Okla. Admin. Code § 460:12-1-4

Current through Vol. 42, No. 8, January 2, 2025

Section 460:12-1-4 - Oklahoma's Water Quality Standards

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

(1) Beneficial uses are designated to apply to specific water bodies or defined water body segments, as listed in Appendix A to OAC 785:45, and which generally address the goals of the CWA. Certain default beneficial uses are assumed for waters not listed in Appendix A until a UAA may indicate otherwise. The subset of beneficial uses which address water quality (as opposed to quantity) 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)

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

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

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

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

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

(2) Numerical and narrative criteria found in 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 Appendix G.

(A) Excess sediment impacts may be addressed through the numeric turbidity standards established for F&W.

(B) Heavy metal numerical WQ standards have been set by OWRB for many beneficial uses.

(3) A water quality antidegradation policy applies statewide and is consistent with the goals of the CWA, as found at OAC 785:45-3. Antidegradation policy implementation is found at OAC 785-45-5-25 and OAC 785-46-13. There are three levels of protection:

(A) Attainment or maintenance of existing or designated beneficial uses (Tier 1).

(B) Maintenance of beneficial uses and water quality in higher quality waters and sensitive water supplies of the state, as well as in waters of ecological and/or recreational significance (Tier 2).

(C) Prohibition of any water quality degradation from new point source discharges or increased loading from existing discharges into waters designated as outstanding resource waters (Tier 3).

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

(1) Beneficial uses, designated by the classification listed below in 2b. 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 and domestic use)

(B) Agriculture (including irrigation and non-irrigation use)

(C) Industrial and Municipal Process and Cooling Water

(2) Classifications, found at OAC 785:45-7-2(d) and 45-7-3(a) are as follows:

(A) "Special Source Groundwater" is groundwater:

(i) Where exceptional water quality exists;

(ii) Where there is an irreplaceable source of water;

(iii) Where it is necessary to maintain an outstanding groundwater resource; or

(iv) 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 located within the boundaries of a state-approved wellhead protection area for public water supply.

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

(C) Class III (Limited Use Groundwater) consists of poor quality groundwaters caused by naturally occurring contaminants, which require extensive treatment for use as a drinking water source, having mean TDS levels 2: 3000 mg/L but < 5000mg/L.

(D) Class N (Highly Mineralized Treatable Groundwater) which is very poor quality groundwater due to natural conditions, which require extensive treatment for use as a drinking water source, having a mean TDS 5000 mg/L but < 10,000 mg/L.

(3) Protective measures and corrective actions, composed of:

(A) Numerical criteria for any synthetic substance or substance not naturally occurring greater than concentrations found in background conditions, as well as practically measurable levels of toxics listed pursuant to Section 307(a) of the CWA, which, if exceeded, constitute groundwater pollution and may require corrective action.

(B) Narrative criteria requiring that protective measures 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.

(C) Development of prescriptive measures by each state environmental agency in their WQSIP, and subsequent use of such measures, to prevent, control or abate groundwater pollution caused by any person or entity within their jurisdictional area of environmental responsibility.

(D) Consideration by each state environmental agency of a hydrogeologic basin's vulnerability level, as developed in OWRB Technical Report 99-1, Statewide Groundwater Vulnerability map of Oklahoma, Noel I. Osburn and Ray H. Hardy, for surface activities with the potential to contaminate groundwater.

Okla. Admin. Code § 460:12-1-4

Adopted by Oklahoma Register, Volume 38, Issue 24, September 1, 2021, eff. 9/11/2021