10-28-1996 Council Packet - Laserfiche WebLink

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KOCH’S SOIL TESTING P.O.BOX 81 LORETTO.MN 55357 TEL: (612) 479-2637 Edna Albce Estate 1/2/96 Job Site: 1575 Long Lake Blvd., Orono, Mn. Percolation tests and soil borings were done on the above lot on 11/7/95 to determine what type of drainfield could be installed to replace the current system which is not a xTe'^^^raBVperedation rate was 19.9 min/m. and the depth to mottled soil was at 39-48 inches.* See the enclosed soil borings and percolation tests for the details. Note: the perc, test and soil borings were done on 11/7/95. , . , • Initially a pressurized system was designed for this properly due to the mottled soil level of39 inches in Soil Boring#!. Upon further soil boring investigation on 12/27/95 with Mr. Jim Anderson (University of Minnesota), Mike Gaffron and Steve Weekman (City of Orono), Duane Ritter (Du^e Ritter Excavating, Rockford, Mn.) and Robert Koch (Koch Soil Testing, Loretto, 1^.) present it was the general consensus that a 10 inch gravelless trench system could be installed. Three soil borings were taken that day (12/27/95) and mottled was oun a 42 inches to 48 inches. It was agreed that the gravelless trench system would be the oreferred system for this lot. . „ The depth of the gravelless on the downhill side should be at least 6 inches into cxistmg soil The soil located in between the trenches should be scarified up with the teeth of the backlioe and similar topsoil (black loam) be added into this area to ensure a minimum cover depth of 6 inches over entire drainfield area. The decision on when the placemen of topsoil will be done will be up to the contractor/installer as proper drainage areas wi have to be developed at the same time. The amount of 10 inch gravelless pipe needed for a 3 bedroom home b^ed on 450 gal./day water usage with a perc. rate of 19.9 min./inch would be of the following size: Overall size: 750 sq.ft. Total amount of pipe needed: 250 ft. t-. r ^ However, it was felt that only 80% of the pipe would be filled with effluent. Therefore, the system should be increased by 20% or to a size of 900 sq. ft. Overall drainfield size: 900 sq. ft. Total amount of 10 inch gravelless pipe needed; 300 ft. , « nr r,mn This would amount to using 5 trenches. (1-50 ft., 1-95 ft., 1-80 ft., 1-70 ., - ) P boxes should be used to distribute effluent to the trenches. Two 1,000 gallon sealed septic tanks should be used. These tanks should be pumpe ou every 2-3 years. This practice will enhance the life of tiie system. Robert Koch MPCA Certified