Laserfiche WebLink
Month <br />Potential <br />ET (in.) <br />Precipitation <br />(in.) <br />Actual <br />ET (in.) <br />Runoff <br />(in.) <br />Infiltration <br />(in.) <br />Percolation <br />(in.) <br />October <br />3.36 <br />1.51 <br />1.36 <br />0.15 <br />1.36 <br />0.00 <br />November <br />2.19 <br />1.05 <br />0.95 <br />0.11 <br />0.95 <br />0.00 <br />December <br />0.48 <br />0.85 <br />0.48 <br />0.09 <br />0.77 <br />0.00 <br />January <br />0.47 <br />0.88 <br />0.47 <br />0.09 <br />0.79 <br />0.00 <br />February <br />1.94 <br />0.76 <br />1.30 <br />0.08 <br />0.69 <br />0.00 <br />March <br />2.93 <br />1.04 <br />0.94 <br />0.10 <br />0.94 <br />0.00 <br />April <br />3.70 <br />1.01 <br />0.91 <br />0.10 <br />0.91 <br />0.00 <br />May <br />4.93 <br />0.94 <br />0.84 <br />0.09 <br />0.84 <br />0.00 <br />June <br />5.72 <br />0.47 <br />0.43 <br />0.05 <br />0.43 <br />0.00 <br />July <br />6.34 <br />1.18 <br />1.06 <br />0.12 <br />1.06 <br />0.00 <br />August <br />5.74 <br />1.35 <br />1.22 <br />0.14 <br />1.22 <br />0.00 <br />September <br />4.43 <br />1.50 <br />1.35 <br />0.15 <br />1.35 <br />0.00 <br />Annual Total <br />42.33 <br />12.55 <br />11.29 <br />1.25 <br />11.29 <br />0.00 <br />• Estimate runoff and evapotranspiration (ET) for the rock pile; <br />C \Users1cwoodward1Desktop \Sundays \FINAL - Environmental Protection Plan Sunday Mines Revised January 2012 docx <br />Section 13 <br />Geochemical Data and Analysis <br />infiltrates into the pile may be subsequently removed from the pile by evaporation or <br />transpiration or the water may move downward in the pile and become percolation. <br />Empirical information such as temperature and precipitation data and development <br />rock characteristics are used for the water balance evaluation. The procedure included <br />the following activities: <br />• Compile temperature and precipitation data from a location as close as possible to <br />the site; <br />• Estimate moisture holding capacity of development rock based on site specific <br />capillary moisture data obtained from soil water characteristic curve (SWCC) <br />testing; and <br />• Estimate percolation through the development rock pile using a water balance <br />approach. <br />Details of the estimation method are included in Attachment 0 of this report. <br />Development rock samples were collected for physical property analyses including <br />soil water characteristic curve (SWCC) testing. Geotechnical laboratory data for the <br />development rock samples, including SWCC testing data, are also provided in <br />Attachment 0. Exhibit 13 -1 presents the results of monthly percolation estimates for <br />an average precipitation year. <br />Exhibit 13 -1. Estimated percolation through development rock areas for average precipitation. <br />The estimate summarized in Exhibit 13 -1 indicates that potential ET at the Sunday <br />Mines Group exceeds average precipitation by a ratio of approximately 3.4 to 1. <br />Under average conditions, available ET is adequate to evaporate water infiltrating the <br />surface of the rock piles. A temporary increase in stored soil moisture would occur <br />during the months of January and February, but this water would be removed from <br />13 -6 <br />