1993-02-22_REVISION - M1988112 (2)

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1 • III IIIIIIIIIIIII III • STATE OF COLORADO DIVISION OF MINERALS AND GEOLOGY Department o! Natural Resources i 1 31 3 Sherman 51 Rppm 21 5 Denver, CO 80203 Phone: (3031 dbfi-3567 FAX:Ia031832 dIOG DATE: February 22, 1993 ~~ T0: James Stevens /fix ~~ FROM: James Dillie ,may. RE: Plume Analyses, Battle Mountain Project, Collection Pond Ledk Using M-9 Well to Monitor Aquifer pF Cprp tir.~ ~~n o re]6 Roy Rumor Goeernnr M id~ael B. Lnnp D rvision Duer trn I have yet to find the correct plotting soft-ware in-house to print mut the various plumes that I developed during the analyses. Randy Price is trying to find a public domain package we can use for the printouts. I did hamd draw (from the monitor) a couple of the plumes. 1. The first analysis I made contained the following assumptions: a. Dispersivity - Dx = 30, Dy = 10 b. Detection limit - .005 mg/1 c. Time - 9 years d. Seepage velocity - .048 ft/day e. Contaminant - 2.5#/day f. Porosity - varied from .20, .25 to .35 Result - M-9 well will not detect the contaminant in 9 years. It would take 15-16 years. This agrees with BMG results. 2. Second set of assumptions a. Dispersivity - Dx = 100, Dy 30 & Dx = 200, Dy = 60 b. Rest of the assumptions are the same as above. Result - M-9 well will detect the contaminant in 9 years. As a matter of fact, the well should detect the contaminant in 7 years but not before (except for Dx = 200, Dy = 60 which would detect the contaminant in 5 years). This agrees with BMG. 3. If the dispersivities are kept at Dx = 100, Dy = 30, seepage velocity is the same, porosity is .25 and time is 9 years, the M-9 well should detect the contaminant even if the concentration of contaminant at the '.point source leak drops down to .04#/day. Below .04#/day it will take a few more years to reach the M-9 well.