Muskegon County Wastewater Management System Metro Wastewater Treatment Plant (Muskegon, Muskegon County)
EGLE Site Lead: Sydney Ruhala, RuhalaS@Michigan.gov or 517-599-5356. Content last updated: May 20, 2022.
The Muskegon County Wastewater Management System Metro Wastewater Treatment Plant (MCWMS Metro WWTP) located at 698 North Maple Island Road, went into full operation in 1974. It is designed to treat 42 million gallons of wastewater per day. Treatment includes aeration cells, aerated settling cells, storage lagoons, spray irrigation of stabilized wastewater onto crops, underdrains to collect the irrigation water, and interception ditches to collect site leakage for treatment by rapid infiltration basins. The treated wastewater that is collected is discharged to the Muskegon River. Some of the uncollected wastewater discharges to the groundwater. Monitoring wells are installed within and surrounding the WWTP to monitor groundwater. Surface water and groundwater discharges are monitored in accordance with a National Pollutant Discharge Elimination System (NPDES) permit issued to Muskegon County.
EGLE’s Industrial Pretreatment Program (IPP) PFAS Initiative identified the MCWMS Metro WWTP as a site of concern due to the acceptance of leachate from the county-owned landfill located adjacent to the WWTP and wastewater from various industries and groundwater clean-ups containing PFAS. Since the initiative, Muskegon County has been working with sources to reduce PFAS. Due to elevated concentrations of PFAS in the storage lagoons and interceptor ditches, EGLE required that Muskegon County sample a portion of the WWTP’s monitoring wells for PFAS. Of the 23 monitoring wells evaluated, 3 exceeded the Part 201 groundwater cleanup criteria for PFOS and/or PFOA. The highest result from this sampling effort was 48 ppt PFOS and 42 ppt PFOA. Note that two of the monitoring wells exceeding the criteria are located within the approximately 11,000-acre WWTP site and one is located on the northwest site perimeter.
Estimated regional groundwater flow direction ranges between south, west, and north. A groundwater interception ditch surrounds the storage lagoons which is designed to capture shallow groundwater flow underneath the storage lagoons.
- On December 1, 2021, EGLE contractors collected samples of water from one additional residential drinking water well in Muskegon along a portion of White Road and North Maple Island Road (west of the Maple Island Estates Mobile Home Community). PFAS was not detected in the well.
- On December 7, 2021, Muskegon County submitted the Phase 2 PFAS Sampling Work Plan, which consists of additional groundwater monitoring well sampling around the WWTP’s lagoons and spray irrigation fields. The work plan was approved by EGLE on February 17, 2022. Work is scheduled to begin in Spring 2022.
- On March 29, 2022, EGLE collected samples of water from one additional residential drinking water well in Muskegon near the WWTP. PFAS was not detected in the well.
- EGLE will continue to work with Muskegon County Department of Public Works to determine the nature and extent of the PFAS plume.
Residential Well Testing/Alternate Water Information
- EGLE will continue to work with the Michigan Department of Health and Human Services (MDHHS) and Public Health Muskegon County 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
This table was updated to include all seven PFAS criteria effective 12/21/2020.
Type of Sample
Date Sampled (or Range)
Number of Sample Results Received
Number of Samples above Criteria
|Residential Wells||August 2021 - March 2022||8||0|
Groundwater Monitoring Wells
|November 2018 - July 2021||33||12|
* Residential well and groundwater monitoring well results are compared to EGLE Part 201 criteria for 7 PFAS compounds: PFOS (16 ppt), PFOA (8 ppt), PFNA (6 ppt), PFHxS (51 ppt), PFHxA (400,000 ppt), PFBS (420 ppt), and HFPO-DA (370 ppt).
- MCWMS Metro WWTP samples its final effluent for PFAS on a quarterly basis under the IPP PFAS initiative. Various wastewater samples from the treatment cells, storage lagoons and interceptor ditches have also been tested for PFAS.
- On October 19, 2018, EGLE sent a request to MCWMS Metro WWTP to sample for PFAS at groundwater monitoring wells near the storage lagoons.
- On January 17, 2019, EGLE received PFAS sampling results from MCWMS Metro WWTP for three groundwater monitoring wells. Two wells installed between the storage lagoons on the WWTP site were in exceedance of proposed MCLs for PFOA and PFOS.
- On February 13, 2019, EGLE received a letter from MCWMS Metro WWTP proposing a list of additional wells to sample for PFAS.
- On February 20, 2019, EGLE sent MCWMS Metro WWTP a letter requesting additional sampling of select groundwater monitoring wells around the storage lagoons to better understand potential PFAS impacts to groundwater.
- On April 23, 2019, MCWMS Metro WWTP submitted PFAS sampling results for 17 groundwater monitoring wells on the East and Southern sides of the storage lagoons. Only one well on the northwest site perimeter had detections above Part 201 criteria for PFOA which became effective on August 3, 2020.
- On September 28, 2020, MPART hosted a PFAS Regional Information Webinar for the Grand Rapids Region where details of this site investigation were presented.
- On April 29, 2021, EGLE sent MCWMS Metro WWTP a letter requesting additional sampling of select groundwater monitoring wells around the storage lagoons to better understand potential PFAS impacts to groundwater as well as recommended a groundwater elevation study to better understand groundwater flow direction.
- On June 11, 2021, EGLE approved the Phase 1 Work Plan for additional groundwater monitoring well sampling and a groundwater elevation study. The Phase 1 Work Plan will be competed in 90 days and MCWMS Metro WWTP will submit a Phase 2 Work Plan based on results.
- On July 8, 2021, EGLE went door to door in Muskegon along a portion of White Road and N Maple Island Road (west of the Maple Island Estates Mobile Home Community) to deliver access agreement forms to 14 homes for residential well sampling.
- On July 13, 2021, Muskegon County sampled 10 groundwater monitoring wells for PFAS as part of their Phase 1 Work Plan.
- On August 10, 2021, Muskegon County submitted the Phase 1 Monitoring Well Sampling Report. A total of 10 groundwater monitoring wells were sampled for PFAS. Nine wells had detections above groundwater clean-up criteria for PFOA and 2 exceeded for PFOS.
- On August 11, 2021, Muskegon County submitted the Phase 1 Groundwater Elevation Study Report.
- On August 11, 2021, EGLE contractors collected samples of water from 6 residential drinking water wells in Muskegon along a portion of White Road and North Maple Island Road (west of the Maple Island Estates Mobile Home Community). Of the 6 wells, 4 were non-detect for PFAS. PFAS was detected in 2 of the wells but below drinking water criteria.
- On October 22, 2021, Muskegon County submitted the revised Phase 1 Groundwater Elevation Study Report.