Laserfiche WebLink
Wastewater Treatment System *.r/ -.WWFALL CREEK <br /> •- Engineering Report ;O ENGINEERING,INC. <br /> Table 3.5. Wetland Organic Loading Rates—Current Flow Rates <br /> Process Stormwater Wetland Wetland Septic <br /> �. Water Flow Flow Loading Det. Time Det. Time <br /> Qp (gal/mo) Qs (gal/mo) L (kg/ha-d) (day) (day) <br /> January 2,055 106,926 19 11 2 <br /> February 6,962 100,636 50 10 2 <br /> March 7,707 77,254 48 14 3 <br /> April 7,459 33,773 45 29 5 <br /> May 5,138 17,765 29 54 9 <br /> June 4,973 2,797 28 167 27 <br /> `' July 5,138 994 28 227 35 <br /> ,%W August 30,830 247 169 46 7 <br /> September 49,725 7,511 282 24 4 <br /> October 43,675 32,021 242 17 3 <br /> November 19,890 57,465 117 16 3 <br /> December 20,553 74,905 118 13 2 <br /> Projected wetland loading rates during the months of crush, up to 282 kg BOD/ha-day (252 lbs <br /> BOD/ac-day), are expected to be higher than the EPA's suggested BOD loading rate of 112 kg <br /> BOD/ha-day (100 lbs BOD/ac-day). However, these rates are well within the successful <br /> experimental values of 1650 kg BOD/ha-day (1470 lbs BOD/ac-day). Even though there are <br /> some months with high loading rates, the average yearly loading rate is 98 kg BOD/ha-day (88 <br /> �. lbs BOD/ac-day) and there are many months were the loading rate is much lower. It is expected <br /> that some of the low loading months will help to balance the high loading months, allowing <br /> additional organic processing and recovery time. <br /> 3.5. Hydraulic Detention Time <br /> _ The minimum recommended detention time for a subsurface flow wetland is 5 to 7 days. The <br /> proposed wetland's hydraulic detention times, as shown in Table 3.5, range from 10 days in <br /> during the height of the wet season to over 200 days during the dry season. During crush the <br /> hydraulic detention time is approximately 20 to 25 days. All of these detention times are well <br /> _ above the recommended 6 to 7 days. <br /> To confirm the treatment efficiency, FCE calculated the expected removal efficiency for the <br /> proposed wetland. A first order equation was used to model pollution removal, as follows: <br /> �. Ce =e-KT' <br /> _ C', <br /> where Ce= effluent BOD, KT=temperature dependant first-order rate constant, and <br /> Co= influent BOD, t= hydraulic detention time. <br /> KT was calculated from the following equation: <br /> 1ESSIE's GROVE WINERY MAY 2002 <br /> 14 <br />