09-10-1984 Council Packet - Laserfiche WebLink

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TO: Alan P. Olson, City Planner FkOM: Michael P. Gaffron, Septic System Inspector D.:TE: August 9, 1982 SUBJECT: Paul Smith, 2477 Dunwoody Avenue - Septic System Review On Wednesday, August 4, 198" I received a call from Paul Smith requesting an inspection of his septic system. I subsequently made the inspection that same day. The system consists of two septic tanks, one of which we opened. No drainfield is known to exist. The tank that was opened had a 3' liquid depth and approximately 3' air space/ manhole above the liquid for a total depth below the surface of about 6'. The surface at that location is about 6' above lake level, hence I conclude that the tank bottom is at the same elevation as the lake. This tank did not appear to have a solid concrete bottom. Horizontal distance from this tank to the lake was measured at 27'. The second tank, which was not opened, was pointed out by Mr. Smith as being straight towards the lake from the first tank, and is presumed to be also dt lake level and about 20' from the lake. No visible evidence of current or previous surface discharge from the tanks was seer.. No pipe leading into the lake from the septic system was noted. However, with the non -sealed tank bottom at lake level, and only 20-30' from the shore, the system does not meet shorelar,d septic system requirements (75' from shore, 3' above water table) and Is a potential pollution, hazard. ADDENDUM 9-7-84 It would be extremely difficult or impossible to prove a health hazard now exists on the Smith property, i.e. There is no visible or discernible discharge of sewage and with no recent usage of the system, it is unlikely that analysis of the water at the lakeshore would conclusivuiy show a pollution threat. However, we will be sampling in the Crystal Bay area this week and will collect samples from Smith's lakeshore for analysis. We can show potential health and pollution problems by inference, based on the actual location and design of the system in relation to code requirements. For phosphorus retention reasons, we require a 75' lake setback for septic systems. This system is much closer than the required 75', does not meet either local or DNR minimum setbacks, and we can infer that there is a potential phosphorus discharge to the lake. Since the tanks have open (not sealed) bottoms at lake level, we infer they discharge untreated sewage directly intc the Lake- shore water table, and we infer based on the lack of a required vertical separation distance between the discharge point and the water table, that the sewage never gets treated, hence viruses and pathogenic bacteria may be carried into the :ake with the natural groundwater flow.