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1986 HYDROLOGIC REPORT January 1, 1986 thru December 31, 1986 C INTRODUCTION Blue Ribbon Coal Company started the year in temporary cessation and went into permanent cessation during the year. The Blue Ribbon Mine was sealed January 31, 1986 with double row solid cinderblock seals. The portals were backfilled for a minimum of 25' and a second seal was installed in July 1986. The portal bench and access road were backfilled, and the #1 Pond, the highway and mine scale sites and the lower stockpile area were regraded. To replace the #1 Pond during the reclamation, a smaller #5 Pond was installed. The dirt work for these phases of reclamation was completed in September 1986 and seeding and mulching was completed in December 1986. The sediment ponds and access to the ponds will be reclaimed when approved by Colorado Mined Land Reclamation Division. SURFACE WATER The winter of 85-86 was again a good year for snowfall. An estimated 31,100 acre-feet of water flowed past the mine in Hubbard Creek. Run-off in the spring was more gradual this year than the past several years. This slow melting combined with a wet spring caused massive land movement along the creek. The mass average conductivity between the upper and the lower Hubbard Creek sample locations rose from 129.1 to 131.3 µmhos/cm. The average pH on upper and lower Hubbard Creek remained constant at 8.1. The #1 Pond discharged through NPDES discharge point 001 C when the #5 Pond was completed. The discharge from Pond springs. There were minor amounts of surface runoff and into the #1 Pond. The total discharge from the pond was mass average conductivity for the pond discharge was 593 pH of 8.1. until July 11, 1986 #1 was primarily from under drain discharge 13.15 acre-feet. The µmhos/cm with an average Pond #4 discharged once in the spring as a wet spring snow melted rapidly. The #3 Pond had no discharge. Pond #5 was installed to eliminate the constant flow from springs that the #1 Pond had. Use of the pond started on July 11, 1986 and the first discharge was October 3, 1986. The primary source of water in the pond was the underdrains in the bench. The NPDES discharge point 001 is being transferred to this pond. The total discharge for this pond was 0.71 acre-feet. The mass average conduc- tivity for the discharge was 1614 umhos/cm with an average pH of 8.5. Due to the mine sealing and start of reclamation, the NPDES discharge point 004 had no flow. A revision to our discharge permit was requested to eliminate this point. The draw north of the mine was the only site monitored as a spring. Flow in this draw has continued to increase each year since first noted in the fall of 1984. The mass average conductivity of 1327 µmhos/cm is typical of ground water and is similar to discharge from the north underdrain. The average pH was 8.3. The total flow from the north draw was calculated to be 66 acre-feet.