On December 20, 2012, the US EPA issued final changes to Clean Air Act standards for major and area source boilers and commerical/industrial solid waste incinerators.
For Area Source Facilities (Boiler GACT): The final adjustments do not change the intended coverage of the air toxics standards for industrial, commercial, and institutional boilers and will not affect the estimated emission reductions, control costs or the benefits of the standards in substance. The adjustments do not impose any additional regulatory requirements beyond those imposed by the previously promulgated boiler area source standards and, in fact, will afford relief to some boilers.
EPA is issuing adjustments to the March 2011 standards based on evaluation of additional information provided to the agency since that time, including the following key changes:
-
Extending by two years the initial compliance date for existing area source boilers subject to the tune-up requirement.
-
Revising the deadline for initial notification for existing area source boilers to no later than January 20, 2014.
-
Revising provisions for existing dual-fuel fired units that fuel switch from gas to coal, biomass or oil such that they would still be considered existing sources.
-
Providing subcategories for seasonally-operated boilers and limited-use boilers.
-
Requiring tune-ups every five years, instead of every two, for certain area source boilers: seasonally-operated units, limited-use units, small oil-fired units and units with oxygen trim systems.
-
Clarifying that temporary boilers and residential boilers are not part of the source categories being regulated.
-
Revising particulate matter (PM) emission limit requirements such that combustion of oil meeting certain sulfur content requirements by new oil-fired boilers is considered an alternative method of meeting the PM emission standard and that such units are not required to meet the PM emission limit.
-
Reducing the fuel sampling and performance testing requirements such that after demonstration of initial compliance, under certain circumstances, further fuel sampling for boilers subject to a mercury emission limit and further PM performance testing for boilers subject to a PM emission limit is not required.
-
Providing the option of continuous emissions monitoring to demonstrate continuous compliance with the carbon monoxide (CO) emission limit.
-
More clearly defining the scope of the energy assessment and allowing for more streamlined assessments, including allowing sources already operating under certain energy management programs to satisfy the assessment requirement.
For Major Source Facilities (Boiler MACT): Existing sources must comply with the standards 3 years from the date of publication of the final revised standards, and if needed, may request an additional year.
With these adjustments, the EPA is:
-
Adding new subcategories for light and heavy industrial liquids to reflect design differences in the boilers that burn these fuels.
-
Adding new emission limits for particulate matter (PM) that are different for each biomass fuel subcategory to better reflect emissions during real‐world operating conditions.
-
Adding new emission limits for carbon monoxide (CO) based on newly submitted data that shows CO emissions from boilers vary greatly. EPA is setting new limits to more adequately capture that variability.
-
Allowing alternative total selective metals emission limits to regulate metallic air toxics instead of using a PM as a surrogate, allowing more flexibility and decreasing compliance costs for units that emit low levels of HAP metals.
-
Replacing numeric dioxin emission limits with work practice standards to reflect a more robust analysis that shows dioxin emissions are below levels that can be accurately measured.
-
Increasing flexibility in compliance monitoring by adding alternative monitoring approaches for demonstrating continuous compliance with the PM limit.
-
Adjusting PM and CO emission limits for units located outside the continental United States to reflect new data and to better reflect the unique operating conditions associated with operating these units.
-
Continuing to allow units burning clean gases to qualify for work practice standards instead of numeric emission limits. EPA is removing the hydrogen sulfide (H2S) fuel specification from the rule because it does not provide a direct indication of potential hazardous air pollutants (HAP) from combustion of gaseous fuel. Instead, mercury content alone is being used to determine clean gas.