The City of Mason, like most other communities in Michigan, operates under a National Pollutant Discharge Elimination System permit (NPDES) administered by the
Michigan Department of Environment, Great Lakes, and Energy (EGLE). This permit is a legal document that requires the wastewater treatment plant to produce a final effluent that will maintain compliance with the regulations and the limitations stated within the (NPEDS) permit. Our treated wastewater effluent is discharged into Sycamore Creek.
The wastewater collections system consists of 32 miles of sewer lines and four lift stations. The collections system conveys sewage from homes and businesses to the wastewater treatment plant. The City's plant is a class B plant designed to treat a maximum of 1.5 million gallons of wastewater per day (MGD) using the activated sludge treatment process with anaerobic digestion. The WWTP is staffed 7 days a week 365 days a year.
Sewage typically flows by gravity through the lines. There are times when significant changes in elevation occur, particularly during new development, when the sewage must be lifted from a lower elevation to a higher elevation. This is accomplished by 4 lift stations located in the collections system.
The wastewater treatment plant was constructed in 1958 with additional improvements added in 1975, 1977, 2011, and in 2016. In 2016 the City installed a wastewater headworks facility sized for 1.5 MGD with a peak pumping capacity of 6 MGD.
