Laserfiche WebLink
Colony Reclamation Cost Estimate, Update to Exhibit L Rev. Sept. 2023 <br /> In addition to the more rational method for developing unit costs for the 2017 submittal <br /> described above, operator ExxonMobil had applied for and was approved for a major reduction <br /> of affected acreage in 2007. <br /> It was the combination of the above two items that resulted in the 2017 approved reduction from <br /> $30M to $9.5M. <br /> That 2017 bond reduction is summarized below to set the stage for this 2023 reclamation cost <br /> update. The affected acreage totals and the cost estimating methodology used in the 2007 <br /> bond reduction calculation have been used to develop this current reclamation cost estimate. <br /> While there are additional areas of affected acreage that might now be considered for release, <br /> as discussed herein in context of specific areas on site, such possible future reductions in <br /> affected acreage were not considered in this review. A further reduction in reclamation liability <br /> may be warranted if Colony's owners choose to proceed with future requests for release of <br /> those areas. <br /> Overview of 2007 Area Reduction Request <br /> Pursuant to an application submitted by then operator ExxonMobil in late 2006, and following an <br /> inspection that summer by CDRMS, the agency approved on Sept 5, 2007 an large reduction of <br /> 53% of the 1982 affected acreage. The areas were either removed from the permit due to land <br /> use change or were deemed to be in its permanent reclaimed form. <br /> Approximately half of the 1,131 total affected acreage as of January 2007 were released due to <br /> land use changes. These "land use change" areas included essentially all 186 acres of the <br /> "Parachute Properties. The Parachute (shipping)Terminal site, the river water intake site, and a <br /> 1982 construction laydown yard known as "Mahaffey Ranch" were deleted from the active <br /> permit area due to land use changes. In addition, the 42 acres of the Colony Access Road and <br /> side slopes on Unocal lands south of Colony's property line were deemed complete and in final <br /> form in 2007. <br /> Finally, within the actual mine property, generally described as the approximately 5700 acre <br /> "Resource Block in all but 527 acres of the 945 acres of affected area within that block were <br /> also deemed as completed reclamation and in their final permanent form in 2007. This included <br /> many acres of roadway side slopes in either rock cut or rockfill as well as the gravel surfaces <br /> that are now permanent roads. All of the Middle Fork dam disturbance including the dam and <br /> reservoir were deemed to be in their approved final condition. <br /> The remaining 527 acres of active affected acreage that were not released in 2007 mainly <br /> consists of <br /> • buildings and shops in the lower valley <br /> • the plant site and a large construction laydown area known as the LaSal Laydown Area, <br /> • all of the Coarse Ore Valley, <br /> • the Davis Gulch dam and reservoir and bedrock slopes immediately downstream, <br /> • a rockfill storage area above Davis Gulch Dam, <br /> • the 31 acres of the flat Mine Bench surface and its "A Groove Road" above the portals, <br /> • a small six acre ridgetop construction laydown site called "Summit Ridge" <br /> • a 4 acre construction water pipeline form Upper Davis Gulch to the plant site, <br /> • and several small to very large topsoil stockpiles. <br /> Page 2 <br />