Laserfiche WebLink
III IIIII999 IIII III <br /> STATE CI COLORADO <br /> DIVISION OF MINERALS AND GEOLOGY <br /> Department of Natural Resources <br /> 1313 Sherman St.. Room;15 DIVISION O F .A <br /> Denver, 866-rado 567 DENVER OFFICE 4 <br /> FAX: <br /> (313031 8GG 35G7 RECEIVED MINERALS <br /> FAX:(303)832-8106 & <br /> PUBLIC FILE COPY G E O L O G YI <br /> 'JUN 18 1999 FILE. RECLAMATION <br /> June 15, 1999 m—�'/-O�f9 MINING-SAFETY <br /> Division of Minerals 8 Geoiaer SITE: <br /> oc✓art�Li/,Y�_ Bill ovens <br /> Jerry Sandell Govemo, <br /> Calco, Inc. Greg E.Walche, <br /> P.O. Box 1044 becunve Directo, <br /> Salida, CO 81201 Michael R Lone <br /> Division Di,ector <br /> RE: Reduced Monitoring Frequency and Parameters, Howardsville Mill, Permit No. M-84-049. <br /> Dear Mr. Sandell: <br /> I <br /> Please find enclosed, DMG 6/11/99 memo from H.H. Posey, addressing reduction in the sample <br /> frequency and analytical parameters for the hydrologic monitoring plan for the Howardsville Mill; and <br /> 10 pages of hydrologic data from Howardsville Mill samples; and table 2.6 and 2.7 from Guidelines <br /> for the Characterization, Monitoring, Reclamation and Closure of Cyanide Leaching Projects, "Cyanide <br /> Guidelines for Colorado", pages 49-51, March 1999. <br /> As noted in DMG's 6/11/99 memo, DMG approves your 4/12/99 request for reduction in sample <br /> frequency from the existing quarterly sampling to twice-yearly. The twice-yearly samples shall be <br /> taken once during high flow and once during low flow conditions. <br /> As noted in DMG's 6/11199 memo, DMG approves the following analytical parameters for the twice- <br /> yearly samples: pH for surface and groundwater shall be measured in the field and at the lab; <br /> conductivity for surface and groundwater shall be measured in the field and at the lab; hardness <br /> (calculated) is required for surface samples only; Sulfate for surface and groundwater; Calcium for <br /> surface samples only; Magnesium for surface samples only; Aluminum for surface samples only; <br /> Arsenic for surface and groundwater; Barium for surface and groundwater; Boron for surface and <br /> groundwater; Cadmium for surface and groundwater; Copper for surface and groundwater; Iron for <br /> surface and groundwater; Lead for surface and groundwater; Manganese for surface and <br /> groundwater; Mercury for surface and groundwater; Silver for surface and groundwater; and Zinc for <br /> surface and groundwater. DMG may consider a more abbreviated parameters list, subsequent to <br /> completion of three additional sampling periods, necessary to better define background conditions. <br /> Analytical detection limits shall remain as previously approved for the 5 quarters of baseline <br /> monitoring. Please continue to provide sample numbers, sampling dates, sample type (integrated or <br /> grab) and flow data for surface samples, and depth to water level for groundwater samples. <br /> SincerelyV —// <br /> Wallace H. Erickson <br /> Environmental Protection Specialist <br /> Enclosures <br /> cc: Harry Posey, DMG <br />