401 KAR 5:031. Surface water standards.

      RELATES TO: KRS 146.200-146.360, 146.410-146.535, 146.550-146.570, 146.600-146.619, 146.990, 224.01-010, 224.01-400, 224.16-050, 224.16-070, 224.70-100-224.70-140, 224.71-100-224.71-145, 224.73-100-224.73-120

      STATUTORY AUTHORITY: KRS 146.220, 146.241, 146.270, 146.410, 146.450, 146.460, 146.465, 224.10-100, 224.16-050, 224.16-060, 224.70-100, 224.70-110, 40 C.F.R. Part 131, 16 U.S.C. 1271 et seq., 1531 et seq., 33 U.S.C. 1311, 1313, 1314, 1341

      NECESSITY, FUNCTION, AND CONFORMITY: KRS 224.10-100 requires the Environmental and Public Protection Cabinet to develop and conduct a comprehensive program for the management of water resources and to provide for the prevention, abatement, and control of water pollution. This administrative regulation and 401 KAR 5:002, 5:026, 5:029, and 5:030 establish procedures to protect the surface waters of the commonwealth, and thus protect water resources. This administrative regulation establishes water quality standards which consist of designated legitimate uses of the surface waters of the commonwealth and the associated water quality criteria necessary to protect those uses. These water quality standards are minimum requirements that apply to all surface waters in the commonwealth of Kentucky in order to maintain and protect them for designated uses. These water quality standards are subject to periodic review and revision in accordance with federal and state laws.

      Section 1. Nutrient Limits. In lakes and reservoirs and their tributaries, and other surface waters where eutrophication problems may exist, nitrogen, phosphorus, carbon, and contributing trace element discharges shall be limited in accordance with:

      (1) The scope of the problem;

      (2) The geography of the affected area; and

      (3) Relative contributions from existing and proposed sources.

      Section 2. Minimum Criteria Applicable to All Surface Waters. (1) The following minimum water quality criteria are applicable to all surface waters including mixing zones, with the exception that toxicity to aquatic life in mixing zones shall be subject to the provisions of 401 KAR 5:029, Section 4. Surface waters shall not be aesthetically or otherwise degraded by substances that:

      (a) Settle to form objectionable deposits;

      (b) Float as debris, scum, oil, or other matter to form a nuisance;

      (c) Produce objectionable color, odor, taste, or turbidity;

      (d) Injure, are chronically or acutely toxic to or produce adverse physiological or behavioral responses in humans, animals, fish and other aquatic life;

      (e) Produce undesirable aquatic life or result in the dominance of nuisance species;

      (f) Cause fish flesh tainting. The concentration of all phenolic compounds which cause fish flesh tainting shall not exceed five (5) μg/l as an instream value;

      (g) Cause the following changes in radionuclides:

      1. The gross total alpha particle activity, including radium-226 but excluding radon and uranium, to exceed fifteen (15) pCi/l;

      2. Combined radium-226 and radium-228 to exceed five (5) pCi/l. Specific determinations of radium-226 and radium-228 are not necessary if dissolved gross alpha particle activity does not exceed five (5) pCi/l;

      3. The concentration of total gross beta particle activity to exceed fifty (50) pCi/l;

      4. The concentration of tritium to exceed 20,000 pCi/l;

      5. The concentration of total Strontium-90 to exceed eight (8) pCi/l;

      6. The concentration of uranium to exceed thirty (30) mg/l.

      (2) The water quality criteria for the protection of human health related to fish consumption in Table 1 of Section 6 of this administrative regulation are applicable to all surface water at the edge of the assigned mixing zones except for those points where water is withdrawn for domestic water supply use. The criteria are established to protect human health from the consumption of fish tissue, and shall not be exceeded. For those substances associated with a cancer risk, an acceptable risk level of no more than one (1) additional cancer case in a population of 1,000,000 people, or 1 x 10^-6 shall be utilized to establish the allowable concentration.

      Section 3. Use Designations and Associated Criteria. (1) Surface waters may be designated as having one (1) or more legitimate uses and associated criteria protective of those uses. Those uses are listed in 401 KAR 5:026. Nothing in this administrative regulation shall be construed to prohibit or impair the legitimate beneficial uses of these waters. The criteria in Sections 2, 4, 6, and 7 of this administrative regulation represent minimum conditions necessary to:

      (a) Protect surface waters for the indicated use; and

      (b) Protect human health from fish consumption.

      (2) On occasion, surface water quality may be outside of the limits established to protect designated uses because of natural conditions. If this occurs during periods when stream flows are below the flow that is used by the cabinet to establish effluent limitations for wastewater treatment facilities, a discharger shall not be considered a contributor to instream violations of water quality standards, if treatment results in compliance with permit requirements.

      (3) Stream flows for water quality-based permits. The following stream flows shall be utilized if deriving KPDES permit limitations to protect surface waters for the listed uses and purposes:

      (a) Aquatic life protection shall be 7Q₁₀;

      (b) Water-based recreation protection shall be 7Q₁₀;

      (c) Domestic water supply protection shall be determined at points of withdrawal as:

      1. The harmonic mean for cancer-linked substances; and

      2. 7Q₁₀ for noncancer-linked substances;

      (d) Human health protection from fish consumption and for changes in radionuclides shall be the harmonic mean; and

      (e) Protection of aesthetics shall be 7Q₁₀.

      Section 4. Aquatic Life. (1) Warm water aquatic habitat. The following parameters and associated criteria shall apply for the protection of productive warm water aquatic communities, fowl, animal wildlife, arboreous growth, agricultural, and industrial uses:

      (a) Natural alkalinity as CaCO₃ shall not be reduced by more than twenty-five (25) percent. If natural alkalinity is below twenty (20) mg/l CaCO₃, there shall not be a reduction below the natural level. Alkalinity shall not be reduced or increased to a degree which may adversely affect the aquatic community.

      (b) pH shall not be less than six and zero-tenths (6.0) nor more than nine and zero-tenths (9.0) and shall not fluctuate more than one and zero-tenths (1.0) pH unit over a period of twenty-four (24) hours.

      (c) Flow shall not be altered to a degree which will adversely affect the aquatic community.

      (d) Temperature shall not exceed thirty-one and seven-tenths (31.7) degrees Celsius (eighty-nine (89) degrees Fahrenheit).

      1. The normal daily and seasonal temperature fluctuations that existed before the addition of heat due to other than natural causes shall be maintained.

      2. The cabinet may determine allowable surface water temperatures on a site-specific basis utilizing available data which shall be based on the effects of temperature on the aquatic biota which utilize specific surface waters of the commonwealth and which may be affected by person-induced temperature changes. Effects on downstream uses will also be considered in determining site-specific temperatures. Values in the following table are guidelines for surface water temperature.

Month/Date	Period Average (°F)	Instantaneous Maximum (°F)
January 1-31	45	50
February 1-29	45	50
March 1-15	51	56
March 16-31	54	59
April 1-15	58	64
April 16-30	64	69
May 1-15	68	73
May 16-31	75	80
June 1-15	80	85
June 16-30	83	87
July 1-31	84	89
August 1-31	84	89
September 1-15	84	87
September 16-30	82	86
October 1-15	77	82
October 16-31	72	77
November 1-30	67	72
December 1-31	52	57

      3. A successful demonstration concerning thermal discharge limits carried out under Section 316(a) of the Clean Water Act shall constitute compliance with the temperature requirements of this subsection. A successful demonstration assures the protection and propagation of a balanced indigenous population of shellfish, fish and wildlife in or on the water into which the discharge is made.

      (e) Dissolved oxygen.

      1. Dissolved oxygen shall be maintained at a minimum concentration of five and zero tenths (5.0) mg/l daily average; the instantaneous minimum shall not be less than four and zero-tenths (4.0) mg/l.

      2. The dissolved oxygen concentration shall be measured at middepth in waters having a total depth of ten (10) feet or less and at representative depths in other waters.

      (f) Total dissolved solids or specific conductance. Total dissolved solids or specific conductance shall not be changed to the extent that the indigenous aquatic community is adversely affected.

      (g) Total suspended solids. Total suspended solids shall not be changed to the extent that the indigenous aquatic community is adversely affected.

      (h) Settleable solids. The addition of settleable solids that may alter the stream bottom so as to adversely affect productive aquatic communities is prohibited.

      (i) Ammonia. The concentration of the un-ionized form shall not be greater than 0.05 mg/l at any time instream after mixing. Un-ionized ammonia shall be determined from values for total ammonia-N, in mg/l, pH and temperature, by means of the following equation:

      Y = 1.2 (Total ammonia-N)/(1 + 10^pKa-pH)

      pk_a = 0.0902 + (2730/(273.2 + T_c))

Where:

      T_c = temperature, degrees Celsius.

      Y = un-ionized ammonia (mg/l).

      (j) Toxics.

      1. The allowable instream concentration of toxic substances, or whole effluents containing toxic substances, which are noncumulative or nonpersistent with a half-life of less than ninety-six (96) hours, shall not exceed:

      a. One-tenth (0.1) of the ninety-six (96) hour median lethal concentration (LC₅₀) of representative indigenous or indicator aquatic organisms; or

      b. A chronic toxicity unit of 1.00 utilizing the twenty-five (25) percent inhibition concentration, or LC₂₅.

      2. The allowable instream concentration of toxic substances, or whole effluents containing toxic substances, which are bioaccumulative or persistent, including pesticides, if not specified elsewhere in this section, shall not exceed:

      a. 0.01 of the ninety-six (96) hour median lethal concentration (LC₅₀) of representative indigenous or indicator aquatic organisms; or

      b. A chronic toxicity unit of 1.00 utilizing the IC₂₅.

      3. In the absence of acute criteria for pollutants listed in Table 1 of Section 6 of this administrative regulation or for other substances known to be toxic but not listed in this administrative regulation, or for whole effluents which are acutely toxic, the allowable instream concentration shall not exceed the LC₁ or one-third (1/3) LC₅₀ concentration derived from toxicity tests on representative indigenous or indicator aquatic organisms or exceed three-tenths (0.3) acute toxicity units.

      4. If specific application factors have been determined for a toxic substance or whole effluent such as an acute to chronic ratio or water effect ratio, they may be used instead of the one-tenth (0.1) and 0.01 factors listed in this subsection upon approval by the cabinet.

      5. Allowable instream concentrations for specific pollutants for the protection of warm water aquatic habitat are listed in Table 1 of Section 6 of this administrative regulation. These concentrations are based on protecting aquatic life from acute and chronic toxicity and shall not be exceeded.

      (k) Total residual chlorine. Instream concentrations for total residual chlorine shall not exceed an acute criteria value of nineteen (19) mg/l or a chronic criteria value of eleven (11) mg/l.

      (2) Cold water aquatic habitat. The following parameters and criteria are for the protection of productive cold water aquatic communities and streams that support trout populations, whether self-sustaining or reproducing, on a year-round basis. The criteria adopted for the protection of warm water aquatic life also apply to the protection of cold water habitats with the following additions:

      (a) Dissolved oxygen.

      1. A minimum concentration of six and zero-tenths (6.0) mg/l as a daily average and five and zero-tenths (5.0) mg/l as an instantaneous minimum shall be maintained.

      2. In lakes and reservoirs that support trout, the concentration of dissolved oxygen in waters below the epilimnion shall be kept consistent with natural water quality.

      (b) Temperature. Water temperature shall not be increased through human activities above the natural seasonal temperatures.

      Section 5. Domestic Water Supply Use. Maximum allowable in-stream concentrations for specific substances, to be applicable at the point of withdrawal for use for domestic water supply from surface water sources are specified in Table 1 of Section 6 of this administrative regulation and shall not be exceeded.

      Section 6. Pollutants. Allowable instream concentrations of pollutants are listed in Table 1 of this section.

Table 1
Pollutant	CAS^1 Number	Water Quality Criteria mg/L^2
		Human Health:		Warm Water Aquatic Habitat^3:
		DWS^4	Fish^5	Acute	Chronic
Acenaphthene	83329	670	990
Acrolein	107028	190	290
Acrylonitrile	107131	0.051	0.25
Aldrin	309002	0.000049	0.000050	3.0
alpha-BHC	319846	0.0026	0.0049
alpha-Endosulfan	959988	62	89	0.22	0.056
Anthracene	120127	8,300	40,000
Antimony	7440360	5.6	640
Arsenic	7440382	10.0		340	150
Asbestos	1332214	7 million fibers/L
Barium	7440393	1,000
Benzene	71432	2.2	51
Benzidine	92875	0.000086	0.00020
Benzo(a)anthracene	56553	0.0038	0.018
Benzo(a)pyrene	50328	0.0038	0.018
Benzo(b)fluoranthene	205992	0.0038	0.018
Benzo(k)fluoranthene	207089	0.0038	0.018
Beryllium	7440417	4
Beta-BHC	319857	0.0091	0.017
Beta-Endosulfan	33213659	62	89	0.22	0.056
bis(chloromethyl)ether	542881	0.00010	0.00029
bis(2-chloroethyl)ether	111444	0.030	0.53
bis(2-chloroisopropyl)ether	108601	1,400	65,000
bis(2-ethylhexyl)phthalate	117817	1.2	2.2
Bromoform	75252	4.3	140
Butylbenzyl phthalate	85687	1,500	1,900
Cadmium	7440439	5		e(1.0166 (ln Hard*)-3.924)	e(0.7409 (ln Hard*)- 4.719)
Carbon tetrachloride	56235	0.23	1.6
Chlordane	57749	0.00080	0.00081	2.4	0.0043
Chloride	16887006	250,000		1,200,000	600,000
Chlorobenzene	108907	680	21,000
Chlorodibromomethane	124481	0.40	13
Chloroform	67663	5.7	470
Chloropyrifos	2921882			0.083	0.041
Chromium	N/A	100