The long-awaited EPA revisions to the Boiler MACT rules are now final. The Boiler MACT rules are promulgated to regulate air emissions at affected boilers and process heaters at major hazardous air pollutant (HAP) sources, and also for affected boilers at minor (area) HAP sources, respectively, at:
- 40 CFR 63 Subpart DDDDD (National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial, and Institutional Boilers and Process Heaters)
- 40 CFR 63 Subpart JJJJJJ (National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial, and Institutional Boilers)
On December 20, 2012, EPA released a prepublication version of both the major source Boiler MACT rule revisions and the area source Boiler MACT rule revisions. On January 31, 2013, EPA published the final revised major source Boiler MACT rule in the Federal Register. The amendments in this rule to 40 CFR Part 63 Subpart DDDDD are effective as of April 1, 2013. It is expected that EPA will soon publish in the Federal Register the final area source Boiler MACT rule amendments.
After a greater than 10-year rulemaking and litigation saga – the original Boiler MACT rule was proposed on November 26, 2002 – it seems fitting that the major source Boiler MACT rule effective date will be April 1, 2013.
Major Source Boilers
From a big picture perspective, compliance will be far easier and much less expensive for gas-fired (natural gas, LPG or propane) boilers at major source facilities. A new or existing natural gas-fired boiler will have no emission limits, no fuel analysis, no stack testing and no need for new air pollution control devices.
Both new and existing coal, biomass and oil-fired boilers will be subject to multiple emission limits (Hg, HCl, CO and PM or TSM).
An existing coal-fired boiler would need at least a control device for PM, and potentially additional control devices for Hg and/or HCl if compliance cannot be reliably demonstrated by fuel analysis or stack testing. Compliance with the CO limit would need to confirmed by stack testing.
Compliance may be easier and less expensive for a distillate oil-fired boiler because it could likely demonstrate compliance with Hg and HCl via fuel analysis, and likely comply with the PM and CO limits by stack testing, without the need for an added control device.
A primary consequence of this rule, whether intended by EPA or not, is likely to be fuel-switching from solid fuel (coal, wood, other biomass) chiefly to natural gas fuel, or secondarily to distillate oil fuel. This is especially true for older, less efficient boilers that burn solid fuel, and may also be a concern for existing boilers that combust heavy oil. The cost to retrofit new air pollution control devices (scrubbers, oxidizers, baghouses, new burners, etc) to existing boilers may be more expensive than replacing the boiler with a new boiler that is fueled by natural gas or distillate oil.
Beyond the potentially significant initial capital costs, cost of fuel and on-going operational costs, the Boiler MACT rules require enhanced boiler and control device maintenance/tune-ups, data monitoring, recordkeeping and reporting to EPA and state/local air agencies.
Area Source Boilers
New and existing gas-fired boilers are exempt from regulation under 40 CFR 63 Subpart JJJJJJ. Existing oil-fired boilers will have no emission limits, no fuel analysis and no stack testing, whereas new oil-fired boilers (>10 MMBtu/hr) will have a particulate matter emission limit for which compliance must be demonstrated.
New solid fuel (coal, wood, biomass) boilers (>10 MMBtu/hr) will have multiple emission limits for which compliance must be demonstrated by either fuel analysis or stack testing, and may require new or upgraded air pollution control devices and monitoring systems. Existing coal-fired boilers (>10 MMBtu/hr) will have a particulate matter emission limit for which compliance must be demonstrated.
All existing area source facilities having an affected boiler >10 MMBtu/hr will require the performance of a one-time energy assessment by qualified personnel on the affected boilers and energy use system to identify any cost-effective energy conservation measures (cost effective means items having a payback period of 2 years or less). Subpart JJJJJJ also requires periodic tune-ups of several of the various types of affected source boilers.
For further details on the Boiler MACT rules, see the following. The Council of Industrial Boiler Owners (CIBO) provides on their web site some excellent summaries of the revised Boiler MACT rules, plus an EPA presentation on the topic.
Federal Register 78:21 (31 January 2013) pp. 7138-7213.
This article was partially excerpted from publically available information, and was authored by Rick Wilson, Acacia Environmental Group LLC. Any opinions expressed in this article are those solely of the author, and are not intended as legal or professional guidance to any specific readers. For more information on the author see here.