Agenda - Council - 05/13/2014 - Laserfiche WebLink

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7080.2220 INDIVIDUAL SUBSURFACE SEWAGE TREATMENT SYSTEMS 50 Subp. 2. Location of mounds. A. The upper 12 inches of the original soil mound absorption area must have a mound absorption ratio of greater than zero under part 7080.2150, subpart 3, item E, Table IX or IXa. The upper 12 inches of the absorption area must also be above the periodically saturated soil or bedrock. B. Setbacks must be according to Table VII in part 7080.2150, subpart 2, item F. Setbacks must be measured from the original soil absorption area. C. On slopes of one percent or greater and where the original soil mound absorption ratio is 5.0 or greater in Table IX or 1Xa in part 7080.2150, subpart 3, item E, mounds must not be located where the ground surface contour lines that lie directly below the long axis of the distribution media bed represent a swale or draw, unless the contour lines have a radius of curvature greater than 100 feet. Mounds must never be located in swales or draws where the radius of curvature of the contour lines is less than 50 feet. Subp. 3. Mound design and construction. A. The mound distribution media bed area consists of bottom area only and must be calculated by dividing the design flow by 1.2 gallons per square foot per day. B. Mound distribution media beds must be determined according to part 7080.2150, subpart 3, item M, and must be no wider than ten feet. C. Clean sand must be used to elevate the mound distribution media bed and must consist of sound, durable material that conforms to the following requirements: Sieve Size No. 4 No. 8 No. 10 No. 40 No. 60 No. 200 Percent Passing 95-100 80-100 0-100 0-100 0-40 0-5 Clean sand must also contain less than three percent deleterious substances and be free of organic impurities. D. The original soil mound absorption area is determined by multiplying the original soil mound absorption length by the original soil mound absorption width. The original soil mound absorption width is calculated by multiplying the mound distribution media bed width by the mound absorption ratio. The mound absorption ratio of the upper 12 inches of soil in the proposed original soil mound absorption area shall be determined according to Table IX or IXa in part 7080.2150, subpart 3, item E. E. The required original soil absorption width for mounds constructed on slopes from zero to one percent must be centered under the mound distribution media bed width. The required original mound soil absorption width constructed on slopes greater than one percent must be measured downslope from the upslope edge of the mound distribution media bed width and measured in the direction of the original land slope and perpendicular to the original contours. Copyright ©2014 by the Rev so of Statutes, State of Minnesota. All Rights Reserved.