scope 3 greenhouse gas inventory - unc institute for the...

Scope 3 Greenhouse Gas Inventoryfor the Town of Chapel Hill

Daniel Band

David Bellard

Briana Duggan

Faisal Hussain

K. Amanda Saunders

Katie Williams

Emissions Inventory Outline

Emissions Scopes

A Method for Classifying

And Measuring GHGs

Scope 1

Direct emissions from on-site

energy production

Examples: fleet vehicles,

generators, transit system

Scope 2

Emissions from energy purchased

through an off-site producer

Examples: Electricity usage

Scope 3

Emissions indirectly resulting from

Institutional operations

Examples: Employee commuting,

solid waste, water treatment and

distribution, employee travel,

landscaping, and more

The Focus of This Project

• Scope 3 Emissions

• Specifically, we looked at:– Employee Commuting

– Solid Waste

– Water Distribution and Treatment

• We also examined transit emissions credits

Employee Commuting

Step 1: Geocoding Employee Addresses

Step 2: Match Addresses with Workplaces

1. Geocoded Town workplaces

2.Combined employee addresses to workplaces based on department

3.Ran best-route analysis from each address to their workplace

Figuring Out Total Employee Commuting Miles (ECM)

Statistics Derived from Analysis:

Average One-Way

Commute

12.3 miles

Avg. Commute per Day 24.6 miles

Employee Commuting

Miles per Day20,116 miles

Employee Commuting

Miles per Year4,827,840

miles

Accounting for the 180 unmatched addresses

180 employees x 24.6 miles = 4421 miles

20,117 (ecm) x 240 working days/year =

4,827,840 employee commuting miles per year

Taking into Account Alternative Transportation

Town commuting survey data:

• 656 employees drive alone

• 28 carpool

• 14 bike

• 14 walk

• 7 take public transit92%

4%

2%2%

1%

Employee Commuting Habits

Drives Alone

Carpools

Bikes

Walks

Public Transit

• Emissions saved by alternatives:

4,827,840 miles (rough employee commuting)

- 7,656 miles (walking)- 15,504 miles (biking)- 62,952 miles (carpooling)-1,920 miles (transit)

= 4,739,808 total SOV miles/year from employee commuting

Converting Employee Commuting Miles to Tons CO2 Emissions

Annual employee commuting 4,739,808 miles

Annual gasoline use 234,644 gallons

Annual CO2 emitted 2,067 metric tons*

*Compare this to Chapel Hill’s 2008 fleet emissions of 1703 metric tons CO2 (Spring 2009 Capstone)

Proposals for Reducing Emissions from Employee Commuting

• Promote alternative transportation that reduces reliance on single-occupancy vehicles

• Sponsor initiatives to encourage carpooling

• Provide affordable housing in Chapel Hill to Town employees

Carpooling

• Put a price on parking

• Connect potential carpoolers

• Offer onsite amenities to reduce need for individual vehicles

• Provide emergency ride home service

Affordable Housing

• Many Town employees cannot afford to live in Chapel Hill

• Town purchase apartments and rent out to employees

Scope 3 Emissions from Solid Waste

Methodology: Solid Waste

Step 1: Waste audit of Town Facilities

Step 2: Apply estimated density of 89 pounds per cubic yard to TOCH waste

Step 3: Use Orange County Waste Stream Data to estimate mass totals for different constituents

Step 4: Input mass totals into the EPA Waste Reduction Model to determine total emissions

Methodology: Recycling

Step 1: Determine proportion of TOCH buildings serviced on recycling collection route

Step 2: Multiply this proportion by the total tonnage of recyclables collected on that service route for the 08/09 fiscal year

Step 3: Use Orange county information on recyclables to determine total mass of constituents (glass, plastic, etc.)

Step 4: Input these values into the EPA Waste Reduction Model to determine Saved Emissions

Annual Output by TOCH facility

Results: Solid Waste

Total Annual Emissions at current rates of disposal: 30 – 36 MTC02E

Material Tons Landfilled Total MTCO2E

Food Scraps 20.2 14

Mixed Paper 23.2 9

Newspaper 2.9 3

Mixed MSW 6.4 2

Mixed Plastics 17.2 1

Magazines/Third class mail 2.1 1

Mixed Metals 5.3 0-1

Glass 3.8 0-1

Dimensional Lumber .9 0-1

Clay Bricks .9 0-1

Tires 2.1 0-1

Yard Trimmings .3 0-1

Results: Recycling Total saved emissions from TOCH recycling: -84 MTCO2E

Material Tons Recycled Total MTCO2E

Mixed Paper 14.1 -50

Mixed Metals 2.7 -14

Corrugated Boxes 3.4 -10

Mixed Plastics 2.7 -4

Mixed Recyclables 1.3 -4

Glass 4.7 -1

Note: the high saved emissions from recycling results from the specifications of the WARM model, which analyzes life cycle emissions from new recyclable products.

Suggestions for Future Measurements

• Town implemented auditing program

– More efficient

Month Percent Full Volume to Mass

Waste Conversion

Factor

x 2 if

collected

twice weekly

x 4

(weeks

in a

month)

Monthly Solid

Waste

1

2

3

Pay-As-You-Throw

• Transparency: More efficient and accurate

• Economic Benefits– Dumpsters should only be picked up if half-

full

• Encourages Behavioral Changes– “Out of sight, out of mind”

– Increased yield in recycling

Composting Programs

•Preventable methane emissions•Landfill space•On-site composting programs

•Automatic•Manual

Material Tons Landfilled Total MTCO2e

Food Scraps 20.20 14

Mixed Paper (primarily from offices) 23.18 9

Newspaper 2.90 3

Mixed MSW 6.39 2

Mixed Plastics 17.21 1

Magazines/third-class mail 2.05 1

Glass 3.84 0

Dimensional Lumber 0.94 0

Yard Trimmings 0.34 0

Mixed Metals 5.28 0

Clay Bricks 0.85 0

Tires 2.05 0

Water and Wastewater

Greenhouse Gases Sources

• Two Sources of Emission

– Processing

– Human Waste

• Methane

• Nitrous Oxide

Processing

Electricity UseGHG Electricity Gas Use GHG Gas Annual GHG Total Annual VolumeGHG Emission Rate

(MWh) MTCDE (MMBtu) MTCDE MTCDE MG MTCDE/MG

Potable 8398 4367.135228 2441.5 129.5584417 4496.69367 3182.8 1.412810629

Wastewater 13738 7144.04665 11076.4 644.203424 7788.250074 2700.27 2.884248639

Emission Rate

Greenhouse Gas Produced (MTCDE)

Year 2005 2006 2007 2008

Water GHG 21 22 21 26

Wastewater GHG 18 19 19 18

Human

Nitrous Oxide

Methane

Year 2005 2006 2007 2008

Employees 680 701 704 699

kg of N2O Produced 4.8 4.9 4.9 4.9

MTCDE of N20 1.5 1.5 1.5 1.5

Year 2005 2006 2007 2008

GHG N/A N/A N/A N/A

Total

0

10

20

30

40

50

60

70

80

90

100

2005 2006 2007 2008

MTC

DE

Year

Greenhouse Gas Produced

Water GHG (MTCDE)

Wastewater GHG (MTCDE)

MTCDE of N20

Total GHG (MTCDE)

2008 Water Users

0

2

4

6

8

10

12M

illio

n G

allo

ns

User

2008 Water Usage

Water

Wastewater

Obstacles to Demand Reduction

• Water pricing is not a viable strategy

– Chapel Hill does not control its water or wastewater operations

• Voluntary demand reduction will not be effective either

– The majority of the town’s operations are in commercial and office settings: difficult for consumers to modify use

– Public housing is the largest water user: residents have no incentive to reduce water consumption

Solution: Retrofit buildings with more efficient appliances and fixtures

Daily Domestic Water Use:

Use Gallons per Capita Percentage of Total

Daily Use

Toilets 18.5 26.7%

Clothes Washers 15.0 21.7%

Showers 11.6 16.8%

Faucets 10.9 15.7%

Leaks 9.5 13.7%

Other Use 1.6 2.2%

Baths 1.2 1.7%

Dishwashers 1.0 1.4%

Low-flow Toilets in all Town Buildings

• Toilets installed prior to 1994 use anywhere from 3.5 to 7 gallons per flush

• Low-flow toilets use 1.6 gpf

• Assume the average person flushes the toilet 4 times a day while at work

– Savings of 1.6 gpf vs. 3.5 gpf = 7.6 gallons/day per employee

– Total annual savings of 1.3 million gallons for all 714 town employees (assumes 240 workdays per year)

Horizontal-axis Clothes Washers:Case study – Bern, Kansas

Additional Strategies

• Leak detection through regular system maintenance

• Retrofit other fixtures:

– Low-flow showerheads in public housing

– Low-flow faucet aerators in public housing and in all town buildings

• Reclaimed water for irrigation

• Community-wide reduction efforts

Transit Credit

Transit Credit

• Purpose: to calculate the emissions displaced by the Chapel Hill Transit system through:

– Mode shift

– Congestion relief

– Land use multiplier

Land-use multiplier

• Not included in total credit value, requires future analysis

• American Public Transportation Association (APTA) recommended methodology involves complex modeling procedures

• Methodology not suitable for transit providers in low-density suburban areas

Mode Shift

• Created ratio of transit passenger miles to displaced auto miles using Chapel Hill Transit Rider survey from Spring 2009 Capstone

• Determined number of miles that would have been driven without transit, converted to CO2 emissions

YearCO2 emissions offset (metric

tons)

2005 2996

2006 3080

2007 3094

2008 3098

Congestion Relief

• Calculated fuel saved per trip

• Used ridership values to determine gallons of excess fuel consumed, converted to CO2 emissions

Year CO2 emissions offset (metric tons)

2005 2585

2006 2230

2007 2318

2008 2671

Year

Total CO2 emissions

offset (metric tons)

Total CO2 emissions

produced (metric tons)

Total CO2 emissions

deficit (metric tons)

2005 5581 6095 (514)

2006 5310 6296 (986)

20075412 6687 (1275)

20085769 6818 (1049)

Total CO2 Emissions Offset of Chapel Hill Transit

•Displaces an average of 5518 metric tons CO2 per year

•Produces an average of 6474 metric tons CO2 per year

•Average net deficit of 956 metric tons CO2 per year

Conclusion

• Total Scope 3 Emissions (2008)

– Employee Commuting: 2067 MTCDE

– Solid Waste: 33 MTCDE

– Water 37 MTCDE

– Wastewater Treatment: 51 MTCDE

– N2O: 1.5 MTCDE

Transit Deficit: -1049 MTCDE

Conclusion

• Final Recommendations:

– Streamline data collection on scope 3 emissions

– Continue to explore opportunities for GHG reductions from commuters, solid waste, water, and wastewater treatment

Acknowledgements

Elizabeth ShayBrian RichardsonDaniel ArnemanEarl Bingham

Pat DavisJohn RichardsonMike Meagher

Rob TaylorAmanda Henley

Len ConeJohn Newark