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• 3. Even though chemicals will not be applied directly to the site after clay extraction is complete, agricultural chemicals could potentially be carried on to the borrow site along with surface water runoff from adjacent agricultural land. Dane County Public Works has discussed this possibility with Dane County Extension Soil Specialist Kevin Connors. He made the following points: - The quantity of nitrogen and/or herbicides and pesticides that could possibly move onto the borrow site due to surface water runoff and erosion of adjacent agricultural fields is extremely small compared to what is directly applied to agricultural fields. In addition, the soils that predominate in the uplands near the borrow site: Plano (PnB), St. Charles (ScB), Ringwood (RnB) and Rockton (RoC2) all have relatively high water holding capacities, and therefore, pose only a moderate threat of allowing contaminant laden surface water to run onto the proposed borrow area. - Consequently, a ditch and berm system designed to prevent surface water runoff from moving on the borrow site from adjacent field would not be worthwhile in this case. Because existing grassed filter strips would be bypassed, a ditch and berm system would likely increase runoff and erosion. 4. The Planning Commission is concerned about the size of the site. Less land would need to be disturbed if the County only used the northern portion of the site, which we previously approved back in 1989 (CUP 717). In addition, this portion of the site has the thickest clay and contains the bulk of the clay, and therefore, would be the most effective area from which clay could be extracted. Dane County Public Works has done calculations based on test pits and the Soil Conservation Service soil maps that show that the northern portion of the site contains approximately 126,000 cubic yards of clay on roughly 20 acres. The southern portion is larger (29 acres) so even with thinner clay deposits, the total amount of clay is approximately 139,000 cubic yards. It is important to note that the total number of acres that will be disturbed by clay extraction is roughly 50 acres not the entire 77 acres described in the CUP application. All of the steep, grassed and/or wooded hillsides will be left undisturbed. 5. When we previously approved the northern portion of this site back in 1989, one of the conditions on that CUP was that Dane County Public Works would back haul fill dirt from the landfill so that no sedimentation basin would be created. Why is the County unwilling to do the same now? In 1989, there was a surplus of fill dirt at the Rodefeld Landfill site. An expansion of the landfill has been approved, and this will require additional fill dirt as well as the additional clay that we are hereby seeking. Consequently, the landfill now has a negative soil balance and the County will need to have fill dirt hauled to the landfill for construction purposes. Therefore, to backfill the excavated areas at the proposed clay borrow site would necessitate the purchase and hauling of fill dirt to the borrow area which would make the proposed clay borrow project too expensive. However, in accordance with the Town of Cottage Grove Nonmetallic Mining Ordinance, the proposed sedimentation basin will not be a permanent pond. It will serve as a storm-water detention basin to prevent erosion and site runoff, and will become a dry basin between runoff events.