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Earthmoving Operations (Soil & Overburden Salvaael: <br />As a new area is opened for gravel extraction the topsoil is pushed aside, typically with a <br />bulldozer. As a result topsoil stockpiling occurs around the perimeter of the mining area. <br />This facilitates the replacement of topsoil over the regraded area by simply using the <br />bulldozer to push the topsoil on to the newly established slopes. <br />The sandy to gravely soil is removed to its full depth as indicated by a color change. The <br />depth of salvage averages about 8", but can be as much as 12" to 14" in some places. The <br />color change usually indicates the point where the upper, more organic material meets the <br />subsoil. Because the soils covering the gravel are poorly developed (see soil information) <br />there is little concern about sepazating A horizons from B horizons. The B horizon is not <br />usually present in this azea. The soils on this site developed from the gravel deposit <br />through biological action and therefore, except for the organic component, the subsoil has <br />little physical differentiation from the upper organic layers. <br />Overburden, in the true sense of the word, is not usually encountered. Essentially the soil <br />is the overburden. Once the soil has been removed, inmost cases, the gravel deposits are <br />fully exposed and ready for mining. <br />Drainage Control: The mining plan map and the reclamation map, when combined, show <br />the pit will drain in two directions. In the earlier stages the pit will drain towazd the <br />intersection of Garrett and Cutis roads as it has done throughout the history of the site up <br />to this point. <br />Sediment control is accomplished within the pit. Through the use of gradual slopes in the <br />pit bottom as well as shallow depressions the rate of flow is reduced allowing nearly all <br />sediment to settle out prior to the water leaving the pit. The bottom of the pit will have a <br />very gradual slope (1% to 2%) over a considerable distance allowing for sediment control <br />while still permitting water to leave the site quickly in order to reduce to potential for <br />ponding. <br />Area Worked at Any One Time: As a result of the intermittent nature of the operation <br />and the relatively ]ow production volume it is difficult to identify a discrete amount of <br />land that is operated at any on time. A particular working face maybe exposed for years <br />with change in the actual area operated increasing by only a few thousand square feet. <br />On the other hand, during periods of heavier activity it would not be unusual to see one or <br />two acres of material removed. This operation has been in place for approximately 34 <br />years and the total disturbance is only 35 acres. <br />Rather than indicating an area worked at any one time, the disturbance category <br />differentiation is utilized to describe how the operation proceeds and how the mining will <br />