1985-07-23 Letter, Condition of Septic System

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To:Paul Johnson Prom:Michael P. Gaffron, Assistant Zoning Administrator Lyle Oman, Field Inspector ! Date: July 23, 1985 Subject: Septic System at 900 Dakota Avenue Our inspection of the septic system at the above property indicates the system appears to be functioning adequately for the current 2-member household. The drainfield at one point appears to have only 4"-6" of cover and at that point is moist and nearly spongy, but is not discharging to the surface. This system according to City records was installed in 1956. Although no as-built record exists of the system, from probing and from the pumping records, we would estimate that there are two tanks of 600-800 gallons each, and one drainfield line of probably no more than 300 square feet. Assuming a percolation rate in the range of 30-45 minutes per inch for the Hayden loam soils mapped at this site, the standard design rate for a drain- field would be 2 square feet of drainfield per gallon of waste per day. At a standard design rate of 75 gallons of waste per person per day, the drainfield should be 150 square feet per person, so the existing 300 square feet could only be expected to handle a 2-person household under optimum conditions. Now, realizing that the system is nearly 30 years old and may be starting to exhibit signs of natural biomat build-up or clogging, we expect it is only adequate to handle somewhat less than 150 gallons per day. With the assumption that a new family of 4 will be moving in, and based on the current signs of sponginess after a period where we have had only minimal rainfall for the last 3-4 weeks, it is our opinion that the system might not function adequately for a family of four, depending on their actual water use. (Studies have indicated that water use varies widely from family to family, ranging from as little as 25 to over 100 gallons per day per person. We have no idea of the actual current water use as there is no meter on the private well.) • It is impossible to verify or confirm exactly how much usage this system will stand, other than to use it until it fails (backs up into house or discharges to the surface). However, based on the situation, we would recommend that additional drain- field be added. Soil testing would be needed to design the drainfield based on the actual soil conditions at the site. The design would be based on the number of bedrooms at 2 persons per bedroom. •tf! ' Note that the City will not issue orders to repair until the system actually fails. Orono does not have a "housing code" as such, and there is no provision in our ordinances requiring upgrading of the septic system upon sale of the property.