Central Sanitary Landfill, Pierson, Montcalm County

PFOA + PFOS Sampling Results - Central Sanitary LandfillLast Updated: February 16, 2021


Central Sanitary Landfill (CSL) is located 2/3 of a mile northwest of the village of Pierson. Central Sanitary Landfill Inc. is a subsidiary of Republic Services, Inc., (Republic). The facility is a Type II landfill which accepts municipal solid waste. PFAS investigation began when it was discovered that CSL accepted tannery wastes from Wolverine World Wide, Inc., in Rockford, Michigan which may have contained high levels of PFAS. Groundwater contamination is present from historic waste management activities. CSL operates a groundwater remediation system to treat contaminants from the landfill that have leaked into the groundwater. 

Except for a small portion of the landfill in the north, which is the oldest portion of the site, the landfill is almost completely double-lined. There is a monitored leak detection system installed between the liners. The double liner system with leak detection is designed to detect and correct any leaks before any groundwater contamination can occur.

Recent Accomplishments

  • On December 8, 2021, CSL met with EGLE to discuss the best strategy for defining PFAS impacts to groundwater northeast of the Landfill.
  • On January 26, 2021, CSL submitted 4th quarter PFAS monitoring data for 22 monitoring wells to EGLE.  The highest PFOA was 920 ppt collected from monitor well P-37, the highest PFOS results was 230 ppt collected from monitoring well P-11, the highest PFBS results was 2,100 ppt collected from monitoring well P-30, the highest PFHxS results was 100 ppt collected from monitoring well MW-35S, the highest PFHxA results was 2,600 ppt collected from monitoring well P-37, the highest PFNA results was 3.8 ppt collected from monitoring well P-11.

Next Steps

  • CSL is working on obtaining access to private properties to install additional PFAS groundwater monitoring wells.

Residential Well Testing/Alternate Water Information

  • 26 residential wells have been tested by CSL; six residents were resampled.
  • Three households have been provided a filter by CSL and filters were offered to any resident in the Phase I or II investigation area who had a PFAS detection as a precaution by the Mid-Michigan District Health Department.
  • For additional information on residential well testing and results, visit the Frequently Asked Questions.

Upcoming Community Engagement

  • None scheduled at this time.

Sampling Results Summary
This chart reflects data received after 8/3/2020.  Data prior to 8/3/2020 is reflected in the timeline below. 
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

Groundwater Monitoring Wells

August 12, 2020 - November 10, 2020 66 60

* 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).

Sampling notes

  • On August 3, 2020, new Part 201 Criteria went into effect.  Historical sampling data compared to Part 201 Criteria >70 is captured in the historical timeline below.
  • Other PFAS analytes were detected in samples. There are no federal or state standards for these analytes.
  • 22 monitoring wells are sampled quarterly per the CSL approved workplan; the totals are included above

Historical Timeline

  • In November 2017, Wolverine World Wide Inc., identified CSL as a location where they disposed of various tannery wastes from approximately 1984-2009. These wastes likely contained high levels of PFAS.
  • From December 2017-February 2018, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) proactively required CSL to develop a workplan to address several issues identified at the site, including the conceptual site model and potential PFAS contamination of groundwater at CSL.
  • On February 27 and 28, 2018, CSL collected the first round of PFAS samples from 10 monitoring wells around the landfill. Monitoring wells are used to detect contaminants and signs of leakage to the groundwater around the landfill.
  • In March 2018, CSL voluntarily collected samples from two non-potable (non-drinking water) supply wells which they use on-site for flushing toilets, washing hands and other maintenance activities.
  • On April 13, 2018, EGLE learned that 5 of the 12 onsite monitoring wells that were sampled contained PFAS that exceeded the 70 part per trillion (ppt) lifetime health advisory (LHA) and immediately began working with CSL, the Michigan Department of Health and Human Services (MDHHS) and the Mid-Michigan District Health Department (MMDHD) to develop a phased sampling plan of domestic wells close to and in the directions of groundwater flow from the landfill to ensure that public health was protected.
  • In early May 2018, CSL sampled 12 additional monitoring wells on landfill properties and the results were submitted mid-June to EGLE. One of the 12 samples contained PFAS higher than the LHA of 70 ppt.
  • On May 2 and 3, 2018, CSL began the Phase 1 of the plan, which included sampling 19 properties, two of which are Type II public supply wells (wells that serve more people than a single household, such as a business that uses well water). CSL provided bottled water to the properties while sample results were pending. 18 properties were sampled; 1 resident refused to be sampled. Results of this sampling were submitted to EGLE on May 29, 2018. Based on the Phase 1 results, it was determined that several additional properties should be sampled (Phase 2).
  • On June 7, 2018, CSL completed Phase 2 of drinking water well sampling.  Phase 2 testing included seven additional properties located near the northeast corner of the landfill.
  • June 18, 2018, EGLE, MDHHS, MMDHD, along with CSL, hosted a community open house and public meeting at Tri County High School in Howard City, Michigan.
  • On July 9, 2018, CSL submitted Phase 2 sampling results to EGLE.
  • In October-November 2018, CSL installed seven new groundwater monitoring wells to help better delineate PFAS in the groundwater.
  • On October 22-23, 2018, CSL sampled nine additional landfill monitoring wells to help better delineate PFAS in the groundwater.
  • On November 13, 2018, EGLE received results from one new residential well and one residential well resample from CSL.
  • On November 20, 2018, CSL completed the first quarterly PFAS monitoring event at select monitoring wells around the landfill.
  • On December 17, 2018, CSL sampled two new groundwater monitoring wells on the west side of US 131 near the landfill.
  • On December 18, 2018, EGLE received results from CSL for 9 samples taken from wells in the NE corner of the landfill property and from newly installed wells on the east side of the landfill.
  • On December 19, 2018, CSL installed column testing equipment in the groundwater remediation shed to start running on-site pilot testing for granular activated carbon (GAC) efficiency.
  • On January 11, 2018, EGLE received results from CSL for 11 samples as a part of CSLs first quarterly PFAS monitoring event.
  • On February 05, 2019, EGLE received results from CSL for the two new monitoring wells installed in the North West corner of the landfill, just west of US-131.
  • On February 20, 2019 CSL collected its second round of quarterly PFAS sampling at 13 monitoring wells.  Two new wells were added to the quarterly sampling list due to elevated PFAS levels in two new monitoring wells installed west of US-131.
  • In March 2019, CSL completed groundwater treatment pilot testing and is working on drafting a report to summarize next steps and treatment strategy.
  • On April 29 through May 3, 2019, CSL installed one shallow and one deep groundwater monitoring well West of the South half of the landfill on the West side of U.S. 131.
  • On May 14, 2019, CSL sampled the two new wells West of US-131 for PFAS. Results are expected the first half of June 2019. CSL also submitted a report summarizing all PFAS work which has been completed to date.
  • On May 15, 2019, CSL submitted its third quarter of routine PFAS groundwater monitoring to monitor any trends that may be occuring.
  • On June 28, 2019, EGLE received PFAS results from the two new wells west of US-131 and the second quarter PFAS sampling results.
  • July 24, 2019, EGLE and CSL met to discuss progress thus far.  CSL presented PFAS treatment system pilot study data and presented information on what they propose to do next in the investigation. 
  • On August 29, 2019, CSL submitted a workplan to continue defining PFAS in groundwater northwest and northeast of the landfill.
  • On November 13, 2019, CSL provided quarterly monitoring results for 16 wells and 5 additional wells to better define PFAS impacts to groundwater on landfill property. 
  • On November 25, 2019, CSL resampled two residential homes impacted by PFAS to monitor concentration changes over time. 
  • On January 8, 2020, CSL submitted PFAS retesting results for two homes which have been impacted by PFAS.  Retesting was completed to monitor concentration changes over time.  
  • On January 16, 2020, CSL submitted 4th quarter PFAS monitoring data for 21 groundwater monitoring wells.  CSL also sampled one new well for PFAS to better define PFAS impacted groundwater onsite.  Data is reflected on the sampling chart.
    • Historical Sampling Table: data is reflective of criteria prior to 8/3/2020:
      PFOS + PFOA Only
      This table reflects data received prior to 8/3/2020.

      Type of Sample

      Date Sampled

      Number of Samples

      Number of Results Received

      Number of Non-detects

      Number of Detections Below Standard*

      Number of Detections Greater Than Standard*

      Drinking Water (Residential, Type II) May 2, 2018 -
      Oct 24, 2018
      31 31 23 7 1
      Effluent (Air Stripper) May 17, 2018 -
      Jul 18, 2018
      2 2 0 0 2


      Feb 27, 2018 -
      Jan 2019
      137 137 18 59 60


        170 170 41 66 63

      *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.
      *Residential well results are compared to the EPA Lifetime Health Advisory Level of 70 ppt PFOS+PFOA.
      *Groundwater results are compared to EGLE Part 201 Criteria of 70 ppt PFOS+PFOA. 

    • Related Sampling Notes

      • Ε¦The groundwater results in the table above represent 34 unique groundwater wells; 21 of these wells are re-sampled quarterly and are included in the totals above.
      • Non-detect means that the lab did not detect or find PFAS in the water sample at or above the reporting limit.
      • Air Stripper Influent was also sampled.
  • On August 28, 2020, CSL submitted 2nd quarter PFAS monitoring data for 22 monitoring wells to EGLE. The highest PFOA was 760 ppt collected from monitor well P-37 and the highest PFOS result was 260 ppt collected from monitoring well P-11.
  • On September 28, 2020, EGLE had a conference call with CSL to discuss site progress with the groundwater treatment system and on gaining access to private land to install additional groundwater monitoring wells. CSL informed EGLE the installation of the PFAS groundwater treatment system is delayed because of COVID-19.
  • On October 5, 2020, CSL submitted 3rd quarter PFAS monitoring data for 22 monitoring wells to EGLE.  The highest PFOA was 840 ppt collected from monitor well P-37 and the highest PFOS result was 230 ppt collected from monitoring well P-11.   

June 18, 2018 Public Meeting Documents

April 26, 2018 Public Meeting Documents

Health Information

Agency for Toxic Substances and Disease Registry