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(Page 2) <br />MINE ZD # OR PROSPECTING ID # M-1977-436 <br />INSPECTION DATE 11/09/01 <br />INSPECTOR'S INITIALS ESC <br />This was an inspection of the Brighton Mine conducted by Erica Crosby of the Colorado <br />Division of Minerals & Geology. Connie Davis of Aggregate Resources, Inc. was present during <br />the inspection. <br />The Brighton Mine was inspected in conjunction with the bond release inspection of the <br />Aggregate Resources Pit, Permit No. M-1982-148. The Aggregate Resources Pit was incorporated <br />into the Brighton Mine in an amendment approved by the Division on November 6, 2000. The <br />Aggregate Resources Pit was permitted for a total of 69.7 acres with a financial warranty in <br />the amount of $17,800.00. The released area is in the middle of the Brighton Mine, and is <br />currently being used as a tree nursery. Only a small excavation was constructed on the site, <br />and is now being used as a detention pond. <br />The Brighton Mine is divided into two distinct areas, the North Lake and the Central <br />P,e servoir. A previous operator (Hammer) mined the North Lake. Mining is complete in this <br />area, and is currently being reclaimed to a wetland area. The operator stated that pit slopes <br />will be reduced to accommodate the constructed wetlands in accordance with Adams County and <br />Urban Drainage. The operator has dewatered the north pit to accommodate reclamation. The <br />pit is approximately 65 feet from the South Platte River. River water seeping into the pit <br />has created instability in the pit slopes in terms of slumps and slides. The approved permit <br />states that the north pit will be reclaimed to a groundwater lake with slopes no steeper than <br />3h:ly. It also appears that dewatering was not approved for the northern pit area. <br />instability of the pit slopes adjacent [o the River and dewatering the pit are two problems <br />that need to be addressed by the operator. In particular, the operator will need to address <br />the configuration of the pit slopes to ensure that the South Platte River does not breech <br />into the pit. The operator will need to address mitigation of the north pit slopes as a <br />technical revision to the permit. In addition, the operator will need to address impacts to <br />the hydrologic balance as a result of the dewatering operation. See page 3 for further <br />information. <br />Mining is currently taking place in the southern portion of the pit. The pit is being dry <br />mined, and mine water is pumped into a sump and eventually into the South Platte River. Pit <br />run material is transported on a conveyor to the screening facility. The pit will be lined <br />with a slurrywall along a majority of the pit and a compacted clay liner on a narrow portion <br />adjacent to the South Platte River. Topsoil piles were observed, and old piles are covered <br />with annual weeds. The operator should be reminded that topsoil piles stored in place for <br />longer than one year will need to be stabilized with a temporary seed mixture. <br />The Division holds a bond in the amount of $1,579,215.00. This amount appears to be <br />sufficient for the costs associated with reclamation of the site. <br />I ~ E Contact Address <br />^ CE <br />NAME Connie Davis _', BL <br />OPERATOR Aggregate Industries ^ FS <br />STREET P.O. Box 3121 ;] HW <br />CITY/STATE/ZIP Greeley, Colorado 80633 ^ HMWMD (CH) <br /> SE <br />rJ~J `~ ` yOL70 ~~i ~'O [~DO~ ~//'S~ ~yZ ~oZ w4cD (CH) <br />cc: Carl Mount; DMG <br />