1ELDORADO SPRINGS WASTEWATER MANAGEMENT DESIGNWho We Are:– Brooke Miller, Christian Romeyn, Matthew Condiotti, David DelagarzaExperienced in: – Wastewater Treatment Design– Water Resource Engineering– Hydraulic Systems Engineering– Water Quality AnalysisPresentation Overview– Summary of RFP from Eldorado Springs– Current and future conditions of the community– Regulations and permits– Assessment of 5 potential alternatives– Preliminary design of chosen alternativeEldorado Springs Request for Proposal– Currently no central wastewater treatment system– Most houses on septic systems– Boulder County suspects contamination of creek– Boulder County requested investigation of options– E.S.W.I. (citizens group) looking for solutionsProject LocationEldorado SpringsSouth Boulder CreekHighway 93Eldorado Springs Project Location0.5 0 0.5 Mile sNEWSWastewater (WW) Quantity Estimate– ESWI: 400 residents in 120 dwelling units– 60 gal/person/day + 10 gal/person/day infiltration & inflow = 70 gal/person/day– Eldorado Springs Artesian Water Company = 3750 gallons/day WW– Final WW estimate = 37,500 gpd flow2Wastewater Quality25 mg/LFree Ammonia15 mg/LOrganic Nitrogen40mg/LTotal Nitrogen200 mg/LTSS200 mg/LBOD5Amount in WaterContaminantSouth Boulder Creek– Stringent Water Quality Standards• Recreational Class 1&2• Cold Water Aquatic Life Class 1&2– High Demand for Water• Numerous Water Rights Diverted Upstream• Low Flow Rates in WinterPrimary Effluent Limits0.23 mg/LNH3—N Tot. Dec.0.0031 mg/LResidual Chlorine67 org/100 mLE. Coli.6.5-8.5pH30 mg/LTSS30 mg/LBOD5LimitParameterAlterative Solutions– Biological Process Options• Trickling Filter• Activated Sludge• Lagoons/Aeration Ponds• Wetlands– Pipeline to City of BoulderTrickling Filter Activated Sludge3Lagoons Wetlands TreatmentPipeline to BoulderAlternativeOperator TrainingLand (acres)Present Value CostEffluent Quality (% BOD removal)Trickling FilterClass C 0.25 $801,568 80%-90%SBR Class B 0.333 $670,402 91%-98%Lagoons Class D 0.5 $946,000 60%-90%WetlandsClass D 1.5$229,000 -$322,00040%-95%PipelineNo special training required4.82 $1,461,700 95%Design Criteria and Constraints– Overall cost (25%)– Process reliability and efficiency (20%)– Additional benefits (20%)– Ease of operation (15%)– Land requirement (10%)– Asthetics/odor (10%)Preliminary Design: Constructed WetlandsInfluent ScreenLagoon Cell 1Lagoon Cell 2Lagoon Cell 3UV disinfectionConstructed Wetlands (3 zones)EffluentSouth BoulderCreek4Pretreatment– 1 bar screen at front of treatment system– Housed in a small shed– Flow meter after bar screen– Must be manually cleaned once a weekLagoons– 2 aerated lagoons, 1 settling lagoon– Design size: 37 x 17.5 meters each–3 meters deep– Flow between lagoons controlled by variable level weir–3rdlagoon has multiple level draw off capabilities to improve suspended solids level– Lined with Geomembrane– Sludge removal required every 10-20 yearsLagoons– 112 - 9 inch air diffuser disks in each of the two aerated lagoons– ~10hp blower assembly required to be housed indoorsMetric Units English Units Orientation ParallelLength8 m 26.25 ft Total # 18Width0.32 m 1.05 ft # in Depth 3Depth.14 m 5.5 in # in Width 6Channel Dimensions Lamp Requirements– How does UV work?– What will the reactor look like?– Additional Considerations?Wetlands Design– Three Zones, Two Parallel Process Trains– Zone 1: • Each Cell 34.5m x 108.8m x 0.5m deep– Zone 2:• Each Cell 13.5m x 30.5m x 1.0m deep– Zone 3:• Each Cell 33.0m x 109.3m x 0.5m deep5Wetlands Design– Total Hydraulic Residence Time: 31.1 d.– Wetland Area: 3.14 Acres– Total Area Approximately 4.6 Acres– Effluent Quality:• BOD<5ppm, TSS<5ppm, NH4<5ppm, TN<10ppm, FC<125org/100mlDesign Specifics31.1 days4.6 acresWetlands15-30 sec.400 ft2UV disinfection*50 days6.1 acresTotal18.6 days1.3 acresLagoonsN/A50 ft2PretreatmentRetention TimeSizeUnit Process*Includes housing for lagoon blowersAncillary Benefits of Wetlands– Recreational/ Educational Opportunities– Wildlife Habitat– Aesthetic Value– Public Opinion (Esp. COB Open Space)– Governor's Office of Energy Management and Conservation RFP = $$Will be Included in Final Report:– Construction staging schedule– Hydraulic Grade Line– Detailed AutoCAD drawings– Finalized cost of