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Effective April 28, 2015 Chapter Four Subsurface Sewage Treatment System Regulations 9.5 Soil observations. Complete soil testing on each individual lot must be conducted prior to permit issuance independent of any prior subdivision or lot approval testing. For permit issuance, a minimum of four (4) soil observations encompassing the proposed sewage treatment area are required. At least one soil observation must be performed in the portion of the soil treatment area anticipated to have the most limiting conditions. Larger areas may be required where conditions of use, soils, topography, or vegetation require. Soil observations must comply with the following requirements: (1) The soil observation must be conducted within or on the borders of the proposed site; (2) The soil observations must be performed in an exposed pit or by hand augering or probing. The use of flight augers is not allowed; (3) The soil observation method must allow observation of the different soil horizons that constitute the soil profile and, if determining the loading rate by use of Table VI an undisturbed soil sample must be observed; (4) Underground utilities must be located before soil observations are undertaken; (5) Required safety precautions must be taken before entering soil pits; (6) Soil observations must be conducted prior to any required percolation tests to determine whether the soils are suitable to warrant percolation tests and, if suitable, at what depth percolation tests shall be conducted; and (7) The minimum depth of the soil observations must be to the periodically saturated layer, to the bedrock, or three feet below the proposed depth of the system, whichever is less. 9.6 Soil descriptions for determination of limiting layers. Each soil profile observed at the proposed soil treatment and dispersal area must be evaluated under adequate light conditions with the soil in a moist unfrozen state for the characteristics in items (1) through (8): (1) The depth of each soil horizon measured from the ground surface. Soil horizons are differentiated by changes in texture, color, redoximorphic features, bedrock, structure, consistence, and any other characteristics that affects water movement or treatment of effluent; (2) A description of all soil colors for each horizon according to the Munsell Soil Color Charts, Revised Edition, Munsell Color Corporation (1992), or equivalent. The color charts are incorporated by reference, are available through the Minitex interlibrary loan system, and are not subject to frequent change; (3) A description of the soil texture, and structure 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 Section 2.2 (46); (4) Depth to bedrock. (5) Depth to periodically saturated soil for new construction or replacement as determined by redoximorphic features and other indicators, as determined in subitems (A) to (C): (A) In subsoil and parent material, redoximorphic features include: i. Distinct redoximorphic iron accumulation or distinct redoximorphic iron depletions; ii. A gleyed or depleted soil matrix or redoximorphic mottles having a color chroma of two or less or a depleted matrix or redoximorphic mottles having a color hue of 5Y and a chroma of three or less; or iii. Faint redoximorphic concentrations or faint redoximorphic depletions in subsoil or parent material with a hue of 7.5YR or redder. (B) In lower topsoil layers that are deeper than 12 inches from the surface and are immediately followed in depth by a periodically saturated horizon, redoximorphic features include: i. Soil colors with a redoximorphic chroma of two or less; or ii. Redoximorphic accumulations or depletions. (C) In the upper 12 inches of the topsoil layer, if it is immediately followed by a periodically saturated horizon, the depth of seasonal saturation is determined by one or more of the indicators in units (i) to (vi): i. Soil colors with a chroma of zero; 35 Washington County Development Code