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~,. <br />it is unlikely that the amount of material thafcould contain 2,4-D in excess of 10 mg/Kg is more than <br />50 cubic yards. <br />Therefore, if any soils of this type are encountered, a small area of flat ground east of the asphalt <br />plant will be covered with 6 inches of compacted non-permeable clay. Subsequently, the soils above <br />0 mg/Kg 2,4-D will be placed on the clay to a thickness no greater than 8 inches to allow the soils to <br />naturally aerate. A berm of 1.5 feet height compacted clay will be placed around the entire perimeter <br />of the soil and clay base. The clay base and berm are included to prevent any contamination from <br />entering the soils, ground water and surface waters around the site. The size of the clay liner and <br />berm will be determined by the amount of soils above 10 mg/Kg encountered. If the amount were to <br />be 50 cubic yards, the size of the clay lined area needed would be 1800 square feet or an area 42.4 <br />feet x 42.4 feet, not counting the berm. A sketch of the proposed clay-lined area is enclosed as <br />Figure 2. <br />Due to the rapid breakdown of 2,4-D upon exposure to air, it is expected that levels in the segregated <br />material will fall to below the 10 mg/Kg limit within a few weeks. Sampling will be conducted at <br />every 600 square feet interval within the clay-lined area until all material is below this limit. The <br />samples will be sent to an accredited laboratory to test for 2,4-D. This will be done at two week <br />intervals until the levels drop below ] 0 mg/Kg for the entire clay-lined area. This will be determined <br />by laboratory analysis. Once this is achieved, the material will be hauled to the Eagle County <br />approved disposal facility. As previously mentioned, we believe that the chances of any significant <br />quantity of material being above the 10 mg/Kg limit are remote. <br />3) If any material is encountered which is below 0. ] mg/Kg concentration of 2,4-D, this material will <br />be allowed to remain on site with no treatment. B&B will not allow any of this material to enter the <br />kiln for asphalt production. It will simply be kept on site and allowed to naturally aerate. This <br />concentration level should not present any danger for contamination to ground water or surface water <br />since a) the compaction of the yard surface is very high and b) the known chemistry of the 2,4-D <br />shows significant adsorbtion in the gravel and soil materials and c) the levels the application rate for <br />2,4-D to be effective in weed control on surface soils is 2.0 mg/Kg. <br />6 <br />