Clean Air Council and Others Submit Comments on New EPA Sulfur Dioxide Guidance

On December 2, 2011, Clean Air Council along with Sierra Club and Earthjustice submitted comments to the U.S. Environmental Protection Agency (EPA) on their "Guidance for 1-Hour SO2 NAAQS SIP Submissions."

In the United States, 86.77% of sulfur dioxide (SO2) emissions in 2006 were produced from stationary source fuel combustion. About two-thirds of these SO2 emissions came from electric utilities. The major health effects from high exposure to SO2 include respiratory diseases, alterations in lungs' defenses and aggravation of existing respiratory and cardiovascular disease. It also damages trees and agricultural crops and is a major precursor to acid rain. Furthermore, it impairs visibility and corrodes buildings and monuments.

The Clean Air Act (CAA) requires EPA to set National Ambient Air Quality Standards (NAAQS) for six criteria pollutants, one of which is SO2. On June 2, 2010, EPA strengthened the primary SO2 NAAQS. The revised standard is intended to improve public health protection, especiallyu for people with asthma, children and the elderly. Once the NAAQS are set states must submit CAA section 110(a)(1) maintenance submittals, showing how they will meet and maintain the new levels. EPA indicated in the final rulemaking that the agency would provide additional guidance to the states about the process and requirements related to these maintenance submittals. 

The EPA offered the opportunity for public comment on the guidance on October 3, 2011 and then extended the comment period another 30 days.

Below you can find Clean Air Council's comments that general support the proposed guidance but call for several clarifications and shine a light on positions adopted in the guidance that are contrary to law:

• The Draft Guidance must be revised to make clear that (absent fully adequate monitoring at the point of maximum impact) only modeling—and not merely a demonstration of certain controls or compliance with other air quality rules—is sufficient to ascertain attainment;
• EPA must require states to complete modeling within six months, and must require redesignation to nonattainment of areas modeled to be in violation of the NAAQS;
• EPA must clarify that attainment designations and SIP approvals will be based on all available modeling data;
• The Draft Guidance must be revised to make clear that counties without large sources of SO2 should not automatically be assumed to be in attainment;
• Modeling based on emission limits with longer-than-hourly averaging times is likely to severely under-predict violations;
• The Draft Guidance needs greater clarity on the timetable for infrastructure SIPs to attain and maintain the 1-hour SO2 NAAQS;
• For nonattainment SIPs, EPA cannot ignore reasonable further progress;
• EPA should clarify the Draft Guidance’s statements concerning enforceable limits;
• The Draft Guidance must be revised to make clear that nonattainment designations take effect immediately upon promulgation; and,
• The Draft Guidance must be revised to clarify that SIP-adopted emissions limits provide for actual attainment.