PARK HILLS — For years, a massive pile of chat, fragments of rock from mining waste, has stood above the landscape in the eastern Missouri town of Park Hills. Now, Doe Run Co. is lowering the pile as part of a remediation project.
In fact, piles and mine tailing fields have already been addressed in neighboring communities - Bone Terre, Desloge, Leadwood and the Elvins/Rivermines areas.
The areas were designated as Superfund sites by the Environmental Protection Agency. As owners of the chat piles, Doe Run is responsible for cleanup and prevention of future contamination of surrounding property.
The effort began July 1 with a crew of 20 performing the work. Over a one-year period, the company plans to move more than 1 million yards of chat, drill through the pile to identify the nature of the land underneath and come up with a plan to finish the project, said John Carter, mining properties manager for Doe Run.
"What we have found is there's some very fine unstable portions under the big chat pile," Carter said. "We think that the slime generated in the old chat pile just south is under part of the big pile. What we do on the slopes depends on how thick the slime is."
Carter said crews have removed about 45 feet of chat from the top of the Park Hills pile. The drilling will show whether they have to lower the pile more. Even if the pile is fine at its current height, material from the top will be pulled down to stabilize the slopes and construct a reinforcement berm around the pile.
The top and sides will be covered with rock. The company did the same thing at a chat pile in Bonne Terre.
Eventually, the company will cover a sewer line with clean soil along the Flat River. The city hopes to use that area as a walking trail, said Norm Lucas, Park Hills economic developer.
While Doe Run owns the chat pile, the property it sits on is owned by several parties, including the city of Park Hills.
The pile looms behind the home of Greg and Regina Burcham, who have lived there 19 years.
"We've never had any concern," Regina Burcham said of the mountain of chat rising behind her backyard. "We played on that thing when we were little. The dust in the house is the only problem we have."
That dust is part of the reason the EPA wants something done to stabilize the chat pile. The agency is concerned about possible health risks — especially to children — from the lead-contaminated material.
Lead in its natural form is not considered a health hazard because it is not soluble in plain water. However, once lead is smelted or oxidized, it can be readily taken up by biological tissues. That poses a health risk to humans, especially children.
Chat is the leftover material from the older version of lead processing, when rock was crushed to separate out the lead. The remaining rock still contains some lead. This version of processing produced particles that were similar to beach sand.
Like the Burchams, James Jennings is not worried about the chat pile in his back yard.
"I've lived here 50 years, and I'm 75 and still chopping wood," he said. "My mom lived up the street, and she lived to be 97. My wife's mother lived across the street, and she was almost 100 when she died."