REP35632 - Laserfiche WebLink

Home Browse Search

' Annual Hydrology Report April 28, 1988 Page 8 1.4 Mine Water bbnitoring ' Mine inflows in areas being actively mined were mapped on an ongoing basis in water year 1987. Areas of previous mine inflows were monitored by occassional visits and by sampling of flow and quality during dewatering operations. Exhibit II shows locations and estimated amounts of mine inflows as well as sa•[ipling locations. Inflows into previously mined areas along Sylvester Gulch and near the main t portals continued to be highly responsive to the spring runoff season. Exhibit II shows' estimated average flows for the spring runoff season and the low flow time of yeaz, as well as hydrologic conditions which were encountered in areas ' mined during water year 1987. Inflows appeared to be about the same as in 1986 for areas around Sylvester ' Gulch. Nbre effort was spent in 1987 to dewater the inflows near the Sylvester Gulch Fan. Resultantly, a much higher discharge amount is listed for the NPDES point 011. 4he dewatering effort was undertaken to try to prevent additional floor heave in the area, due to water saturation, and to improve ventilation by ' decreasing standing water. The discharge from the mine portal azeas was approximately the same as 1986. i ' Areas along Sylvester Gulch Main Mine Fan entries produced measured flows ranging from 2 GPM during low flow oanditions, to 6 GPP9 during spring runoff conditions, and 3 GPM during low flow conditions to 9 GPM during spring runoff conditions, for twv locations which were checked. See Exhibit II for locations of flow measurements. Areas of standing water were also mapped and are shown on Exhibit II. ' The old Sylvester Gulch area (entries 14 through 21, main intakes) produced estimated flows ranging from 0 GPM during low flow conditions to 1 GPM during ' spring runoff conditions. Exhibit II shows the location of this flow measurement. The main portal area (entries 1 through 5) had estimated flows ranging from 0 to ' 0.25 GPM during low flow condition and 1 to 3 GPM during spring runoff conditions. ' Entry O1 and 1 on the east side of the main intake from crosscut 1 to crosscut 7 had standing water year round and flows were estimated at 0.0 to 0.5 GPM during low flow conditions and 2 to 5 GPM during spring runoff. 1 1 I Entry 8 and 9 on the west side of the southwest main intakes from portal entry 5 to crosscut 7 produced floras estimated at 0 to 0.25 GPM during low flow conditions and 0.5 to 1.0 GPM during spring runoff conditions. 'These flows are similar in both quality and quantity to those produced in previous years for particular locations. New areas mined in 1987 were •;e`ter ever a larger area than 1986, but ro.^.e :''° less produced small flows. The flows were not measurable. Roof drippers, wet