Amidst the usual storm of protest and praise for a sweeping air initiative like this one, the U.S. Environmental Protection Agency on Dec. 21 issued the long-awaited Mercury and Air Toxics Standards (MATS), the first national standards covering power plant emissions of mercury and toxic air pollution like arsenic, acid gas, nickel, selenium, and cyanide.
The standards will slash emissions of these pollutants by relying on widely available, proven pollution controls that are already in use at more than half of the nation’s coal-fired power plants, EPA noted. A range of widely available and economically feasible technologies, practices and compliance strategies are available to power plants to meet the emission limits, including wet and dry scrubbers, dry sorbent injection systems, activated carbon injection systems, and fabric filters, EPA noted.
MATS, also often referred to as the Maximum Achievable Control Technology (MACT) rule, applies to electric generating units larger than 25 MW that burn coal or oil. These include investor-owned units, as well as units owned by the federal government, municipalities, and cooperatives that provide electricity for commercial, industrial, and residential uses. EPA estimated that there are about 1,400 units affected by this action, made up of about 1,100 existing coal-fired units and 300 oil-fired units at about 600 power plants.
“By cutting emissions that are linked to developmental disorders and respiratory illnesses like asthma, these standards represent a major victory for clean air and public health – and especially for the health of our children,” said EPA Administrator Lisa Jackson. “With these standards that were two decades in the making, EPA is rounding out a year of incredible progress on clean air in America with another action that will benefit the American people for years to come. The Mercury and Air Toxics Standards will protect millions of families and children from harmful and costly air pollution and provide the American people with health benefits that far outweigh the costs of compliance.”
Jackson, when talking about progress in 2011, was in part referring to the Cross-State Air Pollution Rule for NOx and SO2 emissions, issued in July and due to go into effect in January 2012. Executives in the power and coal industries warn that a combination of MATS, CSAPR and other rules that EPA has in place or in progress will force the shutdown of over 50 GW of coal-fired capacity by 2020. EPA, on the other hand, estimates that manufacturing, engineering, installing and maintaining the pollution controls to meet the MATS standards will provide employment for thousands, potentially including 46,000 short-term construction jobs and 8,000 long-term utility jobs.
Power plants are the largest remaining source of several toxic air pollutants, including mercury, arsenic, cyanide, and a range of other dangerous pollutants, and are responsible for half of the mercury and over 75% of the acid gas emissions in the United States. Currently, more than half of all coal-fired power plants already deploy technologies that will help them meet these standards, EPA said. Once final, the MATS standards will level the playing field by ensuring the remaining plants – about 40% of all coal-fired power plants – take similar steps to decrease pollutants.
As part of the commitment to maximize flexibility under the law, the standards are accompanied by a Presidential Memorandum that directs EPA to use tools provided in the Clean Air Act to implement MATS in a cost-effective manner that ensures electric reliability. For example, under these standards, EPA is not only providing the usual three years for compliance, but also encouraging permitting authorities to make a fourth year broadly available for technology installations, and if still more time is needed, providing a well-defined pathway to address any localized reliability problems should they arise.
MATS is in keeping with President Obama’s Executive Order on regulatory reform, EPA added. These standards are based on the latest data and provide industry significant flexibility in implementation through a phased-in approach and use of existing technologies. The regulations were issued under a consent decree of the D.C. Court of Appeals requiring EPA to issue a proposal by March 16, 2011, and a final rule by Dec. 16, 2011. Jackson signed the rule on Dec. 16 and unveiled it on Dec. 21.
EPA makes changes to ease industry concerns
EPA said it made several major changes in this final version of the rule from an earlier proposed version. For example, the final emission limit for filterable particulate matter (PM) – instead of total PM ‐ is issued as a surrogate for non‐mercury metallic air toxics. EPA had proposed an emission limit for total PM, which includes both filterable PM and condensable PM. The agency is finalizing a filterable PM limit, which is consistent with its approach in other toxics rules. This is appropriate because most of the metallic air toxics consist of filterable PM, and the one that is not – selenium ‐ is well controlled by the limit on acid gases, EPA noted.
Another change is the definition of subcategories for coal units, with the agency clarifying the subcategory definitions to make sure that the right units were covered in each category. The definitions, as proposed, were not specific enough and would have caused confusion about which limits applied to which units.
EPA said it received data that showed subcategories were appropriate for non-continental oil‐fired units located outside the continental U.S. and for oil‐fired units that are only used for very limited amounts of time. Non‐continental units are in a subcategory because their emissions characteristics are distinct and they have limited access to alternative fuel sources. These units need to meet different emission limits than continental units. Limited‐use units are in a subcategory because they run infrequently. Limited‐use units will minimize emissions by following work practice standards during the rare times when they do operate, avoiding the need to run just to meet monitoring requirements.
EPA adjusted several of its monitoring and record-keeping requirements to help streamline the process and reduce costs. Most significantly, the final rule simplifies the procedures for demonstrating continuous compliance to two options: continuous monitoring or periodic quarterly testing. Also, the rule clarified that sources are only required to do testing for the form of the limit they choose to meet.
Because it wasn’t feasible to set an emission limit during periods of start‐up and shut‐down, the final rule sets work practice standards instead. These standards require units to burn clean fuels such as natural gas or distillate oil during startup and shutdown to minimize emissions which will minimize toxics during these times.
EPA had proposed to give facilities the option to use facility‐wide averaging to meet the limits for mercury. The final rule clarifies that facilities may use a longer averaging time for mercury of 90 days instead of 30 days, but if they choose this option they will have to meet a tighter standard (1.0 lbs/TBtu). This will make the averaging option more useful to sources while providing equivalent reductions in mercury emissions.
The agency said it reviewed and revised some of the standards for new sources based on additional data submitted during the comment period. The final limits for new sources reflect emission levels EPA would expect to see from a newly constructed source equipped with a full suite of state‐of‐the‐art controls.
EEI says changes not enough to protect the grid
In a Dec. 21 statement, Edison Electric Institute President Tom Kuhn said: “EPA’s MACT rule is the most expensive rule in the agency’s history. It will require a significant number of electric generating units to design, obtain approval for and install complex controls or replacements in a very short timeframe. In some cases, it will mean that new transmission and natural gas pipelines will have to be built.”
Kuhn admitted that EPA has made useful technical changes from its original proposal. “Nevertheless, we believe the Administration is underestimating the complexity of implementing this rule in such a short period of time, which can create reliability challenges and even higher costs to customers,” he added. “The Administration is not using all the available authorities in the Clean Air Act to coordinate implementation, to ensure electric reliability, and to avoid excessive costs.”
EPA had a response to Kuhn’s concerns in a fact sheet that accompanied release of the rule. “EPA and the Department of Energy (DOE) analyses indicate that there will be more than enough electric generating capacity to meet the nation’s needs,” the sheet said. “EPA’s analysis projects that, as a result of MATS, 4.7 gigawatts (GW) will retire out of the more than 1000 GW that make up the nation’s electric generating capacity. That’s less than one half of one percent. Most of the generating capacity that is projected to retire is decades old and does not have modern pollution controls installed.”
EPA said it estimated that sources generally will have until early 2016 to comply – one year longer than its analysis indicates is necessary for most sources. EPA said it is also providing a clear pathway for units that are shown to be critical for reliability to obtain a schedule with up to an additional year to achieve compliance. EPA said it believes there will be few, if any, situations in which this pathway will be needed. In the unlikely event that there are other situations where sources cannot come into compliance on a timely basis, consistent with its longstanding historical practice under the Clean Air Act, the EPA will address individual noncompliance circumstances on a case‐by‐case basis to determine the appropriate response and resolution.