Lyon Township Wastewater Treatment Plant (Lyon Township, Oakland County)

Sydney Ruhala, RuhalaS@Michigan.gov or 517-599-5356.

The Lyon Township Wastewater Treatment Plant (WWTP), located at 53656 Ten Mile Road, discharges treated wastewater to the groundwater under a state Groundwater Discharge Permit issued to Lyon Charter Township (township). The treatment system consists of sequencing batch reactors and a chemical feed system. The final treated effluent is discharged to the groundwater on-site via rapid infiltration basins (i.e., sand beds) located in two discharge areas (i.e., the eastern and western rapid infiltration basins). The WWTP also has an approved Industrial Pretreatment Program (IPP), which requires industrial dischargers that send their wastewater to the WWTP, to use treatment techniques and management practices to reduce or eliminate the discharge of harmful pollutants to the sanitary sewers. The IPP is designed to protect the municipal WWTP and the environment.

As part of a statewide sampling effort, EGLE sampled the WWTP's influent, effluent, final treated solids, and four groundwater monitoring wells for PFAS in Fall 2021.

Estimated groundwater flow direction across the eastern rapid infiltration basins and WWTP is to the northwest, west, or southwest depending on location, while estimated groundwater flow direction across the western rapid infiltration basins is to the southwest.

Content posted August 2022.

EGLE will continue to work with the Michigan Department of Health and Human Services (MDHHS), the Oakland County Health Department, and the township to evaluate residential wells in the area and expand residential drinking water well testing if determined to be necessary.

EGLE will continue to work with the township to determine the extent of PFAS contamination in groundwater at the WWTP. EGLE will continue to work with the township to determine potential sources of PFAS to the WWTP and implement source reduction controls under their IPP.