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' 78-008A <br />' David Nitz, Inc. -2- January 24, 1978 <br />Mineral soils encountered in the boring were classified in <br />' accordance with the Unified Soils Classification System <br />(ASTM D2487). A copy of that chart is attached. Representa- <br />tive samples were then returned to our laboratory for <br />' verification of the field classification by a Soils Engineer. <br />Representative samples will remain in this office for a <br />period of 60 days to be available for your examination. <br />' The boring was probed immediately after its completion to <br />check for the presence of groundwater. The boring was also <br />rechecked prior to leaving the site at the time the percola- <br />tion tests were read the following day. Groundwater was not <br />encountered in both probings of the boring to its 17-foot <br />termination depth. <br />H <br />J <br />II <br />II <br />u <br />11 <br />The percolation tests were run in 6-inch diameter holes <br />drilled to an approximate depth of 36 inches, in accordance <br />with pr;,,.edures recommended by the Minnesota Department of <br />Health (WID) and with procedures recommended by the City of <br />Orono. In accordance with these procedures, the bottom and <br />sides of the holes were scr.:tched with a knife blade to <br />remove any smeared soil surfaces and to provide a natural <br />soil interface into which the water may percolate. Two <br />inches of coarse sand was then placed in the bottom of the <br />holes to prevent scouring. The holes were then carefully <br />filled with clear water to a minimum depth of 12 inches over <br />the top of the sand layer and allowed to soak overnight with <br />the percolation tests being conducted the following day. <br />RESULTS: <br />The log of soils encountered in the boring and the water <br />level observations are shown on the attached Log of Boring <br />sheet. <br />The soil boring generally encountered a coarse alluvial <br />silty sand from the surface to the 5-foot depth. A silty <br />clayey sand to sandy clay glacial till was then encountered <br />to the termination depth of the boring. Soils encountered <br />in the percolation tests generally ranged from sandy silty <br />sand to a sandy clay glacial till. <br />Results of the six initial percolation tests indicating the <br />soil absorptivities in minutes per inch (mpi) are as follows: <br />Surface <br />Soil At <br />Rate <br />Test # <br />Elevation <br />Test Depth <br />(m i <br />P-1 <br />83.1 <br />Silty Sand <br />48 <br />P-2 <br />78.8 <br />Sandy Clay <br />120 <br />P-3 <br />75.9 <br />Sandy Clay <br />120 <br />P-4 <br />75.5 <br />Sandy Clay <br />80 <br />P-5 <br />76.3 <br />Silty Clayey Sand <br />P-6 <br />78.8 <br />Silty Clayey Sand <br />ENGINEERING TESTING <br />