the u.s. epa’s decision support tool for sustainable solid waste management
DESCRIPTION
Susan Thorneloe National Risk Management Research Laboratory Air Pollution Prevention & Control Division Research Triangle Park, North Carolina LCA and Integrated Waste Management Prague, Czech Republic April 13, 2004. - PowerPoint PPT PresentationTRANSCRIPT
Susan ThorneloeNational Risk Management Research Laboratory
Air Pollution Prevention & Control DivisionResearch Triangle Park, North Carolina
LCA and Integrated Waste ManagementPrague, Czech Republic
April 13, 2004
The U.S. EPA’s Decision Support Tool for Sustainable
Solid Waste Management
What We’ll Cover Today . . .
• Background Waste Management in
the U.S. Decision Support Tool
• Case Studies• Next steps• Summary
Solid Waste Management in the United States
• Prior to the 1970s Sanitary landfills were rare Wastes were dumped and burned to reduce volume Incinerators had no pollution control or energy recovery
• Today More integrated and complex approaches “Waste-to-energy” facilities with minimal environmental
burden “Sanitary” landfills
• Requirements for design, operation, and monitoring• Large landfills are required to collect and control landfill gas• Different approaches being evaluated including allowing leachate
recirculation and other liquid additions
050
100150200250
Million Metric Tons
1974 1980 1990 Today
U.S. Municipal Waste Management
Recycling
Combustion
Landfilling
Decision Support Tool
Purpose: To assist solid waste managers in determining optimal waste
management strategies that minimize total cost and environmental burdens
Decision Support Tool for Sustainable Solid Waste
Management • Communities requested
planning tool that Considers site-specific factors,
data, and concerns Is flexible and can consider
different needs for• Rural and urban areas• Residential and commercial waste
Considers costs and environmental tradeoffs
What is the Municipal Solid Waste Decision Support Tool?
• A computer-based tool to assist solid waste managers in determining optimal waste management strategies that minimize cost and environmental burdens.
• Components of the MSW-DST include:– Process models (MS Excel)– Mass flow model– Optimization routine (Cplex)– User interface (MS Visual Basic)
System Boundaries
MSW MANAGEMENT ACTIVITIES
kWh Gas Steam Compost Recyclables
MunicipalSolid Waste
Energy Materials
Collection
Combustion
Compost
MaterialsRecovery
Landfill
WaterReleases
Materials andEnergy Offsets
AirEmissions
SolidWaste
Waste is generated by residential, multifamily, and commercial sectors and collected and transported
for separation and recycling, combustion, composting, and/or landfilling. These activities consume
energy and materials and result in environmental burdens. Any materials or energy that are recovered
may create offsets of virgin materials in the manufacturing and energy sectors.
Life-Cycle Analysis of GHG Emissions
MSW Flow
Collection
Material Recovery Facility
Waste-to-Energy Combustor
Landfill
Refuse DerivedFuel
Compost
Remanufacturing
Transfer Station
Transfer Station
Transfer Station
Transfer Station
Transfer Station
Residue
Input site-specific data in Process models
Optimization Module
Alternative Strategies
Requirements: - Mass - Regulations - Targets
USER
Cost & Life-Cycle Inventory Coefficients
MSW-DST Framework
Emphasis• Sound science producing results which
are credible and objective• Close interaction with all stakeholders
and rigorous review process• Providing more holistic approach
consistent with EPA’s emphasis on cleaner, cheaper, and smarter environmental management
Complex Solid Waste Decisions Being Evaluated
How do we ensure
• Cost efficient waste management?
• Meeting state mandated recycling goals?
• Continued improvement of the environment?
• Fast, objective analysis of options?
Environmental Aspects• Impact to water sheds and air
quality • Energy consumption and offsets• Benefits from materials
recycling
Economic/Social Aspects• Municipal budgets• Need for new facilities• Household convenience
Results =•Good Science•Cost Savings•Environmental Improvement•Sustainable Solutions
Identified as one of the most
important new developments in
U.S. waste management for the
21st Century
MSW DST Case Studies
• Anderson County, South Carolina
• Atlanta, Georgia• Great River Regional
Waste Authority, Iowa• Lucas County, Ohio• Madison, Wisconsin• Minneapolis, Minnesota• Portland, Oregon• Wake County, North
Carolina• Seattle, Washington
• Spokane, Washington• State of California • State of Georgia• State of Washington• State of Wisconsin (update)• Subbor – ETV GHG Center• U.S. Conference of Mayors –
U.S. GHG Study• U.S. Navy Region Northwest• Vancouver, British Columbia
Four Case Studies• St. Paul, Minnesota• State of Washington (Comparing
two urban and two rural regions)• EPA’s New Research Facility• U.S. Study on Trends in
Greenhouse Gases & Solid Waste Management
• Other Studies
St. Paul, Minnesota
• Comparison of composting of biodegradable waste versus waste-to-energy and landfilling
Comparison of Annual Cost
0
1
2
3
4
5
6
Million U.S.
Dollars
Landfilling Waste-to-Energy
Composting
Comparison of Annual Energy Usage (MBTU)
-80,000
-60,000
-40,000
-20,000
0
20,000
40,000
Landfill WTE Compost
Comparison of Annual Tons of Greenhouse Gases
-3,000
-2,500
-2,000
-1,500
-1,000
-500
0
500
1,000
1,500
2,000
Landfill WTE Compost
Carbon
Equivalents
State of Washington• Goal was to
compare residential curbside collection and recycling to landfilling and Waste-to-Energy for two urban and two rural regions
Comparison of Annual Cost for Urban-West
40
42
44
46
48
50
52
Million U.S.
Dollars
Urban-WestRecycling
Urban-WestLandfilling
Comparison of Energy Conserved versus Energy Used for Recycling
0
5
10
15
20
25
30
35
40
45
Urban West Urban East Rural West Rural East
Mon
thly
kW
h pe
r Hou
seho
ld
RecyclingEnergy Used
UpstreamEnergyConserved
Urban West Region – Annual Energy Use (MBTU)
-3,000,000
-2,500,000
-2,000,000
-1,500,000
-1,000,000
-500,000
0
500,000
UW - Recycling UW - Landfill
Urban West Region – SOx Emissions (kg/yr)
-2,000,000-1,800,000-1,600,000-1,400,000-1,200,000-1,000,000
-800,000-600,000-400,000-200,000
0200,000
UW - Recycling UW - Landfill
Urban East Region - Annual Cost
10,000,000
10,500,000
11,000,000
11,500,000
12,000,000
12,500,000
UE - Recycling UE - WTE
Urban East Region – Annual Energy Use (MBTU)
-300,000
-250,000
-200,000
-150,000
-100,000
-50,000
0
UE - Recycling UE - WTE
Urban East Region – SOx Emissions (kg/yr)
-300,000
-250,000
-200,000
-150,000
-100,000
-50,000
0
UE - Recycling UE - WTE
Application to EPA’s New Facility in the Research
Triangle Park, North Carolina• Comparison of composting
versus landfilling of non-recycled biodegradable waste
• Facility houses 2,200 people, 400 labs, conference center, cafeteria, national computer center, and childcare center
Scenarios Evaluated Scenarios: 1. Collection, transfer station, and
long haul to regional landfill ~145 km from EPA
2. Collection/transport to compost facility ~ 96 km from EPA
3. Collection/transport to site ~2 km from EPA
Organic Waste Generated: ~160 tonnes of organic
waste including food and yard waste, mixed paper, and animal bedding
Annual Dollar Cost
0
5,000
10,000
15,000
20,000
25,000
30,000
Landfill Compost - Onsite Compost - Offsite
Carbon Equivalents (tons/yr)
0
2
4
6
8
10
12
Landfill Compost - Onsite Compost - Offsite
Annual Energy Use (MBTU)
0
50
100
150
200
250
Landfill Compost - Onsite Compost - Offsite
Particulate Matter (kg/yr)
0
2
4
6
8
10
12
14
Landfill Compost - Onsite Compost - Offsite
Findings from MSW-DST Scenario 1 (landfill option) is highest
emitter of greenhouse gases due to• fugitive landfill methane and • collected gas is flared (no energy
recovery; no offsets for fossil fuel conservation)
Scenario 2 (composting off-site) is least energy efficient due to
• long hauling distance and• Inefficient transport of waste
Scenario 3 (compost on-site) is most desirable option and discussions are underway to identify/develop near-by facility for future use
Evaluation of GHG Emissions Over Time from Solid Waste
Management in the U.S.• Study conducted for U.S. Conference of
Mayors to determine trends in GHG emissions comparing waste management practices over time
• Compared actual GHG emissions today versus what would be emitted if 1970s waste management practices still existed
Analysis of Trends in Greenhouse Gas Emissions for U.S. Solid
Waste Management
1974
2000 2000 with 1974
Technology Waste Management Technology MMTCE/year MMTCE/year MMTCE/year
Collection/Transportation 0.53 0.92 0.77 Recycling -1.1 -6.7 -2.6 Waste-To-Energy -4.9 Landfilling 36 21 53 Total 35 10 51
Net GHG Emissions in the U.S.
0.00E+00
1.00E+07
2.00E+07
3.00E+07
4.00E+07
5.00E+07
6.00E+07
1970 1975 1980 1985 1990 1995 2000
Year
Met
ric T
ons
Car
bon
Equi
vale
nts
(MTC
E)
Net GHG Emissions
Actual Integrated Waste Management Technology path
41 MMTCE avoided
1974 Technology path
Recycling
-8.00E+06
-7.00E+06
-6.00E+06
-5.00E+06
-4.00E+06
-3.00E+06
-2.00E+06
-1.00E+06
0.00E+001970 1975 1980 1985 1990 1995 2000
Met
ric T
ons
Car
bon
Equi
vale
nts
(MTC
E)
GHG Emissions from Recycling
Actual Integrated Waste Management Technology path
4 MMCE avoided
1974 Technology path
Year
Landfills
0.00E+00
1.00E+07
2.00E+07
3.00E+07
4.00E+07
5.00E+07
6.00E+07
1970 1975 1980 1985 1990 1995 2000
Year
Met
ric T
ons
Car
bon
Equi
vale
nts
(MTC
E)
GHG Emissions from Landfills
Actual Integrated Waste Management Technology path
32 MMTCE avoided
1974 Technology path
Waste-To-Energy
GHG Emissions from Waste-to-Energy
-6.00E+06
-5.00E+06
-4.00E+06
-3.00E+06
-2.00E+06
-1.00E+06
0.00E+00 1970 1975 1980 1985 1990 1995 2000
Year
Met
ric T
ons
Car
bon
Equi
vale
nts
(MTC
E)
GHG Emissions from Waste-to-Energy
Actual Integrated Waste Management Technology path
5 MMTCE avoided
1974 Technology path
Note: Negative emissions indicate "savings" in emissions due to energy recovery
U.S. GHG Emissions Avoided
(Year 2000)
Increasing Recycling
Increasing Waste-to-Energy
Increasing Landfill Gas Controls and Waste Diversion
TOTAL AVOIDED
4 MMTCE
5 MMTCE
32 MMTCE
41 MMTCE
Other Ongoing Studies
• RTI is conducting study for State of California comparing “waste conversion” technologies to recycling, landfilling and waste-to-energy
Waste Conversion for BioenergyRenewable Syngas from Biomass Residuals
Tipping Floor Autoclave Recyclables Recovery
ElectricalGeneration
Gasifier
MixedMSW
OrganicPulp
Other Ongoing Studies
Understanding benefits and impacts of Expanding or cutting back recycling
programs (including curbside recycling program and identification of what to include)
Long haul of waste to large regional landfills Existing programs and opportunities for
reducing costs and environmental burdens
Next Steps• Developing web-accessible version of the
MSW-DST• Updating emission factors for landfills• Finalizing partnerships in ensuring he integrity
of MSW-DST is maintained over time• Providing training and technical support to
user community• Release of final project report and journal
articles providing results of case studies
Contacts
Project Web Site – www.rti.org(Search under Municipal Solid Waste)
Keith WeitzResearch Triangle Institute
Susan ThorneloeU.S. Environmental Protection Agency
Summary• Computer-based version of the
tool is available for use through RTI
• Work underway to develop web-accessible version of the tool
• Over 30 studies conducted to date and this number will significantly increase once web-accessible version of the tool is available
• We think that significant costs and environmental improvements can be found through taking a holistic approach to environmental management