2008-04-10_REVISION - C1981010 - Laserfiche WebLink

Home Browse Search

'~ ~- Ms. Janet Binns, CDMG Re: PR OS Permit Revision Page 2 Landslide Reclamation Costs Backfilling and grading costs totaling $519,120 for task 1 above are included in the revised reclamation cost estimate (RCE) provided by the Division in the Adequacy Concerns letter of December 19, 2007. This item is shown as CIRCES Task #130. Also worth noting is the fact that backfilling and grading costs for G dip pit are duplicated in CIRCES Task #107 with a value of $627,699. This amount should be deleted. The cost of backfilling and grading the canyon areas to the south of the slide area (task 2) have been calculated and totals $263,811. Backup is shown in the attached Appendix A addition. The costs of backfilling in tasks 1 and 2 include the establishment of a drainage (task 3). Task 4, grade and seal the slide area, involves 484 hours of D l OR dozer time to seal any cracks and conduct final grading in areas outside the GD02 cut, canyon and bulge areas. The cost of this task is $130,762. The hours were developed assuming 387,200 cubic yards would be moved at a production rate of 800 lcy/hour. The production rate assumes an average 200 ft push with a 0.80 correction factor. The volume was determined by determining the total amount of material in the 240 acre slide area assuming a one foot average excavation depth. Some areas would be more, others less. Task 5, grade the bulge at the tce of the slide area, includes 40 hours of Dl 1R time to shape and seal the slide. toe bulge. The cost of this task is $14,700. Task 6, replacement of topsoil, assumes that topsoil would be replaced on all of the slide affected area that is not already covered in the current bond. A total of 82.7 acres of the 267 acre total is already covered in the G pit topsoil numbers shown in the Division's RCE. That leaves 184.3 acres unaccounted for. While some of this acreage is covered with undisturbed topsoil, this cost assumes that the entire 184.3 acres would require re- topsoiling. Atotal of 334,504 cubic yards was assumed using a 13.5" replacement depth (12" plus a 12.5% settling factor). Using the $1.353 cost per yard from CIRCES Task #180 results in a topsoil replacement cost of $452,584. Task 7, revegetation, uses the unit cost per acre ($524.89) from CIRCES task #123 and applies it to the 184.3 acres of topsoil replacement. In addition, a 20% failure rate is applied. The total revegetation cost is $116,000. The total landslide reclamation cost is summarized below: Task Cost 1 -Backfill GD02 $ 519,120 2, 3 -Backfill small south canyons $ 263,811 4 -Grade and seal slide area $ 130,762 5 -Grade toe bulge $ 14,700 6 -Topsoil replacement $ 452,584 7 - Reve e~ $ 116,000 Total $1,496,977 Comments included in Division RCE Total new liability $ 977,857 less Task 1, already in RCE