Council Submits Comments to EPA on Implementing Sulfur Dioxide Standards

 June 29, 2012 - Today the Clean Air Council joined the Sierra Club and a coalition of citizen groups in submitting comments to EPA concerning a white paper for implementation of the 1-hour sulfur dioxide (SO2) national ambient air quality standards (NAAQS). 

The 1-hour SO2 NAAQS were finalized on June 2, 2010. Historically, states would show that they were meeting the NAAQS through air monitoring. However, due to the short-term standard a very large and expensive monitoring network would be required. The EPA indicated in its final SO2 rule that to avoid this expensive investment for a vast monitoring network, the Agency was considering relying more on air modeling. 

The EPA has received push back from states and industry on the feasibility of both modeling and monitoring. The coalition of citizen groups pushed in their comments for expeditious, comprehensive and accurate implementaion of the standard. Exposure to SO2, even in very short time periods, has significatn health impacts and causes decrements in lung function, aggravation of asthma and respiratory and cardiovascular morbidity. EPA must designate which regions of the county meet the standard within three years of finalization of the rule. These designations will affect the measures imposed upon these areas to meet the standard. 

Sierra Club has performed extensive modeling on the largest sources of SO2 pollution - coal-fired power plants. While EPA is not requiring modeling from the states when they submit their designation recommendations, the citizen groups are urging EPA to review their modeling, which shows drastic exceedences of the 1-hour SO2 standard. In making designations, EPA is required to base its decisons on all relevant data before it.

The citizen groups recommend that EPA should initially focus implementation on the 479 sources across the country that are responsible for 90% of SO2 ermissions, and use modeling to evaluate their SO2 NAAQS compliance. This number could be further reduced because some of the sources are retiring and some are in counties that are already modeling nonattainment and would be designated as such regardless.

The comments, which are attached below, condlude that EPA should rapidly implement the 1-hour SO2 NAAQS with a reliance on modeling - including third-party modeling - to make attainment/nonattainment designations by June 2013 as required by the Clean Air Act for 479 medium and large source of SO2.