Does Mining Pollute the Water?
In most of our aggregate mining operations we do not discharge water because we recycle water during mining and processing operations. Typically, water from on-site surface water sources (including the capture of storm runoff) is used to wash the silts and clays out of the sand and gravel, so the finished products are clean for market applications. The wash waters containing silts and clays are pumped into a sedimentation pond, allowing the fines particles to settle out on-site. “Clean” wash water is then recycled back to the processing plant for continued use in the washing process. In addition, some of the water retained by on-site surface water sources is lost to evaporation or infiltrates into subsurface flows. The IEPA, Bureau of Water is in charge of enforcing Federal and State water pollution regulations. Mine operators are required to obtain an Operating Permit from the Bureau of Water for the regulation of storm and process waters within a mining site. Depending on the type of
