On December 21, 2012, EPA finally completed its reconsideration of four regulations designed to address hazardous air pollutant (“HAP”) emissions from industrial boilers and waste incinerators.  The rules are long overdue, considering that a court ordered EPA to finalize the rules in February 2011 and EPA itself promised to release the rule in April 2012.  However, because the final rules reduce the stringency of many of the emission limits that will be imposed on industrial boilers and extends the deadline for compliance until early 2016, the revisions will likely be welcome news for most of the industry subject to the new standards.

Of the four regulations, the “major source” Maximum Achievable Control Technology (“MACT”) standard for industrial boilers is generally of greatest interest because it applies stringent emission limits on boilers at larger facilities that have the potential to emit greater than 10 tons per year of any single HAP or 25 tons per year or more of all HAP emitted.  The limits in the final rule are complicated, due to the subdivision of “boilers” into 19 subcategories, but the benefit of that subcategorization is that it enabled EPA to take into account the different emission characteristics of each subcategory in establishing the limits.  All told, the rule contains over 100 different emission limits because EPA established numeric limits for 4 pollutants (particulate matter, carbon monoxide, hydrogen chloride, and mercury) for both new and existing units in all but 3 of the subcategories.  Almost all of those limits are now less stringent since EPA’s original June 2010 proposal.  However, many of the limits are more stringent than either EPA’s final March 2011 rule or its proposed reconsideration released just over a year ago.  In addition, many questions remain unanswered, since EPA expressly refused to respond to 57 specific issues raised during the comment period for its December 2011 reconsideration proposal.

In contrast, EPA’s boiler MACT for the smaller “area” sources imposes much fewer and less stringent emission limits – generally only for larger boilers within the area source category utilizing coal as a primary fuel.  The rule raises fewer questions as well, since the rest of the boilers covered under the area source rule need only conduct periodic tune-ups to ensure emissions are minimized using good combustion practices.  Also, like previous versions of the rule, natural gas units continue to be entirely exempt from the “area” source boiler MACT.

In addition to boilers, EPA’s four-rule package also addressed another type of source altogether – waste incinerators – through its new source performance standards and emission guidelines for “Commercial and Industrial Solid Waste Incinerators” (“CISWI”).  Although referred to as a “new source performance standard” and an “emissions guideline,” the standards still represent a “MACT” level of control, and address 9 different pollutants emitted from new and existing incinerators.  Because the Clean Air Act requires boilers to be regulated as a waste incinerator if it burns “any” solid waste, EPA also adopted a new rule along with its 2011 rule package to help differentiate between the two source categories.  In particular, EPA felt additional clarification was needed for units that combust “secondary materials” that walk the line between a “waste” and a “fuel.”  EPA agreed to reconsider this “non-hazardous secondary materials” rule along with the reconsideration of the boiler and incinerator regulations to ensure all four rules remain consistent, but made only minimal changes in the final rule just released.

A copy of the “major source” MACT rule is available here.

A copy of the “area” source MACT rule is available here.

A copy of the CISWI rule is available here.