PERMFILE69535 - Laserfiche WebLink

Home Browse Search

• MLRD Letter of Cecember 12, 1986; Comments & Responses !;i~f3 j j~987 ir`inrr~ ;...,~0 C~+cCUiMA710N DIVISION MLRD COMMENT: Our staff has reviewed the above referenced report prepared by 4Jater Engineering and Technology, Incorporated. At the outset, we find it is important to stress that there are two distinct issues which are of concern. The first is that in a number of areas the reclaimed topography diverges significantly from the original topography. Due to the Swale at the top of the slope in area 9/10 and the oversteepened valley bottom segments that occur in several locations, we find that grading has not been conducted so as to "... approximate the general nature of the premining topography identified in 2.10.3(1)(j)". further, a number of the valley bottom segments violate the requirement that "The final graded slopes shall not exceed in grade either the approximate premining slopes, or any lesser slopes approved by the Division ...". n U The general conclusion of the report appears to be that, with a few exceptions the regraded area has little variance from the approved postmine topography and therefore approximate original contour (ADC) has been achieved. We find that in a number of locations the topography has diverged from the original topography to such an extent that AOC has not been met and could not be met without substantial regrading. RESPO^ISE: Although the above comment does not address specific technical issues it does present the Division's position on interpretating AOC compliance. The Division has chosen to look at isolated areas on the mine site as opposed to viewing the entire mine in their compliance determination. CYCC believes it is justified to use the mine area for determining AOC compliance because it is comparable to a first-order drainage basin, which is the minimum area for geomorphic analysis. Furthermore, CYCC believes the legislative intent of the AOC