View all text of Subpart B [§ 439.20 - § 439.27]
§ 439.22 - Effluent limitations attainable by the application of the best practicable control technology currently available (BPT).
Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BPT:
(a) The limitation for BOD
(1) The long-term average daily BOD
(2) To assure equity in the determination of NPDES permit limitations regulating discharges subject to this subpart, calculation of the long-term average daily BOD
(3) The practices of recovery, and/or separate disposal or reuse include: physical separation and removal of separable mycelia; recovery of solvents from wastestreams; incineration of concentrated solvent wastestreams (including tar still bottoms); and broth concentration for disposal other than to the treatment system. This part does not prohibit the inclusion of such wastes in raw waste loads in fact, nor does it mandate any specific practice, but rather describes the rationale for determining NPDES permit limitations. The effluent limitation for BOD
(b) The limitation for TSS is the same as specified in § 439.12(b).
(c) Except for the provisions in paragraph (d) of this section, the limitations for COD are as follows:
Effluent Limitations (BPT)
Regulated parameter | Maximum daily 1 | Maximum monthly average 1 | COD | 228 | 86 |
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1 mg/L (ppm)
(d) If the maximum monthly average COD concentration in paragraph (c) of this section is higher than a concentration value reflecting a reduction in the long-term average daily COD load in the raw (untreated) process wastewater of 74 percent multiplied by a variability factor of 2.2, then a monthly average limitation for COD corresponding to the lower concentration value must be applied.