The Minnesota Pollution Control Agency announced on March 18 that nearly every closed landfill that it monitors has leaked per- and polyfluoroalkyl substances (PFAS) into groundwater.
Of the currently 110 closed landfills in the MPCA program —
- PFAS have been tested for at 101 of the landfills and detected at 98 of them
- At 59 landfills, PFAS detections exceeded the Minnesota Department of Health (MDH) drinking water guidance values
- Another 15 were linked to contaminations of levels 15 times above the safety limit; in one extreme case, involving the Gofer Landfill outside of Fairmont, PFAS were found in groundwater sources at concentrations 1300 times greater than the limit.
The MPCA has conducted a study showing that PFAS were present in the contact water at food waste and yard waste composting facilities. It is working with landfills that use spray irrigation as a method to treat and dispose of their leachate.
In the meantime, the MPCA is not allowing any solid waste facilities to start new spray irrigation application areas unless the leachate is sampled for PFAS and the resulting levels are below 1/4th of the state’s health-based values (set by MDH). The MPCA is also currently working with landfills on potential pretreatment of leachate to bring PFAS concentrations down to acceptable levels.
The MPCA is also seeking permission from the Minnesota Legislature to tap into the special fund backed mostly by Minnesota taxpayers to tend to the landfills in question. One official said the agency doesn’t have an estimate on the cost to remediate the landfills.
NGWA has long been an industry leader in providing PFAS research, education, and resources to the public and scientific communities. In 2017, NGWA published Groundwater and PFAS: State of Knowledge and Practice, which was one of the first PFAS guidance documents to be released. It can be found at NGWA.org/PFAS, which is a complete resource center about the groundwater contaminants featuring a FAQs document, a top-10 facts sheet, a homeowner checklist, and more.
As in previous years, NGWA is once again hosting an event on the topic — the Fate of PFAS: From Groundwater to Tap Water virtual conference will take place June 22-23.