Agenda - 10-17-2000-9e - Laserfiche WebLink

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,~ •. 5. ~~_a3-:•ta.._ ~F acs=__~=~~~ _.,.,~ ..... .- ...,:L3..aT_. ~33C~?.C33 CC)ISmR'IaT=C:I 33:21/_0 l:°/3/~0 SANITARY FACILITIES Endnote -- SANITARY FACILITIES This report shows the degree and kind of soil limitations that aiiect septic tank absorption fields, sewage lagoons, and sanitary landfills. The limitations are considered 'Slight" if soil properties and site features generally are favorable for the indicated use and limitaCioxls are minor and easily overcome; "Moderate" if soil properties or site features are not favorable far the indicated use and special planning, design, or maintenance is needed Co overcome or minimize the limitations; and "Severe" i# soil properties or site features are so unfavorable or eo difficult to overcome that special design, significant increases in construction costa, and possibly increased maintenance are required. This report also shows the suitability of Che sails for use as daily cover far landfills. A racing of "Good" indicates that soil properties and site features are Lavorable Lox the use and good performance and low maintenance can be expected; ^Fair• indicates that soil properties and site features are moderately Favorable for the use and one or more soil properties or site features make the soil less desirable than the soils rated "Good'; and "Poor" indicates that one or more soil properties or site features are unfavorable for Che use and overcoming Che unfavorable properties requires special design, extra maintenance, or costly alteration. SEPTIC TANK ABSORPTION FIELDS are arena in which effluent from a Septic tank is distributed iaCO Che 9011 through subsurface tiles or perforated pipe. only that part of the 9011 between depths of Z4 Co '72 fache• is evaluated. The ratings are base on soil properties, Site features, and observed performance of Che soils. Permiea6111Cy, a high water table, depth to bedrock Or to a cemented pan, and flooding affect absorption of the effluent. Large stones and bedrock or a cemented pas interfere with installation. I7nsatiafactoxy performance of Septic tank abaorpCioa fields, including excessively slog absorption of effluent, surfacing of effluent, and hillside seepage, can affect public health. Groundwater can be polluted if highly permeable sand sad gravel or fractured bedrock is less than 4 feet below the base of Che absorption field, iL slope is excessive, or if the racer table is near the surface. There must bn unsaturated soil material beneath the abaorpCioa Lield to filter Che effluent effectively. Many local ordinances require Chat Chia material be o! a certain thickness. SBwAGS LAGOONS are shallow ponds constructed to hold sewage while aerobic bacteria decompose the solid and liquid wastes. Lagoons should have a nearly level Llopr surrounded by out elopes or em~~.^~^CS o! Compacted soil. Lagoons generally ors designed to hold Che sewage within a depth of 2 to 5 feet. Nearly impervious soil material for Che lagoon floor and aides is required to mialmize seepage and contamination of ground water. This report gives ratings !or the natural soil that makes up the lagoon floor. The surface layer and, generally, l or ~ feet of soil material below the aurtace layer are excavated to provide material for the ember^~~^ta. The ratings are based oa soil properties, site features, and observed performance o! Che soils. Considered in the ratings are elope, permeability, a high water Cable, depth Co bCdrgCk oa CO a Caseated pas, flooding, large atones, and CoaCent of organic matter. Excessive seepage due to rapid permeability at the coil or a water table that is high enough to raise the level of sewage in the lagoon causes a lago~ rA fuactioa uxisatisfactorily. Pollution results if seepage is excee9lve or if floodwater overtops the lagoon. A high Cxadfeeat of organic matter ie deCximental to proper functioning of Che lagoon because it inhibits aerobic activity. S~ bedrock, axed Cemented pane can Cause construction problems, and large Stories Can hinder compaction of the lagooe !loos. SANITARY LANDFILLS are areas where solid waste ie disposed of by burying it in agil. There are two types o! landfill, trench and area. In a trench landfill, the waste is placed in a trench. It is spread, compacted, and Covered daily with a thin layer of soil excavated aC Che 91.te. In an area landfill, the waste ie planed in aucceseive layers on Che surface of Che .soil. The waste is spread, compacted, and covered daily with a thin layer o! soil form a source away Erom the site. Both types of landfill moat be able to bear heavy vehicular Craffie. Hoch types imrolve a risk of groundwater pollution. Ease of excavation and revegeCaCioa need to be considered. The ratings iii Chia report axe based