Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT)

Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in ss. NR 270.0015 , 270.002 and 270.003 and 40 CFR 125.30-125 .32, any existing point source subject to this subcategory shall achieve the following limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT): (1) The concentration of pollutants discharged in mine drainage from mines, either open pit or underground, that produce mercury ores may not exceed: (2) (a) Except as provided in this subsection, there may not be discharge of process wastewater to navigable waters from mills beneficiating mercury ores by gravity separation methods or by froth-flotation methods. (b) In the event that the annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility exceeds the annual evaporation, a volume of water equal to the difference between annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility and annual evaporation may be discharged subject to the limitations set forth in sub. (1) .