HERCULANEUM — More than 100 properties near the Doe Run Co.'s smelter have been recontaminated with dangerous levels of lead, a finding that comes less than a decade after regulators ordered the company to remove and replace polluted soil on the properties, the U.S. Environmental Protection Agency said Monday.

Tests of 372 properties within a mile of the lead smelter found 129 properties contained lead at levels beyond the EPA's allowable limit of 400 parts per million. Of those, 104 properties had already undergone soil EPA-ordered soil remediation within the last nine years.

"While Doe Run has taken some steps in recent years to reduce lead emissions, those efforts clearly fall short of what was necessary," William Rice, the EPA's acting regional administrator, said in a prepared statement. "The recontamination we are seeing in Herculaneum is unacceptable."

The agency also said it is considering a "range of enforcement actions" against the company, although no details were given.

Doe Run, however, played down the extensiveness of the problem, saying that just 29 properties were above the level of concern if the multiple results from each property were averaged. Nearly half of those were in the voluntary buyout zone around the plant, according to the company. Seven more properties have had no remediation done, so the results aren't new, according to the company. In a few cases, the company said, it appeared lead could have come from somewhere else.

According to Doe Run's math, "this leaves three properties outside the former purchase area with elevated levels from another source, including more recent airborne deposition."

Gary Hughes, Doe Run's general manager of the 117-year-old Herculaneum smelter, said the company met with neighbors last week to discuss the findings and will work with residents and the EPA to determine what must be done on each property.

"We want to make sure residents know we care about their families and their concerns, and we'll be keeping the lines of communication open as we work through the process with EPA," he said in a statement.

Larry O'Leary, who lives less than two miles from the smelter and is part of a citizens' advisory group that works on the issue, said he wasn't surprised to learn about the continued pollution but said he was surprised the rates of it were so high.

"There has to be some kind of consequence for continued contamination," he said. "Now what that is, I don't know."

The Doe Run smelter in Herculaneum is nation's last operating lead smelter. Lead is a neurotoxin that interrupts normal brain development and has been linked to behavioral problems in children. Adults can tolerate higher levels of lead than children can but can still can suffer from health problems.

Jim Kasten, the city administrator, said he believes Doe Run will step up to resolve the contamination problems.

"They've proven to be a good neighbor. I'm confident if there's a yard that needs remediation, they'll address that," he said.

"This is a small step backwards," Kasten said. "The people of Herculaneum will group together with the help of Doe Run and the agencies and work through this process and make things better."

This round of testing began in July, when the EPA ordered Doe Run to test gravel driveways and yard soils from all homes within one mile of the smelter. A contractor completed those tests last month, and the company recently notified property owners of the contamination levels found on their land.

In 2001, environmental regulators forced Doe Run to clean contaminated properties, an expensive process that included removing and replacing tons of polluted soil. In 2002, Doe Run agreed to offer voluntary buyouts to about 170 homeowners who owned property close to the smelter. Two years later, the Missouri Department of Natural Resources warned holdout property owners that their yards would likely be recontaminated with unsafe levels of lead within 10 years.

Doe Run built a truck wash in October 2003 to help reduce the spread of lead dust on public roads. But Kathleen Logan Smith, director of the Missouri Coalition for the Environment, said the trucks aren't washed adequately and that is the cause of much of the contamination.

"They don't do something very, very simple to keep people safe," she said, adding that no fines ever have been levied against Doe Run.