Organic Waste Composting FAQs

  1. What are the different types of composting systems, and which are likely to meet the Best Management Practices (BMP) requirements of the OWC protocol?
  2. According to the OWC protocol, a project is defined as the diversion of one or more eligible waste streams to an aerobic composting facility. What defines a facility?
  3. What are the eligible waste streams for an OWC project?
  4. What are the eligibility requirements regarding food waste from supermarkets or grocery stores?
  5. Why are FOG (fats, oils, and greases) wastes excluded from eligibility?
  6. How long is the crediting period of an OWC project?
  7. What if the CRTs (offsets) generated by a project are owned by two parties? Which one should be the account holder in the system?
  8. What happens if my project was issued a Notice of Violation (NOV) by a regulatory body or there was an event in which the project was out of regulatory compliance?
  9. What are the site-specific waste sampling requirements for SSO Waste Streams? Are the requirements the same for residential and commercial waste streams?

  1. Q: What are the different types of composting systems, and which are likely to meet the Best Management Practices (BMP) requirements of the OWC protocol?
    A: A Turned Windrow system is the predominant method of composting in the U.S. It involves making elongated piles, which are turned with a tractor, front-end loader, or other specialized turning equipment. Some facilities can make quality compost in 8 to 9 weeks or longer, and temperatures reach the point of pathogen destruction. Any anaerobic regions are concentrated at the bottom of the windrow. Additional water is added to maintain moisture for microbial decomposition. This system is likely to meet the BMP requirement.

    Aerated Static Pile systems use a blower to introduce air into the composting mass, either with positive or negative pressure. The systems may or may not be contained using a membrane cover, an enclosed vessel, or in-building system. The advantage of negatively aerating a static pile is that the exhaust can be directed to a point source and put through a control system such as a biofilter. Although this is a less common system, it is likely to meet the BMP requirements of the protocol.

    Passive Pile systems rely predominantly on natural convection, and are often turned very infrequently. They are likely to contain anaerobic pockets, and temperatures in these piles may not heat up to regulatory requirements for pathogen destruction. For these reasons, passive piles do not meet the BMP requirements of the protocol.

  2. Q: According to the OWC protocol, a project is defined as the diversion of one or more eligible waste streams to an aerobic composting facility. What defines a facility?
    A: First, the intent of the project definition is to require that each project is tied to one (and only one) facility. Second, a facility must be involved in the aerobic processing of biodegradable organic solid waste components to produce a mature product for beneficial use. A composting facility typically includes waste collection, storage, and mixing areas, active composting areas, compost curing areas, and storm water drainage systems. A composting facility can be stand-alone or may be incorporated into an existing landfill facility, Material Recovery Facility (MRF) or other waste handling facility. Multiple aerobic composting technologies may be utilized at one facility.

  3. Q: What are the eligible waste streams for an OWC project?
    A: 1) Municipal solid waste (MSW) food waste such as uneaten food, food scraps, spoiled food, and food preparation wastes from homes, restaurants, kitchens, grocery stores, campuses, cafeterias, or similar institutions.
    2) Non-recyclable food-soiled paper waste co-mingled with eligible food waste, such as napkins, tissues, paper plates, paper cups, fast food wrappers, used pizza boxes, wax-coated cardboard, and other similar paper or compostable packaging items.

  4. Q: What are the eligibility requirements regarding food waste from supermarkets or grocery stores?
    A: MSW food waste and food-soiled paper waste streams are not eligible if sourced from grocery stores and/or supermarkets that have historically diverted these waste streams from landfills. Waste streams originating from new grocery store facilities are deemed eligible.

    Also, the project must demonstrate the eligibility of each new grocery store waste stream composted by the project by documenting that the food and food-soiled paper component of the grocery store waste was being disposed of in a landfill for a period of at least 36 months prior to the date that the grocery store waste was first delivered to the project composting facility, or documenting that the grocery store waste stream was previously deemed to be an eligible waste stream at another OWC or OWD project that is registered with the Reserve.

  5. Q: Why are FOG (fats, oils, and greases) wastes excluded from eligibility?
    A: An analysis was conducted by Science Applications International Corporation (SAIC) in January to May of 2009, which established a performance standard evaluating organic waste management practices. SAIC found that it was common practice that FOG waste is recognized as a recyclable resource and only small quantities are being sent to landfill. Therefore, these waste types would not typically qualify as achieving significantly improved GHG performance through diversion to composting projects. Please refer to Appendix B of the protocol for further information.

  6. Q: How long is the crediting period of an OWC project?
    A: 10 years. After the first 10-year crediting period, projects may apply for a second 10-year crediting period, but they must meet the eligibility requirements of the most current version of this protocol, including any updates to the performance standard test, as of the time that the second crediting period is requested.

  7. Q: What if the CRTs (offsets) generated by a project are owned by two parties? Which one should be the account holder in the system?
    A: All the Climate Reserve Tonnes (CRTs) generated by a project must be unambiguously owned by one party, and that organization must be the account holder in the Reserve software. If multiple parties are involved, and they wish to share project revenue or receive/transfer CRTs after a project is registered, this must be clearly documented in contracts and agreed to by the different parties. Ultimately, one party must be given sole ownership over the initial issuance of CRTs. During verification, verification bodies will need to confirm the exact ownership regime, especially in instances where multiple parties are involved in the development of the project. CRTs shall never be double counted or owned by multiple parties at the same time.

  8. Q: What happens if my project was issued a Notice of Violation (NOV) by a regulatory body or there was an event in which the project was out of regulatory compliance?
    A: Project developers are required to submit a signed Attestation of Regulatory Compliance at the end of each reporting period. For any period of time in which the project was out of material compliance with any laws (e.g. environmental, safety, etc.), the project may not claim any emission reductions. Instances of non-compliance only affect crediting if they are either recurrent or the result of negligence or intent. In addition, only violations related to the project activity (e.g. digester, flares, engine, effluent storage, etc.) affect project crediting. Project developers must submit in writing a list of all NOVs (project and non-project related, material and immaterial, etc.) during the reporting period to their verifier. Ultimately, the decision about what is material and what may affect project crediting is subject to verifier professional judgment, based on the guidelines in the OWD protocol and the Reserve’s Verification Program Manual.

  9. Q: What are the site-specific waste sampling requirements for SSO Waste Streams? Are the requirements the same for residential and commercial waste streams?
    A: Residential Source Separated Organics (SSO) waste streams may use local municipal waste characterization data provided by the local jurisdiction or a representative entity to quantify the proportion by weight of both food waste and soiled paper in the waste stream. The second option is to follow the site-specific waste sampling requirements below:

    • All hand-sorting events shall use at least a 100 lb sample from a recent delivery of the residential SSO stream in question prior to mixing with other waste streams
    • The SSO waste sample shall be sorted into the following categories: food waste, soiled paper, other ineligible material
    • Each sampling event must quantify and record the proportional weight of food waste and of soiled paper as compared to the total weight of the sample
    • Each residential SSO stream shall have a minimum of 8 sampling events (2 per quarter) for the first year that the stream is composted at the facility, followed by 4 sampling events every year thereafter for each SSO stream (1 per quarter)
    • The project must quantify the mean food waste proportional weight and soiled paper proportional weight, FFW,S and FSP,S, respectively, for each quarter of the calendar year
    • Photo documentation must be recorded and retained for verification purposes, clearly showing the waste stream from which the sample is taken, the waste sample itself, and the separated categories of waste following the hand sorting

    Commercial SSO waste streams are likely to contain a high proportion of soiled paper waste compared to food waste; however, on a weight basis it would be expected that the fraction of food waste is higher due to the fact that food waste is very high in moisture, whereas paper material would be much less dense with a lower moisture content. Table 5.1 in the OWC protocol shows the default food and soiled paper fractions by weight for different waste generator categories. Projects with commercial SSO waste streams may apply the default values listed in Table 5.1, or may use the site-specific waste sampling as described for residential SSO waste streams above.