Maryland coal plants emerge untouched from regional haze program

Due to factors like already-in-place air limits under the 2007 Maryland Healthy Air Act and the fact there are no Class I protected areas in Maryland, the state has gotten off relatively lightly when it comes to new impacts on coal-fired power plants under the U.S. Environmental Protection Agency’s regional haze program.

In a Feb. 28 Federal Register notice, EPA proposed to approve a revision to the Maryland State Implementation Plan (SIP) submitted by the Maryland Department of the Environment. This revision addresses the requirements of the Clean Air Act (CAA) and EPA’s rules that require states to prevent any future, and remedy any existing, anthropogenic impairment of visibility in mandatory Class I areas caused by emissions of air pollutants from numerous sources located over a wide geographic area. States are required to assure reasonable progress toward the national goal of achieving natural visibility conditions in Class I areas. Comments on the proposed approval are being taken until March 29.

Maryland relied on various existing air programs, like the Maryland Healthy Air Act (HAA), which mandated steep emissions reductions from coal-fired power plants in the state, and emission reductions from various federal Maximum Achievable Control Technology (MACT) rules, to meet the regional haze requirements.

In order to address a timely implementation of Best Available Retrofit Technology (BART) rules under the regional haze program, the Maryland Healthy Air Act was determined to be better than BART for NOx and SO2 emissions. The first phase of the Healthy Air Act emission limits became effective in the 2009/2010 timeframe and the second phase will become effective in the 2012/2013 timeframe.

Maryland’s Brandon Shores Units 1-2, C.P. Crane Units 1-2, Chalk Point Units 1-2, Dickerson Units 1-3, Wagner Unit 3 and Morgantown Units 1-2 are twelve of the 167 units identified as having the highest emissions in the eastern U.S. The 2002 base year SO2 emissions from these twelve units are 235,435 tons per year. A 90% SO2 emission reduction from these twelve units would result in a reduction of 211,892 tons per year. “However, the SO2 emission reductions that have already resulted from the implementation of the Maryland HAA for these twelve units are 257,741 tons per year,” EPA noted. “These reductions are more than enough to satisfy the 90% emission reduction from the 2002 baseline requirements.”

Maryland at one point identified seven BART eligible sources (consisting of ten emission units). However, it was later determined that Mettiki Coal Corp., which is an Alliance Resource Partners unit with a coal mining operation in western Maryland, should not be included in the BART-eligible list since the source was not in existence by Aug, 7, 1977, which is a statutory cut-off date.

The HAA affects Maryland’s largest coal-burning power plants, which accounts for 95% of the state’s power plant emissions and requires year-round emission controls. The HAA does not allow facilities to obtain out-of-state emissions allowances in lieu of adding pollution control locally. During the first phase of the HAA, NOx emissions were reduced by approximately 70% in 2009 and SO2 emissions were reduced by approximately 80% in 2010. At full implementation, the HAA will reduce NOx emissions by around 75% in 2012 from 2002 levels and SO2 emissions will be reduced by about 85% in 2013 from 2002 levels.

Of the fifteen units subject to Maryland’s HAA, six have been identified as BART units. The HAA incorporates emissions limitations based on a suite of emission reduction technology capabilities. Maryland did a comparison of the HAA emission limits for thirteen of the fifteen units regulated by this rule to the BART presumptive limits for the seven BART subject units. This comparison resulted in a surplus of 60,805 tons of SO2 and 16,184 tons of NOx, primarily because the HAA emission limits are applicable to more units than the Maryland BART subject units.

Even particulates not a big probem for coal plants

For particulate matter (PM), which wasn’t covered by the HAA, Maryland required the BART facilities to conduct an analysis of potential BART control. However, five of the units have already installed high efficiency electrostatic precipitators (ESP) to control PM and one has already installed a fabric filter. The remaining unit has an enforceable operational restriction requiring the burning of natural gas for 95% of the total heat input during ozone season. With this existing fuel restriction, it will reduce PM emissions by approximately 90% during ozone season.

  • Chalk Point Unit 1 is a 355-MW, wall fired, dry bottom, supercritical boiler with coal as the primary fuel. This unit is equipped with a cold side ESP to control PM emissions by over 99.5%.
  • Chalk Point Unit 2 is also a 355-MW, wall fired, dry bottom, supercritical boiler with coal as the primary fuel. This unit is also equipped with a cold side ESP to control PM emissions by over 99.5%.
  • Chalk Point Unit 3 is a 640-MW, tangentially fired, sub-critical unit that fires residual fuel oil or natural gas. This cycling unit has operated at an average annual capacity factor of 5% from 2006 to 2009. A consent order requires this unit to operate 95% of the time using natural gas during ozone season (May-September). Since this unit operates primarily during ozone season, the operational restriction on fuel use effectively limit PM emissions by 90%.
  • Morgantown Unit 1 is a 630-MW, tangentially fired, supercritical boiler with coal as the primary fuel. This unit is equipped with a cold side ESP to control PM emissions by over 99.5%.
  • Morgantown Unit 2 is also a 630-MW, tangentially fired, supercritical boiler with coal as the primary fuel. This unit is also equipped with a cold side ESP to control PM emissions by over 99.5%.
  • Crane Unit 2 is a 200-MW utility boiler fired by four cyclone burners with coal as the primary fuel. This unit is equipped with a fabric filter to control PM emissions by over 99%.
  • Wagner Unit 3 is a 350-MW, supercritical once-over coal fired boiler. This unit is equipped with a cold side ESP to control PM emissions by over 99%.

Maryland has determined that existing controls for PM meet the BART requirement for all of these units since they reduce PM emissions, are cost efficient, and have no significant energy or non-air quality environmental benefit. EPA agreed with Maryland’s PM BART determination for all of the BART-affected electric generating units.

Chalk Point and Morgantown are controlled by GenOn Energy (NYSE:GEN), while Crane and Wagner are currently controlled by Constellation Energy (NYSE:CEG).

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.