U.S. Code of Federal Regulations
Regulations most recently checked for updates: Jun 06, 2023
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 maximum monthly average 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 waste streams; incineration of concentrated solvent wastestreams (including tar still bottoms); and concentration of broth 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 maximum monthly average limitation for TSS, expressed as mass loading (lbs., kg) per day, must be calculated as 1.7 times the BOD
(c) Except as provided 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 | 1675 | 856 |
1mg/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 the monthly average limitation for COD corresponding to the lower concentration value must be applied.
(e) The effluent limitations for cyanide are as follows:
Effluent Limitations (BPT)
Regulated parameter | Maximum daily 1 | Maximum monthly average 1 |
---|---|---|
Cyanide (T) | 33.5 | 9.4 |
1mg/L (ppm).
(f) When monitoring for cyanide at the end-of-pipe is impractical because of dilution by other process wastewaters, compliance with the cyanide effluent limitations in paragraph (e) of this section must be demonstrated at in-plant monitoring points pursuant to 40 CFR 122.44(i) and 122.45(h). Under the same provisions, the permitting authority may impose monitoring requirements on internal wastestreams for any other parameter(s) regulated by this section.
(g) Compliance with the limitation in paragraph (e) or (f) of this section may be achieved by certifying to the permit issuing authority that the facility's manufacturing processes neither use nor generate cyanide.