1978-02-13 Septic System Design Report

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78-08B Mr. David Nitz -2- February 13, 1978 The percolation tests and the borings were either conducted with a truck -mounted power auger unit; or, in those areas inaccessible to truck, with a hand operated drill. All operations were c..►ducted in conformance with City of Orono specifications and in accordance with those procedures as indicated to you in previous percolation test reports conducted for various lots in the addition. The borings were probed immediately after their completion to check for the presence of groundwater and once again the following day. Groundwater was encountered at the 4-foot depth in boring B-1, however, was not enc untered at the time of the final reading in boring B-2. RESULTS: The log of soils encountered in the borings and the water level observations are shown on the att:+.h,2d Log of Boring sheets. Soil boring B-1 generally encountered a frozen silty clay topsoil to a depth of approximately '.�j feet, underlain by a silty clay lacustrine deposit to a depth of 8 feet. Silty clayey sand glacial till was then encountered to the 17-foot termination depth in this boring. Boring B-2 encountered a silty sandy clay topsoil from the surface to approximately the 1h-foot depth. A sandy clay glacial till was then encountered immediately below this layer to the 8-foot depth where a silty clayey sand till was then encountered to the 20-foot termination depth in the boring. The results of the percolation tests indicating the soil absorptivities in minutes per inch (mpi) are as follows: Surface Soil At Test N Elevation Test Depth P-1 92.5 Silty Clay (CL) P-2 93.5 Silty Sand (SM) P-3 92.3 Silty Clay (CL) P-4 91.3 Silty Clay (CL) P-5 92.2 Silty Clay (CL) P-6 92.5 Silty Clay (CL) P-7 91.8 Silty Clay (CL) P-8 98.4 Silty Clayey Sand, (SM- SC) P-9 92.6 Silty Clay (CL) P-10 96.9 Silty Clayey Sand, (SM-SC) Rate m i 80 30 120 240 80 75 40 BRAUR" ENGINEERING TESTING