HomeMy WebLinkAboutEngineer Report 11.06.2013November 6,2013 Garfield County Building & Planning 108 8th Street, Ste. 201 Glenwood Springs, CO 81601 RE: OWTS-361 C.R. 311, Silt, CO BUI #13019.01 To Whom it May Concem: The purpose
of this letter is to size the septic tank and dosing tanks for the proposed recreational improvements at the Ruby of the River Ranch near Silt, Colorado. The sepctic field will be designed
at a later date. It is our understanding that the Applicant, Mr. Thom Toler, desires to construct ten (10) new campsites on the property and that these campsites will share 2 or more
bathrooms (sink, toilet, shower) and one coin operated laundry machine. Based on CDPHE, wacc On-Site Wastewater Treatment Regulation #43, effective June 30, 2013, the estimate of Average
Daily Wastewater Flow (ADWF) for the proposed improvements is: Campground: 50 gpd per campsite Laundry: 400 gpd per self-service commercial washer ADWF = 50 gpd * 10 campsites + 400
gpd * 1 washer = 900 gpd As a non-residential application, the septic tank shall be sized to permit detention of incoming wastewater design flows for a minimum of 48 hours. Therefore,
the septic tank size shall be: Septic Tank: 900 gpd * (48 hrs /24 hrs) = 1,800 gallons (2000-gallon tank). The associated dosing tank shall be sized for 3 doses per day. Therefore, the
minimum dosing tank size shall be 900 gpd /3 = 300 gallons. As an option, the two tanks could be combined into a single tank. Single tank options are: 1) A 2,500-gallon three compartment
tank which contains at least 1 ,800-gallons of combined storage in the first two chambers and is equipped with a basic dosing pump arrangement; or 2) A 2,250-gallon two compartment tank
equipped with an approved pump filtering devide to assure that only liquid effluent will be discharged (Orenco ProPak or approved equal). It is our understanding that the tanks may be
subject to buoyancy. Therefore, the tanks should be concrete and be strapped down with buoyancy counteracting blocks of the following equivalent sizes: 500-gallon tank: ((500 gal*0.13368
cf/gal*62.4 pcf)-4000 Ibs)/145 pcf )*2 FS = 4 CF 2,000-galion tank: ((2000 gal*0.13366 cf/gal*62.4 pcf)-15000 Ibs)/145 pcf )*2 FS = 24 CF 2,250-gallon tank: ((2250 gal*0.13366 cf/gal*62.4
pcf)-15000 Ibs)/145 pcf )*2 FS = 52 CF 2,500-gallon tank: ((2500 gal*0.13366 cf/gal*62.4 pcf)-15000 Ibs)/145 pcf )*2 FS = 61 CF t9j~llact me at 945-5252 x 1.