The New Rule is less stringent, but gives the agencies more flexibility
On August 21, 2015 the U.S. Environmental Protection Agency (EPA) published the final Sulfur Dioxide (SO2) Data Requirements Rule (DRR). It requires that state and tribal air agencies (air agencies) provide data to EPA that will be used to characterize one hour average SO2 concentrations near large sources of emissions. These data will be used to demonstrate compliance with the 1-hour average National Ambient Air Quality Standard (NAAQS). The final rule differs from the proposed rule in several ways. The final DRR:
The map below shows over 400 sources that exceed the 2000 t/y threshold and may be subject to the final rule. However, air agencies and EPA may include other sources and areas that in their opinion warrant characterization. Air agencies are required to develop and submit a list of sources exceeding the threshold, based on the most recent year of available SO2 emissions data, and indicate the areas that will be characterized.
The final rule establishes the following timeline and milestones for implementation:
What should sources do now?
SO2 emissions from targeted DRR sources may be affected by other recently finalized EPA rules, e.g., Mercury and Air Toxics Standards (MATS) and Clean Power Plan, or proposed rules. The impact of these rules on future SO2 emissions to specific sources should be considered to determine the feasibility of reducing emissions to below 2000 t/y and avoid being subject to the DRR. In addition to examining solutions through emission reductions, a modeling analysis should be undertaken to determine if compliance with the NAAQS can be demonstrated with current or reduced emissions. These analyses and results will be helpful in discussions with the air agency in selecting the most appropriate compliance strategy for your facility.
Contact us for assistance
TRC’s staff of permitting engineers, modelers and ambient monitoring experts can identify and evaluate the most appropriate option for your plant and emission sources. It is not too early to determine the best strategy for your sources.