SCOTT AIR FORCE BASE — After 30 years as a dumping ground for household and industrial wastes, the 36-acre landfill on Scott Air Force Base's southeast corner shut down in 1977.
But it wasn't until last year that the Air Force closed the landfill properly, with a plastic "geo-membrane" cover and soil cover, costing taxpayers more than $20 million.
Now the Air Force is preparing to spend another $4.6 million to prevent potentially dangerous chemicals from leaking into nearby groundwater.
That's the estimated price tag for a plan that Air Force officials intend to recommend during a public hearing set to begin at 6 p.m. Wednesday at MidAmerica St. Louis Airport, near Mascoutah.
The final cost for the cleanup could take years to determine, depending on the methods selected for monitoring and removing the chemicals.
"We have multiple alternatives that we're going to show the public," said Richelle Collingham, a civilian employee at Scott in charge of environmental restoration projects.
Air Force officials intend to present four alternative plans for cleaning up the chemicals that are leaking from the site, which received unregulated waste since the 1940s, when it opened, according to Collingham.
"Back in the '40s, the '50s, the '60s, it was how everybody disposed of waste," she said. "We threw everything away back then."
A very small likelihood exists of landfill chemicals entering local drinking water sources, said Paul Lake, who oversees federal remediation programs for the Illinois Environmental Protection Agency.
"There are no current users that we're aware of the groundwater there," Lake said. "Unless something comes to light, there is no reason to believe that this contamination is going to get into anybody's drinking water."
Groundwater samples collected near the site beginning in 2009 indicated the presence of several dangerous chemicals, including trichloroethylene, vinyl chloride and arsenic, according to a report on the landfill filed with the Illinois Environmental Protection Agency.
The landfill shut down in 1977, apparently when it ran out of space for more trash. In recent years, however, the landfill was identified as a target for an officially sanctioned cleanup as part of a Defense Department environmental restoration program, according to Lake.
Although 40 cleanup sites, including underground fuel storage tanks, have been identified on Scott, "the biggest project by far is the landfill," Lake said.
Collingham is scheduled during the Wednesday meeting to present four alternative plans for dealing with the chemical run-off, with each plan contrasting with the others in terms of price and timetables.
The plans range in cost and complexity beginning with taking no action at all, which carries an estimated price tag of zero dollars.
The fourth alternative calls for the construction of an "anaerobic bio-remediation barrier" on the base's boundary, along with on-site barriers for immobilizing metals in the tainted groundwater. Its projected price tag is about $10.7 million and would require about 30 years to complete.
The Air Force intends to recommend the second alternative, which calls for the dechlorination of "chlorinated" volatile organic chemicals. This method -- the second cheapest -- carries a proposed long-term price tag of about $4.6 million, or slightly more than $140,000 per year for 30 years, according to Air Force plans.
This compares to the most expensive option, the third alternative, which calls for "in situ" aerobic and anaerobic bio-remediation for chlorinated VOCs and in situ chemical mobilization for metals.
Its estimated price tag comes in at about $36.3 million and would take 15 years to complete, according to the report.
No matter the option chosen, cleaning up the leaking chemicals will likely take a long time, Collingham said.
"When you talk about groundwater contamination, and it's really important that people would come to the meeting and listen to this, we talk in terms of years," she said.
Contact reporter Mike Fitzgerald at firstname.lastname@example.org or 618-239-2533.