Sustainable Energy Management Approaches in Wastewater Treatment Facilities Preconference Workshop Saturday, October 13, 2007 Color Slides

Energy and Water are … Interdependent Water for Energy and Energy for Water Energy and power production require water: Thermoelectric cooling Hydropower Energy minerals extraction/mining Fuel Production (fossil fuels, H 2, biofuels) Emission control Water production, processing, distribution, and end-use require energy: Pumping Conveyance and Transport Treatment Use conditioning Surface and Ground water Ray Ehrhard, 8:30 AM Water and Energy Interdependence - What are we in for… Where are we going?

Why Do We Care? For wastewater - energy represents 25-30% of the total plant O&M –Raw sewage pumping = 12% –Aeration = 52% –Solid handling = 30% –Lighting, heating, AC, and masc. = 6% Jim Wheeler, 9:25 AM Renewable Energy for the Wastewater Industry: the Office of Water Perspective

Modeling Water Systems Detailed fresh and waste water flows and technologies William Horak, et al 8:50 AM The Energy-Water Nexus (EWN): a New York City Pilot Study

Single Parameter Comparisons Steven Carlson, P.E., 10:30 AM Development of a Utility Energy Index

Katy Hatcher, USEPA Energy Star Focusing on Energy Efficiency for the Drinking Water and Wastewater Industries Portfolio Manager: Facility Summary View

One of NY’s Energy Champions: Albany North WWTP Fine bubble aeration VFDs; SCADA system Enhancement to furnace control; add’l VFDs; add’l premium efficiency motors; building improvements Premium efficiency motors; add’l VFDs Waste heat recovery Kathleen O’Connor, 11:00 AM We’re Here to Serve: How Your State Energy Agency Can Improve Your Bottom Line

Understand Electric Demand Joe Cantwell, 11:00 AM We’re Here to Serve: How Your State Energy Agency Can Improve Your Bottom Line

Energy Efficiency Projects Generally Four Categories Conservation  Less Consumption Efficiency -- Focus on Increasing Equipment & Process Efficiency DO Probes in the ASP Efficient Pumps, Blowers, Motors Replacement of Existing Diffusers with Energy Efficient Membrane Diffusion System Motors with High Efficiency Motors and VFDS Coarse Bubble Diffusers with Fine Bubble Diffusers High Efficiency Motors, Microturbines, and Energy Recovery Systems Primary Treatment Modifications Generation -- Using Waste Fuels DG, Use of Digester Gas for CHP Load Shifting -- Shifting Pumping Load to Off-Peak Hours by Increasing Storage Volume, Pumping Capacity, Installing better pumping controls systems Shahid Chaudhry, 11:00 AM We’re Here to Serve: How Your State Energy Agency Can Improve Your Bottom Line

50% 41% Pumping 25% 42% 17% Aeration Diffuse Electrical energyBiogas energy Sludge dryer Heating boilers Flare Lars Gunnarsson, et al, 2:30 PM Cost effective energy usage at Himmerfjärdsverket sewage treatment plant in Sweden

Tom Jenkins, Vikram Pattarkine, Mike Stenstrom Energy Conservation by Optimizing Aeration Systems Terminology Efficiency –Standard oxygen transfer efficiency (SOTE) (percent oxygen transferred) –Standard oxygen transfer rate (SOTR) (mass transferred per unit time) –Standard aeration efficiency (SAE) (mass transferred per unit time per unit power) All “standard” terminologies defined for clean water such as tap water (secondary process effluent is never suitable for clean water testing) Process Conditions (OTE, OTR, AE) –Adjustment formulas based upon driving force, temperature, barometric pressure, water quality, saturation concentration, etc. –Driving force and water quality the most significant –Driving force = (DO S – DO)/DO S –Water quality – alpha factor, 0 to 1 ! –Total correction can result in process water transfer of only 30 to 80% of clean water transfer

Diffuser Summary Fine pore systems generally, but not always offer the best energy conservation Fine pore systems require a dedication to maintenance; otherwise, select different alternatives Reputable manufactures have valuable experience with piping and assembly – Listen to them! The consultant or process engineer must define the efficiency – Require this information from them! Tom Jenkins, Vikram Pattarkine, Mike Stenstrom Energy Conservation by Optimizing Aeration Systems

Tom Jenkins, Vikram Pattarkine, Mike Stenstrom Energy Conservation by Optimizing Aeration Systems Energy Conservation: Blower Upgrades / Revamps All Blower Types Provide proper maintenance – filters, seals, diffuser cleaning Change to energy efficient motors Add smaller blowers to achieve turndown Combine air use for other functions (Post-Aeration, Channel Aeration, etc.) Update Controls

Tom Jenkins, Vikram Pattarkine, Mike Stenstrom Energy Conservation by Optimizing Aeration Systems Energy Conservation: Control System Techniques All Blower Types Automatic DO Control to match air rates to process demand Use MOV Control to minimize pressure Automatic starting and stopping of blowers Parallel control instead of cascade control Design Control System for Reasonable Payback – 2 to 5 years Include Process Improvement in Evaluation

Robert Ostapczuk, P.E., 3:30 PM Gloversville-Johnstown Joint Wastewater Treatment Facility Energy Conservation Program Case Study Priority 1 Aeration System Improvements Cont’d Overall project cost $1,500,000 Total cost for new blower, Dissolved Oxygen (DO) automatic control, and more efficient diffusers ~ $1,000,000 Energy savings with new system: 30% electricity decline immediately 1.3 M kwh saved annually

Robert Ostapczuk, P.E., 3:30 PM Gloversville-Johnstown Joint Wastewater Treatment Facility Energy Conservation Program Case Study Priority 2 Anaerobic Digester Improvements Biogas Handling Piping –Plugged –Corroded Gas Mixing System –No mixing in Secondary Digester –Poor mixing in Primary Digester Plugged lances Inoperable valves Safety Handling Equipment –Inoperable Flare –Inoperable PRVs

Robert Ostapczuk, P.E., 3:30 PM Gloversville-Johnstown Joint Wastewater Treatment Facility Energy Conservation Program Case Study Priority 2 Anaerobic Digester Improvements Cont’d Secondary Digester Floating Gas Holder Cover –Inoperable –Surface Corrosion Digester Tanks –Never Cleaned Internal Combustion Engine (ICE) Generators –Low electrical output 70% of rated capacity of one unit –High maintenance requirements

Robert Ostapczuk, P.E., 3:30 PM Gloversville-Johnstown Joint Wastewater Treatment Facility Energy Conservation Program Case Study Priority 2 Anaerobic Digester Improvements Cont’d Phase I (2002) –Flushed sediment and scale from biogas piping and existing mixing system –Overhauled ICE generators Phase II (2005) –Converted the existing floating gas holder to a fixed cover with a dual membrane gas holder –Replaced biogas safety equipment Flare Pressure relief valves

Priority 2 Anaerobic Digester Improvements Cont’d Phase II (con’t) –Replaced sediment traps –Replaced DIP biogas piping with SS Replaced gas mixing system with a confined gas mixer in both the primary and secondary digesters Phase III (2006) –90,000 gallon acid whey equalization tank –Acid whey feed system –2-inch Ø HDPE acid whey forcemain Robert Ostapczuk, P.E., 3:30 PM Gloversville-Johnstown Joint Wastewater Treatment Facility Energy Conservation Program Case Study

Engine or Turbine-based CHP Tom Frankiewicz, 9:25 AM CHP for Wastewater Treatment Facilities – where efficiency and renewables meet

Biogas Use: Part of an Integrated Energy System Electricity Heat Gas FuelFuel Recovered Heat Generated Electricity ImportImport ExportExport Plant Demand DigestersDigesters Waste Gas Flares BoilersBoilers Digester Gas Supplemental Heat NaturalGasNaturalGas Effluent Heat Rejection Plant Heat Demand OrganicWasteOrganicWaste Utility Vehicle Fuel Dave Parry, 2:00 PM Renewable Biogas Options

Dave Parry, 2:00 PM Renewable Biogas Options Biogas Treatment Needed for Various Options Iron Sponge Heat Exchange and Separator Blower Activated Carbon Particulate Filter H 2 S Reduction Moisture Reduction Pressure Boosting Siloxane Reduction Particulate Reduction From Digester To Beneficial Use

Point Loma BUDG Schematic Compressed Digester Gas to Truck 3-Stage HP Compressor Feed from PLWTP Gas System Flare 0 psig 5 psig 0 psig 165 psig Blower Pre-PSA Dryer Refrigeration Pressure Swing Absorption (PSA) Dryer 2-StageCompressor Pre-Granular Activated Carbon Refrigeration Granular Activated Carbon Filter Pre- Membrane Heater 150 psig 140 psig 2600 psig C02 Removal Membrane Unit Condensate Return to Wastewater Plant C0 2 Sulfur Removal Fuel Cell Tom Alspaugh, P.E., 3:50 PM Sustainable Energy Management Using In-House Resources

MWWD 30kW Photovoltaic System at MOC III 30 kW rooftop system at MOC III Under directive from Metro Commission, innovative rooftop mounting system and semiconductor technology were chosen Tom Alspaugh, P.E., 3:50 PM Sustainable Energy Management Using In-House Resources