he site," said Paul Eger, a Consultant and Environmental Engineer. Acidic drainage from the waste rock piles ran into Birch Lake and the Kawishiwi River watershed causing serious contamination. :There were elevated concentrations of metal in the water," said Kim Lappako of the Minnesota DNR. The problem wasn't actually discovered until the late 1980s. "All of this operation started before there was environmental review, before there were permitting programs, before most of the environmental regulations were in place," said Ann Foss of MN Pollution Control Agency. Once discovered the DNR and MPCA worked jointly to find a way to stop the drainage and clean up the watershed. "The agencies have worked successfully on resolving that problem, even though not even one of us had anticipated this kind of a problem when they first started the operation," said Foss. Five large waste rock piles were created and experimental treatments were put in place. The idea was to reduce the levels of heavy metals in the discharges and neutralize the acid. "We looked at the different compositions of rock, looked at the water quality, looked at the potential risks," said Eger. The agencies designed synthetic liners to cover the rock piles to block the air from converting the sulfides to acid and created wetlands to filter out heavy metals before they could get to the rivers and lakes. Through years of testing and adjustments, the site now has operation permits from the MPCA...albeit with variances that allow heavy metals to leach out in amounts higher than current state standards. Eventually we'll reissue that permit, and we hope to be able to reissue it without a variance from the metal standards. "You can see that it kills things and the state has not only, has done little or nothing, and when they did something, one of the primary things they did was to provide variances," said Kimmer. Effective treatment is critical because everyone agrees that acid drainage can cause damage that lasts for centuries. "There is examples of mine drainage problems that date back to mining that the Romans did. So yeah, this is centuries of problems," said Eger. "Today there are existing, stringent rules and laws in place before you begin to mine...so you don't end up with centuries old problems they had in Roman times," Cherry said. These days the MPCA continually monitors the Dunka site and state reports indicate that recent testing shows little quantifiable environmental impact at the site. "Have been treating drainage at that facility successfully for, this is their 20th year," Eger said. There are several companies looking to open copper-nickel mines in the Duluth Complex with PolyMet being the closest to getting the permits needed to begin operations. The scientists say the lessons learned at the Dunka mine are being put to good use as they work to make sure the environment is protected at the proposed new mine sites. Barbara will talk more about those protective steps tomorrow.