meaningful opportunity for health risk reduction for 

nitrosamines (third criterion) Yes

42000 Chlorate No

42100 Background for chlorate, including formation as DBP No

42150 Relative source contribution for chlorate Yes

42200 Health effects of chlorate (first criterion) No

42300 Occurrence of chlorate (second criterion) Yes

42400 Meaningful opportunity for health risk reduction for chlorate 

(third criterion) No

50000 Other contaminants Yes

60000 EPA's next steps and timeline No

61000 Comments about the length of the comment period No

62000 Comments about the December public meeting No
EPA-OGWDW Regulatory Determinations 3 Response to Comments

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Comment 

Code Comment Topics Comment Code Used?

63000 Items for EPA to consider with regard to prospective regulatory 

development for strontium Yes

70000 Comments outside the scope of RegDet 3 Yes