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III IIIIIIIIIIIIIIII STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman SI., Room 215 <br />Denver, Colorado 80203 <br />Phone. 13031 866-3 56 7 <br />FAx~(303)832-8106 <br />DATE: <br />TO: <br />FROM: <br />RE: <br />May 7, 1998 <br />Jim Burnell M <br />Dan Mathews ~~ <br />~'an.t ; ~~ T z,,,,o~e ~~y~ <br />~~ s, 1 ~~ re.le~f r <br />DEPARTMENT OF <br />Goy--~,oo-ale.-We ~`" NATURAL <br />a .~,~r„l~ ~~f Qlvi / RESOURCES <br />(,.,)L`~ ~ L ~ Cr.c..~tl Ja~ L~ yA~~ Roy Romer <br />~-[ ~ ~ ~ ~n ~ Governor <br />•l ' lames S LoChhead <br />E~em~ive Director <br />Michael B. long <br />Division Director <br />Red Canyon Mine 1997 Annual Hydrology Report <br />Permit C-81-034 <br />Enclosed is a copy of the referenced AHR, along with a review checklist that I filled out, <br />documenting that all monitoring and reporting currently required by the permit was performed, <br />and included in the AHR. Also included in the report this yeaz is an analysis of return flow <br />irrigation water from the sediment pond, which was provided to demonstrate water quality <br />suitability for postmine wildlife and livestock use, as required for permanent impoundments. <br />The only specific question I have concerns the E Seam piezometer (E-1). The water level <br />reported for May, and September, 1997, (6376.3 and 6377.2, respectively) is approximately 20 <br />feet higher than the 1980-1994 average, and approximately 10 feet higher than 1995 levels. The <br />second paragraph on page 4 of the report briefly discusses the water levels. The paragraph refers <br />to the 1987 AHR as projecting that mine workings water level would reach a level of 6355', in <br />1993. I'm not sure what the significance of 6355' elevation is, and I don't have a copy of the <br />1987 AHR, but E-1 water level exceeded this elevation as early as 1985. Does E seam <br />piezometric water level in well E-I correspond to mine water levels? The AHR says this is <br />"unlikely". The AHR and PHC both project that water in the mine will stabilize below the <br />elevation of the portal, such that no surface discharge would occur (the AHR indicates a portal <br />elevation of "approximately 6400 feet"; the PHC indicates the portal elevation was 6390 feet). <br />What is the significance of the rising water levels in E-1? If E seam piezometric elevation <br />eventually exceeds portal elevation (within 3-5 years at present rate, depending on true portal <br />elevation), does it follow that mine water will back up to portals and discharge? Maybe the <br />"mine filling schedule" in the referenced 1987 AHR addresses these issues. Should we be <br />concerned? <br />cc: Larry Routten <br />rcan\97ahr.mem <br />