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REVISED SITE EVALUATION REPORT for Lot 1,Block 1, Kokesh Farm Sewage Treatment System P e 3 Disking may be used for surface prepazation as a substitute for mold board plowing in soils having percolation rates faster than 15 minutes per inch(sandy loam)in the top 8 inch depth. Back hce teeth ma.y be used to roughen the soil surface and break up the sod layer. Care must be taken so as not to compact or puddle deeper soil la.yers. In no case shall any surface soil be excavated and removed from the area. Mound Construction shall proceed immediately af}er surface preparation is completed. Every effort should be taken to prevent ra.in from falling on the prepared soil surface. CONSTRUCTION NiA'TRRTAi.4 A1Vn PROCED TRF�; DISTRT�LTTTnN OF�FFi�LTFNT• A minimum of 12 inches of soil defined as sand shall be placed where the filter material is to be located. A crawler tractor with a blade or bucket shall be used to move the sand into place. At least 6 inches of sa.nd shall be kept under the tracks to mmumze compacting of the plowed layer. The sand layer upon which the filter material is placed sha11 l�level. Sand is defined as a soil texture composed by weight of a least 25 percent of very coaxse and medium sand, varying in size from 2.0 to 0.25 mm, less than 50 percent of fine or very fine sand ranging in size between 0.25 and 0.05 mm, and no more that 10 percent of particles smaller that 0.05 mm. A minimum depth of 9 inches of filter material (rock) sha11 be placed on the sand layer prior to installing the distribution pipe. Filter material is defined as clean rock, crushed igneous rock or similar insoluble, durable and decay- resistant material free from dust,sand, silt or clay. The size shall range from 3/4 inch diameter to 2 'h inch diameter. PRESSURE DISTRIBiTTION: Ei�luent sha11 be distributed over the filter material by three 1 1/2 inch diameter perforated pipes under pressure 72.5 feet long. Perforation holes shall be 1/4 inch diameter drilled in a straight line along the length ofthe pipe. Hole spacing shall be 30 inches with 30 perforation per lateral. Holes shall be drilled straight into the pipe and not at an angle. A sharp drill shall be used and any buns in the inside of the pipe shall be removed. The perforated pipe laterals shall be installed level with the perforations downward. The perforated pipe laterals shall be connected to a 2 inch diameter rnanifold pipe and sha11 have their ends capped. The laterals sha11 be spaced 40 inches on center and at 20 inches from the edge of the filter material. �'he manifold pipe sha11 be connected to the supply pipe from the pump. The manifold shall be sloped toward the supply pipe from the pipe. Geo-Te�rtile material shall be placed over the filter material. Construction vehicles shall not be allowed on the filter material until backfill is placed.