Getting to Zero: Sustainability Best Practices at POTWs Presentation Outline Sustainability at POTWs What are GHGs? Mike Falk, PhD, PE HDR Engineering, Inc. Dave Reardon, PE, ENV HDR Engineering, Inc. How to Reduce GHGs Your Take Away Points Impact of Future Regs To Be Truly Sustainable, You Want to Optimize Plant Inputs/Outputs Today, Let s Focus on GHGs Energy (Electricity, Gas, Fuels) Air Emissions Energy (Electricity, Gas, Fuels) Air Emissions Chemicals Biosolids Various Supplies Raw Sewage, FOG, Septage, Food Waste Solid Waste Treated Effluent Renewable Resources Raw Sewage, FOG, Septage, Food Waste 1
Oh Yeah How Can Your Plant Reduce GHGs? Some Plants Take Energy and GHG Reduction to the Extreme! Process Selection Has a Profound Impact on Energy/Sustainability 6,000 Energy Intensity (kwh/mg) 5,000 4,000 3,000 2,000 1,000 Strass Wastewater Treatment Plant, Austria 0 Conventional Activated Sludge Conventional Activated Sludge with Nitrification- Denitrification Membrane Bioreactor (MBR) 2
Here s How We Get to Zero Energy and Reduce GHGs First and Foremost, You Will Need Anaerobic Digestion of Biosolids Contribution % of Plant Power 100 90 80 70 60 50 40 30 Gap: 11% Solar, Wind, More FOG, or Food Waste, Carbon Credits Sidestream Treatment 8% 6% Resolve Optimize Primary Clarifier 5% Overdesign 8% 25% 6% Precondition WAS 4% Acid Phase Digestion Fuel Cell Cogeneration FOG (Fats, Oil, and Grease) and Food Waste Digestion 20 10 30% Conventional Cogeneration (Engines) Energy Reduction or Energy Production Ideas Egg-Shaped Digesters Conventional Digesters Improving Primary Clarifier Performance Can Make A Difference Condition Solids Prior to Digestion Improved hydraulics can improve TSS removal ~10% SS = BOD = Energy in activated sludge process What about a technology to replace Primaries! What Would Happen if We Removed 95% of SS Prior to Aeration? The Wastewater Treatment Holy Grail: WAS Cell Walls Destruction 3
Oh, These Poor Bugs! But Wait! There is No Free Lunch Heat Pressure Freezing All WAS pretreatment systems use electricity, and sometimes gobs of it Electricity Mechanical Abrasion Cell Vacuum Ultrasonic Some may use chemicals Mechanical complexity (O&M) Performance claims verification Despite Historically Mixed Results.Technologies are Improving! Piloting is Needed for Feasibility Analysis Co Digestion is the 800 lb Gorilla in the Room FOG and Food Waste FOG Digestion & Food Waste Can Increase Digester Gas by 50 200% FOG Virtually 100% volatile solids destruction Highly degradable Relatively easy to accept, process, and find Very small increase in biosolids production May improve volatile destruction of primary/was Food Waste Significant challenges 4
Proper Sizing of Equipment Produces Large Energy Savings Side Stream Treatment (Digester Centrate/Filtrate) Saves Energy & GHGs Sidestreams are a high source of ammonia Pumps 100% reduction in carbon source required Small footprint 50% reduction in energy Blowers Anammox Reactor PV = $4,500/kW Photovoltaic (PV) and Wind Renewable Energy 1 MW PV systems are common They Are Good Prospects for Performance Contracting Your Take Away Points Net Zero GHG plants are possible Process selection greatly impacts GHGs The plant of the future will remove much more carbon prior to aeration You probably have to cheat to achieve Net Zero GHGs (FOG, Food Waste, PV, wind) Are you performing sustainability reviews for your planning and design efforts Don't overdesign Future regulations will increase GHGs Everything adds up 5
Not So Fast Future Regs Can Impact GHG Emissions Sustainability WERF Report There are Evil Forces at Work!!! Current Regulatory Trends Drive Increasingly Stringent Discharge Limits Ensuring Clean Water for California 21 Falk, M.W., Neethling, J.B., Reardon, D.J. (2011) Striking the Balance between Nutrient Removal and Sustainability, WERF Report NUTR106n CO 2 eq mt/yr 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 0-2,000 And Things Are Getting Worse for Nutrient Removal (10 mgd plant) Getting to Zero: Sustainability Best Practices at POTWs Mike Falk, PhD, PE HDR Engineering, Inc. Dave Reardon, PE, ENV HDR Engineering, Inc. Falk, M.W., Neethling, J.B., Reardon, D.J. (2011) Striking the Balance between Nutrient Removal and Sustainability, WERF Report NUTR106n 6
The Path to Net Zero Water: San Ysidro US Land Port of Entry Andy Frichtl, PE, LEED AP Mechanical Engineer, Interface Engineering Ben Dalton, LEED AP Architect, Miller Hull Partnership Andrew Frichtl, PE, LEED AP» 20+ years of experience in energy and water conservation» Directs the design of the mechanical and electrical systems that offer efficient payback time frames» Involved in design and commissioning of 50+ high performance buildings» Speaks frequently at national and regional conferences:» Designing to Meet the 2030 Challenge, 2010 Vancouver AIA Chapter» The Art and Science of Net Zero, 2009 AIA National Conference and 2007 Greenbuild Ben Dalton, LEED AP» 10+ years experience in architecture and sustainable building design» Lead Project Manager for the San Diego office, Miller Hull Partnership, LLP» Lecturer: Digital Design & Manufacturing in Architecture at the University of Washington 2006 2010» Skilled at parametric modeling to evaluate system performance 2/3 of the surface of the earth is covered by water. 7
Water access: High areas of volume demand do not always align with areas of high volume and reliable supply. If all earth s water fit in a gallon jug, available fresh water would equal just over a tablespoon less than half of one percent of the total. Approximately 1 million miles of pipelines and aqueducts carry water in the U.S. & Canada. That's enough pipe to circle the earth 40 times. The 2009 ASCE Report Card on our nation s infrastructure gave water & wastewater systems a D and estimated the five year funding requirements for necessary upgrades at $255 billion. 8
San Diego in the highest tier of rate increases in the country. 2010 (USA Today 2012) USA Today (Increases over the last 12 years) Site located near the mouth of the Tijuana River and within the Tijuana River Watershed SYLPOE SYLPOE Site located near the mouth of the Tijuana River and within the Tijuana River Watershed Site located near the mouth of the Tijuana River and within the Tijuana River Watershed 9
Project site ~ 40 Acres but our influence is closer to 284 Acres SYLPOE SITE 232 acres Thru Capture and Reuse and Bioretention planters the Port of Future targets Net Zero Runoff 52 acres (Energy Independence & Security Act) SECURITY & RESPONSIBILITY COST SUPPLY NEIGHBORS & ENVIRONMENT 10
San Ysidro US Land Port of Entry 31 LANES 53 LANES 11
CONSERVE 7 NET ZERO WATER COLLECT (8.44 ACRES) INFILTRATE 12
4.29 NET ZERO WATER 4.29 1.23 NET ZERO WATER 4.29 1.23 6.20 South Bay Water Reclamation Plant 2.25 miles away City of San Diego Parks and the Community SYLPOE Site Connection 13
STRATEGY Rainwater condensate blackwater credit: Steve Moddemeyer, Collins Woerman Conventional Efficient Low-Flow Condensate Rainwater Irrigation Fixtures Recovery Harvesting at Cistern 40 YEAR COST SAVINGS: $3.6 MILLION Membrane Bio-Reactor HEADHOUSE HH Membrane Bioreactor System» Small footprint and scalable compact odor free system fits into virtually any location» Produces high quality effluent at all times for direct, non potable reuse or discharge» Automated operation minimizes operator intervention HEADHOUSE HH Membrane Bioreactor System 14
Head House Level 0 MBR Process Flow Diagram Head House Level 0 MBR Process Rainwater / Blackwater Plant HH-P301 15
Integration of HVAC System HEADHOUSE CUP Chilled Water System Integration HEADHOUSE CUP Heating Water System Integration ESCALATION RATE Water / Sewer Costs Sewer/Water Historic Rate Increases City of San Diego 16
Bioprocess MBR Life Cycle Cost (Non Integrated) Bioprocess MBR Life Cycle Cost (Integrated) Cooling energy savings» Reject 50% of cooling loop heat to nonpotable water instead of cooling tower or ground loop Net Zero WWTP Energy» (30kW)*(4,000 hrs) = 120,000 kwh/yr 100000 DHW energy savings» Preheat 30% of DHW energy» (2,000 GPD)*(90 F 70 F)*(8.33 lb/gal)*(365 days/yr)*(0.000293 kwh/btu) = 35,700 kwh/yr Heating energy savings» Gain 10 F heat pump approach (80 F vs. 70 F) vs. ground loop» 1 COP gain for 40% of heating needs = 22,000 kwh/yr Annual Energy (kwh) 50000 0 50000 100000 79800 120000 35700 22000 97900 Consumption Savings Total energy savings = 178,000 kwh/yr 150000 MBR Energy Usage Cooling Energy Savings DHW Savings Heating Savings Net Savings 17
Result Summary» Net Zero nonpotable water» Net Zero waste water» Net Zero carbon WWTP» 40 year LCC savings: $3.6 Million USD 18