EPA releases framework for assessing biogenic CO2 emissions from stationary sources

On November 19, the Environmental Protection Agency (EPA) released a document titled Framework for Assessing Biogenic CO2 Emissions from Stationary Sources. The framework, technical appendices, and related documents may be accessed at http://www.epa.gov/climatechange/ghgemissions/biogenic-emissions.html. The framework is a revision of EPA's original September 2011 Draft Accounting Framework which underwent peer review by the Biogenic Carbon Emissions Panel of EPA’s Science Advisory Board. A memorandum by Janet G. McCabe, Acting Assistant Administrator, Office of Air and Radiation, indicates that the EPA “anticipates near-term decision-making pertaining to biogenic CO2 emissions in the context of both the Clean Power Plan (CPP) and the Prevention of Significant Deterioration (PSD) program. As a result, we expect that many states and stakeholders will look to the second draft of the Framework for indications of how the Agency will treat biogenic CO2 emissions under both the CPP and the PSD program going forward.”

The McCabe memo contains important clarification on how EPA intends to address biogenic feedstocks and biogenic CO2 under the CPP and PSD program. In specific, the memo states that “information considered in preparing the second draft of the Framework,...supports the finding that use of waste-derived feedstocks and certain forest-derived industrial byproducts are likely to have minimal or no net atmospheric contributions of biogenic CO2 emissions, or even reduce such impacts, when compared with an alternate fate of disposal. The EPA intends to apply this preliminary finding further within the [CPP and PSD program].” The memo also indicates that other feedstocks that are sustainably produced will qualify under the CPP program and that biogenic CO2 from wastes and sustainably produced feedstocks will be exempted from BACT analysis under the PSD program. The criteria to be used in defining “sustainably produced biomass,” however, are not specified. The memo indicates that these criteria will be the subject of ongoing analysis and consultation that will include the examination of “existing state and third-party programs”.

The 69-page framework document includes chapters titled “Biogenic Assessment Factor Equation,” “Representative and Customized Approaches to Landscape and Process Attributes,” and “Technical Considerations.” The framework also references 14 technical appendices that
address temporal scale, spatial scale, anticipated baselines, feedstock categories, and other issues. The methodology in the report includes technical elements that can be adapted to reflect a variety of policy scenarios based on key decisions by the user, including type of baseline (e.g., reference point or anticipated), time frame of the assessment (e.g., future or historical, 20, 30, 50, 100 years), feedstock categories (i.e., waste-, agriculture-, and forest-derived), and scale (e.g., state, regional, national). The document also discusses publicly available data sets that could be used in the framework.

Because the first draft of the framework has been significantly updated and revised, EPA has requested that the Science Advisory Board consider reconvening members of the original Biogenic Carbon Emissions Panel to conduct a targeted peer review of specific elements in the revised framework. NCASI also will be reviewing technical aspects of the framework.