Laserfiche WebLink
Responsiveness Summary for the <br />Underground Injection Control Class V Final Permit Decision <br />for the Powertech (USA) Inc. Centennial Site <br />Background <br />On April 30, 2009, the EPA received an Underground Injection Control (UIC) Class V <br />permit application from Powertech (USA) Inc. to reinject groundwater pumped from the Upper <br />Fox Hills Formation, A2 sandstone during an aquifer-pump test. The proposed injection well is <br />located at the Centennial site in Weld County, Colorado, in the NE quarter of Section 33 in <br />"township 10 North and Range 67 West. Powertech proposes conducting an aquifer-pump test at <br />the site, which will involve pumping groundwater from the A2 sandstone within the Upper Fox <br />Hills Formation. The groundwater will be stored temporarily in enclosed, above-ground, storage <br />tanks. Powertech proposes reinjecting the stored groundwater back into the A2 sandstone using <br />the same well that was used to pump the groundwater to the surface during the aquifer-pump <br />test. <br />The purpose of the aquifer-pump test is to collect geologic and hydrologic information <br />and other information about aquifer characteristics. Most importantly, the aquifer-pump test will <br />seek to verify that the A2 sandstone is hydrologically isolated from other aquifers by <br />impermeable confinement zones lying directly above and below it. Powertech plans to include <br />this information in a UIC Class III permit application for the in-situ recovery of uranium that will <br />be submitted to the EPA some time in the future. The EPA has not yet received a UIC Class III <br />permit application from Powertech for the in-situ recovery of uranium at the Centennial site. <br />The UIC Class V permit will allow only the reinjection of groundwater. The UIC Class V Final <br />Permit does not authorize any injection activity for the purpose of uranium recovery. <br />The injection well is screened only within the A2 sandstone aquifer in the Upper Fox <br />Hills Formation. The Laramie Formation overlies the Fox Hills Formation; therefore, the <br />injection well intersects the Laramie Formation. The groundwater in the A2 sandstone contains <br />concentrations of constituents regulated under the Safe Drinking Water Act (SDWA) that exceed <br />drinking water standards. These constituents include uranium, antimony, and radium. The <br />Laramie Formation contains aquifers that do not exceed the SDWA drinking water standards for <br />uranium, antimony, and radium. The main purpose of the UIC Class V Permit is to protect the <br />aquifers in the Laramie Formation from contamination during injection. <br />On June 15, 2009, the EPA issued a Class V UIC Draft Permit and published notice of <br />this Draft Permit in The Tribune in Greeley. The public notice announced a public comment <br />period and a public hearing for the Draft Permit. The EPA held a public hearing on July 20, <br />2009, in Greeley, Colorado. The public comment period for the Draft Permit began on June 19 <br />and ended on July 24, 2009. The EPA received comments from the public on the draft permit <br />during the public comment period and the public hearing. One of the comments received <br />identified that multiple permit numbers were incorrectly used in the Draft Permit, and indicated <br />that this was potentially confusing to the public. In response to this comment, the EPA issued a <br />second Class V UIC Draft Permit with the corrected permit number. Public notice of the second <br />Page 1 of 24