Could Mushrooms Clean Up 'Forever Chemicals'? Merrimack Pilot Wins State Backing

Angela Graves, a lifelong Merrimack resident, has received preliminary backing from the New Hampshire Department of Environmental Services to run a small experimental trial using fungi to address PFAS contamination near the former Saint‑Gobain Performance Plastics site.

Frustrated by the slow pace of official remediation planning, Graves — now a field organizer with the League of Conservation Voters and a recent Plymouth State University graduate — designed a mycoremediation pilot focused on perfluorooctanoic acid (PFOA), one of the better-known per‑ and polyfluoroalkyl substances (PFAS).

What the pilot will do

The proposed study will establish a 10‑square‑foot plot on or near the former factory grounds and cultivate native fungi, including strains in the white‑rot group that laboratory research suggests can break some PFAS bonds. The team will sample soil for baseline PFOA levels, grow the fungi in place, then resample the soil after the fungi have established and produced fruiting bodies.

When mushrooms mature, researchers will harvest and test the fungal tissue to quantify how much PFOA the organisms have taken up. Harvested biomass would then be incinerated at temperatures sufficient to destroy PFAS compounds. By comparing pre‑ and post‑treatment soil concentrations and measuring contaminants in the mushrooms, the pilot aims to determine whether mycoremediation can produce a measurable reduction in surface PFOA levels.

Benefits and limitations

Graves and supporters describe the approach as relatively low cost and more natural than chemical treatments. As of Nov. 25 she requested roughly $7,000 from the state to cover baseline and follow‑up testing of soil and fungal tissue; final funding details were still pending.

Experts caution that biological remediation for PFAS remains under‑explored. Paula Mouser, a civil and environmental engineering professor at the University of New Hampshire, noted that even when organisms attack PFAS bonds, the process can produce intermediate chemicals rather than fully mineralize the compounds. Fungi usually colonize surface and shallow soils and may not reach deeper contamination, so mycoremediation is best suited to treating upper layers of soil.

Next steps and community impact

Graves has worked with the Department of Environmental Services on her proposal and hopes to begin propagation in the spring. It remains unclear whether the study may take place on former Saint‑Gobain property — the plant was demolished in July but the land is still owned by the company — so she plans to site the plot on adjacent private land if necessary.

Local officials have expressed support for the idea as a modest, practical step toward reducing the PFAS burden in Merrimack, easing community health concerns and the reliance on costly water filtration. “We’re looking to start at least something,” Graves said.