2 min read

New Boiler MACT Rule Proposed—Changes and Next Steps

After years of legal and regulatory uncertainty, the US Environmental Protection Agency (EPA) may be on the verge of a final decision regarding the implementation of a provision of the Clean Air Act (CAA) known as the Boiler Maximum Achievable Control Technology (MACT) standard.

The first Boiler MACT rules were proposed by the EPA in 2004; these were quickly challenged by both industry and environmental groups. In 2007, the Washington DC District Court vacated the rules and directed the EPA to re-propose the rules, which it did in June of 2010. This proposed rule only increased opposition. So when the EPA released its final rule under court order in March 2011, it also announced that it would re-propose the rule later in the year.  The reconsideration rule was released by the EPA on Dec. 2. After a 60-day comment period, the agency intends to release the “final” final rule.

What does this latest rule mean for operators of industrial boilers and process heaters? The rule:

  • Eliminates emissions limits on dioxins/furans. The EPA found, after reviewing comments on the rule released in March, that these pollutants are emitted in amounts that are not accurately measurable using current technology. As a result, instead of measuring these pollutants, units will have to comply with work practice standards by having annual tune-ups.
  • Maintains strict limits on mercury, hydrogen chloride, particulate matter and carbon monoxide, though the limits vary by unit type.

—Mercury and hydrogen chloride: the new rule sets one limit for boilers using solid fuels and another for units using liquid fuels. Mercury limits are stricter than those in the previous rule.

—Particulate matter and carbon monoxide: The new rule sets limits that vary based on the type of unit (14 different unit types are specified, 7 of which are biomass).  Carbon monoxide limits are generally stricter than those in the previous rule; particulate matter limits are generally less strict.

  • Increases the flexibility in monitoring requirements.

—Mercury:  The new rule allows continuous monitoring as an option for  demonstrating compliance (rather than periodic testing and fuel sampling analysis).

—Hydrogen Chloride: The new rule allows continuous monitoring of sulphur dioxide to demonstrate compliance with hydrogen chloride limits, if a correlation can be proven.

—Particulate Matter: The previous rule required continuous monitoring systems for particulate matter at biomass-fired units; the new rule reverses this requirement. At other units, continuous monitoring will be used to determine compliance with operating, not emissions, limits.

  • Changes the measurement time frames. The new rule allows 30-day rolling averages instead of 12-hour block averages to determine compliance with operating limits.
  • Extends the timeline for compliance. The new rule requires compliance 3 years after the “final” final rule is published (expected March 2012).

While the final rule (and therefore the regulatory certainty that will accompany it) is one step closer, the costs of implementing the new rules remain to be seen. Achievability continues to be an issue as well, as tighter requirements for both mercury and hydrogen chloride are likely to present challenges for some operators.

Those affected by the rule will likely continue to push for additional changes using a two-pronged approach. The first is through the regulatory process. Once the proposed rule is published in the Federal Register (as of December 15, this has yet to happen), the 60-day comment period on the changes will begin. The EPA has been in retreat lately, due to increased political pressure, so there may be more ground to be gained in the “final” final rule as a result.

The other—though perhaps less likely—option is legislative. In October, the House passed the EPA Regulatory Relief Act of 2011. Among other things, this bill would delay the formulation of a “final” final rule for another 15 months and increase the compliance timeline from 3 years to 5 years. The Senate version of the bill has been placed on the legislative calendar, though it has not yet made it to committee. Even if the bill should make it through the Senate, it is unclear if the President will pick up a pen to sign the legislation into law or to veto it.