SU0002230 - Laserfiche WebLink

Home Browse Search

Wastewater Treatment System FALL CREEK Engineering Report ENGINEERING,INC. 3. DESIGN CRITERIA AND CALCULATIONS—CURRENT EXPANSION The proposed design for the treatment system includes a hyperbolic screen for removing coarse solids, a dual chambered septic tank for settling, and a sub-surface flow vegetated wetland. This treatment system will reduce concentrations of BOD, suspended solids, and dissolved solids and will help neutralize pH. Following treatment and BOD reduction the treated water will be applied to a vegetated slow-rate land disposal system. The wastewater treatment wetland has %W been designed to remove biochemical oxygen demand (BOD) in the Winery's process ,,, wastewater by at least 95% based on design flows of 1,660 gallons per day, organic loading of 69 lbs/day, and a surface loading rate of 160 lbs BOD/ac-day. The following design criteria were used in designing the treatment system: (1) Parabolic Screen. A parabolic screen will be used at the beginning of the treatment train to remove coarse solids from the process wastewater. (2) Septic Tank. Screened wastewater will flow via gravity to a new 5,000-gallon septic tank. The tank will be used for wastewater stabilization and limited anaerobic digestion. From the septic tank, wastewater would flow through a distribution manifold and through the wetland itself. `, (3) Monthly Water Balance. Monthly water balance calculations were performed on the %0 proposed wetland to determine the feasibility of the treatment system. (4) Organic Loading Rates. The EPA recommends a constructed wetland mass loading rate �r of approximately 112-kg BOD5/ha-d (100 lbs BOD/ac-day) (USEPA, 1988). However, experimental studies have shown that BOD loading rates of up to 8 times this recommended value (1640 kg BOD5/ha-a or 1464 lbs BOD/ac-day) have produced significant organic reductions in winery wastewater(Shepherd et al, 2001). Results of �- that study also found that despite fluctuation in inlet wastewater strength, the outlet water quality was generally consistent and occasional excessive organic loading did not interfere with treatment. (5) Hydraulic Detention Time. It is generally expected that a wetland detention time of at least 6-7 days is optimal and that any shorter than that will not provide adequate treatment. (6) Stormwater Detention. The treatment system will have a secondary benefit of its ability to hydraulically dampen flow variations. The wastewater system at the Winery facility receives both process wastewater and stormwater; therefore the system has to be able to handle both flow types. The wetland was designed to contain and treat runoff volume resulting from the 100-year 24-hour storm flow. (7) Land Application. After treatment, process wastewater and stormwater will be applied to _ landscaped areas at the winery using solid set sprinkler irrigation. .IESSIE's GROW WINERY MAY 2002 8