The Clean Air Act requires the EPA to review the ozone pollution standards every five years. The current standard, which was set in 2008, is 75 parts per billion (ppb). Last November, the agency proposed to strengthen air quality standards to within a range of 65 to 70 parts per billion (ppb), taking comments on a level as low as 60 ppb.
Business advocates are concerned about how the emission allowance will shift for mobile, area and stationary sources. Critics are also saying the EPA needs to be more specific about the controls that could deliver the required deductions. They do not agree with the EPA’s claim that current control policies will achieve the lower standard. “Significant” new controls will be needed, they argue, to meet the 65- to 70-ppb standard.
NOx emissions from non-electric-generating-unit boiler units at industrial facilities would be particularly hard-hit by the changes. Since utility-sector NOx control is reaching its limits and NOx has been tagged as a more important ozone precursor than VOCs in some areas, industrial facilities would likely be required to scale back NOx. In the worst-case scenario, some boilers would have to be scrapped prematurely or shut down.
Facility owners and boiler operators are also worried about how a new emission standard would impact their current boiler MACT projects. The Maximum Achievable Control Technology (MACT) compliance deadline is Jan. 31, 2016, so most boiler MACT projects are likely already in the construction and installations phases. What will they will do if their boilers are in compliance with MACT rules but their NOx levels are out of compliance because of a lower ozone standard?
Because air quality differs from state to state and region to region, a revised ozone standard would have a different impact on emission control, leaving some urban areas harder hit by the proposed reduction than others.
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