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Soil Cover Work Plan, former Cullet Staging Area Pilkington North America, Inc. 500 East Louise Avenue, Lathrop, CA a ntea g ro u p Antea Group Project No. PILKCU3215 provide a suitable growing media for the erosion reducing plant cover resulting from the hydro -seed application. Once germination has occurred from the applied hydro -seed and root development progresses, the cover's resistance to erosion will continue to increase and the cover will become more stable. In place of a single layer of blended agricultural soil, a multi -layer engineered cover specifically designed to optimize isolation of the debris, maximize plant cover, reduce infiltration, and effectively control erosion with a thinner, more economical cover is proposed. The proposed engineered cover will consist of three layers; granular bentonite, blended agricultural soil, and hydro -seed. A 0.25-0.5 inch layer of granular bentonite clay, typically used in engineered landfills, is proposed to be placed on the former cullet staging area, overlain with six -inches of a blended agricultural soil, and then topped by a hydro -seed application of native grasses and clover. The bentonite, when hydrated, expands by 15 to 20 times the dry volume and would act as a barrier to water infiltration. Bentonite is volcanic -derived clay with very minimal water transmissivity on the scale of 1 centimeter times 10-6 per second (approx. 1 ft./year). The bentonite would also provide resistance to erosion and a more impervious barrier on top of the remaining cullet residue than soil alone. The blended agricultural soil, placed over the bentonite, would stabilize the bentonite during times of maximum hydration, and provide a layer of nutrient rich material to promote and sustain plant growth. The proposed layer of bentonite would reduce infiltration and provide the same erosion resistance as approximately six to eight inches of soil. The six inches of blended agricultural soil placed on top of the bentonite would provide the growing media for the plant cover providing the remaining erosion resistance. Once germination has occurred from the applied hydro -seed and root development progresses, the cover's resistance to erosion will continue to increase and the cover will become more stable. A minimal, six-inch cover would also be less prone to excessive erosion due to minimized differences in elevation. A licensed surveyor would be used with this approach to ensure that the cover is installed to the proper thickness. Several pieces of heavy machinery would be used to apply the bentonite and move the soil from the delivery trucks to the former cullet staging area, including but not limited to spreaders, scraper/excavators, dump trucks, front-end loaders, compactors, and bull dozers. 4.1 TIMING AND INSTALLATION OF THE COVER Upon approval of the final work plan by the SJCEHD, Antea Group will begin preparation for field activities, including submittal of permit applications and coordination with PNA contractors to obtain the appropriate materials for cover installation. Once the permits and materials have been received, PNA will commence field activities as outlined below. 4 www.anteagroup.com