1. (1) The U.S. Environmental Protection Agency has listed the chemical constituents given in Table 1 of this rule as toxic pollutants pursuant to Section 307(a)(1) of the Federal Water Pollution Control Act (FWPCA). Concentrations of these toxic pollutants in State waters shall not exceed the criteria indicated in Table 1 of this rule to the extent commensurate with the designated usage of such waters.

   1. (a) The freshwater and marine aquatic life criteria for certain pollutants are dependent on hardness or pH. For these pollutants, the criteria are given by the following equations. In the hardness-dependent equations for metals, a conversion factor converts the total recoverable value to a criterion expressed as the dissolved fraction in the water column. All numeric values listed for metals in Table 1 of this rule are expressed as dissolved metals unless otherwise noted.

      1. 1. Cadmium

         1. (i) freshwater acute aquatic life:

            conc. (μg/l) = (e(0.9789 [ln(hardness in mg/l as CaCO3)]-3.866)(CF); (Eq. 1) 

            conversion factor (CF) = 1.136672 - [ln(hardness)(0.041838)]

         2. (ii) freshwater chronic aquatic life:

            conc. (μg/l) = (e(0.7977 [ln(hardness in mg/l as CaCO3)]-3.909)(CF); (Eq. 2) 

            conversion factor (CF) = 1.101672 - [ln(hardness)(0.041838)]

      2. 2. Chromium (trivalent)

         1. (i) freshwater acute aquatic life:

            conc. (μg/l) = (e(0.8190[ln(hardness in mg/l as CaCO3)]+3.7256)(CF); (Eq. 3)

            conversion factor (CF) = 0.316

         2. (ii) freshwater chronic aquatic life:

            conc. (μg/l) = (e(0.8190[ln(hardness in mg/l as CaCO3)]+0.6848)(CF); (Eq. 4)

            conversion factor (CF) = 0.860

      3. 3. Copper

         1. (i) freshwater acute aquatic life:

            conc. (μg/l) = (e(0.9422[ln(hardness in mg/l as CaCO3)]-1.700)(CF); (Eq. 5)

            conversion factor (CF) = 0.960

         2. (ii) freshwater chronic aquatic life:

            conc. (μg/l) = (e(0.8545[ln(hardness in mg/l as CaCO3)]-1.702)(CF); (Eq. 6)

            conversion factor (CF) = 0.960

      4. 4. Lead

         1. (i) freshwater acute aquatic life:

            conc. (μg/l) = (e(1.273[ln(hardness in mg/l as CaCO3)]-1.460)(CF); (Eq. 7)

            conversion factor (CF) = 1.46203 - [ln(hardness)(0.145712)]

         2. (ii) freshwater chronic aquatic life:

            conc. (μg/l) = (e(1.273[ln(hardness in mg/l as CaCO3)]-4.705)(CF); (Eq. 8)

            conversion factor (CF) = 1.46203 - [ln(hardness)(0.145712)]

      5. 5. Nickel

         1. (i) freshwater acute aquatic life:

            conc. (μg/l) = (e(0.8460[ln(hardness in mg/l as CaCO3)]+2.255)(CF); (Eq. 9)

            conversion factor (CF) = 0.998

         2. (ii) freshwater chronic aquatic life:

            conc. (μg/l) = (e(0.8460[ln(hardness in mg/l as CaCO3)]+0.0584)(CF); (Eq. 10)

            conversion factor (CF) = 0.997

      6. 6. Pentachlorophenol

         1. (i) freshwater acute aquatic life:

            conc. μg/l = e[1.005(pH)-4.869] (Eq. 11)

         2. (ii) freshwater chronic aquatic life:

            conc. μg/l = e[1.005(pH)-5.134](Eq. 12)

      7. 7. Silver

         1. (i) freshwater acute aquatic life:

            conc. (μg/l) = (e(1.72[ln(hardness in mg/l as CaCO3)]-6.59)(CF); (Eq. 13)

            conversion factor (CF) = 0.85

      8. 8. Zinc

         1. (i) freshwater acute aquatic life:

            conc. (μg/l) = (e(0.8473[ln(hardness in mg/l as CaCO3)]+0.884)(CF); (Eq. 14)

            conversion factor (CF) = 0.978

         2. (ii) freshwater chronic aquatic life:

            conc. (μg/l) = (e(0.8473[ln(hardness in mg/l as CaCO3)]+0.884)(CF); (Eq. 15)

            conversion factor (CF) = 0.986

   2. (b) The marine aquatic life criteria apply to coastal waters, as identified in Rule 335-6-11-.02 of the Department's regulations. The acute aquatic life criteria apply to all waters of the State. The chronic aquatic life criteria apply only to waters classified Outstanding Alabama Water, Public Water Supply, Swimming and Other Whole Body Water-Contact Sports, Shellfish Harvesting, Fish and Wildlife, and Limited Warmwater Fishery, as identified in Rule 335-6-11-.02 of the Department's regulations.
   3. (c) For the purpose of establishing effluent limitations pursuant to Chapter 335-6-6 of the Department's regulations, the minimum 7-day low flow that occurs once in 10 years (7Q₁₀) shall be the basis for applying the chronic aquatic life criteria, except in coastal waters and as noted in Rule 335-6-10-.09(6), and the minimum 1-day low flow that occurs once in 10 years (1Q₁₀) shall be the basis for applying the acute aquatic life criteria, except in coastal waters and as noted in Rule 335-6-10-.09(7)(c)(5). Where a permit specifies a minimum flow greater than 7Q₁₀, the specified minimum flow may be used as the basis for applying the acute and chronic aquatic life criteria for that permit.

   4. (d) Except as noted in Table 1 of this rule, two human health criteria are provided for each pollutant--a criterion for consumption of water and fish, and a criterion for consumption of fish only. For certain pollutants, the human health criterion for consumption of water and fish may represent a maximum contaminant level (MCL) developed under the Safe Drinking Water Act.

      1. 1. For pollutants classified by the U.S. Environmental Protection Agency as non-carcinogens, the criteria shall be given by the following equations, except where numeric values are given in Table 1 of this rule.

         1. (i) Consumption of water and fish:

            conc. (mg/l) = (HBW x RfD x RSC)/[(FCR x BCF) + WCR] (Eq. 16)

         2. (ii) Consumption of fish only:

            conc. (mg/l) = (HBW x RfD x RSC)/(FCR x BCF) (Eq. 17)

            where (in Equations 16 and 17):

            HBW = human body weight, set at 70 kg

            RfD = reference dose, in mg/(kg-day)

            RSC = relative source contribution

            FCR = fish consumption rate, set at 0.030 kg/day

            BCF = bioconcentration factor, in l/kg

            WCR = water consumption rate, set at 2 l/day

         3. (iii) The values used for the reference dose (RfD) shall be values available through the U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS), and values used for the bioconcentration factor (BCF) and relative source contribution (RSC) shall be values contained in ambient water quality criteria documents published by the U.S. Environmental Protection Agency, except where other values are established pursuant to subparagraph (1)(g). The RfD, RSC, and BCF values for specific pollutants are provided in Appendix A.

      2. 2. For pollutants classified by the U.S. Environmental Protection Agency as carcinogens, the criteria shall be given by the following equations, except where numeric values are given in Table 1 of this rule.

         1. (i) Consumption of water and fish:

            conc. (mg/l) = (HBW x RL)/(CPF x [(FCR x BCF) + WCR]) (Eq. 18)

         2. (ii) Consumption of fish only:

            conc. (mg/l) = (HBW x RL)/(CPF x FCR x BCF) (Eq. 19)

            where (in Equations 18 and 19):

            HBW = human body weight, set at 70 kg

            RL = risk level, set at 1 x 10^-6 (except for arsenic which is set at 1 x 10^-5)

            CPF = cancer potency factor, in (kg-day)/mg

            FCR = fish consumption rate, set at 0.030 kg/day

            BCF = bioconcentration factor, in l/kg

            WCR = water consumption rate, set at 2 l/day

         3. (iii) The values used for the cancer potency factor (CPF) shall be values available through the U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS), and values used for the bioconcentration factor (BCF) shall be values contained in ambient water quality criteria documents published by the U.S. Environmental Protection Agency, except where other values are established pursuant to subparagraph (1)(g). The CPF and BCF values for specific pollutants are provided in Appendix A.
   5. (e) The criteria given in Table 1 of this rule for consumption of water and fish, or computed from equation 16 or equation 18 for consumption of water and fish, shall apply only to those waters of the State classified Public Water Supply, as identified in Rule 335-6-11-.02 of the Department's regulations. The criteria given in Table 1 of this rule for consumption of fish only, or computed from equation 17 or equation 19 for consumption of fish only, shall apply to all waters of the State.
   6. (f) For the purposes of establishing effluent limitations pursuant to Chapter 335-6-6 of the Department's regulations, the minimum 7-day low flow that occurs once in 10 years (7Q₁₀) shall be the basis for applying the human health criteria for pollutants classified as non-carcinogens, and the mean annual flow shall be the basis for applying the human health criteria for pollutants classified as carcinogens, except in coastal waters; except that where a permit specifies a minimum flow greater than 7Q₁₀, the specified minimum flow may be used as the basis for applying the human health criteria for pollutants classified as non-carcinogens for that permit.

   7. (g) Numeric criteria may be computed by the Department from equations 16, 17, 18, and 19 using values for the reference dose (RfD), relative source contribution (RSC), cancer potency factor (CPF), and bioconcentration factor (BCF) determined by the Department in consultation with the Alabama Department of Public Health after review of information available from sources other than the U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) or ambient water quality criteria documents. Such criteria, or the RfD, RSC, CPF, and BCF values used to compute criteria, shall not be effective until adopted following established rulemaking procedures.

      Table 1

      Toxic Pollutant Criteria

      		Aquatic Life Criteria (in µg/l unless otherwise noted)	Human Health Criteria (in µg/l unless otherwise noted)
      	Pollutant	Freshwater Acute	Freshwater Chronic	Marine Acute	Marine Chronic	Consumption of Water and Fish	Consumption of Fish Only
      Acenaphthene					Eq. 16	Eq. 17
      Acrolein	3	3			Eq. 16	Eq. 17
      Acrylonitrile 1					Eq. 18	Eq. 19
      Aldrin 1	3.0		1.3		Eq. 18	Eq. 19
      Anthracene					Eq. 16	Eq. 17
      Antimony					Eq. 16	Eq. 17
      Arsenic 1 (Risk level = 1 x 10‑5)	340 (tri)	150 (tri)	69 (tri)	36 (tri)	Eq. 18	Eq. 19
      Asbestos					7,000,000 fibers/l  (MCL)
      Benzene 1					Eq. 18	Eq. 19
      Benzidine 1					Eq. 18	Eq. 19
      Benzo(a)anthracene 1					Eq. 18	Eq. 19
      Benzo(a)pyrene 1					Eq. 18	Eq. 19
      Benzo(b)fluoranthene 1					Eq. 18	Eq. 19
      Benzo(k)fluoranthene 1					Eq. 18	Eq. 19
      Bis(2‑chloroethyl)ether 1					Eq. 18	Eq. 19
      Bis(2‑chloroisopropyl)ether					Eq. 16	Eq. 17
      Bis(2‑ethylhexyl)phthalate 1					Eq. 18	Eq. 19
      Bromoform 1					Eq. 18	Eq. 19
      Butylbenzyl phthalate					Eq. 16	Eq. 17
      Cadmium	Eq. 1	Eq. 2	33	7.9
      Carbaryl	2.1	2.1	1.6
      Carbon tetrachloride 1					Eq. 18	Eq. 19
      Chlordane 1	2.4	0.0043	0.09	0.004	Eq. 18	Eq. 19
      Chlorine	19	11	13	7.5
      Chlorobenzene					Eq. 16	Eq. 17
      Chlorodibromomethane 1					Eq. 18	Eq. 19
      Chloroform 1					Eq. 18	Eq. 19
      2‑Chloronaphthalene					Eq. 16	Eq. 17
      2‑Chlorophenol					Eq. 16	Eq. 17
      Chlorpyrifos	0.083	0.041	0.011	0.0056
      Chromium (trivalent)	Eq. 3	Eq. 4
      Chromium (hexavalent)	16	11	1100	50
      Chrysene 1					Eq. 18	Eq. 19
      Copper	Eq. 5	Eq. 6	4.8	3.1	1300 (MCL)
      Cyanide (free)	22	5.2	1.0	1.0	Eq. 16	Eq. 17
      4,4'‑DDD 1					Eq. 18	Eq. 19
      4,4'‑DDE 1					Eq. 18	Eq. 19
      4,4'‑DDT 1	1.1	0.001	0.13	0.001	Eq. 18	Eq. 19
      Diazinon	0.17	0.17	0.82	0.82
      Dibenzo(a,h)anthracene 1					Eq. 18	Eq. 19
      1,2‑Dichlorobenzene					Eq. 16	Eq. 17
      1,3‑Dichlorobenzene					Eq. 16	Eq. 17
      1,4‑Dichlorobenzene					Eq. 16	Eq. 17
      3,3'‑Dichlorobenzidine 1					Eq. 18	Eq. 19
      Dichlorobromomethane 1					Eq. 18	Eq. 19
      1,2‑Dichloroethane 1					Eq. 18	Eq. 19
      1,1‑Dichloroethylene					Eq. 16	Eq. 17
      2,4‑Dichlorophenol					Eq. 16	Eq. 17
      1,2 Dichloropropane 1					Eq. 18	Eq. 19
      1,3 Dichloropropylene 1					Eq. 18	Eq. 19
      Dieldrin 1	0.24	0.056	0.71	0.0019	Eq. 18	Eq. 19
      2,4‑Dimethylphenol					Eq. 16	Eq. 17
      Diethyl phthalate					Eq. 16	Eq. 17
      Dimethyl phthalate					Eq. 16	Eq. 17
      Di‑n‑butyl phthalate					Eq. 16	Eq. 17
      4,6‑Dinitro‑2‑methylphenol					Eq. 16	Eq. 17
      2,4 Dinitrotoluene 1					Eq. 18	Eq. 19
      2,4‑Dinitrophenol					Eq. 16	Eq. 17
      Dioxin (2,3,7,8‑TCDD) 1					Eq. 18	Eq. 19
      1,2‑Diphenylhydrazine 1					Eq. 18	Eq. 19
      Endosulfan (alpha)	0.22	0.056	0.034	0.0087	Eq. 16	Eq. 17
      Endosulfan (beta)	0.22	0.056	0.034	0.0087	Eq. 16	Eq. 17
      Endosulfan sulfate					Eq. 16	Eq. 17
      Endrin	0.086	0.036	0.037	0.0023	Eq. 16	Eq. 17
      Endrin aldehyde					Eq. 16	Eq. 17
      Ethylbenzene					Eq. 16	Eq. 17
      Fluoranthene					Eq. 16	Eq. 17
      Fluorene					Eq. 16	Eq. 17
      Heptachlor 1	0.52	0.0038	0.053	0.0036	Eq. 18	Eq. 19
      Heptachlor epoxide 1	0.52	0.0038	0.053	0.0036	Eq. 18	Eq. 19
      Hexachlorobenzene 1					Eq. 18	Eq. 19
      Hexachlorobutadiene 1					Eq. 18	Eq. 19
      Hexachlorocyclohexane (alpha) 1					Eq. 18	Eq. 19
      Hexachlorocyclohexane (beta) 1					Eq. 18	Eq. 19
      Hexachlorocyclohexane (gamma)	0.95		0.16		Eq. 16	Eq. 17
      Hexachlorocyclopentadiene					Eq. 16	Eq. 17
      Hexachloroethane 1					Eq. 18	Eq. 19
      Indeno (1,2,3‑cd) pyrene 1					Eq. 18	Eq. 19
      Isophorone 1					Eq. 18	Eq. 19
      Lead	Eq. 7	Eq. 8	210	8.1
      Malathion		0.1		0.1
      Mercury (total recoverable)	2.4	0.012	2.1	0.025	Eq. 16	Eq. 17
      Methoxychlor		0.03		0.03
      Methyl bromide					Eq. 16	Eq. 17
      Methylene chloride 1					Eq. 18	Eq. 19
      Mirex		0.001		0.001
      Nickel	Eq. 9	Eq. 10	74	8.2	Eq. 16	Eq. 17
      Nitrobenzene					Eq. 16	Eq. 17
      N‑Nitrosodimethylamine 1					Eq. 18	Eq. 19
      N‑Nitrosodi‑n‑propylamine 1					Eq. 18	Eq. 19
      N‑Nitrosodiphenylamine 1					Eq. 18	Eq. 19
      Parathion	0.065	0.013
      PCB‑1016 1,2		0.014		0.03	Eq. 18	Eq. 19
      PCB‑1221 1,2		0.014		0.03	Eq. 18	Eq. 19
      PCB‑1232 1,2		0.014		0.03	Eq. 18	Eq. 19
      PCB‑1242 1,2		0.014		0.03	Eq. 18	Eq. 19
      PCB‑1248 1,2		0.014		0.03	Eq. 18	Eq. 19
      PCB‑1254 1,2		0.014		0.03	Eq. 18	Eq. 19
      PCB‑1260 1,2		0.014		0.03	Eq. 18	Eq. 19
      Pentachlorophenol 1	Eq. 11	Eq. 12	13	7.9	Eq. 18	Eq. 19
      Phenol					Eq. 16	Eq. 17
      Pyrene					Eq. 16	Eq. 17
      Selenium3	20	5.0	290	71	Eq. 16	Eq. 17
      Silver	Eq. 13		1.9
      1,1,2,2‑Tetrachloroethane 1					Eq. 18	Eq. 19
      Tetrachloroethylene 1					Eq. 18	Eq. 19
      Thallium					Eq. 16	Eq. 17
      Toluene					Eq. 16	Eq. 17
      Toxaphene 1	0.73	0.0002	0.21	0.0002	Eq. 18	Eq. 19
      1,2‑Trans‑dichloroethylene					Eq. 16	Eq. 17
      Tributyltin (TBT)	0.46	0.072	0.42	0.0074
      1,2,4‑Trichlorobenzene					Eq. 16	Eq. 17
      1,1,2‑Trichloroethane 1					Eq. 18	Eq. 19
      Trichloroethylene 1					Eq. 18	Eq. 19
      2,4,6‑Trichlorophenol 1					Eq. 18	Eq. 19
      Vinyl chloride 1					Eq. 18	Eq. 19
      Zinc	Eq. 14	Eq. 15	90	81	Eq. 16	Eq. 17

      1  Pollutants considered by EPA to be carcinogenic.

      2 The criteria for Polychlorinated Biphenyls (PCBs) apply to total PCBs, which is defined as the sum of the seven particular Aroclors (1016, 1221, 1232, 1242, 1248, 1254, and 1260) listed in this table.

      3  The freshwater aquatic life criteria for selenium are expressed in terms of  total recoverable metal in the water column.

Author: James E. McIndoe, Chris L. Johnson

Statutory Authority: Code of Ala. 1975, §§22-22-9, 22-22A-5, 22-22A-6, 22-22A-8.

History: Originally Adopted January 24, 1990; Filed January 26 1990; effective March 2, 1990. Amended: Filed February 27, 1991; effective April 3, 1991. Amended: Filed April 23, 1992; effective May 28, 1992. Amended: Filed July 25, 1994; effective August 29, 1994. Amended (Table 1 also): Filed April 25, 1997; effective May 30, 1997. Amended: Filed August 3, 2000; effective September 7, 2000. Amended: Filed December 8, 2000; effective January 12, 2001. Amended: Filed December 10, 2004; effective January 14, 2005. Amended (Table I amended also): Filed August 17, 2005; effective September 21, 2005. Amended (Table I only): Filed April 24, 2007; effective May 29, 2007. Amended (Table 1 also): Filed April 22, 2008; effective May 27, 2008. Amended: Filed February 25, 2014; effective April 1, 2014. Amended: Filed December 7, 2016; effective February 3, 2017. Amended: Published April 30, 2025; effective June 14, 2025.