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<br />' Annual Hydrology Report <br />April 28, 1988 <br />Page 8 <br />1.4 Mine Water Monitoring <br /> Mine inflows in azeas being actively mined were mapped on an ongoing basis in <br />' water year 1987. Areas of previous mine inflows were monitored by occassional <br /> visits and by sampling of flow and quality during dewatering operations. <br />' Exhibit II shows locations <br />sampling locations and estimated amount s of mine inflows as well as <br /> . <br />Inflows into previously mined areas along Sylvester Gulch and near the main <br />' portals continued to be highly responsive to the spring runoff season. Exhibit <br />II shown estimated average flows for the spring runoff season and the low flow <br />time of year, as well as hydrologic conditions which were encountered in areas <br />' mined during water year 1987. <br />Inflows appeared to be about the same as in 1986 for areas around Sylvester <br />' Gulch. More effort was spent in 1987 to dewater the inflows near the Sylvester <br />Gulch Fan. Resultantly, a much higher discharge ampunt is listed for the NPDES <br />point 011. The dewatering effort was undertaken to try to prevent additional <br />floor heave in the area, due to water saturation, and to improve ventilation by <br />' decreasing standing water. <br />The discharge from the mine portal areas was approximately the same as 1986. <br />' Areas along Sylvester Gulch Main Mine Fan entries produced measured flows <br />ranginy from 2 GPM during low flow conditions, to 6 GPP4 during spring runoff <br />conditions, and 3 GPM during low flow conditions to 9 GPM during spring runoff <br />conditions, for two locations which were checked. See Exhibit II for locations <br />of flow measurements. Areas of standing water were also mapped and aze shown on <br />Exhibit II. <br />' The old Sylvester Gulch area (entries 14 through 21, main intakes) produced <br />estimated flows ranging from 0 GPM during low flow conditions to 1 GPM during <br />' spring runoff conditions. Exhibit II shows the location of this flow <br />measurement. <br />The main portal area (entries 1 through 5) had estimated flows ranging from 0 to <br />' 0.25 GPM during low flow condition and 1 to 3 GPM during spring runoff <br />cronditions. <br />' Entry O1 and 1 on the east side of the main intake from crosscut 1 to crosscut 7 <br />had standing water year round and flows were estimated at 0.0 to 0.5 GPM during <br />low flow conditions and 2 to 5 GPM during spring runoff. <br />' Entry 8 and 9 on the west side of the southwest main intakes from portal entry 5 <br />to crosscut 7 produced flows estimated at 0 to 0.25 GPM during low flow <br />conditions and 0.5 to 1.0 GPM during spring runoff conditions. <br />' These flows are similar in both quality and quantity to those produced in <br />previous years for particular locations. <br />' New areas mined in 1987 were ;getter over a larger area than 1986, but no.^.e `_'^~ <br />less produced small flows. The flaws were not measurable. Roof drippers, wet <br />1 <br />