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Camp Grayling - Cantonment/Lake Margrethe (Grayling, Crawford County)

Camp Grayling - Cantonment/Lake Margrethe (Grayling, Crawford County)

Background

Cantonment is a roughly 1,000-acre area that borders the southern end of Lake Margrethe and is located approximately 3 miles southwest of GAAF at 1000 M-93, Howe Rd. AFFF was used and stored for training and fire-fighting activities during the 1970s-80s. Cantonment currently contains support facilities and recreational areas for military activities. Lake Margrethe is used recreationally and is surrounded by residential properties. PFAS was first discovered near Cantonment following an EGLE effort to sample foam on Lake Margrethe in 2018. EGLE conducted private drinking water well sampling shortly after, and since, EGLE, Army National Guard, and MDHHS have sampled over 800 private drinking water wells combined.

Following the CERCLA process, the Army National Guard completed the Preliminary Assessment in 2018 and the Site Inspection in 2021. The Army National Guard is currently completing the Remedial Investigation, which includes groundwater, soil, surface water, sediment, and porewater sampling.

Content updated March 2026.

Lake Margrethe advisories

EGLE tested foam on the surface of Lake Margrethe in 2018, 2019, and 2020, and results found elevated levels of PFAS in the lake foam. EGLE is diligently working with ARNG to determine discharge points for the PFAS entering the lake from Cantonment. Skin contact with foam is not considered harmful. As a precaution, District Health Department #10 and MDHHS recommend recreators avoid foam and rinse off if foam is touched to avoid prolonged contact with the skin. Learn more about PFAS foam on lakes and streams.

Additionally, MDHHS has issued Eat Safe Fish guidelines for fish caught from Lake Margrethe and the Au Sable River upstream of the Mio Dam as they relate to PFOS, mercury, and more.

Anticipated activities

EGLE will continue to review incoming data, Army National Guard reports, and Army National Guard workplans in a timely manner to facilitate ongoing work being completed by the Army National Guard.

A summary of all data collected for the Remedial Investigation is expected to be released by the Army National Guard in Spring 2026. The Draft Remedial Investigation Report is expected to be available for EGLE review by the Army National Guard in Fall 2026.

Lake Margrethe Map Preview

PFAS concentration map

View an aerial view of the PFOS in groundwater at the site.

Expand the map

Other Camp Grayling site locations

  • Grayling Army Airfield (GAAF)

  • MATES

  • North Post/South Post

Return to Camp Grayling overview

EGLE site lead

Summer Cox, CoxS12@Michigan.gov or 517-275-2805.

Historical Timeline

    • In October 2017, EGLE received a picture and video of foam at Lake Margrethe from a part-time resident.
    • In October 2017, EGLE responded to the October 2017 information by collecting four surface water samples, three foam samples, one residential well sample, and a hand pump well sample at the state forest campground.
      • Foam sample results ranged from 2,341 ppt to 24,810 ppt PFOS+PFOA.
      • The residential well sample was non-detect for PFOS+PFOA, as was the sample form the hand pump well at the state forest campground.
    • On November 27, 2017, EGLE hosted a public meeting for the community. One conference call has been held with local stakeholders.
    • On May 29, 2018, EGLE hosted a meeting to update local officials on the status of the investigation.
    • On June 5, 2018, EGLE hosted a public meeting for the community.
    • On July 21, 2018, EGLE, Michigan Department of Military and Veterans Affairs, and District Health Department #10 attended the Lake Margrethe Property Owners Association meeting at Grayling Township Hall.
    • Between August 6 and 23, 2018, 14 monitoring wells were installed at five locations on the southeast side of Lake Margrethe. Data has been received by EGLE and maps were developed, and next steps determined.
    • On September 18 and 19, 2018, EGLE used a drone equipped with an infrared camera to locate potential springs and groundwater seeps entering the lake.
    • On October 8 and 9, 2018, the drone was flown again to verify seeps and collect surface water and pore water samples. Pore water is locations where groundwater enters from the bottom of the lake. Nine pore water and seven surface water sample were collected. Currently, data is being evaluated and mapped so next steps can be determined. A technical report will be generated in March 2019
    • On December 11, 2018, an open house and public meeting were held.
    • On February 15, 2019, AECOM completed the 2nd round of RI groundwater monitoring.
    • On April 5, 2019, AECOM submitted the Remedial Investigation (RI) Report.
    • On June 4-5, 2019 EGLE resampled pore water, as well as sediment and surface water, from groundwater seeps at Lake Margrethe.
    • On June 5, 2019, there was a Restoration Advisory Board community meeting for the Grayling Area to learn about the RAB process, how a RAB functions, and the change to fill out a Community Member Interest Form. Applications were due by June 10 and the first RAB meeting will be announced this coming week.
    • A Tech Memo summarizing EGLE's offsite investigation results has been posted to the MPART website.
    • The Army National Guard hosted an open public meeting from 7:30-8:30 on June 25, 2019 at Kirtland Community College, 4800 W 4 Mile Rd, Grayling, to discuss plans to provide alternative drinking water to property owners with wells over 70 ppt of PFOA and PFOS.
    • EGLE held a Town Hall PFAS Informational Meeting on August 1, 2019 at Kirtland Community College to present results of recent environmental investigations. 
    • On July 31, 2019, the first meeting of the Camp Grayling Restoration Advisory Board was held from 10:00am - 12:00pm at Kirtland Community College - Grayling Campus, 4800 W 4 Mile Road, Grayling MI 49738. It included the organization of the new Restoration Advisory Board and other set-up functions. This meeting was open to the public.
    • On July 31, 2019, there was an Interoffice Communication from EGLE Eustice to EGLE Bon re: Camp Grayling Lake Margrethe Sampling Data Package.
    • On August 1, 2019, a Town Hall PFAS Informational Meeting was held at Kirtland Community College, 4800 W 4 Mile Rd, Grayling. An open house was from 4:30-6:00 pm, followed by a presentation of recent investigations from 6:00-7:30.
    • A Restoration Advisory Board (RAB) Meeting was held on October 7, 2019. The meeting focused primarily on developing RAB meeting operating procedures. Updates on progress were given by the DMVA, DNR, and EGLE. A presentation on regional hydrogeology was also given by EGLE.
    • On October 2, 2019, one foam sample was collected near the DNR boat launch.
    • Phase II of the Remedial Investigation was completed on October 8, 2019.
    • On November 6, 2019, a Restoration Advisory Board (RAB) Meeting was held. The meeting focused primarily on finalizing RAB meeting operating procedures and RAB communication with the public. Progress updates were given by the DMVA and EGLE. A presentation on the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process was given by DMVA. 
    • On December 11, 2019, a Restoration Advisory Board (RAB) Meeting was held. Progress updates were given by the DMVA and EGLE. A presentation on the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process was given by DMVA. Eric Keller, Regional Director for Senator Gary Peters, gave an update on PFAS at the federal level.
    • On December 12, 2019, AECOM completed the fourth quarterly groundwater sampling event.
    • On January 13, 2020, a Camp Grayling Restoration Advisory Board (RAB) meeting was held. Progress updates were given by DMVA, EGLE and DHHS. Sesha Kallakuri (MDHHS) gave a presentation on risk assessment and DHHS Drinking Water Screening Levels. The RAB members continued to develop their outreach and communications plans.
    • On February 20, 2020, a Camp Grayling Restoration Advisory Board (RAB) meeting was held. Progress updates were given by DMVA, EGLE and DHHS. Recent and future RAB outreach was discussed and the final RAB brochure was released. 
    • On March 31, 2020 AECOM completed Phase II quarterly monitoring well sampling.
    • On May 27, 2020, a virtual Restoration Advisory Board (RAB) was held. Progress updates were given by DMVA, DHHS, and EGLE.
    • On June 15, 2020, AECOM completed the June 2020 quarterly groundwater sampling event.
    • On July 22, 2020, a Camp Grayling Restoration Advisory Board (RAB) Virtual Meeting was held. Updates were given by DMVA, DHHS, and EGLE.
    • On September 24, 2020, a virtual Restoration Advisory Board (RAB) was held. Progress updates were given by DMVA, DHHS, and EGLE.
    • On September 30, 2020, AECOM completed the September 2020 quarterly groundwater sampling event.
    • On October 5, 2020, DHHS finished the first round of drinking water well resampling. 
    • On December 1, 2020, a virtual Restoration Advisory Board (RAB) was held. Progress updates were given by the Army National Guard, the Department of Military and Veterans Affairs (DMVA), the Department of Environment, Great Lakes, and Energy (EGLE), and the Department of Health and Human Services (DHHS).
    • On January 5-7, 2021, AECOM completed a quarterly groundwater sampling event.
    • On January 28, 2021, a virtual Restoration Advisory Board (RAB) was held. Progress updates were given by the Army National Guard, the Department of Military and Veterans Affairs (DMVA), the Department of Environment, Great Lakes, and Energy (EGLE), and the Department of Health and Human Services (DHHS).
    • On March 26, 2021, a virtual Restoration Advisory Board (RAB) was held. Progress updates were given by the Army National Guard, the Department of Military and Veterans Affairs (DMVA), the Department of Environment, Great Lakes, and Energy (EGLE), and the Department of Health and Human Services (DHHS).
    • On March 17, 2021, DHHS mailed the first round of drinking water well resampling results to well owners.
    • On March 29-31, 2021, AECOM completed a quarterly groundwater sampling event. 
    • On April 26, 2021, a virtual town hall for Camp Grayling PFAS sites was held. The purpose of this online public meeting was to update the community about the on-going PFAS investigations and drinking water well resampling efforts.
    • On May 11, 2021, The Department of Health and Human Services (DHHS) announced that a second round of resampling of residential drinking water wells would begin.
    • On June 9, 2021, a Grayling Restoration Advisory Board (RAB) Meeting was held.
    • On August 20, 2021, EGLE’s contractor finished sampling of pore and surface water at Lake Margrethe. Results will be shared when available. 
    • On August 25, 2021, a Grayling Restoration Advisory Board (RAB) Meeting was held.
    • On August 26, 2021, EGLE sent a Compliance Communication regarding wastewater sampling at the Cantonment wastewater treatment plant.
    • On September 9, 2021, MPART hosted a virtual town hall. Updates were presented by Michigan Department of Environment, Great Lakes, and Energy (EGLE), Michigan Department of Health and Human Services (MDHHS), Department of Military and Veteran Affairs (DMVA), and Army National Guard (ARNG).
    • On October 29, 2021, DMVA sent a response to EGLE's August 26, 2021, Compliance Communication regarding wastewater sampling at the Cantonment wastewater treatment plant.
    • On November 2, 2021, a Grayling Restoration Advisory Board (RAB) Meeting was held. EGLE's Lake Margrethe surface and pore water sampling results from August 2021 were presented. DMVA/ARNG gave updates on cantonment wastewater and stormwater sampling. DHHS gave an update on residential resampling.
    • On December 7, 2021, DMVA sent results of a Short-Term Stormwater Characterization Study. Two discharge locations of the stormwater system exceeded surface water criteria for PFOS (12 ppt). The highest result was 439 ppt. Results had previously been shared at the September 9, 2021, Town Hall.
    • On February 1, 2022, a Grayling Restoration Advisory Board (RAB) Meeting was held. DMVA presented an update to the Short-Term Storm Water Characterization Study.
    • On February 1 - 2, 2022, EGLE’s contractor, AECOM collected groundwater samples from existing monitoring wells.
    • On May 10, 2022, a Camp Grayling Public Meeting was held at Kirtland Community College. PFAS investigation updates were given by EGLE, ARNG, and DHHS. 
    • On May 9-13, 2022, EGLE’s contractor collected spring and surface water samples from Lake Margrethe.
    • On July 13, 2022, a Restoration Advisory Board meeting was held at Grayling Township Hall. 
    • On July 18-22, 2022, EGLE’s contractor completed a round of biannual sampling from monitoring wells. 
    • On July 25, 2022, EGLE sent a violation notice to Camp Grayling for storm water discharges of PFOS from Camp Grayling Cantonment to Lake Margrethe above Water Quality Value.
    • On November 21, 2022, a Camp Grayling RAB meeting was held. Updates on the drinking water sampling efforts around the Grayling area including Lake Margrethe were provided by ARNG and DHHS. An update on surface water and pore water sampling was given by EGLE. An update on the remedial investigation field work at Cantonment was provided by ARNG.
       
    • On January 17, 2023, a Camp Grayling RAB meeting was held to discuss updates pertaining to the Camp Grayling investigations.
    • On April 10, 2023, EGLE finalized the Camp Grayling, Lake Margrethe PFAS Groundwater Monitoring Report 2019 through 2022.
    • On April 10, 2023, EGLE finalized the Lake Margrethe Surface Water and Pore Water PFAS Investigation Report. 
    • On May 16, 2023, a Camp Grayling RAB meeting was held to provide updates on the Camp Grayling investigations. The day included a visit from Office of Secretary of Defense, Environment and Energy Resilience staff, to conduct interviews with regulators and RAB members for the Environmental Cleanup Communication and Outreach Initiative. 
    • On July 8, 2023, EGLE staff presented to the Lake Margrethe Property Owners association to provide updates on PFAS in the Lake Margrethe area. 
    • On August 3, 2023, EGLE provided comment on the ARNG Draft Community Involvement Plan – Camp Grayling, MI. 
    • On August 10, 2023, EGLE received the ARNG Draft Remedial Investigation Mobilization 2 workplan from ARNG. EGLE provided comment on August 17. Investigation is scheduled to start in September 2023.
    • On May 15, 2024, a Town Hall was held to discuss investigation updates, ARNG commitment to municipal water extensions, and an ARNG non-time critical removal action to reduce PFAS discharge from two stormwater pipes to Lake Margrethe. 
    • On June 14, 2024, EGLE provided comments on the non-time critical removal action engineering design to reduce PFAS discharge from two stormwater pipes to Lake Margrethe. Comments will be addressed by ARNG prior to implementation.
    • On July 15, 2025, EGLE received the Draft Final Field Planning Request for Lake Margrethe sampling from ARNG for comment.
    • On August 4, 2025, EGLE sent the ARNG a request to perform an Interim Remedial Action at Cantonment to prevent PFAS on-base from continuing to migrate to Lake Margrethe.
    • On August 13, 2025, EGLE provided ARNG with comments on the Draft Final Field Planning Request for Lake Margrethe sampling.
    • On August 27, 2025, EGLE received a response to EGLE comments from ARNG on the Draft Final Field Planning Request for Lake Margrethe sampling. 
    • On September 5, 2025, EGLE provided ARNG with a comment backcheck on the Draft Final Field Planning Request for Lake Margrethe sampling.
    • On September 15, 2025, EGLE provided ARNG with a letter certifying EGLE review of the Draft Final Field Planning Request for Lake Margrethe sampling.
    • On September 18, 2025, EGLE completed fieldwork observation of ARNG Lake Margrethe sampling.
    • On September 22, 2025, the ARNG sent a response to EGLE's request to perform an Interim Remedial Action at Cantonment to prevent PFAS on-base from continuing to migrate to Lake Margrethe.
    • On September 26, 2025, EGLE and ARNG participated in a comment resolution meeting for the Draft Final Field Planning Request for Lake Margrethe sampling.
    • On October 2 and 6, 2025 EGLE completed fieldwork observation of ARNG Lake Margrethe sampling.
    • On October 29, 2025, EGLE sent a response to the ARNG reiterating the request to perform an Interim Remedial Action at Cantonment.
    • On January 13, 2026, the ARNG presented the surface water, sediment, and porewater results from Lake Margrethe sampling at the Grayling RAB meeting.
    • On February 13, 2026, EGLE received the Cantonment Risk Assessment Workplan from ARNG for review.
    • On February 27, 2026, ARNG provided EGLE with the Draft Final NTCRA After Action Report and Cantonment Data Summary Report for review.
    • On March 16, 2026, EGLE provided ARNG with comments on the Cantonment Risk Assessment Workplan.