Coronado National Forest will start work next month to clean up at least 300 tons of lead-contaminated soil from three recreational target-shooting sites in Redington Pass northeast of Tucson.
Toxic lead is present in soil at these sites in concentrations of more than 80 times higher than federally recommended cleanup levels, the Forest Service says.
In part because of the cleanup, the Forest Service plans to keep the three sites closed to the public possibly until Sept. 30, 2014. That would be a full year after the original planned reopening date of Sept. 30 of this year.
The extended closure will also allow time for soil testing and some land revegetation once the cleanup is done, the Forest Service said.
The three target-shooting sites, totaling 2.5 acres, have been closed since January to allow authorities to remove shooting debris and conduct a health risk assessment of the area.
The assessment, done in April, found lead levels in soil ranging from 10 to 68,000 parts per million.
The Environmental Protection Agency recommends cleaning lead from soil in nonresidential areas at levels of 800 parts per million, a Forest Service spokeswoman said.
Lead occurs naturally in soil at levels of 50 to 400 parts per million, the EPA says.
The Redington Pass risk assessment had recommended cleaning the soil to 1,572 parts per million. But after reviewing the matter, the Forest Service decided the EPA-recommended level of 800 parts per million would be preferable, said service spokeswoman Heidi Schewel.
The more stringent cleanup level is best suited to this area due to its frequent use by the general public and by nearby residents, Schewel said.
The soil cleanup should be finished by mid-November, Schewel said, although authorities may in the end need to remove additional soil.
Looking ahead, Forest Service officials will try to figure out how to best prevent future contamination when the agency, working with partners, develops a Redington Pass Collaborative Management Plan.
In addition, the Forest Service is working with an applicant on a proposal for a managed shooting range in Redington Pass.