40 CFR 421.3 - Monitoring and reporting requirements.
The following special monitoring requirements apply to all facilities controlled by this regulation:
(a) The monthly average regulatory values shall be the basis for the monthly average discharge in direct discharge permits and for pretreatment standards. Compliance with the monthly discharge limit is required regardless of the number of samples analyzed and averaged.
(b) Periodic analysis for cyanide are not required for a facility in the primary beryllium subcategory (subpart O of this part) when both of the following conditions are met:
(1) The first wastewater sample taken in each calandar year has been analyzed and found to contain less than 0.07 mg/1 cyanide.
(2) The owner or operator of the primary beryllium manufacturing facility certifies in writing to the POTW authority or permit issuing authority that cyanide is neither generated nor used in the beryllium manufacturing process employed at that facility.