* — * U.S. Environmental Protection Agency 18-P-0129 March 16, 2018 . u.o. tiiviiuiiiiitriiidi riuicuu \ Office of Inspector General At a Glance Why We Did This Review The U.S. Environmental Protection Agency's (EPA's) Office of the Inspector General conducted this review in response to a hotline complaint alleging that the EPA used results from two flawed studies to estimate methane emissions and make policy decisions regarding oil and natural gas production. The complaint alleged that two methane emissions studies conducted by the University of Texas-Austin (UT-Austin), and sponsored by the Environmental Defense Fund (EDF), were flawed due to a malfunction in one of the measurement devices called a Hi Flow Sampler. Our objectives were to determine (1) how the EPA estimates methane emissions from oil and natural gas production, including whether the EPA used results from the two EDF/UT-Austin studies to estimate emissions; and (2) whether concerns about technical or other problems with the studies were identified or brought to the EPA's attention, and how the EPA addressed and resolved those concerns. EPA Did Not Use Allegedly Flawed Studies to Estimate Methane Emissions or Set New Source Performance Standards for Oil and Natural Gas Production Methane is a potent greenhouse gas emitted from natural and industrial sources, including oil and natural gas production facilities. What We Found The Inventory of U.S. Greenhouse Gas Emissions and Sinks (Greenhouse Gas Inventory) reflects the EPA's official nationwide estimate for greenhouse gas emissions from all man-made sources, including those from oil and natural gas production. The inventory is developed using a variety of data sources and emission estimation methodogies. One source of data for the inventory is emissions and activity data reported to the EPA under its Greenhouse Gas Reporting Program. This reporting program requires large emission sources and fuel suppliers to calculate and report their greenhouse gas emissions data to the EPA. The EPA used its Greenhouse Gas Inventory development process to consider information related to the EDF/UT-Austin studies and the Hi Flow Sampler. In memorandums issued in 2015 and 2016, inventory staff requested expert and public feedback on specific aspects of the EDF/UT-Austin studies, how data could potentially be used for the inventory, and potential problems with the Hi Flow Sampler. The EPA ultimately did not make any methodological revisions to the Greenhouse Gas Inventory or to the Greenhouse Gas Reporting Program based on the EDF/UT-Austin studies, and data from the studies have not been incorporated into the inventory. In addition, the EPA did not use any data from the EDF/UT-Austin studies to set the final 2016 New Source Performance Standards to limit methane emissions from the oil and natural gas industry. We make no recommendations. This report addresses the following: • Improving air quality. Send all inquiries to our public affairs office at (202) 566-2391 or visit www.epa.gov/oiq. Listing of OIG reports. ------- |