1985-12-17 Septic System Design Report

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i1615 1tin(jo.- Subdivision .... _ _� .._._ ...._._....�.��..�..:...�...._..._:..............+.i+r..a.;:....:..:r.:..a:N. Pag12 4 Lot 2, Block 1 Peres PB21 thru PD26. Borings BB21 thru PR23. perc rates for bith t:rimary and alternate sites are acceptable. Slopf•n are nearly level at the tested sites, ranging from 0 to 3%. Mottling indicated below 2', with actual water table at 3.2 to 4.21. A standard mound system should be used due to the pr,:sence of shallow saturation zones. Lot 3, Block 1 Peres PB31 thru PB26. Borings BB31 thru 8833. Slopes in the primary site are apprcxirately 6-81, on a slight flattening Of the 10-12% slopes surrounding it. Borings in the primary site indicate 1 to 2 ' of loamy topsoil over a 6" layer of organic clay topsoil over a plastic sandy clay. Actual water table at the primary site was below 51. However, the high plasticity indicates a heavy clay that is probably baturated. The secondary site was rnottled below 1-5 feet with an actual saturated zone at l' depth. Coupled with a slope of 10% the secondary site is marginal for a round aystcm and would require at least 2' of sand bane an part of the design. I suggont that standardpresoure moi,nd system ba required for both sites with addea sand depth for Lhe second-1-y system. Plc2se note that this lot is the r..c3t tenunus in the subdivision in terrii of olope and soda r_onaideration far using a round system. Should a proposed housa location encroach on either of the tested sites, careful revica and possible additional tcr;tinq will be needed to ensure that a mound can still be used. The site do^s not appear capable of supparting any kind of R trench sycte.'m. Lot 4, Block 1 Peres PB11 thru PE346. "orings 1041 thru BB43. Slc, co average 51 - 7% overall. Borings indicate actual ••eater table at 4' with mottling at a depth of 3-4' for tha primary and 2' at the accondary site. Porc ratc3 wer^ fairly uniform throughout thono teatcd sires. A deFr::�ssion/draina,^:• y to the ir..: ^diate south of the taatel sitar r,a^t be rvoidecl during construction of '::re a;,3tc,73. would rccon rend a standard proaaure round for both niter. Lot 5, BV nk 1 Peres PI351 thru PD56. E::)ri.ngo D351 thru DD53. Slopo3 are 31 to 6% overall. Mottling at the prit:ary sito started at 2.7 co 3.5' :pith actual water table at 3.7 to 5.31. z-his site in acceptable for a standard mound The alternate site has a perc rate conjidored too slow for any system by close scrutiny shows that the pores were taken at depth its the candy clay subsoil, not in the topsoil. In general, throughout the entire subdivision the touting dons at a dirth of 12", in tho topsoil, indicates acceptable percolation rateq, with tooting at 24" or more indicating slowar, marginal perc rhea. in my opinion, thin situ in no different than c.o-.t of the cthora, and would have an acceptable perc rntc if tested at the 12" depth in thu, sandy learn topsoil. NO further 'tooting should be rrqui.redt a m.-)und uyntrm is rero-mended.