Kent County, Plainfield Township, State Disposal Superfund Site

Updated: January 8, 2020

MAP State Disposal Superfund SiteBackground

This site was a licensed waste disposal facility from 1966 to 1976. This is a State-led Superfund site. The study area is approximately 800 acres of wooded, agricultural, and residential properties. Waste Management of Michigan Inc., (WMMI) is the liable party for this site.

Recent Accomplishments

  • In November 2019, the second semi-annual groundwater sampling event was conducted. Sample results are not yet available.

Next Steps

  • EGLE will continue to follow-up on resident calls and emails regarding the site.
  • WMMI will work with EGLE to implement recommendations discussed during the recent meeting.
  • In February 2020, WMMI will submit the 2019 Annual Environmental Monitoring Report for EGLE’s review.

Residential Well Testing/Alternate Water Information

  • Most residents in the area are connected to the Plainfield Township municipal water supply system; however, EGLE staff identified 31 private residential wells adjacent to the contaminated groundwater plume from the State Disposal Landfill, Inc.
  • Of the residential wells sampled to date, 45 wells are non-detect and none are in exceedance of 70 ppt combined concentrations of PFOS and PFOA.
  • For additional information on residential well testing and results, visit the Frequently Asked Questions.
  • EGLE has sampled all municipal water supplies for PFAS. View the results for Plainfield Township.

Upcoming Community Engagement

  • None scheduled at this time.
Sampling: PFOS and PFOA Only

Type of Sample

Date Sampled

Number of Samples

Number of Results Received

Number of Non-detects

Number Between Non-detect and standard*

Number of > Standard

Drinking Water (Residential) Oct 3, 2016 -
Oct 16, 2018
54 54 45 9 0
Groundwater Oct 3, 2016 -
Apr 11, 2019
138 138 55 36 47
Surface Water Oct 3, 2016 8 8 6 2 0
Cumulative Oct 3, 2016 -
Apr 11, 2019
200 200 106 47 47

*Groundwater results are compared to EGLE Part 201 Criteria of 70 ppt PFOS+PFOA.
*Residential well results are compared to the USEPA Lifetime Health Advisory Level of 70 ppt PFOS+PFOA.
*Surface water and effluent results are compared to Rule 57 surface water quality values of 12 ppt for PFOS and 12,000 ppt for PFOA.

Sampling notes

  • Other PFAS analytes were detected in samples. There are no federal or state standards for these analytes.

State Disposal Superfund Site Historical Timeline

The site was a licensed waste disposal facility from 1966 until 1976, during which time residential, commercial, and other wastes were accepted. This is a State-led Superfund site. The study area is approximately 800 acres of wooded, agricultural, and residential properties. WMMI is the liable party for this site.

  • In 2016 as part of a USEPA municipal water supply testing initiative, PFAS was detected in Plainfield Township’s municipal water.
  • Most residents in the area are connected to the Plainfield Township municipal water supply system; however, staff from EGLE identified 31 private residential wells adjacent to the contaminated groundwater plume from the State Disposal Landfill, Inc.
    • During 2017 and 2018, WMMI, owner and operator of this site, collected 20 groundwater samples from private residential wells at 18 properties east and south of the landfill. One sample east of the landfill had 26 ppt PFOA.
    • EGLE sampled 11 additional residential wells east of the landfill. Two wells were under 10 ppt PFOS+PFOA; the remainder of the wells were non-detect. The possibility of other source areas separate from the State Disposal Landfill is being investigated.
    • Of the residential wells sampled to date, 45 wells are non-detect and none are in exceedance of 70 ppt combined concentrations of PFOS and PFOA.
  • In April 2018, WMMI installed five new vertical profile soil borings (the original monitoring wells were installed back in the 1970’s) to assist in determining the source of the contamination and potential impacts on surface water. EGLE staff may install additional groundwater monitoring wells to address possible data gaps.
    • PFAS concentrations above 70 ppt were present in groundwater migrating from the State Disposal Superfund Site.
    • PFAS was detected in the industrial pretreatment sampling for the State Disposal Superfund Site performed by EGLE WRD.
  • On December 11, 2018, WMMI installed an additional vertical aquifer sample boring to assist evaluation of PFAS in groundwater coming from the State Disposal Superfund Site. On that same day, EGLE staff observed a portion of the drilling activities performed by WMMI contractors.
  • EGLE is requesting WMMI perform additional hydrogeological investigation to evaluate groundwater contaminants from the State Disposal Landfill migrating near the Plainfield Versluis Wellfield.
  • On February 20, 2019, EGLE staff met with WMMI and discussed recent sampling activities.
  • On April 1, 2019, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) staff received the 2018 Annual Environmental Monitoring Report. On August 9, 2019, EGLE sent WMMI a formal letter requesting that WMMI perform additional hydrogeological investigation to delineate groundwater contaminants from State Disposal Landfill migrating near the Plainfield Versluis Wellfield.
  • On August 9, 2019, EGLE requested that WMMI perform additional hydrogeological investigation to delineate groundwater contaminants from State Disposal Landfill migrating near the Plainfield Versluis Wellfield.
  • On September 23, 2019, EGLE met with WMMI to discuss EGLE’s recommendations for further investigation at the site.