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Site Evaluation Report for Rydel Homes, Inc. Page 3 Otto Job No. 18-0464 October 5, 2018 9 West Division Street, Buffalo, MN 55313 • 763-682-4727 • Fax 763-682-3522 • www.ottoassociates.com CONSTRUCTION MATERIALS AND PROCEDURES: DISTRIBUTION OF EFFLUENT: 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 sand shall be kept under the tracks to minimize compacting of the plowed layer. The sand layer upon which the filter material is placed shall be level. Sand is defined as a soil texture composed by weight of at least 25 percent of very coarse and medium same, 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 than 10 percent of particles smaller than 0.05 mm. A minimum depth of 9 inches of filter material (rock) shall 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 ¾ inch diameter to 2½ inch diameter. PRESSURE DISTRIBUTION: In each bed, the effluent shall be distributed over the filter material by three 2 inch diameter perforated pipes under pressure 73 feet long. Perforation holes shall be ¼ inch diameter drilled in a straight line along the length of the pipe. Hole spacing shall be 36 inches with 25 perforations per lateral. Holes shall be drilled straight into the pipe and not at an angle. A sharp drill shall be used and any burrs 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 manifold pipe and shall have their ends capped. The laterals shall be spaced 36 inches on center and at 20 inches from the edge of the filter material. The manifold pipe shall be connected to the supply pipe from the pump. The manifold shall be sloped toward the supply pipe from the pipe. Geo-textile material shall be placed over the filter material. Construction vehicles shall not be allowed on the filter material until backfill is placed. Sandy loam soil shall be placed on the filter material to a depth of 12 inches in the center of the mound and to a depth of 6 inches at the sides. Six inches of topsoil shall be placed on the fill material over the entire area of the mound. A grass cover shall be established over the entire area of the mound. No shrubs shall be planted on the top of the mound. Shrubs may be placed at the foot and side slopes of the mound. The side slopes of the mound will be 3 feet horizontal to 1 foot vertical (3:1). The soil material at the toe of the dike should be slightly less permeable or somewhat tighter than the natural soil below the mound. This can be accomplished by selecting a finer soil or by compaction. Whenever mounds are located on slopes, a diversion shall be constructed immediately up slope from the mound to intercept and divert runoff.