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08/8/00 <br />SANITARY FACILITIES <br />Fndnote -- SANITARY FACILLTLES <br />This report shows the degree and kind of soil limitations that affect septic tank absorption fields, sewage lagoons, <br />and sanitary landfills. The limitations ere considered "Slight" if soil properties end site features generally are <br />favorable for the indicated use and limitations are minor and easily overcome; "Moderate" if soil properties or site <br />features are not favorable for the indicated use and special planning, design, or maintenance is needed to overcome or <br />minimize the limitations; and "Severe" if soil properties ar site features are so unfavorable or so difficult to overcome <br />that special design, significant increases in construction costs, and possibly increased met ntenance are required. <br />This report also shows the suitability of the soils for use as daily rover for landfills. A rating of "Good" indicates <br />that soil properties and site features are favorable for the use and good performance and low maintenance can be <br />expected; "Fair" indicates that soil properties and site features are moderately favorable for the use and one or <br />more soil properties or site features make the soil less desirable then the soils rated "Good"; and "Poor" indicates <br />that one or more soil-properties or site features ere unfavorable for the use and overcoming the unfavorable <br />properties requires special design, extra maintenance, or costly alteration. <br />SEPTIC TANK ABSORPTION FIELDS are areas in wFii ch effluent from a septic tank is distributed into the soil through <br />subsurface tiles or perforated pipe. Only that part of the soil between depths of 24 to 72 inches is evaluated. The <br />ratings are base on soil properties, site features, and observed performance of the soils. Permeability, a high <br />water table, depth to bedrock or to a cemented pan, and flooding affect absorption of the effluent. Large stones <br />and bedrock or a cemented pan interfere with installation. Unsatisfactory performance of septic tank absorption fields, <br />including excessively slow absorption of effluent, surfacing of effluent, end hillside seepage, can effect public health. <br />Gr iwater tan be polluted if highly permeable send and gravel or fractured bedrock is less than 4 feet below the <br />baste of the absorption field, if slope is excessive, or if the water table is near the surface. There must be <br />unsaturated soil material beneath the absorption field to filter the effluent effectively. Many local ordinances <br />require that this material be of a certain thickness. <br />SEWAGE LAGOONS are shallow ponds constructed to hold sewage while aerobic bacteria decompose the solid end liquid <br />uestes. lagoons should have a nearly level floor surrourded by cut slopes or embankments of compacted soil. Lagoons <br />generally are designed to hold the sewage within a depth of 2 to 5 feet. Nearly impervious soil material for the lagoon <br />f Loor and sides is required to minimize seepage and contamination of ground water. This report gives ratings for <br />the natural soil that makes up the lagoon floor. The surface layer end, generally, 1 or 2 feet of soil material <br />below the surface layer are excavated to provide material for the embankments. The ratings are based on soil <br />properties, site features, end observed performance of .the soils. Considered in the ratings are slope, permeability, a <br />high water table, depth to bedrock or to a cemented pan, flooding, large stones, and content of organic matter. <br />Excessive seepage due to rapid permeability of the soil or a water table that is high enough to raise the level of sewage <br />in She lagoon causes a lagoon to function unsatisfactorily. Pollution results if seepage is excessive or if floodwater <br />overtops the lagoon. A high content of organic matter is detrimental to proper functioning of the lagoon because it <br />inhibits aerobic activity. Slope, bedrock, end cemented pans can cause construction problems, and large stones can <br />hinder compaction of the lagoon floor. <br />SANITARY LANDFILLS are areas where solid waste is disposed of by burying it in soil. There are two types of landfill, <br />trench and area. In a trench landfill, the waste is placed in a trench. It is spread, compacted, and covered daily <br />with a thin layer of soil excavated at the site. In an area landfill, the waste is placed in successive layers on the <br />surf ate of the soil. The waste is spread, compacted, end covered daily with a thin layer of soil form a source away <br />from the site. Both types of landfill must be able to beer heavy vehicular traffic. Both types involve a risk of <br />groundwater pollution. Ease of excavation and revegetation need to be considered. The ratings in this report ere based <br />