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Home My WebLink About1976-08-16 Soil Boring Report♦ I I An Expansion of Soil Eniiincering Services, Inc. I MINNEAPOIIS/ST. PAUL MOO S. Counly Rd. 18. P.O. Box 35108, Mpit., Mn. 55435 / 612-941 -5600 NORTHERN MINNESOTA 3218 E. 18th Avcnui, Nibbing. Mn. 55746 / 218-263-8869 ENGINEERING TESTING I I I I i I I I I If I I I I I f I I limMjnr.f, rmuhm P.ltAJIOfllSON. CkmMmn C 6. KNUU r. f.. Vm Pm. inginnruif a.a MOHAHAM A. C., Mw ^ Tttmt August 16, 1976 Johnson 6 Peterson, Inc. 18104 Minnetonka Blvd. Wayzata, MN 55391 2-oT • ) S £- . S Attn: Mr. Terry Johnson Re: 76-301 PRELIMINARY SOIL BORINGS 6 PERCOLATION TESTS Fairview (County Road 84) Orono, Minnesota Mr. Johnson: 0 As requested, we have recently conducted a preliminary soils investigation consisting of 8 power auger borings and 6 percolation tests. The borings were taken to determine the general soil and water conditions over the above referenced subdivision. The percolation tests were conducted to provide preliminary information relative to the soil absorptivity rates. The borings and percolation tests were taken at the locations shown on the attached sketch. Field locations were determined by topographical features shown on the topographical survey provided by you. Surface elevations were interpolated from the contour elevations shown on this survey. Investigation Methods: The power auger borings were completed using a CME-45 truck- mounted power auger unit. The soil classifications and depths as shown on the attached Logs were inferred from the soils brought to th^ surface by the continous flight feature of the auger. The depth of strata changes is thus considered approximate. rnN<iMTiw« riuriMrrRC« amo MAirniAi^ I J.. • I 76-301 Johnson § Peterscm, Inc. -2-August 16, 1976 Mineral soils encountered in the borings wers classified in accordance with the Unified Soils Classification System. 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 examination. Percolation tests were run in 6-inch diameter holes, drilled to a depth of 36 inches, in accordance with the procedures normally used on lots that will be developed residential!* . In accordance with standard procedures, the holes were permitted to soak overnight before conducting the tests. Each of the borings was probed immediately after completion to check for the presence of groundwater. Results: The Log. of Soils encountered in the borings and the water level observations are shown on the attached Log of Boring sheets. Boring B-1 encountered brown, silty sand overlying slightly silty sands to the respective termination depth of ISh feet. Borings B-3 and B-4 typically encountered a sandy clay tp a clayey sand overlying a stratum of slightly silty sand to silty sand at or near the termination depth of the borings. Borings B-2 and B-5 through B-8 all encountered a dark brown to black silty sand to depths on the order of 2 to 6 inches and then encountered strata of verying thickness and depths of sandy clay and silty clayey sand pTarial tin to the termination depth of each of these boringsy A black sandy was eiiLuuiiLei'd to Sl de^^th fPCT Yn boring B-7. In probing the borings immediately after completion, ground water was not encountered in borings B-5 and B-6. Water was encountered at a depth of 11 feet in B-1, 1 flh frn% ii n H Z An/t ^‘^*1 feet in B-3. 9U feet 1^ ft-7 feet in located at the southwest edge of the property. The contour elevation of the edge of this swamp to be roughly 930±. It then appears from this information that the groundwater table over the area under investigation would be above elevation 930. In boring B-1. water was encountered at an elevation of 945. In boring B-4, water was encountered at elevation 934.5. There is considerable variation between Ihese water level readings. Because of the cohesive nature of the soils encountered, considerable time is required in order for the groundwater to stablize in the borings. It t I I I I I I IIj I i I I D i I 76-301 Johnson 5 Peterson, Inc.-3-August 16, 1976 does not appear that the groundwater levels were completely stabilized at the time the water level checks were made. Also, some of these are possibly "perched" water levels. Water levels should be expected to show normal seasonal and annual fluctuations. Percolation tests indicated soil absoiptivities, in minutes per inch (mpi) as follows: Test # Surface Elevation Soil At Test Depth Rate Cmpi) P-1 P-2 P-3 P-4 P-5 P-6 956.0± 955.0± 953.01 953.01 978.01 943.51 Silty Sand (SM) 5 Clayey Sand (SC) 240 Sandy Clay (CL) 120 Clayey Sand (SC) 240 Clayey Sand (SC) 48 Sandy Clay (CL) 240 Preliminary Recommendations. You have indicated that current plans call for developing this site as a single family, residential area. Lot sizes currently planned are on the order of 2 acres with each dwelling having an individual sanitary disposal system. Borings were taken generally in the low areas across the site and provide preliminary information relative to the general soil types encountered in this area. The borings did not encounter any highly organic soils such as peat or muck, how ever, a black mineral soil was encountered to a depth of 3 feet in boring B-7 which was put down in a low area near the southeast corner of the site. Power auger borings do not provide information relative to the strength parameters of the various soil types encountered, however, mineral soils of the types brought to the surface by the auger generally are of sufficient strength to support single family dwellings without detrimental settlement. Black mineral soils are likely quite soft and would not provide an adequate foundation. For any houses in low areas soft black soils will likely have to be removed in their entirety from building areas. There is considerable variation in the results of percola tion tests conducted. Percolation test #1, which was conducted in a more sandy material, was found to have a percolation rate of 5 mpi, which indicate that the soil in this area can absorb water relatively quickly. Results of percolation test P-5 put down in a moic cohesive soil, indicates that these soils are less permeable with a rate of 48 mpi, however, a percolation rale of iliis magnitude would be considered acceptable. .1 I I I I I I I I I I i \\ \\ • \ I 76-301 Johnson Q Peterson, Inc.«4 August 16, 1976 Percolation tests P-2, 3, 4, and 6 indicate individual absorptivities of 120 or 240 mpi. These values are outside the limits for typical individual sanitary sewer systems. Unless additional investigations would reveal more absorptive soils in other areas of these lots, specifically designed systems would be necessary to meet individual requirments and provide a system to function satisfactorily. Of necessity, the area of the power auger borings and percolation tests in relation to the area of the subdivi sion and the depth of the borings are limited. Suggestions and/or recommendations of this report are opinions based on the data obtained from the borings. If we can be o:; further assistance in evaluating these data, taking additional borings or percolation tests, kindly contact us at your convenience. Very truly yours. BMUN ENGINEERING TESTING, INC. Dennis M. Rietschel • Engineering Assistant / Braun, P.E. resident DMIl/JS3:skf •••••••« .•«• Mi la.. 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(Till) 14 a S. 16 SANDY CLAY, with a trace of gravel, fine to medium- pray, wot- (Till) CL SILTY CLAYEY SAND, fine to medium-grained, brown, 18.5 waterbearing. (Till) 3M-SC Water level dcr.m 9.5' immediately after withdrawal of auger. BORIN^ B-8 DATE: 8/5/76 SCALE: 1”»4 SURF.E 961.5 LOCATION: 90'W, 90' fs. of N.E. comer Lot 1, Block 3. Depth 2 Descrio-I^j;^' o^meriols SILTY SAND, fine to medium grained ^^grayish brown, dry SM SANDY CLAY, with a trace of gravel, brown, wet. (Till) 18 0 f / 7 CL Water level down 18' Immediately after withdrawal of auger. I i ! t I L i z 1 i \ iI It i i I I I