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site. If vegetative cover is unsatisfactory, soil analysis may be needed to determine if <br /> amendments are necessary for longterm vegetative productivity. <br /> The berm will be graded and the mine recontoured. The graded surfaces will be left rough, <br /> providing microtopography for soil and water retention. <br /> The old road on the south of the pit (800 ft.)was identified for closure and reclamation by 2007. <br /> From aerial photographs, the route still appears to be inadequately revegetated. The road should <br /> be field inspected for erosion and vegetation concerns. If needed, additional erosion control and <br /> seeding may be required. <br /> 5.6.1. Affected Environment <br /> The existing pit is located in an upland area within the North Platte River Basin. There are no <br /> nearby surface waters and any runoff from the permit area would be intercepted by irrigation <br /> ditches and livestock ponds. It is unlikely that any runoff from the permit area would reach <br /> perennial water. <br /> The pit is located on the top of a"mesa" or "terrace", and is above any know groundwater <br /> occurrences. The pit is not in contact with the water table or any seasonal groundwater. The mesa <br /> acts as a local groundwater recharge zone, with precipitation permeating down through the <br /> gravel until reaching an impermeable layer and travelling along the layer. The geologic <br /> formations in the area are dipping to the south/southwest, which is the direction of groundwater <br /> travel. Groundwater uses within a mile of the pit include BLM's Road Gulch Spring, Box <br /> Spring, Victor Spring, and Dry Fork spring. Road Gulch Spring (the closest source) is about <br /> 2,620 feet southeast of the pit's perimeter, and is approximately 260 feet lower that the pit. <br /> 5.6.2. Environmental Consequences — Proposed Action <br /> Due to the high infiltration and permeability rates of sand and gravel areas, it is important that <br /> refueling is not done in the bottom of the pit, and all chemicals or fuels on the site are stored in <br /> one designated area within the mine area. Any spill or contaminated soil would need to be <br /> reported and remedied as soon as possible, as it is much more difficult to remediate once a <br /> contaminant is transported below the soil surface. The depth to groundwater helps lessen the <br /> possibility of contamination from a spill. <br /> The Mine Plan limits the depth to be mined to 20 feet. Although it does not appear that any <br /> groundwater uses would be affected down gradient from the gravel pit, this depth should leave a <br /> sufficient layer of gravel remaining to continue to act as a recharge zone. The potential storage <br /> volume by the gravel will be reduced, but the connectivity for water movement would be intact. <br /> The large berm surrounding the pit area helps reduce wind and water erosion. Interim <br /> reclamation and stockpiles are monitored for accelerated erosion, which could have local <br /> DOI-BLM-CO-N020-2017-0003 27 <br />