REP22737 - Laserfiche WebLink

Home Browse Search

Annual Hyr'.rology Report April 22, 1988 Page 22 spring runoff, Dewatering procedures take usually less than one day with the exception of NID-5 which is responsive to a high spring groundwater table and sometimes has to be dewatered more often. Ponds P'IB-3 and NB-4 have not discharged during 1987 and recrords indicate they have not discharged since they were constructed. MB-4 sometimes catches hydraulic oil spills from the Unit Train Loadout and is pumped by a licensed contract hauler or the WE1CC vacuum truck which deposits the oil in the shop waste oil tank which is in turn pumped by a licensed waste oil recycling firm. This is a standazd procedure. i Flowmeters have been installed on all discharge points from sediment ponds which discharge intermittently to continuously recrord flows. The Quarterly Hydrology Reports contain information on flows, sampling points, and quality of water discharge from the mine site sediment ponds in 1986. All water dischazged was in compliance with NPDES permit effluent limitations. During spring runoff conditions as well as some precipitation events quality of water in the North Fork of the Gunnison is much horse than the quality of discharges from F1ECC sediment ponds and well outside NPDES effluent limitations. During winter baseflow and summer conditions water quality in the North Fork is better and is within NPDFS effluent limitations, however, this is the time of year when WFXC's ponds are rarely discharged. Flow amounts from WE~OC sediment ponds are low in comparison to the North ' Fork of the Gunnison flows. Ewen during low flow conditions on the North Fork F7EOC discharges represent an imperceptible difference in stream quality. ' It is apparent from the analyses that sediment pond discharges have had no adverse impact on the North Fork of the Gunnison River. The quality of discharges usually exceeds the quality of the North fork; and discharge ' flows are so small that incremental changes in croncentrations in the North Fork are imperceptible. ' Discharges of surface runoff is 1987 are expected to be similar to 1986.