The web Browser you are currently using is unsupported, and some features of this site may not work as intended. Please update to a modern browser such as Chrome, Firefox or Edge to experience all features Michigan.gov has to offer.
Lyon Township Wastewater Treatment Plant (Lyon Township, Oakland County)
Web content may not routinely be updated on this page. Please contact the Site Lead for the most up-to-date status of the site.
Content posted August 2022.
EGLE Site Lead
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.
- On May 5, 2022, the township resampled the four groundwater monitoring wells sampled in November 2021. All four monitoring wells exceeded criteria for PFOA. The highest result was 34 ppt PFOA. The township also collected a surface water sample from the Blackwood Drain, upstream of the WWTP. PFAS was not detected in the surface water sample.
- On May 19, 2022, the township collected a sample of water from one residential well. PFAS was not detected in the well.
- On May 31, 2022, the township sampled two additional groundwater monitoring wells. Both monitoring wells exceeded criteria for PFOA. The highest result was 23 ppt PFOA.
- On June 14-16, 2022, the township collected samples of water from four residential wells and one test well. PFAS was not detected in the five wells.
- 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.
Residential Well Testing/Alternate Water Information
- 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.
Upcoming Community Engagement
- None scheduled at this time.
Sampling Results Summary
Type of Sample
Date Sampled (or Range)
Number of Sample Results Received
Number of Samples above Criteria*
Groundwater Monitoring Wells
|November 2021 - May 2022||6||6|
|Residential Wells||May 2022 - June 2022||6||0|
|Surface Water||May 2022||1||0|
*Surface water samples are compared to Rule 57 non-drinking water values of 12 ppt for PFOS, 170 ppt for PFOA, and 670,000 ppt for PFBS.
- None at this time.
2021 - 2022
- On November 3, 2021, EGLE contractors sampled the influent, effluent, final treated solids, and four downgradient groundwater monitoring wells for PFAS at the WWTP as part of a statewide sampling effort.
- On January 19, 2022, EGLE received the sampling results. All four monitoring wells exceeded groundwater cleanup criteria for PFOA. The highest result was 40.1 ppt PFOA. Two of the monitoring wells were located downgradient from the eastern rapid infiltration basins and two were located downgradient from the western rapid infiltration basins.