03-07-1977 Planning Packet - Laserfiche WebLink

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j s SRAUH p. I.. ^endtni f H ANOIRSON. VtcrPrn Ofm»ttong C 6 AHUSl f. V/ictf h9i ingin99fin§ ^ PERCOLATION 11, Richard Dohert;* ad sota jntly taken :o assist ‘ ground- Ltary the above js were and as at the »4orth Arm t 5 with ruary 17, soil logs were the con- strata encoun- assified ification sual and 7 is led to our :ations by tain in e for your . . :■■■ . : ■■ ■ illrvf - '. O'V' V -i ii f .;“.v LhVTl 77-045 Braucr ^ Assoc., Inc.-2-February 24, 1977 The borings were probed immediately after their completion to check for the presence of groundwater. The borings were also rechecked prior to leaving the site on February 17. Absence of groundwater was noted in both probings of the borings to their respective 15-foot termination depths. A recheck of the boring 1 week later also encountered no groundwater to the 15-foot depth. The percolation tests were run in 6-inch diameter holes drilled to an approximate depth of 36 inches, in accordance with procedures recommended by the Minnesota Department of Health (MUD) and with the procedures recommended by the City of Orono. In accordance with these procedures, the bottom and sides of the holes were scratched with a knife blade to remove any smeared soil surfaces and to orovide a natural soil interface into which the water may percolate. Two inches of coarse sand was then placed in the bottom of the holes to prevent scouring. The holes were then carefully filled with clear water to a minimum depth of 12 inches over the top of the sand layer and allowed to soak overnight with the percolation tests being conducted the following day. An insulation material was placed over the holes prior to leaving the site to prevent freezing of the water and soils overnight. RESULTS: The log of the soils encountered in the borings and the water level observations are shown on the attached Log of Boring sheets. 1 Boring B-1, taken in Lot 5, encountered a coarse alluvium silty sand, brown in color, with a trace of gravel, from the surface to the 7-foot depth. Clayev sand glacial till was then encountered from the 7-foot depth to the 15-foot termination depth in the boring. Boring B-2, taken in Lot 4, encountered a dark brown silty sand topsoil layer from the surface to approximately the 4- foot depth and was immediately underlain by coarse alluvium silty sand between the 4 and the 7-foot depth. A clayey 'sand glacial till was then encountered from the 7-foot depth to approximately the 12-foot depth and was in turn underlain by a sandy clay glacial till to its 15-foot termination depth.