Laserfiche WebLink
Jeanne A. Mabusth <br />June 15, 1983 <br />page 3 <br />table at 4.5', 5.3' - shallow trenches - maximum trench <br />depth 18" into original soil <br />- Alternate site - slope 6% - mottled at 3.8', water <br />table at 3.8' - modified shallow trenches* - maximum <br />trench depth 10" into original soil <br />Lot 4 Block 2 Percolation Rate Average 14 MPI both sites <br />- Primary site - slope 7% - mottling at 4.4', 5.5' - <br />water table at 4.4', 5.6' - shallow trenches - maximum <br />trench depth 1.7" into original soil <br />- Alternate site - slope 5% - mottling at 4.0* - water <br />table at 6.4' - shallow trenches - maximum trench depth 12" <br />into original soil. <br />*Modified Shallow Trenches - where water table or mottlini <br />is between 3.0' and 4.0* below the surface, a standard <br />12" rock depth (6" under pipe, 2" over) must be used in <br />conjunction with an appropriate depth of fill material <br />to retain a 3.0' separation between the bottom of trenclsiV'J <br />and the water table or mottling. Fill should consist of <br />material classified as loamy sand (USDA classification). <br />The original soil must he dryer tnai;* the plastic iiv.it <br />before plar-ing fill. The original surface must be scarified <br />or disced to break up the surface vegetation mat. The <br />loamy sand fill must be placed over the entire area so that <br />no trench will be located less than 10' from the edge of <br />the fill. The depth of fill required will depend on the <br />allowable depth of excavation into original soil based on <br />the water table or mottling. <br />I recommend that the subdivision be approved as proposed. The <br />developer should be warned to keep all traffic, fill excavation, <br />etc. away from the tested drainfield sites. In some cases <br />where road construction will be near the tested sites, extra <br />caution must be taken. <br />MPG:jl