Laserfiche WebLink
r 999 <br /> STATE OF COLOKADO <br /> DIVISION OF MINERALS AND GEOLOGY <br /> Depannient of Natural Resources <br /> 1313 Sherman Sherman 51., Room 215 <br /> Denver.Colorado 80203 <br /> Phone:(303)866-1567 <br /> FAX:(303)832 s 106 DEPARTMENT c 31 <br /> NATURAL <br /> RESOURCE') <br /> � Rnv Roma <br /> Governor <br /> lames 5 Lochhead <br /> DATE: December 7, 1995 r e.,cw we DnecIoF <br /> Michael 8,Lung <br /> Divilnn Dnecvx <br /> TO: Wally Erickson <br /> FROM: Harry Posey W <br /> RE: Howardsville Mill <br /> In light of what I understand to be some of the lingering questions about the geochemical conditions <br /> at the Howardsville Mill site, I have prepared this memo report. It contains some observations and <br /> interpretations about the effects of tailings on ground and surface water, and the outlines of a <br /> recommendation for essential future ground and surface water monitoring. <br /> BACKGROUND <br /> From the maps and data received on December 7, I constructed a set of contour maps for pH, TDS <br /> and SO„ plotted by year, and checked the metals data to help shed light on the groundwater <br /> situation at Howardsville. <br /> As I understand the problem, you want to determine whether tailings deposited under the permitted <br /> operation are causing adverse impacts to groundwater and/or surface water, and whether a lined <br /> tailings pond is leaking. In addition, you need to determine what type of monitoring may be <br /> necessary to gauge impacts to the hydrologic balance now that some of the earlier-functioning <br /> monitor wells have been abandoned. <br /> As you have indicated, the situation is complicated by the presence of two sets of tailings, both of <br /> which were deposited from the Howardsville mill: (1) a pre-law tailings deposit, and (2) a permitted <br /> deposit. The geochemical setting is also complicated because some of the permitted tailings were <br /> deposited above pre-law tails. <br /> You have also indicated that all of the tailings rest on a discontinuous veneer or discontinuous <br /> interlayers of tails and alluvium which were washed in from upstream operations. That said, I think <br /> it may not affect your interpretations appreciably, because these tails probably have been more <br /> 1 <br />