Washtenaw County, Salem Township, Arbor Hills Landfill, Inc.

Arbor Hills Landfill Inc PFOA + PFOS Sampling MapUpdated: March 31, 2020

Background

Arbor Hills Landfill (Arbor Hills) is an active landfill located at the corner of Napier Road and Six Mile Road owned and operated by Advanced Disposal Services.  Samples were collected from this site in response to a letter from the Michigan Department of Environment, Great Lakes, and Energy (EGLE), requesting PFAS sampling of groundwater at a subset of site monitoring wells, as well as a representative leachate sampling.  The purpose of the PFAS sampling was to provide information on the composition of groundwater and leachate at the site.

Groundwater flows south-southeast; nearby surface water flows to the east.  Surface water from the site drains to Johnson Creek southeast of the site and into the middle branch of the Rouge River.

Recent Accomplishments

  • In April 2019, EGLE requested that Arbor Hills collect PFAS water samples based on MPART initiatives.
  • On June 11, 2019, Arbor Hills collected five groundwater samples from on-site monitoring wells and one leachate sample from the primary leachate collection system.  The highest groundwater PFOS+PFOA result was 102 ppt from monitoring well, MPB-393.  No other monitoring wells results exceeded the EGLE Part 201 drinking water criteria for PFOS+PFOA (70 ppt).
  • On August 6, 2019, Arbor Hills collected a confirmation groundwater sample from monitoring well MPB-393.  The result was 124 ppt PFOS+PFOA.  In September 2019, EGLE received a summary of the PFAS sampling results from Arbor Hills.
  • In October 2019, EGLE reviewed the report prepared by Arbor Hills showing the PFAS data, and determined the next steps, including recommendations that Arbor Hills prepare a work plan to collect additional information related to PFAS.
  • On January 23, 2020, EGLE staff, Michigan Department of Health and Human Services (DHHS) and local health departments discussed the Arbor Hill’s PFAS results and potential residential well sampling, as well as the preparation of a public heath action plan to address potential issues and concerns, and proposed a Town Hall meeting to discuss PFAS around Arbor Hills.  Another planning call was completed on February 6, 2020 to finalize the residential sampling plan and discuss next steps.
  • On February 26, 2020, seven residential water samples and one Type II water supply sample were collected for PFAS.  The results showed that none of the water tested were above the Part 201 for drinking water criteria or currently proposed MCL criteria. 
  • In March 2020, MPART recorded a webinar discussing PFAS around Arbor Hills. 

Next Steps

  • EGLE will continue to review the Arbor Hills PFAS investigation activities to define the potential source and extent of the PFAS, both vertically and horizontally; to identify and evaluate potential receptors; and subsequent actions, if necessary.  The work plan was provided to EGLE on February 21, 2020, for review.  EGLE agreed with the activities and requested additional activities on February 24, 2020.

Residential Well Testing/Alternate Water Information

  • Municipal water is available in much of the area surrounding the landfill. However, several private wells are located to the west and south of the landfill.
  • Private wells were identified for sampling, and sampled, due to their proximity to Arbor Hills and well characteristics (e.g., within ½ mile, shallow screen, and/or unknown geology).  This includes a Type II well serving the landfill, and seven private residential wells.
  • PFAS results for the seven residential wells and one Type II well were below the Part 201 criteria for drinking water.  
  • For additional information on residential well testing and results, visit the Frequently Asked Questions.

Upcoming Community Engagement

Sampling: PFOS and PFOA Only

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 Wells and Type II Wells) Feb 2020 8 8 8 0 0
Groundwater June - Aug 2019 6 6 1 3 2
Cumulative
 
14 14 9 3 2

*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.

Sampling notes

  • PFOS+PFOA result of 1,160 ppt was found in the leachate sample collected on June 11, 2019. There are no federal or state standards PFAS in leachate. 
  • One residential well drinking water sample had 4 ppt PFHxA, this is significantly below the draft MCLs of 400,000 ppt for PFHxA.

Historical Timeline

  • No historical timeline at this time.