The Environmental Protection Agency plans to test 256 Jefferson County residential properties amid concerns that lead in the Big River is contaminating soil.
The St. Louis Post-Dispatch reports that testing is expected to be completed by midsummer. Recent studies and samples indicated widespread lead contamination in the flood plain that extends from Leadwood in St. Francois County to the confluence with the Meramec River near Eureka.
While testing will be done at 256 properties, nearly 2,000 residentially zoned properties sit in the flood plain in Jefferson County.
The Southwest Jefferson County Mining Superfund site covers Jefferson County but excludes Herculaneum, home to the Doe Run lead smelter, which has its own Superfund site.
The contamination is linked to long-gone lead mining operations that date to the early 1800s. Historical records show more than 3 million pounds of lead were shipped out of the county per year by the mid-1800s, making it one of the largest lead-producing areas in the nation.
Lead concerns in the Big River also prompted the Missouri Department of Health and Human Services to issue a fish advisory, urging people not to eat carp, suckers, long-ear sunfish, green sunfish, bluegill, warmouth sunfish or rock bass caught in the Big River in St. Francois or Jefferson counties.