REV02955 - Laserfiche WebLink

Home Browse Search

DELTA SAND AND GRAV~CO. a • PAGE 2 MLRB PERMIT # M~ti~f9= ivt, 9 ~ ' V (~' ADEQUACY RESPONSE June 12, 1996 The pond as it existed before mining was an "irrigation seepage pond," when mining began it was converted to a "fresh water pond" supplying water to the crusher and screen plant. Before mining this pond accumulated irrigation water runoff from the farming practices on the original 40 acres. As this area is taken out of production this pond will not be needed for that purpose, so it has been converted to a fresh water pond. You aze correct in your observation that the pond will be 30 feet lower as the gravel material under the pond is mined and the pond will be reconstructed on the floor of the mined area. When it is relocated it will be totally reconstructed, any existing vegetation, banks, trees, etc. will be removed. This is not considered waters of the U.S. because it is part of an irrigation structure and the surround vegetation has occurred because of the abundance of irrigation water. The vegetation that occurs azound the reconstructed pond will be consistent with the revegetation that takes place on the rest of the site. The interior slopes will be at least 3h to lv as required by the regulations. A stormwater management plan (SWMP) has not been prepared at this time. We do not anticipate any runoff from storms oceumng, because once the topsoil is removed rain and snow soaks into the gravel and there is no runoff. If this condition changes we will prepare a SWMP at that time. Drainage from the operation and return wash water is recycled thru settling ponds located near the plant. Any runoff from the disturbed area is retained on site and routed to the settling ponds to avoid water leaving the site. Exhibit - D Mining Plan The 25-foot setback noted in the submittal denotes the closest point the top of the slope will get to the permit line. The setback is used to store topsoil needed for reclamation and where temporary access roads are located around the site. We agree that it will be important to maintain a digline setback of 70 feet if the cudfill method of sloping is used. This will retain the 25-foot area and provide 45 feet to create the slope into the bottom of the mine. We do not expect to have more that 700 feet of neaz vertical face exposed at any time. This will be along the working face where active mining is taking place. The face will probably have 2 to 3 benches to reduce the highwall height, making the facility safer and easier to reclaim. The slopes on the perimeter of the site will be created shortly after mining has reached the outside limits of the mined azea. This is done to keep reclamation as concurrent with mining as possible and reduce the amount of cut/fill sloping necessary on the site. At the time when we did the original planning we included the western area in the permit so if we decided later to mine the azea we would not have to amend the permit a second time. After our discussion, I do not think we want to totally rule out mining the area in the future. This area accumulates water from an irrigation waste ditch, contains an earthen ditch, a road and an old mined area where, under current conditions, it is not practical to mine. If we can address all the problems on this site we may choose to mine it