S.C. Code Regs. § § 61-9.133.100

Current through Register Vol. 48, 12, December 27, 2024

Section 61-9.133.100 - Purpose

All terms not defined herein shall have the meaning given them R.61-9.122 or R.61-9.124. Terms used in this regulation are defined as follows:

(a) "7-day average." The arithmetic mean of pollutant parameter values for samples collected in a period of 7 consecutive days.

(b) "30-day average." The arithmetic mean of pollutant parameter values of samples collected in a period of 30 consecutive days.

(c) "BOD₅" The five day measure of the pollutant parameter biochemical oxygen demand (BOD).

(d) "CBOD₅". The five day measure of the pollutant parameter carbonaceous biochemical oxygen demand (CBOD₅).

(e) "Effluent concentrations consistently achievable through proper operation and maintenance."

(1) For a given pollutant parameter, the 95th percentile value for the 30-day average effluent quality achieved by a treatment works in a period of at least two years, excluding values attributable to upsets, bypasses, operational errors, or other unusual conditions, and

(2) A 7-day average value equal to 1.5 times the value derived under paragraph (f)(1) of this section.

(f) "Facilities eligible for treatment equivalent to secondary treatment." Treatment works shall be eligible for consideration for effluent limitations described for treatment equivalent to secondary treatment (section133.105), if:

(1) The BOD₅ and TSS effluent concentrations consistently achievable through proper operation and maintenance (section133.101(f)(f) of the treatment works exceed the minimum level of the effluent quality set forth in section133.102(a)(a) and section133.102(b)(b).

(2) A trickling filter or waste stabilization pond is used as the principal process, and

(3) The treatment works provide significant biological treatment of municipal and/or domestic wastewater.

(g) "mg/l." Milligrams per liter.

(h) "Percent removal." A percentage expression of the removal efficiency across a treatment plant for a given pollutant parameter, as determined from the 30-day average values of the raw wastewater influent pollutant concentrations to the facility and the 30-day average values of the effluent pollutant concentrations for a given time period.

(i) "Significant biological treatment." The use of an aerobic or anaerobic biological treatment process in a treatment works to consistently achieve a 30-day average of at least 65 percent removal of BOD₅.

(j) "Significantly more stringent limitation" means BOD₅ and TSS limitations necessary to meet the percent removal requirements of at least 5 mg/l more stringent than the otherwise applicable concentration-based limitations (e.g., less than 25 mg/l in the case of the secondary treatment limits for BOD₅ and TSS), or the percent removal limitations in section133.102 and section133.105, if such limits would, by themselves, force significant construction or other significant capital expenditure.

(k) "TSS." The pollutant parameter total suspended solids.

S.C. Code Regs. § 61-9.133.100