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EPA Revises Greenhouse Gas Reporting Program Global Warming Potentials


On Nov. 29, 2013, EPA published a final rule to amend the Greenhouse Gas (GHG) Reporting Program 40 CFR Part 98. The rule became effective on Jan. 1, 2014. The final rule revises the global warming potential (GWP) of some GHGs, provides technical corrections and clarifying provisions and establishes confidentiality for new or revised data elements. Existing reporters are required to use the updated GWPs for reporting year 2013 which must be submitted to EPA by March 31, 2014.

The GWP of certain GHGs has been revised to reflect the GWPs published in the Intergovernmental Panel on Climate Change Fourth Assessment Report. EPA stated the changes were being made to improve the quality of reported emissions and to ensure the comparability of data collected in the GHG Reporting Program to the inventory EPA compiles annually to meet international commitments and to GHG inventories prepared by other countries. The revisions affect certain GHGs including methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), certain hydrofluorocarbons (HFCs), certain perfluorocarbons (PFCs) and certain other fluorinated greenhouse gases (F-GHGs). For the most part, the revisions result in increases to the GWP of the affected GHGs; however, there are some decreases. For example, the GWP for methane was increased from 21 to 25, while the GWP for N2O was decreased from 310 to 298.

Increasing the GWP will result in increased levels of GHGs reported and is also expected to result in an increase in the number of facilities that will be subject to reporting requirements. EPA stated that the majority of additional reporters would be from the petroleum and natural gas sector as well as municipal and solid waste landfills. EPA has estimated that the GWP revisions will increase the number of facilities required to report under the program “by about 180.” First time reporters brought into the GHG Reporting Program because of the GWP changes were required to begin data collection on Jan. 1, 2014, and will be required to submit their first reports by March 31, 2015. The rule provides these first time reporters with the opportunity to use best available monitoring methods, for specified time periods, for any parameter that cannot reasonably be measured according to the monitoring and quality assurance/quality control provisions of the rule. 

Impacts from the GWP revisions are not limited to reporting. The revisions can have Prevention of Significant Deterioration (PSD) and Title V permitting implications as well. Pursuant to the GHG Tailoring Rule, PSD and Title V permitting applicability is based in part on CO2e emissions which are calculated using the GWP values being revised. Thus, a facility assessing PSD or Title V applicability would utilize the revised GWP values finalized in this rule in determining its CO2e emissions which could result in more stringent permit requirements.

Confidentiality determinations are established in the rule for the reporting of new or substantially revised data elements contained in these final amendments. The final rule also includes clarifications to terms and definitions for certain emission equations, simplifications to calculation methods and data reporting requirements and corrections for estimated emissions in total source category emissions.

To view a complete PDF of the Fourth Quarter 2013 issue of the Air Quality Letter, click HERE.

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