Laserfiche WebLink
1996 Annual Hydrologic Report <br />• Page 5 <br />reclaimed Northwest Intake Portal. The results of monitoring are include in the Mine Water section, <br />Table M96-3. <br />Mine Water <br />The annual mine inflows study for this year was taken the end of September 1996. This study is <br />being made a part of the AHR. The results of the study aze given on data pages MA-13 thru -15 and <br />MB-10 and 11. A summary of past conductivity and flows from the monitoring locations aze given <br />on Tables M96-1 thru 5. Inflow monitoring locations aze shown on the 1996 Mine Inflows Map. <br />As usual there aze many differences in the monitoring results at the Roadside South Portal. These <br />differences aze primarily the result of changes in mining locations; differences in water routing, <br />piping and pumping patterns; and general difficulties involved with monitoring underground. <br />Location 3 showed more flow this Year than normal but it did not appear to be related to surface <br />imgation. The big change this yeaz was the lazge decreases in flow from the south end of the mine. <br />Monitoring at locations 24, 25, and 27 thru 31 was discontinued due to sealing of the south end of <br />the No. 2 South Mains. Flow from these locations is piped from these seals and is now monitored <br />as new location 34. Flows at locations 14, 32, 5 and 10 were greatly reduced by this change. A <br />• pump was set up neaz location 5 on the pipe line draining location 34 to provide the mine with water <br />for dust control and fire fighting. Flows from sealed panels at locations 26,15 and 6 dried up as well <br />as location 16. The reduction in flow from these sites may have corresponded to increased inflows <br />in the 6th East Panel. This panel was completed and sealed in June of 1996 and inflows into the <br />panel were not accessible for monitoring at the time of the mine inflows study. The "total inflows" <br />in the last column of Table M96-3 shows increasing inflows in May and June, then a sharp drop. <br />This corresponds to increased inflows in the 6th East panel until it was sealed near the end of June. <br />The sharp drop in inflows corresponds to the inflows diverted to filling the abandoned 6th East panel <br />at the time of the study. The lower flow at location 33 is typical of a reduction in flow a yeaz or so <br />after mining an azea. Locations 8 and 9 showed flow again appazently due to better handling of <br />water along the belt line. In most cases the conductivity continued to be similaz to previous <br />readings. Location 23 showed a significant drop which was likely due to less concentration as a <br />result of evaporation. Conductivity at location 34 was higher than the corresponding sources from <br />previous studies. 'This is typical of water setting in a sealed azea prior to dischazge. The mass <br />average pH and conductivity for the inflows was 8.3 and 1207 umhos/cm respectively. Using the <br />average pH, conductivity and dischazge for 001 and 002, the mass average pH and conductivity <br />discharged during the yeaz was calculated to be 7.7 and 2254 umhos/cm. Table M96-3 was prepared <br />to estimate the total inflows and discharges from the Roadside South Portal but does not include the <br />water consumed for mining purposes as discussed in the Consumptive Use section of this report. <br />For the inflow calculation, an attempt was made to account for water level changes in the old <br />portions of the mine. Negative values of "water level" flow represent periods when the water level <br />• was decreasing as a result of discharge being greater than the inflow. The calculated inflows for <br />September without considering the filling of 6th West panel were 135.1 gpm which is more than <br />