The federal Clean Water Act (CWA) sets a national goal to restore and maintain the chemical, physical, and biological integrity of the nation's waters and to eliminate pollutant discharges into navigable waters. ?The CWA sets effluent limitations for discharges of pollutants to navigable waters. ?The Department of Ecology (Ecology) has received delegated authority from the United States Environmental Protection Agency (EPA) to carry out the CWA in Washington. ?As part of this responsibility, Ecology issues required National Pollutant Discharge Elimination System (NPDES) wastewater discharge permits, except for federally owned facilities and for permits on tribal lands, as well as state waster discharge permits under state law. ?The NPDES permits regulate discharges to surface water from commercial industry or publicly owned treatment works, also referred to as municipal wastewater treatment facilities, and state waste discharge permits also regulate discharges to groundwater.? Wastewater discharge permits generally place limits on the quantity and concentrations of contaminants that may be discharged, and permits may require wastewater treatment or impose operating or other conditions, including monitoring, reporting, and spill prevention planning. ?The current Water Treatment Plant General Permit issued by Ecology requires a permit holder to notify Ecology immediately, and not later than 24 hours, upon becoming aware of a spill or discharge that could constitute a threat to human health, welfare, or the environment, and to take appropriate action to correct or minimize health or environmental threats from the spill.
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Combined sewer overflow systems discharge untreated or partially treated sewage mixed with stormwater to waterways. ?They receive overflow from treatment plants or combined sewers when the capacity of those treatment plants or combined sewers is exceeded during heavy rain events.
Ecology must develop certain new tools to publicly communicate intentional or accidental sewage spills, including from combined sewers, that do not meet water discharge permit requirements. ?These new public communication requirements include: