ST. LOUIS - A consent agreement announced Wednesday calls for spending $111 million to remove lead from about 4,100 residential properties in Missouri's "Old Lead Belt" region southwest of St. Louis.

The agreement is between Doe Run Co., a St. Louis-based mining company, the federal government and the state of Missouri. Sampling will be conducted on properties in St. Francois County, and contaminated soil will be dug up and removed. Work will begin this year and take up to 12 years to complete, Doe Run said.

The Old Lead Belt region was once one of the largest lead mining districts in the world. Lead hasn't been mined there for decades, but contamination has been cited in yards throughout St. Francois County, about 70 miles southwest of St. Louis.

Young children are especially vulnerable to lead poisoning, potentially causing behavioural disorders, learning disabilities, seizures and, in rare cases, death.

The Environmental Protection Agency said that in three zip codes compromising most of the cleanup area, between 9.3 per cent and 16.7 per cent of children had elevated blood lead levels. Nationally, about 2.5 per cent of children have elevated blood lead levels.

Lead was mined in parts of the Old Lead Belt for about 300 years through the early 1970s. What was leftover was waste from lead, cadmium and zinc that ended up in yards, parks, school properties, roads and streets.

"Timely action to clean up these contaminated areas is vital to the surrounding communities," Acting Assistant Attorney General Jeffrey H. Wood said in a statement.

The project will be funded with $31.5 million from the EPA Superfund program. It wasn't clear how much of the rest of the cost would be borne by Doe Run. A spokeswoman said the company may seek reimbursement from other "potentially responsible parties" such as other companies that formerly mined in the area, though many of those firms are no longer in existence.

Property owners will not pay any of the remediation cost, federal officials said.

"Doe Run is committed to assisting regulators to address non-naturally occurring sources of lead in residential soils where Doe Run had historic operations," Mark Yingling, Doe Run's vice-president for environment, health and safety, said in a statement.

The cleanup program is among several over the past several decades in St. Francois County.

News from © The Associated Press, 2018