U.S. EPA Finalizes Reconsiderations to the Area Source Boiler MACT Rule

On September 14, 2016, the U.S. Environmental Protection Agency (U.S. EPA) took final action on the five issues raised by petitioners in their petitions for reconsideration of 40 CFR Part 63, Subpart JJJJJJ – National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers Area Sources [commonly referred to as the Area Source Boiler Maximum Achievable Control Technology (MACT) rule].  U.S. EPA first announced the notice of reconsideration on January 21, 2015.

Similar to U.S. EPA’s response to petitioner’s issues raised relative to 40 CFR Part 63, Subpart DDDDD (the Major Source Boiler MACT rule), U.S. EPA removed the affirmative defense provisions from the Area Source Boiler MACT rule, citing the April 2014 Natural Resources Defense Council (NRDC) vs. U.S. EPA court ruling.  In addition, there were a number of technical corrections and other minor clarifications made to the rule.

This post provides a summary of the final U.S. EPA decisions on the five issues up for reconsideration that we outlined in our previous blog post.

Definitions of “Startup” and “Shutdown”

Consistent with U.S. EPA’s actions relative to the Major Source Boiler MACT rule, U.S. EPA finalized an alternate definition of “startup” to more clearly define when startup ends.  Specifically, the alternate definition states that startup ends four hours after the boiler supplies “useful thermal energy” (i.e., steam or hot water that meets the minimum operating parameters required for use) or produces electricity.  As we described in our previous blog, facilities that rely on this alternate definition will need to implement additional recordkeeping procedures for demonstrating compliance with the 4-hour extended startup period.  U.S. EPA also amended the definition of “shutdown” to incorporate the term “useful thermal energy” to more clearly define when shutdown begins.  These amended definitions are meant to better define when a boiler achieves steady-state operating conditions.

Particulate Matter (PM) Standard Exemptions for Oil-Fired Boilers

If you operate an oil-fired boiler, rated at 10 million British thermal units per hour (MMBtu/hr) or greater, that fires low-sulfur oil (i.e., less than 0.5% sulfur by weight), your boiler was previously exempt from the PM emissions limit.  However, beginning three years from the publication of these final revisions (i.e., September 14, 2019), your boiler now becomes subject to the applicable PM emissions limit in Table 1 of the Area Source Boiler MACT rule.  PM performance testing to demonstrate compliance is due 180 days after the emissions limit becomes effective (i.e., by March 12, 2020).

With this action, U.S. EPA has replaced the low-sulfur oil exemption with an exemption for oil-fired boilers that combust ultra-low-sulfur oil [i.e., less than or equal to 15 parts per million (ppm) sulfur].  In consideration of the comments received to the proposed revisions and review of available data, U.S. EPA concluded that boilers combusting oil containing 15 ppm of sulfur or less would not emit PM in excess of the potentially applicable PM emissions standards.  Therefore, if you operate an oil-fired boiler, rated at 10 MMBtu/hr or greater, that fires ultra-low-sulfur oil, you are exempt from having to meet a PM emissions limit and from having to conduct PM performance testing on the boiler.  However, if you start burning a new fuel type besides ultra-low-sulfur liquid fuel or gaseous fuels, a new performance test is required within 60 days.

Limited-Use Boiler Subcategory

Objections were raised by petitioners to the limited-use boiler subcategory (for boilers with a Federally-enforceable annual capacity of no more than 10%) in the original rule.  Boilers meeting these criteria were only subject to 5-year boiler tune-up requirements and were not subject to any additional emissions limitations or work practice standards.  U.S. EPA, in consideration of the comments received by petitioners, disagreed with the objections raised to the limited-use subcategory.  Due to the unpredictable operation of these boilers, U.S. EPA maintains that it is infeasible to conduct emissions testing and more frequent tune-ups would be difficult to schedule.  Therefore, U.S. EPA did not amend any of the existing requirements for limited-use boilers that were finalized in the February 2013 amendments to the Area Source Boiler MACT rule.

PM Performance Testing Requirements for Certain Boilers

U.S. EPA now requires PM performance testing every five years if, during your initial performance test, PM emissions from the boiler were less than or equal to half of the applicable PM emissions limit.  Previously, U.S. EPA did not require retesting of a boiler if the initial demonstration was below this threshold.  If you have already demonstrated that your PM emissions are less than half of the applicable limit, you have five years from the publication of these final revisions to conduct the next performance test (i.e., by September 14, 2021).  However, if you start burning a new fuel type in between 5-year tests a new performance test is required within 60 days, unless that new fuel is ultra-low-sulfur liquid fuel or gaseous fuels (because new or reconstructed boilers that combust only ultra-low-sulfur liquid fuel are not subject to the PM emissions limit and gas-fired boilers are exempt from the Area Source Boiler MACT rule).  This action does not change your PM performance testing obligations if the initial performance test results in PM emissions greater than half of the applicable PM emissions limit (i.e., you still must conduct testing every three years).

Fuel Sampling Requirements for Coal-Fired Boilers

U.S. EPA is requiring additional fuel sampling for mercury (Hg) based on the initial compliance demonstration for coal-fired boilers.  If the initial sampling demonstrates that Hg in the fuel mixture is less than or equal to half of the applicable Hg emissions limit, further fuel sampling is now required every 12 months thereafter.  Previously, U.S. EPA did not require retesting of a fuel mixture if the initial sampling was below the threshold.  If you have already demonstrated that Hg levels in your fuel mixture are less than half of the applicable limit, you have 12 months from the publication of these finalized reconsiderations to conduct the next round of fuel sampling (i.e., by September 14, 2017).  Additional fuel sampling is required before burning any new fuel type.  This revision does not change the quarterly fuel sampling obligations if the initial sampling results are greater than half of the applicable Hg emissions limit.

If you have questions about how these reconsiderations will affect you, please reach out to me at (610) 933-5246, extension 155, or at cchinofsky@all4inc.com.