§ 133.101 Definitions.
Terms used in this part 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) Act. The Clean Water Act (33 U.S.C. 1251 et seq., as amended).
(d) BOD. The five day measure of the pollutant parameter biochemical oxygen demand (BOD).
(e) CBOD5. The five day measure of the pollutant parameter carbonaceous biochemical oxygen demand (CBOD5).
(f) 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.