HYDRO25625 - Laserfiche WebLink

Home Browse Search

COLORADO DEPARTMENT OF HEA~rH O Water Quality Control Division Rationale - Page 3 Permit No. CO-0027154 FACILITY DESCRIPTION: Outfall 005 (Continued) Pond D also treats three other sources. Overflow from a waste rock pit (area 2 pit), surface runoff from the tipple haul road and water draining from the surface into the portals of the mine. Thin is pumped from a point different from which the mine water itself is pumped. The permittee has conducted a study to determine the various contributions of pollutants from each source to Pond D. This study has shown that the area 2 pit overflow water quality is as significant as the mine drainage. This source is believed.to contain epoila contaminated water which emanates upgradient. Continuous flows are occurring from outfall 005. As shown in Appendix B, flows are steadily increasing. CYCC predicts flows of 1600 gpm (2.3 MGD) by the fourth year the underground mine is in operation. Pond D has a total capacity of 51 acre-feet (16.6 MG) below the emergency spillway. A total of 30.3 acre-feet (9.9 tom) of storage is needed for surface runoff (6.7 acre-feet for runoff and 23.6 acre-feet for sediment storage). Thus, 20.7 acre-feet (6.7 Imo) is available in the pond for treatment of other sources. Outfall 007 Outfall 007 is primarily comprised of groundwater from a spring which flows through the backfilled spoils of the reclaimed Area 1 Miae Pit. Surface runoff from the adjacent active mining area also may be discharged Pond F serves to treat both sources. The pond presently is undersized. CYCC is applying to MLRD for a technical revision to enlarge the pond. They expect to have the pond enlarged by March 15, 1986, in time for the next spring runoff. Discharge from the spoils area was first detected after the 1984 runoff season. Flow has been virtually constant since that time. Analyses have shown that the flow contains constituents similar to those found in mine drainage. A summary of four samples is found in Appendix C to this rationale. MONITORING SUMMARY AND OPERATING HISTORY: Discharge Monitoring Reports (DMR) Since 1981, numerous total suspended solids (TSS) and total iron (T. Fe) limitation exceedences have occurred from outfalls from surface runoff ponds. Most exceedences were the result of precipitation and thus exempt from the limitations per old federal guidelines. DMR's were last filed in 1982 for outfalls 009-013 and 015-017 because those outfalls were inactivated in March, 1983. As stated before, the discharge of mine drainage through outfall 005 began in March, 1984. Permit violations were reported for this outfall each quarter ezcept one. The permittee has met with the division about the violations and has performed a recent study to determine an appropriate solution.