REV09218 - Laserfiche WebLink

Home Browse Search

TRAPPER MINE RESPONSE TO PR-1 ADEQUACY RESPONSE DOCUMENT May, 1987 2. Topsoil In addition, based on the current topsoil salvage problems, the operator must verify the estimated strippng depths. Topsoil salvage depths at Trapper have been significantly different than those estimated by the baseline soils inventory. Therefore, Trapper must submit a material balance which shows that sufficient topsoil can be salvaged to implement the reclamation plan. In addition, the Division reserves the right to require Trapper to resample in order to verify the estimated stripping depths for the new area. Response Actual topsoil removal depths to-date differ from what was forecast by about two inches less. Stripping by scrapers is only accurate to + two inches. Thus, the error in predicted and actual is not really signifi- cant on a mine-wide basis. Further, the Soil Survey conducted at Trapper Mine was an Order One soil survey. An Order One soil survey is the most intensive soil survey con- ducted by the Soil Conservation Service and has historically been consid- ered adequate for soil inventory purposes in land use and agricultural planning. Another Order One soil survey would not improve on the estimates. Moreover, the major purpose of a soil survey prior to mining (as I under- stand) is to estimate the quantity of topsoil available and to determine if soils have adequate quality for the intended purpose. I believe that being within two inches of an estimate in terms of soils is entirely rea- sonable. Can the Division cite examples from other large surface mines where an Order One soil survey has been done and the actual soil depths stripped are less than + two inches from forecast? If so, how much less and what was forecast? Also, if the actual amount of material available is less than forecast, one must ask what could be the consequences to the proposed reclamation plan and bond. Generally, the bond moneys needed to reclaim would actually be less, cer- tainly no more since the bond is calculated on replacement of more yard- age than what may be actually available. (One would not expect the regu- latory agency to purchase soil off site but to use what is available). If insufficient topsoil was available at any point in time to reclaim a site (due to bond forfeiture) to the permitted replacement depths, then those land uses requiring a minimum depth would naturally receive prior- ity in terms of available topsoil resources. Again, in no event would the State go off the mine site to purchase additional topsoil. cont.