## 481 Environmental Protection Agency § 131.36

North Star Creek ....................... Class IIIOkanogan River from Reservation north boundary to Columbia River. Class II

Olds Creek ................................ Class I Omak Creek .............................. Class II Onion Creek .............................. Class II Parmenter Creek ....................... Class III Peel Creek ................................. Class III Peter Dan Creek ....................... Class III Rock Creek ................................ Class I San Poil River ........................... Class I Sanpoil, River West Fork .......... Class II Seventeen Mile Creek ............... Class III Silver Creek ............................... Class III Sitdown Creek ........................... Class III Six Mile Creek ........................... Class III South Nanamkin Creek ............. Class III Spring Creek ............................. Class III Stapaloop Creek ........................ Class III Stepstone Creek ........................ Class III Stranger Creek .......................... Class II Strawberry Creek ....................... Class III Swimptkin Creek ....................... Class III Three Forks Creek .................... Class I Three Mile Creek ....................... Class III Thirteen Mile Creek ................... Class II Thirty Mile Creek ....................... Class II Trail Creek ................................. Class III Twentyfive Mile Creek ............... Class III Twentyone Mile Creek .............. Class III Twentythree Mile Creek ............ Class III Wannacot Creek ........................ Class III Wells Creek ............................... Class I Whitelaw Creek ......................... Class III Wilmont Creek ........................... Class II (2) Lakes: Apex Lake ................................. LC Big Goose Lake ......................... LC Bourgeau Lake .......................... LC
Buffalo Lake .............................. LC Cody Lake ................................. LC
Crawfish Lakes .......................... LC
Camille Lake .............................. LC
Elbow Lake ................................ LC
Fish Lake ................................... LC
Gold Lake .................................. LC
Great Western Lake .................. LC
Johnson Lake ............................ LC
LaFleur Lake ............................. LC
Little Goose Lake ...................... LC
Little Owhi Lake ......................... LC
McGinnis Lake ........................... LC
Nicholas Lake ............................ LC
Omak Lake ................................ SRW
Owhi Lake ................................. SRW Penley Lake ............................... SRW
Rebecca Lake ........................... LC
Round Lake ............................... LC Simpson Lake ............................ LC Soap Lake ................................. LC Sugar Lake ................................ LC
Summit Lake ............................. LC
Twin Lakes ................................ SRW

[54 FR 28625, July 6, 1989]



### § 131.36 Toxics criteria for those states not complying with Clean Water Act section 303(c)(2)(B).

(a) Scope. This section is not a general promulgation of the section 304(a) criteria for priority toxic pollutants but is restricted to specific pollutants in specific States.

(b)(1) EPA’s Section 304(a) criteria for Priority Toxic Pollutants.


## 482 40 CFR Ch. I (7–1–10 Edition) § 131.36A BFreshwaterCSaltwaterDHuman Health(10¥6risk for carcinogens)For consumption of:(#) Compound CAS NumberCriterionMaximumConc.d(μg/L)(B1)CriterionContinuousConc.d(μg/L)(B2)CriterionMaximumConc.d(μg/L)(C1)CriterionContinuousConc.d(μg/L)(C2)Water &Organisms(μg/L)(D1)OrganismsOnly(μg/L)(D2)1 Antimony ................................................................... 7440360 .......................... .......................... .......................... .......................... 14 a 4300 a2 Arsenic ...................................................................... 7440382 360 m 190 m 69 m 36 m 0.018 abc 0.14 abc3 Beryllium ................................................................... 7440417 .......................... .......................... .......................... .......................... n n4 Cadmium ................................................................... 7440439 3.7 e 1.0 e 42 m 9.3 m n n5a Chromium (III) ........................................................... 16065831 550 e 180 e .......................... .......................... n nb Chromium (VI) ........................................................... 18540299 15 m 10 m 1100 m 50 m n n6 Copper ...................................................................... 7440508 17 e 11 e 2.4 m 2.4 m7 Lead .......................................................................... 7439921 65 e 2.5 e 210 m 8.1 m n n8 Mercury ..................................................................... 7439976 2.1 m 0.012 ip 1.8 m 0.025 ip 0.14 0.159 Nickel ........................................................................ 7440020 1400 e 160 e 74 m 8.2 m 610 a 4600 a10 Selenium ................................................................... 7782492 20 p 5 p 290 m 71 m n n11 Silver ......................................................................... 7440224 3.4 e .......................... 1.9 m12 Thallium .................................................................... 7440280 .......................... .......................... .......................... .......................... 1.7 a 6.3 a13 Zinc ........................................................................... 7440666 110 e 100 e 90 m 81 m14 Cyanide ..................................................................... 57125 22 5.2 1 1 700 a 220000 aj15 Asbestos ................................................................... 1332214 .......................... .......................... .......................... .......................... 7,000,000fibers/L k16 2,3,7,8-TCDD (Dioxin) .............................................. 1746016 .......................... .......................... .......................... .......................... 0.000000013 c 0.000000014 c17 Acrolein ..................................................................... 107028 .......................... .......................... .......................... .......................... 320 78018 Acrylonitrile ............................................................... 107131 .......................... .......................... .......................... .......................... 0.059 ac 0.66 ac19 Benzene .................................................................... 71432 .......................... .......................... .......................... .......................... 1.2 ac 71 ac20 Bromoform ................................................................ 75252 .......................... .......................... .......................... .......................... 4.3 ac 360 ac21 Carbon Tetrachloride ................................................ 56235 .......................... .......................... .......................... .......................... 0.25 ac 4.4 ac22 Chlorobenzene ......................................................... 108907 .......................... .......................... .......................... .......................... 680 a 21000 aj23 Chlorodibromomethane ............................................ 124481 .......................... .......................... .......................... .......................... 0.41 ac 34 ac24 Chloroethane ............................................................ 7500325 2-Chloroethylvinyl Ether ........................................... 11075826 Chloroform ................................................................ 67663 .......................... .......................... .......................... .......................... 5.7 ac 470 ac27 Dichlorobromomethane ............................................ 75274 .......................... .......................... .......................... .......................... 0.27 ac 22 ac28 1,1-Dichloroethane ................................................... 7534329 1,2-Dichloroethane ................................................... 107062 .......................... .......................... .......................... .......................... 0.38 ac 99 ac30 1,1-Dichloroethylene ................................................. 75354 .......................... .......................... .......................... .......................... 0.057 ac 3.2 ac31 1,2-Dichloropropane ................................................. 7887532 1,3-Dichloropropylene ............................................... 542756 .......................... .......................... .......................... .......................... 10 a 1700 a33 Ethylbenzene ............................................................ 100414 .......................... .......................... .......................... .......................... 3100 a 29000 a34 Methyl Bromide ......................................................... 74839 .......................... .......................... .......................... .......................... 48 a 4000 a35 Methyl Chloride ......................................................... 74873 .......................... .......................... .......................... .......................... n n36 Methylene Chloride ................................................... 75092 .......................... .......................... .......................... .......................... 4.7 ac 1600 ac37 1,1,2,2-Tetrachloroethane ........................................ 79345 .......................... .......................... .......................... .......................... 0.17 ac 11 ac38 Tetrachloroethylene .................................................. 127184 .......................... .......................... .......................... .......................... 0.8 c 8.85 c39 Toluene ..................................................................... 108883 .......................... .......................... .......................... .......................... 6800 a 200000 a


## 483 Environmental Protection Agency § 131.3640 1,2-Trans-Dichloroethylene ...................................... 15660541 1,1,1-Trichloroethane ................................................ 71556 .......................... .......................... .......................... .......................... n n42 1,1,2-Trichloroethane ................................................ 79005 .......................... .......................... .......................... .......................... 0.60 ac 42 ac43 Trichloroethylene ...................................................... 79016 .......................... .......................... .......................... .......................... 2.7 c 81 c44 Vinyl Chloride ........................................................... 75014 .......................... .......................... .......................... .......................... 2 c 525 c45 2-Chlorophenol ......................................................... 9557846 2,4-Dichlorophenol .................................................... 120832 .......................... .......................... .......................... .......................... 93 a 790 aj47 2,4-Dimethylphenol ................................................... 10567948 2-Methyl-4,6-Dinitrophenol ....................................... 534521 .......................... .......................... .......................... .......................... 13.4 76549 2,4-Dinitrophenol ...................................................... 51285 .......................... .......................... .......................... .......................... 70 a 14000 a50 2-Nitrophenol ............................................................ 8875551 4-Nitrophenol ............................................................ 10002752 3-Methyl-4-Chlorophenol .......................................... 5950753 Pentachlorophenol .................................................... 87865 20 f 13 f 13 7.9 0.28 ac 8.2 acj54 Phenol ....................................................................... 108952 .......................... .......................... .......................... .......................... 21000 a 4600000 aj55 2,4,6-Trichlorophenol ................................................ 88062 .......................... .......................... .......................... .......................... 2.1 ac 6.5 ac56 Acenaphthene ........................................................... 8332957 Acenaphthylene ........................................................ 20896858 Anthracene ............................................................... 120127 .......................... .......................... .......................... .......................... 9600 a 110000 a59 Benzidine .................................................................. 92875 .......................... .......................... .......................... .......................... 0.00012 ac 0.00054 ac60 Benzo(a)Anthracene ................................................. 56553 .......................... .................................................... .......................... 0.0028 c 0.031 c61 Benzo(a)Pyrene ........................................................ 50328 .......................... .......................... .......................... .......................... 0.0028 c 0.031 c62 Benzo(b)Fluoranthene .............................................. 205992 .......................... .................................................... .......................... 0.0028 c 0.031 c63 Benzo(ghi)Perylene .................................................. 19124264 Benzo(k)Fluoranthene .............................................. 207089 .......................... .................................................... .......................... 0.0028 c 0.031 c65 Bis(2-Chloroethoxy)Methane .................................... 11191166 Bis(2-Chloroethyl)Ether ............................................ 111444 .......................... .......................... .......................... .......................... 0.031 ac 1.4 ac67 Bis(2-Chloroisopropyl)Ether ...................................... 108601 .......................... .......................... .......................... .......................... 1400 a 170000 a68 Bis(2-Ethylhexyl)Phthalate ........................................ 117817 .......................... .................................................... .......................... 1.8 ac 5.9 ac69 4-Bromophenyl Phenyl Ether ................................... 10155370 Butylbenzyl Phthalate ............................................... 8568771 2-Chloronaphthalene ................................................ 9158772 4-Chlorophenyl Phenyl Ether ................................... 700572373 Chrysene .................................................................. 218019 .......................... .......................... .......................... .......................... 0.0028 c 0.031 c74 Dibenzo(ah)Anthracene ............................................ 53703 .......................... .......................... .......................... .......................... 0.0028 c 0.031 c75 1,2-Dichlorobenzene ................................................. 95501 .......................... .......................... .......................... .......................... 2700 a 17000 a76 1,3-Dichlorobenzene ................................................. 541731 .......................... .......................... .......................... .......................... 400 260077 1,4-Dichlorobenzene ................................................. 106467 .......................... .......................... .......................... .......................... 400 260078 3,3′-Dichlorobenzidine .............................................. 91941 .......................... .......................... .......................... .......................... 0.04 ac 0.077 ac79 Diethyl Phthalate ...................................................... 84662 .......................... .......................... .......................... .......................... 23000 a 120000 a80 Dimethyl Phthalate ................................................... 131113 .......................... .......................... .......................... .......................... 313000 290000081 Di-n-Butyl Phthalate .................................................. 84742 .......................... .......................... .......................... .......................... 2700 a 12000 a82 2,4-Dinitrotoluene ..................................................... 121142 .......................... .......................... .......................... .......................... 0.11 c 9.1 c83 2,6-Dinitrotoluene ..................................................... 60620284 Di-n-Octyl Phthalate ................................................. 11784085 1,2-Diphenylhydrazine .............................................. 122667 .......................... .......................... .......................... .......................... 0.040 ac 0.54 ac86 Fluoranthene ............................................................. 206440 .......................... .......................... .......................... .......................... 300 a 370 a87 Fluorene .................................................................... 86737 .......................... .......................... .......................... .......................... 1300 a 14000 a88 Hexachlorobenzene .................................................. 118741 .......................... .......................... .......................... .......................... 0.00075 ac 0.00077 ac89 Hexachlorobutadiene ................................................ 87683 .......................... .................................................... .......................... 0.44 ac 50 ac


## 484 40 CFR Ch. I (7–1–10 Edition) § 131.36A BFreshwaterCSaltwaterDHuman Health(10¥6risk for carcinogens)For consumption of:(#) Compound CAS NumberCriterionMaximumConc.d(μg/L)(B1)CriterionContinuousConc.d(μg/L)(B2)CriterionMaximumConc.d(μg/L)(C1)CriterionContinuousConc.d(μg/L)(C2)Water &Organisms(μg/L)(D1)OrganismsOnly(μg/L)(D2)90 Hexachlorocyclopentadiene ...................................... 77474 .......................... .......................... .......................... .......................... 240 a 17000 aj91 Hexachloroethane ..................................................... 67721 .......................... .......................... .......................... .......................... 1.9 ac 8.9 ac92 Indeno(1,2,3-cd)Pyrene ............................................ 193395 .......................... .................................................... .......................... 0.0028 c 0.031 c93 Isophorone ................................................................ 78591 .......................... .......................... .......................... .......................... 8.4 ac 600 ac94 Naphthalene ............................................................. 9120395 Nitrobenzene ............................................................ 98953 .......................... .......................... .......................... .......................... 17 a 1900 aj96 N-Nitrosodimethylamine ........................................... 62759 .......................... .......................... .......................... .......................... 0.00069 ac 8.1 ac97 N-Nitrosodi-n-Propylamine ....................................... 62164798 N-Nitrosodiphenylamine ........................................... 86306 .......................... .......................... .......................... .......................... 5.0 ac 16 ac99 Phenanthrene ........................................................... 85018100 Pyrene ...................................................................... 129000 .......................... .......................... .......................... .......................... 960 a 11000 a101 1,2,4-Trichlorobenzene ............................................. 120821102 Aldrin ......................................................................... 309002 3 g .......................... 1.3 g .......................... 0.00013 ac 0.00014 ac103 alpha-BHC ................................................................ 319846 .......................... .......................... .......................... .......................... 0.0039 ac 0.013 ac104 beta-BHC .................................................................. 319857 .......................... .......................... .......................... .......................... 0.014 ac 0.046 ac105 gamma-BHC ............................................................. 58899 2 g 0.08 g 0.16 g .......................... 0.019 c 0.063 c106 delta-BHC ................................................................. 319868107 Chlordane ................................................................. 57749 2.4 g 0.0043 g 0.09 g 0.004 g 0.00057 ac 0.00059 ac108 4,4′-DDT ................................................................... 50293 1.1 g 0.001 g 0.13 g 0.001 g 0.00059 ac 0.00059 ac109 4,4′-DDE ................................................................... 72559 .......................... .......................... .......................... .......................... 0.00059 ac 0.00059 ac110 4,4′-DDD ................................................................... 72548 .......................... .......................... .......................... .......................... 0.00083 ac 0.00084 ac111 Dieldrin ...................................................................... 60571 2.5 g 0.0019 g 0.71 g 0.0019 g 0.00014 ac 0.00014 ac112 alpha-Endosulfan ...................................................... 959988 0.22 g 0.056 g 0.034 g 0.0087 g 0.93 a 2.0 a113 beta-Endosulfan ........................................................ 33213659 0.22 g 0.056 g 0.034 g 0.0087 g 0.93 a 2.0 a114 Endosulfan Sulfate ................................................... 1031078 .......................... .......................... .......................... .......................... 0.93 a 2.0 a115 Endrin ....................................................................... 72208 0.18 g 0.0023 g 0.037 g 0.0023 g 0.76 a 0.81 aj116 Endrin Aldehyde ....................................................... 7421934 .......................... .......................... .......................... .......................... 0.76 a 0.81 aj117 Heptachlor ................................................................ 76448 0.52 g 0.0038 g 0.053 g 0.0036 g 0.00021 ac0.00021 ac118 Heptachlor Epoxide .................................................. 1024573 0.52 g 0.0038 g 0.053 g 0.0036 g 0.00010 ac 0.00011 ac119 PCB–1242 ................................................................ 53469219 .......................... 0.014 g .......................... 0.03 g120 PCB–1254 ................................................................ 11097691 .......................... 0.014 g .......................... 0.03 g121 PCB–1221 ................................................................ 11104282 .......................... 0.014 g .......................... 0.03 g122 PCB–1232 ................................................................ 11141165 .......................... 0.014 g .......................... 0.03 g123 PCB–1248 ................................................................ 12672296 .......................... 0.014 g .......................... 0.03 g124 PCB–1260 ................................................................ 11096825 .......................... 0.014 g .......................... 0.03 g125a PCB–1016 ................................................................ 12674112 .......................... 0.014 g .......................... 0.03 g125b Polychlorinated biphenyls(PCBs) ................................................................... .......................... .......................... .......................... .......................... .......................... 0.00017 q 0.00017 q126 Toxaphene ................................................................ 8001352 0.73 0.0002 0.21 0.0002 0.00073 ac 0.00075acTotal Number of Criteria (h) = ............................... .......................... 24 29 23 27 85 84


## 485 Environmental Protection Agency § 131.36

F OOTNOTES
a. Criteria revised to reflect current agency q 1 * or RfD, as contained in the Integrated Risk Information System (IRIS). The fish tissue bioconcentration factor (BCF) from the 1980 criteria documents was retained in all cases.

b. The criteria refers to the inorganic form only.

c. Criteria in the matrix based on carcinogenicity (10

¥ 6 risk). For a risk level of 10

¥ 5

, move the decimal point in the matrix value one place to the right.

d. Criteria Maximum Concentration (CMC) = the highest concentration of a pollutant to which aquatic life can be exposed for a shortperiod of time (1-hour average) without deleterious effects. Criteria Continuous Concentration (CCC) = the highest concentration of a pollutant to which aquatic life can be exposed for an extended period of time (4 days) without deleterious effects. μ g/L = micrograms per liter.

e. Freshwater aquatic life criteria for these metals are expressed as a function of total hardness (mg/L as CaCO 3 ), the pollutant’s water effect ratio (WER) as defined in §131.36(c) and multiplied by an appropriate dissolved conversion factor as defined in §131.36(b)(2). For comparative purposes, the values displayed in this matrix are shown as dissolved metal and correspond to a total hardness of 100 mg/L and a water effect ratio of 1.0.

f. Freshwater aquatic life criteria forpentachlorophenol are expressed as a function of pH, and are calculated as follows.Values displayed above in the matrix correspond to a pH of 7.8.
CMC = exp(1.005(pH)

¥ 4.830) CCC = exp(1.005(pH)

¥ 5.290)g. Aquatic life criteria for these compounds were issued in 1980 utilizing the 1980 Guidelines for criteria development. The acute values shown are final acute values(FAV) which by the 1980 Guidelines are instantaneous values as contrasted with a CMC which is a one-hour average.

h. These totals simply sum the criteria in each column. For aquatic life, there are 31 priority toxic pollutants with some type offreshwater or saltwater, acute or chronic criteria. For human health, there are 85 priority toxic pollutants with either ‘‘water + fish’’ or ‘‘fish only’’ criteria. Note that these totals count chromium as one pollutant even though EPA has developed criteria based on two valence states. In the matrix, EPA has assigned numbers 5a and 5b to the criteria for chromium to reflect the fact that the list of 126 priority toxic pollutants includes only a single listing for chromium.

i. If the CCC for total mercury exceeds 0.012 μ g/l more than once in a 3-year period in the ambient water, the edible portion of aquatic species of concern must be analyzed to determine whether the concentration of methyl mercury exceeds the FDA action level (1.0 mg/kg). If the FDA action level isexceeded, the State must notify the appropriate EPA Regional Administrator, initiate a revision of its mercury criterion in itswater quality standards so as to protect designated uses, and take other appropriate action such as issuance of a fish consumption advisory for the affected area.

j. No criteria for protection of humanhealth from consumption of aquatic organisms (excluding water) was presented in the 1980 criteria document or in the 1986 Quality Criteria for Water. Nevertheless, sufficientinformation was presented in the 1980 document to allow a calculation of a criterion, even though the results of such a calculation were not shown in the document.

k. The criterion for asbestos is the MCL (56 FR 3526, January 30, 1991).

l. [Reserved: This letter not used as a footnote.]

m. Criteria for these metals are expressed as a function of the water effect ratio, WER, as defined in 40 CFR 131.36(c).

CMC = column B1 or C1 value × WER CCC = column B2 or C2 value × WER n. EPA is not promulgating human healthcriteria for this contaminant. However, permit authorities should address this contaminant in NPDES permit actions using the State’s existing narrative criteria for toxics.

o. [Reserved: This letter not used as a footnote.]

p. Criterion expressed as total recoverable. q. This criterion applies to total PCBs ( e.g.,the sum of all congener or isomer or homolog or Aroclor analyses).

G ENERAL N OTES
1. This chart lists all of EPA’s prioritytoxic pollutants whether or not criteria recommendations are available. Blank spacesindicate the absence of criteria recommendations. 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. EPA has addedthe Chemical Abstracts Service (CAS) registry numbers, which provide a unique identification for each chemical.

2. The following chemicals have organoleptic based criteria recommendationsthat are not included on this chart (for reasons which are discussed in the preamble): copper, zinc, chlorobenzene, 2-chlorophenol, 2,4-dichlorophenol, acenaphthene, 2,4- dimethylphenol, 3-methyl-4-chlorophenol, hexachlorocyclopentadiene, pentachlorophenol, phenol.

3. For purposes of this rulemaking, freshwater criteria and saltwater criteria apply as specified in 40 CFR 131.36(c).

N OTE TO PARAGRAPH (b)(1): On April 14, 1995, the Environmental Protection Agency


## 486 40 CFR Ch. I (7–1–10 Edition) § 131.36

issued a stay of certain criteria in paragraph (b)(1) of this section as follows: the criteria in columns B and C for arsenic, cadmium, chromium (VI), copper, lead, nickel, silver,and zinc; the criteria in B1 and C1 for mercury; the criteria in column B for chromium(III); and the criteria in column C for selenium. The stay remains in effect until further notice. (2) Factors for Calculating Hardness-Dependent, Freshwater Metals Criteria

CMC=WER exp { m A [ln(hardness)]+b A } ×

Acute Conversion Factor CCC=WER exp { m C [ln(hardness)]+b C } ×

Chronic Conversion Factor
Final CMC and CCC values should be rounded

to two significant figures.

Metal m A b A m C b C Freshwater conversion factors

Acute Chronic

Cadmium ............................................... 1.128 –3.828 0.7852 –3.490 a 0.944 a 0.909 Chromium (III) ....................................... 0.8190 3.688 0.8190 1.561 0.316 0.860 Copper .................................................. 0.9422 –1.464 0.8545 –1.465 0.960 0.960 Lead ...................................................... 1.273 -1.460 1.273 –4.705 a 0.791 a 0.791 Nickel .................................................... 0.8460 3.3612 0.8460 1.1645 0.998 0.997 Silver ..................................................... 1.72 –6.52 b N/A b N/A 0.85 b N/A Zinc ....................................................... 0.8473 0.8604 0.8473 0.7614 0.978 0.986

Note to table: The term ‘‘exp’’ represents the base e exponential function. Footnotes to table:

a The freshwater conversion factors (CF) for cadmium and lead are hardness-dependent and can be calculated for any hardness [see limitations in § 131.36(c)(4)] using the following equations:

Cadmium Acute: CF=1.136672—[(ln hardness)(0.041838)] Chronic: CF=1.101672—[(ln hardness)(0.041838)] Lead (Acute and Chronic): CF = 1.46203—[(ln hardness)(0.145712)]

b No chronic criteria are available for silver.

(c) Applicability. (1) The criteria in paragraph (b) of this section apply to the States’ designated uses cited in paragraph (d) of this section and supersede any criteria adopted by the State, except when State regulations contain criteria which are more stringent for a particular use in which case the State’s criteria will continue to apply.

(2) The criteria established in this sectionare subject to the State’s general rules of applicability in the same way and to the sameextent as are the other numeric toxics criteria when applied to the same use classifications including mixing zones, and low flow values below which numeric standards can be exceeded in flowing fresh waters.

(i) For all waters with mixing zone regulations or implementation procedures, the criteria apply at the appropriate locations within or at the boundary of the mixingzones; otherwise the criteria apply throughout the waterbody including at the end of any discharge pipe, canal or other discharge point.

(ii) A State shall not use a low flow valuebelow which numeric standards can be exceeded that is less stringent than the following for waters suitable for the establishment of low flow return frequencies (i.e., streams and rivers):

A QUATIC L IFE Acute criteria (CMC) 1 Q 10 or 1 B 3 Chronic criteria

(CCC) 7 Q 10 or 4 B 3

H UMAN H EALTH Non-carcinogens 30 Q 5 Carcinogens Harmonic mean flow

Where:

CMC—criteria maximum concentration—the

water quality criteria to protect against acute effects in aquatic life and is thehighest instream concentration of a priority toxic pollutant consisting of a onehour average not to be exceeded more than once every three years on the average; CCC—criteria continuous concentration—the

water quality criteria to protect againstchronic effects in aquatic life is the highest instream concentration of a prioritytoxic pollutant consisting of a 4-day average not to be exceeded more than once every three years on the average;1 Q 10 is the lowest one day flow with an average recurrence frequency of once in 10 years determined hydrologically; 1 B 3 is biologically based and indicates an

allowable exceedence of once every 3 years. It is determined by EPA’s computerized method (DFLOW model); 7 Q 10 is the lowest average 7 consecutive day

low flow with an average recurrence frequency of once in 10 years determined hydrologically; 4 B 3 is biologically based and indicates an

allowable exceedence for 4 consecutive days once every 3 years. It is determined by EPA’s computerized method (DFLOW model); 30 Q 5 is the lowest average 30 consecutive

day low flow with an average recurrence frequency of once in 5 years determined hydrologically; and the harmonic mean


## 487 Environmental Protection Agency § 131.36

flow is a long term mean flow value calculated by dividing the number of dailyflows analyzed by the sum of the reciprocals of those daily flows.



### (iii) If a State does not have such a low flow value for numeric standards compliance, then none shall apply and the criteria included in paragraph (d) of this section herein apply at all flows.

(3) The aquatic life criteria in the matrix in paragraph (b) of this section apply as follows:

(i) For waters in which the salinity isequal to or less than 1 part per thousand 95% or more of the time, the applicable criteria are the freshwater criteria in Column B;

(ii) For waters in which the salinity is equal to or greater than 10 parts per thousand 95% or more of the time, the applicable criteria are the saltwater criteria in Column C; and

(iii) For waters in which the salinity is between 1 and 10 parts per thousand as defined in paragraphs (c)(3) (i) and(ii) of this section, the applicable criteria are the more stringent of thefreshwater or saltwater criteria. However, the Regional Administrator may approve the use of the alternativefreshwater or saltwater criteria if scientifically defensible information anddata demonstrate that on a site-specific basis the biology of the waterbody is dominated by freshwater aquatic life and that freshwater criteria are more appropriate; or conversely, the biologyof the waterbody is dominated by saltwater aquatic life and that saltwater criteria are more appropriate.

(4) Application of metals criteria. (i) For purposes of calculating freshwater aquatic life criteria for metals from the equations in paragraph (b)(2) ofthis section, the minimum hardness allowed for use in those equations shall not be less than 25 mg/l, as calcium carbonate, even if the actual ambient hardness is less than 25 mg/l as calcium carbonate. The maximum hardness value for use in those equations shallnot exceed 400 mg/l as calcium carbonate, even if the actual ambient hardness is greater than 400 mg/l ascalcium carbonate. The same provisions apply for calculating the metals criteria for the comparisons provided for in paragraph (c)(3)(iii) of this section.

(ii) The hardness values used shall be consistent with the design discharge conditions established in paragraph(c)(2) of this section for flows and mixing zones.

(iii) Except where otherwise noted, the criteria for metals (compounds #2, #4–# 11, and #13, in paragraph (b) of this section) are expressed as dissolved metal. For purposes of calculating aquatic life criteria for metals fromthe equations in footnote m. in the criteria matrix in paragraph (b)(1) of thissection and the equations in paragraphs (b)(2) of this section, the watereffect ratio is computed as a specific pollutant’s acute or chronic toxicity values measured in water from the site covered by the standard, divided by the respective acute or chronic toxicity value in laboratory dilution water.

(d) Criteria for Specific Jurisdictions — (1) Rhode Island, EPA Region 1. (i) All waters assigned to the following use classifications in the Water QualityRegulations for Water Pollution Control adopted under Chapters 46–12, 42– 17.1, and 42–35 of the General Laws of Rhode Island are subject to the criteria in paragraph (d)(1)(ii) of this section, without exception:

6.21 Freshwater 6.22 Saltwater: Class A .................... Class SA Class B .................... Class SB Class C .................... Class SC



### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classifications identified in paragraph (d)(1)(i) of this section:

Use classification Applicable criteria

Class A .................................. Class B waters where water

supply use is designated These classifications are assigned the criteria in Column D1—#2, 68 Class B waters where water

supply use is not designated. Class C; Class SA; Class SB; Class SC Each of these classifications is assigned the criteria in: Column D2—#2, 68



### (iii) The human health criteria shall be applied at the 10

¥ 5 

### risk level, consistent with the State policy. To determine appropriate value for carcinogens, see footnote c in the criteria matrix in paragraph (b)(1) of this section.


## 488 40 CFR Ch. I (7–1–10 Edition) § 131.36

(2) Vermont, EPA Region 1. (i) All waters assigned to the following use classifications in the Vermont Water Quality Standards adopted under the authority of the Vermont Water Pollution Control Act (10 V.S.A., Chapter 47) are subject to the criteria in paragraph(d)(2)(ii) of this section, without exception: Class A
Class B
Class C



### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classifications identified in paragraph (d)(2)(i) of this
section:

Use classification Applicable criteria

1. Classes A1, A2, B1, B2, B3 .................................................... These classification are assigned the criterio n in: Column B2—#105.



### (iii) The human health criteria shall be applied at the State-proposed 10

¥ 6 

### risk level.

(3) New Jersey, EPA Region 2. (i) All waters assigned to the following useclassifications in the New Jersey Administrative Code (N.J.A.C.) 7:9–4.1 et seq., Surface Water Quality Standards, are subject to the criteria in paragraph(d)(3)(ii) of this section, without exception.

N.J.A.C. 7:9–4.12(b): Class PL N.J.A.C. 7:9–4.12(c): Class FW2 N.J.A.C. 7:9–4.12(d): Class SE1 N.J.A.C. 7:9–4.12(e): Class SE2 N.J.A.C. 7:9–4.12(f): Class SE3 N.J.A.C. 7:9–4.12(g): Class SC N.J.A.C. 7:9–4.13(a): Delaware River Zones 1C, 1D, and 1E N.J.A.C. 7:9–4.13(b): Delaware River Zone 2 N.J.A.C. 7:9–4.13(c): Delaware River Zone 3 N.J.A.C. 7:9–4.13(d): Delaware River Zone 4 N.J.A.C. 7:9–4.13(e): Delaware River Zone 5 N.J.A.C. 7:9–4.13(f): Delaware River Zone 6



### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classifications identified in paragraph (d)(3)(i) of this section:

Use classification Applicable criteria

1. Freshwater Pinelands, FW2 .................................................... These classifications are each assigned the cri teria in: i. Column B1—#2, 4, 5a, 5b, 6–11, 13. ii. Column B2—#2, 4, 5a, 5b, 6–10, 13. iii. Column D1—#125b at a 10

¥ 6 risk level. iv. Column D2—#125b at a 10

¥ 6 risk level. v. Column D2—#23, 30, 37, 42, 87, 89, 93 and 105 at a 10

¥ 5

risk level. 2. PL (Saline Water Pinelands), SE1, SE2, SE3, SC, Delaware

Bay Zone 6. These classifications are each assigned the criteria in:

i. Column C1—#2, 4, 5b, 6–11, 13. ii. Column C2—#2, 4, 5b, 6–10, 13. iii. Column D1—#125b at a 10

¥ 6 risk level. iv. Column D2—#125b at a 10

¥ 6 risk level. v. Column D2—#23, 30, 37, 42, 87, 89, 93 and 105 at a 10

¥ 5

risk level. 3. Delaware River Zones 1C, 1D, 1E, 2, 3, 4, and 5 ................. i. Column B1—none. ii. Column B2—none. iii. Column D1—none. iv. Column D2—none. 4. Delaware River Zones 3, 4, and 5 .......................................... These classifications are each assigned the criter ia in: i. Column C1—none. ii. Column C2—none. iii. Column D2—none.



### (iii) The human health criteria shall be applied at the State-proposed 10

¥ 6 

### risk level for EPA rated Class A, B 1 

### , and B 2 

### carcinogens; EPA rated Class C carcinogens shall be applied at 10

¥ 5 

### risk level. To determine appropriate value for carcinogens, see footnote c. in the matrix in paragraph (b)(1) of this
section.

(4) Puerto Rico, EPA Region 2. (i) All waters assigned to the following use classifications in the Puerto Rico


## 489 Environmental Protection Agency § 131.36

Water Quality Standards (promulgated by Resolution Number R–83–5–2) are subject to the criteria in paragraph (d)(4)(ii) of this section, without exception.

Article 2.2.2—Class SB Article 2.2.3—Class SC Article 2.2.4—Class SD



### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classifications identified in paragraph (d)(4)(i) of this
section:

Use classification Applicable criteria

Class SD ...................................................................................... Column B1—# 118. Column B2—#s 8, 105, 115, 118, 119, 120, 121, 122, 123,124,

125a, 125b. Column D1—#s 12, 16, 27, 60, 61, 62, 64, 73, 74, 92, 93, 103,

104, 114, 116, 118, 119, 120, 121, 122, 123, 124, 125a, 125b. Class SB, Class SC .................................................................... Column C1—#s 5b, 112, 113, 118. Column C2—#s 5b, 8, 112, 113, 118, 119, 120, 121, 122, 123,

124, 125a, 125b. Column D2—#s 12, 16, 27, 60, 61, 62, 64, 73, 74, 87, 92, 93,

103, 104, 114, 116, 118, 119, 120, 121, 122, 123, 124, 125a, 125b.



### (iii) The human health criteria shall be applied at the State-proposed 10

¥ 5 

### risk level. To determine appropriate value for carcinogens, see footnote c, in the criteria matrix in paragraph (b)(1) of this section.

(5) District of Columbia, EPA Region 3. (i) All waters assigned to the following use classifications in chapter 11 Title 21 DCMR, Water Quality Standards of the District of Columbia are subject to the criteria in paragraph (d)(5)(ii) of this section, without exception:

1101.2 Class C waters



### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classification identified in paragraph (d)(5)(i) of this section:

Use classification Applicable criteria

1. Class C .................................................................................... This classification is assigned t he additional criteria in: Column B2; #10, 118, 126.



### (iii) The human health criteria shall be applied at the State-adopted 10

¥ 6 

### risk level.

(6) Florida, EPA Region 4. (i) All waters assigned to the following use classifications in Chapter 17–301 of theFlorida Administrative Code (i.e., identified in Section 17–302.600) are subject to the criteria in paragraph (d)(6)(ii) of this section, without exception: Class I
Class II
Class III



### (ii) The following criteria from the matrix paragraph (b)(1) of this sectionapply to the use classifications identified in paragraph (d)(6)(i) of this section:

Use classification Applicable criteria

Class I .......................................................................................... This classification is assigne d the criteria in:
Column D1—#16
Class II ......................................................................................... Class III (marine) ......................................................................... This classification is assigned the criteria in:

Column D2—#16 Class III (freshwater) ................................................................... This classification is assigned the cr iteria in:
Column D2—#16


## 490 40 CFR Ch. I (7–1–10 Edition) § 131.36

(iii) The human health criteria shall be applied at the State-adopted 10

¥ 6 

### risk level.

(7)–(8) [Reserved] (9) Kansas, EPA Region 7. (i) All waters assigned to the following use classification in the Kansas Department of Health and Environment regulations, K.A.R. 28–16–28b through K.A.R. 28–16–28f, are subject to the criteria in paragraph (d)(9)(ii) of this section, without exception. Section (2)(A)—Special Aquatic Life Use Waters Section (2)(B)—Expected Aquatic Life Use
Waters Section (2)(C)—Restricted Aquatic Life Use
Waters Section (3)—Domestic Water Supply. Section (4)—Food Procurement Use.



### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classifications identified in paragraph (d)(9)(i) of this section:

Use classification Applicable criteria

1. Sections (2)(A), (2)(B), (2)(C), (4) ........................................... These classifications are each assigned crite ria as follows: i. Column B1, #2. ii. Column D2, #12, 21, 29, 39, 46, 68, 79, 81, 86, 93, 104,

114, 118. 2. Section (3) ............................................................................... This classification is assigned al l criteria in: Column D1, all except #1, 9, 12, 14, 15, 17, 22, 33, 36, 39, 44,

75, 77, 79, 90, 112, 113, and 115.



### (iii) The human health criteria shall be applied at the State-adopted 10

¥ 6 

### risk level.

(10) California, EPA Region 9. (i) All waters assigned any aquatic life or human health use classifications in the Water Quality Control Plans for the various Basins of the State (‘‘Basin Plans’’), as amended, adopted by theCalifornia State Water Resources Control Board (‘‘SWRCB’’), except for ocean waters covered by the Water Quality Control Plan for Ocean Waters of California (‘‘Ocean Plan’’) adopted by the SWRCB with resolution Number 90–27 on March 22, 1990, are subject to the criteria in paragraph (d)(10)(ii) of this section, without exception. Thesecriteria amend the portions of the existing State standards contained in the Basin Plans. More particularly these criteria amend water quality criteria contained in the Basin Plan Chapters specifying water quality objectives (the State equivalent of federal waterquality criteria) for the toxic pollutants identified in paragraph (d)(10)(ii) of this section. Although the State has adopted several use designations for each of these waters, for purposes of this action, the specific standards to be applied in paragraph (d)(10)(ii) of this section are based on the presence in all waters of some aquatic life designation and the presence or absence of the MUN use designation (Municipal and domestic supply). (See Basin Plans for more detailed use definitions.)

(ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the water and use classifications defined in paragraph (d)(10)(i) of this section and identified below:

Water and use classification Applicable criteria

Waters of the State defined as bays or estuaries except the

Sacramento-San Joaquin Delta and San Francisco Bay These waters are assigned the criteria in:

Column B1—pollutants 5a

and 14 Column B2—pollutants 5a

and 14 Column C1—pollutant 14 Column C2—pollutant 14 Column D2—pollutants 1,

12, 17, 18, 21, 22, 29, 30, 32, 33, 37, 38, 42–44, 46, 48, 49, 54, 59, 66, 67, 68, 78–82, 85, 89, 90, 91, 93, 95, 96, 98


## 491 Environmental Protection Agency § 131.36

Water and use classification Applicable criteria

Waters of the Sacramento—San Joaquin Delta and waters of

the State defined as inland (i.e., all surface waters of the State not bays or estuaries or ocean) that include a MUN use designation These waters are assigned the criteria in:

Column B1—pollutants 5a

and 14 Column B2—pollutants 5a

and 14 Column D1—pollutants 1,

12, 15, 17, 18, 21, 22, 29, 30, 32, 33, 37, 38, 42–48, 49, 59, 66, 67, 68, 78–82, 85, 89, 90, 91, 93, 95, 96, 98
Waters of the State defined as inland without an MUN use

designation These waters are assigned the criteria in:

Column B1—pollutants 5a

and 14 Column B2—pollutants 5a

and 14 Column D2—pollutants 1,

12, 17, 18, 21, 22, 29, 30, 32, 33, 37, 38, 42–44, 46, 48, 49, 54, 59, 66, 67, 68, 78–82, 85, 89, 90, 91, 93, 95, 96, 98 Waters of the San Joaquin River from the mouth of the

Merced River to Vernalis In addition to the criteria assigned to these waters elsewhere in this rule, these waters are assigned the criteria in:

Column B2—pollutant 10Waters of Salt Slough, Mud Slough (north) and the San Joaquin River, Sack Dam to the mouth of the Merced River In addition to the criteria assigned to these waters elsewhere in this rule, these waters are assigned the criteria in:

Column B1—pollutant 10 Column B2—pollutant 10 Waters of San Francisco Bay upstream to and including

Suisun Bay and the Sacramento-San Joaquin Delta These waters are assigned the criteria in:

Column B1—pollutants 5a,

10* and 14 Column B2—pollutants 5a,

10* and 14 Column C1—pollutant 14 Column C2—pollutant 14 Column D2—pollutants 1,

12, 17, 18, 21, 22, 29, 30, 32, 33, 37, 38, 42–44, 46, 48, 49, 54, 59, 66, 67, 68, 78–82, 85, 89, 90, 91, 93, 95, 96, 98 All inland waters of the United States or enclosed bays and

estuaries that are waters of the United States that includean MUN use designation and that the State has either excluded or partially excluded from coverage under its WaterQuality Control Plan for Inland Surface Waters of California, Tables 1 and 2, or its Water Quality Control Plan for Enclosed Bays and Estuaries of California, Tables 1 and 2, or has deferred applicability of those tables. (Category (a), (b), and (c) waters described on page 6 of Water Quality Control Plan for Inland Surface Waters of California or page 6 of its Water Quality Control Plan for Enclosed Bays and Estuaries of California.) These waters are assigned the criteria for pollutants for which the State does notapply Table 1 or 2 standards. These criteria are:

Column B1—all pollutants Column B2—all pollutants Column D1—all pollutants

except #2


## 492 40 CFR Ch. I (7–1–10 Edition) § 131.36

Water and use classification Applicable criteria

All inland waters of the United States that do not include an

MUN use designation and that the State has either excluded or partially excluded from coverage under its WaterQuality Control Plan for Inland Surface Waters of California, Tables 1 and 2, or has deferred applicability of these tables. (Category (a), (b), and (c) waters described on page 6 of Water Quality Control Plan for Inland Surface Waters of California.) These waters are assigned the criteria for pollutants for which the State does notapply Table 1 or 2 standards. These criteria are:

Column B1—all pollutants Column B2—all pollutants Column D2—all pollutants

except #2 All enclosed bays and estuaries that are waters of the United

States that do not include an MUN designation and that the State has either excluded or partially excluded from coverage under its Water Quality Control Plan for Inland Surface Waters of California, Tables 1 and 2, or its Water Quality Control Plan for Enclosed Bays and Estuaries of California, Tables 1 and 2, or has deferred applicability of those tables. (Category (a), (b), and (c) waters described on page 6 of Water Quality Control Plan for Inland Surface Waters of California or page 6 of its Water Quality Control Plan for Enclosed Bays and Estuaries of California.) These waters are assigned the criteria for pollutants for which the State does notapply Table 1 or 2 standards. These criteria are:

Column B1—all pollutants Column B2—all pollutants Column C1—all pollutants Column C2—all pollutants Column D2—all pollutants

except #2 *The fresh water selenium criteria are included for the San Francisco Bay estuary becausehigh levels of bioaccumulation of selenium in the estuary indicate that the salt water criteria are underprotective for San Francisco Bay.



### (iii) The human health criteria shall be applied at the State-adopted 10

¥ 6 

### risk level.

(11) Nevada, EPA Region 9. (i) All waters assigned the use classifications inChapter 445 of the Nevada Administrative Code (NAC), Nevada Water Pollution Control Regulations, which are referred to in paragraph (d)(11)(ii) of this section, are subject to the criteria in paragraph (d)(11)(ii) of this section, without exception. These criteria amend the existing State standards contained in the Nevada Water Pollution Control Regulations. More particularly, these criteria amend or supplement the table of numeric standards in NAC 445.1339 for the toxic pollutants identified in paragraph (d)(11)(ii) of this section.

(ii) The following criteria from matrix in paragraph (b)(1) of this sectionapply to the waters defined in paragraph (d)(11)(i) of this section and identified below:

Water and use classification Applicable criteria

Waters that the State has included in NAC

445.1339 where Municipal or domestic supply is a designated use These waters are assigned the criteria in: Column B1—pollutant #118 Column B2—pollutant #118 Column D1—pollutants #15, 16, 18, 19, 20,

21, 23, 26, 27, 29, 30, 34, 37, 38, 42, 43, 55, 58–62, 64, 66, 73, 74, 78, 82, 85, 87–89, 91, 92, 96, 98, 100, 103, 104, 105, 114, 116, 117, 118 Waters that the State has included in NAC

445.1339 where Municipal or domestic supply is not a designated use These waters are assigned the criteria in: Column B1—pollutant #118 Column B2—pollutant #118 Column D2—all pollutants except #2.



### (iii) The human health criteria shall be applied at the 10

¥ 5 

### risk level, consistent with State policy. To determine appropriate value for carcinogens, see footnote c in the criteria matrix in paragraph (b)(1) of this section. (12) Alaska, EPA Region 10. (i) All waters assigned to the following use classifications in the Alaska Administrative Code (AAC), Chapter 18 (i.e., identified in 18 AAC 70.020) are subject to the criteria in paragraph (d)(12)(ii) of this section, without exception:


## 493 Environmental Protection Agency § 131.37

70.020.(1) (A) Fresh Water 70.020.(1) (A) Water Supply

(i) Drinking, culinary, and food processing, (iii) Aquaculture; 70.020.(1) (B) Water Recreation

(i) Contact recreation, (ii) Secondary recreation; 70.020.(1) (C) Growth and propagation of fish, shellfish, other aquatic life, and wildlife 70.020.(2) (A) Marine Water 70.020.(2) (A) Water Supply

(i) Aquaculture, 70.020.(2) (B) Water Recreation (i) contact recreation, (ii) secondary recreation; 70.020.(2) (C) Growth and propagation of fish, shellfish, other aquatic life, and wildlife; 70.020.(2) (D) Harvesting for consumption of raw mollusks or other raw aquatic life.


### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classifications identified in paragraph (d)(12)(i) of this section:

Use classification Applicable criteria

(1)(A)(i) ........................................................................................ Column D1—#s 16, 18–21, 23, 26 , 27, 29, 30, 32, 37, 38, 42– 44, 53, 55, 59–62, 64, 66, 68, 73, 74, 78, 82, 85, 88, 89, 91–93, 96, 98, 102–105, 107–111, 117–126. (1)(A)(iii) ....................................................................................... Column D2—#s 14, 16, 18–21, 2 2, 23, 26, 27, 29, 30, 32, 37, 38, 42–44, 46, 53, 54, 55, 59–62, 64, 66, 68, 73, 74, 78, 82, 85, 88–93, 95, 96, 98, 102–105, 107–111, 115–126. (1)(B)(i), (1)(B)(ii), (1)(C) ............................................................. Column D2—#s 14, 16, 18–21, 22, 23, 2 6, 27, 29, 30, 32, 37, 38, 42–44, 46, 53, 54, 55, 59–62, 64, 66, 68, 73, 74, 78, 82, 85, 88–93, 95, 96, 98, 102–105, 107–111, 115–126. (2)(A)(i), (2)(B)(i), and (2)(B)ii, (2)(C), (2)(D) .............................. Column D2—#s 14, 16, 18–21, 22, 23, 26, 27, 29, 30, 32, 37, 38, 42–44, 46, 53, 54, 55, 59–62, 64, 66, 68, 73, 74, 78, 82, 85, 88–93, 95, 96, 98, 102–105, 107–111, 115–126.



### (iii) The human health criteria shall be applied at the State-proposed risk level of 10

¥ 5 

### . To determine appropriate value for carcinogens, see footnote c in the criteria matrix in paragraph (b)(1) of this section.

(13) [Reserved] (14) Washington, EPA Region 10. (i) All waters assigned to the following useclassifications in the Washington Administrative Code (WAC), Chapter 173– 201 (i.e., identified in WAC 173–201–045) are subject to the criteria in paragraph (d)(14)(ii) of this section, without exception:

173–201–045

Fish and Shellfish
Fish Water Supply (domestic)
Recreation



### (ii) The following criteria from thematrix in paragraph (b)(1) of this section apply to the use classifications identified in paragraph (d)(14)(i) of this section:

Use classification Applicable criteria

Fish and Shellfish; Fish ............................................................... These classifications are assigned the c riteria in: Column D2— all. Water Supply (domestic) ............................................................. These classifications are assigned the crit eria in: Column D1— all. Recreation ................................................................................... This classification is assigned th e criteria in: Column D2—Marine waters and freshwaters not protected for domestic water supply.



### (iii) The human health criteria shall be applied at the State proposed risk level of 10

¥ 6



### .
[57 FR 60910, Dec. 22, 1992]

E DITORIAL N OTE : For F EDERAL R EGISTER citations affecting §131.36, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume
and on GPO Access. 

### § 131.37 California.
(a) Additional criteria. The followingcriteria are applicable to waters specified in the Water Quality Control Plan for Salinity for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary, adopted by the California State Water Resources Control Board in State Board Resolution No. 91–34 on May 1, 1991: