(A) All prohibited discharges listed in § 50.32 and as amended shall apply to this subchapter.
(B) (1) No industrial user shall discharge wastewater containing concentrations of the following enumerated materials exceeding the following values:
Constituent Concentration (mg/L)
Arsenic 0.2
Cadmium 0.2
Chromium - total 2.0
Chromium - hexavalent 2.0
Copper 0.7
Iron 15.0
Mercury 0.004
Molybdenum 0.1
Nickel 2.0
Silver 2.0
Zinc 4.0
Cyanide 1.0
Phenols 25.0
(2) The town may impose mass limitations on dischargers if it is believed that dilution is being used to meet the pretreatment standards or requirements of this chapter. These standards do not override other, more stringent standards established by federal or state agencies or departments. The town will enforce applicable federal, state, and local standards and regulations. A discharger of industrial wastewater shall meet the most stringent applicable standard in all cases.
(C) Dilution.
(1) Dilution of the effluent from a treatment works or from any wastewater source is not acceptable as a method of treatment of wastes in order to meet the standards set forth herein. Rather, it shall be the obligation of any person discharging contaminants of any kind to the waters of the state to provide the best degree of treatment of wastewater consistent with technological feasibility and economic reasonableness. To determine what kind of treatment is the "best degree of treatment" within the meaning of this division, a person shall consider the following:
(a) What degree of waste reduction can be achieved by process change, improved housekeeping, and recovery of individual waste components for reuse; or
(b) Whether individual process wastewater streams should be segregated or combined.
(2) Measurement of contaminant concentrations to determine compliance with the effluent standards set forth herein shall be made at the point of discharge to the town's sewage works.
(D) Background concentrations. Because the effluent standards set forth herein are based upon concentrations achievable with conventional treatment technology that is largely unaffected by ordinary levels of contaminants in intake water, they are absolute standards that must be met without subtracting background concentrations. However, it is not the intent of these regulations to require users to clean up contaminations caused essentially by upstream sources or to require treatment when only traces of contaminants are added to the background. Compliance with the numerical effluent standards is therefore not required when effluent concentrations in excess of the standards result entirely from influent contamination, evaporation, and/or the incidental addition of traces of materials not utilized or produced in the activity that is the source of the waste.
(E) Sampling. Any person subject to reporting requirements of this chapter shall submit the results of the sampling and analysis in accordance with 40 CFR 403.12 (b)(5). Except as otherwise specifically provided, compliance with the numerical standards set forth herein shall be determined on the basis of 24-hour composite samples. If sampling performed by an industrial user indicates a violation, the user shall notify the Superintendent and IDEM within 24 hours of becoming aware of the violation. The user shall also repeat the sampling and analysis and submit the results of the repeat analysis to the Superintendent and IDEM within 30 days after becoming aware of the violation. The user is not required to resample if the Superintendent and IDEM monitors at the user's facility at least once per month, or if the Superintendent and IDEM samples between the user's initial sampling and when the user receives the results of this sampling.
(Ord. 2007-7, passed 6-11-07)