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2. We agree that the slope under the mound is about 11.5% as your letter indica;.es. We have used a Lotus 123 spreadsheet which we created to calculate mound quanta*ies. This worksheet is based on assumptions for a co, ic:ial mound. In the unusual case of u double mouna ich was dictated on this site for reasons of very 1.,-'ted space, the worksheet is of little use in calculating mound dimensions but it --oes calculate pump details and rock bed areas and some other quantities correctly. We entered such data as was necessary for the spreadsheet to calculate those quantities that it could. The underlying slope was not one of these quantities so it was left as it was from the last calculated. We then proceeded to size the mound baf:.. on space available and then used a calculator to ctit basal area and other "custom" aspects of this deaig. In retrospect, it would ha � been helpful if we haJ crossed out tie portion of tae form that we didn't use to avoid causing you confusion and a written record of our check of basal area and mound dimensions would have also een helpful in that regard. We measure a "wetable interface" of 8L square feet wider our mound. The acceptance rate of the rock bed is 1.20 gallons per day per square foot and the acceptance rate of the 13mpi underlying �-).il is 0.79 gpd/ft . Dividing these rates yields 1.52 basal width ri,tio and multiplying that ratio tiro-s the rock coed area of. 380 square feet we obtain a required "wetable interface" of 577 square feet. This provide about 50% overdesign but because of possible variati in the percolation rates and steepness of some pc ,ons of the underlying rite we felt that it was not advisable to reduce the size of the iourd. 3. We used all percoiati-, test results for determination of the average percolation rate which were taken at a depth appropriate for that purpose. Such tests are to determine the acceptance rate of the sand s,,il interface and are taken at a depth of about a foot. Te. is 1, 3, and 5 were taken at 14 in.jhes and yielded rates of 21, 8, and 11 minutes per inch respectively which averaged result in a design rate of 13 mpi.