2012/05/22 - SANITARY - SAN - Other

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A design concept of removing the existing system entirely to a depth of approximately 60 inches thereby removing any clogging mat and replacing the old systems rock and soil with an Astm C- 33 sand fill was proposed. This proposal along with tank replacement,the addition of surge tanks and the aerobic treatment units began to add significant cost to the replacement system with preliminary estimates reaching $150,000. April 1 sc of 2008 I submitted a preliminary design report to the DNR for the proposed upgrade of the system and on May 29`x,2008 I received a concurrence letter signed by Steve Smith DNR Engineer approving our design. For economic reasons the sanitary design submittal to the Dept. of Commerce was put on hold. Also in 2008 a water meter was placed on the main well serving the dining hall with showers,the four girls cabins, three boys cabins, nurses station and support staff housing for a total of 149 patrons. The purpose of the installation of the water meter was to take advantage of a code section(Comm 83.43 (6))that allows for a system to be sized by meter readings versus Table 4 public facility wastewater flows found in the component manual. This information could be beneficial in reducing the size of the proposed replacement system. Two other structures the Trinity Cabin(10 patrons) and the Luther Lodge (20 patrons)are serviced.by a separate well but for design purposes I will use the metered data. The meter readings taken during the high use camp weeks for 2008 average to 26 gallons/day/per patron and for 2009 the average was 28 gallons. This data was very helpful from a design standpoint as it includes all water usage from meals in the dining hall, showers and bathroom wastes. By injecting this data into our design we have been able to reduce the size of our pretreatment units and potentially our dispersal area. Even with this data the camps board of directors were reluctant to invest this amount of their funds based on donations, as it borrows from other areas such as maintenance. In June of this year Mr. Corbin contacted me regarding the installation of holding tanks for the camp. I told him that it was certainly possible as Burnett County's sanitary ordinance does not mandate the use of aerobic treatment in order to site a sanitary system. I further explained to him that the tank sizing would be based off of the estimated waste water flow of the camp. By using an average meter reading of 28 gallons a day per patron from 2009 for the total camp occupancy of 179 patrons per week I came up with an estimated flow of 5012 gallons per day. Multiplying the estimated (5012 gals.)times the five day capacity requirement of the holding tank component manual would require a holding capacity of 25,060 gals. Continuing my discussion with Mr. Corbin I related to him that we should look at the possibility of phasing in a new system over a period of time that would be of sufficient size to accept wastewater generated from the proposed multi-purpose building and to replace a current system for the one bedroom camp coordinators quarters. I explained that if we were able to receive approval through an individual site design to down size the holding tank capacity to only the amount needed to provide surge capacity and time dosing to our future aerobic treatment units we could save considerable dollars upfront while not wasting space in the limited area available for treatment tanks. The board agreed to move forward with the individual site design paperwork for the installation of holding tanks..