1983-06-30 Septic System Design Report

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TOM SMITH ASSOCIATES inc August 29, 1983 Marvin H Anderson Construction Co 8901 Idrndale Ave So Minneapolis, MN 55h20 ATTN: Fred Haas Consulting Engineers MUM SUBJBCTt Additional site evaluation for onsite sewage treatment system b300 Bayside, Orono, Minnesota Job # 197l Please refer to our initial report regarding the site evaluation at this address. After a meeting with you, Mike Gaffron of Orono, and Rick Stodola on August 2hth, it was determined that the higher ground to the south east of the house under construction should be considered for the treatment area, in lieu of the primary and secondary sites indicated in the initial evaluation. The purpose for this was better access for the contractor which would result in a more economical installation. Two borings and two percolation tests were performed on the site. The results of these are attached on the logs of soil t.,._ ngs and percolation test data sheets. In critical respects, the soil profile is very similar to the previous tvo locations evaluated, in that there is 2 to 2j feet of silty nlay forrest mat overlying a relative stiff clay soil with expected very slow permeability. Moreover, in boring B-4. mottling was indicated, although only slightly at just deeper than-2 feet below grade. This suggests at very wet periods, water will saturate the bottom of the forrest mat of silty clay as it is unable to penetrate the stiffer clay layer of glacial till below. For this reason, the sandy clay layer dneountpred at a depth of 2j feet in boring B-4, and at just over 2 feet at boring B-5 should be considered a limiting soil layer, requiring alternative treatment systems. Percolation tests taken with the bottom of the percolation test holes at 18 inches below grade showed percolation rates of 2h and 8.8 minutes pe inch at locations P-12 and P-* respectively. RECOMYENDATIONS : We recommend that the onsite system designed and recommended in our previous report be installed, however with the mound system placad in the vicinity of this new evaluation by P-12 and P-13 as shown on the attached site evaluation location plan. Because the house plan has been changt 'j a front loading garage, the location of the septic and pumping tanks st.juld be to the east of the ?,rage for better servicing access. Additionally a j HP high head pump wil.be necessary since greater pimping pressures will be required. A copy of the revised mound configuration for this site is enclosed. I hereby ce:.;ty thc! Ciis Wan, specificor-m of Very truly yours rcperi�..._, _ � ' �>y" ^r un3er my dirccf TOM SIMITH ASSOCIATES, INC cc Widmer Bros GMa K SMITH, PE City of Orono T�;0•.:, ; i:.: :.iii! Date �" �i — �� P.I.n. No. 9044 6109 Kimberly Road, Minnetonka, Minnesota 55343 16121 934-9031