2010
NW Biosolids Management Conference
Lake Chelan, WA
SUSTAINABILITY TRIFECTA:
At The Plant
Overview
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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
Energy Independence - Solar
Solar Site Conditions
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Available space
Grade/slope
Soil type(s)
Access
Security
Interconnect
Shade
Zoning
Height limits
Building codes
Building permits
Review timeline
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
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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
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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
Heater tubes
Swash Plate
Drive
Cooler
Combustor
Piston
Regenerator
Energy Independence - Biomass
Stirling BioPower 55kW demonstration Unit
Energy Independence - Biomass
• 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
Energy Independence - Biomass
• 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
Energy Independence - Biomass
• 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
Resource Recovery - Nutrients
• 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
Resource Recovery - Nutrients
• 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.
60%
50%
40%
Strongly agree
Agree
Neutral
Disagree
Strongly disagree
30%
20%
10%
0%
Support if
cheaper
Support if more
Support
sustainable drinking water
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 capital cost:
$13.2 million
• 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
• Estimated capital cost:
$40.1 million
• 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
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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
dan.hanthorn@ci.corvallis.or.us