EPA

United States

Environmental Protection

Agency

Office of Water

4304

EPA 822-Z-99-001

April 1999

National Recommended

Water Quality Criteria–

Correction
1

SUMMARY: EPA is publishing a compilation of its national recommended water quality criteria

for 157 pollutants, developed pursuant to section 304(a) of the Clean Water Act (CWA or the

Act). These recommended criteria provide guidance for States and Tribes in adopting water

quality standards under section 303(c) of the CWA. Such standards are used in implementing a

number of environmental programs, including setting discharge limits in National Pollutant

Discharge Elimination System (NPDES) permits. These water quality criteria are not regulations,

and do not impose legally binding requirements on EPA, States, Tribes or the public. 

This notice also describes changes in EPA’s process for deriving new and revised 304(a)

criteria. Comments provided to the Agency about the content of this Notice will be considered in

future publications of water quality criteria and in carrying out the process for deriving water

quality criteria. With this improved process the public will have more opportunity to provide data

and views for consideration by EPA. The public may send any comments or observations

regarding the compilation format or the process for deriving new or revised water quality criteria

to the Agency now, or anytime while the process is being implemented. 

ADDRESSES: A copy of the notice, "National Recommended Water Quality Criteria" is

available from the U.S. EPA, National Center for Environmental Publications and Information,

11029 Kenwood Road, Cincinnati, Ohio, 45242, phone (513) 489-8190. The publication is also

available electronically at: http://www.epa.gov/ost. Send an original and 3 copies of written

comments to W-98-24 Comment Clerk, Water Docket, MC 4104, US EPA, 401 M Street, S.W.,

Washington, D.C. 20460. Comments may also be submitted electronically to OWDocket@epamail.epa.gov. Comments should be submitted as a WP5.1, 6.1 or an ASCII file with

no form of encryption. The documents cited in the compilation of recommended criteria are

available for inspection from 9:00 to 4:00 p.m., Monday through Friday, excluding legal holidays,

at the Water Docket, EB57, East Tower Basement, USEPA, 401 M St., S.W., Washington, D.C.,

20460. For access to these materials, please call (202) 260-3027 to schedule an appointment.

FOR FURTHER INFORMATION CONTACT: Cindy A. Roberts, Health and Ecological

Criteria Division (4304), U.S. EPA, 401 M. Street, S.W., Washington, D.C., 20460; (202) 260-2787;

roberts.cindy@epamail.epa.gov.

SUPPLEMENTARY INFORMATION:

I. What are Water Quality Criteria?

Section 304(a)(1) of the Clean Water Act requires EPA to develop and publish, and from

time to time revise, criteria for water quality accurately reflecting the latest scientific knowledge. 

Water quality criteria developed under section 304(a) are based solely on data and scientific

judgments on the relationship between pollutant concentrations and environmental and human

health effects. Section 304(a) criteria do not reflect consideration of economic impacts or the

technological feasibility of meeting the chemical concentrations in ambient water. Section 304(a)

criteria provide guidance to States and Tribes in adopting water quality standards that ultimately

provide a basis for controlling discharges or releases of pollutants. The criteria also provide
2

guidance to EPA when promulgating federal regulations under section 303(c) when such action is

necessary.

II. What is in the Compilation Published Today?

EPA is today publishing a compilation of its national recommended water quality criteria for 157

pollutants. This compilation is also available in hard copy at the address given above. 

The compilation is presented as a summary table containing EPA’s water quality criteria

for 147 pollutants, and for an additional 10 pollutants, criteria solely for organoleptic effects. For

each set of criteria, EPA lists a Federal Register citation, EPA document number or Integrated

Risk Information System (IRIS) entry (www.epa.gov/ngispgm3/iris/irisdat). Specific information

pertinent to the derivation of individual criteria may be found in cited references. If no criteria are

listed for a pollutant, EPA does not have any national recommended water quality criteria. 

These water quality criteria are the Agency’s current recommended 304(a) criteria,

reflecting the latest scientific knowledge. They are generally applicable to the waters of the

United States. EPA recommends that States and Tribes use these water quality criteria as

guidance in adopting water quality standards pursuant to section 303(c) of the Act and the

implementing federal regulations at 40 CFR 131. Water quality criteria derived to address sitespecific situations are not included; EPA recommends that States and Tribes follow EPA's

technical guidance in the "Water Quality Standards Handbook - 2nd Edition," EPA, August 1994,

in deriving such site-specific criteria. EPA recognizes that in limited circumstances there may be

regulatory voids in the absence of State or Tribal water quality standards for specific pollutants. 

However, States and Tribes should utilize the existing State and Tribal narrative criteria to

address such situations; States and Tribes may consult EPA criteria documents and cites in the

summary table for additional information.

The national recommended water quality criteria include: previously published criteria that

are unchanged; criteria that have been recalculated from earlier criteria; and newly calculated

criteria, based on peer-reviewed assessments, methodologies and data, that have not been

previously published.

The information used to calculate the water quality criteria is not included in the summary

table. Most information has been previously published by the Agency in a variety of sources, and

the summary table cites those sources.

When using these 304(a) criteria as guidance in adopting water quality standards, EPA

recommends States and Tribes consult the citations referenced in the summary table for additional

information regarding the derivation of individual criteria.

The Agency intends to revise the compilation of national recommended water quality

criteria from time to time to keep States and Tribes informed as to the most current recommended

water quality criteria.
3

III. How Are National Recommended Water Quality Criteria Used?

Once new or revised 304(a) criteria are published by EPA, the Agency expects States and

Tribes to adopt promptly new or revised numeric water quality criteria into their standards

consistent with one of the three options in 40 CFR 131.11. These options are: (1) adopt the

recommended section 304(a) criteria; (2) adopt section 304(a) criteria modified to reflect sitespecific conditions; or, (3) adopt criteria derived using other scientifically defensible methods. 

In adopting criteria under option (2) or (3), States and Tribes must adopt water quality criteria

sufficient to protect the designated uses of their waters. When establishing a numerical value

based on 304(a) criteria, States and Tribes may reflect site specific conditions or use other

scientifically defensible methods. However, States and Tribes should not selectively apply data or

selectively use endpoints, species, risk levels, or exposure parameters in deriving criteria; this

would not accurately characterize risk and would not result in criteria protective of designated

uses.

 EPA emphasizes that, in the course of carrying out its responsibilities under section

303(c), it reviews State and Tribal water quality standards to assess the need for new or revised

water quality criteria. EPA generally believes that five years from the date of EPA’s publication

of new or revised water quality criteria is a reasonable time by which States and Tribes should

take action to adopt new or revised water quality criteria necessary to protect the designated uses

of their waters. This period is intended to accommodate those States and Tribes that have begun

a triennial review and wish to complete the actions they have underway, deferring initiating

adoption of new or revised section 304(a) criteria until the next triennial review. 

IV. What is the Status of Existing Criteria While They Are Under Revision? 

The question of the status of the existing section 304(a) criteria often arises when EPA

announces that it is beginning a reassessment of existing criteria. The general answer is that water

quality criteria published by EPA remain the Agency’s recommended water quality criteria until

EPA revises or withdraws the criteria. For example, while undertaking recent reassessments of

dioxin, PCBs, and other chemicals, EPA has consistently upheld the use of the current section

304(a) criteria for these chemicals and considers them to be scientifically sound until new, peer

reviewed, scientific assessments indicate changes are needed. Therefore, the criteria in today’s

notice are and will continue to be the Agency’s national recommended water quality criteria for

States and Tribes to use in adopting or revising their water quality standards until superseded by

the publication of revised criteria, or withdrawn by notice in the Federal Register.

V. What is the Process for Developing New or Revised Criteria?

Section 304(a)(1) of the CWA requires the Agency to develop and publish, and from time

to time revise, criteria for water quality accurately reflecting the latest scientific knowledge. The

Agency has developed an improved process that it intends to use when deriving new criteria or

conducting a major reassessment of existing criteria. The purpose of the improved process is to
4

provide expanded opportunities for public input, and to make the process more efficient.

When deriving new criteria, or when initiating a major reassessment of existing criteria,

EPA will take the following steps.

1. EPA will first undertake a comprehensive review of available data and information.

2. EPA will publish a notice in the Federal Register and on the Internet announcing its

assessment or reassessment of the pollutant. The notice will describe the data available to the

Agency, and will solicit any additional pertinent data or views that may be useful in deriving new

or revised criteria. EPA is especially interested in hearing from the public regarding new data or

information that was unavailable to the Agency, and scientific views as to the application of the

relevant Agency methodology for deriving water quality criteria.

3. After public input is received and evaluated, EPA will then utilize information obtained

from both the Agency’s literature review and the public to develop draft recommended water

quality criteria.

4. EPA will initiate a peer review of the draft criteria. Agency peer review consists of a

documented critical review by qualified independent experts. Information about EPA peer review

practices may be found in the Science Policy Council’s Peer Review Handbook (EPA 100-B-98-

001, www.epa.gov).

5. Concurrent with the peer review in step four, EPA will publish a notice in the Federal

Register and on the Internet, of the availability of the draft water quality criteria and solicit views

from the public on issues of science pertaining to the information used in deriving the draft

criteria. The Agency believes it is important to provide the public with the opportunity to provide

scientific views on the draft criteria even though we are not required to invite and respond to

written comments.

6. EPA will evaluate the results of the peer review, and prepare a response document for

the record in accordance with EPA's Peer Review Handbook. EPA at the same time will consider

views provided by the public on issues of science. Major scientific issues will be addressed in the

record whether from the peer review or the public.

7. EPA will then revise the draft criteria as necessary, and announce the availability of the

final water quality criteria in the Federal Register and on the Internet.

VI. What is the Process for Minor Revisions to Criteria?

In addition to developing new criteria, and conducting major reassessments of existing

criteria, EPA also from time to time recalculates criteria based on new information pertaining to

individual components of the criteria. For example, in today’s notice, EPA has recalculated a

number of criteria based on new, peer-reviewed data contained in EPA's IRIS. Because such
5

recalculations normally result in only minor changes to the criteria, do not ordinarily involve a

change in the underlying scientific methodologies, and reflect peer-reviewed data, EPA will

typically publish such recalculated criteria directly as the Agency’s recommended water quality

criteria. If it appears that a recalculation results in a significant change EPA will follow the

process of peer review and public input outlined above. Further, when EPA recalculates national

water quality criteria in the course of proposing or promulgating state-specific federal water

quality standards pursuant to section 303(c), EPA will offer an opportunity for national public

input on the recalculated criteria.

VII. How Does the Process Outlined Above Improve Public Input and Efficiency?

In the past, EPA developed draft criteria documents and announced their availability for

public comment in the Federal Register. This led to new data and views coming to EPA’s

attention after draft criteria had already been developed. Responding to new data would

sometimes lead to extensive revisions.

The steps outlined above improve the criteria development process in the following ways.

1. The new process is Internet-based which is in line with EPA policy for public access

and dissemination of information gathered by EPA. Use of the Internet will allow the public to be

more engaged in the criteria development process than previously and to more knowledgeably

follow criteria development. For new criteria or major revisions, EPA will announce its intentions

to derive the new or revised criteria on the Internet and include a list of the available literature. 

This will give the public an opportunity to provide additional data that might not otherwise be

identified by the Agency.

 2. The public now has two opportunities to contribute data and views, before

development and during development, instead of a single opportunity after development. 

3. EPA has instituted broader and more formal peer review procedures. This independent

scientific review is a more rigorous disciplinary practice to ensure technical improvements in

Agency decision making. Previously, EPA used the public comment process outlined above to

obtain peer review. The new process allows for both public input and a formal peer review,

resulting in a more thorough and complete evaluation of the criteria.

 4. Announcing the availability of the draft water quality criteria on the Internet will give

the public an opportunity to provide input on issues of science in a more timely manner.

VIII. Where Can I Find More Information About Water Quality Criteria and 

Water Quality Standards?

For more information about water quality criteria and Water Quality Standards refer to the

following: Water Quality Standards Handbook (EPA 823-B94-005a); Advanced Notice of

Proposed Rule Making (ANPRM), (63FR36742); Water Quality Criteria and Standards Plan --
6

Priorities for the Future (EPA 822-R-98-003); Guidelines and Methodologies Used in the

Preparation of Health Effects Assessment Chapters of the Consent Decree Water Criteria

Documents (45FR79347); Draft Water Quality Criteria Methodology Revisions: Human Health

(63FR43755, EPA 822-Z-98-001); and Guidelines for Deriving Numerical National Water

Quality Criteria for the Protection of Aquatic Organisms and Their Uses (EPA 822/R-85-100);

National Strategy for the Development of Regional Nutrient Criteria (EPA 822-R-98-002).

These publications may also be accessed through EPA’s National Center for

Environmental Publications and Information (NCEPI) or on the Office of Science and

Technology’s Home-page (www.epa.gov/OST).

IX. What Are the National Recommended Water Quality Criteria?

The following compilation and its associated footnotes and notes presents the national

recommended water quality criteria.
 NATIONAL RECOMMENDED WATER QUALITY CRITERIA FOR PRIORITY TOXIC POLLUTANTS

7

Priority Pollutant

CAS

Number

Freshwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Human Health

 For Consumption of:

Water + Organism 

 Organism Only

 (Fg/L) (Fg/L)

FR Cite/

Source

1 Antimony 7440360 14 B,Z 4300 B 57FR60848

2 Arsenic 7440382 340 A,D,K 150 A,D,K 69 A,D,bb 36 A,D,bb

0.018 C,M,S 0.14 C,M,S

62FR42160

57FR60848

3 Beryllium 7440417 J,Z J 62FR42160

4 Cadmium 7440439 4.3 D,E,K 2.2 D,E,K 42 D,bb 9.3 D,bb J,Z J 62FR42160

5a Chromium III 16065831 570 D,E,K 74 D,E,K

J,Z Total J

EPA820/B-96-001

62FR42160

5b Chromium VI 18540299 16 D,K 11 D,K 1,100 D,bb 50 D,bb J, Z Total J 62FR42160

6 Copper 7440508 13 D,E,K,cc 9.0 D,E,K,cc 4.8 D,cc,ff 3.1 D,cc,ff 1,300 U 62FR42160

7 Lead 7439921 65 D,E,bb,gg 2.5 D,E,bb,gg 210 D,bb 8.1 D,bb J J 62FR42160

8 Mercury 7439976 1.4 D,K,hh 0.77 D,K,hh 1.8 D,ee,hh 0.94 D,ee,hh 0.050 B 0.051 B 62FR42160

9 Nickel 7440020 470 D,E,K 52 D,E,K 74 D,bb 8.2 D,bb 610 B 4,600 B 62FR42160

10 Selenium 7782492 L,R,T 5.0 T 290 D,bb,dd 71 D,bb,dd

170 Z 11,000 

62FR42160

IRIS 09/01/91

11 Silver 7440224 3.4 D,E,G 1.9 D,G 62FR42160

12 Thallium 7440280 1.7 B 6.3 B 57FR60848

13 Zinc 7440666 120 D,E,K 120 D,E,K 90 D,bb 81 D,bb

9,100 U 69,000 U

62FR42160

IRIS 10/01/92
Priority Pollutant

CAS

Number

Freshwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Human Health

 For Consumption of:

Water + Organism 

 Organism Only

 (Fg/L) (Fg/L)

FR Cite/

Source

8

14 Cyanide 57125 22 K,Q 5.2 K,Q

1 Q,bb 1 Q,bb 700 B,Z 220,000 B,H

EPA820/B-96-001

57FR60848

15 Asbestos 1332214 7 million

fibers/L I

57FR60848

16 2,3,7,8-TCDD Dioxin 1746016 1.3E-8 C 1.4E-8 C 62FR42160

17 Acrolein 107028 320 780 57FR60848

18 Acrylonitrile 107131 0.059 B,C 0.66 B,C 57FR60848

19 Benzene 71432 1.2 B,C 71 B,C 62FR42160

20 Bromoform 75252 4.3 B,C 360 B,C 62FR42160

21 Carbon Tetrachloride 56235 0.25 B,C 4.4 B,C 57FR60848

22 Chlorobenzene 108907 680 B,Z 21,000 B,H 57FR60848

23 Chlorodibromomethane 124481 0.41 B,C 34 B,C 62FR42160

24 Chloroethane 75003

25 2-Chloroethylvinyl Ether 110758

26 Chloroform 67663 5.7 B,C 470 B,C 62FR42160

27 Dichlorobromomethane 75274 0.56 B,C 46 B,C 62FR42160

28 1,1-Dichloroethane 75343

29 1,2-Dichloroethane 107062 0.38 B,C 99 B,C 57FR60848

30 1,1-Dichloroethylene 75354 0.057 B,C 3.2 B,C 57FR60848
Priority Pollutant

CAS

Number

Freshwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Human Health

 For Consumption of:

Water + Organism 

 Organism Only

 (Fg/L) (Fg/L)

FR Cite/

Source

9

31 1,2-Dichloropropane 78875 0.52 B,C 39 B,C 62FR42160

32 1,3-Dichloropropene 542756 10 B 1,700 B 57FR60848

33 Ethylbenzene 100414 3,100 B,Z 29,000 B 62FR42160

34 Methyl Bromide 74839 48 B 4000 B 62FR42160

35 Methyl Chloride 74873 J J 62FR42160

36 Methylene Chloride 75092 4.7 B,C 1600 B,C 62FR42160

37 1,1,2,2-Tetrachloroethane 79345 0.17 B,C 11 B,C 57FR60848

38 Tetrachloroethylene 127184 0.8 C 8.85 C 57FR60848

39 Toluene 108883 6,800 B,Z 200,000 B 62FR42160

40 1,2-Trans-Dichloroethylene 156605 700 B,Z 140,000 B 62FR42160

41 1,1,1-Trichloroethane 71556 J,Z J 62FR42160

42 1,1,2-Trichloroethane 79005 0.60 B,C 42 B,C 57FR60848

43 Trichloroethylene 79016 2.7 C 81 C 57FR60848

44 Vinyl Chloride 75014 2.0 C 525 C 57FR60848

45 2-Chlorophenol 95578 120 B,U 400 B,U 62FR42160

46 2,4-Dichlorophenol 120832 93 B,U 790 B,U 57FR60848

47 2,4-Dimethylphenol 105679 540 B,U 2,300 B,U 62FR42160

48 2-Methyl-4,6-Dinitrophenol 534521 13.4 765 57FR60848

49 2,4-Dinitrophenol 51285 70 B 14,000 B 57FR60848

50 2-Nitrophenol 88755

51 4-Nitrophenol 100027

52 3-Methyl-4-Chlorophenol 59507 U U
Priority Pollutant

CAS

Number

Freshwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Human Health

 For Consumption of:

Water + Organism 

 Organism Only

 (Fg/L) (Fg/L)

FR Cite/

Source

10

53 Pentachlorophenol 87865 19 F,K 15 F,K 13 bb 7.9 bb 0.28 B,C 8.2 B,C,H 62FR42160

54 Phenol 108952 21,000 B,U

4,600,000 B,H,U

62FR42160

57FR60848

55 2,4,6-Trichlorophenol 88062 2.1 B,C,U 6.5 B,C 62FR42160

56 Acenaphthene 83329 1,200 B,U 2,700 B,U 62FR42160

57 Acenaphthylene 208968

58 Anthracene 120127 9,600 B 110,000 B 62FR42160

59 Benzidine 92875 0.00012 B,C 0.00054 B,C 57FR60848

60 BenzoaAnthracene 56553 0.0044 B,C 0.049 B,C 62FR42160

61 BenzoaPyrene 50328 0.0044 B,C 0.049 B,C 62FR42160

62 BenzobFluoranthene 205992 0.0044 B,C 0.049 B,C 62FR42160

63 BenzoghiPerylene 191242

64 BenzokFluoranthene 207089 0.0044 B,C 0.049 B,C 62FR42160

65 Bis2-ChloroethoxyMethane 111911

66 Bis2-ChloroethylEther 111444 0.031 B,C 1.4 B,C 57FR60848

67 Bis2-ChloroisopropylEther 39638329 1,400 B

170,000 B

62FR42160

57FR60848

68 Bis2-EthylhexylPhthalateX117817 1.8 B,C 5.9 B,C 57FR60848

69 4-Bromophenyl Phenyl

Ether

101553

70 Butylbenzyl PhthalateW 85687 3,000 B 5,200 B 62FR42160

71 2-Chloronaphthalene 91587 1,700 B 4,300 B 62FR42160
Priority Pollutant

CAS

Number

Freshwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Human Health

 For Consumption of:

Water + Organism 

 Organism Only

 (Fg/L) (Fg/L)

FR Cite/

Source

11

72 4-Chlorophenyl Phenyl

Ether

7005723

73 Chrysene 218019 0.0044 B,C 0.049 B,C 62FR42160

74 Dibenzoa,hAnthracene 53703 0.0044 B,C 0.049 B,C 62FR42160

75 1,2-Dichlorobenzene 95501 2,700 B,Z 17,000 B 62FR42160

76 1,3-Dichlorobenzene 541731 400 2,600 62FR42160

77 1,4-Dichlorobenzene 106467 400 Z 2600 62FR42160

78 3,3'-Dichlorobenzidine 91941 0.04 B,C 0.077 B,C 57FR60848

79 Diethyl PhthalateW 84662 23,000 B 120,000 B 57FR60848

80 Dimethyl PhthalateW 131113 313,000 2,900,000 57FR60848

81 Di-n-Butyl PhthalateW 84742 2,700 B 12,000 B 57FR60848

82 2,4-Dinitrotoluene 121142 0.11 C 9.1 C 57FR60848

83 2,6-Dinitrotoluene 606202

84 Di-n-Octyl Phthalate 117840

85 1,2-Diphenylhydrazine 122667 0.040 B,C 0.54 B,C 57FR60848

86 Fluoranthene 206440 300 B 370 B 62FR42160

87 Fluorene 86737 1,300 B 14,000 B 62FR42160

88 Hexachlorobenzene 118741 0.00075 B,C 0.00077 B,C 62FR42160

89 Hexachlorobutadiene 87683 0.44 B,C 50 B,C 57FR60848

90 Hexachlorocyclopentadiene 77474 240 B,U,Z 17,000 B,H,U 57FR60848

91 Hexachloroethane 67721 1.9 B,C 8.9 B,C 57FR60848
Priority Pollutant

CAS

Number

Freshwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Human Health

 For Consumption of:

Water + Organism 

 Organism Only

 (Fg/L) (Fg/L)

FR Cite/

Source

12

92 Ideno1,2,3-cdPyrene 193395 0.0044 B,C 0.049 B,C 62FR42160

93 Isophorone 78591 36 B,C 2,600 B,C IRIS

11/01/97 

94 Naphthalene 91203

95 Nitrobenzene 98953 17 B 1,900 B,H,U 57FR60848

96 N-Nitrosodimethylamine 62759 0.00069 B,C 8.1 B,C 57FR60848

97 N-Nitrosodi-n-Propylamine 621647 0.005 B,C 1.4 B,C 62FR42160

98 N-Nitrosodiphenylamine 86306 5.0 B,C 16 B,C 57FR60848

99 Phenanthrene 85018

100 Pyrene 129000 960 B 11,000 B 62FR42160

101 1,2,4-Trichlorobenzene 120821 260 Z 940 IRIS 11/01/96

102 Aldrin 309002 3.0 G 1.3 G 0.00013 B,C 0.00014 B,C 62FR42160

103 alpha-BHC 319846 0.0039 B,C 0.013 B,C 62FR42160

104 beta-BHC 319857 0.014 B,C 0.046 B,C 62FR42160

105 gamma-BHC (Lindane) 58899 0.95 K 0.16 G 0.019 C 0.063 C 62FR42160

106 delta-BHC 319868

107 Chlordane 57749 2.4 G 0.0043 G,aa 0.09 G 0.004 G,aa

0.0021 B,C 0.0022 B,C

62FR42160

IRIS02/07/98

108 4,4'-DDT 50293 1.1 G 0.001 G,aa 0.13 G 0.001 G,aa 0.00059 B,C 0.00059 B,C 62FR42160

109 4,4'-DDE 72559 0.00059 B,C 0.00059 B,C 62FR42160

110 4,4'-DDD 72548 0.00083 B,C 0.00084 B,C 62FR42160
Priority Pollutant

CAS

Number

Freshwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

 (Fg/L) (Fg/L) 

 Human Health

 For Consumption of:

Water + Organism 

 Organism Only

 (Fg/L) (Fg/L)

FR Cite/

Source

13

111 Dieldrin 60571 0.24 K 0.056 K,O 0.71 G 0.0019 G,aa 0.00014 B,C 0.00014 B,C 62FR42160

112 alpha-Endosulfan 959988 0.22 G,Y 0.056 G,Y 0.034 G,Y 0.0087 G,Y 110 B 240 B 62FR42160

113 beta-Endosulfan 33213659 0.22 G,Y 0.056 G,Y 0.034 G,Y 0.0087 G,Y 110 B 240 B 62FR42160

114 Endosulfan Sulfate 1031078 110 B 240 B 62FR42160

115 Endrin 72208 0.086 K 0.036 K,O 0.037 G 0.0023 G,aa 0.76 B 0.81 B,H 62FR42160

116 Endrin Aldehyde 7421934 0.76 B 0.81 B,H 62FR42160

117 Heptachlor 76448 0.52 G 0.0038 G,aa 0.053 G 0.0036 G,aa 0.00021 B,C 0.00021 B,C 62FR42160

118 Heptachlor Epoxide 1024573 0.52 G,V 0.0038 G,V,aa 0.053 G,V 0.0036 G,V,aa 0.00010 B,C 0.00011 B,C 62FR42160

119 Polychlorinated Biphenyls

PCBs:

0.014 N,aa 0.03 N,aa

0.00017 B,C,P 0.00017 B,C,P

62FR42160

63FR16182

120 Toxaphene 8001352 0.73 0.0002 aa 0.21 0.0002 aa 0.00073 B,C 0.00075 B,C 62FR42160

Footnotes:

A This recommended water quality criterion was derived from data for arsenic (III), but is applied here to total arsenic, which might imply that arsenic (III) and

arsenic (V) are equally toxic to aquatic life and that their toxicities are additive. In the arsenic criteria document (EPA 440/5-84-033, January 1985), Species

Mean Acute Values are given for both arsenic (III) and arsenic (V) for five species and the ratios of the SMAVs for each species range from 0.6 to 1.7. Chronic

values are available for both arsenic (III) and arsenic (V) for one species; for the fathead minnow, the chronic value for arsenic (V) is 0.29 times the chronic value

for arsenic (III). No data are known to be available concerning whether the toxicities of the forms of arsenic to aquatic organisms are additive.

B This criterion has been revised to reflect The Environmental Protection Agency’s q1* or RfD, as contained in the Integrated Risk Information System (IRIS) as of 

 April 8, 1998. The fish tissue bioconcentration factor (BCF) from the 1980 Ambient Water Quality Criteria document was retained in each case.

C This criterion is based on carcinogenicity of 10-6 risk. Alternate risk levels may be obtained by moving the decimal point (e.g., for a risk level of 10-5, move 

the decimal point in the recommended criterion one place to the right).

D Freshwater and saltwater criteria for metals are expressed in terms of the dissolved metal in the water column. The recommended water quality criteria 

value was calculated by using the previous 304(a) aquatic life criteria expressed in terms of total recoverable metal, and multiplying it by a conversion factor 

(CF). The term "Conversion Factor" (CF) represents the recommended conversion factor for converting a metal criterion expressed as the total recoverable

fraction in the water column to a criterion expressed as the dissolved fraction in the water column. (Conversion Factors for saltwater CCCs are not currently

available. Conversion factors derived for saltwater CMCs have been used for both saltwater CMCs and CCCs). See "Office of Water Policy and Technical
14

Guidance on Interpretation and Implementation of Aquatic Life Metals Criteria,” October 1, 1993, by Martha G. Prothro, Acting Assistant Administrator for

Water, available from the Water Resource center, USEPA, 401 M St., SW, mail code RC4100, Washington, DC 20460; and 40CFR§131.36(b)(1). Conversion

Factors applied in the table can be found in Appendix A to the Preamble- Conversion Factors for Dissolved Metals.

E The freshwater criterion for this metal is expressed as a function of hardness (mg/L) in the water column. The value given here corresponds to a hardness of

100 mg/L. Criteria values for other hardness may be calculated from the following: CMC (dissolved) = exp{mA [ln( hardness)]+ bA} (CF), or CCC (dissolved) =

exp{mC [ln (hardness)]+ bC} (CF) and the parameters specified in Appendix B to the Preamble- Parameters for Calculating Freshwater Dissolved Metals Criteria 

That Are Hardness-Dependent.

F Freshwater aquatic life values for pentachlorophenol are expressed as a function of pH, and are calculated as follows: CMC = exp(1.005(pH)-4.869); 

 CCC = exp(1.005(pH)-5.134). Values displayed in table correspond to a pH of 7.8.

G This Criterion is based on 304(a) aquatic life criterion issued in 1980, and was issued in one of the following documents: Aldrin/Dieldrin (EPA 440/5-80-019), 

Chlordane (EPA 440/5-80-027), DDT (EPA 440/5-80-038), Endosulfan (EPA 440/5-80-046), Endrin (EPA 440/5-80-047), Heptachlor (440/5-80-052), 

Hexachlorocyclohexane (EPA 440/5-80-054), Silver (EPA 440/5-80-071). The Minimum Data Requirements and derivation procedures were different in the 1980 

Guidelines than in the 1985 Guidelines. For example, a “CMC” derived using the 1980 Guidelines was derived to be used as an instantaneous maximum. If 

assessment is to be done using an averaging period, the values given should be divided by 2 to obtain a value that is more comparable to a CMC derived using the 

1985 Guidelines. 

H No criterion for protection of human health from consumption of aquatic organisms excluding water was presented in the 1980 criteria document or in the 1986 

Quality Criteria for Water. Nevertheless, sufficient information was presented in the 1980 document to allow the calculation of a criterion, even though the results

of such a calculation were not shown in the document.

I This criterion for asbestos is the Maximum Contaminant Level (MCL) developed under the Safe Drinking Water Act (SDWA).

J EPA has not calculated human health criterion for this contaminant. However, permit authorities should address this contaminant in NPDES permit actions using 

the State's existing narrative criteria for toxics.

K This recommended criterion is based on a 304(a) aquatic life criterion that was issued in the 1995 Updates: Water Quality Criteria Documents for the Protection

of Aquatic Life in Ambient Water, (EPA-820-B-96-001, September 1996). This value was derived using the GLI Guidelines (60FR15393-15399, March 23, 1995; 

40CFR132 Appendix A); the difference between the 1985 Guidelines and the GLI Guidelines are explained on page iv of the 1995 Updates. None of the decisions 

concerning the derivation of this criterion were affected by any considerations that are specific to the Great Lakes. 

L The CMC = 1/[(f1/CMC1) + (f2/CMC2)] where f1 and f2 are the fractions of total selenium that are treated as selenite and selenate, respectively, and CMC1 and

CMC2 are 185.9 Fg/l and 12.83 Fg/l, respectively.

M EPA is currently reassessing the criteria for arsenic. Upon completion of the reassessment the Agency will publish revised criteria as appropriate.

N PCBs are a class of chemicals which include aroclors, 1242, 1254, 1221, 1232, 1248, 1260, and 1016, CAS numbers 53469219, 11097691, 11104282, 11141165, 

12672296, 11096825 and 12674112 respectively. The aquatic life criteria apply to this set of PCBs.

O The derivation of the CCC for this pollutant did not consider exposure through the diet, which is probably important for aquatic life occupying upper trophic 

levels. 

P This criterion applies to total pcbs, i.e., the sum of all congener or all isomer analyses.

Q This recommended water quality criterion is expressed as Fg free cyanide (as CN)/L.

R This value was announced (61FR58444-58449, November 14, 1996) as a proposed GLI 303(c) aquatic life criterion. EPA is currently working on this criterion 

and so this value might change substantially in the near future.

S This recommended water quality criterion refers to the inorganic form only.

T This recommended water quality criterion is expressed in terms of total recoverable metal in the water column. It is scientifically acceptable to use the conversion 

factor of 0.922 that was used in the GLI to convert this to a value that is expressed in terms of dissolved metal.

U The organoleptic effect criterion is more stringent than the value for priority toxic pollutants.
15

V This value was derived from data for heptachlor and the criteria document provides insufficient data to estimate the relative toxicities of heptachlor and heptachlor 

epoxide.

W Although EPA has not published a final criteria document for this compound it is EPA’s understanding that sufficient data exist to allow calculation of aquatic 

criteria. It is anticipated that industry intends to publish in the peer reviewed literature draft aquatic life criteria generated in accordance with EPA Guidelines. 

EPA will review such criteria for possible issuance as national WQC.

X There is a full set of aquatic life toxicity data that show that DEHP is not toxic to aquatic organisms at or below its solubility limit. 

Y This value was derived from data for endosulfan and is most appropriately applied to the sum of alpha-endosulfan and beta-endosulfan.

Z A more stringent MCL has been issued by EPA. Refer to drinking water regulations (40 CFR 141) or Safe Drinking Water Hotline (1-800-426-4791) for values.

aa This CCC is based on the Final Residue Value procedure in the 1985 Guidelines. Since the publication of the Great Lakes Aquatic Life Criteria Guidelines in

1995 (60FR15393-15399, March 23, 1995), the Agency no longer uses the Final Residue Value procedure for deriving CCCs for new or revised 304(a) aquatic life

criteria.

bb This water quality criterion is based on a 304(a) aquatic life criterion that was derived using the 1985 Guidelines (Guidelines for Deriving Numerical National 

Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses, PB85-227049, January 1985) and was issued in one of the following criteria 

documents: Arsenic (EPA 440/5-84-033), Cadmium (EPA 440/5-84-032), Chromium (EPA 440/5-84-029), Copper (EPA 440/5-84-031), Cyanide (EPA 440/5- 

84-028), Lead (EPA 440/5-84-027), Nickel (EPA 440/5-86-004), Pentachlorophenol (EPA 440/5-86-009), Toxaphene, (EPA 440/5-86-006), Zinc (EPA 

440/5-87- 003). 

cc When the concentration of dissolved organic carbon is elevated, copper is substantially less toxic and use of Water-Effect Ratios might be appropriate.

dd The selenium criteria document (EPA 440/5-87-006, September 1987) provides that if selenium is as toxic to saltwater fishes in the field as it is to freshwater

fishes in the field, the status of the fish community should be monitored whenever the concentration of selenium exceeds 5.0 Fg/L in salt water because the

saltwater CCC does not take into account uptake via the food chain.

ee This recommended water quality criterion was derived on page 43 of the mercury criteria document (EPA 440/5-84-026, January 1985). The saltwater CCC of

0.025 ug/L given on page 23 of the criteria document is based on the Final Residue Value procedure in the 1985 Guidelines. Since the publication of the Great

Lakes Aquatic Life Criteria Guidelines in 1995 (60FR15393-15399, March 23, 1995), the Agency no longer uses the Final Residue Value procedure for deriving

CCCs for new or revised 304(a) aquatic life criteria.

ff This recommended water quality criterion was derived in Ambient Water Quality Criteria Saltwater Copper Addendum (Draft, April 14, 1995) and was

promulgated in the Interim final National Toxics Rule (60FR22228-222237, May 4, 1995).

gg EPA is actively working on this criterion and so this recommended water quality criterion may change substantially in the near future.

hh This recommended water quality criterion was derived from data for inorganic mercury (II), but is applied here to total mercury. If a substantial portion of the 

mercury in the water column is methylmercury, this criterion will probably be under protective. In addition, even though inorganic mercury is converted to 

methylmercury and methylmercury bioaccumulates to a great extent, this criterion does not account for uptake via the food chain because sufficient data were not 

available when the criterion was derived.
NATIONAL RECOMMENDED WATER QUALITY CRITERIA FOR NON PRIORITY POLLUTANTS

16

Non Priority Pollutant

CAS

Number

 Freshwater

 CMC CCC

(Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

(Fg/L) (Fg/L) 

Human Health

 For Consumption of:

 Water + Organism

Organism (Fg/L) Only (Fg/L)

FR

Cite/Source

1 Alkalinity -- 20000 F Gold Book

2 Aluminum pH 6.5 - 9.0 7429905 750 G,I 87 G,I,L 53FR33178

3 Ammonia 7664417 FRESHWATER CRITERIA ARE pH DEPENDENT -- SEE DOCUMENT D

SALTWATER CRITERIA ARE pH AND TEMPERATURE DEPENDENT

EPA822-R-98-008

EPA440/5-88-004

4 Aesthetic Qualities -- NARRATIVE STATEMENT-- SEE DOCUMENT Gold Book

5 Bacteria -- FOR PRIMARY RECREATION AND SHELLFISH USES -- SEE DOCUMENT Gold Book

6 Barium 7440393 1,000 A Gold Book

7 Boron -- NARRATIVE STATEMENT-- SEE DOCUMENT Gold Book

8 Chloride 16887006 860000 G 230000 G 53FR19028

9 Chlorine 7782505 19 11 13 7.5 C Gold Book

10 Chlorophenoxy Herbicide

2,4,5,-TP

93721 10 A Gold Book

11 Chlorophenoxy Herbicide

2,4-D

94757 100 A,C Gold Book

12 Chloropyrifos 2921882 0.083 G 0.041 G 0.011 G 0.0056 G Gold Book

13 Color -- NARRATIVE STATEMENT-- SEE DOCUMENT F Gold Book

14 Demeton 8065483 0.1 F 0.1 F Gold Book

15 Ether, Bis Chloromethyl 542881 0.00013 E 0.00078 E IRIS 01/01/91

16 Gases, Total Dissolved -- NARRATIVE STATEMENT -- SEE DOCUMENT F Gold Book

17 Guthion 86500 0.01 F 0.01 F Gold Book

18 Hardness -- NARRATIVE STATEMENT-- SEE DOCUMENT Gold Book
Non Priority Pollutant

CAS

Number

 Freshwater

 CMC CCC

(Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

(Fg/L) (Fg/L) 

Human Health

 For Consumption of:

 Water + Organism

Organism (Fg/L) Only (Fg/L)

FR

Cite/Source

17

19 Hexachlorocyclo-hexaneTechnical319868 0.0123 0.0414 Gold Book

20 Iron 7439896 1000 F 300 A Gold Book

21 Malathion 121755 0.1 F 0.1 F Gold Book

22 Manganese 7439965 50 A 100 A Gold Book

23 Methoxychlor 72435 0.03 F 0.03 F 100 A,C Gold Book

24 Mirex 2385855 0.001 F 0.001 F Gold Book

25 Nitrates 14797558 10,000 A Gold Book

26 Nitrosamines -- 0.0008 1.24

27 Dinitrophenols 25550587 70 14,000 Gold Book

28 Nitrosodibutylamine,N 924163 0.0064 A 0.587 A Gold Book

29 Nitrosodiethylamine,N 55185 0.0008 A 1.24 A Gold Book

30 Nitrosopyrrolidine,N 930552 0.016 91.9 Gold Book

31 Oil and Grease -- NARRATIVE STATEMENT -- SEE DOCUMENT F Gold Book

32 Oxygen, Dissolved 7782447 WARMWATER AND COLDWATER MATRIX -- SEE DOCUMENT O Gold Book

33 Parathion 56382 0.065 J 0.013 J Gold Book

34 Pentachlorobenzene 608935 3.5 E 4.1 E IRIS 03/01/88

35 pH -- 6.5 - 9 F 6.5 - 8.5 F,K 5 - 9 Gold Book

36 Phosphorus Elemental 7723140 0.1 F,K Gold Book

37 Phosphate Phosphorus -- NARRATIVE STATEMENT-- SEE DOCUMENT Gold Book
Non Priority Pollutant

CAS

Number

 Freshwater

 CMC CCC

(Fg/L) (Fg/L) 

 Saltwater

 CMC CCC

(Fg/L) (Fg/L) 

Human Health

 For Consumption of:

 Water + Organism

Organism (Fg/L) Only (Fg/L)

FR

Cite/Source

18

38 Solids Dissolved and

Salinity

-- 250,000 A Gold Book

39 Solids Suspended and

Turbidity

-- NARRATIVE STATEMENT -- SEE DOCUMENT F Gold Book

40 Sulfide-Hydrogen Sulfide 7783064 2.0 F 2.0 F Gold Book

41 Tainting Substances -- NARRATIVE STATEMENT-- SEE DOCUMENT Gold Book

42 Temperature -- SPECIES DEPENDENT CRITERIA -- SEE DOCUMENT M Gold Book

43 Tetrachlorobenzene,1,2,4,

5-

95943 2.3 E 2.9 E IRIS03/01/91

44 Tributyltin TBT -- 0.46 N 0.063 N 0.37 N 0.010 N 62FR42554

45 Trichlorophenol,2,4,5- 95954 2,600 B,E 9800 B,E IRIS 03/01/88

Footnotes:

A This human health criterion is the same as originally published in the Red Book which predates the 1980 methodology and did not utilize the fish ingestion BCF 

approach. This same criterion value is now published in the Gold Book.

B The organoleptic effect criterion is more stringent than the value presented in the non priority pollutants table.

C A more stringent Maximum Contaminant Level (MCL) has been issued by EPA under the Safe Drinking Water Act. Refer to drinking water regulations

40CFR141 or Safe Drinking Water Hotline (1-800-426-4791) for values.

D According to the procedures described in the Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and

Their Uses, except possibly where a very sensitive species is important at a site, freshwater aquatic life should be protected if both conditions specified in

Appendix C to the Preamble- Calculation of Freshwater Ammonia Criterion are satisfied.

E This criterion has been revised to reflect The Environmental Protection Agency’s q1* or RfD, as contained in the Integrated Risk Information System (IRIS) as of 

April 8, 1998. The fish tissue bioconcentration factor (BCF) used to derive the original criterion was retained in each case.

F The derivation of this value is presented in the Red Book (EPA 440/9-76-023, July, 1976).

G This value is based on a 304(a) aquatic life criterion that was derived using the 1985 Guidelines (Guidelines for Deriving Numerical National Water Quality

Criteria for the Protection of Aquatic Organisms and Their Uses, PB85-227049, January 1985) and was issued in one of the following criteria documents:

Aluminum (EPA 440/5-86-008); Chloride (EPA 440/5-88-001); Chloropyrifos (EPA 440/5-86-005).

I This value is expressed in terms of total recoverable metal in the water column.

J This value is based on a 304(a) aquatic life criterion that was issued in the 1995 Updates: Water Quality Criteria Documents for the Protection of Aquatic Life in 

Ambient Water (EPA-820-B-96-001). This value was derived using the GLI Guidelines (60FR15393-15399, March 23, 1995; 40CFR132 Appendix A); the 

differences between the 1985 Guidelines and the GLI Guidelines are explained on page iv of the 1995 Updates. No decision concerning this criterion was affected

by any considerations that are specific to the Great Lakes.
19

K According to page 181 of the Red Book:

For open ocean waters where the depth is substantially greater than the euphotic zone, the pH should not be changed more than 0.2 units from the naturally

occurring variation or any case outside the range of 6.5 to 8.5. For shallow, highly productive coastal and estuarine areas where naturally occurring pH

variations approach the lethal limits of some species, changes in pH should be avoided but in any case should not exceed the limits established for fresh

water, i.e., 6.5-9.0.

L There are three major reasons why the use of Water-Effect Ratios might be appropriate. (1) The value of 87 Fg/l is based on a toxicity test with the striped bass in 

water with pH= 6.5-6.6 and hardness <10 mg/L. Data in “Aluminum Water-Effect Ratio for the 3M Plant Effluent Discharge, Middleway, West Virginia” (May 

1994) indicate that aluminum is substantially less toxic at higher pH and hardness, but the effects of pH and hardness are not well quantified at this time. (2) In

tests with the brook trout at low pH and hardness, effects increased with increasing concentrations of total aluminum even though the concentration of dissolved

aluminum was constant, indicating that total recoverable is a more appropriate measurement than dissolved, at least when particulate aluminum is primarily

aluminum hydroxide particles. In surface waters, however, the total recoverable procedure might measure aluminum associated with clay particles, which might

be less toxic than aluminum associated with aluminum hydroxide. (3) EPA is aware of field data indicating that many high quality waters in the U.S. contain

more than 87 Fg aluminum/L, when either total recoverable or dissolved is measured.

M U.S. EPA. 1973. Water Quality Criteria 1972. EPA-R3-73-033. National Technical Information Service, Springfield, VA.; U.S. EPA. 1977. Temperature

Criteria for Freshwater Fish: Protocol and Procedures. EPA-600/3-77-061. National Technical Information Service, Springfield, VA. 

N This value was announced (62FR42554, August 7, 1997) as a proposed 304(a) aquatic life criterion. Although EPA has not responded to public comment, EPA is 

publishing this as a 304(a) criterion in today’s notice as guidance for States and Tribes to consider when adopting water quality criteria.

O U.S. EPA. 1986. Ambient Water Quality Criteria for Dissolved Oxygen. EPA 440/5-86-003. National Technical Information Service, Springfield, VA.
NATIONAL RECOMMENDED WATER QUALITY CRITERIA FOR ORGANOLEPTIC EFFECTS

20

 Pollutant CAS Number

Organoleptic Effect Criteria 

(Fg/L) FR Cite/Source

1 Acenaphthene 83329 20 Gold Book

2 Monochlorobenzene 108907 20 Gold Book

3 3-Chlorophenol -- 0.1 Gold Book

4 4-Chlorophenol 106489 0.1 Gold Book

5 2,3-Dichlorophenol -- 0.04 Gold Book

6 2,5-Dichlorophenol -- 0.5 Gold Book

7 2,6-Dichlorophenol -- 0.2 Gold Book

8 3,4-Dichlorophenol -- 0.3 Gold Book

9 2,4,5-Trichlorophenol 95954 1 Gold Book

10 2,4,6-Trichloropehnol 88062 2 Gold Book

11 2,3,4,6-Tetrachlorophenol -- 1 Gold Book

12 2-Methyl-4-Chlorophenol -- 1800 Gold Book

13 3-Methyl-4-Chlorophenol 59507 3000 Gold Book

14 3-Methyl-6-Chlorophenol -- 20 Gold Book

15 2-Chlorophenol 95578 0.1 Gold Book

16 Copper 7440508 1000 Gold Book

17 2,4-Dichlorophenol 120832 0.3 Gold Book

18 2,4-Dimethylpehnol 105679 400 Gold Book

19 Hexachlorocyclopentadiene 77474 1 Gold Book

20 Nitrobenzene 98953 30 Gold Book
 Pollutant CAS Number

Organoleptic Effect Criteria 

(Fg/L) FR Cite/Source

21

21 Pentachlorophenol 87865 30 Gold Book

22 Phenol 108952 300 Gold Book

23 Zinc 7440666 5000 45 FR79341

General Notes:

1. These criteria are based on organoleptic (taste and odor) effects. Because of variations in chemical nomenclature systems, this listing of pollutants does not

duplicate the listing in Appendix A of 40 CFR Part 423. Also listed are the Chemical Abstracts Service (CAS) registry numbers, which provide a unique

identification for each chemical.

NATIONAL RECOMMENDED WATER QUALITY CRITERIA

Additional Notes:

1. Criteria Maximum Concentration and Criterion Continuous Concentration

 The Criteria Maximum Concentration (CMC) is an estimate of the highest concentration of a material in surface water to which an aquatic community can be

exposed briefly without resulting in an unacceptable effect. The Criterion Continuous Concentration (CCC) is an estimate of the highest concentration of a material in

surface water to which an aquatic community can be exposed indefinitely without resulting in an unacceptable effect. The CMC and CCC are just two of the six parts

of a aquatic life criterion; the other four parts are the acute averaging period, chronic averaging period, acute frequency of allowed exceedence, and chronic frequency

of allowed exceedence. Because 304(a) aquatic life criteria are national guidance, they are intended to be protective of the vast majority of the aquatic communities in

the United States.

2. Criteria Recommendations for Priority Pollutants, Non Priority Pollutants and Organoleptic Effects

This compilation lists all priority toxic pollutants and some non priority toxic pollutants, and both human health effect and organoleptic effect criteria issued

pursuant to CWA §304(a). Blank spaces indicate that EPA has no CWA §304(a) criteria recommendations. For a number of non-priority toxic pollutants not listed,

CWA §304(a) “water + organism” human health criteria are not available, but, EPA has published MCLs under the SDWA that may be used in establishing water

quality standards to protect water supply designated uses. Because of variations in chemical nomenclature systems, this listing of toxic pollutants does not duplicate

the listing in Appendix A of 40 CFR Part 423. Also listed are the Chemical Abstracts Service CAS registry numbers, which provide a unique identification for each

chemical.

3. Human Health Risk

The human health criteria for the priority and non priority pollutants are based on carcinogenicity of 10-6 risk. Alternate risk levels may be obtained by moving the

decimal point (e.g., for a risk level of 10-5, move the decimal point in the recommended criterion one place to the right).
22

4. Water Quality Criteria published pursuant to Section 304(a) or Section 303(c) of the CWA

Many of the values in the compilation were published in the proposed California Toxics Rule (CTR, 62FR42160). Although such values were published pursuant

to Section 303(c) of the CWA, they represent the Agency’s most recent calculation of water quality criteria and thus are published today as the Agency’s 304(a)

criteria. Water quality criteria published in the proposed CTR may be revised when EPA takes final action on the CTR.

5. Calculation of Dissolved Metals Criteria

The 304(a) criteria for metals, shown as dissolved metals, are calculated in one of two ways. For freshwater metals criteria that are hardness-dependent, the

dissolved metal criteria were calculated using a hardness of 100 mg/l as CaCO3 for illustrative purposes only. Saltwater and freshwater metals’ criteria that are not

hardness-dependent are calculated by multiplying the total recoverable criteria before rounding by the appropriate conversion factors. The final dissolved metals’

criteria in the table are rounded to two significant figures. Information regarding the calculation of hardness dependent conversion factors are included in the

footnotes.

6. Correction of Chemical Abstract Services Number

The Chemical Abstract Services number (CAS) for Bis(2-Chloroisoprpyl) Ether, has been corrected in the table. The correct CAS number for this chemical is

39638-32-9. Previous publications listed 108-60-1 as the CAS number for this chemical.

7. Maximum Contaminant Levels

The compilation includes footnotes for pollutants with Maximum Contaminant Levels (MCLs) more stringent than the recommended water quality criteria in the

compilation. MCLs for these pollutants are not included in the compilation, but can be found in the appropriate drinking water regulations (40 CFR 141.11-16 and

141.60-63), or can be accessed through the Safe Drinking Water Hotline (800-426-4791) or the Internet (http://www.epa.gov/ost/tools/dwstds-s.html).

8. Organoleptic Effects

The compilation contains 304(a) criteria for pollutants with toxicity-based criteria as well as non-toxicity based criteria. The basis for the non-toxicity based

criteria are organoleptic effects (e.g., taste and odor) which would make water and edible aquatic life unpalatable but not toxic to humans. The table includes criteria

for organoleptic effects for 23 pollutants. Pollutants with organoleptic effect criteria more stringent than the criteria based on toxicity (e.g., included in both the

priority and non-priority pollutant tables) are footnoted as such.

9. Category Criteria

In the 1980 criteria documents, certain recommended water quality criteria were published for categories of pollutants rather than for individual pollutants within

that category. Subsequently, in a series of separate actions, the Agency derived criteria for specific pollutants within a category. Therefore, in this compilation EPA is

replacing criteria representing categories with individual pollutant criteria (e.g., 1,3-dichlorobenzene, 1,4-dichlorobenzene and 1,2-dichlorobenzene).

10. Specific Chemical Calculations

A. Selenium

 (1) Human Health

 In the 1980 Selenium document, a criterion for the protection of human health from consumption of water and organisms was calculated based on a BCF of

6.0 L/kg and a maximum water-related contribution of 35 Fg Se/day. Subsequently, the EPA Office of Health and Environmental Assessment issued an errata notice

(February 23, 1982), revising the BCF for selenium to 4.8 L/kg. In 1988, EPA issued an addendum (ECAO-CIN-668) revising the human health criteria for selenium. 

Later in the final National Toxic Rule (NTR, 57 FR 60848), EPA withdrew previously published selenium human health criteria, pending Agency review of new

epidemiological data.
23

This compilation includes human health criteria for selenium, calculated using a BCF of 4.8 L/kg along with the current IRIS RfD of 0.005 mg/kg/day. EPA 

included these recommended water quality criteria in the compilation because the data necessary for calculating a criteria in accordance with EPA’s 1980 human

health methodology are available.

(2) Aquatic Life

This compilation contains aquatic life criteria for selenium that are the same as those published in the proposed CTR. In the CTR, EPA proposed an acute

criterion for selenium based on the criterion proposed for selenium in the Water Quality Guidance for the Great Lakes System (61 FR 58444). The GLI and CTR

proposals take into account data showing that selenium’s two most prevalent oxidation states, selenite and selenate, present differing potentials for aquatic toxicity, as

well as new data indicating that various forms of selenium are additive. The new approach produces a different selenium acute criterion concentration, or CMC,

depending upon the relative proportions of selenite, selenate, and other forms of selenium that are present. 

EPA notes it is currently undertaking a reassessment of selenium, and expects the 304(a) criteria for selenium will be revised based on the final reassessment

(63FR26186). However, until such time as revised water quality criteria for selenium are published by the Agency, the recommended water quality criteria in this

compilation are EPA’s current 304(a) criteria.

B. 1,2,4-Trichlorobenzene and Zinc

Human health criteria for 1,2,4-trichlorobenzene and zinc have not been previously published. Sufficient information is now available for calculating water quality

criteria for the protection of human health from the consumption of aquatic organisms and the consumption of aquatic organisms and water for both these compounds. 

Therefore, EPA is publishing criteria for these pollutants in this compilation.

C. Chromium (III)

The recommended aquatic life water quality criteria for chromium (III) included in the compilation are based on the values presented in the document titled: 1995

Updates: Water Quality Criteria Documents for the Protection of Aquatic Life in Ambient Water, however, this document contains criteria based on the total

recoverable fraction. The chromium (III) criteria in this compilation were calculated by applying the conversion factors used in the Final Water Quality Guidance for

the Great Lakes System (60 FR 15366) to the 1995 Update document values.

 

D. Ether, Bis (Chloromethyl), Pentachlorobenzene, Tetrachlorobenzene 1,2,4,5-, Trichlorphenol 

Human health criteria for these pollutants were last published in EPA’s Quality Criteria for Water 1986 or “Gold Book”. Some of these criteria were calculated

using Acceptable Daily Intake (ADIs) rather than RfDs. Updated q1*s and RfDs are now available in IRIS for ether, bis (chloromethyl), pentachlorobenzene,

tetrachlorobenzene 1,2,4,5-, and trichlorophenol, and were used to revise the water quality criteria for these compounds. The recommended water quality criteria for

ether, bis (chloromethyl) were revised using an updated q1*, while criteria for pentachlorobenzene, and tetrachlorobenzene 1,2,4,5-, and trichlorophenol were derived

using an updated RfD value.

E. PCBs

In this compilation EPA is publishing aquatic life and human health criteria based on total PCBs rather than individual arochlors. These criteria replace the

previous criteria for the seven individual arochlors. Thus, there are criteria for a total of 102 of the 126 priority pollutants.
24

Appendix A - Conversion Factors for Dissolved Metals

Metal Conversion Factor

freshwater CMC

Conversion Factor

freshwater CCC

Conversion Factor

saltwater CMC

Conversion Factor

saltwater CCC1

Arsenic 1.000 1.000 1.000 1.000

Cadmium 1.136672-[(ln

hardness)(0.041838)]

1.101672-[(ln

hardness)(0.041838)] 0.994 0.994

Chromium III 0.316 0.860 -- --

Chromium VI 0.982 0.962 0.993 0.993

Copper 0.960 0.960 0.83 0.83

Lead 1.46203-[(ln

hardness)(0.145712)]

 1.46203-[(ln

hardness)(0.145712)] 0.951 0.951

Mercury 0.85 0.85 0.85 0.85

Nickel 0.998 0.997 0.990 0.990

Selenium -- -- 0.998 0.998

Silver 0.85 -- 0.85 --

Zinc 0.978 0.986 0.946 0.946
25

Appendix B - Parameters for Calculating Freshwater Dissolved Metals Criteria That Are Hardness-Dependent

Chemical mA bA mC bC

Freshwater Conversion Factors (CF)

Acute Chronic

Cadmium 1.128 -3.6867 0.7852 -2.715 1.136672-[ln

(hardness)(0.041838)]

1.101672-[ln

(hardness)(0.041838)]

Chromium III 0.8190 3.7256 0.8190 0.6848 0.316 0.860

Copper 0.9422 -1.700 0.8545 -1.702 0.960 0.960

Lead 1.273 -1.460 1.273 -4.705 1.46203-[ln

(hardness)(0.145712)]

1.46203-[ln

(hardness)(0.145712)]

Nickel 0.8460 2.255 0.8460 0.0584 0.998 0.997

Silver 1.72 -6.52 -- -- 0.85 --

Zinc 0.8473 0.884 0.8473 0.884 0.978 0.986

Appendix C - Calculation of Freshwater Ammonia Criterion

1. The one-hour average concentration of total ammonia nitrogen (in mg N/L) does not exceed, more than once every three years on the average, the 

CMC calculated using the following equation:

 0.275 39.0

CMC = -------------------- + ------------------------

 1 + 107.204-pH 1 + 10pH-7.204 

 In situations where salmonids do not occur, the CMC may be calculated using the following equation:

 0.411 58.4

CMC = -------------------- + ------------------------

 1 + 107.204-pH 1 + 10pH-7.204 

2. The thirty-day average concentration of total ammonia nitrogen (in mg N/L) does not exceed, more than once every three years on the average, the 

CCC calculated using the following equation:

 0.0858 3.70

CCC = -------------------- + ------------------------

 1 + 107.688-pH 1 + 10pH-7.688

and the highest four-day average within the 30-day period does not exceed twice the CCC.