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

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7080.1720 INDIVIDUAL SUBSURFACE SEWAGE TREATMENT SYSTEMS 26 (c) dominance of hydrophytic vegetation; (d) the soil treatment area at or near the elevation of the ordinary high water level of a surface water or in a concave hill slope position; (e) redoximorphic accumulation or depletions; or (f) the soil expressing indicators of seasonal saturation as determined in Field Indicators of Hydric Soils in the United States: A Guide for Identifying and Delineating Hydric Soils, USDA Natural Resource Conservation Service (2006 and as subsequently amended). The field indicators are incorporated by reference, are available through the Minitex interlibrary loan system, and are subject to frequent change; F. depth to the periodically saturated soil for all existing systems, determined by redoximorphic features in item E, except subitems (2), unit (a), and (3), units (a), (c), and (d), as measured outside the area of system influence in an area of similar soil; G. depth of standing water in the soil observation excavation, measured from the soil surface, if observed; and H. any other soil characteristic that needs to be described to design a system, such as hardpans or restrictive layers. These other characteristics must be classified according to the Field Book for Describing and Sampling Soils, which is incorporated by reference under part 7080.1100, subpart 36. Subp. 6. Determination of loading rate and absorption area size. The effluent loading and absorption area size must be determined by item A or B, or both, as required by the local unit of government: A. the loading rate based on an examination of soil texture, undisturbed soil structure, and soil consistence at the depth of either the proposed soil absorption area or the most restrictive layer within three feet of the proposed soil absorption area, using the United States Department of Agriculture (USDA) soil classification system as specified in the Field Book for Describing and Sampling Soils, which is incorporated by reference under part 7080.1100, subpart 36; or B. the loading rate based on the percolation procedure described in subitems (1) to (8) or other equivalent procedure as approved by the local unit of government: (1) each test hole must be six to eight inches in diameter and have vertical sides. For mounds and at -grade systems, the bottom of each test hole must be in the upper 12 inches of the original soil. For trenches and seepage beds, the bottom of each test hole must be at the depth of either the proposed absorption area or the most restrictive layer within three feet of the proposed soil absorption layer; (2) soil texture descriptions for percolation test holes must note the depths from the ground surface where texture changes occur; (3) the bottom and sides of the hole must be carefully scratched to remove any smearing and to provide a natural soil surface into which water penetrates. The scarification must not result in the hole having a diameter of greater than eight inches; (4) all loose material must be removed from the bottom of the test hole and two inches of one-fourth to three -fourths inch gravel or clean sand must be added to protect the bottom from scouring; (5) the hole must be carefully filled with clear water to a minimum depth of 12 inches from the bottom of the test hole and maintained for no less than four hours for saturation to occur. The soil must then be allowed to swell for at least 16, but no more than 30, hours. In sandy soils, the saturation and Copyright ©2014 by the Rev so of Statutes, State of Minnesota. All Rights Reserved.