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CITY of ORONO <br />Yost Office Box 66•Crystal Bay, Minnesota V)323•Municipal Offices <br />On the North Shore of Lake Minnetonka <br />March 22, 1985 <br />Jan Gibson <br />% Norwest Mortgage <br />3601 West 77th Street <br />Suite 960 <br />P.O. Box 35826 <br />Bloomington, MN 55435 <br />Re: Septic Syste - 65 Cygnet Place <br />Dear Ms. Gibson: <br />In reference to your request for an opinion on the adequacy of <br />the existing septic system for the above referenced house, I am <br />submitting the following brief report, including certain assumptions <br />and facts which have a bearing on this opinion. <br />Factors which affect the "adequacy" of a septic system, i.e. it's <br />ability to treat and dispose of a given effluent load, include the <br />following: <br />1) Design of the system <br />2) Construction practices used <br />3) Location of the system <br />a) Topographically <br />b) In relation to surrounding structures <br />4) Soil permeability and soil water conditions <br />Relating to the system in question, I will deal mostly with the <br />soil conditions. The City has no record of percolation tests Cr soil <br />borings for this property, which tests may or may not have been r•ade <br />prior to system installation. This testing for new septic systems was <br />not required by the City of Orono until 1978. The system in question <br />was installed in 1973. We must therefore rely on the Hennepin County <br />Soil Survey and our knowledge of and experience with soils in the <br />area. The Soil Survey identifies soil types only in general terms and <br />normally does not indicate soil variations smaller than 2 acres in <br />area, hence it is not generally used as a final authority in designing <br />septic systems. However, it is the best information available in this <br />case. The soils map indicates a Hamel loam - Kilkenny loam <br />transitional area at this site. Hamel loam generally has seasonally <br />saturated zones at 1-2' deep and is generally therefore not suited for <br />a trench or bed type drainfield system, (also due to variable but <br />generally slow percolation rates). The Kilkenny loam gererally has <br />slower percolation rates but seasonally saturated zones below 5' ;r <br />all seasons. A "mound" drainfield system is often requirea <br />Kilkenny soils because of the slow permeability. <br />BUILDING A ZONI\t, 473-7357 • ADMINISTRATION A I I%A\U 473 735H • pl HI U IAORKS 471 7354 <br />ASSESSIN( <br />