52194 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

ENVIRONMENTAL PROTECTION

AGENCY

[FRL–5904–7]

Announcement of the Draft Drinking

Water Contaminant Candidate List

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice.

SUMMARY: The Safe Drinking Water Act

(SDWA), as amended in 1996, requires

the Environmental Protection Agency

(EPA) to publish a list of contaminants

which, at the time of publication, are

not subject to any proposed or

promulgated national primary drinking

water regulation (NPDWR), that are

known or anticipated to occur in public

water systems and which may require

regulations under the SDWA [section

1412(b)(1)]. The SDWA, as amended,

specifies EPA must publish the first list

of contaminants (Drinking Water

Contaminant Candidate List, or CCL)

not later than 18 months after the date

of enactment, i.e., by February 1998,

and every five years thereafter. The

SDWA, as amended, also specifies that

the CCL must be published after

consultation with the scientific

community, and after notice and

opportunity for public comment.

Today’s notice announces the draft CCL,

provides background on how it was

developed, and seeks comment on

various aspects of developing the final

CCL. The CCL will be the source of

priority contaminants for drinking water

research, monitoring, guidance

development, and for selection of

candidates for drinking water

regulation. The draft CCL includes 58

chemical and 13 microbiological

contaminants.

DATES: Submit comments on or before

December 5, 1997.

ADDRESSES: Send written comments to

the Comment Clerk, docket number W–

97–11, Water Docket (MC4101), USEPA,

401 M. St., SW, Washington, DC 20460.

Please submit an original and three

copies of your comments and enclosures

(including references). Comments must

be received or postmarked by midnight

December 5, 1997.

Commenters who want EPA to

acknowledge receipt of their comments

should enclose a self-addressed,

stamped envelope. No facsimiles (faxes)

will be accepted. Comments may also be

submitted electronically to owdocket@epamail.epa.gov. Electronic

comments must be submitted as an

ASCII file avoiding the use of special

characters and any form of encryption.

Electronic comments must be identified

by the docket number W–97–11.

Comments and data will also be

accepted on disks in WordPerfect in 5.1

format or ASCII file format. Electronic

comments on this notice may be filed

online at many Federal Depository

Libraries.

The full record for this notice has

been established under docket number

W–97–11, and includes supporting

documentation as well as printed, paper

versions of electronic comments. The

full record is available for inspection

from 9 to 4 p.m. Monday through

Friday, excluding legal holidays at the

Water Docket, Room M2616,

Headquarters, USEPA, 401 M. Street,

SW, Washington, DC. For access to

docket materials, please call 202/260–

3027 to schedule an appointment.

Additionally, a few critical pieces of the

record have been made available at each

Regional Office.

FOR FURTHER INFORMATION CONTACT: For

general information, please contact the

EPA Safe Drinking Water Hotline. The

toll-free number is 800–426–4791. For

specific information on the CCL and the

contaminant identification process,

please contact Ms. Evelyn Washington,

at the U.S. Environmental Protection

Agency, Office of Ground Water and

Drinking Water, Mailcode 4607,

Washington, DC 20460, phone: 202–

260–3029, fax: 202–260–3762, email:

washington.evelyn@epamail.epa.gov.

EPA Regional Offices

I. JFK Federal Bldg., Room 2203, Boston, MA

02203. Phone: 617–565–3602, Jerry

Healey

II. 290 Broadway, Room 2432, New York, NY

10007–1866. Phone: 212–637–3880,

Walter Andrews

III. 841 Chestnut Street, Philadelphia, PA

19107. Phone: 215–566–5775, Jeff Hass

IV. 345 Courtland Street, NE, Atlanta GA

30365. Phone: 404–562–9480, Janine

Morris

V. 77 West Jackson Blvd., Chicago, IL 60604–

3507. Phone: 312–886–4239, Kim Harris

VI. 1445 Ross Avenue, Dallas, TX 75202.

Phone: 214–665–7150, Larry Wright

VII. 726 Minnesota Ave., Kansas City, KS

66101. Phone: 913–551–7410, Stan

Calow

VIII. One Denver Place, 999 18th Street, suite

500, Denver, CO 80202. Phone: 303–312–

6627, Rod Glebe

IX. 75 Hawthorne Street, San Francisco, CA

94105. Phone: 415–744–1884, Bruce

Macler

X. 1200 Sixth Avenue, Seattle, WA 98101.

Phone: 206–553–1893, Larry Worley

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background

II. Draft Drinking Water Contaminant

Candidate List

Table 1. Draft Drinking Water Contaminant

Candidate List

III. Identification of Contaminants for the

Draft Drinking Water Contaminant

Candidate List

A. Role of NDWAC Working Group

B. Microbiological Contaminants Identified

for the Draft CCL

Table 2. Initial List of Microorganisms

Developed by EPA for Consideration by

the Workshop on Microbiology and

Public Health

1. Protozoa

2. Viruses

3. Bacteria

4. Microbiological Indicators

5. Future Activities Planned for

Microbiological Contaminants and the

CCL

6. Possible Impacts From Other Regulatory

Activity

C. Chemical Contaminants Identified for

the Draft CCL

1. The Initial List of Chemical

Contaminants Considered

Table 3. Initial List of Chemical

Contaminants Considered during

Development of the Draft CCL

a. 1991 Drinking Water Priority List

b. Health Advisories

c. Integrated Risk Information System

d. Non-Target Analytes in Public Water

Supply Samples

e. CERCLA Priority List

f. Stakeholder Responses

g. Toxic Release Inventory

h. Pesticides Identified by Office of

Pesticide Programs

Table 4. Pesticides Deferred

i. Safe Drinking Water Hotline

Table 5. Contaminants Identified by the

Safe Drinking Water Hotline

j. Endocrine Disruptors

Table 6. Contaminants Identified as

Suspected of Endocrine Disruption

2. Development and Application of the

Criteria

a. Criteria for Occurrence

b. Criteria for Health

3. Additional Specific Contaminants

Included

a. Aldicarb, Aldicarb sulfoxide, and

Aldicarb sulfone

b. Nickel

c. Sulfate

IV. Contaminants on the CCL Which Are of

Specific Interest

A. Aluminum

B. MTBE

C. Organotins

D. Rhodamine WT

E. Sodium

F. Zinc

G. 2,6-di-tert-butyl-p-benzoquinone (DTBB)

H. Contaminants to be Considered as

Groups

I. Contaminants for Which Unregulated

Contaminant Data are or Will Be

Available

Table 7. Contaminants with Unregulated

Contaminant Monitoring Data

V. Request for Comment

A. Data and Research Needs

Table 8. Data Needs for Chemical

Contaminants Included on the Draft CCL

B. Perchlorate
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52195

1With the exception of nickel, aldicarb and its

degradates, and sulfate, which are considered

special cases. Refer to later sections of this notice

for rationale for inclusion.

VI. Development of the final Drinking Water

Contaminant Candidate List, the

Contaminant Identification Method, and

the Contaminant Selection Process

VII. Summary of Other Related Activity

Required by the SDWA

A. Contaminant Selection and Regulatory

Determination

B. The National Contaminant Occurrence

Database

C. Unregulated Contaminant Monitoring

Regulation

VIII. Summary of Concurrent Regulatory

Activity Required by the SDWA

A. Radon

B. Other Radionuclides

C. Arsenic

D. Sulfate

E. Disinfectants and Disinfection

Byproducts

IX. Other Requirements

X. References

Abbreviations Used in this Notice

ACWA-Association of California

Water Agencies

ATSDR—Agency of Toxic Substances and

Disease Registry

AWWARF—American Water Works

Association Research Foundation

CASRN—Chemical Abstract Services

Registry Number

CCL—Contaminant Candidate List

CDC-Center for Disease Control and

Prevention

CERCLA—Comprehensive Environmental

Response, Comprehensive and Liability

Act

CIM—Contaminant Identification Method

D/DBP—Disinfectants and Disinfection

Byproducts

DWEL-Drinking Water Equivalent Level

DWPL—Drinking Water Priority List

EDSTAC—Endocrine Disruptor Screening

and Testing Advisory Committee

EPA—Environmental Protection Agency

ESWTR—Enhanced Surface Water Treatment

Rule

FIFRA—Federal Insecticide, Fungicide, and

Rodenticide Act

FQPA—Food Quality Protection Act

GW—Ground Water

HA—Health Advisory

HSDB—Hazardous Substances Data Base

IARC—International Agency for Research on

Cancer

ICR—Information Collection Request

IESWTR—Interim Enhanced Surface Water

Treatment Rule

IRIS—Integrated Risk Information System

LTESWTR—Long-term Enhanced Surface

Water Treatment Rule

MCL—Maximum Contaminant Level

MCLG—Maximum Contaminant Level Goal

NAS—National Academy of Sciences

NCOD—National Contaminant Occurrence

Database

NDWAC—National Drinking Water Advisory

Council

NIPDWR—National Interim Primary Drinking

Water Regulations

NPDWR—National Primary Drinking Water

Regulations

NPL—National Priority List

NRC—National Research Council

OGWDW—EPA’s Office of Ground Water and

Drinking Water

OPP—EPA’s Office of Pesticide Programs

OPPTS—EPA’s Office of Pollution

Prevention and Toxic Substances

PWS—Public Water Systems

RDA—Recommended Daily Allowance

RfD—Reference Dose

RQ—Reportable Quantity

SAB—EPA’s Science Advisory Board

SDWA—Safe Drinking Water Act

STORET—Storage and Retrieval Database

SWTR—Surface Water Treatment Rule

TRI—Toxic Release Inventory

WHO—World Health Organization

I. Background

The Safe Drinking Water Act (SDWA),

as amended in 1996, requires the

Environmental Protection Agency (EPA)

to publish a list of contaminants that are

known or anticipated to occur in public

water systems, and which may require

regulations under the SDWA (section

1412(b)(1)). The SDWA, as amended,

specifies that EPA must publish this

first list of contaminants (Drinking

Water Contaminant Candidate List, or

CCL) not later than 18 months after the

date of enactment (i.e., by February

1998), and publish a CCL every five

years thereafter. The SDWA also

requires that the list of contaminants

include those which, at the time of

publication, are not subject to any

proposed or promulgated national

primary drinking water regulation

(NPDWR). The list must be published

after consultation with the scientific

community, including the Science

Advisory Board, after notice and

opportunity for public comment, and

after consideration of the occurrence

database established under section

1445(g). The unregulated contaminants

considered for the list must include, but

not be limited to, substances referred to

in section 101(14) of the Comprehensive

Environmental Response,

Compensation, and Liability Act of 1980

(CERCLA), and substances registered

under the Federal Insecticide,

Fungicide, and Rodenticide Act

(FIFRA).

Prior to the 1996 Amendments, the

SDWA required the EPA to publish a

drinking water priority list (DWPL) of

contaminants every three years which

were known or anticipated to occur in

drinking water and which may have

required regulation under the SDWA. In

response to these previous amendments,

EPA published two DWPLs which

served as candidates for regulation. The

first DWPL was published on January

22, 1988 (53 FR 1892), and the second

was published on January 14, 1991 (56

FR 1470).

The 1996 Amendments to the SDWA

were developed and enacted during the

time of the Presidential initiative

intended to substantially improve the

existing regulatory system to move the

Nation toward a new and better

environmental management system for

the 21st century. During the two-year

period prior to the 1996 Amendments,

EPA developed a National Drinking

Water Program Redirection Strategy

(EPA, 1996a) to (1) establish priorities

for setting safety standards based on

health risks and sound science; (2)

support strong, flexible partnerships

among EPA, States, local governments

and other stakeholders to protect public

health; and (3) promote effective

community-based source water

protection. The Redirection Strategy

provides an overall framework for the

development of the CCL, as well as for

other drinking water program activities.

The Agency believes the draft CCL

presented in today’s notice is the result

of a commendable effort of screening a

larger set of contaminants to the subset

of those of most concern. The draft CCL

is a first step toward improving risk

assessment, strengthening science and

data, and achieving better decisionmaking and future priority setting.

Today’s notice announces the draft CCL,

provides background on how it was

developed, summarizes detailed

material available in the docket and

used to develop the list, seeks comment

on the methods used to develop the

draft CCL, and seeks comment on

developing the final CCL. The draft CCL

is designed to be responsive to each of

the requirements noted above of the

SDWA, as amended, and is consistent

with the goals of the redirection

strategy.

Today’s notice is being published

pursuant to the requirement in section

1412(b)(1) that the CCL be subjected to

prior notice and opportunity for public

comment. The contaminants included

are not subject to any proposed or

promulgated national primary drinking

water regulation,1 are known or

anticipated to occur in public water

systems, and may require regulations

under the SDWA. During the

development of the draft CCL, the

Agency consulted with stakeholders,

including the National Drinking Water

Advisory Council’s Working Group on

Occurrence & Contaminant Selection,

which includes microbiologists,

toxicologists, public health scientists,

and engineers, and with other members

of the scientific community including

the Science Advisory Board (SAB). The

Agency plans for a more in-depth

consultation with the SAB during the
52196 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

fall of 1997. The occurrence database,

which is to be established under section

1445(g) by August 1999, was not

considered since it is currently under

development; however, occurrence data

from other sources was considered.

The final CCL, after publication in

February 1998, will be the source of

priority contaminants for the Agency’s

drinking water program. Priorities for

drinking water research, occurrence

monitoring, guidance development,

including the development of health

advisories, will be drawn from the CCL.

The CCL will also serve as the list of

contaminants from which the Agency

will make determinations of whether or

not to regulate specific contaminants.

This first CCL is largely based on

knowledge acquired over the last few

years and other readily available

information, but an enhanced, more

robust approach to data collection and

evaluation will be developed for future

CCLs.

II. Draft Drinking Water Contaminant

Candidate List

The following table includes the

contaminants, microbiological and

chemical, presented as the draft

Drinking Water Contaminant Candidate

List. The contaminants were identified

as described by Section III of today’s

notice. The contaminants in the table

are identified by name and Chemical

Abstracts Service Registry Number

(CASRN). The draft CCL includes 58

chemical contaminants/contaminant

groups and 13 microbiological

contaminants.

TABLE 1.—DRAFT DRINKING WATER

CONTAMINANT CANDIDATE LIST

Chemical contaminants CASRN

1,1,2,2-tetra-chloroethane ......... 79–34–5

1,2,4-trimethylbenzene ............. 95–63–6

1,1-dichloro-ethane ................... 75–34–3

1,1-dichloro-propene ................. 563–58–6

1,2-diphenylhydrazine ............... 122–66–7

1,3-dichloropropane .................. 142–28–9

TABLE 1.—DRAFT DRINKING WATER

CONTAMINANT CANDIDATE LIST—

Continued

Chemical contaminants CASRN

1,3-Dichloropropene (telone or

1,3-D) .................................... 542–75–6

2,4,6-trichlorophenol ................. 88–06–2

2,2-dichloro-propane ................. 594–20–7

2,4-dichlorophenol .................... 120–83–2

2,4-dinitrophenol ....................... 51–28–5

2,4-dinitrotoluene ...................... 121–14–2

2,6-dinitrotoluene ...................... 606–20–2

2,6-di-tert-butyl-p-benzoquinone

(DTBB) .................................. 719–22–2

2-methyl-Phenol (o-cresol) ....... 95–48–7

Acetochlor ................................. 34256–82–1

Acetone ..................................... 67–64–1

Alachlor ESA (a degradation

product of alachlor)

Aldicarbs*

Aldrin ......................................... 309–00–2

Aluminum .................................. 7429–90–5

Atrazine-desethyl, a degradation product of triazines ......... 6190–65–4

Boron ........................................ 7440–42–8

Bromobenzene .......................... 108–86–1

Cyanazine ................................. 21725–46–2

p-Cymene (p-isopropyltoluene) 99–87–6

DCPA mono-acid degradate ..... 887–54–7

DCPA di-acid degradate ........... 2136–79–0

DDE .......................................... 72–55–9

Diazinon .................................... 333–41–5

Dieldrin ...................................... 60–57–1

Dimethoate ................................ 60–51–5

Disulfoton .................................. 298–04–4

Diuron ....................................... 330–54–1

EPTC (s-ethyldipropylthiocarbamate) .......... 759–94–4

Fonofos ..................................... 944–22–9

Hexachloro-butadiene ............... 87–68–3

Isopropylbenzene (cumene) ..... 98–82–8

Linuron ...................................... 330–55–2

Manganese ............................... 7439–96–5

Methyl bromide ......................... 74–83–9

Methyl-t-butyl ether (MTBE) ..... 1634–04–4

Metolachlor ............................... 51218–45–2

Metribuzin ................................. 21087–64–9

Molinate .................................... 2212–67–1

Naphthalene .............................. 91–20–3

Nickel*

Nitrobenzene ............................. 98–95–3

Organotins

Prometon .................................. 1610–18–0

RDX .......................................... 121–82–4

TABLE 1.—DRAFT DRINKING WATER

CONTAMINANT CANDIDATE LIST—

Continued

Chemical contaminants CASRN

Rhodamine WT

Sodium ...................................... 7440–23–5

Sulfate*

Terbacil ..................................... 5902–51–2

Terbufos .................................... 13071–79–9

Vanadium .................................. 7440–62–2

Zinc ........................................... 7440–66–6

Microbiological Contaminants:

Acanthamoeba (guidance expected for

contact lens wearers)

Adenoviruses

Aeromonas hydrophila

Caliciviruses

Coxsackieviruses

Cyclospora cayetanensis

Echoviruses

Helicobacter pylori

Hepatitis A virus

Legionella (in ground water)

Microsporidia (Enterocytozoon & Septata)

Mycobacterium avium intracellulare (MAC)

Toxoplasma gondii

*Included on the CCL as special cases, not

subject to the criteria used to identify other

contaminants.

III. Identification of Contaminants for

the Draft Drinking Water Contaminant

Candidate List

Drinking water contamination

generally occurs from: (1) Contaminants

that find their way into drinking water

sources from industrial waste releases,

agricultural runoff, atmospheric

deposition, and other pollution sources;

(2) contaminants formed during the

treatment of water supplies (e.g.,

disinfection by-products); and (3)

materials used for treatment, storage,

and distribution of water. EPA has

considered all of these sources in

identifying microbiological and

chemical contaminants for this draft

CCL. Figure 1 provides a graphical

representation of how today’s draft CCL

was developed.

BILLING CODE 6560–50–P
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BILLING CODE 6560–50–C
52198 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

The National Drinking Water

Advisory Council’s (NDWAC) Working

Group on Occurrence & Contaminant

Selection played an integral part in the

development of the CCL by providing

recommendations for the criteria, and

the contaminants for initial

consideration. Also, during the

development of the CCL, the Agency

sought the expertise of microbiologists

for input on microorganisms to include

on the CCL. The following sections

describe the role of the NDWAC

Working Group and describe the

approach used to develop the CCL for

microorganisms and chemical

contaminants.

A. Role of NDWAC Working Group

After enactment of the recent SDWA

amendments, and in keeping with the

redirection strategy, EPA held its first

stakeholder meeting on approaches to

developing CCLs on December 2 and 3,

1996 in Washington, D.C. Participants,

including public water system

professionals, state regulatory officials,

public health officials, environmental

groups and other stakeholders, with a

range of interests, explored issues

concerning the identification of

potential drinking water contaminants

for consideration for the first CCL as

well as the factors to consider for future

CCL development. One result of the

meeting was the recommendation that

the February 1998 CCL be the first topic

addressed by the NDWAC Working

Group on Occurrence & Contaminant

Selection.

In 1975, pursuant to the SDWA

[Section 1446(a)], NDWAC was

established under the Federal Advisory

Committee Act to provide practical and

independent advice, consultation, and

recommendations to EPA on the

activities, functions and policies related

to the SDWA. At its meeting held on

November 13 and 14, 1996, NDWAC

decided that working groups should be

formed on the following subjects: Small

Systems Capacity Building; Operator

Certification; Source Water Protection;

Consumer Confidence Reports; Drinking

Water State Revolving Fund; and

Occurrence & Contaminant Selection.

The NDWAC Occurrence &

Contaminant Selection Working Group

has been integral to developing the

criteria and identifying contaminants for

the draft CCL published today.

At the recommendation of the

Working Group, the Agency sought

expertise on microbiological

contaminants and convened a workshop

of microbiologists. The input from the

workshop was adopted by the Working

Group for use in developing the draft

CCL. The approach used to identify

microorganisms for the CCL is

explained in more detail in section III.B.

In addition to microorganisms, the

Working Group developed

recommendations on chemical

contaminants. The recommendations

addressed which contaminants to

include for initial consideration, and the

criteria for use in determining which

contaminants should be included on the

draft CCL. The recommendations were

developed over a series of meetings with

the Working Group followed by the

endorsement by the full NDWAC. The

details concerning the contaminants

included for initial consideration, and

development and use the identification

criteria are contained in section III.C.

B. Microbiological Contaminants

Identified for the Draft CCL

On May 20–21, 1997, EPA utilized a

workshop on microbiology and public

health to develop a list of pathogens for

possible inclusion on the first CCL.

Taking part in this workshop were

invited experts representing academia,

EPA and other federal agencies, and the

water industry. In preparation, EPA

scientists prepared and distributed a list

of microorganisms for initial

consideration by workshop members

(see Table 2.). Inclusion of organisms on

this initial list was based on disease

outbreak data, published literature

documenting the occurrence of known

or suspected pathogens in water, and

other information. A summary of the

workshop proceedings is in the docket.

Table 2. Initial List of Microorganisms

Developed by EPA for Consideration by

the Workshop on Microbiology and

Public Health

Protozoa

Microsporidia

Toxoplasma

Cyclospora

Acanthamoeba

Naegleria

Isospora

Viruses

Hepatitis E

Astroviruses

Coxsackie/Echo viruses

Adenovirus 40/41

Norwalk virus and other caliciviruses

Rotavirus

Bacteria

Helicobacter pylori

Mycobacterium (MAC)

E. coli O157:H7

Aeromonas hydrophila

Pseudomonas aeruginosa

Acrobacter

Campylobacter

Algal Toxins

Anaebaena flos-aquae

Aphanizomenon flos-aque

Microcystis aeruginosa

Schizothrix calcicola

Workshop participants established a

set of baseline criteria for deciding

whether an organism should appear on

the CCL. These criteria were (1) public

health significance, (2) known

waterborne transmission, (3) occurrence

in source water, (4) effectiveness of

current water treatment, and (5)

adequacy of analytical methods.

Organisms on the EPA list mentioned

above, as well as other organisms that

arose during the discussions, were

evaluated against these criteria.

The CCL published today includes the

list of pathogens identified by the

workshop and subsequently adopted by

the NDWAC as recommendations for the

CCL. Algal toxins were considered to be

of minimal public health significance,

and therefore were not included on the

draft CCL. The following sections

identify the organisms selected, the

rationale for why a pathogen was

included on the CCL, and the rationale

why certain pathogens were not

included.

1. Protozoa

The following protozoa are included

on the CCL: Cyclospora cayetanensis,

Toxoplasma gondii, the two

microsporida—Enterocytozoon and

Septata, and Acanthamoeba. It is

recommended that EPA develop

guidance for controlling Acanthamoeba,

for individuals who wear contact lenses.

The rationale for their selection follows.

C. cayetanensis has caused

waterborne outbreaks in other countries

and one documented outbreak in the

U.S. Thus, it may be a significant public

health risk. Disease symptoms include

watery diarrhea, abdominal cramping,

decreased appetite, and low-grade fever

(Huang et al., 1995). In HIV-infected

persons, the disease may be chronic and

constant (Soave and Johnson, 1995). The

occurrence of this organism in natural

waters and its animal host range are

unknown. However, C. cayetanensis is

transmitted by the fecal-oral route, and

so its presence in water is likely. The

morphology of C. cayetanensis suggests

that the organism is relatively resistant

to disinfectants, but due to its large size

(7–10μm in diameter) it may be removed

satisfactorily by filtration. Cyclospora is

included on the CCL because it has

caused waterborne disease outbreaks in

the U.S. and other countries.

Toxoplasma gondii causes a common

infection of mammals and birds, but the

complete life cycle only occurs in wild
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52199

and domestic cats. The organism infects

a high percentage of the human

population (50 percent in some areas of

the U.S.) but, while subclinical

infections are prevalent, illness is rare

(Fishback, 1992). However, illness may

be severe in fetuses and AIDS patients.

Symptoms include fever, swelling of

lymph glands in the neck, blindness and

mental retardation in fetuses, and

encephalitis in AIDS patients (Fishback,

1992). There have been two documented

outbreaks of toxoplasmosis—in Panama

and British Columbia—both linked

epidemiologically to drinking water.

Chlorination of unfiltered surface waters

is not effective against Toxoplasma

(Benenson et al., 1982). However, due to

their large size (11x12μm), filtration

may be effective in controlling this

organism. Toxoplasma is included on

the CCL because it poses a significant

public health risk, can be transmitted

via the waterborne route, and because a

reasonable potential exists for

completing the needed research in the

next few years for controlling this

organism.

Microsporidia are a large group of

protozoan parasites that are common in

the environment and multiply only

inside cells (Cali, 1991). Five species of

microsporidia have been reported to

cause disease in humans, but only two

are significant in water: Enterocytozoon

bieneusi and Septata intestinalis. Both

are common in people with AIDS

(Goodgame, 1996) and occur chiefly in

AIDS patients (Bryan, 1995), although

infections have been reported in

otherwise healthy persons (Weber et al.,

1994). Symptoms may include diarrhea

(sometimes severe and chronic), and

illness involving the respiratory tract,

urogenital tract, eyes, kidney, liver or

muscles (Bryan, 1995; Goodgame, 1996;

Cali, 1991).

Microsporidia that infect humans

produce small (1–5μm), very resistant

spores (Waller, 1979; Cali, 1991). They

are shed in bodily fluids, including

urine and feces, and thus have a strong

potential to enter water sources.

However, no waterborne outbreak has

yet been reported and there is no

published evidence of waterborne

transmission. Chlorine is probably not

effective against microsporidia, given

that other protozoan spores (cysts,

oocysts) are resistant to chlorine. Thus,

effective filtration and watershed

control may be needed to control this

organism in drinking water. E. bieneusi

and S. intestinalis are included on the

CCL because they pose a significant risk

to immuno-compromised individuals

and may not be removed effectively by

filtration because of their small size (the

spores are somewhat smaller than

Cryptosporidium oocysts).

Acanthamoeba are a group of freeliving amoeba that are common in soil

and water, including drinking water

(Sawyer, 1989; Gonzalez de la Cuesta et

al., 1987). Some Acanthamoeba species

are pathogenic and can cause

inflammation of the eye’s cornea

(especially in individuals who wear soft

or disposable contact lenses (Seal et al.,

1992)), and chronic encephalitis in the

immuno-compromised population

(Kilvington, 1990). To date, no case of

waterborne disease has been reported.

However, Acanthamoeba cysts are

relatively resistant to chlorine (De

Jonkheere and Van der Voorde, 1976).

Because drinking water is not a

suspected route of transmission,

workshop members did not include

Acanthamoeba on their list. However,

as stated above, the Workshop

participants and the NDWAC

recommend that EPA issue guidance to

educate the public about the potential

problem with contact lenses.

Two protozoa that were on the initial

list for consideration developed by EPA

(Naegleria fowleri, Isospara belli), and

two that were not (Entamoeba

histolytica, Blastocystis hominis) were

also considered by the workshop, but

were not included on the CCL. The

reasons for excluding them follow.

N. fowleri is a free-living amoeba,

about 8–15μm in size, found in soil,

water, and decaying vegetation.

Although it is common in many surface

waters, it rarely causes disease. All

disease incidents have been associated

with swimming in natural or manmade,

warm fresh waters; drinking water is not

a suspected route of transmission. The

route of infection is via inhalation rather

than by ingestion. For this reason, it was

not included on the CCL.

I. belli causes gastrointestinal illness,

primarily in AIDS patients and children.

There have been no documented cases

of waterborne transmission. However,

the organism is transmitted by the fecaloral route, so its presence in water is

possible. Filtration is probably effective

in removing I. belli oocysts, given their

large size (30x12μm). This organism was

not included on the CCL because of the

lack of documentation on waterborne

transmission and the belief that not

enough is known about the organism for

developing potential regulations within

a three-year time-frame.

E. histolytica is not considered to be

a significant health problem in the U.S.

In contrast to the situation for Giardia

and Cryptosporidium, animals are not

host reservoirs for E. histolytica. Thus,

the potential for source water

contamination is relatively low,

especially if sewage treatment practices

are adequate. Moreover, the organism

has not caused a significant waterborne

disease outbreak since the early 1950s.

Thirdly, the cyst is large (10–15μm),

slightly larger than a Giardia cyst; thus,

filtration should be effective for

removing this organism. For these

reasons, this organism was not included

on the CCL.

B. hominis was not included on the

CCL because its clinical significance has

not been determined and very little is

known about its potential for

waterborne transmission or its

occurrence in water.

2. Viruses

The following viruses are included on

the CCL: caliciviruses, adenoviruses,

coxsackieviruses, echoviruses, and the

hepatitis A virus. The rationale for their

inclusion follows.

The caliciviruses are a common cause

of acute, but mild, gastrointestinal

illness in the U.S. Between 1980 and

1994, 14 waterborne disease outbreaks

with more than 9,000 associated cases

caused by the Norwalk virus and other

caliciviruses were reported. Thus, their

public health significance is high.

However, because adequate recovery

and assay methods for the caliciviruses

are not yet available, information about

the occurrence of these viruses in water

or the effectiveness of water treatment is

lacking. It is believed that current

research programs might fill the

research gap in the near-term to allow

development of regulations, if

necessary, to control this group of

organisms.

Most of the adenoviruses are

respiratory pathogens. However,

serotypes 40 and 41 are important

causes of gastrointestinal illness,

especially in children. However, all

types may be shed in the feces, and may

be spread by the fecal-oral route.

Although adenoviruses have been

detected in water, data on their

occurrence in water are meager. No

drinking water outbreaks implicating

these viruses have been reported. Both

the respiratory and gastrointestinal

adenoviruses are recommended for the

CCL because of their high public health

significance and data which suggest that

adenoviruses are relatively resistant to

disinfectants.

The coxsackieviruses are readily

found in wastewater and surface water,

and sometimes in drinking water (Hurst,

1991). Although they have not caused a

documented outbreak of waterborne

disease, coxsackieviruses produce a

variety of illnesses in humans,

including the common cold, heart
52200 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

disease, fever, aseptic meningitis,

gastrointestinal problems, and many

more, some of which can be serious

(Melnick, 1992). Coxsackieviruses are

included on the CCL because they are

found more frequently in water than

other viruses and are associated with a

number of illnesses.

The echoviruses, like the

coxsackieviruses, are readily detected in

water, including treated drinking water.

They are associated with milder

illnesses than the coxsackieviruses, and

have not caused a documented

outbreak. Echoviruses are included on

the CCL because, like the

coxsackieviruses, they are found more

frequently in water than other viruses

and are associated with a number of

illnesses.

The hepatitis A virus has caused at

least 11 waterborne disease outbreaks of

infectious hepatitis since 1980.

Therefore, it has a high public health

significance. The virus has been found

in contaminated drinking water, and is

somewhat resistant to chlorination

(Peterson et al., 1983). For these reasons,

it is also included on the CCL.

Three viruses that were on the initial

list for consideration developed by EPA

(rotaviruses, hepatitis E virus, and

astroviruses) and two that were not

(picobivirna and picotrivirna) were also

considered by the workshop

participants, but were not included on

the CCL. The reasons for not including

them follow.

Rotaviruses cause acute

gastroenteritis, primarily in children.

Almost all children have been infected

at least once by the age of five years

(Parsonnet, 1992), and in developing

countries, rotavirus infections are a

major cause of infant mortality.

Rotaviruses are spread by fecal-oral

transmission and have been found in

ambient water, ground water, and tap

water (Gerba et al., 1985; Gerba, 1996).

However, only a single waterborne

disease outbreak has been reported in

the U.S. and only several have been

documented outside the U.S. (Gerba et

al., 1985). Rotaviruses are readily

inactivated by chlorine, chlorine

dioxide, and ozone, but apparently not

by monochloramine (Berman and Hoff,

1984; Chen and Vaughn, 1990, Vaughn

et al., 1986; 1987). Rotaviruses were not

included on the CCL because they are

not regarded as an important public

health problem in the U.S., and because

of their vulnerability to disinfectants.

Hepatitis E virus is an important agent

of hepatitis in underdeveloped

countries, but apparently not in the U.S.

The virus is transmitted by the fecal-oral

route (Dreesman and Reyes, 1992) and

probably a majority of cases are

waterborne. Even though the disease is

apparently not a health concern in the

U.S., one investigation found that 21.3%

of blood donors in Baltimore were seropositive (Thomas et al., 1997),

suggesting previous exposure to the

organism. Infections are mild and selflimiting except for pregnant women,

who have a fatality rate of up to 39%.

No data from disinfection studies have

been published. Hepatitis E virus was

not included on the CCL because it is

not regarded as a significant public

health threat in the U.S., and because

current sewage treatment practices are

judged sufficient to eliminate risk of

waterborne transmission.

Astroviruses are found throughout the

world and cause illness in 1–3 year old

children and in AIDS patients, but

rarely in healthy adults (Kurtz and Lee,

1987; Grohmann et al., 1993).

Symptoms are mild and typical of

gastrointestinal illness, but the disease

is more severe and persistent in the

severely immuno-compromised.

Astroviruses are transmitted by the

fecal-oral route and have been detected

in water and have been associated

anecdotally with waterborne disease

outbreaks (Cubitt, 1991; Pinto et al.,

1996). The astroviruses were not

included on the CCL because of the

mildness of the illness and the lack of

adequate documentation about the

occurrence in water and potential as a

waterborne disease agent.

The picobivirna and picotrivirna

viruses are of public health significance

outside the U.S., and are not regarded as

being a waterborne problem in the U.S.

and are adequately removed from

effluent water by current sewage

treatment practices. Picobivirna and

picotrivirna viruses were not included

on the CCL for these reasons.

3. Bacteria

The following bacteria are included

on the CCL: Helicobacter pylori,

Legionella, Mycobacterium avium

complex, and Aeromonas hydrophila.

The rationale for their identification

follows.

H. pylori has been closely associated

with peptic ulcers, gastric carcinoma,

and gastritis (Peterson, 1991; Nomura et

al., 1991; Parsonnet et al., 1991, Cover

and Blaser, 1995). Data about its

distribution in the environment are

scarce, but the organism has been found

in sewage (Sutton et al., 1995) and has

been linked to ambient water and

drinking water by epidemiological tests

and other means (Klein et al., 1991;

Shahamat et al., 1992; Shahamat et al.,

1993; Hulten et al., 1996). The number

of people in the U.S. that have

antibodies against H. pylori, and thus

have been exposed to the organism, is

high. Helicobacter is thought to be

vulnerable to disinfectants. H. pylori is

included on the CCL because of its

public health significance in the U.S.

and the possibility of waterborne

transmission.

Legionella pneumophila and other

Legionella species cause Legionnaires

Disease (a type of pneumonia) and

Pontiac Fever (a mild, nonpneumonic

illness). Legionnaires Disease, which

has a 15% mortality rate, typically

results from the inhalation of aerosols of

water containing the organism.

Legionella are abundant and naturally

occurring in surface water; thus they are

not necessarily associated with fecal

contamination. They have also been

detected in ground water. Small

numbers can occur in the finished

waters of systems employing full

treatment (U.S. EPA, 1989b) and can

colonize plumbing systems, especially

warm ones. Aerosols from fixtures, such

as showerheads, may cause the disease

via inhalation. Aerosols from cooling

towers, hot tubs, and pools have also

caused a number of outbreaks. Direct

person-to-person spread has not been

documented (Yu et al., 1983). Ozone,

chlorine dioxide, and ultraviolet light

are effective in controlling Legionella,

but data for chlorine are inconsistent

(States et al., 1990). Legionella in

surface water are already regulated

under EPA’s Surface Water Treatment

Regulations (40 CFR part 141, subpart

H). Legionella in ground water is

included on the CCL because of their

public health significance in the U.S.

and the possibility of waterborne

transmission via ground water.

Mycobacterium avium complex

(MAC; also known as the

Mycobacterium avium intracellulare

complex) is common in the

environment and can colonize water

systems and plumbing systems (du

Moulin and Stottmeier, 1986; du Moulin

et al., 1988). It is known to cause

pulmonary disease and other diseases,

especially in individuals with a

weakened immune system (e.g., AIDS

patients). Drinking water has been

epidemiologically linked to infections

in hospital patients (du Moulin and

Stottmeier, 1986). MAC is relatively

resistant to chlorine disinfection

(Pelletier et al., 1988). MAC is included

on the CCL because of its high public

health significance, its ability to

colonize on pipes, and its relative

resistance to chlorine.

Aeromonas hydrophila can cause

wound infections and septicemia in

people with a weakened immune

system, and some evidence suggests that

it causes gastrointestinal disease in
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52201

healthy people. The organism is

common in water and is not necessarily

associated with fecal contamination. It

is vulnerable to disinfectants. A.

hydrophila is included on the CCL

primarily because it is common in

source water.

Pseudomonas aeruginosa is a freeliving bacterium that is common in

water. People at risk include patients

with profound neutropenia, cystic

fibrosis, severe burns, and those with

foreign devices installed (Hardalo and

Edberg, 1997). The organism has also

caused numerous outbreaks of

dermatitis in recreational waters, e.g.,

pools, whirlpools, and hot tubs (Kramer

et al., 1996). Because of differing

opinions among the microbiologists

who participated in the workshop about

its public health significance and its

potential health risk via the waterborne

route, a decision could not reach on

whether to include P. aeruginosa on

their list. Rather, it was recommended

that EPA conduct a complete literature

search on the topic before the Agency

decides whether to include this

organism on the final list. The literature

search will be conducted prior to

publishing the final CCL.

Four bacteria that were on the initial

list for consideration developed by EPA

(Escherichia coli O157:H7,

Campylobacter, Arcobacter, and the

cyanobacteria) and four that were not

(Salmonella, Shigella, Vibrio cholerae

and other Vibrio species, and Yersinia

enterocolitica) were also considered by

the workshop, but were not included on

the CCL. The reasons for excluding

them follow.

E. coli O157:H7, Campylobacter,

Salmonella, Shigella, V. cholerae, and

Y. enterocolitica have all caused

waterborne disease in the U.S. and are

regarded as significant health risks.

They were not included on the CCL

because current treatment practices

were deemed to be adequate in

controlling these organisms. Arcobacter

was not included on the CCL because its

health significance and the possibility of

waterborne transmission are unknown,

and because current treatment practices

were judged likely in controlling this

organism.

Cyanobacteria (also known as bluegreen algae) are generally not

considered an important health risk.

However, certain species may produce

neurotoxins (which affects the nervous

system), hepatotoxins (which affects the

liver), and other types of toxins which,

if ingested at high enough

concentrations, may be harmful. High

concentrations of toxins associated with

a bloom of Schizothrix calcicola may

have been responsible for an outbreak of

gastroenteritis in 1975 (Lippy and Erb,

1976). However, little evidence exists

that ambient levels found in most water

supplies pose a health risk to the normal

population. The cyanobacteria was not

included on the CCL because the

problem is thought to be best handled

through good watershed management

practices to prevent algal growth in

source waters.

4. Microbiological Indicators

Indicators of fecal contamination or of

pathogens were not addressed at the

workshop. EPA is involved, however, in

a project with the International Life

Sciences Institute to begin an evaluation

of which microbiological indicators are

most appropriate for various types of

environmental waters. Currently, the

Agency uses total coliform bacteria as

the sole indicator of microbiological

drinking water quality.

5. Future Activities Planned for

Microbiological Contaminants and the

CCL

EPA is attempting to develop a more

formal framework for identifying,

selecting and prioritizing pathogens

(and their indicators) for research and

possible regulation, and for future CCLs.

To date, the identification of pathogens

for the CCL has been relatively informal.

In contrast, a more objective approach

for contaminant identification and

selection in the future may be based on

a numerical scoring procedure such that

contaminants with higher scores would

have greater priority for regulation,

research and guidance development

than those that have lower scores.

6. Possible Impacts From Other

Regulatory Activity

Pathogens that are included on the

final CCL, will be candidates for

regulatory control, guidance

development, and additional research

over the next five years. These

organisms may be controlled, however,

by regulations currently under

development such as the Enhanced

Surface Water Treatment Rule, the

Ground Water Disinfection Rule. If

pathogens on the CCL are determined to

be controlled by these regulations, they

will be withdrawn from the CCL.

C. Chemical Contaminants Identified for

the Draft CCL

As stated earlier, the NDWAC

Working Group on Occurrence &

Contaminant Selection played an

integral part in developing the draft CCL

presented in today’s notice. At the

initial Working Group meeting held on

April 3–4, 1997, the Agency proposed a

number of lists of contaminants as a

logical starting point for developing the

draft CCL. Some lists originate from

other Agency programs, while others

were developed in anticipation of future

DWPLs. The Agency also proposed that

the initial list would need to be reduced

to a smaller list of priority contaminants

that would become the CCL.

In April, the Working Group

identified 32 contaminants thought to

be those most important for inclusion

on the first CCL, other contaminants for

initial consideration, and criteria to be

used to evaluate and screen all

contaminants initially considered.

During this April meeting, and two

subsequent meetings, held on June 23

and July 17, 1997, the Working Group

developed these recommendations

which were approved by the full

NDWAC, and subsequently adopted by

the Agency, to use in screening the

initial list to the contaminants to today’s

draft CCL. Summaries of the meetings

are provided in the docket. The

following sections provide the rationale

for the initial list of contaminants

considered and a summary of the

development and application of the

criteria used to evaluate the

contaminants on the initial list to

develop the draft CCL.

1. The Initial List of Chemical

Contaminants Considered

Ten lists of chemical contaminants

were considered to be logical starting

points for developing the first CCL. Of

the ten, eight lists were ultimately

combined to serve as the initial list of

contaminants to be considered for the

CCL. Some contaminants appear on

more than one of the eight lists. The

initial list of contaminants considered,

as well as those eliminated or deferred

from consideration, are in Table 3. The

following sections provide a description

of each of the lists and the rationale

behind including it with, or excluding

it from, the initial list of contaminants

considered.
52202 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

TABLE 3.—INITIAL LIST OF CHEMICAL CONTAMINANTS CONSIDERED DURING DEVELOPMENT OF THE DRAFT CCL

Contaminant CAS No.

Contaminant lists considered

1991

DWPL

(1)

Health

advisories

(2)

IRIS

(3) PWS (4) CERCLA(5)

Stakeholder

summary

list (6)

TRI list

(7)

OPP ranking

(8)

Contaminants Identified as Initial Candidates for the CCL during April 3–4, 1997 Working Group Meeting

Inorganics:

Aluminum ................................. 7429–90–5 ✔ ✔ .............. .............. .................. ✔ ✔ ..................

Zinc .......................................... 7440–66–6 ✔ ✔ .............. .............. .................. .................. ✔ ..................

Pesticides:

Acetochlor ................................ 34256–82–1 .............. ✔ .............. .............. .................. ✔ .............. ✔

Alachlor ESA ............................ .................... .............. ................ .............. .............. .................. ✔ .............. ✔

Butylate .................................... 2008–41–5 .............. ✔ ✔ .............. .................. .................. .............. ✔

Chlorpyrifos .............................. 2921–88–2 .............. ✔ ✔ .............. .................. ✔ .............. ..................

DCPA (Dacthal) ....................... 1861–32–1 ✔ ✔ .............. .............. .................. ✔ .............. ..................

DCPA di-acid degradate .......... 2136–79–0 ✔ ................ .............. .............. .................. .................. .............. ✔

DCPA mono-acid degradate .... 887–54–7 ✔ ................ .............. .............. .................. .................. .............. ..................

DDE .......................................... 72–55–9 .............. ................ ✔ .............. ✔ .................. .............. ..................

Diazinon ................................... 333–41–5 .............. ✔ .............. .............. .................. .................. .............. ✔

Diuron ....................................... 330–54–1 .............. ✔ .............. .............. .................. ✔ .............. ✔

Endosulfan ............................... 115–29–7 .............. ................ ✔ .............. .................. ✔ .............. ✔

EPTC (s-ethyl-dipropylthio-carbamate) ................................ 759–94–4 .............. ................ ✔ .............. .................. .................. .............. ✔

Malathion .................................. 121–75–5 .............. ✔ ✔D .............. .................. .................. .............. ..................

Methyl parathion ...................... 298–00–0 .............. ✔ ✔ .............. .................. .................. .............. ..................

Metolachlor ............................... 51218–45–2 ✔ ✔ ✔ .............. .................. ✔ .............. ✔

Metribuzin ................................. 21087–64–9 ✔ ✔ ✔ .............. .................. ✔ .............. ✔

Prometon .................................. 1610–18–0 ✔ ✔ .............. .............. .................. .................. .............. ✔

Propanil .................................... 709–98–8 .............. ................ ✔ .............. .................. .................. .............. ..................

Tebuthiuron .............................. 34014–18–1 .............. ✔ .............. .............. .................. .................. .............. ..................

Terbacil .................................... 5902–51–2 .............. ✔ .............. .............. .................. .................. .............. ✔

Triazines (total) (9) ................... .................... .............. ................ .............. .............. .................. ✔ .............. ..................

Triazine degradation products

(9), atrazine-desethyl ............ 6190–65–4 .............. ................ .............. .............. .................. ✔ .............. ✔

Triazines (unregulated) (9) ...... .................... .............. ................ .............. .............. .................. ✔ .............. ..................

Trifluralin ................................. 1582–09–8 ✔ ✔ ✔ .............. .................. .................. .............. ✔

Organics:

2-methyl-Phenol (o-cresol) ....... 95–48–7 .............. ................ ✔ .............. .................. .................. .............. ..................

Acetone .................................... 67–64–1 .............. ................ ✔ .............. .................. .................. .............. ..................

Ethylene glycol ......................... 107–21–1 .............. ✔ ✔ .............. .................. .................. ✔ ..................

Methyl ethyl ketone (MEK) ...... 78–93–3 ✔ ✔ .............. .............. .................. ✔ ✔ ..................

Methyl-t-butyl ether (MTBE) ... 1634–04–4 ✔ ✔ .............. .............. .................. ✔ ✔ ..................

Nitrobenzene ............................ 98–95–3 ✔ ................ ✔ .............. .................. .................. .............. ..................

Phenol ...................................... 108–95–2 .............. ✔ ✔ .............. .................. .................. ✔ ..................

Additional Contaminants Considered for the CCL

Inorganics:

Ammonia .................................. 7664–41–7 .............. ✔ .............. .............. .................. ✔ ✔ ..................

Ammonium nitrate .................... 6484–52–2 .............. ................ .............. .............. .................. .................. ✔ ..................

Ammonium sulfamate .............. 7773–06–0 .............. ✔ .............. .............. .................. .................. .............. ..................

Ammonium sulfate ................... 7783–20–2 .............. ✔ .............. .............. .................. .................. ✔ ..................

Boron ........................................ 7440–42–8 ✔ ✔ .............. .............. .................. .................. .............. ..................

Carbon disulfide ....................... 75–15–0 .............. ................ .............. .............. .................. .................. ✔ ..................

Carbonyl sulfide ....................... 463–58–1 .............. ................ .............. .............. .................. .................. ✔ ..................

Cobalt ....................................... 7440–48–4 .............. ................ .............. .............. .................. .................. ✔ ..................

Hydrochloric acid ..................... 7647–01–0 .............. ................ .............. .............. .................. .................. ✔ ..................

Hydrogen fluoride ..................... 7664–39–3 .............. ................ .............. .............. .................. .................. ✔ ..................

Manganese .............................. 7439–96–5 ✔ ................ .............. .............. ✔ ✔ ✔ ..................

Metam-sodium ......................... 137–42–8 .............. ................ ✔ .............. .................. .................. .............. ..................

Molybdenum ............................. 7439–98–7 ✔ ✔ .............. .............. .................. .................. .............. ..................

Phosphoric acid ....................... 7664–38–2 .............. ................ .............. .............. .................. .................. ✔ ..................

Phosphorous ............................ 7723–14–0 .............. ✔ .............. .............. ✔ .................. ✔ ..................

Sodium ..................................... 7440–23–5 .............. ✔ .............. .............. .................. .................. .............. ..................

Strontium .................................. 7440–24–6 ✔ ✔ .............. .............. .................. .................. .............. ..................

Vanadium ................................. 7440–62–2 ✔ ✔ .............. .............. .................. .................. .............. ..................

Pesticides:

1,3-Dichloropropene (telone or

1,3-D) .................................... 542–75–6 ✔ ✔ ✔ .............. .................. ✔ .............. ✔

2,4,5-T ...................................... 93–76–5 ✔ ✔ .............. .............. .................. .................. .............. ..................

2,4-DB ...................................... 94–82–6 .............. ................ .............. .............. .................. .................. .............. ✔

2,4-DP ...................................... 120–36–5 .............. ................ .............. .............. .................. ✔ .............. ..................
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52203

TABLE 3.—INITIAL LIST OF CHEMICAL CONTAMINANTS CONSIDERED DURING DEVELOPMENT OF THE DRAFT CCL—

Continued

Contaminant CAS No.

Contaminant lists considered

1991

DWPL

(1)

Health

advisories

(2)

IRIS

(3) PWS (4) CERCLA(5)

Stakeholder

summary

list (6)

TRI list

(7)

OPP ranking

(8)

4-Nitrophenol (p-Nitrophenol) .. 100–02–7 ✔ ✔ .............. .............. .................. .................. .............. ..................

Acephate .................................. 30560–19–1 .............. ✔ .............. .............. .................. ✔ .............. ..................

Acifluofen ................................. 50594–66–6 ✔ ✔ .............. .............. .................. ✔ .............. ✔

Aldrin ........................................ 309–00–2 .............. ✔ .............. .............. ✔ .................. ..............

Ametryn .................................... 834–12–8 .............. ✔ .............. .............. .................. ✔ .............. ✔

Amitraz ..................................... 33089–61–1 .............. ................ .............. .............. .................. ✔ .............. ..................

Asulam ..................................... 3337–71–1 ✔ ................ .............. .............. .................. .................. .............. ✔

Bensulfuron methyl .................. .................... .............. ................ .............. .............. .................. .................. .............. ✔

Bentazon .................................. 25057–89–0 ✔ ✔ .............. .............. .................. .................. .............. ✔

Benzidine ................................. 92–87–5 .............. ................ .............. .............. ✔ .................. .............. ..................

Bromacil ................................... 314–40–9 ✔ ✔ .............. .............. .................. ✔ .............. ✔

Bromoxynil ............................... 1689–84–5 .............. ................ ✔ .............. .................. .................. .............. ✔

Cadre ....................................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Caprolactum ............................. 105–60–2 .............. ................ ✔ .............. .................. .................. .............. ..................

Captan ...................................... 133–06–2 .............. ................ ✔ .............. .................. .................. .............. ..................

Carbaryl .................................... 63–25–2 .............. ✔ ✔ .............. .................. .................. .............. ..................

Carboxin ................................... 5234–68–4 .............. ✔ .............. .............. .................. .................. .............. ..................

Chloramben .............................. 133–90–4 .............. ✔ .............. .............. .................. ✔ .............. ..................

Chlorimuron ethyl ..................... 90982–32–4 .............. ................ .............. .............. .................. .................. .............. ✔

Chlorothalonil ........................... 1897–45–6 .............. ✔ ✔ .............. .................. .................. .............. ..................

Chlorsulfuron ............................ 64902–72–3 .............. ................ .............. .............. .................. .................. .............. ✔

Clopyralid ................................. 1702–17–6 .............. ................ .............. .............. .................. ✔ .............. ..................

Cyanazine ................................ 21725–46–2 ✔ ✔ ✔ .............. .................. ✔ .............. ✔

Cyromazine .............................. 66215–27–8 ✔ ................ .............. .............. .................. ✔ .............. ..................

DDD ......................................... 72–54–8 .............. ................ .............. .............. ✔ .................. .............. ..................

DDT .......................................... 50–29–3 .............. ................ ✔ .............. ✔ .................. .............. ..................

Diazinon—oxypyrimidine .......... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Dicamba ................................... 1918–00–9 ✔ ✔ .............. .............. .................. ✔ .............. ✔

Dichlobenil ................................ 1194–65–6 .............. ................ .............. .............. .................. ✔ .............. ..................

Dieldrin ..................................... 60–57–1 .............. ✔ .............. .............. ✔ ✔ .............. ..................

Dimethoate ............................... 60–51–5 .............. ................ ✔ .............. .................. ✔ .............. ..................

Dimethrin .................................. 70–38–2 .............. ✔ .............. .............. .................. .................. .............. ..................

Diphenamid .............................. 957–51–7 .............. ✔ .............. .............. .................. .................. .............. ..................

Disulfoton ................................. 298–04–4 .............. ✔ .............. .............. ✔ .................. .............. ..................

Endosulfan sulfate ................... 1031–07–8 .............. ................ .............. .............. ✔ .................. .............. ..................

Ethalfluralin .............................. 55283–68–6 .............. ................ .............. .............. .................. .................. .............. ✔

Ethofumesate ........................... 26225–79–6 .............. ................ .............. .............. .................. ✔ .............. ..................

Ethoprop ................................... 13194–48–4 .............. ................ .............. .............. .................. ✔ .............. ..................

Ethylenethiourea (ETU) ........... 96–45–7 ✔ ✔ .............. .............. .................. .................. .............. ✔

Fenamiphos ............................. 22224–92–6 .............. ✔ .............. .............. .................. ✔ .............. ✔

Fluazifop-p-butyl ....................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Fluometuron ............................. 2164–17–2 .............. ✔ .............. .............. .................. .................. .............. ✔

Fomesafen ............................... 72178–02–0 ✔ ................ .............. .............. .................. .................. .............. ..................

Fonofos .................................... 944–22–9 .............. ✔ ✔ .............. .................. ✔ .............. ..................

Halofenozide ............................ .................... .............. ................ .............. .............. .................. .................. .............. ✔

Halosulfuron ............................. .................... .............. ................ .............. .............. .................. .................. .............. ✔

Hexazinone .............................. 51235–04–2 .............. ................ .............. .............. .................. ✔ .............. ✔

Imazamethabenz ...................... 81405–85–8 .............. ................ .............. .............. .................. .................. .............. ✔

Imazapyr .................................. .................... .............. ................ .............. .............. .................. .................. .............. ✔

Imazaquin ................................. 81335–37–7 .............. ................ .............. .............. .................. .................. .............. ✔

Imazethapyr ............................. 81335–77–5 .............. ................ .............. .............. .................. ✔ .............. ✔

Imidacloprid .............................. .................... .............. ................ .............. .............. .................. ✔ .............. ..................

Lactofen ................................... 77501–63–4 ✔ ................ .............. .............. .................. .................. .............. ..................

Linuron ..................................... 330–55–2 .............. ................ ✔ .............. .................. .................. .............. ..................

Maneb (ETU precursor) ........... 12427–38–2 .............. ................ ✔ .............. .................. .................. .............. ..................

MCPA ....................................... 94–74–6 .............. ✔ .............. .............. .................. ✔ .............. ..................

MCPP ....................................... 93–65–2 .............. ................ .............. .............. .................. ✔ .............. ..................

Metalaxyl .................................. 57837–19–1 ✔ ................ .............. .............. .................. .................. .............. ..................

Methazole ................................. 20354–26–1 .............. ................ .............. .............. .................. .................. .............. ✔

Methomyl .................................. 16752–77–5 ✔ ................ ✔ .............. .................. ✔ .............. ..................

Metsulfuron methyl ................... 74223–64–6 .............. ................ .............. .............. .................. ✔ .............. ✔

Molinate .................................... 2212–67–1 .............. ................ ✔ .............. .................. .................. .............. ..................

MSMA ...................................... 2163–80–6 .............. ................ .............. .............. .................. .................. .............. ✔

Napropamide ............................ 15299–99–7 .............. ................ .............. .............. .................. ✔ .............. ..................

Nicosulfuron ............................. .................... .............. ................ .............. .............. .................. .................. .............. ✔

Norflurazon ............................... 27314–13–2 .............. ................ .............. .............. .................. ✔ .............. ✔
52204 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

TABLE 3.—INITIAL LIST OF CHEMICAL CONTAMINANTS CONSIDERED DURING DEVELOPMENT OF THE DRAFT CCL—

Continued

Contaminant CAS No.

Contaminant lists considered

1991

DWPL

(1)

Health

advisories

(2)

IRIS

(3) PWS (4) CERCLA(5)

Stakeholder

summary

list (6)

TRI list

(7)

OPP ranking

(8)

Paraquat ................................... 4685–14–7 .............. ✔ ✔ .............. .................. .................. .............. ✔

Pendimethalin .......................... 40487–42–1 .............. ................ ✔ .............. .................. .................. .............. ✔

Primisulfuron methyl ................ .................... .............. ................ .............. .............. .................. .................. .............. ✔

Prometryn ................................. 7287–19–6 .............. ................ .............. .............. .................. .................. .............. ✔

Pronamide ................................ 23950–58–5 .............. ✔ .............. .............. .................. .................. .............. ..................

Propachlor ................................ 1918–16–7 .............. ✔ .............. .............. .................. ✔ .............. ✔

Propargite ................................. 2312–35–8 .............. ................ ✔ .............. .................. .................. .............. ..................

Propazine ................................. 139–40–2 .............. ✔ ✔ .............. .................. .................. .............. ✔

Propham ................................... 122–42–9 .............. ✔ .............. .............. .................. .................. .............. ..................

Propiconazole .......................... 60207–90–1 .............. ................ .............. .............. .................. ✔ .............. ..................

Propoxur (Baygon) ................... 114–26–1 .............. ✔ .............. .............. .................. .................. .............. ..................

Prosulfuron ............................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Pyrazon .................................... 1698–60–8 .............. ................ .............. .............. .................. ✔ .............. ..................

Pyrithiobac-Na .......................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Rimsulfuron .............................. .................... .............. ................ .............. .............. .................. .................. .............. ✔

Sethoxydim .............................. 74051–80–2 .............. ................ .............. .............. .................. .................. .............. ✔

Sulfentrazone ........................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Sulfometuron methyl ................ 74222–97–2 .............. ................ .............. .............. .................. .................. .............. ✔

Tebufenozide ........................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Terbufos ................................... 13071–79–9 .............. ✔ ✔ .............. .................. ✔ .............. ..................

Terbufos sulfone ...................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Thiazopyr ................................. .................... .............. ................ .............. .............. .................. .................. .............. ✔

Thifensulfuron methyl ............... 79277–27–3 .............. ................ .............. .............. .................. .................. .............. ✔

Thiodicarb ................................ 59669–26–0 ✔ ................ .............. .............. .................. .................. .............. ..................

Triallate .................................... 2303–17–5 .............. ................ ✔ .............. .................. .................. .............. ..................

Triasulfuron .............................. 82097–50–5 .............. ................ .............. .............. .................. ✔ .............. ✔

Triberuron methyl ..................... .................... .............. ................ .............. .............. .................. .................. .............. ✔

Vernolate .................................. 1929–77–7 .............. ................ .............. .............. .................. .................. .............. ✔

Organics:

1,1,1,2-tetra-chloroethane ........ 630–20–6 ✔ ✔ .............. .............. .................. .................. .............. ..................

1,1,1-trichloropropane .............. .................... .............. ✔ .............. .............. .................. .................. .............. ..................

1,1,2,2-tetra-chloroethane ........ 79–34–5 ✔ ✔ .............. .............. .................. .................. .............. ..................

1,1-dichloro-ethane .................. 75–34–3 ✔ ................ .............. .............. .................. .................. .............. ..................

1,1-dichloro-propene ................ 563–58–6 ✔ ✔ .............. .............. .................. .................. .............. ..................

1,2,3-trichloro-propane ............. 96–18–4 ✔ ✔ .............. .............. .................. .................. .............. ..................

1,2,4-trimethylbenzene ............. 95–63–6 .............. ................ .............. .............. .................. .................. ✔ ..................

1,2-diphenyl-hydrazine ............. 122–66–7 ✔ ................ .............. .............. .................. .................. .............. ..................

1,3,5-trichlorobenzene ............. 108–70–3 .............. ✔ .............. .............. .................. .................. .............. ..................

1,3-butadiene ........................... 106–99–0 .............. ................ .............. .............. .................. .................. ✔ ..................

1,3-dichloro-benzene ............... 541–73–1 ✔ ................ .............. .............. .................. .................. .............. ..................

1,3-dichloropropane ................. 142–28–9 ✔ ✔ .............. .............. .................. .................. .............. ..................

1,3-dichloropetan-3–OL, .......... .................... .............. ................ .............. ✔ .................. .................. .............. ..................

1,3-dinitrobenzene ................... 99–65–0 .............. ✔ .............. .............. .................. .................. .............. ..................

1,4-dioxane .............................. 123–91–1 .............. ✔ ✔ .............. .................. ✔ ✔ ..................

1,4-dithiane .............................. 505–29–3 .............. ✔ .............. .............. .................. .................. .............. ..................

1-methyl -2-Pyrrolidinone ......... 872–50–4 .............. ................ .............. ✔ .................. .................. .............. ..................

2,2-dichloro-propane ................ 594–20–7 ✔ ✔ .............. .............. .................. .................. .............. ..................

2,4,6-trichlorophenol ................ 88–06–2 .............. ✔ .............. .............. .................. .................. .............. ..................

2,4-dichlorophenol .................... 120–83–2 .............. ✔ .............. .............. .................. .................. .............. ..................

2,4-dinitrophenol ...................... 51–28–5 ✔ ................ .............. .............. .................. .................. .............. ..................

2,4-dinitrotoluene ..................... 121–14–2 ✔ ✔ .............. .............. .................. .................. .............. ..................

2,6-dinitrotoluene ..................... 606–20–2 ✔ ✔ .............. .............. .................. .................. .............. ..................

2,6-di-tert-butyl-pbenzoquinone (DTBB), (2,6-

bis(1,1-dimethylethyl)2,5-

cyclohexadiene-1,4-dione) ... 719–22–2 .............. ................ .............. ✔ .................. .................. .............. ..................

2-methanoxy ethanol ............... 109–86–4 .............. ................ .............. .............. .................. .................. ✔ ..................

3-chloro-1-propene ................... 107–05–1 .............. ................ .............. ✔ .................. .................. .............. ..................

4,4′-isopropylidenediphenol

(bisphenol A) ........................ 80–05–7 .............. ................ .............. .............. .................. .................. ✔ ..................

4-methyl-Phenol (p-cresol) ....... 106–44–5 .............. ................ .............. ✔ .................. .................. .............. ..................

Acetaldehyde ........................... 75–07–0 .............. ................ .............. .............. .................. .................. ✔ ..................

Acetamide ................................ 60–35–5 .............. ................ .............. ✔ .................. .................. .............. ..................

Acetonitrile ............................... 75–05–8 .............. ................ .............. .............. .................. .................. ✔ ..................

Acrylic acid ............................... 79–10–7 .............. ................ .............. .............. .................. .................. ✔ ..................

Acrylonitrile ............................... 107–13–1 ✔ ✔ .............. .............. .................. .................. ✔ ..................
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52205

TABLE 3.—INITIAL LIST OF CHEMICAL CONTAMINANTS CONSIDERED DURING DEVELOPMENT OF THE DRAFT CCL—

Continued

Contaminant CAS No.

Contaminant lists considered

1991

DWPL

(1)

Health

advisories

(2)

IRIS

(3) PWS (4) CERCLA(5)

Stakeholder

summary

list (6)

TRI list

(7)

OPP ranking

(8)

Aniline ...................................... 62–53–3 .............. ................ ✔ .............. .................. .................. .............. ..................

Azulene .................................... 275–51–4 .............. ................ .............. ✔ .................. .................. .............. ..................

Benzaldehyde .......................... 100–52–7 .............. ................ .............. ✔ .................. .................. .............. ..................

Benzaldehyde, 3-hydroxy- ....... 100–83–4 .............. ................ .............. ✔ .................. .................. .............. ..................

Benzamide, N-acetyl- ............... 1575–95–7 .............. ................ .............. ✔ .................. .................. .............. ..................

Benzamide,N-ethyl- .................. 614–17–5 .............. ................ .............. ✔ .................. .................. .............. ..................

Benzeneacetamide, N,N-dimethyl-a-phenyl- ................... .................... .............. ................ .............. ✔ .................. .................. .............. ..................

Benzeneacetonitrile .................. 140–29–4 .............. ................ .............. ✔ .................. .................. .............. ..................

Benzofluoranthene ................... 56832–73–6 .............. ................ .............. .............. ✔ .................. .............. ..................

Bis-2-chloroisopropyl ether ...... 39638–32–9 .............. ✔ .............. .............. .................. .................. .............. ..................

Bornyl acetate .......................... 76–49–3 .............. ................ .............. ✔ .................. .................. .............. ..................

Bromobenzene ......................... 108–86–1 ✔ ✔ .............. .............. .................. .................. .............. ..................

Catechol ................................... 120–80–9 .............. ................ .............. .............. .................. .................. ✔ ..................

Chlorodifluoromethane HCFC–

22 .......................................... 75–45–6 .............. ................ .............. .............. .................. .................. ✔ ..................

Chlorophenol 2- ....................... 95–57–8 .............. ✔ .............. .............. .................. .................. .............. ..................

Creosote ................................... 8001–58–9 .............. ................ .............. .............. ✔ .................. .............. ..................

Cresol mixed isomers .............. 1319–77–3 .............. ................ .............. .............. .................. .................. ✔ ..................

Cymene p-(pisopropyltolunene) ................ 99–87–6 .............. ✔ .............. .............. .................. .................. .............. ..................

Decabromodiphenyl oxide ....... 1163–19–5 .............. ................ .............. .............. .................. .................. ✔ ..................

Dibenzo(a,h)anthracene ........... 53–70–3 .............. ................ .............. .............. ✔ .................. .............. ..................

Dichloro CFC-114 .................... 76–14–2 .............. ................ .............. .............. .................. .................. ✔ ..................

Dichloro-difluoromethane ......... 75–71–8 ✔ ✔ .............. .............. .................. ✔ ✔ ..................

DichloroHCFC141-b ................. 171–00–6 .............. ................ .............. .............. .................. .................. ✔ ..................

Diethanolamine ........................ 111–42–2 .............. ................ .............. .............. .................. .................. ✔ ..................

Diisoamylene ............................ .................... .............. ................ .............. ✔ .................. .................. .............. ..................

Diisopropyl methylphosphonate 1445–75–6 .............. ✔ .............. .............. .................. .................. .............. ..................

Dimethyl methylphosphonate ... 756–79–6 .............. ✔ .............. .............. .................. .................. .............. ..................

Diphenylamine ......................... 122–39–4 .............. ✔ .............. .............. .................. .................. .............. ..................

Ethanone, 1-[4-(hydroxy-1-

methylethyl) phenyl]- ............ .................... .............. ................ .............. .............. .................. .................. .............. ..................

Ethyl ether ................................ 60–29–7 .............. ................ ✔ .............. .................. .................. .............. ..................

Ethylene ................................... 74–85–1 .............. ................ .............. .............. .................. .................. ✔ ..................

Fog oil ...................................... .................... .............. ✔ .............. .............. .................. .................. .............. ..................

Formaldehyde .......................... 50–00–0 .............. ✔ ✔ .............. .................. .................. ✔ ..................

Formic acid .............................. 64–18–6 .............. ................ .............. .............. .................. .................. ✔ ..................

Freon 113 ................................. 76–13–1 .............. ................ .............. .............. .................. .................. ✔ ..................

Glufosinate ammonium ............ 77182–82–2 .............. ................ .............. .............. .................. ✔ .............. ..................

Glycol ethers ............................ 111–46–6 .............. ................ .............. .............. .................. .................. ✔ ..................

HCFC-11142-b ......................... .................... .............. ................ .............. .............. .................. .................. ✔ ..................

Hexachloro-butadiene .............. 87–68–3 ✔ ✔ .............. .............. ✔ .................. .............. ..................

Hexachloroethane .................... 67–72–1 ✔ ✔ .............. .............. .................. .................. .............. ..................

Hexanoic acid .......................... 142–62–1 .............. ................ .............. ✔ .................. .................. .............. ..................

Hexazinone .............................. 51235–04–2 .............. ✔ .............. .............. .................. .................. .............. ..................

HMX (cyclotetramethylene

tetranitramine) ...................... 2691–41–0 .............. ✔ .............. .............. .................. .................. .............. ..................

Hydroperoxide, 1,1-

dimethylethy ......................... l75–91–2 .............. ................ .............. ✔ .................. .................. .............. ..................

Iron,tricarbonyl-[n-(phenyl-2-

pyridinylmethylene)-benze

namide-N,N .......................... .................... .............. ................ .............. ✔ .................. .................. .............. ..................

Isophorone ............................... 78–59–1 ✔ ✔ .............. .............. .................. .................. .............. ..................

Isopropylbenzene (cumene) .... 98–82–8 .............. ✔ ✔ .............. .................. .................. ✔ ..................

Isopropyl methyl-phosphonic

acid ....................................... 1832–54–8 .............. ✔ .............. .............. .................. .................. .............. ..................

Maleic hydrazide ...................... 123–33–1 .............. ✔ .............. .............. .................. .................. .............. ..................

Merphos oxide ......................... 78–48–8 .............. ✔ .............. .............. .................. .................. .............. ..................

Methane, tertbutoxyisopropoxy- ................ .................... .............. ................ .............. ✔ .................. .................. .............. ..................

Methanol .................................. 67–56–1 .............. ................ ✔ .............. .................. .................. ✔ ..................

Methyl bromide ........................ 74–83–9 .............. ................ .............. .............. .................. .................. .............. ..................

Methyl isobutyl ketone (MIBK) 108–10–1 ✔ ................ .............. .............. .................. ✔ ✔ ..................

Methyl methacrylate ................. 80–62–6 .............. ................ .............. .............. .................. .................. ✔ ..................

Methylene bis

phenylisocyanate .................. 101–68–8 .............. ................ .............. .............. .................. .................. ✔ ..................
52206 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

TABLE 3.—INITIAL LIST OF CHEMICAL CONTAMINANTS CONSIDERED DURING DEVELOPMENT OF THE DRAFT CCL—

Continued

Contaminant CAS No.

Contaminant lists considered

1991

DWPL

(1)

Health

advisories

(2)

IRIS

(3) PWS (4) CERCLA(5)

Stakeholder

summary

list (6)

TRI list

(7)

OPP ranking

(8)

Other fuel oxygenates (TAME,

DIPE, ETBE) ........................ na .............. ................ .............. .............. .................. ✔ .............. ..................

n-Butanol .................................. 71–36–3 .............. ................ ✔ .............. .................. .................. ✔ ..................

n-Hexane .................................. 110–54–3 .............. ✔ .............. .............. .................. .................. .............. ..................

Naphthalene ............................. 91–20–3 ✔ ✔ .............. .............. .................. ✔ ✔ ..................

nitro-Cyclopentane ................... .................... .............. ................ .............. ✔ .................. .................. ..............

Nitrocellulose ............................ 9004–70–0 .............. ✔ .............. .............. .................. .................. .............. ..................

Nitroglycerine ........................... 55–63–0 .............. ................ .............. .............. .................. .................. ✔ ..................

Nitroquanidine .......................... .................... .............. ✔ .............. .............. .................. .................. .............. ..................

o-Chlorotoluene ........................ 95–49–8 ✔ ✔ .............. .............. .................. .................. .............. ..................

Octatriene, 3,7-dimethyl-1,3,6- 13877–91–3 .............. ................ .............. ✔ .................. .................. .............. ..................

Organotins (tributyl, methyl tin,

etc.) ....................................... .................... .............. ................ .............. .............. .................. ✔ .............. ..................

P-Chlorotoluene ....................... 106–43–4 ✔ ✔ .............. .............. .................. .................. .............. ..................

Pentachloroethane ................... 76–01–7 .............. ✔ .............. .............. .................. .................. .............. ..................

Propylbenzene n- ..................... 103–65–1 .............. ✔ .............. .............. .................. .................. .............. ..................

Propylene glycol ....................... 57–55–6 .............. ................ .............. .............. .................. ✔ .............. ..................

Propylene oxide ....................... 75–56–9 .............. ................ .............. .............. .................. .................. ✔ ..................

Rhodamine WT ........................ .................... .............. ................ .............. .............. .................. ✔ .............. ..................

RDX (cyclo trimethylene

trinitramine) ........................... 121–82–4 .............. ✔ .............. .............. .................. .................. .............. ..................

Terbuthylazine .......................... 5915–41–3 .............. ................ .............. ✔ .................. .................. .............. ..................

Tetrahydrofuran ........................ 109–99–9 ✔ ................ .............. .............. .................. ✔ .............. ..................

Tetranitromethane (TNM) ........ 509–14–8 .............. ✔ .............. .............. .................. .................. .............. ..................

Trichlorofluoromethane ............ 75–69–4 .............. ✔ .............. .............. .................. .................. .............. ..................

Triethylbenzene ........................ 25340–18–5 .............. ✔ .............. .............. .................. .................. .............. ..................

Trinitrotoluene (TNT) ................ 118–96–7 .............. ✔ .............. .............. .................. .................. .............. ..................

Vinyl acetate ............................ 108–05–4 .............. ................ .............. .............. .................. .................. ✔ ..................

1. 1991 Drinking water Priority List, but does not include disinfection by-products or crytosporidium for which regulations are being under the

M/DBP rules.

2. Health Advisories developed under EPA’s Health Advisory Program. Does not include contaminants regulated under the SDWA.

3. Contaminants from IRIS based on a risked-based screen developed by EPA.

4. Contaminants identified in public water systems samples as non-targets.

5. First 50 contaminants of the 1995 ATSDR Ranked CERCLA priority chemicals list.

6. Stakeholder Summary List consists of specific contaminants proposed as candidates by participants of EPA’s December 2–3, 1997 Stakeholder Meeting on the Contaminant Identification Method.

7. The TRI List was derived from chemicals with significant health effects as found in IRIS.

8. The OPP Ranking is a ranking of pesticides from highest to lowest potential to leach to ground water.

9. Stakeholders requested that the Agency address tirazines as a class of contaminants including their degradates, as opposed to addressing

them as individual contaminants.

a. 1991 Drinking Water Priority List.

The SDWA, as amended in 1986,

required EPA to publish a triennial list

of priority contaminants, the DWPL,

which may require regulation. The first

list containing 53 contaminants/

contaminant group was published on

January 2, 1988 (53 FR 1892). Since

none of the contaminants had been

selected for regulation, EPA revised and

updated the 1988 list three years later.

The revised and updated list, published

on January 14, 1991 (56 FR 1470),

contained 50 substances carried over

from the 1988 list and 27 new

substances, bringing the total number of

contaminants/contaminant groups to 77,

including one microorganism.

In consideration of the statutory

requirements and the time frame for

rulemaking in the SDWA at the time,

EPA used the following criteria to select

contaminants for the DWPL: (1)

occurrence or the potential occurrence

of the substance in public water

systems; (2) documented or suspected

adverse health effects; and (3) the

availability of sufficient information on

the substance so that a regulation could

be developed within the statutory time

frame. The contaminants were selected

from the following groups: disinfectants

and their byproducts, the first group of

100 contaminants on the 1987 CERCLA

priority list of hazardous substances (52

FR 12866), design analytes of the EPA

National Pesticide Survey conducted

between 1987–1990, pesticides with

high potential for leaching in

groundwater, substances recommended

by the States and EPA regions,

unregulated contaminants monitored

under Section 1445 of the SDWA, and

certain substances reported frequently

and at high concentrations in drinking

water. The selection of contaminants

was made with the assistance of the

DWPL workgroup which consisted of

representatives from various programs

within the Agency, the National

Toxicology Program, the U.S. Geological

Survey, and the Agency for Toxic

Substances and Disease Registry.

For development of the draft CCL, the

Agency selected contaminants from the

1991 DWPL that were not specifically

addressed by other regulations under

development. Thus, all contaminants

specifically addressed by the

disinfectants and disinfection

byproducts regulation were eliminated

from consideration.

b. Health advisories. The Health

Advisories (HAs) are prepared for

contaminants that have the potential to

cause adverse human health effects and
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52207

which are known or anticipated to occur

in drinking water, but for which no

national regulations currently exist.

Each HA contains information on the

nature of the adverse health effects of

the contaminant and the concentrations

that would not be anticipated to cause

an adverse effect following various

periods of exposure. HAs also

summarize available data on

occurrence, pharmacokinetics,

environmental fate, health effects,

available analytical methods, and

treatment techniques for the

contaminant. HA concentration levels

include a margin of safety to protect

sensitive members of the population

(e.g., children, the elderly, pregnant

women).

The Office of Water Health Advisory

Program was initiated to provide

information and guidance to individuals

and agencies concerned with potential

risk from drinking water contaminants.

HAs are used only for guidance and are

not legally enforceable, and are subject

to change as new information becomes

available. For purposes of developing

the draft CCL, all contaminants with

HAs, or HAs under development, were

considered.

c. Integrated Risk Information System.

The Integrated Risk Information System

(IRIS) is an EPA on-line database

containing health risk and EPA

regulatory information. IRIS lists

chemicals of interest or concern for

which the Agency has reached

consensus regarding adverse health

effects. When available, a reference dose

(RfD) for non-cancer health effect

resulting from oral exposure is reported

with information about how the RfD

was derived and any uncertainty

regarding the source studies. An RfD is

an estimate of a daily exposure to the

human population that is likely to be

without appreciable risk of adverse

effect over a lifetime of exposure. For

carcinogens, a carcinogenic assessment,

or cancer potency factor, is reported for

both oral and inhalation exposure. The

cancer potency factor is the estimated

risk to the human population of cancer

effects over a lifetime of exposure.

In 1992, in anticipation of the next

DWPL, the Agency developed a list of

chemicals based on a risk-based screen

of chemicals in IRIS. There were

approximately 600 chemicals in the IRIS

database in 1992, and 312 were selected

for further screening. The 312 were

chosen because they had defined

toxicity via the oral route of exposure

and did not have NPDWRs. The 312

chemicals were screened using the

following categories: (1) using Storage

and Retrieval (STORET) data, chemicals

were identified with concentration in

water that exceeded the drinking water

equivalent level (DWEL) which was

derived from the reference dose or

cancer potency; (2) chemicals were

identified that were produced in

quantities exceeding one billion pounds

per year; (3) pesticides were identified

with use exceeding 1000 tons per year;

and (4) chemicals were identified that

were reported in the Toxic Release

Inventory (TRI) database as discharged

to surface water in excess of 100 tons

per year. Sixteen chemicals met the

STORET criteria; nine, the production

criteria; 31, the pesticides criteria; and

6, the TRI criteria. A total of 48

individual chemicals were identified,

and some were identified by more than

one screen. All 48 contaminants were

included on the initial list for

consideration.

d. Non-Target Analytes in Public

Water Supply Samples. In anticipation

of the 1994 DWPL, the Agency

consulted with analytical laboratories

that routinely analyze samples for

public water systems to determine what

contaminants were occurring that were

not currently regulated. A list of

contaminants tentatively identified in

1991 from drinking water samples

collected for compliance monitoring

was developed. These contaminants,

also referred to as non-targets analytes,

are compounds identified by the spikes

found on the chromatograph. The

concentrations for these compounds

were not measured. These non-target

analytes represent the monitoring

experience of several water systems

with operations in various states. The

contaminants included on the initial list

for consideration are a subset of 23

contaminants chosen from the larger list

of non-targets analytes. The 23

contaminants were chosen because they

were considered to be related to

possible anthropogenic sources.

e. CERCLA Priority List. In developing

the CCL, the SDWA requires EPA to

consider substances referred to in

section 101(14) of the CERCLA.

CERCLA requires the Agency for Toxic

Substances and Disease Registry

(ATSDR) to prepare a list in the order

of priority of hazardous substances

which are most commonly found at

facilities on the CERCLA National

Priority List (NPL).

In 1995, ATSDR developed a list of

275 hazardous substances ranked by the

order of priority. (ATSDR, 1996) To

develop this list, ATSDR considered 750

of 2800 substances present at NPL sites

and ranked them based on the following

three criteria, which were combined to

result in a total score. These criteria

were: (1) Frequency of occurrence at

NPL sites, (2) toxicity, and (3) potential

for human exposure. The number of

NPL sites at which a substance was

identified in any medium was used to

indicate the frequency of occurrence.

EPA’s Reportable Quantity (RQ) was

used to assess the toxicity of candidate

substance. If a RQ was not available, the

RQ methodology was applied to

candidate substances to establish a

Toxicity/Environmental Score. The

human exposure component was based

on two parts: the concentration of the

substance in the environmental media

and the exposure status of population.

EPA included the top 50 substances

from the 1995 CERCLA prioritized list

of 275 substances for consideration for

the draft CCL.

f. Stakeholder responses. In December

1996, the EPA convened its first

stakeholder meeting on the contaminant

identification process. At that meeting,

EPA requested input on what

contaminants to include on its first CCL.

At the December meeting, and

following, participants have provided

input to the Agency on contaminants for

inclusion on, or exclusion from, the

CCL. Some stakeholders provided

information on health effects or

occurrence, or both, while others listed

contaminants. All contaminants

suggested by stakeholders were

included for initial consideration except

those which already had NPDWRs, or

which were included under other

regulatory activity mentioned in section

VIII of this notice.

g. Toxic Release Inventory. Another

source of available information which

could serve as a predictor of anticipated

occurrence in drinking water, is the TRI.

This data base, established under the

Emergency Planning and Community

Right-to-Know Act of 1986, contains

information from manufacturing

facilities in the United States regarding

transfers and releases of toxic and

hazardous materials to air, ground and

water. The most recent report analyzed

data gathered for calendar year 1994

from 22 chemical categories and

included 343 separate chemicals from

23,000 facilities which met certain

thresholds requiring submission of data.

(U.S. EPA, 1997c).

In order to assess the potential for a

chemical to be a contaminant in public

water systems, EPA conducted an

analysis of the release and emissions

data. Each of the four categories of

emissions or discharges were assigned a

threshold value above which the

contaminant was deemed to fit within

the criteria of the SDWA, as a

contaminant anticipated to occur in

public water systems. The threshold did

not attempt to attribute differences in

reactivity, solubility, mobility or
52208 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

toxicity of the pollutants at this stage of

the contaminant evaluation process, but

involved simply determining a gross

anticipation factor. If a contaminant was

released via an on-site discharge to the

environment, EPA judged that it was

reasonable to anticipate it as a

contaminant in public water systems to

varying degrees, depending upon the

media receiving the discharge.

The overall analysis of the above TRI

criteria resulted in 58 chemicals from

the various discharges meeting the

criteria. Where a release was close to the

threshold, it was included in the tally.

Several chemicals met the criteria but

were excluded because there is an

existing standard (e.g., hydrofluoric

acid—fluoride is regulated) or a

standard under consideration (sulfuric

acid—there is regulatory activity

currently underway regarding sulfate).

Other contaminants such as ammonia,

hydrochloric acid, or methanol were not

believed to represent a significant threat

to drinking water due to limited

persistence, leaving 51 contaminants. Of

the 51 contaminants, 49 met the criteria

for air release, 21 from stack emissions,

38 for fugitive emissions, 11 via

underground injection, 13 from land

release, and 30 for surface water

releases. All 51 were included for initial

consideration in Table 3.

h. Pesticides identified by Office of

Pesticide Programs. In developing the

CCL, the SDWA requires EPA the

consider substances referred to in the

FIFRA. During the development of the

draft CCL, the Agency’s Office of

Ground Water and Drinking Water

sought assistance from the Office of

Pesticide Programs (OPP) in

determining what pesticides should be

priorities for the drinking water

program. In response to the request,

OPP provided recommendations for a

number of pesticides. (U.S. EPA, 1997b)

The list of pesticides, based on physicalchemical properties, occurrence and

extent of use, was ranked using the

Ground Water (GW) Risk score, a

calculated potential to leach to ground

water. Pesticides with a GW Risk of 2.0

or greater were included for initial

consideration in developing the CCL

(see Table 3).

However, later during the data

evaluation and screening phase of the

draft CCL development, the decision

was made to defer some of the

pesticides identified by the OPP GW

Risk of 2.0 or greater. The pesticides in

Table 4 include those where the GW

Risk value of 2.0 or greater was the only

factor for inclusion on the CCL. The

decision was made, that for these cases,

inclusion on the CCL would be deferred

pending further evaluation of the

potential of these pesticides to occur at

levels of health concern. Many new

pesticides for which no other data exists

are included in Table 4.

Table 4. Pesticides Deferred

Asulam

bensulfuron methyl

bentazon

bromacil

Cadre

chlorimuron ethyl

chlorsulfuron

Diazinon—oxypyrimidine

Dicamba

Ethylenethiourea (ETU)

Fenamiphos

Fluometuron

Halofenozide

Halosulfuron

Hexazinone

Imazamethabenz

Imazapyr

Imazaquin

Imazethapyr

MCPA (Methoxone)

Methsulfuron methyl

Nicosulfuron

Norflurazon

Primisulfuron methyl

Prometryn

Propazine

Prosulfuron

Pyrithiobac-Na

Rimsulfuron

Sulfentrazone

Sulfometuron methyl

Tebufenozide

Terbufos sulfone

Thiazopyr

Triasulfuron

The Agency is working to develop a

tool to estimate concentrations in

ground and surface waters based on

physical-chemical properties and

pesticide use volumes, and then

compare the estimated concentrations

with health advisory levels or calculated

health levels based on reference doses

or cancer potency. The model is

expected to be completed and available

for use at the end of 1997, and at that

time the Agency will reevaluate the

inclusion for the additional pesticides

on Table 4 on the CCL.

On August 4, 1997, EPA announced

its schedule for reassessing tolerances

for pesticide residues on raw and

processed foods (62 FR 42020).

Publication of this schedule was

pursuant to the requirements, as

established by the Food Quality

Protection Act of 1996 (FQPA). Under

this new law, EPA is required to

reassess all existing tolerances and

exemptions from tolerances for both

active and inert ingredients. EPA is

directed to give priority review to

pesticides that appear to present risk

concerns based on current data. Many of

the pesticides included in today’s notice

are included among the first group of

reassessments.

In reassessing tolerances, EPA must

consider the aggregate exposure to the

pesticide, including drinking water;

cumulative effects from other pesticides

with a common mode of toxicity;

whether there is an increased

susceptibility from exposure to the

pesticide to infants and children; and

whether the pesticide produces an effect

in humans similar to an effect produced

by a naturally occurring estrogen or

other endocrine effects.

i. Safe Drinking Water Hotline. The

Hotline provides information about

EPA’s drinking water regulations and

other related drinking water and ground

water topics to the public, the regulated

community, and State and local

officials. The Hotline assists callers with

questions on the regulations and

programs developed in response to the

Safe Drinking Water Act, and inquiries

about the levels and health effects of

specific contaminants found in or

suspected to be in drinking water from

public water systems and private wells,

and handles requests for drinking water

publications (fact sheets, pamphlets,

health advisories, etc.). The Safe

Drinking Water Hotline receives

hundreds of calls each week, and a large

percentage of the calls come from

private citizens, consultants, educators,

researchers, and health care

professionals from across the country.

The Hotline provided a list of

contaminants that were not currently

regulated or proposed for regulation for

which callers had expressed concern or

interest (see Table 5).

Table 5. Contaminants Identified by the

Safe Drinking Water Hotline

Calcium

Phosphates

1,1,1-dichloroethane

Gasoline

Perchlorate

Total Petroleum Hydrocarbons

The Hotline did not ascertain if the

calls were due to a general question or

inquiry, or if they were related to a

contamination incident. At the April 3–

4, 1997 Working Group meeting, the

decision was made not to include the

Hotline list for initial consideration, and

that a list from the Hotline would only

be useful if it captured concerns or

reports of contamination.

The Agency will attempt to capture

Hotline inquiries concerning

contamination incidents for future CCL

development. Perchlorate, a

contaminant discussed later in this

notice, probably should have been
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52209

included for initial consideration. The

fact that perchlorate was on the Hotline

list, and no other, may indicate that

such a list from the Hotline could be

useful if the nature of the inquiry can be

recorded.

j. Endocrine disruptors. A list of

contaminants was developed which

included those suspected of having

adverse effects on endocrine function

(see Table 6). For several years, the

Agency has been concerned that

chemicals may be disrupting the

endocrine (i.e., hormonal) systems of

humans and wildlife. It has also been

hypothesized that endocrine disruption

might result in cancer, harm to male and

female reproductive systems, thyroid

damage, or other adverse consequences.

In February 1997, EPA issued an

assessment and analysis of this concern

(U.S. EPA, 1997a). The report represents

an interim assessment pending a more

extensive review expected to be issued

by the National Academy of Sciences

(NAS) later this year.

Table 6. Contaminants Identified as

Suspected of Endocrine Disruption

Amitrole

Benomyl

Dicofol (Kelthane)

Esfenvalerate

Ethylparathion

Fenvalerate

Kepone

Mancozeb

Metiram

Mirex

Nitrofen

Oxychlordane

Parathion

Permethrin

Synthetic pyrethroids

Transnonachlor

Tributyltin oxide

Vinclozolin

Zineb

Ziram

Octachlorostyrene

PBBs

Penta- to nonyl-phenols

In brief, the report found that while

effects have been found in laboratory

animal studies, a causal relationship

between exposure to a specific

environmental agent and an adverse

health effect in humans operating via

endocrine disruption has not been

established, with a few exceptions. The

exceptions include incidents of

chemical exposure in the workplace and

exposure to the drug DES. Further

research is needed before such effects

can be demonstrated.

Under the SDWA, as amended, the

Agency is also required to establish a

program to screen endocrine disrupting

contaminants. Additional authority to

assess endocrine disruptors is also

provided through the recently enacted

FQPA. EPA’s Office of Prevention,

Pesticides, and Toxic Substances

(OPPTS) has the Agency lead on

endocrine disruptor screening and

testing issues. OPPTS is actively

engaged in research and regulatory

initiatives to respond to the growing

scientific and public concern over

endocrine disruptors.

The Endocrine Disruptor Screening

and Testing Advisory Committee

(EDSTAC) has been established to

provide advice and counsel to the

agency in implementing a screening and

testing strategy required under the

FQPA and SDWA. EDSTAC is

composed of a balanced representation

from industry, government,

environmental and public health

groups, labor, academia, and other

interested stakeholders. During its

deliberations, the Committee will

consider human health, ecological,

estrogenic, androgenic, anti-estrogenic,

anti-androgenic, and thyroid effects of

pesticides, industrial chemicals, and

important mixtures. EDSTAC will

complete its recommendations for a

screening and testing strategy by March,

1998. The recommendations will be

peer reviewed jointly by the SAB and

the FIFRA Scientific Advisory Panel.

EPA is also involved in concurrent

effort to coordinate activities with the

European Union, the Organization of

Economic and Community

Development, and the United Nations

Environmental Program concerning

global research programs, and

international harmonization of

endocrine disruptor screening and

testing methods for chemicals and

pesticides.

As a result, pending completion of the

EDSTAC’s recommendations and the

additional review of endocrine

disruptors by the NAS, EPA has not

included contaminants for initial

consideration for the draft CCL based

solely on the possibility of endocrine

disruption (although several

contaminants implicated as endocrine

disruptors were considered for other

reasons). The Agency will continue to

follow this issue closely and reconsider

this category of potential contaminants

in the development of future CCLs.

2. Development and Application of the

Criteria

Criteria were developed by the

NDWAC Working Group for use in

screening and evaluating chemical

contaminants for the draft CCL, with the

exception of aldicarbs, nickel, and

sulfate which are discussed in section

III.C.3. The general premises of the

criteria were: (1) The contaminants

included for initial consideration be

those on EPA’s initial list, without

NPDWRs, and (2) that occurrence, or

anticipated occurrence, of the

contaminant be evaluated first, before

evaluating its health effects information.

The criteria, presented below, were used

to screen and evaluate chemical

contaminants for the purpose of

developing today’s draft CCL. Data used

to evaluate and screen contaminants

were obtained from STORET, the

Hazardous Substances Database (HSDB),

IRIS, published literature, and various

EPA reports and documents. The data

used in the evaluation and screening are

included in the docket for today’s

notice.

These criteria, as well as the

conceptual approach to the

Contaminant Identification Method

(CIM) presented in the December 2–3,

1996 Stakeholders meeting, will serve as

the basis for developing a more robust

contaminant identification method for

future CCL development. The search

results on each element of the criteria

for contaminants considered during the

development of the CCL can be found

by using the Occurrence Table, the

Health Table, and the Comments Table

included in the docket for today’s

notice.

a. Criteria for occurrence. For the

occurrence portion of the criteria, an

affirmative response to any of the

following elements would result in

moving to the health portion of the

criteria for further consideration. If all of

the occurrence elements had a negative

response, the contaminant was

eliminated from further consideration.

The two main elements to the

occurrence portion of the criteria were

as follows: (1) Was the contaminant

looked for and found in drinking water,

or in a major drinking water source, or

in ambient water at levels that would

trigger concern about human health? (2)

if the contaminant was not looked for,

is it likely to be found in water based

on surrogates for occurrence?

To judge whether a contaminant was

looked for and found in drinking water,

according to the criteria, it would need

to be included in a major survey which

was defined as one which included a

population of 100,000 or more, 2 or

more states, or 10 or more small public

water systems, or a data set such as

EPA’s Unregulated Contaminants

Database. To judge whether a

contaminant was looked for and found

in a major drinking water source, or in

ambient water, any source of occurrence

data could be used. A source of drinking

water was considered to be major if it

supplied a population of 100,000 or
52210 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

more, or 2 or more states. Levels that

would trigger concern about human

health were defined as concentrations in

samples within an order of magnitude of

the level that is likely to cause health

effects, or at least 1⁄2 of samples at 50%

of level that is likely to cause health

effects. Contaminants were considered

to have met the criteria if the data

available indicated occurrence at a

population of 100,000 or more; or in 2

or more states; or in 10 or more small

public water systems at levels that

would trigger concern about human

health.

If the contaminant was not looked for

using the data available, it was

evaluated to determine if it was likely

to be found in water based on surrogates

for occurrence. The elements considered

as surrogates for occurrence included:

TRI releases, or production volumes,

coupled with physical-chemical

properties, or the OPP GW Risk value.

In order for a contaminant to meet this

criterion as likely to be found in water

using TRI, the release to surface water

was in excess of 400,000 pounds per

year, and the physical-chemical

properties indicated persistence &

mobility of the contaminant. The

quantity of 400,000 pound per year was

based on the top 15 TRI chemicals with

the largest discharges to surface water as

reported in 1995. In order for a

contaminant to meet this criterion as

likely to be found in water using

production, the volume was in excess of

10 billion pounds per year, and

physical-chemical properties indicated

persistence and mobility.

For a contaminant to meet this criteria

as likely to be found in water using OPP

GW Risk, the value was 2.0 or greater.

However, late during the data

evaluation and screening phase of the

CCL development, the decision was

made to defer contaminants identified

under this element until a more indepth analysis could be performed that

would include risk to both surface and

ground water, and a component to

address health.

b. Criteria for health. For the health

portion of the criteria, an affirmative

response to any of the following

elements resulted in including the

contaminant on the first CCL, if it also

met the occurrence criteria. A negative

response to every question resulted in

the contaminant being eliminated from

consideration for the CCL. The health

portion of the criteria had one major

component; was there evidence, or

suspicion, that the contaminant causes

adverse human health effects? This

portion of the criteria was met if a

contaminant had one or more of the

following elements: (1) Listed by

California Proposition 65, (2) an EPA

Health Advisory, (3) a likely (based on

animal data) or known (based on human

data) carcinogen by EPA or International

Agency for Research on Cancer (IARC),

(4) more than one human

epidemiological study (indicating

adverse effects), (5) an oral value in

IRIS, (6) regulated in drinking water by

another industrial country, (7) a member

of a chemical family of known toxicity,

or (8) structural activity relationship

indicating toxicity.

As the contaminants were being

screened and evaluated, the factors for

health which proved to be the most

useful were those that provided a health

level of concern as a concentration that

could be compared to the levels of

occurrence found in water, such as an

EPA Health Advisory, an oral value in

IRIS, or a regulatory level from another

industrial country. Being listed by

California Proposition 65, or a member

of a chemical family of known toxicity

had limited utility in determining

which contaminants to include on the

CCL.

3. Additional Specific Contaminants

Included

Aldicarbs, nickel, and sulfate are also

on the draft CCL. The SDWA, as

amended, did not specifically mention

aldicarbs and nickel, but since the

Agency has existing obligations for

completing regulatory action on these

contaminants pursuant to the SDWA, as

amended 1986, it was thought to be

prudent to include them on the CCL to

make clear the intention to address

these responsibilities. Sulfate is

included on the CCL, since the Agency

must make a determination to regulate

or not by August 2001, along with at

least four more contaminants. The

following sections provide the rationale

for the inclusion of aldicarbs, nickel,

and sulfate on the draft CCL.

a. Aldicarb, aldicarb sulfoxide, and

aldicarb sulfone. EPA promulgated a

final NPDWR for aldicarb, aldicarb

sulfoxide and aldicarb sulfone on July 1,

1991 (56 FR 30266). EPA set the

maximum contaminant level goal

(MCLG) at 0.001 mg/l and maximum

contaminant levels (MCLs) of 0.003 mg/

l for aldicarb, 0.004 mg/l for aldicarb

sulfoxide, and 0.002 mg/l for aldicarb

sulfone. In response to an

administrative petition from the

manufacturer Rhone-Poulenc, the

Agency issued an administrative stay of

the effective date of the MCLs, i.e., the

MCLs never became effective, but

monitoring is required. Rhone-Poulenc

also filed a petition for judicial review,

and the court stayed its proceedings

while EPA proceeded administratively,

but required quarterly reports. On

agreement of the parties, the judicial

proceedings have been dismissed. An

updated health advisory was issued in

1995 incorporating data from a human

study conducted in 1992 by Rhone

Poulenc. The aldicarbs were not subject

to the criteria used to identify other

chemical contaminants and are being

included on the CCL to signify the

Agency’s intention to complete the

regulatory activity for these

contaminants. At this point, however,

the time frame of completing action

relative to aldicarbs has not been

determined.

b. Nickel. NPDWRs for nickel

including an MCLG and an MCL of 0.1

mg/l were proposed on July 25, 1990 (55

FR 30370) and finalized on July 17,

1992 (57 FR 31776). In September, 1992,

the Nickel Development Institute and

other industry parties filed a petition for

review in the U.S. Court of Appeals for

the D.C. Circuit challenging the MCLG

and MCL for nickel. The petitioners

raised objections over EPA’s

methodology for determining the MCLG

for nickel. Specifically, they raised

questions concerning the derivation of

the relative source contribution factor

and the need for a 3-fold uncertainty

factor that EPA applied due to the lack

of adequate data on the effects of nickel

ingestion on reproductive systems.

Because the MCL for nickel was based

directly on the MCLG, the petitioners

also challenged the nickel MCL.

EPA and the petitioners entered into

discussions in an attempt to settle this

litigation but could not agree on the

merits of the petitioners’ challenges.

Nevertheless, EPA agreed that it did not

fully address in the public record the

petitioner’s comments on the proposed

methodology for deriving the MCLG for

nickel, and agreed to take a remand of

the MCLG and MCL for nickel.

Accordingly, on February 9, 1995, EPA

and the nickel industry petitioners filed

a joint motion for a voluntary remand of

the nickel MCL and MCLG. By orders of

February 23, 1995 and March 6, 1995,

the court granted this motion and

vacated and remanded the nickel MCLG

and MCL (and dismissed the lawsuit).

No other aspects of the NPDWRs for

nickel were vacated, including

monitoring requirements and

identification of best available

technologies for nickel. A notice of this

action was published in June 1995 (60

FR 33929).

To provide guidance for the period

prior to new regulations for nickel, the

EPA updated and issued a health

advisory for nickel. Nickel was not

subject to the criteria used to identify

other chemical contaminants and is
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52211

being included on the CCL to signify the

Agency’s intention to complete

regulatory action for this contaminant.

The time frame of completing action on

nickel has not yet been determined.

c. Sulfate. As noted above, by August,

2001 the Agency must decide whether

or not to regulate sulfate. The date for

making a determination about sulfate

coincides with the date by when

determinations must be made for 5 or

more contaminants from the first CCL.

Sulfate was not subject to the criteria

used to identify other contaminants;

however, it has been included, given

these special circumstances.

IV. Contaminants on the CCL Which

Are of Specific Interest

A number of contaminants included

on the draft CCL may be of particular

interest. The following sections attempt

to provide additional information for a

few of the contaminants that seem to be

of most interest. Data obtained and

evaluated for developing the draft CCL

and referred to in the following

discussion can be found in the docket

for this notice.

A. Aluminum

There is intense interest from some

for development of drinking water

regulations for aluminum. Aluminum

currently has a secondary MCL of 50 to

200 ‘‘μg/l based on organoleptic

properties. There have been a few

epidemiological studies in Canada that

emphasize the need to determine if

regulations for this contaminant should

be developed based on health effects. At

present, based on the work in Canada,

it appears that the most sensitive

population is the elderly. To determine

if aluminum is of health concern to the

elderly and to other possible sensitive

groups like children, the EPA

collaborated with Health Canada on a

workshop on aluminum held September

3 and 4, 1997. This workshop was

planned to help define the need for

chronic animal studies and the use of

appropriate animal models to better

characterize the risk of this contaminant

in drinking water. The Agency will

continue to work to determine if

aluminum is of health concern, and the

appropriate action to address this

concern.

B. MTBE

MTBE (methyl-t-butyl ether) is a fuel

additive used in many locations

throughout the United States to reduce

carbon monoxide and ozone forming

precursors associated with the

combustion of fossil fuels. There is

evidence of contamination of drinking

water; however the extent of

contamination of drinking water

supplies on a national scale is unclear

at this time (IAOF, 1997). The Agency

is in the process of revising the HA for

MTBE that will incorporate updated

health effects information, and has

completed a research strategy to guide

efforts at improving the understanding

of the occurrence and health effects of

MTBE (U.S. EPA, 1997e). As more PWSs

across the country voluntarily monitor

for MTBE, and if it is found at levels of

concern nationally, the Agency does

have the capacity to make a

determination to develop regulations to

monitor and/or control MTBE prior to

the 2001, SDWA deadline for selecting

at least 5 contaminants for

determination.

C. Organotins

Organotins represent a class of

contaminants which include, methyl

tin, tributyltin, and others. The

organotins of concern are those that

result from use in heat stabilizing PVC

piping for the in-home distribution of

water. There are a few cases of

tributyltin contamination of drinking

water in the U.S. (Sadiki, 1996). It has

been reported that the Canadian

government is concerned about

organotin contamination and has

planned a national survey of drinking

water in Canada to assess the danger to

human health.

The concentrations of concern for

human health are not known at this

time, however tributly tin and other

organotins are known to be toxic to

aquatic life. On August 7, 1997, the

Agency published a notice of ambient

water quality criteria document for

tributyltin (TBT) and a request for

comments (62 FR 42554). Ambient

water quality criteria are for the

protection of aquatic organisms and

guidance to States and others, and may

form the basis for enforceable State

water quality standards developed

pursuant to Section 304(a)(1) of the

Clean Water Act.

D. Rhodamine WT

Rhodamine WT is a fluorescent dye

widely used as a tracer to measure

ground water flow. Rhodamine WT has

been certified by the National Sanitation

Foundation for use in tracing water

under the conditions that it not exceed

concentrations in drinking water of 0.1

μg/l and that exposure be infrequent.

Rhodamine WT was detected in ground

water above the 0.1 μg/l value; however

the conditions under which the

detections occurred are unclear.

Rhodamine WT appears to be a

contaminant that the Agency may need

to observe more closely in terms of its

health effects, and possible occurrence

in drinking water.

E. Sodium

At present, the Agency has no

NPDWR or HA value for sodium. All

that is currently available is a guidance

DWEL of 20 mg/l. DWELs are

unenforceable guidance levels

describing a lifetime exposure

concentration of a contaminant that is

considered protective of adverse noncancer health effects, and it also

assumes that all of the exposure to a

contaminant is from a drinking water

source. In addition, EPA has a nonenforceable criterion for dissolved

solids and salinity for ambient waters of

250 mg/l.

The DWEL is based on a 1965

American Heart Association

recommendation of a 20 mg/l sodium

level to protect genetically susceptible

people on low sodium diets, assuming

a total dietary intake of 500 mg/day.

Naturally occurring sodium in food with

no salt added averages about 440 mg/

day. The additional 60 mg that would

increase the intake to the typical level

for a restricted diet of 500 mg/day must

take into account all other non-food

sources, such as drugs, water, etc. A

concentration in drinking water of up to

20 mg/l of sodium is compatible with

this diet.

Since a significant percentage of the

U.S. population is attempting to reduce

their sodium intake, the Agency

believes that sodium levels in drinking

water could be an important issue. This

is particularly true for locations where

many of the residents using the water

may be susceptible to adverse health

effects from exposure to this

contaminant. The Agency believes that

all consumers are able to use water for

drinking if the sodium concentration is

maintained at or below 20 mg/l, but

nearly half of the nation’s water

supplies have natural or added sodium

above these levels.

The inclusion of sodium on the CCL

is controversial, but it is expected that

guidance will be developed for those

who need it, and that including it on the

CCL will be a mechanism to develop an

Agency position on the issue of sodium

in drinking water.

F. Zinc

Zinc is used as a dietary supplement,

main ingredient in lozenges, and

corrosion inhibitor. There is intense

interest over including zinc on the CCL,

but there are also indications of health

effects associated with increased levels

of zinc consumption.

The Agency is aware that zinc is an

essential element for which the Food
52212 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

and Nutrition Board of the National

Research Council has established a

Recommended Dietary Allowance

(RDA). Zinc can also cause adverse

health effects at high doses and the zinc

RfD (0.3 mg/kg/day) is higher than the

RDA for adult men and women. While

deriving RfDs, EPA must also keep in

mind the fact that excess exposure to an

essential trace element, such as zinc,

can also cause adverse health effects.

The present RfD for zinc represents a

balance between the essential

requirement for zinc and the toxic

effects of too much zinc; however, the

Agency is currently working on revising

the risk assessment procedures for

essential elements. The World Health

Organization (WHO) is also in the

process of developing a document on

the risk assessment of essential trace

elements, and EPA will consider the

WHO document when it is available.

G. 2,6-di-tert-butyl-p-benzoquinone

(DTBB)

DTBB is a contaminant that appears to

be associated with sewage

contamination of ground water. A

ground water study concluded that

DTBB was a good indicator of such

contamination because, among other

reasons, it does not biodegrade readily

(Barber, 1988). DTBB was determined

not to meet the criteria for the draft CCL

per se, but was included nevertheless,

because of the recalcitrant nature of the

contaminant, its association with

sewage contamination, its potential

health impacts, and its potential to serve

as an indicator of other contamination.

H. Contaminants to be Considered as

Groups

Stakeholders, through the regulatory

reassessment process and the

development of this draft CCL, have

requested that the Agency, address

triazine pesticides as a group which

includes all parent and degradates

compounds as opposed to each triazine

as an individual contaminant. The

triazine pesticides include; cyanazine,

propazine, etc., and atrazine and

simazine (which are both currently

regulated), and are often substituted for

one another for similar agricultural use.

The USEPA regulated atrazine in 1991

and simazine in 1992. Cyanazine and

atrazine-desethyl, a degradation product

of triazines, were identified for the draft

CCL using the criteria discussed earlier,

and because of the common effect of

triazine pesticides and degradates,

Office of Ground Water and Drinking

Water (OGWDW) and OPP are

coordinating to have atrazine and

simazine, and possibly other triazines, if

warranted, addressed as a group. A

triazine special review was initiated by

OPP which will culminate in a

proposed decision on the labeling and

agricultural use triazine. The proposal is

expected during the summer of 1998.

The triazines are also included in the

Priority Group 1 of pesticide tolerances

that will be examined first under the

FQPA tolerance reassessment (62 FR

42020).

The Agency is concerned about

triazines in water and the exposure of

sensitive populations, including

children, and OGWDW will work

closely with OPP to characterize the risk

of triazines in food and water. EPA has

been studying the mechanism of

carcinogenicity of this group of

analogues along with their degradation

products, and will continue to study

these chemicals as a group to

characterize their risk in drinking water.

The Agency may ultimately develop

regulations for the mixtures of triazines

either through the revision of existing

regulations or the development of new

ones. The same may occur for other

families of pesticides, such as the

acetanilide pesticides, which include

acetochlor, metolachor, alachlor (which

is currently regulated), given their

common effects and agricultural uses.

I. Contaminants for Which Unregulated

Contaminant Data Are or Will Be

Available

Unregulated contaminant monitoring

data which have been collected a

number of contaminants during 1988–

1991, and additional monitoring data

collected during 1993–1995 (see Table

7). These monitoring data can serve in

evaluating whether these contaminants

should be included on the CCL. The

data collected during 1988–1991 have

been preliminarily evaluated by the

Agency; however, further analysis is

necessary to determine if a contaminant

in fact meets the criteria used to develop

the draft CCL. The data collected during

1993–1995, are not yet available;

however, during the comment period,

and prior to publishing the CCL by

February 1998, the Agency will attempt

to obtain and evaluate this data to

determine if the contaminant should

remain on the CCL. Contaminants that

do not meet the criteria as presented in

today’s notice, or as modified

subsequent to the comment period of

the notice, will not be included on the

final CCL to be published by February

1998.

Table 7. Contaminants with Unregulated

Contaminant Monitoring Data

1,3-dichloro-benzene

1,2,4-trimethyl-benzene

1,3-dichloropropene

1,3-dichloro-propane

1,1,2,2-tetrachloro-ethane

1,1-di-chloro-ethane

1,1-dichloro-propene

1,2,3-trichloro-propane

2,2-dichloro-propane

bromobenzene

bromomethane

carbaryl

o-chorotoluene

p-chlorotoluene

cumene

cymene

dichloro-difluoromethane

hexachlorobutadiene

metolachlor

metribuzan

naphthalene

n-propylbenzene

trichlorofluoro-methane

V. Request for Comment

The purpose of today’s notice is to

present the draft CCL and seek comment

on various aspects of its development.

The Agency requests comment on the

approach used to develop the CCL, and

on the contaminants included. The

Agency also requests comment on the

data and research needs categories the

contaminants have been divided into, in

Table 8. Any data supporting comments

or that can be used by the Agency in

developing the final CCL are also

requested. In addition to comments on

contaminants considered for the draft

CCL, the Agency seeks comment on the

inclusion of perchlorate on the final

CCL. The following sections provide

more detail on the data and research

needs and the issue of perchlorate.

A. Data and Research Needs

The microbiological contaminants

included on the CCL all have research

needs of one sort or another in the area

of analytical methods. The meeting

summary of the Workshop on

Microbiology and Public Health, held

May 20–21, 1997, provided more detail

of the research needed for

microorganisms.

For the chemical contaminants on the

draft CCL, Table 8 divides them into

categories to represent the data needs

for each contaminant. Sufficient data are

needed to conduct analyses on extent of

exposure and risk to populations via

drinking water in order to determine

appropriate Agency action

(development of health advisories, or

regulations, or no action) for a given

contaminant. If sufficient data are not

available, they must be obtained before

such an assessment can be made. The

data and information required will be

gathered by research or monitoring

programs, and are not likely to be

available for analyses to be completed
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52213

prior to 2001. Thus, the contaminants

for which sufficient data exists at the

time of publishing the CCL, are likely to

the those from which the

determinations will be made by 2001.

TABLE 8.—DATA NEEDS FOR CHEMICAL CONTAMINANTS INCLUDED ON THE DRAFT CCL

Sufficient health effects and occurrence data exist

Need additional health effects data, but not occurrence data

Need additional occurrence data,

but not health effects data

Need both health effects and occurrence data

1,1,2,2-tetrachloroethane; 79–34–5 Aluminum; 7429–90–5 ......... 1,2-diphenylhydrazine; 122–66–7 ... 2,6-di-tert-butyl-p-benzoquinone

(DTBB); 719–22–2

1,2,4-trimethylbenzene; 95–63–6 ..... Vanadium; 7440–62–2 ......... 2,4,6-trichlorophenol; 88–06–2 ........

1,1-dichloro-ethane; 75–34–3 2,2-dichloro-propane; 594–20–7 ..... DCPA mono-acid degradate; 887–

54–7

1,1-dichloro-propene; 563–58–6 2,4-dichlorophenol; 120–83–2 ......... DCPA di-acid degradate; 2136–79–

0

1,3-dichloropropane; 142–28–9 2,4-dinitrophenol; 51–28–5 .............. Organotins

1,3-Dichloropropene; 542–75–6 2,4-dinitrotoluene; 121–14–2

Boron; 7440–42–8 2,6-dinitrotoluene; 606–20–2

Bromobenzene; 108–86–1 2-methyl-phenol; 95–48–7

Cyanazine; 21725–46–2 Acetochlor; 34256–82–1

atrazine-desethyl (a triazine degradation product); 6190–65–4.Acetone 67–64–1

p-Cymene; 99–87–6 Alachlor ESA (an alachlor degradation product).

Hexachloro-butadiene; 87–68–3 Aldrin; 309–00–2

cumene; 98–82–8 DDE; 72–55–9

Manganese; 7439–96–5 Diazinon; 333–41–5

Methyl bromide; 74–83–9 Dieldrin; 60–57–1

Metolachlor; 51218–45–2 Dimethoate; 60–51–5

Metribuzin; 21087–64–9 Disulfoton, 298–04–4

Naphthalene; 91–20–3 Diuron; 330–54–1

Sodium; 7440–23–5 Fonofos; 944–22–9

Zinc; 7440–66–6 Linuron; 330–55–2

MTBE; 1634–04–4.

Molinate; 2212–67–1.

Nitrobenzene; 98–95–3.

Prometon; 1610–18–0.

RDX; 121–82–4.

Rhodamine WT.

Terbacil; 5902–51–2.

Terbufos; 13071–79–9.

EPTC; 759–94–4.

B. Perchlorate

Additional information and comment

is sought on the inclusion of perchlorate

on the final CCL. Perchlorate is being

mentioned in this notice because EPA

received information that it had been

detected in water in the Colorado River

and in wells in California, but the

information came too late in the process

of developing the draft CCL to evaluate

it as had been done for the other

contaminants. The information the

Agency has received regarding

perchlorate’s occurrence, health effects,

source of contamination and treatment

that has been included in the docket.

This information, and any other

submitted in response to comments, as

well as additional data that the Agency

may obtain, will be considered to

determine whether perchlorate should

be included on the final CCL.

VI. Development of the Final Drinking

Water Contaminant Candidate List, the

Contaminant Identification Method,

and the Contaminant Selection Process

Between now and the publication of

the final CCL, the Agency will evaluate

comments received during the comment

period for this notice and re-evaluate

the criteria used to develop the draft

CCL and revise the CCL, as appropriate.

The final CCL will be published by

February 1998. In addition to publishing the final

CCL, the Agency will also resume work

on the CIM and the contaminant

selection process. The development of

the CIM and the selection process will

be completed in consultation with the

NDWAC Working Group on Occurrence

& Contaminant Selection. The next

meeting of the Working Group will

likely be later this fall. The CCL, CIM

and the selection process will serve as

the cornerstones of the Agency’s

regulatory development process. In

addition to developing the CCL, CIM

and the selection process with the

Adminstration policy in mind, the

Agency intends to obtain resources to

improve the screening process in order

to acquire better information, improve

analytical capability, and seek

additional stakeholder involvement.

The CCL is a critical input to shaping

the future direction of the drinking

water program, and improvements will

be made with each successive cycle of

publishing the list.

VII. Summary of Other Related Activity

Required by the SDWA

After the CCL is developed and in

accordance with the SDWA, as

amended, the Agency will determine

whether or not regulation is needed for

at least five contaminants. This step of

contaminant selection is then followed

by proposal and ultimate promulgation

of regulations for those contaminants for

which a determination has been made to

regulate. Two tools provided for in the

SDWA, as amended, that relate to

development of the CCL, are the
52214 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

occurrence database and unregulated

contaminant monitoring. In identifying

contaminants for inclusion on the CCL,

and selecting contaminants for

determination, the National Drinking

Water Contaminant Occurrence

Database must be considered. The

primary mechanism for obtaining the

occurrence data for the database is the

Unregulated Contaminant Monitoring

Requirements provision. Figure 2

provides a representation of the

relationship among these various

elements. The SDWA requirements for

contaminant selection, the occurrence

database and unregulated contaminant

monitoring are presented below to give

the reader a sense of what these

requirements entail and how they relate

to the CCL and to each other.

BILLING CODE 6560–50–P
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52215

BILLING CODE 6560–50–C
52216 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

A. Contaminant Selection and

Regulatory Determination

The SDWA, as amended in 1996,

requires EPA to make determinations of

whether or not to regulate no fewer than

five contaminants from the CCL five

years after enactment (i.e., by August

2001), and every five years thereafter

(section 1412(b)(1)); which is also three

and a half years following each CCL.

Any of the contaminants from the CCL

that the Agency decides to regulate are

subject to proposed NPDWRs within 24

months of this decision to regulate, and

final NPDWRs within 18 months of the

proposal. The SDWA also requires that

EPA give priority to selecting

contaminants for regulation that present

the greatest public health concern,

including vulnerable populations such

as infants, the elderly, and those with

serious illness. Three criteria must be

considered when deciding whether or

not to regulate a contaminant: (1) Could

the contaminant adversely affect public

health, (2) is it known or substantially

likely to occur in public water systems

with a frequency and at levels posing a

threat to public health, and (3) will

regulation of the contaminant present a

meaningful opportunity for health risk

reduction.

The Agency will be developing a

contaminant selection process that will

address the criteria mentioned above in

concert with the contaminant

identification method. The contaminant

selection process will be used to select

contaminants from the CCL for which

determinations will be made, while the

CIM will be used to develop the CCL.

A conceptual approach for the CIM was

presented on December 2–3, 1996, at an

EPA sponsored stakeholders meeting

(U.S. EPA, 1996b) However, in order to

meet the February 1998 deadline for

finalizing the CCL, further work on the

CIM was delayed in favor of developing

the draft CCL presented in today’s

notice. The Agency, in collaboration

with the NDWAC Working Group on

Occurrence & Contaminant Selection,

will resume work on the CIM and the

contaminant selection process during

the fall of 1997. Knowledge gained

during the development of this draft

CCL, as well as the feedback received

since the December 1996 stakeholders

meeting, will be factored into the

development.

B. The National Contaminant

Occurrence Database

The SDWA, as amended in 1996,

requires EPA to establish a national

drinking water contaminant occurrence

database (NCOD) to be assembled by

August 1999 [section 1445(g)]. The

database is to include the occurrence of

both regulated and unregulated

contaminants, and, once established, is

to be used to support the

Administrator’s determinations for

future regulations. The requirements for

developing the CCL also include

consulting the occurrence database.

Since the database is currently under

development, and will not be available

for the development of this first CCL,

the Agency consulted other sources of

occurrence data. Once available,

however, the NCOD will be used not

only to develop future CCLs and

support future determinations of the

need for regulations, but to develop

future regulations.

A Stakeholder meeting was held on

May 21–22, 1997, in Washington, D.C.,

on the NCOD to discuss and obtain

input from the public, states, and the

scientific community on database

design and structure, input parameters

and requirements, and the uses and

interpretation of the data. This meeting

was the first of several expected to take

place in the near future regarding the

NCOD development.

C. Unregulated Contaminant Monitoring

Regulation

The SDWA, as amended, requires

EPA to list and develop regulations for

monitoring of certain unregulated

contaminants by August 1999, and

every 5 years thereafter (section

1445(a)(2)). This provision was first

introduced with the 1986 amendments

to the SDWA and has been substantially

modified by the 1996 amendments. The

SDWA requires that the list of

unregulated contaminants not exceed

30, and that the monitoring data be

collected and maintained in the NCOD.

Criteria for determining which

contaminants on the CCL will be chosen

for the unregulated contaminant

monitoring list will be developed as part

of this regulation.

Contaminants on the CCL that need

additional occurrence data will be used

as the principal source of contaminants

for the list of unregulated contaminants.

The unregulated contaminant

monitoring provision of the SDWA will

be used as a tool to gather the

contaminant occurrence data necessary

for determining the need for drinking

water regulations.

VIII. Summary of Concurrent

Regulatory Activity Required by the

SDWA

In addition to the requirements for the

CCL and contaminant selection, the

SDWA, as amended 1996, also contain

specific provisions with regard to radon,

arsenic, sulfate, and disinfectants and

disinfection byproducts. The SDWA, as

amended, did not specify a new time

frame for finalizing rulemaking for other

radionuclides, however, EPA and the

Bull Run Coalition have entered into a

consent decree with the court

establishing timetables to finalize this

rulemaking. Regulatory activity for

radon, other radionuclides, arsenic,

sulfate, and disinfectants and

disinfection byproducts are not affected

by today’s notice, but are summarized

below to provide the reader with an

update on the status these specific

activities.

A. Radon

The SDWA, as amended in 1996,

contains specific provisions for

regulating radon in drinking water

(section 1412(b) (13)). First, EPA is

required to withdraw the proposed rule

for radon which was published in 1991

and to re-propose a drinking water

regulation for radon by August 6, 1999,

and issue final regulations by August 6,

2000. The SDWA, as amended, also

requires EPA to: (1) Arrange for the NAS

to prepare a peer reviewed risk

assessment for radon that evaluates the

health effects of radon in drinking water

under conditions likely to be

experienced through residential

exposure and to assess the risk

reduction benefits from various

mitigation measures to reduce radon

levels in indoor air; (2) make available

for public comment a health risk

reduction and cost analysis comparing

costs and benefits of various possible

MCL in advance of proposing a radon

regulation; and (3) establish an

alternative-MCL, if the MCL is set at a

level that is more stringent than

necessary to reduce the contribution of

radon in indoor air originating from

drinking water to a level equal to the

national average concentration of radon

in outdoor air. States will have the

option to comply with the less stringent

alternative-MCL if they implement a

multi-media radon risk reduction

program that accomplishes greater

health protection than would be

achieved by complying with the more

stringent MCL alone.

A notice was published in the Federal

Register on August 6, 1997, to withdraw

the radon proposed rule. (62 FR 42221)

The NAS risk assessment is scheduled

to be complete by July 1998, and the

HRRCA is due by February 1998. In

addition, EPA held stakeholder

meetings on June 26, 1997, in

Washington, D.C., and on September 2,

1997, in San Francisco, and has

scheduled an additional stakeholder

meeting in Boston later this fall to

obtain input from the public.
Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices 52217

B. Other Radionuclides

On July 18, 1991, EPA proposed

NPDWRs for radionuclides in public

water supplies (56 FR 33050). EPA

proposed MCLs for Radium-228 at 20

pCi/l, Radium-226 at 20 pCi/l, Uranium

at 30 pCi/l (20 μg/l), adjusted gross

alpha at 15 pCi/l (excluding Ra-226, U,

and Rn-222), and beta and photon

emitters (excluding Ra-228) at 4 mrem

ede/yr; MCLGs were proposed at zero.

Comments on the proposed rule were

received from approximately 600

individuals and organizations. Due to

concerns by commenters and Congress

over the most effective way to regulate

radon and other radionuclides together,

the proposed rule was put on hold,

pending passage of amendments to the

SDWA, so that EPA could gain further

clarification of Congress’ intent.

The SDWA, as amended in 1996, did

not specify a new time frame for

finalizing rulemaking for radionuclides,

as it did for radon. However, an existing

consent decree providing deadlines for

regulating radionuclides was amended

in 1996 to provide that EPA would, by

November 2000, finalize a rule for

Uranium; and finalize a rule for Ra-226,

Ra-228, alpha and beta/photon emitters,

or publish its reasons for not taking final

action as to these contaminants. An

Agency Workgroup has been formed

and is process of evaluating all current

data and information, which will lead to

finalizing elements of the proposed rule

or to re-proposing NPDWRs for

radionuclides.

C. Arsenic

In 1975, EPA established National

Interim Primary Drinking Water

Regulations (NIPDWR), setting an MCL

for Arsenic at 50 μg/l. In 1985, EPA

proposed an MCLG of 50 μg/l,

requesting comment on alternate

MCLGs of 100 μg/l and 0 μg/l. However,

the SDWA, as amended in 1986,

converted the interim standard into a

NPDWR, subject to revision by 1989.

When the Agency failed to meet the

statutory deadline for promulgating an

arsenic regulation, a citizen’s group

filed suit to compel EPA to do so. EPA

entered into a consent decree to, in part,

issue the arsenic regulation. The

consent decree was amended several

times to extend the deadlines and with

passage of the 1996 Amendments was

dismissed as to arsenic.

The SDWA, as amended, requires

EPA to conduct additional research on

arsenic in order to reduce the

uncertainty in assessing the health

effects of low exposure levels; to

propose a NPDWR for arsenic by

January 1, 2000; and to issue a final

regulation by January 1, 2001. (Sec.

1412(b)(12)) EPA developed a research

plan, made it available for public

comment, and had it peer reviewed in

January 1997. The revised research plan

will be available this fall. In addition,

EPA issued a joint request for research

proposals with the American Water

Works Association Research Foundation

(AWWARF) and the Association of

California Water Agencies (ACWA).

EPA, AWWARF and ACWA awarded

almost $3 million in grants and

contracts this summer, for up to three

years. This spring, EPA also funded an

Interagency Agreement, with the

National Research Council (NRC) of the

NAS to review EPA’s risk assessment,

determine the adequacy of EPA’s

current MCL for protecting human

health and surface water quality criteria,

and identify priorities for research to fill

data gaps. The NRC report will be

submitted to EPA in mid-to-late 1998. In

May, 1997, EPA convened an expert

panel to evaluate the scientific literature

on the genetic and carcinogenic effects

of arsenic in order to comment on

arsenic’s mode of action and the data

supporting models extrapolating to low

dose arsenic exposures. The final report

is now being considered by EPA’s IRIS

Update Group.

D. Sulfate

A December 20, 1994 proposed sulfate

regulation contained both MCLG and

MCL levels for sulfate of 500 mg/l and

included 4 alternative compliance

options designed to allow flexible

implementation. Thereafter, the

Agency’s drinking water redirection

effort concluded that sulfate was a

relatively low risk contaminant, and

further regulatory activity was

suspended. The SDWA, as amended,

requires completion of a study to

resolve risk questions and requires the

Agency to make a determination within

5 years of enactment of the

Amendments, by August 6, 2001, of

whether or not to regulate sulfate. Any

of the contaminants from the CCL that

the Agency decides to regulate are

subject to proposed NPDWRs within 24

months of this decision to regulate, and

final NPDWRs within 18 months of the

proposal. In 1997 the Agency entered

into an Interagency Agreement with the

Center for Disease Control and

Prevention (CDC). EPA and CDC are

currently waiting for completion of the

peer review of the jointly planned

health risk study for sulfate. The study

results, due in February 1999, will serve

as input for EPA’s contaminant

identification and selection protocol to

decide whether or not to regulate

sulfate, and will be publicly available.

In addition, prior to deciding on the

need to regulate sulfate, the Agency

would need to make a determination on

the adequacy of existing occurrence data

for sulfate and, if inadequate, consider

approaches for filling data gaps.

E. Disinfectants and Disinfection

Byproducts

Microorganisms identified for the CCL

are not specifically targeted by the

following regulations, however they

may be indirectly controlled. Any

microorganism identified for the CCL

which is determined later to be

adequately, although indirectly,

controlled by the following regulations,

will be subsequently withdrawn from

the CCL.

Under the Surface Water Treatment

Rule (SWTR) promulgated on June 29,

1989, (54 FR 27486), EPA set MCLGs of

zero for Giardia lamblia, viruses and

Legionella; and promulgated NPDWRs

for all public water systems (PWSs)

using surface water sources or

groundwater sources under the direct

influence of surface water. The SWTR

includes treatment technique

requirements for filtered and unfiltered

systems that are intended to protect

against the adverse health effects of

exposure to Giardia lamblia, viruses,

and Legionella, as well as many other

pathogenic organisms.

In 1992, EPA initiated a negotiated

rulemaking to develop disinfectant and

disinfection byproducts regulations. The

Regulatory Negotiating Committee met

from November 1992 through June 1993

and included representatives of State

and local health and regulatory

agencies, public water systems, elected

officials, consumer groups and

environmental groups. One of the major

goals addressed by the Committee was

to develop an approach that would

reduce the level of exposure from

disinfectants and disinfection

byproducts without undermining the

control of microbiological pathogens. To

accomplish this, the Committee agreed

to the development of three sets of

regulations: a two-staged Disinfectant/

Disinfection Byproducts Rule (D/DBP),

an Enhanced Surface Water Treatment

Rule (ESWTR), and an Information

Collection Rule (ICR). The purpose of

the ICR is to collect occurrence and

treatment information to evaluate the

need for possible changes to the current

SWTR, existing microbial treatment

practices, and also evaluate the need for

future regulation for disinfectants and

disinfection byproducts.

EPA would first develop an InterimESWTR (IESWTR) that would only

apply to systems serving 10,000 people

or more, the committee agreed that a
52218 Federal Register / Vol. 62, No. 193 / October 6, 1997 / Notices

Long-Term-ESWTR (LTESWTR) may be

needed for systems serving fewer than

10,000 people when the results of more

research and water quality monitoring

became available. The LTESWTR could

include additional refinements for larger

systems.

The ICR was proposed on February

10, 1994 (59 FR 6332) and promulgated

on May 14, 1996 (61 FR 24354). The D/

DBP regulations and the IESWTR were

proposed on July 29, 1994 (59 FR 38668,

59 FR 38832). The SDWA, as amended,

requires EPA to promulgate an IESWTR

and a Stage I D/DBP Rule by November

1998. In addition, the SDWA requires

EPA to promulgate a final ESWTR and

a Stage II D/DBP rule by November 2000

and May 2002, respectively [section

1412(b)(2)(C)].

In light of new information that has

become available in several key areas

related to issues put forth in the D/DBP

Stage 1 proposal, the Agency initiated a

series of public meetings in May 1996.

These meetings were designed to

exchange information on issues related

to the development of the IESWTR and

the Stage 1 D/DBP rule and the impact

of the ICR data not being available. In

order to facilitate moving in an

expedited fashion to meet the deadlines

in the 1996 Amendments, and to

maximize stakeholder participation, the

Agency subsequently established an

advisory committee to collect, share,

and analyze new information and data

as well as to build consensus on the

regulatory implications of this new

information. After evaluation of the new

data and information, the committee

made recommendations on a number of

major issues. These recommendations

and a discussion of the pertinent issues

will be published in a Federal Register

Notice planned for later this fall.

IX. Other Requirements

The CCL is a notice and not a

regulatory action; therefore, the

following statutes and executive orders

are not applicable at this time: the

Regulatory Flexibility Act, Small

Business Regulatory Enforcement

Fairness Act, Paperwork Reduction Act,

Unfunded Mandates Reform Act; and

Executive Order 12866. As

contaminants are selected for

rulemaking, all necessary analysis will

be conducted in accordance with the

rulemaking process.

Executive Order 13045, Protection of

Children from Environmental Health

Risks and Safety Risks, requires that

Federal Agencies identify and assess

health risks and safety risks that

disproportionately affect children, and

ensure that its policies, programs,

activities, and standards address

disproportionate health and safety risks

to children. The SDWA also requires the

Agency to select priorities for regulation

while considering risk to sensitive

subpopulations, such as infants and

children.

The impact on sensitive populations

will be addressed in the contaminant

selection process, and will be a

component of the Agency’s

determination of whether or not to

regulate a given contaminant. In

preparation for addressing the issues of

sensitive subpopulations, the Agency is

sponsoring several activities to

determine water intake by age group, by

demographic distribution, and by innate

or developed sensitivity to potential

drinking water contaminants. The

Agency is also collaborating with CDC

on a study of six major cities to

determine the most sensitive

populations for drinking water

manifested during major outbreaks of

illness from incidents of water

contamination. Other research also is

underway to determine the extent of

vulnerable populations including

children and the immunologically

impaired.

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(Authority: 42 U.S.C. 300f–300j–25)

Dated: September 29, 1997.

Robert Perciasepe,

Assistant Administrator, Office Water,

Environmental Protection Agency.

[FR Doc. 97–26433 Filed 10–3–97; 8:45 am]

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