Skip to Main Content
(Press Enter)

/ Environmental /
Carbon Footprint Calculation Methodology

Waste Management’s carbon footprint comprises the anthropogenic Scope 1 (direct) and Scope 2 (indirect) greenhouse gas (GHG) emissions from facilities and activities under Waste Management’s operational control in North America as well as Scope 3 (indirect) GHG emissions.

Scope 1 emissions include direct emissions from landfills, fleet vehicles, support vehicles, heating and refrigerants. Scope 2 emissions include indirect emissions from purchased electricity. Scope 3 emissions include purchased goods and services, capital goods, business travel, employee commuting, upstream and downstream leased assets, and investments. Our carbon footprint calculation relies on company operating data collected from auditable corporate business, legal and accounting records, which have undergone internal quality assurance. Emissions factors and methodologies come from the following sources:

  • U.S. Environmental Protection Agency (EPA), Mandatory Greenhouse Gas Reporting Rule (MRR), 40 CFR Part 98
  • EPA, Emission Factors for Greenhouse Gas Inventories; Updated March 9, 2018
  • EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks
  • EPA, eGRID Technical Support document, Chapter 3
  • The Climate Registry, 2018 Default Emissions Factor Document; Updated May 2018
  • Environment and Climate Change Canada, National Inventory Report 1990-2017: Greenhouse Gas Sources and Sinks in Canada (Part 3, Annex 13)
  • U.S. Department of Energy (DOE), 1605(b) Voluntary Reporting of Greenhouse Gases Program, Technical Guidelines
  • DOE Energy Information Agency (EIA), Emissions of Greenhouse Gases in the United States, documentation and Emission Factors
  • International Panel on Climate Change (IPCC), 2006 Guidelines for National Greenhouse Gas Inventories
  • IPCC, Climate Change 2013: The Physical Science Basis. Fifth Assessment Report
  • IPCC, Climate Change 2007: The Physical Science Basis. Fourth Assessment Report
  • Solid Waste Industry for Climate Solutions (SWICS) Protocol by SCS Engineers, version 2.2
  • EPA, Climate Leaders Program, Technical Guidance
  • World Resources Institute and World Business Council on Sustainable Development, The Greenhouse Gas Protocol
  • World Resources Institute and World Business Council on Sustainable Development, The Greenhouse Gas Protocol Scope 2 Guidance
  • U.S. Community Protocol for Accounting and Reporting of Greenhouse Gas Emissions, Method WW.14.
  • EPA, 2020 SmartWay Truck Carrier Partner Tool: Truck Tool Technical Documentation, U.S. Version 2.0.19 (Data Year 2019)
  • Gasoline: Final Rule on Light-Duty Vehicle Greenhouse Gas Emissions Standards and Corporate Average Fuel Economy Standards (75 FR 25324, May 7, 2010). The gasoline factor used in this rule was sourced from the California Air Resources Board and is based on measurement of carbon from a gasoline test fuel (indolene).
  • Diesel: Fuel economy calculations in 40 C.F.R 600.113
  • Compressed Natural Gas (CNG): Calculations of Lifecycle Greenhouse Gas Emissions for the 2005 Gasoline and Diesel Baselines in the Notice of Availability of Expert Peer Review Record supporting the proposed revisions to the Renewable Fuel Standard Program (74 FR 41359) available in Docket EPA-HQ-OAR-2005-0161-0925.1 (Spreadsheet “Emission Factors”).
  • Liquefied Natural Gas (LNG): Calculations of Lifecycle Greenhouse Gas Emissions for the 2005 Gasoline and Diesel Baselines in the Notice of Availability of Expert Peer Review Record supporting the proposed revisions to the Renewable Fuel Standard Program (74 FR 41359) available in Docket EPA-HQ-OAR-2005-0161-0925.1 (Spreadsheet “Emission Factors”).
  • Carbon Footprint: Country Specific Electricity Grid Greenhouse Gas Emission Factors. 2019 Grid Electricity Emissions Factors v1.0 — June 2019.

Because a broadly accepted protocol for estimating the carbon mass balance of landfills does not yet exist, Waste Management, along with other public and private owners and operators of landfills, funded the development of the Solid Waste Industry for Climate Solutions (SWICS) protocol by SCS Engineers. The protocol represents a first step in refining existing U.S. EPA models and protocols using peer-reviewed, published research to improve landfill GHG emission estimation. We employed the SWICS protocol in estimating the emissions associated with the landfill operations reported in our company-wide carbon footprint and the voluntary GHG reporting protocols in which we participate. The U.S. EPA’s Science Advisory Board views some sources of biogenic carbon dioxide emissions — including landfill gas and biogenic materials in waste — as carbon neutral, so these are not included in our footprint.

Carbon storage in landfills can significantly offset GHG emissions from landfills, as recognized by the United Nations Intergovernmental Panel on Climate Change, the EPA’s U.S. Inventory of GHG Emissions and Sinks, the Oregon Climate Trust and the California Air Resources Board — all of which recognize carbon storage in landfilled material as a “sink” in calculating carbon emissions inventories. We have used the SWICS protocol to calculate the amount of carbon permanently stored in landfills from the annual disposal of organic waste — i.e., carbon that will not decompose in the landfill to produce methane.

Beginning in 2013, we aligned our emissions reporting with that of U.S. EPA, which continues to refine its default assumptions and scope of reporting under its mandatory reporting program. For sites exempt from U.S. EPA’s rule (too old, too small, non-MSW landfill), we calculate a default representing the proportion of emissions thereby omitted and increase the reported emissions included in our footprint to allow our emissions to be compared year over year. As part of this process of aligning our reporting with SWICS and the U.S. EPA, beginning with our 2013 emissions reporting, we are using the modified 100-year global warming potentials (GWPs) promulgated by EPA in its November 29, 2013, revisions to 40 CFR Part 98 (78 Fed. Reg. 71904). Pertinent to Waste Management’s carbon footprint, the EPA revised the GWP for methane from 21 to 25 and the GWP for nitrous oxide from 310 to 298.

Additionally, Waste Management has developed a GHG Inventory Management Plan (IMP) for internal use. The IMP is a dynamic document to provide Waste Management with a summary of emission sources associated with the company’s activities, and the associated emissions quantified using standardized methods. Included in the inventory are processes for:

  • Choosing a base year for the GHG emissions inventory against which future emissions will be tracked.
  • Identifying the sites to include in the inventory (“organizational boundaries”).
  • Identifying the sources within the sites to include in the inventory (“operational boundaries”).
  • Following a standardized and accepted methodology to calculate the GHG emissions from each identified source.

Our GHG inventory reflects the most accurate means available to calculate GHG emissions within our industry sector. We work with leaders in government, industry and academia, including staff of the multistate Climate Registry and the U.S. EPA, to develop our inventory processes and protocols.

Data Verification and Validation

We participate in multiple forms of data verification. First, in conformance with applicable state or provincial GHG emissions-reporting programs, an independent third party is hired to review original data and provide a verification certificate. Accordingly, the emissions from the landfill subject to the Alberta Provincial Specified Gas Emitters Regulatory Reporting Program were third-party verified by GHD for 2018; 2019 is in progress and we anticipate a successful verification. Emissions from the landfill subject to State of California mandatory reporting program were third-party verified by Analytical Environmental Service (AES) for 2018; 2019 is in progress and we anticipate a successful verification. All our facilities are subject to the federal Mandatory GHG Reporting Rule for 2018 and 2019, which includes nearly 240 landfills that are subject to rigorous validation checks by U.S. EPA as part of its compliance assurance and enforcement program for the reporting rule.

In 2019 and 2020, Waste Management hired Aster Global (AG) to conduct a third-party verification of the company’s 2018 and 2019 carbon footprint, respectively. Both verifications were conducted in accordance with ISO 14064–3:2006 specification with guidance for validation and verification of GHG assertions to provide limited assurance that the Scope 1, Scope 2 and Scope 3 GHG data was prepared in conformance with World Resource Institute/World Business Council for Sustainable Development GHG Protocol: A Corporate Accounting and Reporting Standard and the internal Waste Management Inventory Management Plan. As a result, 100 percent of our carbon footprint is verified by a third party.

In a second form of data validation, we report to a third party, such as a government-affiliated data tracking program, which provides QA/QC to the data but does not provide a verification certificate. Our transportation data is validated through the U.S. EPA SmartWay program; our GHG inventory from energy generation is validated by U.S. EPA; and our GHG inventory from California, reported to the California Air Resources Board, is verified by SCS.

Further, Waste Management has contracted with Enel X to collect and pay utility invoices, as well as to track usage data as part of an enterprise-wide utility bill management (UBM) program spearheaded by our supply chain procurement managers. Information from the UBM program is audited prior to bill redirection by Waste Management to ensure correct processing of all future invoices. We review data through Enel’s online dashboard and have the capability to run reports on consumption, cost and GHG emissions on a facility, region, division, country and enterprise-wide basis. With this approach, our data collection and reporting program is robust and transparent.

Life Cycle Emissions Methodology

Our calculation of the potential GHG reductions or avoided emissions that our operations enable includes the following:

Electricity. Production of renewable waste-based energy that is used to replace electricity generated from fossil fuels.

Fuel. The use of renewable natural gas (RNG) to avoid the GHG emissions associated with annual use of fossil fuel.

Recycling. Recycling of postconsumer materials (e.g., paper, aluminum and plastics) using U.S. EPA’s Waste Reduction Model (WARM).

Carbon sequestration. Permanent carbon storage in landfills of biogenic materials that do not decompose in an anaerobic landfill environment.

2014 was the first time we prepared a benchmarking of companies, projecting a cost of carbon for review by the Board of Directors. We continue to update the Board on changes in Waste Management’s footprint, with the ongoing obligation to update the Board in the event of a major change in customers’ disclosed carbon pricing strategies. We review how carbon pricing models or cap-and-trade programs are applied in North America. We have concluded that because of the complex nature of our business and high variability in state approaches, with carbon emissions offset by carbon-reducing services like recycling, renewable energy production and carbon sequestration in landfills, the absence of a clear regulatory framework for carbon pricing for our sector makes price projections unreliable. Our assessment has been further complicated by recent U.S. position changes on climate strategy, and we continue to monitor state government and customer response strategies closely. Anticipating a price on carbon is part of our initiative to change reporting on recycling productivity from tonnage to GHG reductions gained. We believe our ability to provide verifiable metrics on carbon reduction to our customers will be a competitive advantage.

Electricity Consumption Data by Business Division

Through the UBM system, Waste Management can pull data by business division.

Market Area Electricity (kWh)
WM of Arkansas Tennessee Alabama Kentucky 17,550,001
WM of Eastern Canada 27,878,524
WM of Florida 38,845,006
WM of Four Corners 26,473,566
WM of Greater Mid Atlantic 62,995,261
WM of Gulf Coast 31,290,817
WM of Illinois Missouri Valley 39,686,321
WM of Michigan Ohio Indiana 44,142,032
WM of New England 25,616,497
WM of Northern California 17,497,829
WM of Pacific Northwest BC 31,010,247
WM of South Atlantic 17,596,752
WM of Southern California 32,152,855
WM of Texas Oklahoma 35,126,374
WM of Western Canada 4,902,589
WM of Western Pennsylvania Maryland West Virginia Virginia 57,191,345
WM of Wisconsin Minnesota 31,971,916
Closed Sites 9,560,210
Corporate* 11,172,133
Energy and Environmental Services 850,233
WM Renewable Energy 37,563,346
WM SBS 1,398,362
WM Tracker 1,210,147
Total 603,682,363

*Corporate includes enterprise-wide support locations including Corporate Offices, Call Centers, Data Centers, Training Centers, and WM Aviation.

Energy Consumption (MWH)
2016 2017 2018 2019
Non-Renewable Fuels 2016: 6,852,697 2017: 6,852,233 2018: 7,033,506 2019: 6,651,407
Non-Renewable Electricity 2016: 500,353 2017: 530,903 2018: 583,680 2019: 602,321
Total Non-Renewable Energy 2016: 7,353,050 2017: 7,383,136 2018: 7,617,186 2019: 7,253,728
Renewable Fuels 2016: 177,504 2017: 283,136 2018: 467,327 2019: 1,208,877
Renewable Electricity 2016: 0 2017: 0 2018: 122 2019: 1,362
Total Renewable Energy 2016: 177,504 2017: 283,136 2018: 467,449 2019: 1,210,238
Total Energy 2016: 7,530,553 2017: 7,666,272 2018: 8,084,635 2019: 8,463,966
Percent Renewable Energy 2016: 2.36% 2017: 3.69% 2018: 5.78% 2019: 14.30%