EPA Publishes Final Reconsideration for Boilers at Area Sources



On September 14, 2016, EPA released its final publication in the Federal Register for the 2013 final amendments to NESHAP Subpart 6J (Area Sources of Industrial, Commercial and Institutional Boilers) addressing the following five issues. In addition to the final reconsideration changes on these remaining issues, minor typographical error corrections, removal of previous amendment changes, and reporting consistency updates were incorporated in the final reconsidered rule.

  1. Limited-use Boiler Subcategory.   Consistent with the February 2013 final rule, EPA is retaining the subcategory and separate requirements for limited-use boilers. A limited-use boiler is any boiler that burns any amount of solid or liquid fuels and has a federally enforceable annual capacity factor (ratio of actual heat input to potential heat input – if operated continuously at maximum steady state design heat input capacity) of no more than 10 percent.  
  2. Alternative Particulate Matter (PM) Standard for New Oil-Fired Boilers Combusting Low-Sulfur Oil.   EPA has determined that burning ultra-low-sulfur liquid fuel adequately controls urban metal HAP emissions. As a result, EPA finalized an alternative PM standard specifying that new or reconstructed oil-fired boilers with heat input capacity of 10 MMBtu/hr or greater that combust only ultra-low-sulfur liquid fuel must meet GACT for PM providing the type of fuel combusted is monitored and recorded on a monthly basis. Such boilers will not be subject to the PM emission limit in Table 1 of Subpart 6J. If a facility burns a fuel other than ultra-low-sulfur liquid fuel or gaseous fuels, a performance test must be completed within 60 days of burning the new fuel. New or reconstructed oil-fired boilers that commenced construction or reconstruction on or before publication of the final recon-sideration, and that are currently meeting the alternative PM standard for low-sulfur oil burning boilers, are provided three years from publication before becoming subject to the PM emission limit, providing the facility time to decide how to comply (i.e., combust only ultra-low-sulfur liquid fuel or conduct a performance test demonstrating compliance). 
  3. Elimination of Further PM Performance Testing.   Based on initial compliance testing, if PM emissions are equal to or less than half of the applicable PM emission limit, the facility does not need to conduct further performance testing for five years (no more than 61 months after the previous performance testing). The unit must continue to comply with all applicable operating limits and monitoring requirements.If subsequent performance testing indicates PM emissions are greater than half of the applicable PM emission limit, the facility must conduct subsequent performance testing on a triennial basis. 
  4. Elimination of Further Fuel Sampling for Mercury (Hg) for Coal-Fired Boilers.   Based on initial compliance demonstration using fuel analysis for Hg emissions that are equal to or less than half of the applicable Hg emission limit, the facility does not need to conduct further fuel analysis for one year (no more than 13 months after the previous fuel analysis). The unit must continue to comply with all applicable operating limits and monitoring requirements.If subsequent annual fuel analysis indicates Hg emissions are greater than half of the Hg emission limit, the facility must conduct subsequent fuel analyses on a quarterly basis. 
  5. Definition of Startup and Shutdown Periods.   The startup definition was updated to match (with the exception of excluding process heaters that are not regulated under NESHAP Subpart 6J) the definition included in NESHAP Subpart 5D (Boiler MACT) with regard to two parts: 1) startup ends when any of the useful thermal energy or heat from the boiler is supplied; 2) startup ends four hours after the boiler supplies useful thermal energy. The shutdown definition is also updated to match (with exception of excluding process heaters that are not regulated under NESHAP Subpart 6J) the definition included in Boiler MACT. Shutdown commences when the boiler no longer supplies useful thermal energy or when no fuel is being fed to the boiler, whichever is earlier. Shutdown ends when the boiler no longer supplies useful thermal energy and no fuel is being combusted in the boiler. Useful thermal energy means energy (i.e., steam or hot water) that meets the minimum operating temperature, flow, and/or pressure required by any energy use system that uses energy provided by the affected boiler. No Startup Shutdown Plan (SSP) is required in NESHAP Subpart 6J if a facility uses startup definition (2), which is a plan requirement for boilers at major sources under Boiler MACT.  

The final reconsidered NESHAP Subpart 6J reduces the compliance burden for industry regarding testing and fuel analysis requirements for a number of affected sites. Additionally, the updated startup and shutdown definitions provides further clarity and flexibility for startup periods when compliance demonstration is required for NESHAP Subpart 6J limitations. Review the final rule final rule here.