Thompson Lake is a highlight of Thompson County Park. But for the last few years, stormwater carried pollutants into the lake. Studies of the sediment in Thompson Lake identified contamination with chemicals from now-banned asphalt driveway sealant products, chloride (from road salt) and petroleum products. The sediments exceeded state requirements for some chemicals and may have acute and chronic impacts to humans and sediment-dwelling organisms.

Dakota County led a project to clean up the lake, so it will be a better place to fish and explore other recreational activities, like canoeing. The $2 million project was funded by the City of West St. Paul, the Lower Mississippi River Watershed Management Organization and Dakota County. The County put $1.3 million into removing contaminated sediments and investing in the lake’s future protection with a stormwater management project that will clean water before it enters the lake.

The project started in October 2018 and is scheduled to be complete in 2020.

For more information, see the Thompson Lake Restoration Story Map.