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Home My WebLink About1981-06-08 Septic System Design Reports AKANSON 4 NDERSON ASSOCIATES, Inc. P.O. Box 665 222 Monroe Street Mr. Ted Feig 15510 Post Road Wayzata, Minnesota 55391 Re: Feig Percolation Test Dear Ted: professional engineers and surveyors Anoka, Minnesota 55303 June 8, 1981 6121427.5860 At your request additional percolation testing was performed at Lot 1 Laurent Addition in Orono, Minnesota to identify new locations for the primary and secondary septic system areas. The location selected by you for the proposed house covers the area chosen, by us for the primary septic system in our percolation test report of April 14, 1981 (File: 795.01). Standard methods of percolation testing were employed. Elevations are relative to an assumed elevation of 100.0 based at a single spike placed in the east face of the power pole located near the south lot line of Lot 1 (see enclosed sketch). This report includes: 1. Soil boring logs 2. Percolation test results 3. Testhole location and septic system configuration sketch 4. Septic system design specifications 5. Discussion and recommendations. The soil boring log shows that silt loam to silty clay loam surface soils overlie mottled and gleyed clayey subsurface horizons. Soil mottles (spots of contrasting color) begin at 1.2 to 2.0 feet depth at the borenoles. Soil mottling is an accepted indicator of periodic saturation in soils. Gleyed areas (dull gray soil color) begin at 3.0 to 4.0 feet depth at the boreholes. Gleying forms in soils which are saturated and in a chemically reduced condition for long periods of time. Ground water was observed at about elevation 91.8 at the test site. Because the City of Orono requires at least three (3.0) feet elevation di."ference between the bottom of standard drainfield trenches and the water table or indicators of periodic soil saturation, an alternate type of septic system, the mound (also called the berm) system is recommended for this site. Percolation test results show that measured percolation rates are faster than the 120 minute per inch minimum rate for mound systems. civil • municipal 0 planning 0 soils land surveyiN Mr. Ted Feig - 2 - June 8, 1981 Soil Texture at Hole Elevation Depth(inches) Bottom of Hole Percolation Rate(min/in) A 98.4 26 Sandy clay loam 2.8 B 97.7 28 Clay loam 3.9 C 98.4 28 Sandy clay loam 6.4 D 97.7 26 Clay loam 4.9 05 97.7 24 Sandy clay loam 6.9 #6 97.5 26 Sandy clay loam 3.9 Measured percolation rates are rapid for the texture of the soil material in which the percolation tests were performed. The mound is designed to serve a four bedroom house. Design sewage flow is 600 gallons per day. With a design infiltration rate of 1.2 gallons per square foot per day for the medium sand fill material of the mound, the required rock bed area of the mound is 500 square feet. 600 gal/day - 1.2 gal/ft2/day - 500 ft` The mound design utilizes a rock bed 10 feet wide by 50 feet long which provides the needed rock bed area. With 3 to 1 finished slopes and 1.5 feet of medium sand fill below the rock bed, the mound will cover an area 31 feet wide by 71 feet long. The basal area of the medium sand fill material is 1,625 square feet (25 feet wide by 65 feet long). The design infiltration rate of natural soil with a percolation rate of up to 60 minutes per inch is 0.74 gallons per square foot per day. Therefore the required basal area is 600 gal/day r 0.74 gal/ft2/day - 811 ft2. This calculation shows that sufficient basal area is provided by the design. The pressure distribution system of the mound consists of Schedule 40 PVC plastic pipe. The supply pipe and manifold are 2.0 inch inside diameter pipe. The supply pipe should slope back towards the pumping chamber so that it drains after the mound is dosed. Tho laterals are 1.5 inch inside diameter pipes. The laterals should have 1/4 inch diameter holes drilled at a spacing of 3.0 feet. The laterals should be assembled to the manifold so that the holes point downwards into the rock bed. The distal ends of the laterals should be capped. Also, the last hole in each lateral should be drilled horizontally in the end cap near the crown of the pipe to facilitate air venting. .r If Mr. Ted Feig - 3 - June 8, 1981 A submersible effluent pump capable of delivering at least 37.5 gallons per minute against a total dynamic head of at least 15.9 feet should be selected. Headlosses are calculated as follow: 1. Vertical headloss of 10.0 feet between pump discharge (approx. elev. 90.5) and manifold (approx. elev. 100.5), (assumes sewer invert below footings) 2. Friction loss of 0.9 feet in 30 feet of supply pipe (3.03 feet per 100 feet 2.0 inch I.D. plastic pipe), 3. Five (5.0) feet to account for losses in distribution network. The primp should be rigged with mercury float switches to dose about 150 gallons of effluent to the mound. An additional mercury float switch should be installed on a separate circuit to an alarm device to warn of pump failure. The float switches should be rigged to allow 600 gallons reserve capacity in the pumping chamber. All electrical connections should be watertight. The sole purpose of soils data contained herein is evaluation of soil suit- ability for on -site absorption of septic tank effluent at the test site. Although soil texture and horizonation information and ground water elevation data may be helpful for the setting of basement elevations at this site, we cannot warrant any such interpretations or use of this data for other purposes. If you have any questions about information contained in this report, please feel free to contact me. Sincerely, HAKANSON ANDERSON ASSOCIATES, LNC: ,(YAX'L' Gary J. bun, Soil Scientist GJR/Jkw Enclosures File: 839.01 LOGS OF SOIL BORI 1'CGS PROJECT: Feig Percolation FILE No, BORING PtTHOD: 4" Flight Auger DATE: DEPTH 0.0 (feet) Dark brown silt loam Grayish brown silty clay loam Grayish brown clay loam with few yellowish brown mottles Gray sandy clay with many yellowish brown mottles, gleyed, wet Gray clayey sand, wet Grayish brown clay loam with many yellowish brown mottles, many gray gleyed areas, wet END OF BORING 0.8 2.0 3.0 4.5 6.0 8.0 Borehole A R FVATTM - QR L DEPTH 0.0 (feet) Dark brown silt loam Gray silty clay loam Gray clay loam with many yellowish brown mottles, coarse sand lens 3.0-3.5', wet i i Grayish brown sandy clay with many yellowish brown mottles, many gray gleyed areas, wet Gray silty clay, gleyed with many yellowish brown mottles EVD OF BORING O.E 1.2 4.0 5.5 2W 839.01 6/5/81 Borehole B F1 r:VATrn',i - 07 7 GROUND WATER AT 91.8 ON 6/5/81. GROUND WATER AT 91.5 ON 6/5/81. = Sai W'� M011 ASSOCLATES, INC, BY: z ti✓ LOGS OF SOIL KRI NGv PROJECT: Feig Percolation FILE NO, 839.01 BORING hIETHOD: 4" Flight Auger DATE: _ 6/5/81 DEPTH 0. (feet) Brown silt loam Gray silty clay loam Dark grayish brown sandy clay loam with many yellowish brown mottles Dark gray clayey sand, wet Gray silty clay with many yellowish brown mottles Grayish brown sandy clay loam with many yellowish brown mottles, many gray gleyed areas, firm END OF BORING 1.0 1.8 3.5 4.0 6.0 M Borehole C R PVATIOM - QA L DEPTH 0.0 (feet) 1.0 1.5 3.5 4.5 5.5 7.5 Borehole D F1 GVATTMI - Q7 7 Dark brown silt loam Gray silty clay loam Gray clay loam with many vellowish brown mottles Gray clay with many I yellowish brown mottles, massive Gray silty clay to clayey silt, saturated, very soft Gravish brown sandy clay loam with many yellowish brown mottles, many gray gleyed areas END OF BORING GROUND WATER NOT ENCOUNTERED. GROUND WATER NOT ENCOUNTERED. KN AISOiI IVIDERSON ASSOCIATES, Mc. BY: ,'✓ LOGS OF SOIL BORINGS PROJECT: Fein Percolation FILE NO, 839.01 BORING h1ETHOD: 4" Flight Auger DATE: 6/7/81 DEPTH 0.0 (feet) 0.5 1.5 3.5 6.0 M Borehole #3 R FVATTf1N - 97 _ 7 Dark brown silty clay loam Grayish brows. c'__-y loam with few yellowish'brown and red mottles Gray clay loam with many yellowish brown and red mottles, many gray gleved areas Brown clayey sand with many yellowish brown mottles, wet Grayish brown sandy clay with many yellowish brown mottles, wet END OF BORING GROUND WATER NOT ENCOUNTERED. IMM AMEM k%XIATES, INC. DEPTH BY: LOGS OF SOIL BORINGS PROJECT: — Feig Percolation FILE No, 839.01 BORING h]ETHOD: 4" Flight Auger DATE: 6/5/81 DEPTH 0.0 (feet) Dark brown silt loam Grayish brown silty clay loam Grayish brown clay loam with f-aw yellowish brown mottles Gray sandy clay with many yellowish brown mottles, gleyed, wet Gray clayey sand, wet Grayish brown clay loam with many yellowish brown -nttles, many gray gleyed :eas, wet END OF BORING M 2.0 3.0 4.5 6.0 8.0 Borehole A R FVATTrW - 9R_G DEPTH O.o (feet) 1.2 4.0 5.5 8.0 Borehole B FI PVATTM - 97.7 Dark brown silt loam Gray silty clay loam Gray clay loam with many yellowish brown mottles, coarse sand lens 3.0-3.5', wet i Grayish brown sandy clay with many yellowish brown mottles, many gray gleyed areas, wet Gray silty clay, gleyed with many yellowish brown mottles END OF BORING GROUND WATER AT 91.8 ON 6/5/81. GROUND WATER AT 91.5 ON 6/5/81. HAMWI AlURS01i ASSOCIATES, INC. BY: -�`ti✓ LOGS OF SOIL BORINGS PROJECT: Feig Percolation FILE No, 839.01 BORING PIETHom 4" Flight Auger DATE: 6/5/81 DEPTH o. (feet) - Brown silt loam Gray silty clay loam Dark grayish brown sandy clay loam with many yellowish brown mottles Dark gray clayey sand, wet Gray silty clay with many yellowish brown mottles Grayish brown sandy clay loam with many yellowish brown mottles, many gray gleyed areas, firm END OF BORING 1.0 1.8 3.5 4.0 6.0 8.0 Borehole C R FVATTM! - oa �. DEPTH 0.0 (feet) 1.0 1.5 3.5 4.5 5.5 7.5 Borehole D 171 cvATTMf - 07 7 Dark brown silt loam Gray silty clay loam Gray clay loam with many yellowish brown mottles Gray clay with many yellowish brown mottles, massive Gray silty clay to clayey silt, saturated, very soft Grayish brown sandy clay loam with many yellowish brown mottles, many gray gleyed areas END OF BORING GROUND WATER NOT ENCOUNTERED. GROUND WATER NOT FNCOUNTERED. H=r l AUMI AMIAMS, IK BY: LOGS OF SOIL BOR I NGS PROJECT: Feig Percolation FILE No, 839.01 BORING hIETHom 4" Flight Auger DATE: 6/7/81 DEPTH 0.0 (feet) 0.5 Dark brown silty clay loam Grayish brcwn clay loam with few yeiiowish'brown and red o t Gray clay loam with many yellowish brown and red mottles, many gray gleved areas Brown clayey sand with inN yellowish brown mottles, wet Grayish brown sandy clay with many yellowish brown mottles, wet END OF BORING 1.5 3.5 M M Borehole #3 R FVATTM - 07 7 GROUND WATER NOT ENCOUNTERED. MMi AIUMI ASSOCIATES, INC, =6 BY: f �t eo.#o i Ppo. ,G c 'A ,EASCME/V 7" a C t a ;a mC) z k-A zmmm, i Da {� i _ f( � � !'�_' r � � • 1 � � I 1 T r D aZ Is Irn 3 1 SIDE SLOPE .•l v rn r r O v m I