The National Pollution Discharge Elimination System has set limit on BOD (Biochemical Oxygen Demand) and the level of suspended solids that may be discharged into the nation’s lakes and streams. The state of Ohio issues a NPDES Permit, which specifies BOD and suspended solid discharge limits for municipal wastewater treatment facilities. The Water Pollution Control Center’s permit specifies a BOD of 15 mg/l and a suspended solid limit of 20.0 parts per million (ppm). The Center’s average cBOD discharge of 3.6 mg/l and suspended solid discharge of 8.3 ppm for 2010 are well below the NPDES specified limits.
How big is a ppm? One part per million is equal to one minute in two years or one penny in $10,000. The mission of the WPCC is to ensure that the plant’s discharge will meet or exceed federal and state guidelines for protecting Lake Erie, our receiving waters. The conversion to UV disinfection and substantial reduction of suspended solids in our wastewater treatment process is supportive of the movement to protect the lake’s ecosystem and preserve its plant and animal life – good news for the area’s environmentalists and sportsmen!