WEF SDC 2011 Expansion of Acton WWTP University of Guelph Team: Alexandra Chan Adam Erb Cynthia Mason Julia Veerman October 16, 2011

Outline  Introduction  Population Analysis  Process Selection  Phase 1 Design  Modeling  Noise & Odour Control  Construction  Phase 2 Design  Economic Evaluation  Conclusions and Recommendations

Review of Existing Facility

Problem Statement  Current WWTP operating near peak capacity  Need to increase capacity to accommodate projected growth in two phases  Meet projected effluent criteria

ParameterCurrent (m 3 /day) Phase 1 Given (m 3 /day) Phase 2 Given (m 3 /day) Average Daily Flow (dry weather) Maximum Daily Flow (dry weather) Instantaneous Peak Flow (wet weather) Design Basis ParameterExisting Effluent Objective/Limit Proposed Effluent Objective/Limit BOD 5 (mg/L)2/5 TSS (mg/L)3/5 Total Phosphorus (mg/L)0.2/0.30.1/0.2 (Ammonia + Ammonium) Nitrogen (mg/L) Non-freezing period (May 1 to Nov 31) Freezing period (Dec 1 to April 30) 1.0/ / / /4.0 Unionized Ammonia (monthly average) (mg/L) Unionized Ammonia (any single sample) (mg/L) - -/0.1 -/ /0.08 Escherichia Coli (monthly geometric mean density) (#of organisms/100mL) 100/150

 Predicted linear growth  Assumed water saving devices at 10%  Infiltration/Inflow at 204 L/c/d Population Analysis ParameterCurrentPhase 1 Given Phase 1 Calculated Phase 2 Given Phase 2 Calculated ADF MDF Peak

Process Selection  Constraints  Accommodate design flows  Meet effluent discharge limits  Use available land  Be compatible with existing facility  Criteria  Cost effectiveness  Integration with existing facility  Environmental impact and footprint minimization

Phase 1 Design

Process Flow

Primary Clarifier

 Add two rectangular clarifiers  New volume 256 m 3  ADF SOR of 27.5 m 3 /m 2 /day  Maximum day flow  62.5% TSS removal  40.3% BOD removal  Chain & scraper sludge collector and scum removal system Primary Clarifier

Secondary Treatment

 Two conventional plug flow activated ‐ sludge system with nitrification  Accommodate 1275 m 3 /d required  Target MLSS = 4000 mg/L  SRT = 12 days  Fine bubble aeration  Positive displacement blower  Designed for max day flow + additional feedback flow Aeration System

 Two additional secondary clarifiers  Limiting solid flux concept  MLSS = 6620 mg/L  Overflow = 31 m 3 /m 2 d  Chain & scraper sludge collector and scum removal system  Max day flow design Secondary Clarifier

Tertiary Treatment

 85 mg/L liquid alum with 45% purity – 824 kg/d  Addition point in activated sludge tank Chemical Addition

 Dual media deep bed filtration  Existing filters work well to meet limits  Widely accepted in WWT  Easily retrofit  Leopold™ Type S™ Underdrain  Air scour + surface wash backwash  Max day flow design with one filter out of commission  SLR of 7.2 m 3 /m 2 /h Filtration

 UV selected as best disinfection method  Trojan UV3000Plus™ system  LP/HI lamp  Automatic and continuous dose pacing  Automated mechanical/chemical cleaning  Automatic level controller  Sized for peak flow UV Disinfection

Solids Handling

 Sequential dual-stage digester series  Add new series in parallel  Methane gas collected for heating  Thermophillic Stage 1  SRT 2 days  Recirculation pump mixing  Mesophillic Stage 2  SRT 8 days Bio-Solids Digester

 Belt press drying after digester  Polymer addition  Increases solids concentration from ~3% to ~25%  Cost-effective in disposal  Reduces footprint Sludge Drying

Mass Balance

System Controls and Instrumentation  Control strategy  Increased control and monitoring  Small relative capital cost  Significant efficiency improvements  Biological treatment  Aeration accounts for up to 50% energy consumption  Matched oxygen demand profile  Intelligent feedback control for aeration, RAS, WAS

 Clarifiers  Monitoring  Sludge pumping control mechanisms  Digesters  Control for feeding rates, recirculation, heating, withdrawal  Tertiary Treatment  Flow splitting  SCADA  Interfacing with SCADA for remote monitoring System Controls and Instrumentation

Hydraulic Profile

 Projected peak influent concentrations and flows  Proposed plant sizing  Clarifier modeling based on Lessard and Beck dynamic model  Activated sludge modeling completed using the IAWQ1 model Phase 1 – Model Inputs

 BOD and NH3 water quality requirements met  Model Shortcomings:  Chemical phosphorous treatment or tertiary filtration not accounted for Phase 1 – Model Results

 Currently no odour or noise issues  Reduce odour and noise  Buffer zone  Housing potential equipment Odour and Noise Control

 Completion in 24 months  Best management practices:  Construct in phases  Protect waterways  Provide training  Conduct inspections Construction

Phase 2 Conceptual Design

 Modify Plant B aeration basin configuration to plug flow + BNR  Investigate:  Membrane technology  Phosphorus extraction Phase 2 Conceptual Design

Total Capital Cost Estimate = $24M Phase 1 – Capital Cost

Annual O&M Cost Estimate = $1.2M Phase 1 – O&M Cost

Total Capital Cost Estimate = $12M Phase 2 – Capital Cost

 Expansion design to increase the Acton WWTP capacity  Preliminary Phase 1 design  Additional clarifier, disinfection, and anaerobic digestion trains  CAS + nitrification  Deep bed dual media filter  Belt press  Conceptual Phase 2 design Conclusions

 Implement sewer system improvement plan  Conduct more simulations  Obtain more cost-specific information from manufacturers  Conduct pilot tests Recommendations

Dr. Hongde Zhou, P.Eng., University of Guelph – Faculty Advisor David Arsenault, P.Eng., CH2M Hill – Consulting Advisor Rafiq Qutub, P.Eng., WEAO – SDC Sub- Committee Chair Lauren Zuravnsky, P.E., WEF – Design Competition Sub-Committee Chair Acknowledgements