4 The record articles

Final Area Source Boiler MACT: The Gift That Keeps on Giving

Posted: January 18th, 2013

Author: All4 Staff 

4 Rules Friday is a series of four blog posts highlighting key aspects of the final 4 Rules (i.e., Major and Area Source Boiler MACT, Nonhazardous Secondary Materials, and Commercial and Industrial Solid Waste Incineration).  Please refer to the graphic for each blog’s posting date.

In part two of ALL4’s 4 Rules Friday series, we take a look at the Final Area Source Boiler MACT (40 CFR Part 63, Subpart JJJJJJ) and how the final rule may impact facilities.  As we all are well aware by now, U.S. EPA issued pre-publication versions of the final rules, including Area Source Boiler MACT, on December 20, 2012.  A number of the revisions to the final rule address the comments that U.S. EPA received regarding the December 23, 2011 proposed reconsideration of the Area Source Boiler MACT.  In particular, U.S. EPA established four new subcategories since the March 21, 2011 final version of the rule.  The subcategories for the final rule are as follows, with new categories noted in bold:

  • Coal
  • Biomass
  • Oil
  • Seasonal boilers – boilers that do not operate for at least seven consecutive months for each 12-month period and that fire only oil or biomass
  • Small oil-fired boilers – boilers with a heat input capacity of less than or equal to 5 MMBtu/hr
  • Boilers with an oxygen trim system – boilers that operate a continuous oxygen trim system and maintain an optimum air-to-fuel ratio
  • Limited-use boilers – boilers that fire solid or liquid fuels with an average annual capacity factor less than or equal to 10 percent

The final rule also identifies additional boilers that are excluded from the source categories above and, therefore, are not subject to the Area Source Boiler MACT.  These additional excluded boilers include electric boilers, residential boilers, and temporary boilers.  U.S. EPA also clarified language around exclusions for boilers with Section 3005 permits and boilers used as control devices.  To qualify as a boiler used as a control device, 50 percent or more of the heat input to the boiler must be provided by the gas stream being controlled, and the purpose of controlling the gas stream must be to comply with a requirement under 40 CFR Parts 60, 61, or 65.

The final rule also revised the applicability for dual-fuel fired boilers.  Any existing dual-fired boiler (i.e., commenced construction on or before June 4, 2010) that meets the definition of a gas-fired boiler per 40 CFR §63.11237 and meets the applicability criteria of Subpart JJJJJJ after June 4, 2010 due to a fuel switch from gaseous fuel to solid, biomass, or liquid fuel will be considered an existing source as long as the boiler was designed to accommodate the alternate fuel.  Similarly, any new or reconstructed boiler that meets the definition of a gas-fired boiler and meets the applicability criteria of Subpart JJJJJJ after June 4, 2010 due to a fuel switch from gaseous fuel to solid, biomass, or liquid fuel will still be considered a new source.

Mercury (Hg) and carbon dioxide (CO) emission limits for new and existing coal-fired boilers have been revised based on new information provided to U.S. EPA.  The Hg emissions limit for coal-fired boilers greater than or equal to 10 MMBtu/hr has been increased from 4.8E-6 to 2.2E-5 lb/MMBtu and the CO emissions limit has been increased from 400 to 420 ppmvd corrected to 3% oxygen.  Additionally, coal-fired boilers subject to a CO emission limit now have the option to comply using continuous emissions monitoring system (CEMS) data based on a 10-day rolling average.

The final rule also contains a number of changes related to work practice and management practice requirements.  For the new subcategories added to the final rule (i.e., seasonal boilers, small oil-fired boilers, boilers with oxygen trim systems, and limited-use boilers), U.S. EPA has established tune-up requirements.  However, the tune-ups are only required every five (5) years as opposed to the biennial tune-up requirements for coal-, biomass-, and oil-fired boilers.  The methodology for conducting tune-ups has also been updated in the final rule to provide more detail around the previously vague tune-up requirements.  This includes allowing for the use of portable CO analyzers to measure the concentration of CO in the effluent stream.  Additionally, the burner and air-to-fuel ratio inspections can be delayed until the first scheduled shutdown, and until the first outage for units that sell electricity so long as the time between inspections does not exceed 36 months.  Tune-ups shall be conducted within 30 days of startup for units that are not operating by the time the inspection is required.  The final rule has also been revised so that initial tune-ups are not required for new or reconstructed boilers.

U.S. EPA has also revised the definition of energy assessment for those facilities that are subject to the one-time energy assessment requirements.  The final rule clarifies that the energy assessment is limited to only those energy systems located on-site, associated with the affected boilers.  U.S. EPA further clarifies that the scope of the energy assessment is based on energy use by individual areas of the facility (i.e., production areas, lines, or buildings) and not by the total aggregation of all individual energy areas of a facility.  Also, all energy assessor approval and qualification requirements are waived for those energy assessments that were completed on or after January 1, 2008 to meet, or are amended to meet, the energy assessment requirements in the final rule by March 21, 2014.  If, by March 21, 2014, a facility is operating under an energy management program established through energy management systems compatible with ISO 50001 which includes the affected boilers, the energy assessment requirement is satisfied.

Fuel sampling requirements were revised for coal-fired units, in that if the Hg constituents of the fuel or fuel mixture are measured to be less than or equal to 50 percent of the Hg emission limit during the initial compliance demonstration, no further sampling is required.  If the constituents are measured to be greater than 50 percent of the emission limit, then quarterly sampling is required.  Performance testing requirements were similarly revised, in that if the particulate matter (PM) initial performance test results demonstrate that emissions are less than or equal to 50 percent of the PM emission limit, no further performance testing is required.  If the test results demonstrate that emissions are greater than 50 percent of the emission limit, then ongoing performance tests are required pursuant to 40 CFR §63.11220(a).

The initial compliance date of the final rule for existing affected boilers subject to an emissions limitation has not been revised and remains March 21, 2014.  Initial notification for existing affected boilers is now due by January 20, 2014.  The initial tune-up, previously required by March 21, 2012, is now required by March 21, 2014.  The Notification of Compliance Status (NOCS) regarding the initial tune-up requirement, previously due by July 19, 2012, is now due by July 19, 2014.  New sources (which remain defined as those that began operating on or after June 4, 2010) must be in compliance upon startup, except for new sources that began operation on or before May 20, 2011, which must have been in compliance by May 20, 2011. 

As mentioned above, all existing boilers subject to Subpart JJJJJJ must demonstrate initial compliance by March 21, 2014.  This means that there is not much time left for those facilities that must install a control device to comply with the Area Source Boiler MACT.  However, in the preamble of the final rule, U.S. EPA states that the Clean Air Act “allows Title V permitting authorities to grant sources, on a case-by-case basis, extensions to compliance time of up to 1 year if such time is needed for the installation of controls.”  So fear not, all hope is not lost if you are still a little late to the party.  However, all facilities must begin to act now because the compliance date will be here before we know it.  

The pre-publication version of the final rule can be found here.  Please refer to Susie’s blog post for information related to the final Major Source Boiler MACT.


    Sign up to receive 4 THE RECORD articles here. You'll get timely articles on current environmental, health, and safety regulatory topics as well as updates on webinars and training events.
    First Name: *
    Last Name: *
    Location: *
    Email: *

    Skip to content