Mining company Doe Run Resources Corp. and the Missouri Department of Natural Resources’ (MDNR) Division of State Parks have agreed to remove lead contamination at St. Joe State Park, including off-road vehicle riding areas and a former lead milling location now preserved as a museum, as well as an adjacent section of the Shaw Branch floodplain in St. Francois County, Mo.
The terms of the Environmental Protection Agency’s agreement with Doe Run and MDNR are outlined in an administrative settlement agreement and order on consent, filed in Kansas City, Kan. Under the order, Doe Run and MDNR must submit a draft work plan to the EPA, outlining intended steps to complete the removal action, within 60 days.
The EPA estimates that the removal action will cost about $7 million and take approximately 18 months to complete.
The order focuses on a 1,240-acre portion of the 8,238-acre St. Joe State Park, Missouri’s third-largest state park, located near the city of Park Hills. The site is known to the EPA as the Federal Tailings Pile Superfund Site, a sub-site of Big River Mine Tailings Superfund Site, which is on the Agency’s National Priorities List for cleanup of hazardous lead.
Superfund is the EPA’s program to clean up the country’s most hazardous waste sites. Sites in the program are eligible for federal funding.
St. Joe Minerals Corp., which changed its name to Doe Run Resources Corp. in 1994, conducted lead mining and milling operations in the vicinity from approximately 1923 to 1972. The company gave the park portion of the site as a gift to the State of Missouri in 1976.
Soils at the site are extensively contaminated with toxic lead and lead compounds from mining wastes that accumulated over several decades, the EPA said. Soil samples collected during recent inspections of the site have been found to contain up to 20,000 parts per million of lead.
Additionally, high levels of lead have been found in sediment, surface water, and aquatic life in a watercourse adjacent to the site. Actions to address lead contamination in the Shaw Branch floodplain in the EPA’s order include:
- All off-road vehicle trails that are contaminated with 600 mg/kg or more of lead will be covered with a minimum of 12 inches of clean soil, rock, or a mixture of both.
- Steep slopes will be regraded and stabilized with rock to prevent erosion. Vegetation will be established or augmented to reduce exposure to the public and minimize erosion.
- Sediment and surface water will be addressed by removing creekside lead tailings deposits, constructing stormwater retention structures to help reduce the movement of sediment, regrading to stabilize steep slopes, and improving drainage channels that cross the site.
- Post-removal controls, including administrative controls to prevent public access to vegetated areas, and ongoing monitoring to ensure the remedy remains protective, must be implemented.
Nearly all of the cleanup costs will be covered by funds from a special account that was established in 2009 as part of the $1.79 billion bankruptcy settlement involving former smelting and mining firm Asarco. A $7.7 million special account was specifically set aside for cleanup of the Federal Tailings Pile Superfund Site, which includes St. Joe State Park.
As a result of the Asarco settlement, the largest environmental bankruptcy case in U.S. history, special accounts were established to pay for past and future cleanup costs incurred by federal and state agencies at more than 80 Superfund sites contaminated by mining operations in Missouri and 18 other states.