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I <br />I <br />I <br />I <br />I <br />I <br />IIj <br />I <br />i <br />I <br />I <br />D <br />i <br />I <br />76-301 <br />Johnson 5 Peterson, Inc.-3-August 16, 1976 <br />does not appear that the groundwater levels were completely <br />stabilized at the time the water level checks were made. <br />Also, some of these are possibly "perched" water levels. <br />Water levels should be expected to show normal seasonal and <br />annual fluctuations. <br />Percolation tests indicated soil absoiptivities, in minutes <br />per inch (mpi) as follows: <br />Test # <br />Surface <br />Elevation <br />Soil At <br />Test Depth Rate Cmpi) <br />P-1 <br />P-2 <br />P-3 <br />P-4 <br />P-5 <br />P-6 <br />956.0± <br />955.0± <br />953.01 <br />953.01 <br />978.01 <br />943.51 <br />Silty Sand (SM) 5 <br />Clayey Sand (SC) 240 <br />Sandy Clay (CL) 120 <br />Clayey Sand (SC) 240 <br />Clayey Sand (SC) 48 <br />Sandy Clay (CL) 240 <br />Preliminary Recommendations. <br />You have indicated that current plans call for developing this <br />site as a single family, residential area. Lot sizes currently <br />planned are on the order of 2 acres with each dwelling having <br />an individual sanitary disposal system. <br />Borings were taken generally in the low areas across the site <br />and provide preliminary information relative to the general <br />soil types encountered in this area. The borings did not <br />encounter any highly organic soils such as peat or muck, how­ <br />ever, a black mineral soil was encountered to a depth of 3 <br />feet in boring B-7 which was put down in a low area near the <br />southeast corner of the site. <br />Power auger borings do not provide information relative to <br />the strength parameters of the various soil types encountered, <br />however, mineral soils of the types brought to the surface <br />by the auger generally are of sufficient strength to support <br />single family dwellings without detrimental settlement. Black <br />mineral soils are likely quite soft and would not provide an <br />adequate foundation. For any houses in low areas soft black <br />soils will likely have to be removed in their entirety from <br />building areas. <br />There is considerable variation in the results of percola­ <br />tion tests conducted. Percolation test #1, which was conducted <br />in a more sandy material, was found to have a percolation rate <br />of 5 mpi, which indicate that the soil in this area can absorb <br />water relatively quickly. Results of percolation test P-5 put <br />down in a moic cohesive soil, indicates that these soils are <br />less permeable with a rate of 48 mpi, however, a percolation <br />rale of iliis magnitude would be considered acceptable. <br />.1