FACT SHEET Mercury and Air Toxics Standards: Final Subcategory of Certain Existing Electric Utility Steam Generating Units That Fire Coal Refuse ACTION • On April 9, 2020, EPA established a new subcategory in the Mercury and Air Toxics Standards (MATS) for certain existing power plants that fire a specific type of "coal refuse" Coal refuse includes low-quality coal mixed with rock, clay and other material. It is usually piled near coal mines. • The subcategory is for certain existing electric utility steam generating units (EGUs) firing eastern bituminous coal refuse (EBCR) and is only for emissions of acid gas hazardous air pollutants (HAP). • EPA recognizes that there are differences in the acid gas HAP emissions from EGUs firing EBCR and those firing other types of coal (including those firing other types of coal refuse, such as anthracite coal refuse). • After evaluating comments and data provided in response to a February 7, 2019 proposal, EPA has concluded that it is appropriate to establish such a subcategory and corresponding acid gas HAP emission standards. • The new subcategory and emission standards will affect six existing EGUs (all small units operating in Pennsylvania or West Virginia) that fire EBCR. These EBCR-fired EGUs have achieved the new emission standards without the need for downstream acid gas controls. • Although the new emission standards will allow higher acid gas HAP and SChemissions from these facilities compared to the emission standards in the original 2012 MATS, EPA does not expect emissions of other pollutants to change under this action. • Absent the new subcategory and emission standards, many affected EBCR-fired EGUs may choose to discontinue operations. Closure of the units would likely result in less removal of coal refuse piles, which are prone to spontaneous internal combustion (smoldering) and emit uncontrolled acid gases and other HAP. Removal of coal refuse piles reduces surface and groundwater pollution from acidic drainage. In addition, the alkaline ash produced as a by-product of these units is used to reclaim mining-affected lands. BACKGROUND • In 2011, EPA proposed a single acid gas emission standard for all coal-fired power plants using hydrochloric acid (HCI) as a surrogate for all acidic gas HAP, as well as an alternative emission standard for SO2 as a surrogate for the acid gas HAP. • Public comments on the proposal claimed that the characteristics of coal refuse made it too costly to comply with the acid gas HAP standards and requested a subcategory for EGUs firing all types of coal refuse. • EPA determined there was no basis for a subcategory and, in 2012, finalized HCI and SO2 standards that apply to all coal-fired EGUs. • EPA's decision was challenged, and, in 2014, upheld by the D.C. Circuit Court in White Stallion v. EPA. 1 ------- • EPA received a petition for reconsideration requesting a subcategory for the acid gas standards for EGUs firing all types of coal refuse, and EPA denied the petition. • EPA's denial of the petition was challenged, the petitioner claiming that its petition only requested subcategorization for EGUs firing bituminous coal refuse, not for all coal refuse EGUs (ARIPPA v. EPA). • In 2017, EPA asked the Court to hold the case in abeyance. • Based on a reevaluation of the data available when the 2012 MATS rule was established, in addition to data generated since promulgation of that rule, EPA recognizes that there are differences in the acid gas HAP emissions from EGUs firing EBCR and those firing other types of coal (including those firing other types of coal refuse, such as anthracite coal refuse) and, in a February 7, 2019 proposal, solicited comment on establishing a subcategory of certain existing EGUs firing EBCR for emissions of acid gas HAP. FOR MORE INFORMATION • A copy of the final rule and a fact sheet are available at https://www.epa.gov/mats. 2 ------- |