09-22-1986 Council Packet - Laserfiche WebLink

Home Browse Search

iv f., April 21, 1986 Mr. H.W. Hull 2445 Woodhaven Drive Long Lake, MN 55356 RE: Septic System Status Dear Mr. Hull: CITE' of ORONO Post Office Box 66•Crystal Bay, Minnesota W23•Municipal Offices On the North Shore of Like Minnetonka The intent of this letter is to document the condition of your septic system, to attempt to determine possible causes for the intermittently failing condition, and suggest possible remedies. Please realize that it is often extremely difficult to pinpoint the reason a septic system is failing, and failure is often due to a combination of many contributing factors, some of which are obvious, measurable, and verifiable and some of which can only be inferred based on previous expei•.ence and observation. In your particular case, we can point out a number of imperfect conditions that may or may not be contributing to the seasonal discharge from the system. I would make the following initial comments: 1. Prior to installation of the system, soil testing and a system design were completed by Mark Gronberg of Percor, Inc. Their report of 5-20-81 indicated the presence of soil mottling, an accepted indicator of seasonal saturation of the soil, at a depth of 4.5 feet at the east end of the proposed primary d.r-infield site, and no mottling at the midpoint of that site The percolation rate at the propose.. primary site was given as averaging 53.4 minutes -per -inch. The soil boring logs and percolation rates submitted suggest little or no evidence of an unusually high water table at the site. 2. Based on the reported percolation rates and 8epth to indicated sergonal saturation zones, Percor, Inc. a.,signed a shallow trench e• infield system based on a 3-bedroom home (2 persons per bedroom at 75 gallons per day capacity) which would by design be capable of treating and disposing of 450 gallons of effluent per day. The standard format design drawing submitted called for a maximum trench di h of 6-12" below the original surface and incorporated an "interceptor drain to remove excess soil water", -.lthough the interceptor drain was not called out in the design 0—tai1. Based on the reported depth of 4.5' to the seasonal BUILDING A ZONING - 47 3-7 35 7 ADMINISTRATION ♦ FINANCI - 4 73 7358 • PUBLIC %ORKS - 473 7359 ASSESSING