Friday,

July 18, 2003

Part VI

Environmental 

Protection Agency

National Primary Drinking Water 

Regulations; Announcement of 

Completion of EPA’s Review of Existing 

Drinking Water Standards; Notice

42908 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

ENVIRONMENTAL PROTECTION 

AGENCY 

[FRL–7529–1] 

RIN 2040–AD67 

National Primary Drinking Water 

Regulations; Announcement of 

Completion of EPA’s Review of 

Existing Drinking Water Standards

AGENCY: Environmental Protection 

Agency.

ACTION: Notice.

SUMMARY: The Safe Drinking Water Act 

(SDWA) requires the United States 

Environmental Protection Agency (EPA) 

to conduct a periodic review of existing 

National Primary Drinking Water 

Regulations (NPDWRs). EPA has 

completed its review of 69 NPDWRs 

that were established prior to 1997, 

including 68 chemical NPDWRs and the 

Total Coliform Rule (TCR). The 

intended purpose of the review was to 

identify those NPDWRs for which 

current health risk assessments, changes 

in technology, and/or other factors, 

provide a health or technological basis 

to support a regulatory revision that will 

maintain or improve public health 

protection. 

EPA published its protocol for the 

review of NPDWRs and its preliminary 

revise/not revise decisions for the 69 

NPDWRs in the April 17, 2002, edition 

of the Federal Register (67 FR 19030 

(USEPA, 2002g)) in order to seek 

comment from the public. Today’s 

action briefly describes the major 

comments, other new information, and 

EPA’s current revise/not revise 

decisions for the 69 NPDWRs.

ADDRESSES: The official public docket 

for this action is located at EPA West 

Building, Room B102, 1301 Constitution 

Avenue, NW., Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Contact: Ken Rotert, (202) 564–5280,

e-mail: rotert.kenneth@epa.gov for 

inquiries regarding the TCR. For all 

other technical inquiries contact: Judy 

Lebowich, (202) 564–4884, e-mail: 

lebowich.judy@epa.gov, or Wynne 

Miller, (202) 564–4887, e-mail: 

miller.wynne@epa.gov. General 

information may also be obtained from 

the EPA Safe Drinking Water Hotline. 

Callers within the United States may 

reach the Hotline at (800) 426–4791. 

The Hotline is open Monday through 

Friday, excluding Federal holidays, 

from 9 a.m. to 5:30 p.m. Eastern Time.

SUPPLEMENTARY INFORMATION:

Table of Contents 

I. General Information 

A. Does this Notice Apply to My Public 

Water System? 

B. How Can I Get Copies of Related 

Information? 

1. Docket 

2. Electronic Access

II. Background 

A. What Is the Statutory Requirement for 

the Six-Year Review? 

B. What Has the Agency Done to Address 

the Statutory Requirement? 

III. EPA’s Current Revise/Not Revise 

Decisions for the 69 Pre-1997 NPDWRs 

IV. Summary of Major Comments and New 

Information and the Agency’s Response 

A. What Did Commenters Say Regarding 

the Reasonableness and Appropriateness 

of EPA’s Six-Year Review Approach? 

1. Overall Approach and Decision Criteria 

2. Health Effects Technical Review 

3. Analytical Methods Feasibility 

Technical Review 

4. Review of Treatment Technologies and 

Related Issues 

5. Review of Implementation-Related 

Issues 

6. Review of Occurrence and Exposure 

7. Consideration of Available Economic 

Information 

B. What Comments or New Information 

Did EPA Receive on Chemical 

Contaminant-Specific Issues? 

1. Alachlor 

2. Antimony 

3. Atrazine 

4. Beryllium 

5. Carbofuran 

6. Chromium 

7. 1,1-Dichloroethylene 

8. Dichloromethane 

9. Di(2-ethylhexyl)adipate (DEHA) 

10. Di(2-ethylhexyl)phthalate (DEHP) 

11. Fluoride 

12. Glyphosate 

13. Lead and Copper 

14. Lindane (g-hexachlorocyclohexane) 

15. Simazine 

C. What Comments Did EPA Receive 

Regarding the Review of 

Implementation-Related Issues for 

Chemical NPDWRs? 

D. What Comments Did EPA Receive on 

the Total Coliform Rule? 

E. What Comments Did EPA Receive on 

Research Needs? 

V. References 

List of Tables 

Table III–1: Current Revise/Not Revise 

Decisions for the 68 Chemical NPDWRs 

and the TCR 

Table IV–1: 1,1-Dichloroethylene Occurrence 

Table IV–2: Lindane Occurrence

I. General Information 

A. Does This Notice Apply to My Public 

Water System? 

This action itself does not impose any 

requirements on anyone. Instead, it 

notifies interested parties of the 

availability of EPA’s responses to 

comments received on EPA’s Six-Year 

Review protocol and the Agency’s 

current revise/not revise decisions for 

69 NPDWRs. 

B. How Can I Get Copies of Related 

Information? 

1. Docket 

EPA has established an official public 

docket for this action under Docket ID 

No. OW–2002–0012. The official public 

docket consists of the documents 

specifically referenced in this action, 

any public comments received, and 

other information related to this action. 

Although a part of the official docket, 

the public docket does not include 

Confidential Business Information (CBI) 

or other information whose disclosure is 

restricted by statute. The official public 

docket is the collection of materials that 

is available for public viewing at the 

Water Docket in the EPA Docket Center, 

(EPA/DC) EPA West, Room B102, 1301 

Constitution Ave., NW., Washington, 

DC. The EPA Docket Center Public 

Reading Room is open from 8:30 a.m. to 

4:30 p.m., Monday through Friday, 

excluding legal holidays. The telephone 

number for the Public Reading Room is 

(202) 566–1744, and the telephone 

number for the Water Docket is (202) 

566–2426. 

2. Electronic Access 

You may access this Federal Register

document electronically through the 

EPA Internet under the ‘‘Federal 

Register’’ listings at http://

www.epa.gov/fedrgstr/.

An electronic version of the public 

docket is available through EPA’s 

electronic public docket and comment 

system, EPA Dockets. You may use EPA 

Dockets at http://www.epa.gov/edocket/

to view public comments, access the 

index listing of the contents of the 

official public docket, and access those 

documents in the public docket that are 

available electronically. Although not 

all docket materials may be available 

electronically, you may still access any 

of the publicly available docket 

materials through the docket facility 

identified in section I.B.1. Once in the 

system, select ‘‘search,’’ then key in the 

appropriate docket identification 

number. 

Abbreviations and Acronyms Used in 

This Action 

BAT—best available technology 

CBI—confidential business information 

CCL—contaminant candidate list 

CFR—Code of Federal Regulations 

CMR—Chemical Monitoring Reform 

DACT—diaminochlorotriazine 

DEA—desethyl atrazine 

DEHA—di(2-ethylhexyl)adipate 

DEHP—di(2-ethylhexyl)phthalate 

DIA—desisopropyl atrazine 

EPA—United States Environmental 

Protection Agency

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42909

1These include: (1) EPA’s overall protocol for the 

review of NPDWRs (USEPA, 2003c); (2) health 

effects (USEPA, 2003f); (3) analytical methods 

feasibility (USEPA, 2003a); (4) treatment technology 

(USEPA, 2003g); (5) consideration of other 

regulatory revisions (USEPA, 2003b); (6) occurrence 

and exposure (USEPA, 2003d; USEPA, 2002f); (7) 

and economic considerations (USEPA, 2002c).

EPA/DC—EPA Docket Center

FQPA—Food Quality Protection Act 

FR—Federal Register

IOC—inorganic chemical 

IRED—interim reregistration eligibility 

decision 

IRIS—Integrated Risk Information 

System 

LCCA—Lead Contamination Control Act 

of 1988 

LCR—Lead and Copper Rule 

MCL—maximum contaminant level 

MCLG—maximum contaminant level 

goal 

MDL—method detection limit 

mg/kg/day—milligram(s) per kilogram 

of body weight per day 

mg/L—milligram(s) per liter 

MYP—multi-year plan 

NAS—National Academy of Sciences 

NCOD—National Contaminant 

Occurrence Database 

NDWAC—National Drinking Water 

Advisory Council 

NPDWR—National Primary Drinking 

Water Regulation 

NRC—National Research Council 

NTP—National Toxicology Program 

NTNCWS—non-transient noncommunity water system 

Occurrence Methodology Document—

Occurrence Estimation Methodology 

and Occurrence Findings Report for 

the Six-Year Review of Existing 

National Primary Drinking Water 

Regulations 

Occurrence Summary Document—

Occurrence Summary and Use 

Support Document for the Six-Year 

Review of Existing National Primary 

Drinking Water Regulations 

OPP—Office of Pesticide Programs 

OW—Office of Water 

PE—performance evaluation 

PHS—Public Health Service 

PQL—practical quantitation level 

Protocol Document—EPA Protocol for 

Review of Existing National Primary 

Drinking Water Regulations 

RED—reregistration eligibility decision 

RfD—reference dose 

ROS—regression on ordered statistics 

RSC—relative source contribution 

SAB—Science Advisory Board 

SAP—Science Advisory Panel 

SDWA—Safe Drinking Water Act 

SOC—synthetic organic chemical 

TCR—Total Coliform Rule 

TMDLs—total maximum daily loads 

Treatment Feasibility Document—Water 

Treatment Technology Feasibility 

Support Document for Chemical 

Contaminants; In Support of EPA SixYear Review of National Primary 

Drinking Water Regulations 

TT—treatment technique 

VOC—volatile organic chemical 

WQP—water quality parameter 

WS—water supply 

II. Background 

A. What Is the Statutory Requirement 

for the Six-Year Review? 

Under the Safe Drinking Water Act 

(SDWA), as amended in 1996, EPA must 

periodically review existing National 

Primary Drinking Water Regulations 

(NPDWRs) and, if appropriate, revise 

them. Section 1412(b)(9) of SDWA 

states:

The Administrator shall, not less often 

than every 6 years, review and revise, as 

appropriate, each national primary drinking 

water regulation promulgated under this title. 

Any revision of a national primary drinking 

water regulation shall be promulgated in 

accordance with this section, except that 

each revision shall maintain, or provide for 

greater, protection of the health of persons.

B. What Has the Agency Done To 

Address the Statutory Requirement? 

The Agency developed a systematic 

process, or protocol, for the review of 

existing NPDWRs in accordance with 

the SDWA requirements and applied the 

protocol to the review of the NPDWRs 

for total coliforms and 68 inorganic and 

organic chemicals published prior to the 

SDWA 1996 Amendments (i.e., pre-1997 

NPDWRs). In the April 17, 2002, 

Federal Register, EPA provided: 

• A description of the review 

protocol; 

• A detailed discussion of how the 

protocol was applied in assessing each 

of the 69 pre-1997 NPDWRs; 

• The preliminary results of each of 

the technical reviews, and the 

preliminary decision for each NPDWR; 

and 

• A request for the public to comment 

on any aspect of the Agency’s protocol 

and preliminary decisions. 

Please refer to the April 17, 2002, 

Federal Register for the detailed 

discussion of EPA’s revise/not revise 

decisions for each of the 69 NPDWRs. 

Today’s action briefly summarizes the 

major public comments, other new 

information, and EPA’s current revise/

not revise decisions for the 69 NPDWRs. 

Today’s action only discusses in detail 

those decisions or rationales that were 

affected by public comments or other 

new information that has become 

available since April 2002. 

In June 2002, EPA consulted with the 

Science Advisory Board (SAB) Drinking 

Water Committee and requested their 

review and comment on whether the 

protocol EPA developed based on the 

National Drinking Water Advisory 

Council (NDWAC) recommendations 

was consistently applied and 

appropriately documented. The SAB 

provided verbal feedback regarding the 

transparency and clarity of EPA’s 

decision criteria for making its revise/

not revise decisions under the current 

review. EPA has revised this protocol 

document to better explain how the 

decision criteria were applied and will 

also take the SAB comments into 

consideration when planning for the 

next review cycle.

III. EPA’s Current Revise/Not Revise 

Decisions for the 69 Pre-1997 NPDWRs 

EPA received comments from 44 

commenters on its preliminary revise/

not revise decisions in the April 17, 

2002, Federal Register. The Agency 

responded to these comments in the 

‘‘Public Comment and Response 

Summary for the Six-Year Review of 

National Primary Drinking Water 

Regulations’’ (USEPA, 2003e), which is 

available in the Water Docket in the 

EPA Docket Center and at the EPA 

Dockets Web site http://www.epa.gov/

epadocket/. Other technical support 

documents 1 for the decisions discussed 

in today’s action are also available in 

the Water Docket and at the EPA 

Dockets Web site http://www.epa.gov/

epadocket/ and the Safewater Web site 

http://www.epa.gov/safewater/.

Based on the Agency’s preliminary 

review, as well as the public comments 

received and other new information, 

EPA believes that it is appropriate to 

revise the Total Coliform Rule (TCR). 

The Agency also believes that it is not 

appropriate to revise the 68 chemical 

NPDWRs at this time. However, for the 

reasons discussed in sections IV.B.7, 

IV.B.13, and IV.B.14 of today’s action, 

the Agency has modified the basis of its 

not revise findings for 1,1-

dichloroethylene, lead, and lindane, 

respectively. Table III–1 reflects the 

Agency’s current revise/not revise 

decisions for the 69 NPDWRs. As 

indicated in Table III–1, EPA’s decision 

not to revise an NPDWR at this time is 

based on one of the following reasons: 

• Health risk assessment is in 

process: As of December 31, 2002, the 

Agency is currently conducting, or has 

scheduled, a detailed review of current 

health effects information. Because the 

results of the assessment are not yet 

available, or were not available in time 

for consideration under the 1996–2002 

review cycle, the Agency does not 

believe it is appropriate to revise the 

NPDWR at this time. In these cases, EPA 

will consider the results of the updated

42910 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

health risk assessment during the 2002–

2008 review cycle. If the results of the 

health risk assessment indicate a 

compelling reason to reconsider the 

maximum contaminant level goal 

(MCLG), EPA may decide to accelerate 

the review schedule for that 

contaminant’s NPDWR. 

• NPDWR remains appropriate after 

data/information review: The outcome 

of the review indicates that the current 

regulatory requirements remain 

appropriate, and therefore, no regulatory 

revisions are warranted. Any new 

information available to the Agency 

either supports the current regulatory 

requirements or does not justify a 

revision. 

• New information, but no revision 

appropriate at this time because:

—Low priority: In EPA’s judgment, any 

resulting revisions to the NPDWR 

would not provide a meaningful 

opportunity for health risk reduction 

or result in meaningful cost-savings to 

public water systems and their 

customers. These revisions are a low 

priority activity for the Agency and, 

thus, are not appropriate for revision 

at this time because of one or more of 

the following considerations: 

competing workload priorities; the 

administrative costs associated with 

rulemaking; and the burden on States 

and the regulated community to 

implement any regulatory change that 

resulted. 

—Information gaps: Although results of 

the review support consideration of a 

possible revision, the available data 

are insufficient to support a definitive 

regulatory decision at this time. 

BILLING CODE 6560–50–P

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42911

BILLING CODE 6560–50–C


EN18JY03.070</GPH>
42912 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

IV. Summary of Major Comments and 

New Information and the Agency’s 

Response 

This section summarizes the major 

public comments, including the 

Agency’s response, and other new 

information, and explains any 

modifications to EPA’s preliminary 

revise/not revise decisions. For a more 

detailed summary of the comments and 

the Agency’s response, please refer to 

the document: ‘‘Public Comment and 

Response Summary for the Six-Year 

Review of National Primary Drinking 

Water Regulation’’ (USEPA, 2003e). 

A. What Did Commenters Say Regarding 

the Reasonableness and 

Appropriateness of EPA’s Six-Year 

Review Approach? 

1. Overall Approach and Decision 

Criteria 

a. Adequacy of the Review.

Commenters generally agreed that EPA 

had identified the appropriate key 

elements of the review. However, some 

commenters stated that the Agency 

could have done more in some areas 

(e.g., implementation) and a few 

commenters expressed the opinion that 

the Agency’s review process contains 

weaknesses, or was not applied 

appropriately, because it did not 

identify any chemical NPDWRs for 

revision at this time. 

EPA Response: The Agency believes 

that its basic review protocol and 

decision rationale are reasonable and 

appropriate. Even though EPA’s 

application of the protocol did not 

identify any chemical NPDWRs for 

revision at this time, that is not a reason 

to reject or modify the protocol. The 

review did result in the initiation of 

health risk assessments for three 

contaminants and efforts to address data 

gaps/research needs for several other 

contaminants. Health risk assessments 

are underway for approximately half of 

the chemical contaminants addressed in 

today’s action. The Agency expects most 

of these assessments to be completed 

within the next few years. When 

completed, these assessments will 

support further analysis that may result 

in different revise/not revise decisions 

as part of the ongoing Six-Year Review 

process. 

b. Criteria for Deciding that an MCLG/

MCL Revision is Appropriate and 

Definition of ‘‘Significant’’ and 

‘‘Negligible.’’ While some commenters 

agreed, others disagreed with the 

Agency’s consideration of estimated 

changes in occurrence levels and 

available economic information 

whenever a health or technological basis 

exists to revise a standard. For example, 

some commenters felt that EPA should 

revise the MCLG and, as appropriate, 

the maximum contaminant level (MCL), 

whenever a health basis exists, 

regardless of other considerations. A 

few commenters criticized the Agency 

for not defining what it considers 

‘‘significant’’ and ‘‘negligible’’ gains in 

public health protection and/or costsavings in terms of regulatory revision. 

EPA Response: Section 1412(b)(9) of 

SDWA, as amended in 1996, provides 

the Administrator with broad discretion 

to determine when a revision to an 

NPDWR is appropriate. As a part of this 

determination, the Agency believes it is 

reasonable to consider whether a 

potential revision is likely to provide a 

meaningful opportunity for health risk 

reduction. This criterion is consistent 

with the statutory provisions governing 

the regulatory determination process 

under section 1412(b)(1)(A) for 

contaminants not currently regulated. 

EPA also believes it is reasonable to 

consider the extent of potential costsavings for public water systems and 

their customers when determining 

whether revisions that potentially 

would result in a relaxed standard (i.e.,

where a health basis exists for a less 

stringent standard) or streamlined 

implementation are appropriate. These 

considerations allow the Administrator 

to better prioritize efforts that are most 

likely to result in a meaningful 

opportunity for health risk reduction or 

cost-savings to public water systems and 

their customers. Revisions that do not 

satisfy at least one of these criteria are 

a low priority activity for the Agency, 

and thus are not appropriate at this time 

because of one or more of the following 

considerations: 

• Competing workload priorities; 

• The administrative costs associated 

with rulemaking; and 

• The burden on States and the 

regulated community to implement any 

regulatory change that resulted. 

EPA believes that the determination 

of whether the impact of a potential 

revision is ‘‘significant’’ or ‘‘negligible’’

is a matter of judgment that depends on 

a number of variables, not all of which 

are amenable to precise definition. 

However, EPA recognizes that the use of 

‘‘negligible/significant’’ terminology 

may imply more precision and 

quantitation in the determination than 

is possible. The Agency also 

understands that the use of the term 

‘‘negligible’’ may imply to some that the 

Agency is belittling small gains in 

health risk reduction. This is not the 

Agency’s intent. Accordingly, in today’s 

action, the Agency has explained its 

rationale more clearly in terms of the 

criteria noted in the previous paragraph. 

c. Authority to Relax an Existing 

Standard and Deregulation of Low/NonOccurring Contaminants. Some 

commenters argued that the Agency 

should never consider relaxing a 

standard because doing so, by 

definition, would lessen the level of 

public health protection. Other 

commenters encouraged the Agency to 

actively consider deregulating 

contaminants that have low occurrence 

or do not appear to be occurring in 

finished water or, at a minimum, to 

further reduce the frequency of 

monitoring for these contaminants.

EPA Response: EPA disagrees with 

those commenters who oppose relaxing 

a standard for any reason. The 

legislative history of the SDWA 

Amendments of 1996 makes clear that 

Congress envisioned the possibility that 

a relaxed standard might be appropriate 

under circumstances that would not 

result in a lessening of the level of 

public health protection. In its 

discussion of potential revisions to an 

existing drinking water standard, Senate 

Report Number 104–169 (available 

electronically at http://thomas.loc.gov/) 

states:

Amendments made by the bill require that 

any future standard issued for a contaminant 

already regulated must maintain or provide 

for greater protection of the health of persons. 

Generally, this will preclude the 

promulgation of a revised standard for a 

contaminant that is less stringent than the 

standard already in place. However, there are 

circumstances under which a standard may 

be relaxed. The maximum contaminant level 

goal for a contaminant is set at a level at 

which there is no adverse effect on the health 

of persons with an adequate margin of safety. 

New scientific information may cause the 

MCLG to be revised and in some cases these 

revisions may be to less stringent levels. This 

may lead to a revision of the maximum 

contaminant level since it need be no more 

stringent than the MCLG. New information 

may also allow for a smaller margin of safety 

because it narrows the range of uncertainty 

for estimates of health risks. Finally, some 

substances which have been regulated as 

carcinogens for ingestion in drinking water 

may be reclassified (as asbestos has been in 

the most recent revision) or assigned a 

threshold for the effect based on new 

scientific information. In each of these cases, 

EPA may issue a revised standard for a 

contaminant that is less stringent than the 

one it replaces.

(S. Rep.104–169, 104th Cong., 1st Sess. 

(1995) at 38)

However, because section 1412(b)(9) 

of SDWA requires that any revision to 

an existing NPDWR maintain or 

improve the level of public health 

protection, EPA believes that a clear, 

technically-based demonstration

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42913

regarding the absence of potential risk is 

necessary to deregulate a contaminant. 

EPA does not believe it is appropriate to 

deregulate any currently regulated 

contaminant at this time because the 

Agency is not able to make a 

determination, pursuant to section 

1412(b)(9) of SDWA, that there would 

be no lessening of public health 

protection if the contaminant were 

deregulated. The Agency disagrees that 

evaluation of finished water data is 

sufficient to consider deregulation of 

low or non-occurring contaminants. The 

apparent low or non-occurrence of these 

contaminants in finished water may be 

the result of effective treatment 

processes in place rather than the lack 

of occurrence in source water. 

EPA believes that the existing waiver 

provisions in the SDWA regulations 

give States sufficient flexibility to 

reduce or potentially eliminate 

monitoring of a chemical contaminant, 

where appropriate. States that have 

primacy for the drinking water 

regulations are responsible for their 

waiver programs and can grant waivers 

if a particular pesticide or herbicide has 

not been previously used, 

manufactured, stored, transported, or 

disposed in the area, a system’s source 

water is not susceptible to 

contamination from the chemical, or the 

State has determined the system is not 

vulnerable. The State can grant waivers 

for individual contaminants, a group of 

contaminants, or issue an area-wide 

waiver (see 40 CFR 141.23 (b) and (c), 

and 141.24 (f) and (h)). In addition, 

States can adopt alternative monitoring 

strategies as long as the approach is as 

stringent as the Federal requirements 

(USEPA, 1997b). 

2. Health Effects Technical Review 

a. Contaminants Undergoing Health 

Risk Assessments. A few commenters 

raised issues with respect to the 36 

chemical contaminants for which health 

risk assessments were underway when 

EPA published its preliminary revise/

not revise decisions in the April 17, 

2002, Federal Register. In particular, 

these commenters wanted to know the 

process that EPA plans to follow to 

review each NPDWR once the risk 

assessment is completed, including 

when that review would occur and 

when an accelerated review would be 

appropriate. 

EPA Response: Between April and 

August 2002, the Agency completed 

health risk assessments for 2 of the 36 

contaminants: 1,1-dichloroethylene and 

lindane. The results of those 

assessments and the impact on the 

Agency’s revise/not revise decisions are 

discussed in sections IV.B.7 and 

IV.B.14, respectively, of today’s action. 

NPDWRs for the remaining 

contaminants for which health risk 

assessments are in process will be 

reviewed as a part of the 2002–2008 

review cycle. However, if in the 

Agency’s judgment, a compelling reason 

exists to revisit the ‘‘not revise’’

decision sooner, EPA may accelerate the 

review cycle for that NPDWR. In 

reviewing these regulations, EPA 

expects to apply an approach consistent 

with the protocol used for the current 

review. That is, the Agency will 

consider the same key elements and 

apply the same basic decision tree for 

making a revise/not revise decision. The 

key elements of the review include 

health effects technical review, 

technology review, other regulatory 

revisions review, and, if appropriate, 

occurrence/exposure analyses and 

consideration of available economic 

information (see 67 FR 19030 at 19038, 

April 17, 2002 (USEPA, 2002g)). 

b. Other Issues Related to the Health 

Effects Technical Review. One 

commenter stated that the Agency risk 

assessments underestimate risk because 

absorption of chemicals through the 

skin, lung, and nose is not ‘‘adequately’’

taken into account. Another commenter 

encouraged the Agency to evaluate the 

literature for potential reproductive and 

developmental effects for chemicals 

with zero MCLGs since risk 

management strategies, such as 

monitoring frequency or treatment 

requirements, may be affected by such 

information.

EPA Response: EPA disagrees that the 

Agency underestimates risk when 

deriving MCLGs. The Agency takes 

multiple routes of exposure into account 

by including a relative source 

contribution (RSC) in its calculation of 

an MCLG value. The RSC compares 

exposure from air, food, and drinking 

water and uses the data in allocating a 

portion of the total exposure to drinking 

water. When exposure data for the 

chemical are not available, EPA assumes 

that the RSC from drinking water is 20 

percent of the total exposure. This 

allows 80 percent of the total exposure 

to come from sources other than 

drinking water, such as exposure from 

food, inhalation, or dermal contact. 

EPA recognizes the possibility that 

some chemicals with zero MCLGs may 

also be of reproductive and/or 

developmental concern. EPA is 

investigating these endpoints and their 

potential impact on monitoring 

frequency or treatment requirements. 

However, the Agency does not believe 

the analysis can be completed during 

the current review cycle without 

significantly delaying the current revise/

not revise decisions. To the extent 

possible, EPA will consider the results 

of this analysis and any additional 

information during subsequent Six-Year 

Reviews. 

3. Analytical Methods Feasibility 

Technical Review 

Commenters generally supported the 

Agency’s approach of using 

Performance Evaluation (PE) Water 

Supply (WS) data and the 10 times 

method detection limit (MDL) 

multiplier to evaluate possible changes 

in analytical feasibility for several of the 

contaminants under this Six-Year 

Review. A few commenters agreed that 

the WS data are a valuable source of 

information for evaluating 

interlaboratory performance and for 

developing practical quantitation levels 

(PQLs). However, the same commenters 

questioned whether the approach of 

using PE WS data will be possible for 

future reviews since the Agency’s 

laboratory certification program that 

once collected this information has been 

externalized to private providers. These 

commenters questioned whether the 

externalized or privatized data would be 

sufficient for the determination and/or 

re-evaluation of PQLs. In addition, at 

least one commenter suggested that it 

may be appropriate (in the next Six-Year 

Review) to re-evaluate the policy of 

basing the PQL on only EPA Regional 

and State laboratory results, and 

recommended that the Agency include 

commercial and large utility laboratory 

results. According to the commenter, 

these laboratories (commercial and large 

utility) have demonstrated ‘‘significant 

innovation in method development and 

improved quantitation.’’

EPA Response: EPA agrees that the 

WS studies have been a valuable source 

of information for determining PQLs. At 

this time, the Agency has not 

determined whether the privatized data 

will be sufficient for the purposes 

mentioned by the commenter. In 

addition, the Agency has not yet 

determined how best to gather data to 

determine and/or reassess PQLs for 

future reviews. The Agency is in the 

process of evaluating acceptable 

options. The policy for determining the 

most appropriate methodology for 

calculating PQLs for drinking water 

contaminants is outside the scope of the 

Six-Year Review. 

4. Review of Treatment Technologies 

and Related Issues 

Commenters suggested that, while 

EPA’s review of existing NPDWRs was 

generally consistent with the NDWAC 

recommendations to EPA (NDWAC, 

2000), the Agency’s review of treatment

42914 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

technologies which support the 

regulations should be expanded. 

Specifically, commenters recommended 

that EPA review all treatment technique 

(TT) requirements and allow for 

changing or expanding these TT 

requirements where new information 

warrants such a change. 

EPA Response: EPA continues to 

believe its approach to reviewing TT 

requirements is appropriate. The ‘‘EPA 

Protocol for the Review of Existing 

NPDWRs’’ (Protocol Document) 

discusses when it is appropriate for the 

Agency to consider revisions to TT-type 

regulations (see sections II.C and III.B of 

the Protocol documents) (USEPA, 

2002d; USEPA, 2003c). The Agency 

discussed the review of the four 

chemical treatment technique NPDWRs 

(i.e., acrylamide, copper, 

epichlorohydrin, and lead) in both the 

draft and final ‘‘Water Treatment 

Technology Feasibility Support 

Document for Chemical Contaminants; 

In Support of EPA Six-Year Review of 

National Primary Drinking Water 

Regulations’’ (Treatment Feasibility 

Documents) (USEPA, 2002b; USEPA, 

2003g). The Agency has no specific 

information that provides a basis for 

revisions to TT requirements at this 

time. However, EPA believes that 

research data in a number of treatmentrelated areas may be useful in future 

reviews of NPDWRs. The Agency is 

committed to working with stakeholders 

to identify and prioritize treatmentrelated research needs, and to work with 

EPA’s research partners to address the 

highest priority needs. 

5. Review of Implementation-Related 

Issues 

While several commenters felt overall 

that EPA’s Six-Year Review protocol 

was reasonable and appropriate, they 

encouraged EPA to consider 

implementation-related modifications 

(i.e., ‘‘other regulatory revisions’’) as a 

reason to revise a rule, even if there 

were no basis to revise the MCLG and/

or MCL/TT requirements. 

EPA Response: Implementationrelated issues are the primary reason for 

the Agency’s decision to revise the TCR 

at this time (67 FR 19030 at 19085, April 

17, 2002 (USEPA, 2002g)), so it is clear 

that EPA considered implementedrelated issues in its review. The Protocol 

Document (USEPA, 2002d; USEPA, 

2003c) identifies the conditions under 

which the Agency will consider 

implementation-related revisions. EPA 

continues to believe these criteria are 

appropriate. During the current review, 

none of the identified potential 

implementation-related revisions 

pertaining to the chemical NPDWRs, in 

EPA’s judgment, met the stated criteria 

for reasons documented in EPA’s final 

document, ‘‘Consideration of Other 

Regulatory Revisions for Chemical 

Contaminants in Support of the SixYear Review of National Primary 

Drinking Water Regulations’’ (USEPA, 

2003b). 

6. Review of Occurrence and Exposure 

a. Occurrence Database Concerns. A 

few commenters asked for information 

regarding next steps for the National 

Contaminant Occurrence Database 

(NCOD). Another commenter pointed 

out that States have been willing to 

assist EPA by providing occurrence data 

beyond what is required of them. 

However, the commenter raised 

concerns that he/she felt EPA needs to 

address to facilitate further data sharing. 

Some commenters expressed concern 

about the completeness and 

representativeness of the 16-State data 

set used for the Six-Year Review. One 

commenter suggested that the Agency 

should have issued an Information 

Collection Request to obtain more 

complete data for the Six-Year Review 

analysis.

EPA Response: The Agency is 

updating the NCOD to provide sample 

data that have been quality checked and 

used in various EPA analyses. This 

update to NCOD includes unregulated 

occurrence data collected prior to 1999 

as well as the latest Unregulated 

Contaminant Monitoring Rule data (64 

FR 50556, September 17, 1999 (USEPA, 

1999b)) reported by laboratories for 

public water systems required to report 

results. It also includes the data used for 

the Six-Year Review of regulated 

contaminants. EPA appreciates that 

some States are willing to share their 

full compliance monitoring records with 

the Agency, even though it is not 

required. The Agency and the States are 

continuing to work together to establish 

a protocol for data sharing, including 

safeguards to prevent misuse and 

misinterpretation of data. 

The 16-State cross-section data set 

compiled for occurrence analyses for the 

Six-Year Review is the largest 

compliance monitoring data set for 

drinking water assembled by EPA to 

date. The design and construction of the 

16-State cross-section data set was based 

on the fact that contaminant occurrence 

varies spatially (geographically) due to 

differing patterns of population, land 

use, chemical use, geology, hydrology, 

and climate. The detailed description of 

the ‘‘pollution-potential’’ and 

geographic diversity considerations, and 

the derived balanced cross-section of 

States (that was developed to be 

collectively indicative of national 

occurrence) is included in the 

‘‘Occurrence Estimation Methodology 

and Occurrence Findings Report for the 

Six-Year Review of Existing National 

Primary Drinking Water Regulations’’

(Occurrence Methodology Document) 

(USEPA, 2003d). EPA selected its 16-

State cross-section to be as 

representative as possible of national 

contaminant occurrence. In EPA’s 

judgment, these States provide a 

reasonable cross-section of agricultural 

and industrial pollution potential, as 

described in the Occurrence 

Methodology Document, and also 

provide geographic coverage of the 

United States. Therefore, EPA believes 

that the data assembled from these 

States is the most representative data 

currently available of national 

contaminant occurrence. 

The Agency did receive occurrence 

data from States other than those in its 

16-State cross-section. However, many 

State data sets contained incomplete 

records (e.g., no water type or 

population records specified) or had 

other quality problems. Therefore, they 

were not included in the analyzed data 

set. 

b. Occurrence Analysis Methodology.

One commenter noted that while the 

occurrence estimation methodology has 

several strengths, it also has a number 

of flaws. The commenter was concerned 

about the large proportion of nondetected observations in the occurrence 

data, and the difficulty of verifying the 

assumptions made by the Agency. The 

commenter agreed that EPA’s 

occurrence analysis may represent a 

‘‘decent’’ estimate given the limitations 

of the data. The commenter also noted 

that the occurrence estimation 

methodology is premised on ‘‘subjective 

decisions or qualitative observations 

* * * rather than documented, 

statistically-based quantitative ones’’

and would like to have seen alternate 

approaches used to provide 

confirmation of the estimates. In 

addition, the commenter questioned 

why the Agency used ‘‘modeled data 

sets to test the model rather than a 

standard statistical strategy of basing the 

model on a portion of the data set and 

using the remainder to test the model.’’

One commenter stated that the Stage 

2 analysis (Bayesian analysis) was 

poorly described and that this conflicts 

with the transparency requirements of 

the 1996 SDWA Amendments. In 

addition, the commenter asked EPA to 

clarify how the occurrence data from 

other survey efforts, which are 

summarized in ‘‘Occurrence Summary 

and Use Support Document for the SixYear Review of Existing National 

Primary Drinking Water Regulations’’

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42915

(Occurrence Summary Document) 

(USEPA, 2002f), were used to inform the 

modeling effort. 

EPA Response: EPA’s occurrence 

model development work was 

significantly revised to reflect peer 

review comments prior to the March 

2002 Occurrence Methodology 

Document (USEPA, 2002e) and the 

April 17, 2002, Federal Register. The 

additional work involved the 

development of a detailed simulation 

study to evaluate the Bayesian model. 

EPA evaluated the performance of the 

Bayesian estimator and an alternative 

occurrence estimation approach, the 

Regression on Ordered Statistics (ROS) 

method, against synthetic data (i.e., data 

developed with known national 

contaminant occurrence distributions). 

This simulation study also enabled an 

explicit evaluation of the validity of the 

assumption of a log-normal distribution 

of the data. 

The simulation study was conducted 

using varying conditions of a correctly 

and incorrectly specified model, and 

synthetic data sets developed with high 

and low amounts of non-detected data. 

The study findings indicated that the 

Bayesian estimator performed well at 

estimating the distributions of 

contaminant concentration means 

(especially in the upper tails), 

performed better than the alternate 

approach (i.e., the ROS method), and 

accurately estimated the uncertainty of 

the distributional estimates. The Agency 

believes that this analysis supports the 

validity of EPA’s analytical approach. 

The Bayesian model was tested against 

the ROS approach because the ROS 

method is an accepted drinking water 

contaminant occurrence estimation 

approach and was used to estimate 

occurrence for the recent arsenic rule. 

These findings were all included and 

described in the Six-Year Review’s 

Occurrence Methodology Document.

EPA has attempted to make its 

occurrence analysis as clear as possible. 

In response to the concerns raised by 

the peer reviewers, a less technical 

description of the occurrence estimation 

methodology, aimed at the general 

reader, was added to the main body of 

the document. A detailed description of 

the analysis, intended for readers with 

technical expertise, including the 

complete computer code used for model 

analysis, was incorporated into an 

appendix of the document. EPA agrees 

that its estimation methodology is 

complex, but also believes that it is as 

transparent as possible while still 

providing a technically accurate 

description of the Agency’s analysis. 

The use of simple national occurrence 

(statistical) assessments is not possible 

at this time because there is no national 

database with a complete collection of 

regulated contaminant occurrence data. 

Thus, there is no ideal basis for 

comparison of national occurrence 

studies (i.e., the true system 

contaminant means and national 

distributions of contaminant occurrence 

are not, and cannot, be known). The 

validation approach suggested by the 

commenter (i.e., basing the model on a 

portion of the data set and using the 

remainder to test the model) is intended 

for a regression-type of model using 

observed system means to develop a 

model for system-specific predictions. 

This approach is not possible for the 

six-year occurrence assessments, since, 

to the best of EPA’s knowledge, data on 

the true individual system contaminant 

mean concentrations and national 

distributions are not available. 

Regarding the other survey studies 

included in the Occurrence Summary 

Document, few, if any, provide the 

quantitative analytical results and 

national, representative coverage that 

would enable direct comparison to, or 

inclusion in, the Six-Year Review 

estimation analyses conducted with the 

16-State cross-section occurrence data. 

c. Other Issues Related to the 

Occurrence Technical Review. One 

commenter stated that the Agency’s 

current approach to estimate 

occurrence, employing a conservative 

methodology and making conservative 

simplifying assumptions in the absence 

of definitive data, was appropriate. On 

the other hand, the commenter argued 

that it was not appropriate for the 

Agency to conduct as massive a data 

collection and analysis project as was 

undertaken without clear quantitative 

objectives for the analysis identified a 

priori. The commenter noted that it was 

not apparent from either the April 17, 

2002, Federal Register or the 

Occurrence Methodology Document 

(USEPA, 2002e) that the Agency 

undertook an effort to set performance 

objectives for the occurrence estimation. 

The commenter felt that the 

Occurrence Methodology Document 

does not allow the reader to determine 

if the data are well apportioned among 

the categories for which results are 

reported. They also noted that they were 

unable to find indications in the support 

document that such an analysis was 

undertaken in preparation for 

constructing the Bayesian model. The 

commenter stated that the support 

document does not include actual 

numeric counts or ranges of detected 

values and suggested that it would be 

useful to have this information by 

contaminant, State, system size 

category, and water type, as well as an 

explicit count of non-detects by this 

same matrix. 

EPA Response: There are several 

general approaches when undertaking 

and designing studies that require large 

amounts of data. As the commenter 

states, a priori data quality objectives 

are part of one research approach where 

study objectives (including technical 

statistical performance measures) are 

set, determinations are made on how to 

meet those objectives, and then the 

study is designed and implemented 

accordingly. This ideal was not practical 

for the national occurrence study 

conducted for the Six-Year Review 

because EPA did not have the resources 

to generate original data, and was thus 

dependent on the data that could be 

obtained from the States. The approach 

taken by the Six-Year Review was to 

gather a large amount of data that, in 

aggregate, was expected to be indicative 

of national contaminant occurrence, 

develop an occurrence estimation model 

that built upon what has been learned 

from recent regulatory development 

work, and then evaluate how good the 

resulting model estimates are. 

As discussed in section IV.A.6.b of 

today’s action, the true national 

distributions of contaminant occurrence 

cannot be known. The 16-State national 

cross-section data set used for the SixYear Review is the largest compliance 

monitoring database for drinking water 

compiled by EPA to date. The database 

represents approximately 37 percent of 

the total number of public water 

systems and 43 percent of the total 

population served by public water 

systems in the United States. External 

peer reviews assessed the approach for 

developing the national cross-section 

and its ‘‘representativeness’’ separately 

under the Chemical Monitoring Reform 

(CMR) project (in 1998/1999) (USEPA, 

1999c) and the Six-Year Review project 

(USEPA, 2002e), and provided generally 

favorable comments. 

The data management and crosssection development have been 

described in detail in the support 

documents for the CMR and the SixYear Review. Further tabulations of the 

data have been generated and presented, 

as the commenter requested, in the final 

Occurrence Methodology Document 

(USEPA, 2003d). This information 

includes the numbers and percentages 

of analytical detections and nondetections for each contaminant in each 

of the system size and source water type 

categories. Generally, because of the 

large amount of data and the manner in 

which the Bayesian model handles data, 

the distribution of observations across 

the various categories does not 

significantly affect EPA’s estimates. The

42916 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

2These 15 chemical NPDWRs are: Benzene; 

beryllium; chlordane; 1,2-dibromo-3-

chloroproppane dichloromethane; 1,1-

dichloroethylene; 1,2-dichloropropane; heptachlor; 

heptachlor, epoxide; hexachlorobenzene; lindane; 

oxamyl; picloram; toxaphene; and 1,1,2-

trichloroethane.

3The other three NPDWRs in the data gaps 

category, chromium, fluorida, and lead, were placed 

there for reasons other than occurrence and 

economic considerations. Chrominum is in the data 

gaps category because of the studies being 

conducted by the National Toxicology Program 

studies. Fluoride is in the data gaps category 

pending a National Academy of Sciences update of 

the health risk assessment and review of the RSC 

assumptions. Lead is in the data gaps category 

based on consideration of public comments (see 

section IV.B.13 of today’s action).

number of analytical records differed by 

contaminant. EPA evaluated 27,648 to 

93,062 analytical records for the 

individual inorganic chemicals, 32,606 

to 121,327 records for the synthetic 

organic chemicals, and 123,229 to 

201,235 records for the volatile organic 

chemicals. Most importantly, the Stage 

2 occurrence model also quantifies the 

uncertainty of the estimates in the 

different categories of system size and 

source water type. Hence, the statistical 

significance of differences in occurrence 

between the categories can be easily 

assessed. However, the Agency believes 

it is more appropriate to consider the 

universe of potentially affected systems 

within the 16-State cross-section, rather 

than individual system categories, when 

making its revise/not revise decisions as 

part of the Six-Year Review process. 

7. Consideration of Available Economic 

Information 

Some commenters stated that, while 

the Agency’s review of NPDWRs was 

generally consistent with NDWAC 

recommendations to EPA (NDWAC, 

2000), it is not clear how the Agency 

took economic factors into account. 

EPA Response: An EPA 

memorandum, dated March 18, 2002, 

describes the Agency’s qualitative 

evaluation of economic factors (USEPA, 

2002c). This memorandum was cited in 

the April 17, 2002, Federal Register and 

is available in the docket for the SixYear Review (Docket No. OW–2002–

0012). It notes that detailed economic 

analyses were not deemed by the 

Agency to be necessary to support its 

decisions of whether or not to revise a 

particular NPDWR. Rather, a qualitative 

assessment, based on the extent of 

occurrence of a contaminant at the MCL, 

as well as at alternative levels, was 

undertaken to inform the Agency’s 

judgment about whether possible 

changes to an MCL offered a meaningful 

opportunity for health risk reduction 

and/or cost-savings to public water 

systems and their customers. EPA has 

conducted this assessment for 15 of the 

chemical NPDWRs for which the 

Agency had determined that a potential 

health or technological basis may exist 

for considering a revision to the MCLG/

MCL.2 EPA compared the estimated 

occurrence and exposure values at the 

current MCL and at potentially revised 

regulatory level(s). For 14 of these 

chemical NPDWRs, the Agency’s 

assessment showed that the differences 

were small. In EPA’s judgment, these 

differences are unlikely to provide a 

meaningful opportunity for health risk 

reduction or cost-savings to public 

water systems and their customers. 

After consideration of these factors, EPA 

decided that any revision would be a 

low priority activity for the Agency, 

and, thus, not appropriate to revise at 

this time because of: Competing 

workload priorities; the administrative 

costs associated with rule making; and 

the burden on States and the regulated 

community to implement any regulatory 

change that resulted. In the case of 

dichloromethane, the Agency did not 

have sufficient data to recalculate the 

PQL to support any potential regulatory 

revision and thus placed it in the data 

gaps category.3

B. What Comments or New Information 

Did EPA Receive on Chemical 

Contaminant-Specific Issues?

1. Alachlor 

One commenter stated that the Office 

of Pesticide Programs (OPP) found that 

the chloroacetanilide pesticides 

(acetochlor, alachlor, and butachlor) 

should be considered as a group of 

chemicals having a common mechanism 

of toxicity due to their ability to cause 

nasal turbinate tumors. The commenter 

believes EPA therefore should adopt a 

strong total chloroacetanilide pesticide 

standard that would strengthen the 

current standards. 

EPA Response: Butachlor and 

acetochlor do not presently have an 

NPDWR and thus, are not included in 

the Six-Year Review. However, 

acetochlor is included on the 

Contaminant Candidate List (CCL) and 

may in the future be considered as a 

candidate for regulation. Alachlor is a 

regulated drinking water contaminant 

and is included in the Six-Year Review. 

It is currently undergoing a risk 

assessment and, therefore, the Agency 

believes that revision of the NPDWR is 

not appropriate at this time. 

If the Agency decides to regulate 

either acetochlor or butachlor in the 

future, EPA may consider regulating 

them as a group, including alachlor, 

following a cumulative risk assessment 

process for pesticides that have a 

common mechanism of toxicity. It 

would be premature to propose a total 

chloroacetanilide pesticide standard 

until a cumulative risk assessment is 

completed because this analysis could 

impact the Agency’s evaluation of 

specific members of this group, or the 

group as a whole. 

2. Antimony 

a. Health Effects. A number of 

commenters have suggested that the 

current MCLG and MCL of 0.006 

milligrams per liter (mg/L) for antimony 

need to be revised. Some of the reasons 

given were: 

• The study used to derive the 

current MCLG (Schroeder et al.,1970) is 

not consistent with current good 

laboratory practice guidelines and there 

are several newer studies of antimony 

toxicity that should be considered in 

deriving a new reference dose (RfD). 

• Animals used in the Schroeder et 

al., 1970 study had a viral infection. To 

compensate for this infection, 

adjustments were made to the size of the 

animal groups in an attempt to salvage 

the data. 

• The antimony compound used in 

the Schroeder et al., 1970 study was 

potassium antimony tartrate, the most 

water soluble and toxic form of 

antimony. Antimony found in drinking 

water is likely to be in the form of less 

toxic trivalent and pentavalent 

antimony species. Therefore, basing the 

MCLG on the most toxic species of 

antimony (potassium antimony tartrate) 

is likely to overestimate the risk posed 

by antimony in drinking water. 

EPA Response: EPA agrees that the 

MCLG and MCL for antimony may need 

to be re-evaluated. EPA is in the process 

of developing a new health risk 

assessment for antimony, taking into 

consideration new studies that have 

become available on the toxicity of 

antimony. EPA expects to complete the 

health risk assessment for antimony in 

the 2003–2004 time frame (68 FR 5870, 

February 5, 2003 (USEPA, 2003h)). As a 

result of the ongoing health risk 

assessment, a revision to the antimony 

standard is not appropriate at this time, 

and antimony will be re-evaluated as 

part of the next Six-Year Review 

process. 

b. Treatment and Implementation 

Issues. Several commenters questioned 

the appropriateness of the antimony 

MCL, and the effectiveness of using the 

EPA-designated best available 

technologies (BATs) to meet the 

antimony MCL. A few small systems in 

Utah have levels of antimony in water 

at or above the MCL value of 0.006 mg/

L. These systems were granted

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42917

4The IRED is an intermediate decision for an 

individual pesticide that does not take into account 

cumulative risk issues for pesticides with a 

common mode of action. The RED does include 

cumulative risk. If an IRIS assessment is also in 

process when the IRED or RED is signed, EPA will 

make a case-by-case decision on whether to wait for 

the IRIS assessment before considering possible 

revisions to the NPDWR.

5Section 303(d) of the Clean Water Act and the 

implementing regulations (40 CFR 130.7) require 

States to develop TMDLs for waters where required 

point and nonpoint source pollution controls are 

not stringent enough to attain or maintain 

compliance with State water quality standards after 

the application of technology-based and other

Continued

exemptions contingent upon testing and 

installation of treatment by March 2004. 

These systems are investigating 

treatment options for the removal of 

antimony from their source water. 

Commenters submitted supporting data 

documenting the results of their testing 

and cost analyses. According to 

commenters, on-site testing indicated 

that the designated BATs (i.e., reverse 

osmosis and coagulation/filtration) and 

most of the other tested treatments were 

ineffective and/or prohibitively 

expensive due to: raw water quality 

concerns; water conservation needs; 

current costs for water production; and 

other concerns, such as waste water 

management. However, commenters did 

identify treatment options that may be 

feasible, but these may require further 

investigation prior to full scale use. 

EPA Response: As discussed in the 

April 17, 2002, Federal Register and as 

noted in the previous response in 

section IV.B.2.a, EPA does not believe it 

is appropriate to consider revisions to 

the NPDWR for antimony at this time 

because of the ongoing health risk 

assessment (67 FR 19030 at 19051 

(USEPA, 2002g)). 

When EPA initially promulgated the 

antimony NPDWR in 1992, the Agency 

estimated that 200 public water systems 

would be affected (USEPA, 1992). EPA 

recognizes that implementation of this 

standard may present challenges for a 

few localities. Although the use of the 

designated BATs for antimony may not 

be appropriate in some cases, as long as 

systems comply with the MCL, they are 

not limited to these technologies. 

EPA believes that the treatment data 

generated by the commenters may be 

valuable and may provide insight into 

potential alternative treatment 

technologies. The Agency has revised 

the document, ‘‘Water Treatment 

Technology Feasibility Support 

Document for Chemical Contaminants; 

In support of EPA Six-Year Review of 

National Primary Drinking Water 

Regulations’’ (Treatment Feasibility 

Document) (USEPA, 2003g) to refer to 

these preliminary test data as they may 

be applicable to the development of 

potential new treatment technologies for 

the removal of antimony and other 

contaminants. 

3. Atrazine 

a. Health Effects. Several commenters 

addressed the EPA decision not to 

consider revision of the MCL for 

atrazine at this time. Some of these 

commenters stated that EPA should use 

the risk assessment, released by OPP in 

May 2002, as a basis for reconsidering 

the atrazine NPDWR. One of the 

commenters noted that the 2002 risk 

assessment is based on reproductive and 

developmental endpoints which 

represents a change from the toxicity 

endpoint that formed the basis of the 

current MCLG. Two commenters stated 

that the MCL for atrazine should be 

revised upward because of the results of 

the 2002 OPP risk assessment in which 

the RfD increased and the cancer 

classification changed from ‘‘possible 

human carcinogen’’ to ‘‘not likely to be 

a human carcinogen.’’ The commenters 

stated that the change in the cancer 

assessment implies elimination of the 

additional 10-fold risk management 

factor used in 1991 to derive the MCLG/

MCL for atrazine. Another commenter 

stated that atrazine should be regulated 

using a non-linear approach which 

recognizes that there is a level at which 

no known health effects occur and that 

these findings must be part of the new 

MCL.

Conversely, another commenter stated 

that there is substantial new evidence 

from epidemiological and occupational 

studies that atrazine poses a serious 

cancer risk, and that it is an endocrine 

disruptor at low levels. The commenter 

believes EPA should adopt a revised 

atrazine and total triazine standard 

lower than (i.e., more stringent than) the 

current 0.003 mg/L standard for 

atrazine. 

A commenter also urged the Agency 

to: 

• Provide a definitive timetable for 

review of the standard; 

• Outline a preliminary scope for its 

review of the standard; and 

• State the underlying premise for the 

scope of the review. 

Other commenters stated that the 

existing NPDWR only regulates the 

parent compound atrazine, and that a 

revised NPDWR should include the 

chloro-metabolite degradants (i.e., 

diaminochlorotriazine (DACT), desethyl 

atrazine (DEA), and desisopropyl 

atrazine (DIA)). These commenters 

believe that inclusion of the chlorometabolites would strengthen 

compliance monitoring programs for 

public water systems under SDWA and 

thereby strengthen public health 

protection. They stated that a regulation 

for atrazine and the chloro-metabolites 

should be developed and promulgated 

within the next 12 to 18 months. 

Another commenter stated that since the 

Agency has found that atrazine, 

simazine, propazine, and the degradants 

DACT, DEA, and DIA have a common 

mechanism of toxicity, these should be 

regulated in a total triazine regulation. 

EPA Response: EPA does not believe 

it is appropriate to consider revisions to 

the NPDWR for atrazine at this time 

because the revised risk assessment has 

not been finalized. For purposes of the 

Six-Year Review protocol, EPA 

considers a risk assessment final when 

an Interim Reregistration Eligibility 

Decision (IRED), Reregistration 

Eligibility Decision (RED), and/or IRIS 

assessments are complete.4 Even though 

an IRED for atrazine was signed on 

January 31, 2003, an amended IRED is 

scheduled to be released in October 

2003 which will include a Scientific 

Advisory Panel (SAP) peer review of 

new data related to health effects. Based 

upon the outcome of the SAP review, 

the October 2003 IRED may include 

additional information that could 

impact a revise/not revise decision. 

Therefore, EPA does not believe it is 

appropriate to consider possible 

revisions to the NPDWR at this time.

In reviewing the atrazine regulation, 

EPA will apply an approach consistent 

with the protocol used for the current 

review. The Agency will consider the 

same key elements (i.e., health effects 

review, technology review, other 

regulatory revisions review, and, if 

appropriate, occurrence/exposure 

analyses and consideration of available 

economic information) and apply the 

same basic decision tree for making a 

revise/not revise decision. 

To address the issue of regulating the 

triazines as a group, the Agency is 

evaluating the unregulated triazines as 

part of the CCL process. When the risk 

assessment is completed for atrazine, 

the Agency will consider whether or not 

there are compelling reasons for 

considering a revision to the atrazine 

regulation or to wait until the risk 

assessment for the triazines, which 

considers issues of cumulative risk, is 

finalized. EPA will use the CCL 

regulatory determination process in 

deciding whether the triazines should 

be regulated as a group. 

b. Costs of Treatment. Commenters 

stated that the costs associated with not 

revising the MCL are great. These 

commenters are concerned that State 

agencies will be required to develop 

total maximum daily loads (TMDLs) 

based on 303(d) 5 listings resulting from

42918 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

required controls. A TMDL establishes the 

maximum amount of a pollutant that may be 

introduced into a waterbody while still ensuring 

attainment and maintenance of water quality 

standards.

6Since NTP is posting its progress on its internet 

site http://ntp-server.niehs.nih.gov/htdocs/Studies/

HexChromium/hexchromiumpg.html, EPA and the 

public will be able to evaluate the new data relative 

to the existing EPA assessment for chromium VI as 

it is released.

an outdated MCL which creates a 

burden on State and local government, 

its citizens, and diverts limited 

resources away from programs that 

provide real benefits. Some commenters 

also stated that the treatment costs to 

hundreds of community water systems 

are considerable. One commenter also 

stated that these are real dollars that 

would otherwise be available for 

emergency services, education, nutrition 

programs, and other vital programs that 

are the responsibilities of local and State 

agencies.

EPA Response: As stated in the 

previous response in section IV.B.3.a, 

EPA does not believe it is appropriate to 

revise the NPDWR for atrazine at this 

time because the risk assessment is not 

yet final. If EPA decides to revise the 

NPDWR for atrazine, economic factors, 

including feasibility and an assessment 

of costs and benefits, will be taken into 

consideration for the drinking water 

program. 

4. Beryllium 

Two commenters believed that the 

current drinking water standard for 

beryllium is more stringent than 

necessary for the protection of public 

health and felt that EPA should adopt a 

higher value for the beryllium standard. 

These commenters disagreed with EPA 

on the use of an uncertainty factor of 

300 in deriving the 1998 RfD. The 

commenters stated the use of 

uncertainty factors of 3 for database 

uncertainty, 10 for extrapolating data 

from a dog study to humans, and 10 for 

intraspecies variation is inappropriate. 

The commenters stated that EPA has the 

authority to raise the current drinking 

water standards for beryllium based on 

new information that allows for a 

smaller margin of safety than the one 

used by EPA. The commenter felt that 

the current standard for beryllium is 

‘‘lower than necessary to protect the 

public from beryllium toxicity and 

results in clean-up standards that are 

lower than naturally occurring level of 

beryllium in water sources and soils.’’

This commenter also expressed concern 

that the local application of the Federal 

drinking water standard to private wells 

in some cases caused undue concerns 

among users of those wells. 

EPA Response: One of the purposes of 

the Six-Year Review is to determine if 

the MCL of a chemical should be 

changed based on a revised RfD or 

cancer classification. Analytical 

methods and treatment technologies are 

considered, as well as occurrence in 

public water systems. The RfD for 

beryllium was revised in 1998 based on 

extensive Agency internal and external 

reviews, and is unlikely to be revised in 

the absence of new data. The 1998 

assessment also provided separate 

cancer classification for inhalation and 

oral exposures (USEPA, 1998). In the 

revised assessment, the carcinogenicity 

of beryllium by the inhalation route was 

described as ‘‘likely,’’ while that by the 

oral route of exposure ‘‘cannot be 

determined.’’ As discussed in the April 

17, 2002, Federal Register, the Agency 

considered the occurrence of beryllium 

at both potentially higher and lower 

regulatory levels. EPA concluded that a 

revision to the NPDWR would not result 

in a meaningful opportunity for health 

risk reduction or cost-savings to public 

water systems and their customers. As 

a result, revision of this NPDWR is a 

low priority action for the Agency and 

is not appropriate at this time.

The goal of drinking water standards 

is to protect public health. Therefore, it 

does not matter whether the source of 

contamination is naturally-occurring or 

man-made. While EPA appreciates the 

information on private wells, the SDWA 

requirements do not apply to private 

wells (i.e., wells that are not part of a 

‘‘public water system’’). The costs and 

benefits of a drinking water standard are 

assessed only with regard to the impacts 

on public water systems and their 

customers. 

5. Carbofuran 

Some commenters mentioned that the 

Agency concluded that N-methyl 

carbamates, including carbofuran, 

should be considered as a class because 

they have a common mechanism of 

toxicity. Therefore, they believe EPA 

should issue a stronger standard for 

total N-methyl carbamates, including 

carbofuran, which would be more 

stringent than the current carbofuran 

standard of 0.04 mg/L. 

EPA Response: EPA is re-evaluating 

the toxicity of carbofuran. However, a 

final assessment has not been issued by 

EPA. The Agency considers N-methyl 

carbamate pesticides as a group of 

chemicals having a common mechanism 

of toxicity due to their ability to inhibit 

acetylcholinesterase. However, it is not 

appropriate to revise the NPDWR for 

carbofuran at this time because the 

Agency has not yet completed the final 

health risk assessment for carbofuran or 

the other N-methyl carbamates. 

6. Chromium 

One commenter requested that EPA 

move quickly in making a revise/not 

revise determination once the new data 

on chromium become available from the 

National Toxicology Program (NTP) 

studies of the health effects of 

chromium VI. 

EPA Response: The NTP studies that 

the commenter refers to should be 

available before the end of the next SixYear Review cycle. Meanwhile, EPA is 

continuing to follow the progress of 

NTP in conducting subchronic and 

chronic studies of chromium VI.6 NTP 

made the data from the subchronic 

portion of the study available to the 

public in June 2002 (NTP, 2002). A peer 

review meeting was held at NTP on July 

24, 2002. EPA will examine the peer 

review report covering the subchronic 

data once it becomes available. Once the 

subchronic and chronic studies are 

completed, the health effects data will 

be evaluated with regard to their impact 

on the present RfD and cancer 

assessment, and integrated with the 

occurrence and analytical method data 

before making a new revise/not revise 

decision.

7. 1,1-Dichloroethylene 

In the April 17, 2002, Federal 

Register, the Agency preliminarily 

placed 1,1-dichloroethylene in the no 

revision category because a health risk 

assessment was pending at the time of 

publication. Since the publication of the 

April 17, 2002, Federal Register, the 

Agency has finalized the risk 

assessment for 1,1-dichloroethylene. 

The remaining paragraphs in this 

section include a brief background 

discussion about the original 

promulgation of the 1,1-

dichloroethylene NPDWR, the results of 

the appropriate six-year technical 

reviews and the Agency’s revise/not 

revise decision. 

a. Background. EPA published the 

current NPDWR for 1,1-

dichloroethylene on July 8, 1987 (52 FR 

25690 (USEPA, 1987)). The NPDWR 

established an MCLG and an MCL of 

0.007 mg/L. The Agency based the 

MCLG on an RfD of 0.009 milligram per 

kilogram of body weight per day (mg/

kg/day) and a cancer classification of C, 

possible human carcinogen. 

b. Technical Reviews. EPA updated 

the risk assessment for 1,1-

dichloroethylene on August 13, 2002 

(USEPA, 2002i). The new risk 

assessment established an RfD of 0.046 

mg/kg/day, based on the same 

toxicological study as that of the MCLG, 

but using an uncertainty factor of 100

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42919

instead of 1,000, and using benchmark 

dose modeling for the dose-response 

analysis. Under the 1986 cancer 

guidelines (51 FR 33992, September 24, 

1986 (USEPA, 1986)), 1,1-

dichloroethylene was assigned to Group 

C, possible human carcinogen. Under 

the draft revised ‘‘Guidelines for 

Carcinogen Risk Assessment’’ (USEPA, 

1999a), the data for 1,1-dichloroethylene 

were considered inadequate for an 

assessment of human carcinogenic 

potential by the oral route. 

Based on the change in RfD for 1,1-

dichloroethylene, using a 20 percent 

RSC and a 10-fold risk management 

factor for possible carcinogenicity, EPA 

used 0.03 mg/L as a level for evaluating 

the occurrence data. Without the use of 

the 10-fold risk management factor, EPA 

also used 0.3 mg/L as a level for 

evaluating the occurrence data. 

Analytical or treatment feasibility do 

not pose any limitations for the current 

MCL and would not be a limiting factor 

at the 0.03 mg/L or the 0.3 mg/L level 

(USEPA, 2002a; USEPA, 2003g). The 

Agency’s review of possible ‘‘other 

regulatory revisions’’ did not identify 

any issues that are specific to 1,1-

dichloroethylene (USEPA, 2003b). 

EPA evaluated the results of the 

occurrence and exposure analyses for 

1,1-dichloroethylene to determine 

whether possible changes to the 

standard would be likely to result in a 

meaningful opportunity for cost-savings 

to public water systems and their 

customers (USEPA, 2003d). Table IV–1 

shows the results of the detailed 

occurrence and exposure analysis based 

on the 16-State cross-section for the 

current MCL (0.007 mg/L), and for two 

higher levels (0.03 mg/L and 0.3 mg/L). 

Based on the detailed analysis, it 

appears that 1,1-dichloroethylene is 

unlikely to occur at concentrations 

above 0.007 mg/L in the States used for 

the cross-section. 

BILLING CODE 6560–50–P

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BILLING CODE 6560–50–C


EN18JY03.071</GPH>
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The results of the detailed occurrence 

and exposure analysis indicate that less 

than 0.02 percent of the 19,101 systems 

sampled in the 16-State cross-section, 

and less than 0.02 percent of the 

population served by those 19,101 

systems might be affected if EPA were 

to consider levels as high as 0.03 mg/L 

to 0.3 mg/L. The current BATs and 

small system compliance technology for 

1,1-dichloroethylene have other 

beneficial effects (e.g., reduction of 

other co-occurring contaminants, or 

other common impurities) in addition to 

1,1-dichloroethylene removal. 

Therefore, if EPA were to consider any 

of these higher levels, the Agency does 

not know how many of these public 

water systems that are currently treating 

to comply with the current MCL of 

0.007 mg/L would be likely to 

discontinue treatment that is already in 

place (USEPA, 2002c; USEPA, 2003g). c. Current Decision. Although there 

are new health effects data that might 

support calculation of a less stringent 

standard for 1,1-dichloroethylene, EPA 

does not believe a revision to the 

NPDWR for 1,1-dichloroethylene is 

appropriate at this time. In making this 

decision, the Agency considered 

whether any potential revision to the 

1,1-dichloroethylene NPDWR is likely 

to provide a meaningful opportunity for 

cost-savings to public water systems and 

their customers. After consideration of 

this factor, EPA has decided that any 

revision to 1,1-dichloroethylene would 

be a low priority activity for the Agency, 

and, thus, is not appropriate to revise at 

this time because of: • Competing workload priorities; • The administrative costs associated 

with rulemaking; and • The burden on States and the 

regulated community to implement any 

regulatory change that resulted. 

8. Dichloromethane 

One commenter stated that it may be 

difficult to lower the PQL for 

dichloromethane below the range of 

0.001 to 0.002 mg/L since it is required 

in a number of EPA methods and 

therefore is a common laboratory 

contaminant. Because it is a common 

laboratory contaminant, the commenter 

stated that using the MDL for 524.2 and 

502.2 does not constitute a reasonable 

basis for assuming that the PQL can be 

lower. The commenter stated that none 

of the existing WS studies had spike 

samples this low and, in addition, the 

occurrence data may have been 

compromised due to laboratory 

contamination. 

EPA Response: The basis for EPA 

indicating that a lower PQL ‘‘may exist’’

was due to the fact that laboratories had 

greater than 95 percent laboratory 

passing rates using a +/¥40 percent 

acceptance window at ‘‘known’’ spike 

concentrations close to current MCL of 

0.005 mg/L. If laboratory contamination 

due to dichloromethane were a problem, 

such high passing rates at this value 

would not be expected. The MDLs for 

524.2 and 502.2 were only used with the 

10 times MDL multiplier to estimate 

what the lower value could be. 

However, EPA does agree that, at this 

time, the Agency does not have 

sufficient data to recalculate the PQL for 

dichloromethane and for this reason, the 

Agency placed it in the data gap 

category. Regarding the occurrence issue, EPA 

has no data to suggest that high 

occurrence values were due to false 

positives from laboratory contamination 

and the Agency is proceeding on the 

assumption that State data are accurate 

unless there is information to the 

contrary. If laboratory contamination 

due to dichloromethane does exist, 

laboratories should be able to identify 

and discern a contamination issue if 

they are running laboratory blanks.

9. Di(2-ethylhexyl)adipate (DEHA) 

One commenter submitted detailed 

comments regarding di(2-

ethylhexyl)adipate (DEHA). The 

commenter believed that EPA should 

consider removing the regulation for 

DEHA and provided the following 

reasons: • The regulation of DEHA in drinking 

water does not provide any meaningful 

reduction in the health risk to humans 

because it is unlikely to cause adverse 

effects to humans, including 

reproductive effects, except at very high 

doses which cannot be attained in 

drinking water, due to the low water 

solubility of DEHA. • The weight of evidence indicates 

that the peroxisome proliferation 

mechanism of DEHA rodent 

carcinogenicity is not relevant to 

humans. Thus, the MCLG for DEHA 

should not include an additional 10-fold 

risk management factor for possible 

carcinogenicity. • The legislative history of the 1996 

SDWA indicates that Congress 

envisioned circumstances where 

relaxation of an MCL would provide the 

same level of health protection as the 

existing regulation. Accordingly, if 

DEHA cannot be deregulated, the 

commenter believes the MCLG and MCL 

should be increased. 

EPA Response: DEHA was regulated 

in 1992. Since that time, new studies 

have become available on the toxicity of 

DEHA and its metabolites. For this 

reason, EPA decided to initiate a new 

health risk assessment of DEHA (67 FR 

1212, January 9, 2002 (USEPA, 2002a)). 

The assessment will include 

examination of the studies on which the 

current NPDWR is based, as well as an 

evaluation of the data provided by this 

commenter and new studies that have 

become available since DEHA was 

regulated. This health risk assessment is 

planned for completion in the 2003–

2004 time frame (68 FR 5870, February 

5, 2003 (USEPA, 2003h)) and is 

expected to include development of an 

RfD for non-cancer health effects, as 

well as an assessment of potential 

carcinogenicity from oral exposure. At 

this time, it is premature to predict the 

outcome of the Agency’s assessment. 

Thus, as discussed in section IV.A.2.a of 

today’s action, the Agency believes that 

revision to the NPDWR for DEHA is not 

appropriate at this time. EPA will 

determine in the future if revision of the 

MCLG/MCL is warranted. Any revision 

to the MCLG/MCL will also take into 

consideration all the new information, 

including the water solubility of DEHA 

under various environmental 

conditions. 

As stated by the commenter, the 

legislative history of the 1996 SDWA 

Amendments supports EPA’s 

interpretation that the Agency could 

increase an MCLG and MCL as long as 

the relaxed standard does not lessen the 

level of public health protection. 

However, EPA does not believe, at the 

present time, that it can demonstrate 

that deregulating DEHA would maintain 

the current level of public health 

protection (see section IV.A.1.c of 

today’s action). 

10. Di(2-ethylhexyl)phthalate (DEHP) 

The same commenter who submitted 

comments on DEHA also submitted 

detailed comments regarding di(2-

ethylhexyl)phthalate (DEHP). The 

commenter felt that EPA should 

consider removing the regulation for 

DEHP for a variety of reasons, including 

the following: 

• The regulation of DEHP in drinking 

water does not provide any meaningful 

reduction in the health risk to humans. 

• The weight of the evidence 

indicates that the mode of action 

through which DEHP causes cancer in 

rodents is not relevant to humans and, 

thus, the MCLG for DEHP should not be 

zero. Any MCLG for DEHP should be 

based on a threshold endpoint and not 

on cancer. The commenter cited the 

February 2000 International Agency for 

Research on Cancer reclassification of 

DEHP from Group 2B (possibly 

carcinogenic to humans) to Group 3 (not 

classifiable as to its carcinogenicity to 

humans) as justification for 

recommending that EPA also reconsider 

its cancer classification.

42922 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

• The solubility of DEHP in drinking 

water is well below any concentrations 

that would pose a risk to humans. 

• If DEHP were to be considered for 

regulation under the statutory 

requirements of the 1996 SDWA, it 

would not be regulated. 

• The legislative history of the 1996 

SDWA indicates that Congress 

envisioned circumstances where 

relaxation of an MCL would provide the 

same level of health protection as the 

existing regulation. Accordingly, the 

commenter believes consideration 

should be given to increasing the MCLG 

for DEHP based on the new health 

effects data. 

• Reproductive effects from DEHP as 

observed in rodents do not appear to be 

relevant for primates and the doses that 

are associated with effects in animals 

are well above those that would be 

experienced for humans exposed 

through drinking water because of 

solubility limitations. The commenter 

also highlighted the findings of the NTP 

Center for the Evaluation of Risk to 

Human Reproduction that there was 

‘‘minimal concern for reproductive or 

developmental toxicity for the general 

population, based on estimates of total 

exposure to DEHP.’’

EPA Response: Revision of the 

NPDWR for DEHP is not appropriate at 

this time because an Agency health risk 

assessment is currently in process. The 

assessment is anticipated to be 

completed in the 2003–2004 time frame 

(68 FR 5870, February 5, 2003 (USEPA, 

2003h)). Advances in understanding 

differences between the primate and 

rodent response to DEHP and the body 

of toxicological data that have become 

available in the past decade motivated 

the Agency’s re-examination of DEHP 

and will be fully considered in the 

reassessment. 

Once the Agency assessment is 

completed, EPA will consider the 

findings and will determine if there is 

a compelling reason to review the DEHP 

NPDWR prior to the next Six-Year 

Review cycle. As discussed in sections 

IV.A.1.b and IV.A.2.a of today’s action, 

‘‘revise’’ versus ‘‘not revise’’ decisions 

under the Six-Year Review take into 

consideration occurrence, advances in 

analytical methods, treatment 

technologies, available economic 

information, and other factors. 

As stated by the commenter, the 

legislative history of the 1996 SDWA 

Amendments supports EPA’s 

interpretation that the Agency could 

increase an MCLG and MCL as long as 

the relaxed standard does not lessen the 

level of public health protection. 

However, EPA does not believe, at the 

present time, that it can demonstrate 

that deregulating DEHP would maintain 

the current level of public health 

protection (see section IV.A.1.c of 

today’s action). 

11. Fluoride 

EPA received three comments on the 

Agency’s decision to place fluoride in 

the data gap category while the National 

Academy of Sciences (NAS) examines 

the toxicological and RSC data 

published over the last decade. Two of 

the commenters supported EPA’s 

decision. One of these requested that the 

NAS concentrate its review on all of the 

data on the toxicology of fluoride and 

not just data on the critical skeletal 

effects. A third commenter requested 

that EPA not lower the MCL for fluoride 

from 4 mg/L to 2 mg/L and supported 

the 1986 EPA decision that dental 

fluorosis is a cosmetic effect rather than 

an adverse health effect. The commenter 

stated that the Public Health Service 

(PHS) recommended fluoridation level 

to be used at schools is 3 mg/L. The 

commenter also stated that if EPA were 

to lower the MCL, then schools that are 

currently fluoridating might have a 

conflict with the PHS recommendations 

and the EPA MCL. 

EPA Response: The National Research 

Council (NRC) of the NAS has agreed to 

review the toxicological data on fluoride 

that have been published since it 

completed the 1993 study of ‘‘Health 

Effects of Ingested Fluoride’’ (NRC, 

1993), and to examine the data on 

relative fluoride exposure from drinking 

water compared to fluoride exposure 

from the diet and fluoride-containing 

dental products. Although the Agency 

indicated in the April 17, 2002, Federal 

Register that new data on bone effects 

were a reason for initiating the data 

review (because bone effects were the 

basis of the present MCLG), the NAS 

review will look at the new 

toxicological data for all endpoints. It is 

anticipated that the NAS review will 

take about two years to complete. 

Because of this pending review, revision 

of the NPDWR for fluoride is not 

appropriate at this time. 

It is therefore premature to make any 

judgment regarding the NAS findings 

and whether or not they may lead to a 

consideration of a change in the MCL. 

However, PHS recommendations for 

school fluoridation programs are 

designed to provide the benefits of 

fluoridation without increasing the risk 

for dental fluorosis. The PHS 

recommends school water fluoridation 

only if: 

• The school has its own source of 

water;

• The school is not connected to a 

community water system; 

• More than 25 percent of students 

are not served by a public water system 

that provides water at levels adequate to 

protect against dental caries; and 

• The students served are 

kindergarten age or greater. 

12. Glyphosate 

Two commenters made the statement 

that, despite continued use of 

glyphosate in pesticide applications, 

available data and the Agency’s 

occurrence analysis, which includes a 

prediction of frequency of occurrence at 

levels below detection, indicate that 

glyphosate is not observed in 

compliance monitoring. One of these 

commenters stated that the occurrence 

appeared to be rare (less than 0.1 

percent) at concentrations 1,000 times 

lower than the MCL. In addition, 

according to the commenters, the cost of 

analyzing for glyphosate is expensive, 

since it is a single analyte analysis. 

Accordingly, the commenters wanted 

EPA to reconsider the glyphosate 

standard taking costs and benefits into 

account. The commenters felt that the 

data may indicate that a glyphosate 

standard is inappropriate and does not 

result in any additional public health 

protection. Therefore, the commenters 

recommended EPA pursue data gaps 

that the Agency would need to fill in 

order to demonstrate that eliminating 

the glyphosate standard would not 

lower public health protection. 

EPA Response: EPA is conducting an 

Agency risk assessment for glyphosate 

that will update the 1993 OPP 

assessment. As a part of this process, 

EPA is considering all the data that have 

been published or submitted to EPA 

since the completion of the RED in 1993 

(USEPA, 1993). Accordingly, revision of 

the glyphosate NPDWR is not 

appropriate at this time due to the 

pending Agency assessment. 

EPA recognizes that some utilities feel 

that the analysis of glyphosate in 

drinking water is expensive and that 

this should be taken into consideration 

with respect to cost and benefits. This 

will be considered when EPA evaluates 

glyphosate in the next review cycle 

(unless there is a compelling reason to 

evaluate glyphosate on an accelerated 

schedule). For the reasons stated in 

section IV.A.1.c of today’s action, EPA 

does not believe it is appropriate to 

consider deregulation of glyphosate at 

this time. 

13. Lead and Copper 

a. Research Needs. Three commenters 

acknowledged the Agency’s January 

2000 revisions to the Lead and Copper 

Rule (LCR) but stated that the Agency 

should continue to consider how to

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42923

make the LCR easier to implement. In 

particular, they recommended that the 

following three LCR-related research 

areas be incorporated into EPA’s overall 

research strategy: 

1. How well LCR monitoring results 

correlate to actual exposure and the 

effectiveness of the rule in protecting 

public health. 

2. Whether there is a correlation 

between water quality at indoor and 

outdoor taps. 

3. What effect the ban on lead in 

fixtures has had on lead levels and 

whether changes need to be made based 

on this ban. 

The commenters explained their 

rationale for recommending that the 

Agency determine if a correlation could 

be established between indoor and 

outdoor water quality. They stated that 

a major weakness of the LCR is that 

sample integrity may be compromised 

by allowing customers to collect water 

samples. If the Agency could establish 

such a correlation, the LCR could be 

revised to allow water system operators 

to collect samples from outdoor taps; 

thereby removing the need for customercollected sampling. 

EPA Response: EPA recognizes that 

the LCR is a challenging rule that 

requires difficult solutions to 

implement, but continues to believe that 

the public health objective addressed by 

the rule is as important and essential 

today as it was when the rule was first 

promulgated. Since the Agency 

promulgated the revisions to the LCR in 

January 2000 (65 FR 1950, January 12, 

2000 (USEPA, 2000)), the Agency has 

received no significant new information 

that would support a revision. However, 

the Agency recognizes that more 

research would be useful to obtain 

additional information that could be 

utilized to address some of the issues 

associated with the implementation of 

this rule. For this reason, EPA has 

revised its rationale for not revising the 

NPDWR for lead and placed it in the 

data gaps category. Although the 

Agency continues to believe that the 

NPDWR for copper belongs in the risk 

assessment in process category at the 

present time, EPA will also consider 

copper-related risk management and 

implementation issues as a part of any 

LCR-related research plans. The Agency 

is committed to working with 

stakeholders to support and coordinate 

identification and prioritization of LCRrelated research needs. Until this 

research is completed, EPA believes it is 

premature to consider revisions to the 

LCR; as a result, revision of the LCR is 

not appropriate at this time. 

The Agency believes that 

understanding the possible correlation 

between monitoring results and actual 

rates of exposure and public health 

protection is a valid issue. However, 

EPA recognized during the initial 

regulatory development of the LCR that 

a significant effort would be necessary 

to provide a statistically valid number 

and frequency of samples for an 

exposure assessment. The Agency thus 

adopted an alternative approach which 

specified a monitoring scheme that 

sought to ‘‘* * * assure that systems are 

performing ‘optimal corrosion control’

in part by requiring systems to conduct 

comprehensive tap sampling at homes 

specifically targeted for their potential 

to contain elevated levels of lead and 

copper’’ (56 FR 26460 at 26514, June 7, 

1991 (USEPA, 1991b)). One issue in 

assessing exposure reduction resulting 

from the LCR is a determination of an 

exposure baseline. EPA does not have a 

lot of data against which to measure 

changes in exposure that have occurred 

as a result of rule implementation. For 

these reasons, EPA believes that there is 

still insufficient information to change 

the basic monitoring approach adopted 

in the original rule, but recognizes that 

additional research may be useful. 

Research on whether a correlation 

exists between the water quality at 

indoor taps and water quality at outdoor 

taps is a very complex issue. Several 

variables potentially affect whether a 

reliable correlation exists between 

indoor and outdoor taps. These 

variables include: standing time within 

the system; contact time with the 

building plumbing; and the content of 

the interior plumbing. These variables, 

coupled with the fact that lead levels 

from building-to-building can be highly 

site-specific, make a correlation between 

indoor and outdoor taps difficult to 

establish. EPA continues to believe that 

focusing on the point of delivery to the 

customer most closely links the data 

collected to the water quality consumed 

by the customer. 

EPA recognizes the commenter’s 

concerns regarding the integrity of 

samples collected by drinking water 

customers. To date, however, the 

Agency has not been able to identify an 

acceptable alternative to monitoring at 

the consumer’s tap that can produce 

results equivalent to those obtained at 

the point of consumption in terms of 

ensuring adequate public health 

protection.

Regarding the commenter’s third 

recommendation, EPA will consider this 

research need as part of the Agency’s 

overall drinking water research 

planning process. 

b. Relaxing the Monitoring 

Requirements. Three commenters 

recommended that water systems be 

allowed to conduct water quality 

parameter (WQP) monitoring in lieu of 

continued lead and copper tap 

monitoring. One of these commenters 

added that this should be allowed once 

the system has demonstrated that it does 

not have a lead problem. This 

commenter also stated that the new 

requirements to use lead-free solder and 

plumbing fixtures should preclude 

problems with lead. Two commenters 

noted the difficulty that water systems 

are having maintaining their current 

sampling pool because homeowners no 

longer want to participate in the LCR 

monitoring program. One of these 

commenters recommended using WQP 

results to ensure corrosion control 

treatment is being adequately 

maintained and to stop lead and copper 

monitoring after three to five years. The 

commenter added that once the system 

ceases lead and copper monitoring, it 

can use public education to supplement 

continuing corrosion control, and can 

use coupons to demonstrate that 

corrosion rates meet accepted standards. 

EPA Response: While EPA is sensitive 

to the difficulties associated with the 

monitoring requirements of the LCR, the 

Agency is also concerned about the 

implications of reduced or discontinued 

monitoring. Significant treatment 

changes or water chemistry disturbances 

(such as new water sources, major pH/

coagulation changes, disinfectant 

changes, or seasonal water/treatment 

changes) can influence the effectiveness 

of corrosion control, which in turn will 

require appropriate adjustments of 

treatment. Current regulations require 

water systems to continue monitoring 

lead and copper levels to assure that 

water quality changes adversely 

affecting the presence of these 

contaminants in the drinking water are 

detected and to assure that appropriate 

adjustments to maintain optimal 

corrosion control are made. Proper 

process control, including water quality 

and corrosion inhibitor residual 

concentration monitoring in the 

distribution system, is the key to making 

any corrosion control or other treatment 

work, and assure the continuation of 

proper water quality. However, EPA 

recognizes that some changes might be 

justified in the future based on new, 

scientifically valid, information and/or 

research. EPA is considering aspects 

such as the implications of 

simultaneous treatment modifications 

on water quality, including lead and 

copper control, in its research planning. 

EPA is not yet able to determine 

whether the outcome of such research 

will provide a basis for modifications to 

the LCR treatment or monitoring

42924 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

7Treatment changes are categorized as changes to 

any water quality treatment process, including (but 

not restricted to) disenfection, disinfection byproduct removal, and corrosion control.

requirements. As stated in the response 

in section IV.B.13.a. of today’s action, 

EPA has placed the LCR in the data gaps 

category pending the completion of 

future research. 

c. Corrosion Control Treatment 

Strategy. Two commenters noted 

concerns regarding the lead and copper 

corrosion control strategy. One 

commenter indicated that the LCR 

should be revised to allow systems to 

change corrosion control strategies. The 

commenter stated that considerable 

development of the corrosion control 

market has occurred since systems made 

their initial assessments and 

implemented corrosion control 

programs. The commenter felt that 

currently, the ‘‘LCR locks utilities into 

a given control strategy,’’ when in some 

instances limited pilot work and 

ongoing WQP monitoring would allow a 

system to re-assesses its treatment and 

implement an alternative corrosion 

control inhibitor. 

The second commenter indicated that 

the current corrosion control strategies 

are marginally effective at preventing 

particulate lead and copper from 

entering the water supply. The 

commenter recommended that EPA 

consider methods for mitigating the 

release of insoluble components from 

plumbing fixtures. 

EPA Response: The Agency disagrees 

that the LCR locks utilities into a given 

control strategy, but feels it is necessary 

to demonstrate a sound basis for reassessing and implementing an 

alternative treatment strategy in the 

context of the existing regulation. EPA 

notes that the current regulation 

provides some flexibility to both States 

and water systems in the choice of a 

corrosion control strategy. For example, 

in response to its own initiative, a 

request by a water system or other 

interested party, a State may modify its 

determination of the optimal corrosion 

control treatment, among those listed in 

the Federal regulation, or may modify 

optimal WQPs if the State determines 

such changes are necessary to ensure 

that the system continues to optimize 

corrosion control treatment (40 CFR 

141.82(h)). 

The Agency believes that the existing 

requirements to notify the State when 

changing a corrosion control strategy 

remain necessary and appropriate. After 

they have optimized corrosion control, 

water systems must notify the State of 

any treatment changes 7 within 60 days 

of the change (40 CFR 141.90(a)(3)). The 

Agency encourages water systems to 

notify the State prior to making any 

changes thus allowing the Primacy 

Agency to review the changes to reduce 

the potential for detrimental sideeffects. In the Agency’s experience, 

changes in treatment, such as (but not 

restricted to) replacement of high pH 

treatment with corrosion inhibitor, 

changes in coagulant and coagulation 

conditions, changes in disinfection, 

installation of membrane processes, or 

introduction of chemically different 

waters into the distribution system 

provide potential for detrimental sideeffects. Water treatment changes, 

therefore, should only be done with the 

greatest care and pilot investigations. 

While changes to treatment can be made 

under the existing regulation, systems 

should conduct additional monitoring 

(e.g., of lead, copper, and WQPs) until 

the new treatment is fully implemented 

and stabilized.

EPA also recognizes that the current 

LCR may limit flexibility to some extent, 

particularly in the adoption of new or 

emerging technologies. The original rule 

attempted to balance this concern with 

the need to provide strong public health 

protection by ensuring that only control 

strategies of proven effectiveness are 

adopted. The Agency does not have an 

adequate basis to revise the treatment 

requirements at this time but will 

continue to monitor new developments, 

including emerging technology. The 

Agency may consider revisions to the 

LCR prior to the end of the next SixYear Review cycle if the Agency 

receives new, scientifically-valid, 

information that provides a basis for 

achieving significant improvement in 

public health protection or significant 

cost-savings to utilities and their 

customers while maintaining current 

public health protection. 

EPA has always recognized that the 

release of insoluble particulate material 

containing lead and copper can be an 

issue in some water systems. While 

more research may be of interest to 

improve optimization of corrosion 

control approaches with respect to this 

source, EPA expects that evaluations 

and pilot studies by water systems 

should include testing and 

consideration of the relative 

effectiveness of different treatments 

towards particulate release in systems 

for which it is important. 

d. Lead Levels in School Drinking 

Water. One commenter was concerned 

that the data on lead levels that was 

analyzed under the Six-Year Review of 

NPDWR standards may not indicate 

actual lead contamination of drinking 

water sources. As an example, the 

commenter noted that even though 

Baltimore City is in compliance for lead 

levels, 1⁄3 of Baltimore schools are using 

alternative sources of drinking water 

due to lead contamination. The 

commenter expressed concern that since 

data obtained from schools, such as the 

data from Baltimore, was not considered 

in the evaluation of lead contamination 

in drinking water, the most vulnerable 

population may not be protected from 

exposure to lead. The commenter stated 

that it is time for the Agency to reassess 

how lead levels are evaluated.

EPA Response: The LCR is designed 

to address system-wide problems with 

lead and copper contamination. The 

rule does not specifically target 

particular structures, such as schools, 

but rather contains a monitoring 

protocol designed to ensure that the 

overall levels of lead and copper 

system-wide are minimized. Once 

optimal treatment is implemented, any 

remaining problems with elevated lead 

levels in schools may be due to 

plumbing, coolers, or other materials in 

the building. These potential sources of 

lead in schools are of concern and for 

this reason are explicitly addressed 

under the provisions of the Lead 

Contamination Control Act of 1988 

(LCCA) (sections 1461 to 1465 of 

SDWA). The LCCA directed EPA to 

publish a guidance manual and testing 

protocol to assist States and schools in 

identifying sources and determining the 

extent of lead contamination in school 

drinking water and, if necessary, in 

remedying such contamination. In 

January 1989, the Agency published and 

distributed the guidance manual, ‘‘Lead 

in School’s Drinking Water,’’ to States 

and schools (USEPA, 1989). In 1994, the 

Agency updated and revised the 

guidance manual entitled ‘‘Lead in 

Drinking Water in Schools and Nonresidential Buildings’’ (USEPA, 1994). A 

copy of this manual may be obtained 

from the Safewater website http://

www.epa.gov/safewater/consumer/

leadinschools.html. In addition, the 

LCCA imposed a ban on the 

manufacture and sale of water coolers 

that are not lead free. The LCCA 

requirements are independent of the 

NPDWRs and therefore are not 

addressed under the Six-Year Review 

process. However, the Agency is 

continuing to work with schools and 

States to address problems dealing with 

lead in school drinking water. 

14. Lindane (g-hexachlorocyclohexane) 

In the April 17, 2002, Federal 

Register, the Agency preliminarily 

placed lindane in the no revision 

category because a health risk 

assessment was pending at the time of 

publication. One commenter stated that

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42925

the RED risk assessment for lindane, 

issued after publication of the April 17, 

2002, Federal Register, should be 

considered in the Agency’s review of 

the NPDWR and expressed concerns 

regarding the existing regulation. The 

commenter stated that the current 

NPDWR is based on an RfD developed 

in 1988 on the basis of adverse kidney 

effects and should be revised (USEPA, 

1988). The kidney effects were 

determined to occur through a pathway 

that is not relevant to human health risk 

assessment. The commenter stated that 

the new OPP toxicological assessment 

has resulted in a significant change to 

the quantitative dose-response 

assessment for lindane and that there 

are no data gaps or uncertainties which 

would prevent a revision of the NPDWR 

for lindane at this time. 

EPA Response: Since the publication 

of the April 17, 2002, Federal Register

and receipt of the comment regarding 

lindane, the Agency has finalized the 

risk assessment for lindane and signed 

the RED on July 31, 2002. The 

remaining paragraphs in this section 

include a brief background discussion 

about the original promulgation of the 

lindane NPDWR, the results of the 

appropriate six-year technical reviews 

and the Agency’s revise/not revise 

decision. 

a. Background. EPA published the 

current NPDWR for lindane on January 

30, 1991 (56 FR 3526 (USEPA, 1991a)). 

The NPDWR established an MCLG and 

an MCL of 0.0002 mg/L. The Agency 

based the MCLG on an RfD of 0.0003 

mg/kg/day and a cancer classification of 

C, possible human carcinogen. 

b. Technical Reviews. EPA updated 

the risk assessment on July 31, 2002 

(USEPA, 2002h). The new risk 

assessment established an RfD of 0.0047 

mg/kg/day. The Food Quality Protection 

Act (FQPA) of 1996 provides for an 

additional safety factor of up to 10-fold, 

if necessary, in assessing the risks to 

infants and children to take into account 

the potential for pre- and post-natal 

toxicity, and the completeness of the 

toxicity and exposure databases. This is 

referred to as the FQPA safety factor. 

The Agency concluded that an FQPA 

safety factor of three was required for 

lindane since there is evidence for 

increased susceptibility of the young 

demonstrated in a developmental 

neurotoxicity and two-generation 

reproductive toxicity study in rats. The 

rationale for using an FQPA safety factor 

of three is detailed in the RED. 

In accordance with the 1999 EPA 

Draft ‘‘Guidelines for Carcinogen Risk 

Assessment’’ (USEPA, 1999a), the 

Agency classified lindane as ‘‘suggestive 

evidence of carcinogenicity, but not 

sufficient to assess human carcinogenic 

potential.’’ Based on the RfD for lindane 

of 0.0047 mg/kg/day, the application of 

the additional FQPA safety factor of 

three to this RfD, a 20 percent RSC, and 

a 10-fold risk management factor of 

suggested evidence of carcinogenicity, 

EPA used 0.001 mg/L as a level for 

evaluating the occurrence data. 

Analytical or treatment feasibility do 

not pose any limitations for the current 

MCL and would not be a limiting factor 

at the 0.001 mg/L level (USEPA, 2003a; 

USEPA 2003g). The Agency’s review of 

possible ‘‘other regulatory revisions’’

did not identify any issues that are 

specific to lindane (USEPA, 2003b). 

EPA evaluated the results of the 

occurrence and exposure analyses for 

lindane to determine whether possible 

changes to the standard would be likely 

to result in a meaningful opportunity for 

cost-savings to public water systems and 

their customers (USEPA, 2003d). Table 

IV–2 shows the results of the detailed 

occurrence and exposure analysis based 

on the 16-State cross-section for 

concentrations of 0.0002 mg/L (the 

current MCL), and for 0.001 mg/L. 

Based on the detailed analysis, it 

appears that lindane is unlikely to occur 

at concentrations above 0.0002 mg/L in 

the States used for the cross-section. 

BILLING CODE 6560–50–P

42926 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

BILLING CODE 6560–50–C


EN18JY03.072</GPH>
Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42927

The results of the detailed occurrence 

and exposure analysis indicate that few, 

if any, of the 16,098 systems sampled in 

the 16-State cross-section might be 

affected if EPA were to consider levels 

as high as 0.001 mg/L. The current 

BATs and small system compliance 

technology for lindane have other 

beneficial effects (e.g., reduction of 

other co-occurring contaminants, or 

other common impurities) in addition to 

lindane removal. Therefore, if EPA were 

to consider a higher level, the Agency 

does not know how many of these 

public water systems that are currently 

treating to comply with the current MCL 

of 0.0002 mg/L would be likely to 

discontinue any treatment that is 

already in place (USEPA, 2002c; 

USEPA, 2003g). 

c. Current Decision. Although there 

are new health effects data that might 

support calculation of a less stringent 

standard for lindane, EPA does not 

believe a revision to the NPDWR for 

lindane is appropriate at this time. In 

making this decision, the Agency 

considered whether any potential 

revision to the lindane NPDWR is likely 

to provide a meaningful opportunity for 

cost-savings to public water systems and 

their customers. After consideration of 

this factor, EPA has decided that any 

revision to lindane would be a low 

priority activity for the Agency, and, 

thus, is not appropriate to revise at this 

time because of: 

• Competing workload priorities; 

• The administrative costs associated 

with rulemaking; and 

• The burden on States and the 

regulated community to implement any 

regulatory change that resulted. 

15. Simazine 

One commenter agreed that simazine 

should be addressed after the risk 

assessment is completed in 2003 or 

2004. The commenter requested that the 

Office of Water (OW) work closely with 

the OPP on the risk assessment at that 

time. The commenter also 

recommended that OW address the 

revision of the existing simazine 

NPDWR before the next review cycle 

year, scheduled for 2008. The 

commenter believes the extensive 

mammalian toxicology database, 

submitted as part of the Triazine Special 

Review, can be used in this process. 

EPA Response: OW has been 

coordinating with OPP for the revision 

of the atrazine and simazine risk 

assessments. Once the simazine risk 

assessment is completed, EPA will 

determine whether a compelling reason 

exists to consider review of the simazine 

NPDWR on an accelerated schedule. 

C. What Comments Did EPA Receive 

Regarding the Review of 

Implementation-Related Issues for 

Chemical NPDWRs? 

Several commenters recommended 

that EPA ensure consistent application 

of rules by making rules more consistent 

with respect to monitoring frequency, 

triggers for increased monitoring, 

criteria for returning to routine 

monitoring, and criteria for reducing 

sample requirements. In addition, 

commenters suggested that the Agency 

review possible ways for reducing the 

reporting burden on States, which could 

free up State resources currently used to 

implement rules. 

One commenter was concerned about 

monitoring and reporting issues in 

conjunction with CMR. The commenter 

felt that EPA should not miss an 

opportunity to relieve some of the 

unnecessary confusion that the 

monitoring requirements of Phase II and 

V have created. This confusion includes 

issues such as, what a detection is and 

what the monitoring requirements are 

for systems in States without a waiver 

program. EPA was encouraged to 

provide this consistency as much as 

possible, including using the standard 

monitoring framework to allow States 

and water systems to more easily 

understand rule requirements and 

reduce the need for States to update 

their data management systems. 

One commenter said EPA should 

ensure consistent application of rules by 

determining whether or not chronic 

contaminants should be regulated at 

non-transient non-community water 

systems (NTNCWSs), and review 

existing NPDWRs to ensure that rules 

are applied consistently. Another 

commenter recommended that the 

compliance language for the synthetic 

organic chemicals (SOCs) and volatile 

organic chemicals (VOCs) in the Final 

Arsenic Rule (66 FR 6975, January 22, 

2001 (USEPA, 2001)) be adopted for the 

inorganic chemicals (IOCs), and that 

systems not be considered in violation 

of the MCL until it has completed one 

year of quarterly samples. 

EPA Response: The Agency agrees 

that consistency across regulations is 

desirable to the extent that it does not 

jeopardize public health protection or 

the environment. 

As part of the Advanced Notice of 

Proposed Rulemaking for CMR (62 FR 

36100, July 3, 1997 (USEPA, 1997a)), 

EPA considered some of the issues 

raised by the commenters. However, 

during the comment period for the 

CMR, stakeholders generally indicated 

that the existing monitoring framework 

was sufficient. Most State commenters 

indicated that it would be too 

burdensome to adopt CMR. As a result, 

the Agency decided to take no further 

action on the CMR. However, the 

Agency established a standardized 

monitoring framework which applies to 

all of the regulated chemical and 

radiological contaminants (except lead 

and copper). The new chemical and 

radiological rules that EPA has 

promulgated (e.g., arsenic and 

radionuclides) are coordinated with the 

standardized monitoring framework. 

The Agency made special efforts to 

ensure that the reduced monitoring 

periods are in line with the 3-year 

compliance periods in the standardized 

monitoring framework. 

To assist States with understanding 

rule requirements, the Agency 

conducted a series of Phase II/V training 

in 2001. The training provided 

information to help States make 

informed decisions about reducing 

quarterly monitoring requirements. 

With respect to reduced monitoring, 

States currently have the flexibility to 

reduce the frequency of monitoring and/

or to waive sampling requirements for 

any given contaminant after minimum 

criteria are met to demonstrate that the 

system is reliably and consistently 

below the MCL and/or not vulnerable to 

contamination. 

NTNCWSs are traditionally regulated 

for chronic contaminants. However, 

through an alternative mechanism, the 

Agency is currently evaluating risk and 

exposure as they pertain to NTNCWS 

monitoring requirements. This review 

will not be completed in time for this 

Six-Year Review process. Until all the 

issues have been identified and specific 

options have been formulated, it will 

not be clear if a revision to regulations 

is indicated. 

EPA intends to consistently 

implement compliance determination 

provisions for IOCs, SOCs, and VOCs for 

all NTNCWSs and community water 

systems, as described in the preamble to 

the Final Arsenic Rule (66 FR 6975 at 

6990, January 22, 2001 (USEPA, 2001)). 

The rule makes compliance 

determinations based on a running 

annual average. The clarifications to 

compliance determinations for SOCs, 

IOCs, and VOCs are based on the 

average of the initial MCL exceedance 

and any subsequent State-required 

confirmation samples. States have the 

flexibility to require confirmation 

samples and more frequent monitoring, 

in addition to required quarterly 

samples. The average of the exceedance 

and confirmation sample constitutes the 

first quarterly sample. Compliance with 

the MCL is based on the average of the 

first quarterly sample and three

42928 Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 

additional samples over a period of one 

year, unless any one quarterly sample 

would cause the running annual average 

to exceed the MCL. Then the system is 

out of compliance immediately. 

D. What Comments Did EPA Receive on 

the Total Coliform Rule? 

Several commenters addressed the 

TCR. Several commenters raised several 

issues relating to monitoring. Some 

contended that routine monitoring 

should be focused on critical locations 

in the distribution system, rather than 

on the current requirement to monitor 

all parts of the distribution system. They 

also urged EPA to allow the use of 

dedicated sampling taps. Some 

commenters argued for allowing a 

finished water storage reservoir as a 

routine monitoring site. Two 

commenters urged EPA to focus on E. 

coli as the measure of water quality in 

the distribution system, rather than on 

total coliforms. In addition to routine 

monitoring, a few commenters 

addressed the topic of repeat samples 

after a total coliform-positive sample. 

One commenter, for example, urged 

EPA to eliminate the requirement to 

take upstream and downstream repeat 

samples after a total coliform-positive 

sample. Environmental groups urged 

EPA to strengthen the TCR and other 

rules that protect against pathogens, and 

exhorted EPA not to ease the TCR 

burden such that public health is 

compromised.

EPA Response: EPA’s announcement 

in the April 17, 2002, Federal Register

was only intended to discuss the 

Agency’s intent to begin the process for 

revising the TCR. EPA will consider the 

commenters’ suggestions as part of the 

revision process. As stated in the April 

17, 2002, Federal Register, the Agency 

plans to consider revisions to the TCR 

with new requirements for ensuring the 

integrity of distribution systems. The 

Agency remains committed to obtaining 

input from stakeholders as part of the 

rule development process. EPA agrees 

with the comment that public health 

should not be compromised, and will 

consider only those revisions that will 

assure public health protection. 

E. What Comments Did EPA Receive on 

Research Needs? 

Commenters found that EPA’s 

information on potential research 

resulting from the review of NPDWRs 

would be better represented by a 

summary of research needs that were 

identified by the Agency. Commenters 

felt that this summary is important to 

inform future regulatory decisions. 

Commenters also suggested additional 

research needs that had not been 

identified by EPA in its preliminary 

review. 

EPA Response: EPA agrees that the 

identification of research needs is an 

important component of the review of 

NPDWRs. Research findings may 

support future reviews and/or revisions 

to NPDWRs. 

The Agency is considering research 

needs that it identified as part of the 

review as well as those suggested by 

commenters. EPA will continue to 

identify areas where data are lacking. 

Dialogue with industry and other 

groups, including those that sponsor or 

conduct research on priority areas, 

would be beneficial to the drinking 

water program. Collaboration in 

sponsoring studies can provide multiple 

benefits. 

There are two research needs 

associated with the Six-Year Review 

that are being addressed through 

mechanisms external to EPA. The 

National Research Council of the 

National Academy of Sciences is 

conducting an assessment of recent data 

on fluoride health effects. In addition, 

the National Toxicology Program is 

conducting a study on chromium VI 

toxicity. Both of these research efforts 

are discussed in the April 17, 2002, 

Federal Register announcement of 

EPA’s preliminary revise/not revise 

decisions. The current review identified 

several general and specific areas of 

potential research related to treatment. 

The treatment-related research areas are 

briefly discussed in the Treatment 

Feasibility Document (USEPA, 2003g). 

EPA is currently in the process of 

examining whether specific research 

needs exist within each of the Six-Year 

Review areas of regulatory consideration 

(i.e., health effects, analytical methods, 

treatment, implementation, and 

occurrence/exposure). Some of the 

research needs identified during the 

Six-Year Review effort will be discussed 

in the context of the Multi-Year Plan 

(MYP) for drinking water. The MYP 

describes the EPA Office of Research 

and Development’s fiscal year 2003 to 

2010 research program to support the 

regulatory development activities of the 

EPA Office of Water. EPA plans to make 

this document available to the public in 

2003. 

V. References

National Drinking Water Advisory Council 

(NDWAC). 2000. Recommended 

Guidance for Review of Existing National 

Primary Drinking Water Regulations.

November 2000. Available on the 

Internet at:

http://www.epa.gov/safewater/ndwac/

guidfnl.pdf.

National Research Council (NRC). 1993. 

Health Effects of Ingested Fluoride. 

National Academy Press, Washington, 

DC. August 1993. Available on the 

Internet at: http://books.nap.edu/books/

030904975X/html/R1.html.

National Toxicology Program (NTP). 2002. 

NTP study of the hexavalent chromium 

compound sodium dichromate 

dihydrate. Available on the Internet at: 

http://ntp-server.niehs.nih.gov/htdocs/

Studies/HexChromium/

hexchromiumpg.html.

Schroeder, H.A., Mitchener, M. and Nason, 

A.P. 1970. Zirconium, niobium, 

antimony, vanadium and lead in rats: life 

term studies. Journal of Nutrition. 100: 

59–68. 

Senate Report. 1995. Committee of 

Environment and Public Works, Safe 

Drinking Water Act Amendments of 

1995, S. Doc. No. 169, 104th Cong., 1st 

Sess. 38 (1995). 

USEPA. 1986. EPA Guidelines for Carcinogen 

Risk Assessment. Federal Register. Vol. 

51, No. 185. p. 33992, September 24, 

1986. 

USEPA. 1987. National Primary Drinking 

Water Regulations—Synthetic Organic 

Chemicals; Monitoring for Unregulated 

Contaminants; Final Rule. Federal 

Register. Vol. 52, No. 130. p. 25690, July 

8, 1987. 

USEPA. 1988. Integrated Risk Information 

System, gamma-Hexachlorocyclohexane. 

Available on the Internet at: http://

www.epa.gov/iris/subst/0065.htm.

USEPA. 1989. Lead in School Drinking 

Water. EPA 570/9–89–001. January 1989. 

USEPA. 1991a. National Primary Drinking 

Water Regulations—Synthetic Organic 

Chemicals and Inorganic Chemicals; 

Monitoring for Unregulated 

Contaminants; National Primary 

Drinking Water Regulations 

Implementation; National Secondary 

Drinking Water Regulations; Final Rule. 

Federal Register. Vol. 56, No. 30. p. 

3526, January 30, 1991. 

USEPA. 1991b. Maximum Contaminant Level 

Goals and National Primary Drinking 

Water Regulations for Lead and Copper; 

Final Rule. Federal Register. Vol. 56, No. 

110. p. 26460, June 7, 1991. 

USEPA. 1992. Final Regulatory Impact 

Analysis National Primary Drinking 

Water Regulations: Phase V Synthetic 

Organic and Inorganic Chemicals. 

February 1992. 

USEPA. 1993. Reregistration Eligibility 

Decision (RED)—Glyphosate. EPA Report 

738–R–93–014. Washington, DC: Office 

of Prevention, Pesticides, and Toxic 

Substances. September 1993. Available 

on the Internet at: http://www.epa.gov/

oppsrrdl/REDs/old_reds/glyphosate.pdf.

USEPA. 1994. Lead in Drinking Water in 

Schools and Non-Residential Buildings. 

EPA 812–B–94–002. Office of Water. 

April 1994. 

USEPA. 1997a. National Primary Drinking 

Water Regulations—Advance Notice of 

Proposed Rulemaking. Federal Register.

Vol. 62, No. 156. p. 36100, July 3, 1997. 

USEPA. 1997b. Alternative Monitoring 

Guidelines. EPA 816–R–97–011. August 

1997. Available on the Internet at: http:/

Federal Register / Vol. 68, No. 138 / Friday, July 18, 2003 / Notices 42929

/www.epa.gov/safewater/regs/

pmrfin.html.

USEPA. 1998. IRIS, Beryllium and 

Compounds. Available on the Internet at: 

http://www.epa.gov/iris/subst/0012.htm.

USEPA. 1999a. Guidelines for Carcinogen 

Risk Assessment. NCEA–F–0644 Review 

Draft. Environmental Protection Agency 

Risk Assessment Forum. Washington, 

DC. July 1999. 

USEPA. 1999b. Revisions to the Unregulated 

Contaminant Monitoring Regulations for 

Public Water Systems; Final Rule. 

Federal Register. Vol. 64, No. 180. p. 

50556, September 17, 1999. 

USEPA. 1999c. A Review of Contaminant 

Occurrence in Public Water Systems. 

EPA 816–R–99–006. 78 pp. November 

1999. 

USEPA. 2000. National Primary Drinking 

Water Regulations for Lead and Copper; 

Final Rule. Federal Register. Vol. 65, No. 

8. p. 1950, January 12, 2000. 

USEPA. 2001. National Primary Drinking 

Water Regulation: Arsenic and 

Clarifications to Compliance and New 

Source Contaminants Monitoring; Final 

Rule. Federal Register. Vol. 66. No. 14. 

p. 6975, January 22, 2001. 

USEPA. 2002a. Integrated Risk Information 

System (IRIS); Announcement of 2002 

Program; Request for Information; 

Notice. Federal Register. Vol. 67, No. 6. 

p. 1212, January 9, 2002. 

USEPA. 2002b. Water Treatment Technology 

Feasibility Support Document for 

Chemical Contaminants; In support of 

EPA Six-Year Review of National 

Primary Drinking Water Regulations. 

EPA 815–D–02–001. Draft. February 

2002. 

USEPA. 2002c. An Evaluation of Available 

Economic Information in Support of the 

Six-Year Review of Existing National 

Primary Drinking Water Regulations. 

Memo from Marc Parrotta, Targeting and 

Analysis Branch, Office of Ground Water 

and Drinking Water. March 2002. 

USEPA. 2002d. EPA Protocol for Review of 

Existing National Primary Drinking 

Water Regulations. EPA 815–D–02–004. 

Draft. March 2002. 

USEPA. 2002e. Occurrence Estimation 

Methodology and Occurrence Findings 

Report for the Six-Year Review of 

Existing National Primary Drinking 

Water Regulations. EPA 815–D–02–005. 

Draft. March 2002. 

USEPA. 2002f. Occurrence Summary and 

Use Support Document for the Six-Year 

Review of Existing National Primary 

Drinking Water Regulations. EPA 815–

D–02–006. Draft. March 2002. 

USEPA. 2002g. National Primary Drinking 

Water Regulations—Announcement of 

the Results of EPA’s Review of Existing 

Drinking Water Standards and Request 

for Public Comment; Proposed Rule. 

Federal Register. Vol. 67, No. 74. p. 

19030, April 17, 2002. 

USEPA. 2002h. Reregistration Eligibility 

Decision (RED)—Lindane. EPA 738–R–

02–012. Office of Prevention, Pesticides, 

and Toxic Substances. July 2002. 

Available on the Internet at: http://

www.epa.gov/oppsrrdl/REDs/

lindane_red.pdf.

USEPA. 2002i. Integrated Risk Information 

System (IRIS), 1,1-Dichloroethylene. 

August 2002. Available on the Internet 

at:

http://www.epa.gov/iris/subst/0039.htm.

USEPA. 2003a. Analytical Feasibility 

Support Document for the Six-Year 

Review of Existing National Primary 

Drinking Water Regulations 

(Reassessment of Feasibility for 

Chemical Contaminants). EPA 815–R–

03–003. Final. March 2003. 

USEPA. 2003b. Consideration of Other 

Regulatory Revisions for Chemical 

Contaminants in Support of the Six-Year 

Review of National Primary Drinking 

Water Regulations. EPA 815–R–03–005. 

Final. June 2003. 

USEPA. 2003c. EPA Protocol for Review of 

Existing National Primary Drinking 

Water Regulations. EPA 815–R–03–002. 

Final. June 2003. 

USEPA. 2003d. Occurrence Estimation 

Methodology and Occurrence Findings 

Report for the Six-Year Review of 

Existing National Primary Drinking 

Water Regulations. EPA 815–R–03–006. 

Final. June 2003. 

USEPA. 2003e. Public Comment and 

Response Summary for the Six-Year 

Review of National Primary Drinking 

Water Regulations. EPA 815–R–03–001. 

Final. June 2003. 

USEPA. 2003f. Six-Year Review—Chemical 

Contaminants—Health Effects Technical 

Support Document. EPA 822–R–03–008. 

Final. June 2003. 

USEPA. 2003g. Water Treatment Technology 

Feasibility Support Document for 

Chemical Contaminants; In Support of 

EPA Six-Year Review of National 

Primary Drinking Water Regulations. 

EPA 815–R–03–004. Final. June 2003. 

USEPA. 2003h. Integrated Risk Information 

System (IRIS); Announcement of 2003 

Program; Request for Information and 

Announcement of Workshop; Notice. 

Federal Register. Vol. 68, No. 24. p. 

5870, February 5, 2003.

Dated: July 11, 2003. 

Linda J. Fisher, 

Acting Administrator.

[FR Doc. 03–18152 Filed 7–17–03; 8:45 am] 

BILLING CODE 6560–50–P