Carbon Offsets from Organic Waste Conversion Projects

New protocols from the Climate Action Reserve provide incentives to divert food wastes from landfills. These include an existing digestion protocol and a forthcoming composting protocol.

Max DuBuisson and Syd Partridge

The Climate Action Reserve (the Reserve) has long had a protocol to give credit for the capture and destruction of methane emissions from organic waste in landfills, but they have now opened up the possibility of credits for projects that prevent that waste from entering landfills in the first place. In October 2009, the Reserve adopted the Organic Waste Digestion Project Protocol, covering both municipal food waste and agro-industrial wastewater. In December, they kicked-off development of the Composting Project Protocol, due to be completed and adopted in June of 2010. Many municipalities have become interested in diverting organic waste from landfills to other technologies for waste conversion, but these can be expensive enterprises. Carbon offsets can provide an important revenue stream to help finance these projects.

Organic Waste Digestion (OWD)

Anaerobic digestion is not a new technology, but it has been enjoying a renaissance as more people are realizing the benefits, and advances have been made in digester design and operation. The OWD protocol outlines eligible waste streams, including MSW (municipal solid waste) food waste and agro-industrial wastewater, and also provides requirements for monitoring, metering and verification.

Post-consumer food waste makes up about 12.5 percent of all MSW nationwide, and only about 2.6 percent of this is currently diverted from landfill. In the landfill, organic waste decays over time and releases methane as landfill gas (LFG). Methane is a potent greenhouse gas—21 times more potent than carbon dioxide in our atmosphere. It can also pose a threat to local groundwater by migrating out of the landfill. When MSW food waste is diverted to an anaerobic digester, the project generates credits based on the avoided emissions from landfills.

The OWD protocol takes a standardized approach, assuming that the food waste would have been sent to a landfill, and that all landfills have gas collection systems that reach the waste after it has been in the landfill for three years. A first order decay (FOD) model is used to calculate how much methane would have been generated by the specific amount of food waste over time. Since the crediting period for landfill projects is 10 years, each calculation is for 10 years’ worth of decay in the landfill, minus what would have been destroyed in the LFG collection system. The protocol credits digestion of non-industrial food waste such as uneaten food, food scraps, spoiled food and food preparation wastes from homes, restaurants, kitchens, grocery stores, campuses, cafeterias and similar institutions. Industrial food waste such as solids from food processing facilities generally still has a use value and is not typically disposed of in a MSW system.

Agro-industrial wastewater streams are generally eligible if they originate from a privately-owned treatment facility, and have a baseline management system that uses uncontrolled anaerobic treatment (usually a lagoon or open tank at least one meter in depth). The waste streams are then diverted to a closed, anaerobic digester to allow for collection and destruction of the methane gas. Credits are based on the characteristics of the particular waste stream, using periodic sampling of chemical oxygen demand (COD) to model the avoided baseline emissions. Excluded sources include municipal wastewater, pulp and paper mills, breweries, ethanol plants and pharmaceutical production facilities.

The OWD protocol also allows for co-digestion projects, which can include any combination of eligible and ineligible waste streams, as well as livestock manure. Credit is only given for eligible waste streams. If livestock manure is being digested, project developers will refer to the Livestock Project Protocol for guidance on quantification of that waste stream.

Destruction of the gas may occur onsite (flare, engine, fuel cell, turbine) or offsite (pipeline, vehicle fuel). Credits are not given for avoided emissions due to the generation of renewable electricity, but renewable energy credits may be sought from another program, since these represent a different set of emissions being avoided.

The crediting period for OWD projects is 10 years from the project’s start date, and is renewable one time if the project meets the eligibility requirements of the version of the protocol that is current at that time. A project’s start date is defined by the day that the project begins generating and destroying methane produced from the digestion of eligible waste. Project developers have a six-month window from that day to optimize their system before they must declare a start date. Projects must be submitted to the Reserve for Listing within six months of the declared start date. There is a grace period, however, whereby projects with start dates as early as October 7, 2007 may still be submitted to the Reserve until October 7, 2010.


The kick-off meeting for the Composting Project Protocol was held in Portland, OR in December 2009. This protocol has the same goal as that of the OWD protocol: to divert MSW food waste from landfills, thereby avoiding methane emissions in landfill gas. The credit quantification will be very similar to the MSW food waste calculations in the OWD protocol.

At the moment, the Reserve has formed the stakeholder workgroup based on applications that were submitted after the kick-off meeting. The Policy team will now work with this group to develop a draft of the protocol. After the workgroup has reviewed and commented on the first draft, the Reserve will develop a revised draft that will then be made available for public comment from the Reserve website (, this will occur between mid-April and mid-May). All interested stakeholders are invited to submit any useful comments that you may have regarding this draft. During the public review process, the Reserve will host a workshop to encourage further public feedback. Once the public comment period has closed, the Reserve will review, respond, and incorporate the public’s feedback. A final draft will then be presented to the Reserve Board of Directors for adoption at their meeting in June.

Both of these protocols offer a new source of revenues to help finance waste conversion projects. The U.S. carbon market is growing quickly. There is demand not only for the carbon credits from digestion and composting projects, but also for the renewable energy that they may be able to generate.

Max DuBuisson is the Business Development Associatefor the Climate Action Reserve (Los Angeles, CA). Max works on the growth and development of the Reserve through public outreach. He serves as a source for inquiries and information for interested stakeholders, especially concerning methane destruction projects. Max has been with the Reserve since 2008. He can be reached at (213) 785-1233 or via e-mail at [email protected].

Syd Partridge is a Policy Manager at the Climate Action Reserve (Los Angeles, CA). He works on the development of offset project protocols, including the OWD, Composting, and Livestock protocols, leading them through all steps of the protocol development process. He also developed the Livestock Beta Calculation Tool. Syd has been with the Reserve since 2007, and can be reached at (213) 542-0294 or via e-mail at [email protected].

The Climate Action Reserve (Los Angeles, CA) is a national offsets program working to ensure integrity, transparency and financial value in the U.S. carbon market. It does this by establishing regulatory-quality standards for the development, quantification and verification of greenhouse gas (GHG) emissions reduction projects in North America; issuing carbon offset credits known as Climate Reserve Tonnes (CRT) generated from such projects; and tracking the transaction of credits over time in a transparent, publicly-accessible system. Adherence to the Reserve’s high standards ensures that emissions reductions associated with projects are real, permanent and additional, thereby instilling confidence in the environmental benefit, credibility and efficiency of the U.S. carbon market. For more information on the Organic Waste Digestion Project Protocol, visit For more information on the Composting Project Protocol, visit