Current through Register Vol. 54, No. 45, November 9, 2024
Section 92a.27 - Sewage discharges(a) The following additional application requirements apply to new and existing sewage dischargers (including POTWs and privately owned treatment works), as applicable:(1) The following sewage dischargers shall provide the results of whole effluent toxicity testing to the Department:(i) Sewage dischargers with design influent flows equal to or greater than 1.0 million gallons per day.(ii) Sewage dischargers with approved pretreatment programs or who are required to develop a pretreatment program.(2) In addition to the sewage dischargers in paragraph (1), the Department may require other sewage dischargers to submit the results of toxicity tests with their permit applications, based on consideration of the following factors: (i) The variability of the pollutants or pollutant parameters in the sewage effluent (based on chemical-specific information, the type of treatment facility and types of industrial contributors).(ii) The dilution of the effluent in the receiving water (ratio of effluent flow to receiving stream flow).(iii) Existing controls on point or nonpoint sources, including calculations of TMDLs for the waterbody segment, and the relative contribution of the sewage discharger.(iv) Receiving surface water characteristics, including possible or known water quality impairment, and whether the sewage discharges to an estuary, one of the Great Lakes or a surface water that is classified as a High Quality Water or an Exceptional Value Water under Chapter 93 (relating to water quality standards).(v) Other considerations including, but not limited to, the history of toxic impact and compliance problems at the sewage discharge facility, which the Department determines could cause or contribute to adverse water quality impacts.(3) For sewage dischargers required under paragraph (1) or (2) to conduct toxicity testing, the EPA's methods or other protocols approved by the Department, which are scientifically defensible and sufficiently sensitive to detect aquatic toxicity and approved by the Department, shall be used. The testing shall have been performed since the last NPDES permit reissuance, or when requested by the Department, whichever occurred later.(b) CSO dischargers shall submit the following information: (1) The results of an evaluation determining the frequency, extent and cause of the CSO discharge, including identifying the points of inflow into combined systems.(2) An evaluation of the water quality impacts of the CSO discharge on receiving waters.(3) A description of the nine minimum controls (NMCs) described in the EPA publication entitled "Combined Sewer Overflows-Guidance for Nine Minimum Controls" (EPA publication number 832-B-95-003 (September 1995) as amended or updated) used at the facility to minimize or eliminate the CSO discharge impact on receiving water quality.(4) A long-term control plan (LTCP) to minimize or eliminate the CSO discharge with an implementation schedule.(5) An update on the progress made with the implementation of the LTCP and future activities with schedules to comply with water quality standards.