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<br />May 14, 2010 <br />C ITY oFARUADA <br />OFFICE OF THE CITY MANAGER <br />FACSIMILE: 720-898-7515 A TDD: 720-898-7869 <br />PHONE: 720-898-7500 <br />David Berry <br />Colorado Dept of Public Health and Environment <br />Division of Reclamation Mining and Safety <br />4300 Chevy Creek Dr. S. <br />Denver, Colorado 80246-1530 <br />Subject: Schwartzwalder Mine Environmental Protection Plan <br />The City of Arvada appreciates the opportunity to comment on the draft Schwartzwalder Mine <br />Environmental Protection Plan (EPP) that has been developed by the Cotter Corporation (Cotter). The <br />City has only recently been made aware of the contamination of Ralston Creek from uranium and we are <br />looking to the Colorado Department of Public Health and Environment (CDPHE) to provide prompt and <br />effective corrective action. Recognizing an inactive mine site and surface water, contamination involves <br />multiple state agencies that include Division of Reclamation Mining and Safety (DRMS) and the <br />Radiological Division and Water Quality Control Division (WQCD). We strongly encourage and <br />support close collaboration among responsible regulating agencies. <br />By Cotter's own admission in the 2009 Schwartzwalder Mine Semiannual / Annual Radiological <br />Monitoring and Effluent Report (March 30, 2010), Ralston Creek has been impacted by past mine <br />operations: <br />"Surface water in Ralston Creek adjacent to and below the mine and the remaining <br />licensed area has been impacted in recent years by residual contamination from past <br />operations within alluvial fill materials." (page 24) <br />"Beginning in late 2002, there were notable increases in uranium concentrations in the <br />creek downstream from the mine site. The observed "peaks" are generally believed <br />attributable to termination of WWTP operations in June 2002, followed by cyclic <br />"flushes" driven by seasonal runoff cycles. In 2008, pump back operations from the <br />lower sump to an upper sump, which had created a hydraulic barrier between <br />groundwater in the alluvial fill and surface water in Ralston Creek, were terminated <br />resulting in additional concentration increases in 2008/2009." (page 24) <br />"Four (4) sumps were also installed at the site in 1990 to intercept groundwater and <br />pump it to the WWTP for contaminant removal before discharging treated water into <br />Ralston Creek. The sumps were operated in this fashion until 2002. From 2002 until <br />2008, water from sump 1 continued to be pumped back to sump 3 to create a re- <br />circulating hydraulic barrier between groundwater in the alluvial fill and surface water <br />in Ralston Creek. This practice was discontinued in 2008 due to concerns of potentially <br />violating regulations. Concentrations in Ralston Creek increased as a result of <br />termination of this interim mitigation measure." (page 30) <br />P.O. BOX 8101 A 8101 RALSTON ROAD A ARVADA, COLORADO A 80001-8101