Oklahoma Administrative Code
Title 35 - Oklahoma Department of Agriculture, Food, and Forestry
Chapter 45 - Water Quality Standards Implementation Plan
Subchapter 1 - Water Quality Standards Implementation Plan
Section 35:45-1-4 - Pertinent water quality standards

Universal Citation: OK Admin Code 35:45-1-4

Current through Vol. 41, No. 13, March 15, 2024

(a) Pursuant to Section 303 of the CWA, Oklahoma's surface water quality standards are promulgated by the OWRB at OAC 785:45, Subchapter 5. Surface water quality standards are comprised of three elements:

(1) Beneficial uses, designated to apply to specific water bodies or defined water body segments, as listed in Appendix A to OAC 785:45, generally address the goals of the CWA. Certain default beneficial uses are assumed for waters not listed in Appendix A until a UAA indicates otherwise. The subset of beneficial uses which address water quality are:
(A) Public and Private Water Supply (PPWS) (OAC 785:45-5-10 );

(B) Fish and Wildlife Propagation (F&W) (OAC 785:45-5-12 ), according to one of four fishery subcategories:
(i) Habitat-Limited Aquatic Community (HLAC).

(ii) Warm Water Aquatic Community (WWAC).

(iii) Cool Water Aquatic Community (CWAC).

(iv) Trout Fishery (Put and Take) - Criteria used in the protection of F&W shall include DO, T0, pH, Oil and Grease, Bio Criteria, toxic substances, turbidity, and sediments.

(C) Agriculture (Ag) (OAC 785:45-5-13 );

(D) Primary Body Contact Recreation (PBCR) (OAC 785:45-5-16 );

(E) Secondary Body Contact Recreation (OAC 785:45-5-17 ); and

(F) Aesthetics (OAC 785:45-5-19 ).

(G) Fish Consumption (OAC 785:45-5-20 ).

(2) Numerical and narrative criteria (OAC 785:45-5) apply statewide. Numerical criteria are pollutant-specific and apply to a water body according to its beneficial uses in accordance with OAC 785:45. Narrative criteria are generally referred to as "free from" prohibitions.

(3) Numerical salinity water quality standards are only for agricultural beneficial uses (irrigation and watering livestock). Stream segment averages of historic data for chlorides, sulfates, and TDS are available in Appendix F for most stream segments statewide. The WQS also allows for use of upstream/background data and data from surrounding streams instead of these averages if this data provides a more appropriate basis for setting standards for a specific stream (OAC 785:45-5-13(e) and (f) ). However, for the protection of Agriculture use, neither long nor short term average concentrations of minerals shall be required to be less than 700 mg/l for TDS, nor less than 250 mg/l for either chlorides or sulfates (OAC 785-45-5-13 (g)).

(4) General Narrative Criteria for Minerals at OAC OAC 785:45-5-9(a) states that "Increased mineralization from other elements such as, but not limited to, calcium, magnesium, sodium, and their associated anions shall not impair any beneficial use," which OWRB interprets as meaning that neither salinity nor other minerals shall be allowed to impair the PPWS, F&W, PBCR, and other beneficial uses listed for streams in the WQS.

(5) Excess sediment impacts may be addressed through the numeric turbidity standards established for F&W. Heavy metal numerical WQS have been set by OWRB for many beneficial uses.

(6) A water quality antidegradation policy, which applies statewide and is, consistent with the goals of the CWA, is found at OAC 785:45, Subchapter 3. Antidegradation policy implementation is found at OAC 785:45-5-25 and OAC 785:46, Subchapter 13. Levels of protection are as follows:
(A) Attainment or maintenance of existing or designated beneficial uses.

(B) Maintenance quality of improved waters.

(C) Maintenance of beneficial uses and water quality in higher quality waters and sensitive public and private water supplies of the state, as well as in waters of ecological or recreational significance.

(D) Prohibition of any water quality degradation from new point source discharges or increased loading from existing discharges into waters designated as outstanding resource waters and scenic rivers.

(7) Special provision at OAC 785:45-5-29 - Delineation of Nutrient Limited Watershed (NLW) areas specifies spatial limitations of these areas that require additional protection.

(b) Although not required by any provision of the CWA, the OWRB has promulgated groundwater quality standards for the state at OAC 785:45, Subchapter 7. Groundwater quality standards and protection are comprised of seven elements:

(1) Beneficial uses, designated to apply to the groundwater situated below the surface of the dedicated land identified in a groundwater use permit or right issued by the OWRB. Such beneficial uses are defined at OAC 785:45-7-3(b) and may include, but are not limited to:
(A) Public and Private Water Supply (including municipal use and domestic use).

(B) Agriculture for irrigation or livestock watering.

(C) Industrial and municipal process and cooling water.

(2) Classifications, found at OAC 785:45-7-3(a) are as follows:
(A) Class I (Special Source Groundwater): Groundwaters where exceptional water quality exists, where there is an irreplaceable source of water, where it is necessary to maintain an outstanding groundwater resource or where the groundwater is ecologically important. This class of groundwater is considered to be very vulnerable to contamination and includes:
(i) All groundwater located beneath the watersheds of surface waters designated as Scenic Rivers in Appendix A to OAC 785:45.

(ii) Groundwater located underneath lands located within the boundaries of areas with waters of ecological and/or recreational significance listed in Tables 1 and 2 of Appendix B to OAC 785:45.

(iii) Groundwater located underneath lands within the boundaries of a state-approved wellhead or source water protection area for public water supply.

(B) Class II (General Use Groundwater): Groundwaters capable of being used as a drinking water supply with conventional or no treatment methods, with the potential for multiple beneficial uses, and with mean TDS levels < 3000 mg/l.

(C) Class III (Limited Use Groundwater): Poor quality groundwaters due to natural conditions, which require extensive treatment for use as a drinking water source, with mean TDS levels of = 3000 mg/l and < 5000 mg/l.

(D) Class IV (Highly Mineralized Treatable Groundwater): Very poor quality groundwaters due to natural conditions, which require extensive treatment for use as a drinking water source, having mean TDS levels = 5000 mg/l but <10000 mg/l.

(3) Beneficial use designations: Class I and II, not identified in Appendix H of OAC 785:45, shall be public and private water supply, agriculture, and Industrial and municipal process ad cooling water. Class III and IV, not identified in Appendix H of OAC 785:45, shall be agriculture, and Industrial and municipal process and cooling water. Appendix H specifies beneficial uses for groundwater contained in the appendix.

(4) Vulnerability level: Certain hydrogeologic basins are classified according to its vulnerability to contamination and identified as Very Low, Low, Moderate, High and Very High per Table 1 of Appendix D of OAC 785:45.

(5) Nutrient-vulnerable groundwater: Certain groundwaters are subject to further designation as nutrient-vulnerable groundwater per Table 2 of Appendix D.

(6) Criteria for protection of groundwater quality:
(A) Groundwaters of the state shall be maintained to prevent alteration of their chemical properties by harmful substances not naturally found in groundwater.

(B) Protective measures shall be at all times maintained which are adequate to preserve and protect existing and designated groundwater basin classifications and which are sufficient to minimize the impact of pollutants on groundwater quality.

(C) The concentration of any synthetic substances or any substances not naturally occurring in that location shall not exceed the PQL in an unpolluted groundwater sample using laboratory technology.

(D) Prescriptive measures shall be developed by each state environmental agency and included in their WQSIP, and they shall be implemented to prevent-groundwater pollution caused by any person or entity within their jurisdictional area of environmental responsibility.

(E) Each state environmental agency shall consider the hydrogeologic basin's vulnerability level and designated nutrient vulnerable groundwaters for surface activities with the potential to contaminate groundwater.

(7) Criteria for corrective action:
(A) Groundwater that has been polluted as a result of human activities shall be restored to a quality that will support uses designated in OAC 785:45-7-3(b) for that groundwater or meet the requirements of a site specific remediation plan approved by the appropriate state environmental agency.

(B) Measures to remedy, control or abate groundwater pollution caused by any person shall be the responsibility of each state environmental agency within its jurisdictional areas of environmental responsibility as prescribed in the agency's WQSIP.

Added at 18 Ok Reg 3409, eff 6-28-01 (emergency); Added at 19 Ok Reg 951, eff 5-13-02; Amended at 22 Ok Reg 2332, eff 7-11-05; Amended at 25 Ok Reg 1820, eff 7-1-08

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