Plainfield Township's Municipal Water System
Updated: August 25, 2020
Plainfield Township's Municipal Water System is a water supply that has had detections of PFAS below the United States Environmental Protection Agency (USEPA) Lifetime Health Advisory (LHA) level of 70 parts per trillion (ppt) of PFOS and PFOA.
Plainfield Township is currently conducting a pilot study funded by a $750,000 grant through the Michigan Department of Environment, Great Lakes, and Energy (EGLE). For more information, Plainfield Township maintains a webpage specifically to update residents on the status of the pilot study.
- On June 28, 2013, drinking water samples were taken as required by the USEPA under Round 3 of the Unregulated Contaminant Monitoring Rule (UCMR3) (for more details on the UCMR program, visit the USEPA’s website). PFOS was detected in the drinking water sample at 50 ppt. At the time, the USEPA had a short-term provisional health advisory of 200 ppt PFOS; the 70 ppt LHA of 70 ppt PFOS+PFOA was not published until May 2016.
- On September 16, 2013, a second drinking water sample was taken as part of USEPA’s UCMR3. PFOS was detected in the drinking water sample at 60 ppt.
- October 2015: This date marks the last time Plainfield Township’s Versluis wells pumped water to the treatment plant, as future sampling of individual wells in March 2016 indicated high levels of PFAS. (The Versluis wells are only used for seasonal support during the summer; once they stopped running for summer 2015, they were not brought back online for summer 2016 and beyond).
- On March 15, 2016, anticipating the USEPA’s lowering of the provisional Health Action Level to 70 ppt in 2016, Plainfield Township conducted their own sampling of individual wells in Versluis Park. The results from this sampling indicate a significant source of PFAS in the area. The Township immediately determines the Versluis well field will not be used to meet peak summer demands, as it has done in the past.
- As of January 2019, the township continues to search for a replacement water source that is free of PFAS compounds.
- May 10, 2016: EGLE Superfund staff are alerted by the Kent County Health Department that PFAS was detected in the Plainfield Township Versluis wellfield through data collected during USEPA’s UCMR3 testing and the testing the Township did on their own. The Versluis wellfield is just north of the site and in the path of the groundwater flow. The wells still have not been used since October 2015.
- Up until June of 2018, Plainfield Township conducted quarterly testing at the water plant, to ensure stable levels and has recently sampled all the remaining wells individually. Sample results average 8.1 ppt at the water plant. Since then weekly testing at multiple locations has been conducted under the ongoing pilot study.
- In December 2017, funding was requested from EGLE to conduct a pilot study for PFAS removal in the Plainfield Township Municipal Supply using granular activated carbon (GAC) in the existing water filtration plant.
- In May 2018, the $750,000 grant was awarded to Plainfield Township by EGLE to conduct a pilot study for PFAS removal by retrofitting the existing filters with GAC media.
- On May 30, 2018, the Plainfield Township Municipal Supply was tested as part of EGLE’s statewide initiative to test all public water supplies and schools with their own wells.
- On July 31, 2018, the city was informed of the results of the sampling. The sample contained 8 ppt PFOS+PFOA and 22 ppt Total Tested PFAS. Results from this testing are available on EGLE’s public water supply statewide sampling initiative page.
- On July 10, 2018, installation of the GAC system in the treatment plant began. Three of the five filters for the Plainfield Township Municipal Supply pilot study have GAC installed, producing water that is non-detect for PFAS. The filters are reducing other contaminants as well such as disinfection byproducts. The last two filters will need to wait until summer peak demands wane.
- On October 11, 2018, the final two filters for the GAC pilot study at the Plainfield Township Municipal Supply are brought online. Test results indicate the larger size GAC media adsorbs the long-chain PFAS compounds entirely, but only a portion of some of the short-chain compounds. Conversely, the smaller size GAC media tends to remove all analytes to non-detect.
- EGLE is currently investigating potential sources of the PFAS contamination.
- The township is conducting preliminary engineering work to extend water service to customers affected by the Wolverine Worldwide contamination in Belmont.
- The Township is actively exploring potential new sources of groundwater to replace the Versluis well field.
- On December 31, 2019, the township finalized the report from the pilot study; read the full report: Water Treatment Plant Final Report, Plainfield GAC Pilot Project, GAC2018. The pilot study involves collection and analysis of many samples for PFAS, using two different analytical techniques. Following is a summary of some of those samples. It shows the effectiveness of the GAC filters, yet some PFAS remains in the treated water due to some filters operating without GAC. The Township has applied for permits to install GAC in the remaining filters (outside the scope of the pilot study). The report details the process used to implement the study and showed that within about 10 months, the city designed the study and improvements needed within their water treatment system, obtained the necessary permits, constructed the improvements and optimized their water plant to achieve treatment objectives, all while continuing to operate a fully functional treatment plant.