Agenda - Council - 11/25/1997 - Laserfiche WebLink

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Secvaage disposal *wtenis 1. Filter material for a soil treatment unit using gravity distribution of effluent shall not be placed in contact with original soils having a percolation rate faster than 0.1 minute per inch. 2. For coarse soils having a percolation rate faster than 0.1 minute per inch, at least 12 inches of loamy sand textured soil having a percolation rate between 6 and 15 minutes per inch at the original site shall be placed between the filter material and the coarse soil along the excavation bottom and sidewalls. The size of the -soil treatment system must be based on the required treatment area for a soil having a percolation rate of 16 to 30 minutes per inch as specified in Table II. 3. For soils with percolation rates between 0.1 and 5 minutes per inch, at least one of the following treatment techniques shall be used: a) Distribute the sewage tank effluent by pressure flow over the treatment area as specified in this chapter. b) Divide the total soil treatment area into at least four equal parts connected serially; or c) Provide at least 12 inches of loamy sand textured soil with a percolation rate between 6 and 15 minutes per inch in situ between the drainfield rock and the coarse soils. Trenches must be used with this liner system. The size of the soil treatment system must be based on the required treatment area for a soil having a percolation rate between 16 to 30 minutes per inch as specified in Table II. d. Mounds. Printed 12./26/90 1. Mounds may be constructed on soils having the site or soil conditions specified in §8.30.04 Subd. 7. 2. The soil percolation rate in all layers of the natural or fill soil to a depth of at least 24 inches below the sand shall be faster than 120 minutes per inch. 3. The allowable absorption area loading rate must be determined according to Table III by the percolation rate of the 12 inches of original or fill soil immediately under the sand layer. Page 255