Okla. Admin. Code § 252:628-3-6

Current through Vol. 42, No. 6, December 2, 2024

Section 252:628-3-6 - IPR benchmarks for additional conservative parameters

(a)Additional conservative parameters. Refer to Appendix A of this Chapter for the list of additional conservative parameters.

(b)Effluent limitations for TDS. Effluent limitations for TDS shall be set so the maximum ambient concentration will not exceed the greater of 700 milligrams per liter or two (2) standard deviations above the mean background TDS value of the receiving waterbody prior to IPR Source Water discharge. The calculated permit limit shall be applied as a monthly average permit limit in the OPDES discharge permit. The daily maximum permit limit shall be established as 1.5 times the monthly average permit limits. Background levels may be established from any combination of scientifically defensible data, including historical data, segment averages, and baseline monitoring.

(c)Permit reopener for TDS. Should receiving water monitoring for TDS indicate that the receiving waterbody has exceeded the greater of 700 milligrams per liter or two (2) standard deviations above the mean background TDS value prior to IPR discharge, the permit may be reopened and modified to reduce effluent limitations or increase frequency of effluent monitoring.

(d)Effluent limitations for additional conservative parameters other than TDS. Effluent limitations for additional conservative parameters other than TDS shall be calculated to meet action levels established in accordance with Subchapter 11 of this Chapter. The calculated permit limits shall be applied as monthly average permit limits in the OPDES discharge permit. Daily maximum permit limits shall be established as 1.5 times the monthly average permit limits.

(e)Mixing zones. Complete mixing of effluent and receiving water shall be used to determine appropriate effluent limitations for additional conservative parameters, unless superseded by mixing zones or dilution factors established in OAC 252:740. An HMB model or other DEQ-approved model shall be used for implementation purposes.

(f)Effluent monitoring requirements. The following effluent monitoring requirements apply:

(1) IPR Source Water discharges shall be monitored for additional conservative parameters monthly.

(2) DEQ may increase the monitoring frequencies listed in (f)(1) of this Section for a period not to exceed two years during the initial permit cycle for the purpose of establishing the pattern and extent of variation for a given parameter.

Okla. Admin. Code § 252:628-3-6

Adopted by Oklahoma Register, Volume 35, Issue 24, September 4, 2018, eff. 9/15/2018

Amended by Oklahoma Register, Volume 40, Issue 6, December 1, 2022, eff. 10/25/2022

Amended by Oklahoma Register, Volume 40, Issue 24, September 1, 2023, eff. 9/15/2023