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BASF Corporation - Inmont Division (Wyoming, Kent County)
Please contact the Site Lead for the most up-to-date status of this site.
The BASF Corporation (BASF) facility has been industrial since the late-1800s, with uses including the manufacturing/application of furniture finishes and paint. BASF stopped operations at the plant in 1987 to begin manufacturing automotive paint and container coatings; these operations stopped in 1999. An environmental investigation was conducted at the site in 1988 after it was discovered there were leaks from piping and storage tanks. A groundwater pump-and-treat system was installed later in 1993 to clean up many contaminants other than PFAS in the groundwater at the site. The treatment system discharges the treated water into the city of Wyoming's sanitary sewer system for final treatment and eventual release to the Grand River.
On May 7-9, 2018, the city of Wyoming conducted an initial round of testing of wastewater coming into their water treatment plant from locations that held Industrial Pretreatment Permits, such as BASF. A second round of wastewater samples was collected from the facility on August 14, 2018. Results from these sampling events showed elevated PFAS levels in the wastewater coming from BASF. Given the facility's history and the fact that the only wastewater generated at the BASF facility was derived from groundwater extraction wells installed on-site, EGLE requested BASF develop a workplan to assess the presence of PFAS in the groundwater. BASF presented this workplan to EGLE on April 3, 2019, which included groundwater treatment system effluent sample results, which confirmed PFAS in the wastewater and most likely in the groundwater as well.
The groundwater treatment system gathers groundwater from a total of 14 environmental remediation extraction wells from across the site including 11 from the former plant area and 3 from a former storage tank area. The site is in an industrial area immediately adjacent to Plaster Creek. The Grand River is about 1.2 miles downgradient from the site. Groundwater flow is to the north-northeast, paralleling and discharging to Plaster Creek. However, the groundwater treatment system has been working since 1993, so groundwater flow is generally towards the extraction wells on-site. The extent of PFAS contamination has not yet been determined. BASF is also working to engineer a change from a biological treatment system--which treats another contaminant--to a granular activated carbon (GAC) system which will treat both the other contaminant and PFAS.
Content posted January 2021.
Surrounding residents/businesses are on municipal water from the City of Wyoming. There are no known drinking water wells in the current investigation area. EGLE has tested all municipal water supplies for PFAS. View the results for the city of Wyoming.
BASF will continue to investigate PFAS at the facility in accordance with Michigan’s environmental law. One additional groundwater extraction/pumping well will be installed to capture groundwater in the eastern portion of the site and to assure that PFAS impacted groundwater is not migrating into Plaster Creek. BASF continues to wait for supplies and materials (such as carbon filters) to upgrade the groundwater treatment system to remove PFAS chemicals and other contaminants in the groundwater pumped from the facility prior to discharge into the municipal sanitary sewer system. The City of Wyoming and EGLE are overseeing these efforts. This work is scheduled for first quarter of 2021.
- On May 21, 2018, BASF’s consultant collected a single sample of the groundwater treatment system’s effluent from the sample spigot to test for PFAS.
- On April 3, 2019, EGLE received the results from the May 21, 2018 groundwater treatment system effluent sampling from BASF in a workplan from the facility. The results were 517 ppt PFOS and 30.6 ppt PFOA.
- On November 7-9, 2019, groundwater samples were collected from monitoring wells at the facility.
- On January 8, 2020, EGLE was provided a report summarizing the data collected in November 2019. Sample data is reflected on the sampling chart.
- On February 7, 2020, BASF submitted a First Quarter 2020 sampling work plan which included additional groundwater monitoring wells and EGLE provided feedback on the work plan.
- On June 10, 2020, EGLE was provided the 2019 groundwater treatment system performance monitoring report.
- On June 22, 2020, EGLE was provided with a summary of the results for the March 2020 groundwater sampling event; 21 wells were sampled and analyzed for PFAS. Results are reflected on the sampling chart.
- On June 22, 2020, EGLE participated in a conference call meeting to discuss the findings of the spring sampling event and next steps.
- Between July 20 and July 21, 2020, BASF conducted a round of quarterly groundwater sampling at the facility.
- On September 9, 2020, EGLE was provided with the results of the July 20, 2020 groundwater sampling event. The highest PFOS sample result was 13,400 ppt and the highest PFOA was 805 ppt.
On September 28, 2020, EGLE participated in a call with BASF’s consultant to discuss the findings of the July sampling event, plans for the installation of additional monitoring wells, plans to install an additional extraction well to capture groundwater that may be discharging to Plaster Creek in the vicinity of MW-8, and discuss the status of upgrades to the groundwater treatment system to remove PFAS.
Historical Sampling Chart: Data is reflective of criteria prior to August 3, 2020, PFOS and PFOA Only
This chart reflects data received prior to August 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
May 8 - November 2019 4 4 0 1 3 Groundwater Influent and Monitoring Wells September 2019 - March 2019 38 38 0 11 27 Cumulative
42 42 0 12 30
*Groundwater results are compared to EGLE Part 201 Criteria of 70 ppt PFOS+PFOA.
Sampling Results Summary
This table was updated to include all seven PFAS criteria effective December 21, 2020.
Type of Sample
Date Sampled (or Range)
Numberof Sample Results Received
Number of Samples above Criteria*
Groundwater Monitoring Wells
September 2019 - March 2021 109 89
*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).
- On August 3, 2020, new Part 201 Criteria went into effect. Historical sampling data compared to Part 201 Criteria >70 is captured in the historical timeline below.
- Other PFAS analytes were detected in samples. There are no federal or state standards for these analytes.
- Samples collected in September and November 2019 were only analyzed for PFOA and PFAS.