1983-06-30 Septic System Design Report

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June 30, 1983 Specifications, L300 3ayside Job # 1962 Page 3 of 4 SOIL SURFACE PREPARATION The discharge ripe from the pump to the mound areas all be installed prior to soil surface preparation. The trench excavated to install the discharge pipe shall be-arefully backfilled and compacted to prevent seepage of effluent. Compaction shall be to not less than 95% of standard proctor density according to ASTMS D.6989 The total area selected for the mound, inclyding that under the dikes, shall be rou^hened in order to thoroughly break up any existing sod layers and to provide a suitable t,ansition zone between the original soil and the sand layer of tht mu;md. The area shall be rou_-hened only when the moisture content of the soil 8 inches below the surface is drier than the plastic limit. Plastic limit is the soil moisture content below which the soil may be manipulated for purposes of installing a soil treatment system, and above which manipulation will cause compaction and puddling. If a fragment of soil can easily be rolled into a wire 1/8 inch in diameter, the moisture content is above the plastic limit. If the soil is dry enough to be friable and falls apart when rolling it into a wire, the moisture content is below the limit, and soil may be manipulated. The standard method of determining the plastic limit is specified in ;.merican Association of State Highway and Transportation Officials (A1.77'TO) Designations T 90-61. Surface preparation or roiir-hering may be rerformed Frith a mold board plow, a disk plo;•r, or backhoe using only the teeth. :tld board plow furroughs shall be at least 8 inches deep, stall be thro,m upslope and shall run perpdnc?icular to the slope. There shall be no dead furrow under the round. 3a^.khoe teeth nay be used to roughen the soil surface and break up the sod layer. Care mist be taken so as not to compact or puddle deeper soil layers. In no case stall any surface soil be excavated and removed from the area. I•'.ound constructi-n sY.all proce�,' irr:ediately after s•.:rface preparation is coxoletpr% L1•er7 effort sl;orld b� taken to prevent rain from falling or the rrer. ad soil surfaces. PLACr.'G S'.NM LAi"J'F.e k crawler tractor frith a blade or bucket shall be used to move the sand into place. At least 6 inches of sand shall be kept under the tracks to :.i ;r°ize compaction of the ploi-rec: layer. The sand layer rpon t!-,c filter material i- ^laced shall be level. OT! r a CC?1SID-.?.;,T-i `N, s e builder should coordinate the site de-.elornent so that the well is at least 50 feet from the septic tanks and treatment areal ar.d at least 100 feet from the treatment area :.f the well is less than 50 feet deep. ",ie suggest the well be placed in t-e general area sro::r or. Vic: site e.aluaticn location plan attached. It is recor-:erded that the b _ld.^rfence off the treat -gent area and n-) L2101-7 storzg_ of const~v^ti-n :T.at%rials or traffic on this area. TOM SMITH ASSOCIATES Inc