Laserfiche WebLink
DEPARTMENT OF NATURAL RESOURCES <br />David M. Getchea Executive Director <br />MINED LAND RECLAMATION DIVISION <br />DAVID C. SHELTON, Dlnotor <br />Fichard D. Lamm <br />Governor <br />T0: Mark Lo ye <br />l ,~ <br />FROM: Bob Liddle ~~ ~ <br />DATE: March 27, 1984 <br />Permit #:~ 77 -~jd¢ Confidental?: ~_ <br />Class: Type-Seq.: <br />From: To: <br />Doc. Name: R$~ y~~ <br />Doc. Date (if no date stamp): _ <br />RE: Homestake Pitch Mine Project #77-44R <br />Comments on Homestake's Amendment <br />I have reviewed the hydrologic aspects of the Homestake Amendment submitted on <br />January 19, 1984. I identified concerns pertaining to hydrologic impacts, <br />drainage control, and reclamation. The following are my comments on the <br />amendment. <br />Hvdrolooic Impacts <br />The operator submitted a study entitled, Assessment of Potential for <br />Environmental Dispersion of Constituents of the Reclaimed Low Grade Ore Piles <br />at the Pitch Mine by bames and Moore. The purpose of the study was to <br />establish, from analysis of potential worst-case conditions, the environmental <br />Concentrations of radionuclides and trace metals resultant from migration <br />through reclaimed low grade ore piles. The following are my comments on the <br />study: <br />1. The study attempted to predict ]eachate concentration by assuming a <br />linear relationship between leachate transit time in the pile and <br />laboratory leaching time. The ratio used 1n the study was 100 min:10 <br />days. it might be appropriate to discuss the validity of the assumption <br />of a linear relationship and how this assumption affects the <br />conservative nature of the prediction. <br />2. It was not mentioned in the report what solvent was used in the <br />laboratory leachate analysis. This should be included to make it clear <br />how the analysis was done. <br />3. Pages 5 through 7 of the study present a table of estimated leach <br />fractions. It does not appear that the units or values are correct. <br />For example, uranium rock material is listed as 503 X 10 to the third <br />power milligrams per gram. This indicates that there are 503,000 <br />milligrams of U in one gram of rock material, which is not possible. The <br />leachate concentration also indicates high values. For example, barium <br />is listedos 46 mg/ml which is 46,000 mg/l. Uranium is listed as <br />86,000,000 mg/1. These are both very high values. The applicant should <br />ezamtne the values and units in the table and address their accuracy. <br />423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tei. (30z) 866-3567 <br />