Monday
.January 14, 1991
 Part V



 Environmental

 Protection  Agency

 Priority List of Substances Which May
 Require Regulation Under the Safe
 Drinking Water Act; Notice

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 1470
•Federal Register /  Vol.' 58,  No/9 / Monday. January 14, 1991 / Notices
 ENVIRONMENTAL PROTECTION
 AGENCY

 IOW-FRL-38S6-5)         •;'•••

 Priority Ust of Substances Which May
 Rtqulre Regulation Under the Safe
 Drinking Water Act

 AGENCY: Environmental Protection
 Agency (EPA).
 ACTION: Notice.  • •	-.    .

 SUMMARY: The Safe Drinking Water Act
 as amended in 1986 requires EPA to
 publish a triennial list of contaminants
 which are known or anticipated to occur.
 in drinking water and which may
 require regulation under the Act The
 Drinking Water Priority List (DWPL)
 serves as a list of candidate
 contaminants for regulation under the
 Act EPA published the first DWPL
 containing 53 contaminants/
 contaminant groups on January 22,1988.
 The present notice establishes a revised
 DWPL (1991 version) of "candidates" for
 future regulations. The list is comprised
 of 50 substances carried over from the
 1988 DWPL and 27 new substances..The
 total number of contaminants/
 contaminant groups on the revised   '
 DWPLis77.                  .  '
 DATEST This notice is effective
 immediately.
 ADDRESSES: References and supporting
 documentation for new substances
 selected for the list are in the public
 docket. Supporting documents for the
 substances carried over from the 1988
 list are not being made available again.
The docket clerk's office is located in
 the Criteria and Standards Division.
 Office of Drinking Water, U.S.       :
Environmental Protection Agency, 401M
 Street, SW« Washington, DC 20460. The
 docket is open from 9 a.m. to 3:30 p.m.,•
Monday through Friday, except legal
holidays. Please call 202-382-3027 for art
 appointment to inspect the docket.
 FOR FURTHER INFORMATION CONTACT: ,
JItendra Saxena, Ph.D., Criteria and
Standards Division. Office of Drinking
Water (WH-550D), U.S. Environmental
Protection Agency, 401M Street. SW.,
Washington, DC 20460. phone 202-475-,.
9579. General information may also be  •
obtained from the EPA Drinking Water
Hotline. The toll-free number is B00-426rr.
4791; the local number is 202-382-5533.   '

EPA Regional Offices • •     •  . • •
L JFKfFederal'Bldg., room 2203; Boston,'.
    MA 02203, Phone; (617) 85373610,",
    Jerome'Healey. ''..'."'"   ' '   ' .'.'.
H. 28 Federal Plaza, room 824. New ".": ".;
    York/NV'i0278,'Phb.rie.'(212)  264^' I ;:
    1800, Walter Andrews.      • "''" '
                    m. 841 Chestnut Street; Philadelphia. PA
                        19107, Phone: (215) 597-8227, Jon
                     •  . Capacasa.      '•«-'.      •  -
                    IV. 345:Courtlaiid Street ME., Atlanta.  .
                        GA 30365, Phone: (404) 347-3866.   ;
                        James Kutzman.       '         .
                    V."230 Dearborn Street, Chicago, EL
                        60604.' Phone: (312) 353-2151,   -
                        Edward P. Watters.
                    VI. 1445 Ross Avenue, Dallas, TX 75202,
                        Phone: (214) 255-7150. Oscar Cabra.
                   • Vn. 726 Minnesota Ave., Kansas City,
                        KS 66101, Phone: (913) 551-7032,  ..
                        Ralph Langemeier.       .  •   ; '
                    Vffl. One Denver Place, 99918th Street
                        suite 500, Denver, CO 80202, Phone:"
                        (303) 294-7005, Patrick  Grotty..
                    DC. 74 Hawthorne Street, San Francisco,
                        CA 94105, Phone: (415)  774-2250,
                        Steve Pardieck.   •
                    X. 1200 Sixth Avenue, Seattle, WA
                        98101, Phone: (206) 399-4092, Jan
                        Hastings.           '
                    SUPPLEMENTARY INFORMATION:  "  '

                    Table of Contents
                    I. Background    .            .
                    n. Selection of Contaminants for the Revised
                       Drinking Water Priority List     .
                     A. 1988 Drinking Water Priority List .
                     B. Lists of Substances Considered for   "  .
                       Revision of the Drinking Water Priority
                       List
                     1. SARA Priority last             •
                     2. Pesticides Registered Under FIFRA -
                     a. Pesticides Selected Based  on the Results
                       of the National Pesticides Survey
                     b. Pesticides Selected Based on Their
                       Leaching Potential
                     3. Substances Recommended by States and
                       EPA Regions
                    m. 1991 Version of the Drinking Water
                       Priority List • . •                    -
                    IV. Future Revisions of the Drinking Water  -.-'•
                       Priority List   . ...
                    V. Other Requirements .  .       •   ,.;
                     A. Executive Order 12291        .
                     B. Regulatory Flexibility Act
                     C. Paperwork Reduction Act
                    VL* References    •   -  •      '     , .   .

                    Abbreviations Used In this Notice  ..  '.
                    ATSDR: Agency for Toxic Substances and,
                       Disease Registry      ,      •• •      '
                    CERCLA: Comprehensive Environmental
                       Response, Compensation, and Liability  . .
                       Act (Superfund)
                    DWPL: Drinking Water Priority List'  -.""..:
                    FIFRAi Federal Insecticide,' Fungicide and
                       Rodertticide Act
                    FSTRAC: Federal-State Toxicology and
                       Regulatory Alliance Committee
                    MCL: Maximum Contaminant Level  , ..    ...
                    MCLG: Maximum Contaminant Level Goal . .•
                    NPL: National Priority list (Superfund)
                    NFS: National Pesticidea Survey  .'.
                    NTP: National Toxicology Program ' •" '  '* '•
                    NPDWR.-:National Primary Drinking Water '
                       Regulation (includes both Interim and '' •
                       Revised National Primary-Drinking-- '•>••: f.
                       WaterRegulations). - .-.J.j-.  ;. .,:'• v-.-'-V' -j
                    ODWtQffice'of Drinking Water. -::•,=._ ;••;,,-
                    SARA: Superfund Ajnendments and., >!-„ ,. -,f
                       Re'a'uthofizatibri Act"' •  " "    "  -.''.:
 SDWA: Safe Drinking Water Act, also
     referred to as "the Act," as amended in .
     198a  .   .      •   ....-.'
 SMCL; Secondary Maximum Contaminant'
     Level                .
 TRI: Toxics Release Inventory
 VOC: Volatile Organic Chemical

 L Background
   The Safe Drinking Water Act,{SDWA
 or "the Act"), as amended in 1986,
• requires the Environmental Protection
 Agency (EPA) to publish a triennial list
 of contaminants ("Drinking Water
 Priority List" or DWPL) which are -
 known or anticipated to occur in
 drinking water and which may require
 regulation under the Act .[section  .
 1412(b)(3)(A)]. EPA must propose
 National Primary Drinking Water •
 Regulations (NPDWRs) for at least 25
 contaminants on'the DWPL within 24
 months after publication of each
 triennial list and promulgate 25
 NPDWRs Within 36 months of
 publication of each triennial list. Under
 section 1401 of the Act, the NPDWRs are
 to include maximum contaminant levels
 (MCLs) and "criteria and procedures to
 assure a supply of drinking water which
 dependably complies" with such MCLs.
 If it is not economically or technically
 feasible to ascertain the level of a
.contaminant in drinking water, EPA may
 require the use of a treatment technique
 instead of an MCL
   In selecting contaminants  for the list,
 EPA must consider, at a minimum,
 substances referred to in section 101(14)
 of the Comprehensive Environmental
 Response, Compensation and Liability
 Act of 1980 (CERCLA or "Superfund")
 and pesticides registered wider the
 Federal Insecticide, Fungicide, and
 Rodenticide Act (FIFRA). The Act also
 requires EPA to form an advisory' group
 to  assist in developing the DWPL! This
 group must include, but.not be limited
 to, participants from the National
 Toxicology Program and the EPA offices
 of Drinking Water, Pesticides and Toxic
 Substances, Ground Water, and Solid
, Waste and Emergency Response, and
• other offices deemed appropriate by the
 Administrator.    .      • . •'
;  The first Drinking Water Priority List
 was published by EPA on January 22,
 1988 (53 FR1892). The.li.st consisted of   :
 53  contaminants/contaminant groups,  ,.•„.
 and included the seven substances  ,
 which were removed from the original
 statutory list of 83  contaminants. Other.. ,
 contaminants placed on the list  included
 disinfectants and. their .by-products,,-;,,;,-.,
 priority contaminants developed under..,,
• the Superfund Amendments and . ,  -:.,,
 Reauthorization Act (SARA)< design; -••
 analytes.of the EPA National. Pesticides ..
 Survey (NPS), unregulated contaminants

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                    Federal Register / Vol. 56, No. 9 / Monday, January 14,  1991 / Notices
                                                                      1471
 monitored under section 1445 of the
 SDWA, and certain substances reported
 frequently and at high concentrations in
 drinking water surveys.  .   -
   EPA is complying with SDWA
 requirements for publication of a   .
 triennial list of contaminants by revising
 and updating the 1988 DWPL. EPA
 believes that the DWPL is simply a list
 of "candidates" for regulation. These .
 "candidates" include substances which
 are known or anticipated to occur in
- drinking water and which may require  ,
 regulation under the Act. Some
 substances are placed on the list
 because they clearly present a health
 risk; others will require further
 investigation before the need for
 regulation is clear. With .this approach,
 the DWPL will be a flexible tool which
 is reviewed and revised every three  •.
 years. Contaminants which no longer
 meet the EPA's DWPL criteria, or which
 have been regulated since being placed
 on the list, can be dropped, and new
 high-priority drinking water
 contaminants can be added to the list
 when it is revised.      .        .     .
   This notice establishes a revised list
 of "candidate" contaminants for future
 regulation. EPA has not yet promulgated
 NPDWRs for any contaminants from the
 1988 list. Fifty substances from the 1988
 list which continue to meet the DWPL
 criteria have been carried forward to the
 1991 list. Three  substances from the 1988
 list have been dropped (s.ee discussion.
 below). .Twenty-seven new drinking
 water contaminants have been added.
   This notice was developed with the
 assistance of the DWPL workgroup. The
 workgroup was chaired by the Criteria
 and Standards Division, Office of -
 Drinking Water. The workgroup
 consisted of representatives from the
 EPA offices of Pesticides and Toxic
 Substances, Ground Water, Solid Waste
 and Emergency Response, and other
 programs within the Agency; the
 National Toxicology Program (NTP); the
 U.S. Geological Survey; and the Agency
 for .Toxic Substances and Disease'' •.   •
; .Registry (ATSDR).           •    -;   •
 II. 'Selection of Contaminants for the    ;
. Revised Drinking Water Priority List •  : .
 ; Drinking-water contamination  !
 generally occurs from: (a) Contaminants
 that find their way into drinking water
  sources froin industrial waste,     ; '•
  agricultural runoff, and other pollution
  sources; (b) contaminants formed during;
  treatment of water-supplies (e-g.. • ;•
 disinfection! by-products); and (c)  :; •
 .materials used for treatment, storage,
  and distribution of water (e.g., direct
. and indirect additives). EPA^as Y..Y
  considered all of these sources in!  ;
  selecting important,: or potentially,
important, drinking water contaminants
for the 1991.DWPL
  EPA used the following general
criteria_f6r contaminant"selection for the
1988 DWPL, and has used the same.
criteria in revising the DWPL:
—Occurrence of the substance in public
  water systems; or physical/chemical/
  environmental characteristics and use
  patterns of the substance indicate its
  potential for occurrence in public
  water systems at levels of concern.  .
—Documented or suspected adverse
.  health effects of the contaminant.   -
—Availability of sufficient information
  on the substance, including health
  effects data, analytical methods, and
  treatability studies, so that a
  regulation could be developed within
  the statutory time frame.
  Alternatively, there should be
  sufficient likelihood that needed
  information on the contaminant can
  be developed so that a regulation
  could be developed before the
  statutory deadline.
  All contaminants on the 1991 DWPL
meet these selection criteria.
A. 1988 Drinking Water Priority List
  The 1988 DWPL contained 53    ;
contaminants/contaminant groups (53
FR 1892, January 22,1988). It included
seven contaminants removed from the
statutory list of 83 contaminants, and
substances selected .from the following
groups: (1) Disinfectants and
disinfection by-products, (2) the first 50
contaminants on the SARA section 110
priority list, (3) design-analytes of the
EPA National Pesticides Survey, (4) .
unregulated volatile organic chemicals
 (VOCs) listed under monitoring
 requirements of section 1445 of the
 SDWA, and (5) other substances
 selected for specific reasons articulated
 in the January 22,1988, Federal Register
 notice.
   EPA was required to propose
 NPDWRs for at least 25 contaminants
 on the DWPL by January 1990 and to
 promulgate fee NPDWRa by January
 1991. EPA has not met this schedule and
 therefore is carrying forward to the 1991
 list all the contaminants/contaminant
 groups on the 1988 DWPL except as;  ;
 discussed below. Those contaminants
 carried forward continue to meet DWPL
 selection criteria. EPA plans to propose ;
 NPDWRs for 25 contaminants in June
 1993 that will be selected from the
 revised(1991)DWPL.   i,! k-;       .
   Three contaminants on the 1988: .;, ,. ?
 DWPL—ammonia, silver, and sodium-
 have been determined to be of low
 priority for regulation and, therefore,'
 have been dropped from the 1991 list. -
 For each of these three substances, there
 is either little or no potential for
 exposure via drinking water, or no
 adverse health effect associated with  "
 their presence in drinking -water. Current
 data for ammonia indicate, no adverse
 health effects on humans at levels found
 in drinking water. Long-term exposure to
 silver is known to cause argyria, a
 grayish discoloration of the skin. Since
 this is considered a cosmetic effect and
 not a health effect, a secondary         •
 maximum contaminant level (SMCL)
 was proposed for silver (54 FR 22062,
 May 22,1989). SMCLs are not federally
 enforceable and are established for
 contaminants in drinking water which  .
 may affect the  aesthetic qualities and
 the public's acceptance of drinking
 water. Sodium is low priority because    .
 drinking water contributes only a small
 fraction of total dietary intake. In
 addition association between sodium hi
 drinking water and hypertension hi the
 general population is based on
 inadequate data (50 FR 46980, November
 13,1985). Any of these three chemicals   .
 could be added to a subsequent DWPL
 should new data warrant such action.

 B. Lists of Substances Considered for
 Revision of the Drinking Water Priority
 List
   The following sources were reviewed ;
 by EPA to identify contaminants for the
 1991 version of the DWPL.     .     .

 1. SARA Priority List

   The Superfund Amendments and
 Reauthorization Act of 1988 (Pub. L. 99-
 499 (SARA)) amended and extended
 CERCLA of 1980 (42U.S.C. 9601 et seq.).
 SARA (section 110) requires the Agency
 for Toxic Substances and Disease
 Registry (ATSDR) of the Department of  -
 Health and Human Services and EPA to
 prepare a.priority-ordered list of    •  •  .
 hazardous substances covered by
 CERCLA. The list must consist of those.
 substances which are most commonly
• found at hazardous waste sites on the
 .CERCLA National Priority List (NPL),
 and which the agencies determine pose
 the most significant potential threat to
 human health. The first list of 100
 substances was published in the Federal :
 Register on April 17,1987 (52 FR 12866).,
 The list was separated into four priority
 groups of 25 substances each. The first
 group of 25 is  the highest priority group,
  the second is the next highest priority,
  and so on. The use of the SARA list in
  the development of the DWPL fulfills the
  SDWA requirement to consider.
  CERCLA section 101(14) substances. •
  This was discussed in detail, hi the 1988
  DWPL Notice {53 ER1892, January 22.
  1988).                    ,

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 1472
Federal  Register / Vol. 56.  No. 9 / Monday. January 14.  1991 / Notices
   EPA considered substances in priority ,
 groups 1 and 2 of the first SARA list for
 the 1888 DWPL. During revision of the
 DWPL. EPA reexamined those
 substances taking Into -consideration
 new data which were generated since
 1988. EPA also considered substances in'
 priority groups 3 and 4. SARA priority
 list substances which were selected for
 the 1991 DWPL are listed in Table 1.
 TABtE 1.— SARA SECTION 110 PRIORITY
   LIST SUBSTANCES WHICH  HAVE  BEEN
*   SELECTED FOR THE 1991 DWPL

 AcrytooHrifr                          ~~
 DtchlonxSfiuororrttthvM
 2,4-DHtroptwnol
 2,B-OWtfoto»u»o«
 1,2-Ofcbwiylhydwzio*
 Fiooretrichlororndtharw
   Naphthalene is. the only substance
 listed in Table 1 which was considered.
 previously for the 1988 DWPL.  ,
 Naphthalene was excluded from the
 1988 list because of little or no potential
 for exposure through drinking water.
 Revaluation of naphthalene has,
 however, revealed a strong potential for
 drinking water contamination. For
 example, naphthalene may leach into
 drinking water from coal tax based
 protective coatings used in water
 transmission lines and storage -tanks.
 Also, a substantial increase in the
 amount of naphthalene released to the
 environment has been reported (U.S.
 EPA, "Toxics Release Inventory,"
 National Report, 1988), -suggesting the
 possibility of drinking water •       ,  •••
 contamination. Therefore, naphthalene
 has been Included in the 1991 DWPL.
   Substances included in the second
 SARA list (54 PR, October 20, 1988) and
 the third SARA list (53 FR, October 26,
 1980) will be considered for future
 DWPLs.
 2. Pesticides Registered Under FIFRA
   Pesticides are logical candidates For
 Inclusion on the DWPL. Since pesticides
 are specifically developed for their
 toxicity to -certain organisms, the
 potential exists for their toxicity to
 humans. Also, there is  mounting
 evidence that pesticide use -can. in some
 circumstances, lead to contamination of
 drinking water supplies. EPA used *wo
 mechanisms to select pesticides for the
 1091 version o£ the DWPL:  -  ,
   a. Pesticides Selected Based on the  •
 Results of ths National Pesticides  ••
 Survey. The National Pesticides-Survey •
 (NPS) wasa-joindysponsored project of
                   EPA's Office of Drinking Water (ODW)
                   and Office of Pesticide Programs (OPP).
                   It was the first national survey of
                   pesticides and pesticide' degradation
                  , products in drinking water wells. The
                   survey had two principal objectives: (1)
                   To determine the frequency and
                   concentration of pesticide.
                   contamination of drinking water wells
                   nationally: and (2) to improve EPA's
                   understanding of how contamination of
                   drinking water wells is associated with
                   patterns of pesticide use and the
                   vulnerability of ground water to
                   contamination. The survey involved
                   analysis of 127 pesticides and pesticide
                   degradation products in statistically
                   representative samples taken from more
                   than 1,300 wells, some, in every State.
                     The pesticides listed in Table Z have
                   been selected for the revised DWPL
                   because of their frequeqt reported
                   detection in drinking water wells.
                   Furthermore, these pesticides also- meet
                   the other DWPL criteria.
                   •TABLE  2.— PESTICIDES  SELECTED
                     THE 1991 DWPL BASED ON THE  RE-
                     SULTS OF THE NATIONAL PESTICIDES
                     SURVEY

                   Bentazon
                   DCPA (and its add metabolites)   -  . .
                   Parathion degradation .product <4-Nitrophenol)
                   Prometon ,


                     b.Pesticides Setected Based on Their
                   Leaching Potential. Ground-water
                   contamination by pesticides has been of '
                   considerable public concern over the
                   last several years, The Agency, through
                   its pesticide registration and  ~
                   registration process, has -focused its
                   attention on identifying and developing
                   information on pesticides which have
                   . the greatest potential to leach into
                   ground water. A complex «etnf factors
                   influence the likelihood of pesticide
                   contamination of ground water in a
                   given location: The physical and
                   chemical'properties of the pesticide,   : •
                   natural hydrogeologic and man-made
                   features at the site of application, and •
                   the .agronomic and pesticide application
                   practices employed. Pesticides that -
                   leach into ground water are .also
                   potential contaminants of surface •
                   waters. 'The NPDWRs apply to drinking
                   water -from -both sources.
                     As part of the registration/ •
                   reregistration process, EPA has required
                   ground-water -monitoring studies from • •
                  . the registrants on 36 pesticides. These
                   •pesticides are considered excellent     .
                   candidates for the 1991 DWPL because
                   (1) they .have properties and  .
                   •"characteristics associated with -other , , ; .
                   pesticides previously detected ingrourul
water, and (2) much of .the .information
on these pesticides which may be
needed for regulationiias already been
developed by the registrants. However,
many of the pesticides on the list of 36
have already been considered for
drinking water regulation via other
mechanisms. For example, they appear'
on the statutory list of 83 or on the 1988
DWPL or are analytes of the National
Pesticide Survey. For the revised DWPL.
EPA has selected from the 36 pesticides .
only those which meet the DWPL
criteria and are not already addressed  .
elsewhere. These pesticides are listed in
Tables.
TABLE  3.— PESTICIDES  SELECTED
  THE 1991 DWPL BASED ON THEIR PO-
  TENTIAL TO LEACH IN GROUND WATER

Asulam
Bromaca
Cyromazino
Fomesafen
Lactofen/AcHluorfen
Metalaxyt
Methomyl                  •
Thiodicarb  •                '  '
 3. Substances Recommended by States
 and EPA Regions

   With the assistance of the Federal-
 State Toxicology and Regulatory
 Alliance Committee (FSTRAC), EPA
 solicited recommendations from the ..
 States and EPA regions for high-priority
 drinking water contaminants which..
 should be considered for inclusion in the
 1991 DWPL. FSTRAC consists of  .
 representatives from State and Federal  .
 drinking water programs brought
 together to exchange ideas and
 information on the toxicology and risk
 assessment of drinking water
 contaminants. FSTRAC surveyed the
 drinking waterprograms in all 50 States
 and Puerto Rico for recommendations
 regarding chemicals for future standards
 development by EPA. FSTRAC
 identified the chemicals most frequently
 requested for regulation (i.e., requested
 by four or more States). The. reasons for
 requested standards development for .
 these chemicals included their
 widespread .use, documented or
 suspected adverse.human health effects,.
 and/or prevalence in .drinking water. •.  ,
 Many States and EPA regions also -  -  .
, submitted recommendations directly to
'. the .EPA. Based on 'the recommendations
.of .the States and EPA regions, the ...
 chemicals listed in Table-4 have been
 -selected for the 1991 DWPL:      :

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                    •'. Federal  Register '/ Vol. ~56,  No. Si / Monday, January  14,  1991  / Notices
                                                                            1473
TABLE 4.—SUBSTANCES SELECTED  FOR
  THE 1991  DWPL BASED ON THE REC-
  OMMENDATION OF STATES  AND EPA
  REGIONS

Manganese        "             .   "
Methyl ethyl ketone
Methyl (sobutyl ketone
Tetrahydrofuran
ID. 1991 Version of the Drinking Water
Priority List

  Table 5 shows the final 1991 Drinking
Water Priority List of contaminants/
contaminant groups. The list is
comprised of 50 contaminants/
contaminant groups from the 1988 list
(which continue to meet the DWPL
criteria and have not been regulated
thus far) and 27 new substances
selected from the four groups discussed
in this notice. The total number of
contaminants/contaminant groups on
the revised list is 77.

TABLE 5.—PRIORITY LIST (1991  VERSION)
  OF CONTAMINANTS WHICH  MAY  RE-
  QUIRE REGULATION UNDER THE SAFE
  DRINKING WATER ACT
TABLE 5.—PRIORITY LIST (1991 VERSION)
  OF CONTAMINANTS (WHICH  MAY RE-
  QUIRE .REGULATION .UNDER THE  SAFE
  DRINKING WATER ACT—Continued
Substance
Inorganics (Total number =
14)
Aluminum 	 	 	
Boron................. 	 ...........
Chloramines..H..«...H..«.»..........
Chlorate ........
Chlorine. ..................................
Chlorine dioxide 	 ..
Chlorite 	 	 	 ......
Cyanogen chloride 	
Hypochlorite ton..... 	 .....
Manganese 	
Molybdenum.......... 	 . 	 .....
Strontium...™..................,,........
Vanadium ...»........»....„...«„„..•..
Zinc 	 „.„....„.„„...•.„...._......„„
Pesticides (Total number =
19)
Asulam 	 ........ — .._..
Bentazon 	 	 	 	 	
Bromacil ..«.«....«.«..»«.»»«.......
Cyanazine 	 _..._ 	 ......
Cyromazine...»..........................
DCPA (and its acid metabo-
lites).....-.... 	
Dicamba...«..... H
Ethylenethiourea ._ 	
Fomesafen 	
Lactofen/Aciiluorfen 	
Metalaxyl 	 „ 	 . 	
Methomyl 	
metolachlor..-..-...™.....-... 	
Metribuzln ........ 	 „..„ 	
Parathion degradation prod-
, uct (4-Nitrophenol) — 	
Prometon ..................... 	 «
2,4,5-T 	 ...................... 	 '. 	 ..
Thbdicarb 	 .„ 	 ...
Trifluralin . .......... .. „._. .
Synthetic Organic Ote/nfcals
(Total number -= 43)
' Acrylonitrile 	 ™_ 	 _..^..
: Bromobenzene..^«.«.-..u»».
CAS No.


7429905
7440428
».».........««.... 	
14866683
7782505
10049044
14998277
506774
14380611
7439965
7439987
7440246
7440622
7440666


3337711
25057890
314409
21725462
66215278

1861321
1918009
96457
72178020
77501634/5094666
57837191
16752775
. 51218452
21807649

100027
1610180
93765
' 59669260
1582098


107131
i 108861
        Substance
  Bromochloroacetonitrila —...
  Bromodtehloromethane	—
  Bromoform	,..._.....	_.
  Bromo methane	
  Chlorination/Chlorami nation
   by-products (Misc.), e.g.,
   Haloacetic acids, Haloke-
   tones,  Chloral  hydrate,
   MX-2 [3-chloro-4-(dichlor-.
   omethyl)-5-hydroxy-2
   (SHMuranonel, N-Organ-
   ochloramines	
  Chlofoethane.H»...».H.»	«....
  Chloroform—	_...:...„
  Chloromethane	...—
  Chloropicrin—„....._	
  o-Chlorotoluene.......................
  p-CWorotoluene—		.'..
  DibromoacetonHrile	
  Dibromochloromethane	
  Dibromomethane	......
  Dichloroacetonitrite	
  1,3-Dichlorobenzene	.........
  Dichlorodifluoro methane	
  1,1-Dichloroetnane	
  2,2-Dichloropropane.._....
  1,3-Dichloropropane	
  1,1-Dichloropropene	
  1,3-Dichloropropene ........
  2,4-Dinitrophenol	
  2,4-Dinitrotoluene	
  2,6-Dinitrototuene.....	
 . 1,2-Diphenylhydrazine	
  Fluorotrichloromethane	
  Hexachlorobutadiene...—.....
  Hexachloroe thane	
  Isophorone	
  Methyl ethyl ketone	
  Methyl isobutyl ketone	
  MethyM-butyl ether	
  Naphthalene............................
  Nitrobenzene...........................
  Ozone by-products, e.g., Al-
   dehydes, Epoxides, Per-
   oxides, Nitrosamines, Bro-
   mate, lodate
  1,1,1,2-Tetrachloroethane	
  1,1 ^,2-Tetrachloroethane	
  Tetrahydrofuran«	...............
  Trtohloroacetonitrile.......	
  1,2,3-Trichloropropane	
Microorganisms (Total number
  -1)
  Cryptosporidum
                             CAS No.
83463621
   75274
   75252
   74839
   75003
   67663
   74873
   76062
   95498
  106434
 3252435
  124481
   74953
 3018120
  541731
   75718
   75343
  594207
  142289
  563586
  542756
   51285
  121142
  606202
  122667
   75694
   87683
   67721
   78591
   78933
  108101
 1634044
   91203
   98953
                                                                            630206
                                                                             79345
                                                                            109999
                                                                            545062
                                                                             96184
                                          IV. Future Revisions of the Drinking
                                          Water Priority List

                                             In accordance with the requirements
                                          of the SDWA, EPA will revise the DWPL
                                          every three years. Revisions will drop
                                          those contaminants for which
                                          regulations have been promulgated, and
                                          add new contaminants which may be of
                                          concern. Revisions will also drop
                                          contaminants which no longer meet
                                          EPA's established criteria for
                                          contaminant selection. EPA welcomes.
                                          public comments or any suggestions for
                                          future revisions of the list.
 V. Other Requirements

 A. Executive Order 12291

   Under Executive Ordet 12291, EPA'
 must judge whether a regulation is
 "major" and therefore subject to the
 requirements of a Regulatory Impact
 Analysis. This notice is not a regulation
 and will not have a financial or
 economic impact on any party.
 Therefore, EPA has not prepared an
 Economic Impact Analysis (EIA). EPA
 will prepare an EIA, if appropriate, at
 the time of regulation of any
 contaminant on the DWPL

 B. Regulatory Flexibility Act

   The Regulatory Flexibility Act (5
 U.S.C. 601, et seq.) requires EPA to
 explicitly consider the effect of proposed
 regulations  on small entities. This notice
 does not constitute a proposed
 rulemaking activity. Therefore, the
 Regulatory Flexibility Act requires no
 such analysis. As EPA prepares
 regulations  for contaminants selected
 from the Drinking Water Priority List
 under section 1412 of the SDWA, EPA
 will consider the effect of the proposed
 regulations  on small entities.

 C. Paperwork Reduction Act

   There are no information collection
 requirements in this notice (44 U.S.C.
 3501 et seq.).

 VI. References

   References for the revised DWPL are
 included in the public docket for this
 notice. This docket is located at EPA
 Headquarters, at the address listed at
 the beginning of this notice. Individuals
, should contact the docket clerk (202-
 382-3027) for access to the public
 docket. Materials for the revised DWPL
 are as follows:
   FSTRAC, "States' Needs for Chemicals for
 Regulation in Drinking Waters," Hutcheson
 to Hais, April 27,1990.
   State of California, "Chemicals for
 Inclusion on the Candidate List for
 Regulation Under the Safe Drinking Water
 Act," Fan to Cantilli, May 2.1990.
   State of Illinois, "List of Compounds Which
 Have Been Detected in Public Water Supplies
 and at Cleanup Sites," Virgin to Cantilli,
 April 30,1990.
   State of Maryland,  "List of Drinking Water
 Contaminants Which Have Occurred in
 Private or Public Water Systems in
 Maryland," Paull to Saxena, April 19,1990.
   State of Rhode Island, "Candidate
 Substances for Safe Drinking Water Act List
 of Priority Drinking Water Contaminants,"
 Lee to Cantilli, May 10,1990..
   State of Wisconsin, "Substances for
 Inclusion on the Drinking Water Priority.
 List," Swailes to Saxena. April 16,1990.
  . U.S. EPA, "National Primary Drinking
 Water Regulations: Synthetic Organic

-------
 1474
Federal Register  / VoL 58,  No.  9 / Monday. January  14,  1991  / Notices
 Chemicals, Inorganic Chemicals and
 Microorganisms: Proposed Rule" (50 FR
^0030. November 13.1805).
   VS. EPA. "Notice of the First Priority List
 of Hazardous Substances that Will Be the
 Subject of Toxicological Profiles and
 Guideline! for Development of Toxicological
 Profile*," {SZ FR 12868. April 17.1967].
   US.EPA, "List of National Pesticide
 Survey Anslytci" and "Preliminary Survey
 Results," National Pesticide Survey File 1987-
 leoo.
   VS. EPA, "Drinking Water Substitution of
.Contaminants and Drinking Water Priority
                     List of Additional Substances .Which May
                     Require Regulation Under the Safe Drinking
                     Water Act" (53 FR 1892, January 22,1988),
                      . U:S. EP£ "Hazardous Substances Priority
                     • List/Toxicolqgical Profiles; Second List {53
                     FR 41280. October 20,1988).
                       U.S. EPA, Toxies-Release.Inventory
                     (TRI)." National Report 1988. Draft.
                     •  U.S. EPA. "National Primary and
                     Secondary Drinking Water Regulation;
                     Proposed Rule" (54 FR 22062, May 22,1969).
                       U.S. EPA, "The Third List of Hazardous
                     Substances That-Will Be the Subject of
Toxicological Profiles {54 FR 43815. October
26,1989).
  US. EPA. Region t "Drinking Water
Priority List (DWPL) for 1991-^-tisling of   '
Candidates for Regulation." Chow to CantilH.
May 15,1990.
  Dated: December 31,1990.
F. Henry Habicht,
Acting Administrator.
[FR Doc. 91-808 Filed 1-11-918:45 am]
BILLING CODE (580-SO-U

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