Laserfiche WebLink
44 <br />1 to estimate the effect of the mine discharges is used. Unfortunately, there <br /> is no effective means of directly measuring the quantity of water passing • <br /> through the waste dump and it is necessary to estimate the deep percolation <br /> through the use of water balance procedures. <br /> This analysis of hydrologic balance is restricted to the refuse dump <br />! <br />1 at the Allen Mine. A map of the dump is presented in Figure 13, The <br /> water balance is analyzed on an average annual basis using long term mean <br /> climatic data where available. The overall hydrologic system is broken <br /> dawn into two subsystems, the subsurface water budget and the surface water <br />~ ~ budget. The two subsystems are linked by infiltration (see Mchlhorter, 1980, <br />l~ for basic details). <br />J <br />Climatic Summary - Precipitation, temperature, and solar radiation data <br />J 1 utiltied in the computations are presented in Table 9. Mean temperature <br /> and precipitation data based on 20 years of retord are available at 7rini- <br /> ~ dad approximately 25 miles east of the A11en Mine and at North Lake approxi- <br />J J mately five miles west ,of the Allen Mine. Elevations at these two sites <br />, are 6030 feet and 8800•feet, respectively, while the elevation of the refuse <br />~ pile is approximately 1470 feet. The means for these two locations show <br /> substantial variation, probably due to elevation differences, Therefore, <br /> . <br />the mean precipitation and temperature data presented in Table 9 were ob- <br /> tained by interpolating on elevation between data for Tr-inidad and North <br /> <br />I i Lake. (The means far Trinidad and North Lake are presented in Appendix F.) <br />' Solar radiation data i{ available at only a few locations in Colnrado, all <br /> of which are some distance north of the mine site. For this reason the amount <br /> ot.solar radiation was calculated using a method presented by Jensen (1973). <br /> Details and comparative data are presented in Appendix F. <br /> Potential Evaporation - The amount of water lost to the atnaspher•e was <br /> calculated by dividing the year into a winter season (Nov. through Mar.) <br />~ and a growing season (Apr. through Oct.). Winter period losses result from <br /> sublimation and evaporation and were estimated using the following equation <br /> (Wymore, 1974). <br /> (0.0067 + 0.05) R <br />E <br />• K <br />C <br /> s <br />w <br />c <br />in which Ew represents evaporation losses from snow pack (inches), i <br />represents mean monthly temperature (oF) Rs is the solar radiation (ly./d) <br />1 <br />