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Mr. Dennis W. Byrnes - 2 - January 28, 1988 Concern No. 3 - The Inactive Mines Program of MLRD has taken over respo~nsi6iT ty of the peat bog and drainage structures down to the North Thompson Creek. The Inactive (dine Program plans to construct a channel connecting from the outflow of the peat bog to the existing channel in 1988. The reason for the construction of the increased section of channel is to allow fora longer limestone rock contact with the mine drainage coming off the peat bog. The previously measured peak flow out of the peat bog has been 40 gallons per minute. The existing piping is sufficient to hold this flow. The construction of this channel will also minimize any potential erosion from discharge from the peat bog. The IMP will maintain responsibility for this channel . Concern No. 4 - Sediment pond P-9 was cleaned only during the reclamation process. No structures were modified. Therefore no recertification is required. Currently under Colorado regulations diversions are not required to have as built certifications. The Division has initiated a Rule change to correct this however, rock sizing has been verified in the field and slopes have been checked from the recently flown and remapped topography for the mine. Concern No. 5 - The proof of publication for the bond reduction and release wee -orwarded to the Albuquerque Field Office as soon as received. Concern IJo. 6 - No underdrain system was ever required for the refuse pile. e natura subdrain system is described on page 4-21, Vo]ume 1 of the Permit Application and further described in Appendix 4C. Concerning the recertification of the refuse pile sediment pond, in July, 1986 the Division approved a revision to the final reclamation contours for the refuse pile. This revision to the reclamation plan was required because the refuse pile never reached the expected volume or acreage originally proposed. The smaller acreage of refuse placed in the area will result in less sediment production and less runoff. A small amount of acreage from the Eastern edge of the mine site has been diverted into the refuse pile sediment pond to contain drainage. Due to the seeding and mulching of this area and the reclaimed refuse pile vegetation success, it is not believed that recertification or redesign of this pond needs to be undertaken. The original curve number the area was designed on was for bare refuse with greatly higher runoff than the existing mulched and revegetated areas. Also, the slopes of the existing reclamation are less than the slopes of the originally approved refuse pile. Therefore, the pond is adequate as originally designed for the maximum disturbance approved in the original permit application. Recertification was not required for this pond. Concern No. 7 - Soil sampling at the loadout by MLRD did include 8 core samp es eing taken. However, these were composited into 2 samples. The results of the sampling has been sent to the Albuquerque Field Office. Sampling at the mine site by the operator is also been forwarded to the Albuquerque Field Office.