2010 NW Biosolids Management Conference Lake Chelan, WA SUSTAINABILITY TRIFECTA: At The Plant

2010NW Biosolids Management Conference

Lake Chelan, WA

SUSTAINABILITY TRIFECTA:At The Plant

Overview

• Wastewater - Pivotal Times

• Corvallis – Place

• Energy Independence

• Resource Recovery

• Recycled Water

• Wastewater’s Future Is Now

• Over the Horizon

Pivotal Times

• Chapter 1 - Basic conveyance

• Chapter 2 - Protection of human health

• Chapter 3 - Environmental protection

• Chapter 4 - Recycling and resource recovery

Corvallis - Place

• Located in Oregon’s mid-Willamette Valley

• Compact community of 55,000

• The economy is dominated by Oregon State University and high tech industry

• Government and commercial hub of Benton County

• The WWRP produces 4 billion gallons of treated wastewater per year

• WWRP Annual Energy Usage 3,766 MWh

• WWRP Peak Energy Demand 1,372 kW

• Strong sustainability ethic

Corvallis – Sustainability

• Community focus on sustainability

• Sustainability efforts in conservation, recycling and resource recovery at the Wastewater Reclamation Plant

• Energy Independence Efforts

• Resource Recovery Initiative

• Recycled Water Plans

Energy Independence – First Steps

• Energy Conservation

• Cheapest and easiest path to reduced energy consumption

• Seven energy audit performed

• The last two audits provided no recommended actions

• Process optimization

• Trickling filter series operation for BNR• Ammonia reduction of 70% at 7 MGD with 60 hp aeration

blower

• Improved instrumentation• Reduced consumption of sodium hypochlorite and sodium

bisulfite by 40%

Energy Independence – Solar

• A 2 Mw “peak” solar array will provide 55% of current WWRP power needs

• Located on adjacent prior converted wetlands, land locked by rail roads

• Third-party developer designs, builds, owns, operates and finances the solar power facilities under a 30-year Power Purchase Agreement

• Project under contract, pending a net metering agreement with the utility and investor recruitment by the developer

Solar Site Conditions

• Available space• Grade/slope• Soil type(s)• Access• Security• Interconnect• Shade• Zoning• Height limits• Building codes• Building permits• Review timeline

Energy Independence - Solar

Energy Independence - Biomass• The typical scenario for a successful, long-term

municipal co-gen program includes a population base of 200,000 or more, supporting 500kW or more of generation capacity.

• Corvallis baseline condition - biogas at typical conversion efficiencies will support 150kW of generation capacity

• Do we adapt vs. do we grow

• Stirling-cycle engine technology

• Import biomass to support 500kW• Crude Glycerol

• Fats, Oils & Grease

• Food waste

• Algae

Energy Independence - Biomass

• Stirling cycle engine technology first used in 1778

• External combustion engine

• Working gas is heated and expanded to drive pistons

• The working gas is recycled and used over and over

Energy Independence - Biomass• Stirling BioPower 55kW demonstration project

• Validate low O&M expense and waste heat

• Efficiency – 30% net electrical, 80% CHP efficiency

• Noise level - 58 dBA @ 20’

• Emissions – CARB ultra-low compliant

Swash PlateDrive

Piston Regenerator

Combustor

Heater tubes

Cooler


Stirling BioPower 55kW demonstration Unit


• Imported Crude Glycerol

• Co-produced with

biodiesel

• High strength – 1 to

1.8 million COD

• Readily digestible

• 250 gallons or 20% additional COD has increased gas production 25%

• Potential for reduced volume of biosolids


• Algae

• OSU Sun Grant and BioAlgene

• 130,000 species of algae

• Identifying compatible species for closed and open grow systems

• Co-gen flu gas

increases growth rate

4x to 5 x

• Harvest 240 dry

tons/yr of algae paste

for digestion


• Imported FOG waste

• Regulations have increase the rate of recovery

• Growing industry based on collection, hauling and processing of FOG to energy

• Imported Food waste

• OSU Food Services

• Regional hospital

• Food manufacturing waste

Resource Recovery - Nutrients

• Biosolids Lagoon overflow high in ammonia (1,000 mg/L) and phosphorus

• Landfill leachate high in ammonia (1,000 mg/L) and magnesium; accepted at 1% of WWRP flow


• 80%+ ammonia removal in < 10 minutes

• Flash Vacuum Distillation

• Atomizer

• Low Vacuum

• Temperature and pH adjustment

• Partial pressures to separate materials

• Heat recovery to increase efficiency


• CASTion R-cast process to produce struvite crystals and 30% liquid ammonium sulfate

• 90% nutrient recovery

• Reduces nutrient load to WWRP by 811 tons per year

• Fertilizer wholesaled to local ag distributor

• Low-cost approach to permit compliance at 5 mg/L ammonia

Recycled Water

• Community survey by OSU

• Survey results were surprising

• Recycling reduces the incentive to conserve!

• If someone else wants this water, maybe we should keep it for ourselves!

• High acceptance of “flowers to showers”!

• Three alternatives now under consideration

Acceptance of water reuse if it is cheaper or more sustainable than discharging into the river, and acceptance of turning reclaimed water into drinking water if regulations allowed it.

North Alternative

• Agricultural irrigation on grass seed and other crops

• Constructed polishing wetlands adjacent to river

• Willamette River subsurface discharge

• Estimated capital cost: $24.1 million

• 20-year lifecycle cost: $25.9 million

▼ Est. Carbon Footprint: 130 Metric Tons CO2/Year

East Alternative

• Irrigate Trysting Tree Golf Course

• Constructed polishing wetlands (Berg Park)

• Restricted impoundment discharge (Knife River Pond)


• Estimated 20-year lifecycle cost: $14.9 million

• Est. Carbon Footprint: 130 Metric Tons CO2/Year

South Alternative

• Agriculture (Greenberry Irrigation District)

• Construct polishing wetlands next to Finley

• Muddy Creek flow augmentation


• 20-year lifecycle cost: $45.6 million

• Est. Carbon Footprint: 580 Metric Tons CO2/Year

Recycled Water• Current regulations reflect our attitude towards water

• Water is abundant enough and affordable enough – for now

• Widespread reuse of water will happen in the U.S.

• Typical path to reuse – water crisis

• Alternate path to reuse – cost

• The criteria for each approach to reuse is the same :

• Treatment technology

• Social acceptance and economic challenges

• Sustainably implemented

• Risk management and validation

Wastewater’s Future Is Now

• Emphasis on recycling and resource recovery• Redefined concepts of “wastewater” and “treatment”• Redefined roles for operators and managers• We are the liquid waste treatment experts• We have the technology, infrastructure and the franchise• Sustainably reprocess 100% of the resources that are

imported or come down the pipe• Clean water will become a byproduct of resource recovery• Analogy to solid waste field

Over The Horizon

• A one-step wastewater-to-drinking water process and

net-energy producer• Forward osmosis• Low reject rate• High-rate, dilute digestion of reject stream with co-gen• Small footprint and low power requirement

• A single step, continuous, real-time, multi-parameter, optical laboratory processing multiple sample streams• COD, BOD, cBOD, E.coli, NH3, NO3, turbidity, Cl2, TSS,

PO4, UV transmittance• No preservation, chain of custody, lab consumables;

fewer field elements and lab instruments

Questions?

Dan Hanthorn

Wastewater Operations Supervisor

City of Corvallis

PO Box 1083

Corvallis, OR 97339

(541) 754-1757

[email protected]

Documents

2010 NW Biosolids Management Conference Lake Chelan, WA SUSTAINABILITY TRIFECTA: At The Plant