1977-05-16 Septic System Design Report

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77-199 Nitz, Inc. -2- May 16, 1977 Mineral soils encountered in the borings were classified in accordance with the Unified Classification System (ASTM D2487). A copy of that chart is attached. Representative samples of the soils brought to the surface by the auger will be retained in this office for a period of 60 days to be available for your examination. Percolation tests were run in 6-inch diameter holes, drilled to a depth of 36 inches, in accordance with procedures recommended by the City of Orono. The holes were permitted to soak overnight before conducting the tests. The boring was probed immediately after completion, as well as approximately 24 hours later, to check for the presence of groundwater. RESULTS: The log of soils encountered in the boring and the water level observations are shown on the attached Log of Boring sheet. The boring generally encountered a sandy, clay glacial till from the surface to the 11-foot :depth where it then encoun- tered a slightly silty, coarse alluvium sand to the 20-foot termination depth. In probing the boring immediately after completion, ground- water was not encountered. Approximately 24 hours later, the bore hole was probed and again groundwater was not encountered. Even though groundwater levels at the present time may not be normal it is our opinion that the water table in the area of the proposed drainfield is somewhat below the 20-foot termination depth of the boring. Percolation tests indicated soil absorptivity in minutes per inch (mpi) as follows: Surface Soil At Rate Test # Elevation Test Depth (mpi) P-1 974.8 Sandy Clay 120, P-2 974.7 Sandy Clay W P-3 974.0 Sandy Clay 100, P-4 974.0 Sandy Clay 120. P-5 973.5 Sandy Clay 55 P-6 973.5 Sandy Clay 120' The average of the 6 initial percolation tests is then 100 mpi. BRAUR' ENGINEERING TESTING