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South Macomb Disposal Authority Landfills 9/9A (Macomb, Macomb County)

EGLE Site Lead: Mellisa Powers-Taylor, PowersTaylorM@Michigan.gov or 517-388-0795. Webpage last updated April 14, 2021.

Background

The South Macomb Disposal Authority (SMDA) Landfills 9 and 9A located at 24 Mile Road, is comprised of two adjacent municipal waste landfills, Landfill 9 and Landfill 9A, that were utilized for the disposal of municipal wastes from 1968 to 1975. The sites were not adequately covered or lined to prevent contamination from leaving the landfills and entering groundwater. Local aquifers are contaminated with landfill leachate.

Great Lakes Water Authority (GLWA) required the South Macomb Disposal Authority to collect PFAS from the influent and effluent of their leachate and groundwater collection system as part of their permit to discharge to the GLWA system.  EGLE initiated discussions about PFAS sampling in the groundwater wells around the landfills in July 2019.  SMDA informed EGLE that they had been collecting PFAS samples from the water treatment system and EGLE requested a copy of the laboratory reports.  The laboratory reports showed that PFOA and PFOS was present in leachate above 70 parts per trillion.  EGLE requested that SMDA collect groundwater samples for PFAS.  The first round of groundwater samples were collected during the June 2020 sampling event.  EGLE split 3 groundwater samples and the results showed PFOA above the groundwater cleanup criteria.

The groundwater in Aquifer 1 flows from the northeast corner of Landfill 9 to the south east.  The groundwater in Aquifer 2 flows from the northeast corner of Landfill 9 to the northeast, southeast, and southwest.  Groundwater in Aquifer 2 additionally flows toward the site from the northwest.  Groundwater in Aquifer 3 flows inward towards the center of Landfill 9 from the southwest, west, northwest, north, northeast, and east. 

Potential receptors in the area include potential drinking water wells located adjacent to the site.  

South Macomb Disposal Authority Landfills 9/9A Map

Recent Accomplishments

  • On March 9, 2021, EGLE sent the SMDA a letter formally requesting that the SMDA sample nine residential wells for PFAS.
  • On March 29, 2021, the SMDA sent EGLE a letter agreeing to sample nine residential wells for PFAS.  

Next Steps

  • EGLE will mail letters to residents informing them of the SMDA's intent to request access for PFAS sampling by April 30, 2021.
  • EGLE will hold a Public Meeting on May 12, 2021, regarding the upcoming residential well sampling. 
  • SMDA will send a Residential Well Sampling Plan and updated Quality Assurance Project Plan for EGLE review and approval by May 13, 2021. 
  • The SMDA will send letters and access agreements to residents by May 17, 2021.

Residential Well Testing/Alternate Water Information

  • EGLE and the local health department have identified residential wells nearby that have historically been tested for site related contaminants.  The SMDA has agreed to sample the residential wells nearby the site. 

Upcoming Community Engagement

  • A public meeting is scheduled for May 12, 2021 from 6:00-7:30 pm. For more information on this event visit Michigan.gov/MPARTEvents.

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*

Groundwater Monitoring Wells

June 3 - 10, 2020 - December 2, 2020 40 16

*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

  • None at this time.
 

Historical Timeline

    • On October 24, 2019, EGLE Remediation and Redevelopment Division (RRD) Superfund Section staff sent SMDA a request to prepare a PFAS sampling work plan and quality assurance project plan (QAPP) to sample groundwater around the landfill for PFAS. 
    • On May 26, 2020, EGLE RRD Superfund Section approved the PFAS Sampling Work Plan with the understanding that the QAPP was still under review and not yet approved by EGLE RRD Superfund.
    • From June 3-12, 2020 SMDA, their consultants Anderson, Eckstein, Westrick and Associates (AEW) and TRC Companies (TRC), along with the analytical laboratory Midwest Analytical Services (MAS) collected groundwater PFAS samples. The samples were sent to Test America/Eurofins Laboratory for analysis.
    • On June 3, 2020, EGLE staff collected split samples at three wells.  The analytical samples were sent to Vista Laboratories for analysis.
    • On June 22, 2020, EGLE RRD Superfund Section received the laboratory report from Vista Analytical.
    • On June 29, 2020, EGLE RRD Superfund Section staff notified the Macomb County Health Department and the Michigan Department of Health and Human Services that PFOA concentrations reports for 2 monitoring well locations sampled by EGLE were above the cleanup criteria for PFOA.  The highest result was 43.3 ppt PFOA.
    • On August 27, 2020, EGLE met with SMDA and requested that SMDA sample residential wells identified by EGLE and the local health department.
    • On September 15, 2020, there was a public meeting discussing new PFAS Sites, including SMDA Landfills 9/9A. 
    • On October 7, 2020, EGLE submitted a draft of the Public Health Action Plan to DHHS for review. 
    • The SMDA and their consultants collected a second round of PFAS samples from site monitoring wells the week of November 30, 2020.
    • On December 29, 2020, EGLE and DHHS agreed to a final draft of the Public Health Action Plan.