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Willow Run Airport (Ypsilanti, Wayne and Washtenaw Counties)

EGLE Site Lead: Kevin Wojciechowski, WojciechowskiK@Michigan.gov or 586-623-2948. Webpage last updated April 7, 2021.

Background

Willow Run Airport is a general aviation airfield with all associated facilities, providing service for air cargo, charter airlines, and a flying school. The airport is located at 801 Willow Run Airport and encompasses approximately 2,600 acres north of Interstate 94 and west of Beck Road in Ypsilanti. A large portion of the airport property is in Wayne County and a small portion in Washtenaw County.

On April 30, 2019 surface water samples were collected from Willow Run Creek southwest of the property as part of stream monitoring performed by EGLE. Of the samples collected from Willow Run Creek, two sampling locations near Willow Run Airport exceeded water quality standards for PFOS. As follow-up action, Willow Run Airport was required to perform PFAS sampling at each storm water discharge point. The highest PFOS detection was 240 ppt. In July 2020, due to redevelopment of an airplane hangar on the northeast part of the property, groundwater samples were collected from the northeastern portion of the airport property.

Groundwater flow is in the south-southeast direction on the southern half of the airport. Groundwater flow is anticipated to be to the northeast in the northern part of the property where PFAS was detected. The Willow Run Airport is in the Huron River and Rouge River watersheds.

In 2018 the Michigan Department of Health and Human Services issued a 'Do Not Eat' fish advisory for all fish in the Huron River in Livingston, Oakland, Washtenaw, Wayne, and Monroe Counties. Fish samples were collected by EGLE Surface Water Assessment Section.

 

Willow Run Airport Map

Recent Accomplishments

  • In the fall of 2020, LimnoTech, Willow Run Airport's contractor, began Phase I of the investigation.
  • On October 7, 2020, EGLE received groundwater PFAS results from the July 2020 sampling event. The highest PFOS detection was 1,700 ppt and the highest PFOA was 150 ppt.
  • On March 10, 2021, EGLE received soil and groundwater PFAS results from the September and November Phase 1 sampling event. The highest PFOS detection was 16,000 ppt and the highest PFOA was 990 ppt in groundwater.

Next Steps

  • EGLE, working with Michigan Department of Health and Human Services (MDHHS), Wayne County Health Department and Washtenaw County Health Department, identified 35 nearby water wells. EGLE, MDHHS, and Wayne and Washtenaw Counties will continue to assess the need for drinking water sampling as more PFAS groundwater data is collected in 2021.
  • Willow Run Airport/LimnoTech will continue to implement the approved PFAS grant workplan under MDOT.
  • Willow Run Airport/LimnoTech will finalize the Phase 2 investigation, which included additional sampling. EGLE anticipates receiving the Phase 2 investigation report in April 2021.

Residential Well Testing

  • Based on current PFAS groundwater data, there are no plans at this time to sample residential wells. EGLE, MDHHS, Wayne County Health Department and Washtenaw County Health Department will evaluate data as it becomes available to continue to assess if residential well sampling is necessary.

Upcoming Community Engagement

  • None scheduled at this time.

Sampling Results Summary

Type of Sample

Date Sampled (or Range)

Number of Sample Results Received

Number of Samples Above Criteria*

Groundwater Monitoring Wells

July - November 2020  20 17
 Surface Water April 2019   23 11 
*Residential well and groundwater monitoring well results are compared to EGLE Part 201 criteria for 7 PFAS compounds effective 12/21/2020: PFOS (16 ppt), PFOA (8 ppt), PFNA (6 ppt), PFHxS (51 ppt), PFHxA (400,000 ppt), PFBS (420 ppt), and HFPO-DA (370 ppt).
*Surface water samples are compared to Rule 57 non-drinking water values of 12 ppt for PFOS and 12,000 ppt for PFOA.

       Sampling Notes

  • Surface water samples were collected and analyzed for PFAS as part of ongoing investigation in the Rouge River and Huron River watersheds. In October 2020 samples were collected from Horner Drain downstream of the airport. Samples exceeded Water Quality Standards at 429 ppt for PFOS.

Historical Timeline

    • In July 2020, due to redevelopment of an airplane hangar, eight groundwater samples were collected for PFAS analysis from the northeastern portion of the airport property.
    • On September 11, 2020, Michigan Department of Transportation (MDOT) approved a $250,000 grant to conduct a PFAS investigation of two known areas where AFFF was released on the airport property.
    • In the fall of 2020, LimnoTech, Willow Run Airport's contractor, began Phase I of the investigation.
    • On October 7, 2020, EGLE received groundwater PFAS results from the July 2020 sampling event. The highest PFOS detection was 1,700 ppt and the highest PFOA was 150 ppt.
    • On March 10, 2021, EGLE received soil and groundwater PFAS results from the September and November Phase 1 sampling event. The highest PFOS detection was 16,000 ppt and the highest PFOA was 990 ppt in groundwater.