Laserfiche WebLink
31 <br />i <br />Approximateiy 2 years of discharge data for the Allen and Maxwell Mines <br />- are tabulated in Appendix C, Table C1. The mean discharge from the Maxwell <br />is 15 gpm which falls within the range shown in Table 4. The mean discharge <br />for the Allen Mine is 73 .gpm. Comparison of the present Allen and Maxwell <br />discharges with those calculated in Table 4 suggests that a high degree of <br />1 confidence can be placed on the calculated discharges. This comparison also <br />indicates that the controlling hydraulic and geologic parameters at the <br />I~ Maxwell are very similar to those at the Allen. <br />i <br />Alluvial Studies <br />l~ <br />Investigation of the near-surface ground water along the Purgatoire <br />River in the study area was made by drilling 8 holes through the alluvium <br />to bedrock and the excavation of several backhoe pits. From the informa- <br />,, Lion obtained, two cross sections, showing the alluvial and strath terraces, <br />///~, were prepared and are shown on Plates 2 and 3 in the map pocket. The <br />iocations of the sections are indicated on Plate 16. Of particular importance <br />to the hydrologic investigatlan is the fact that ground water was encountered <br />only in the alluvium directly in contact with the river and that the thickness <br />,_ and lateral extent of this material is quite limited. <br /> <br />Three of the 8 holes were drilled and cased at the A11en Mine and will <br />be discussed further in the Context of the water quality investigations. the <br />remaining 5 holes were drilled at the Maxwell study area and three of these <br />wells were cased with perforated steei casing. The locations of the cased <br />wells are indicated on Plate 18 where it is shown that wells Al 3-3 and <br />AL 4-2 are on the upstream (west) and downstream (east) boundaries of the <br />Maxwell study area (respectively), immediately adjacent to the stream. Welts <br />AL 1-1, AL 1-2, and AL 2-1 are located in the immediate vicinity of the <br />active waste dump at the A11en Mine. <br />Auger hole tests were performed to determine the hydraulic ~nductivity <br />of the alluvual materials. The procedures for conducting and analyzing auger <br />hole tests are described in Bavel and Kirkham (1948) and in the National <br />1 Engineering Handbook, Section 16, United States Soil Conservation Service. <br />The auger hole data are presented in Appendix D, Tabie DI through D3 and the <br />i analyses are shown on Figures 8 through 10. The hydraulic conductivity <br />/ I;- <br />