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i <br /> Mr.Roger Doak <br /> Coal Ash Pilot Project Proposal <br /> June 26,2000 <br /> Page 4 <br /> lines. Although the pilot test would contain material (coal ash and bottom ash) at lower <br /> hydraulic conductivity than the surrounding material, the simulation was ran with an <br /> impermeable barrier or trench to represent a worst case scenario for modifying the <br /> groundwater flow. As shown on Figure I in Attachment C, the trench has little effect on the <br /> groundwater flow direction or gradient. <br /> Solutions provided by Harr(presented in Attachment C) indicate the change in gradient change <br /> across a ten-foot ash trench would be on the order of 0.003 feet. The volume of water passing <br /> through a 100 foot trench filled with ash, ten feet deep and fully saturated would be <br /> approximately I gallon per day. The amount of water that would pass underneath the 100 foot <br /> trench, assuming a ten fool column of native soil, would be in excess of 5,900 gallons per day. <br /> The calculations show that water will easily divert beneath and around the ash and will not <br /> affect cross or downgradient water availability. The volume of water that will pass through the <br /> ash is insignificant to the water that will bypass the ash and as such water quality should not <br /> be greatly affected. <br /> 2. Varra Companies is in the process of submitting an Industrial Storm Water permit for the <br /> referenced project. <br /> 3. Background water quality sampling has been performed on four occasions and the analytical <br /> results are summarized in Table 1. Laboratory data sheets are presented in Attachment D and <br /> in the analytical data submittal. A review of analytical data show results for analytical suites <br /> as recommended by Mr. Ken Neiswonger of CDPH&E. <br /> 4. Management of coal ash will initially entail adding water to the ash so that its volumetric water <br /> content is near 0.20. This will help to reduce fugitive ash emissions due to wind and placement. <br /> The ash will be brought to the site by 20 yard, covered, end dump trailers. The volume of ash <br /> proposed for the pilot project is 400 tons. The ash will be stockpiled on ground near the proposed <br /> trench and covered with plastic. It is anticipated that the ash will be placed in the trench the day of <br /> delivery. The placement of ash in the trench will not occur during high wind events. If needed the <br /> ash will be wetted prior to its placement in the trench. The ash will be handled by means of a front- <br /> end loader and placed in the trench concurrent with the digging of the trench. <br /> If it is determined that the placement has created an adverse environmental liability the coal ash <br /> will be excavated by means of a track hoe. The ash will be place in the immediate vicinity of <br /> the trench on plastic and allowed to dry. The ash will then be taken to an approved landfill for <br /> disposal as soon as the ash meets an acceptable moisture level. <br /> 5. Various data have been provided regarding the local geology. The surficial geology of the area <br /> as documented by Colton, 1978, varies between wind blown deposits of clay, silt and sand and <br /> sandy to gravelly alluvium, which are Holocene in age. Colluvium consisting of bouldery to <br /> pebbly sandy silt and clay may contain and interfinger with alluvium of various ages. The <br /> Pierre Shale underlies the unconsolidated alluvial deposits in this area. The depth to bedrock in <br /> this area as documented by field observation varies between 15 and 30 feet below ground <br /> surface. <br />