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K.I. Sawyer Air Force Base (Gwinn, Marquette County)

K.I. Sawyer Air Force Base (Gwinn, Marquette County)

Disclaimer: Web content may not be routinely updated on this page.

Please contact the Site Lead for the most up-to-date status of this site.

EGLE site lead

Kenneth Heitkamp, HeitkampK@Michigan.gov or 517-930-5218.

Background

K.I. Sawyer Air Force Base (KISAFB) is a former United States Air Force (USAF) base located near Gwinn. In 1994 after almost 40 years of operation, the KISAFB base closed under the United States federal government Base Realignment and Closure Act (BRAC). In 1999 Marquette County Airport, Sawyer International, occupying portions of the former base officially opened. Under BRAC the USAF is responsible for investigating and if necessary, addressing any environmental contamination caused by the Air Force while operating KIASB. For the past twenty years the USAF has been investigating and resolving environmental issues at the former base. Per- and polyfluoroalkyl substances (PFAS) are a group of over 5000 man-made chemicals that includes PFOA and PFOS. Firefighting foams used by the USAF contained PFOS and PFOA as active ingredients. In 2015 the Air Force identified 15 potential PFAS sites at the former KISAFB. In 2016 USAF conducted limited investigations of each site and detected PFAS at 13 of the 15 sites. USAF detected the highest concentration of PFAS at a former fire training area (FT007). The investigation and analysis of these PFAS sites by the Air Force is ongoing and will continue into the foreseeable future.

Content posted March 2026.

Aerial View of K.I. Sawyer Air Force Base, Gwinn, Marquette County

Site map

See an aerial view of the location of the site.

Expand the map

Drinking water

  • MDHHS is offering drinking water well retesting to residents near K.I. Sawyer AFB whose wells were previously tested for PFAS or who were offered drinking water filters, or both. There is no charge for the testing. MDHHS has contacted these residents by letter and by phone to schedule water collection appointments. Seasonal residents who are away for the winter can schedule an appointment later. The goal of repeat testing is to determine if PFAS is in residential wells; if so, the amount of PFAS; and whether the amount is increasing, decreasing, or remaining the same over time. MDHHS will be regularly retesting these drinking water wells in coordination and District Health Department.
  • Residents who have questions about this PFAS testing effort or who would like to schedule an appointment can call the MDHHS Environmental Health Hotline at 800-648-6942.
  • Four municipal wells supplying water to the K.I. Sawyer Community have been monitored for PFAS since 2018. Currently, the State of Michigan requires PFAS sampling of these wells once a year.
     

Anticipated activities

  • Investigation mid-April to Fall 2026 – AFCEC will continue the RI of all PFAS sites at KISAFB.
  • Every month, Air Force hosts a Base Realignment and Closure (BRAC) Cleanup Team (BCT) meeting with EGLE and MDHHS via teleconference.
  • In 2026, AFCEC plans additional drinking water well sampling with updated laboratory methods. 
  • Air Force K.I. Sawyer Restoration Advisory Board (RAB) and Public Meetings are both scheduled annually. For more information, visit the AFCEC RAB website. Previous meeting materials and recordings can also be found at this site.  Public meetings are posted on the MPART public meeting calendar as they are scheduled. 

Historical timeline

    • In April 2014, the former K.I. Sawyer Air Force Base site first came to the attention of the Michigan Department of Environment, Great Lakes, and Energy (EGLE) when the USAF’s contractor met with EGLE to conduct a record search to begin the USAF’s investigation into the base.
    • In 2014-2015, the initial investigation (informally called “Phase I” by EGLE) was conducted by the USAF and included two fire training areas in the investigation area.
    • The USAF sampled four municipal wells in 2015; PFOS was detected in one well at 1.36 ppt (not detected in a field duplicate from that well); all others were non-detect. 
    • From 2015-2016, hundreds of soil samples were taken, along with samples from the four on-base municipal water supply wells, groundwater, surface water, and at the Wastewater Treatment Plant (WWTP).
    • In 2016, Marquette County sampled the four municipal wells; all were non-detect.
    • In 2016-2017, the “Phase II” investigation by the USAF occurred and included other suspected locations of PFAS use, including three plane crash sites, fire suppression systems in a few buildings, storm water infiltration basins, two streams, three lakes, the WWTP, two landfills, and undeveloped areas where WWTP sludges were land-applied.
    • In 2017, the USAF conducted sampling of surface water, sediment, the WWTP, and two residential wells east of the base. One of two residential wells had PFAS above the USEPA's Lifetime Health Advisory Level of 70 parts per trillion (ppt) PFOA and PFOS individually or combined; the other was non-detect. Bottled water was provided immediately by the USAF upon receipt of the first residential well samples, and follow-up samples collected from both residential wells had essentially identical results.
    • In June 2018, the USAF installed a whole-house treatment system in a residence, and the treatment system is being operated by the USAF for the resident. Initial samples of the treated water were non-detect for all PFAS compounds (and they were consistent with concentrations in the well sample). The first routine quarterly samples of the system and the well were collected in early September 2018; (verbal) results show consistent contaminant levels in the well sample, and non-detect for the treated water.
    • In November 2018, the USAF began a follow-up investigation of the extent of PFAS migration off-base (“Phase IV”).  Six monitor wells (MWs) were installed, with an additional deeper MW at one of those locations planned once all recent sample data are available (note: the results have to date only been reported verbally). Additional locations were to be determined in 2019 based on all the new sample results, but the lack of detections caused the USAF to cancel the rest of the planned work and re-evaluate the plan.
    • In December 2018, the USAF sampled the affected residential well; results were consistent with all previous samples.
    • In December 2018, USAF focused its efforts on FT007. The USAF investigation or Site Inspection (SI) of FT007 consists of 3 Stages.  Stage 1 of the SI focused on evaluating geology, groundwater flow, and the sampling of shallow groundwater around FT007 for PFAS. The objective of Stage 2 was to determine if PFAS was present in deeper groundwater. USAF completed Stage 1 December 2018 and Stage 2 in August 2019. The results from Stage 1 and Stage 2 SI indicate:
      • Groundwater flows in an easterly direction from FT007
      • A subsurface clay layer east of FT007 divides the groundwater into an upper and a lower aquifer
      • PFAS contamination in the vicinity of FT007 is in the upper aquifer
      • PFAS contamination downgradient of FT007 appears to be primarily in the lower aquifer
    • In December 2018, EGLE approved the final Site Inspection (SI) Report (“Phases I & II” work done on- and off-base from 2015 through 2017).
    • In December 2018, the USAF submitted their Final Supplemental Site Inspection (SSI) Report (“Phase III” 
    • In January 2019, EGLE approved the Final SSI Report (“Phase III” work).
    • In January 2019, EGLE provided an updated map for this site to use on the MPART webpage for the public.
    • In March 2019, EGLE provided comments on the draft Site Investigation Workplan ("Phase IV") Revision 1 to the USAF.
    • On March 14, 2019, the USAF's contractor sampled the well and the treatment system at the one affected residence. Results were consistent with all previous samples (with no detections of PFAS after treatment).
    • On April 30, 2019, EGLE staff met with the USAF and contractors in Knoxville to finalize presentations to the AFCEC Administration for 2019 projects funding requests. 
    • On May 22, 2019, the USAF hosted an evening Public Information session. EGLE staff did not participate due to unexpected illness, however, MDHHS staff were in attendance, gave a presentation, and answered residents' questions. 
    • From July 17 – 20, 2019, the USAF and the USAF’s contractor sampled 26 residences downgradient of the single affected residence.  A total of 27 samples (plus 3 field duplicates) were collected; two residences have treatment systems for high iron, and so samples were collected at each from before and after the treatment system.  Samples also were collected from the one affected residence and the treatment system.
    • From July 16 – 24, 2019, the USAF’s contractor installed a deep MW adjacent to a contaminated water table MW, after vertically profiling the aquifer (8 samples collected).
    • In late July 2019, the USAF’s contractor sampled the well and the treatment system at the one affected residence.  Verbal results are consistent with all previous samples.
    • In early August 2019, the USAF’s contractor installed two additional shallow MWs in the residential well area, and two staff gauges in Silver Lead Creek to further refine the Conceptual Site Model.
    • In late September 2019, EGLE met with the USAF and their contractor to review/approve locations for approximately 18 new MWs in the vicinity of the affected residential well, proposed to complete the site characterization (the exact number may change based on initial results).
    • On October 16, 2019 the annual meeting of the Restoration Advisory Board (RAB) was held. This was not an EGLE or State hosted event.  Ten interested citizens attended.
    • On November 12, 2019. EGLE approved a USAF work plan for modifications to the residential well treatment system.
    • On December 5, 2019 EGLE staff presented “Michigan Taking Action on PFAS” to the Michigan Tribal Environmental Group in Baraga.
    • On December 11, 2019, EGLE staff presented a status update on UP PFAS sites to the four Upper Peninsula Tribes.
    • In January 2020, EGLE staff met with USAF and their contractors to review their plans for 2020 field work, review/accept modifications to the residential well treatment system sampling schedule, and to transition EGLE project management due to the Site Lead’s retirement in February.
    • October 2020 USAF completed Stage 3 of the SI for FT007.  The objective of Stage 3 was to gain a better understanding of the subsurface geology, groundwater flow direction and the distribution and movement of PFAS in the groundwater.  The Air Force conducted Stage 3 in two mobilizations.  During Mob 1 the Air Force completed two exploratory borings along the eastern boundary of KIASB downgradient of FT007.  In one boring the Air Force detected PFAS in groundwater between 120 and 180 feet below the surface.  In Mob 2 the Air Force completed 3 exploratory borings, installed, and sampled 3 temporary monitoring wells and measured groundwater elevations in 78 exiting wells and the three temporary monitoring wells.
    • USAF identified and sampled 28 residential wells within a 4-mile radius downgradient from FT007.  Of the 28 wells sampled, one well was determined to have PFAS at levels above what is considered safe to drink.  USAF installed a treatment system for this well and continues to test the drinking water.  June 2020, USAF sampled the water after treatment.  Lab results indicate there are no PFAS in the drinking water.
       
    • In 2021, Air Force hosted a monthly Base Realignment and Closure (BRAC) Cleanup Team (BCT) meeting with EGLE via teleconference. 
    • In June 2021, AFCEC submitted the Final PFOS and PFOA Expanded Site Inspection Report.
    • In July 2021, AFCEC submitted the Final PFOS and PFOA Comprehensive Groundwater Sampling Technical Memorandum.
    • In 2022, Air Force hosted a monthly Base Realignment and Closure (BRAC) Cleanup Team (BCT) meeting with EGLE via teleconference. 
    • In June 2022, AFCEC submitted the Final Quality Program Plan for Remedial Investigation of Per- and Polyfluoroalkyl Substances
    • In October 2022, AFCEC submitted the Final Remedial Injection Work Plan for Sites FT007 and SS017
    • In 2023, Air Force hosted a monthly Base Realignment and Closure (BRAC) Cleanup Team (BCT) meeting with EGLE via teleconference.
    • In June 2023, AFCEC submitted the Final Remedial Injection Completion Report for Sites FT007 and Site SS017
    • On October 18, 2023, Air Force hosted a Restoration Advisory Board (RAB) meeting at K.I. Sawyer AFB. Check the Air Force RAB Page for RAB materials.
    • From January 30 – February 1, 2024, a Technical Meeting with AFCEC was held to discuss PFAS sampling in sediment, surface water, groundwater and soil, as well as ecological and human health risk assessments
    • In 2024, Air Force hosted a monthly Base Realignment and Closure (BRAC) Cleanup Team (BCT) meeting with EGLE and MDHHS via teleconference. 
    • In April 2024, AFCEC submitted the Addendum 02 to the Final Quality Program Plan for Remedial Investigation of Per- and Polyfluoroalkyl Substances
    • On June 3, 2024, a Systematic Project Planning session with AFCEC was held to plan PFAS sampling locations and discuss Quality Program Plan for Remedial Investigation of Per- and Polyfluoroalkyl Substances
    • On July 24, 2024, Air Force hosted a Public Meeting at K.I. Sawyer AFB. Discussions included recent sampling results and future sampling plans. A Technical Planning Process meeting was held prior to the meeting between AFCEC and EGLE.
    • On August 26, 2024, a Systematic Project Planning session with AFCEC was held to discuss Quality Program Plan Addendums and field work updates
    • On October 17, 2024, Air Force hosted a Restoration Advisory Board (RAB) meeting at K.I. Sawyer AFB. Check the Air Force RAB Page for RAB materials
    • In 2025, Air Force hosted a monthly Base Realignment and Closure (BRAC) Cleanup Team (BCT) meeting with EGLE and MDHHS via teleconference. 
    • In 2025, due to AFCEC contracts/funding issues, the PFAS RI field work was delayed and resumed in 2026.
    • In February 2025, EGLE provided comment on the PFAS Risk Assessment Work Plans for Ecological and Human Health. In February 2025, EGLE provided comment to AFCEC regarding the Quality Assurance Project Plan Addendum 03 Revision 1 – including PFAS sampling of surface water, sediment and groundwater.
    • On October 9, 2025, Air Force was scheduled to host a Restoration Advisory Board (RAB) meeting at K.I. Sawyer AFB, however due to the federal government budget shutdown, the RAB Meeting was postponed. The new RAB date will be held in Spring 2026, exact dates are TBD. Check the Air Force RAB Page for RAB materials.
    • Air Force hosted the monthly Base Realignment and Closure (BRAC) Cleanup Team (BCT) meeting with EGLE and MDHHS via teleconference. 
    • January 2026 - Technical Meeting with AFCEC to discuss Quality Assurance Project Plan Addendum 4 for PFAS sampling.

    Historical Sampling Chart: data is reflective of criteria prior to 8/3/2020:
    PFOS + PFOA Only

    This chart reflects data received prior to 8/3/2020.

    Type of Sample

    Date Sampled (or Range)

    Number of Samples

    Number of Results Received

    		 Number of Non-Detects  Number Between Non-detect and Standard*  Number Greater Than or Equal to Standard 

    Drinking Water (Residential Wells)

    		 2017 - June 2020 42 16 5 0 11
    Groundwater 2015 - June 2020 96 96 38 24 34
    Surface Water 2015 - 2018 22 22 3 6 13
    WWTP Effluent 2016 - 2017 2 2 0 0 2
    Cumulative 162 136 46 30 60

    *Groundwater results are compared to EGLE Part 201 Criteria of 70 ppt PFOS+PFOA.
    *Residential well results are compared to the EPA Lifetime Health Advisory Level of 70 ppt PFOS+PFOA.
    *Surface water results are compared to Rule 57 surface water quality values of 12 ppt PFOS and 12,000 ppt PFOA

    Related Sampling Notes

    • Surface water and groundwater samples reflect both on-base and off-base activities.
    • Soil, sediment, sanitary sewer influent, and groundwater treatment system effluent samples have been taken by the USAF at this site.