The City of Ann Arbor, Michigan’s Compost Facility PFAS Fact Sheet — “Keeping Our Customers Informed About PFAS” — includes frequently asked questions about PFAS in compost. Ann Arbor offers residents curbside food scraps and yard trimmings collection service from April to December; yard trimmings can also be dropped off at the city’s composting facility. The fact sheet reports results of recent tests that the city conducted on Ann Arbor’s compost. “Results tested positive for low levels of 13 types of PFAS ranging from 0.040 parts per billion (ppb) to 17 ppb,” notes the city. “Soil samples are measured in ppb. The water in the ponds at the compost facility was also sampled and tested positive for 12 types of PFAS ranging from 0.44 parts per trillion (ppt) to 680 ppt.”
The fact sheet acknowledges that “research on PFAS in compost is extremely limited. … There is no scientifically approved method for how to test PFAS in soil, so while trace amounts were found there are no established health advisory guidelines for the city or residents to follow. What we do know is we want our customers to be informed of these results and actions we are taking to further reduce contamination.”