Fungi used to filter pollutants at Memorial Field

SANDPOINT -- Mushrooms are being used to capture hydrocarbons and other pollutants that would normally wind up in Lake Pend Oreille at the Memorial Field boat launch.

The demonstration project, which showcases a best management practice for keeping pollution out of the lake, replaces the hard-pack gravel shoulder next to the launch ramp with a series of descending basins designed to filter out pollutants before they enter the water.

"It basically was a gravel patch that had very little usefulness," said Gary Parker, program coordinator for Lake*A*Syst, which arms landowners with practical information on how they can take an active role in protecting local water quality.

Before the project was installed, stormwater swept over the gravel shoulder and into the lake. Stormwater would also hit the asphalt parking lot and wash into the water, leaving the distinctive rainbow sheen of hydrocarbons.

The demonstration project aims to route stormwater runoff through the basins. The top six basins are filled layers of wood chips inoculated with phoenix fir oyster mushrooms and the bottom three basins contain layers of pearl oyster mushrooms. The fungi have been shown to break down pollutants, according to Scott Daily, a certified permaculturist with Full Circle Design, which designed the project.

A grate will be installed perpendicularly on the launch ramp to catch stormwater and feed it to the basins.

The project has serendipitous origins.

"We were looking for a high-profile site," said Parker. "We wanted to show landowners what they could do on their property."

The same day Parker was looking for a site, Daily called Parker looking for a project.

The city of Sandpoint's Public Works and Parks & Recreation departments provided the site, while the Bonner Soil & Water Conservation District, Natural Resource Conservation Service, Tri-State Water Quality Council collaborated to implement the project.