RULES AND REGULATIONS
Title 25--ENVIRONMENTAL PROTECTION
ENVIRONMENTAL QUALITY BOARD
[25 PA. CODE CH. 123]
Standards for Contaminants; Mercury
[37 Pa.B. 883]
[Saturday, February 17, 2007]The Environmental Quality Board (Board) amends Chapter 123 (relating to standards for contaminants) to read as set forth in Annex A. The purpose of this final-form rulemaking is to establish ''State-specific'' requirements to reduce mercury emissions from coal-fired electric generating units (EGUs) with a nameplate rated capacity of 25 megawatts or more that produce electricity for sale. The final-form rulemaking establishes mercury emission standards, annual emission limitations as part of a Statewide annual nontradable mercury allowance program and monitoring, recordkeeping and reporting requirements to reduce mercury emissions from coal-fired EGUs or cogeneration units. This final-form rulemaking will be submitted to the United States Environmental Protection Agency (EPA) as an element of the State Plan required under section 111(d) of the Clean Air Act (CAA) (42 U.S.C.A. § 7411(d)).
This order was adopted by the Board at its meeting of October 17, 2006.
A. Effective Date
The final-form rulemaking will be effective upon publication in the Pennsylvania Bulletin.
B. Contact Persons
For further information, contact Krishnan Rama- murthy, Chief, Division of Compliance and Enforcement, Bureau of Air Quality, 12th Floor, Rachel Carson State Office Building, P. O. Box 8468, Harrisburg, PA 17105-8468, (717) 783-9476; or Robert ''Bo'' Reiley, Assistant Counsel, Bureau of Regulatory Counsel, 9th Floor, Rachel Carson State Office Building, P. O. Box 8464, Harrisburg, PA 17105-8464, (717) 787-7060.
C. Statutory Authority
This final-form rulemaking is adopted under the authority of section 5(a)(1) of the Air Pollution Control Act (APCA) (35 P. S. § 4005(a)(1)), which grants the Board the authority to adopt regulations for the prevention, control, reduction and abatement of air pollution.
D. Background and Summary
1. Legal and Regulatory History Regarding the Control of Mercury Emissions
Mercury is a highly toxic pollutant--one specifically targeted by Congress when, in 1990, it amended section 112 of the CAA (42 U.S.C.A. § 7412). The environmental impacts of mercury are significant, widespread and adverse.
Under the 1990 amendments to the CAA, Congress altered the principle focus of the hazardous air pollutants (HAPs) program under section 112 of the CAA from a health-based to a technology-based regulatory program. As part of this new regulatory focus, under section 112(b) of the CAA, Congress listed 189 HAPs. Those chemicals chosen to be regulated as HAPs under the CAA by Congress are especially harmful to public health and the environment. These chemicals are known to cause cancer, birth defects, lung disease, nervous system disorders, liver damage and other health problems. Many of these chemicals are also known to bioaccumulate in living organisms and become more concentrated at higher levels in the food chain.
Congress chose to regulate and reduce HAP emissions through a technology-based standard rather than a health-based standard because the former is more effective in reducing emissions. The control of HAPs through health-based standards by the EPA under the pre-1990 CAA amendments resulted in serial litigation with industry and regulatory paralysis at the agency. Moreover, the EPA had a difficult time conducting the necessary risk analysis and ambient air quality analysis to list pollutants and establish emission standards. As a result, Congress concluded that a technology-based approach was appropriate because routine and episodic releases of HAPs posed a significant threat to public health; the risk of adverse health effects related to these emissions were significant; and HAPs may cause significant environmental damage. See S. COMM. REP. NO. 101-228 at 132 (Report on S. 1630, Clear Air Amendments of 1989.)
Under section 112(c) of the CAA, the EPA was required to establish a list of all categories and subcategories of major and area sources of air pollution for those pollutants listed under subsection (b). For each listed category of sources, the EPA is required, under section 112(d) of the CAA, to promulgate standards requiring the installation of maximum achievable control technology (MACT) in light of economic, energy and environmental considerations.
The EPA is required to base the standard on the best technology currently available for the source category in question. These standards must be at least as stringent as the level achieved in practice by the best-controlled source in the source category for new sources or for the best performing group of sources for existing source MACT standards. For existing source MACT standards, the EPA defines the ''MACT floor'' (the minimum stringency level for existing source MACT) in terms of the central tendency (arithmetic mean or median) of the best 12% of sources in the source category (where there are 30 or more sources in the category) or the best performing 5 sources (where there are fewer than 30 sources in the category).
As part of this MACT process, the EPA has already finalized mercury emission limits for municipal waste combustors and medical waste incinerators, which resulted in a 90% reduction in mercury emissions within 5 years. However, Congress set forth additional regulatory steps before mercury emissions from EGUs could be controlled.
Under section 112(n)(1)(A) of the CAA, Congress directed the EPA to perform a study of the hazards to public health reasonably anticipated to occur as a result of emissions of HAPs by EGUs. Under this same subparagraph, the EPA is further directed to regulate these units if the agency finds regulation is appropriate and necessary after considering the results of the study.
In addition to this section of the CAA, section 112(n)(1)(B) of the CAA further directs the EPA to conduct a study of mercury emissions from EGUs, municipal waste combustion units and other sources to consider the rate and mass of these emissions, the health and environmental effects of these emissions, control technologies and the costs of these technologies.
In December of 1997, the EPA fulfilled the statutory directive of section 112(n)(1)(B) of the CAA when it issued its ''Mercury Study Report to Congress,'' EPA-452/R-97-003. This 1,800-page, 8-volume report discusses the National inventory of anthropogenic mercury emissions in the United States, the fate and transport of mercury in the environment, an assessment of exposure to mercury in the United States, health effects of mercury and mercury compounds, an ecological assessment for anthropogenic mercury emissions in the United States, characterization of human health and wildlife risks from mercury in the United States and an evaluation of mercury control technologies and costs.
On February 28, 1998, the EPA fulfilled its statutory obligation, under section 112(n)(1)(A) of the CAA, when it released its ''Study of Hazardous Air Pollutant Emissions from Electric Steam Generating Units--Final Report to Congress.'' This Utility Air Toxics Study issued in February 1998 evaluated EGUs that burn coal, oil or gas to generate electricity and are greater than 25 megawatts in size. This study includes the description of the utility industry; an analysis of air toxics emissions data from fossil-fuel (coal, oil and gas) fired utilities; an assessment of risks to public health from exposure to toxics emissions through inhalation; assessment of potential risks to the public health from exposure to four specific air toxics (radio nuclides, mercury, arsenic and dioxins) through other indirect means of exposure (for example, food ingestion, dermal absorption); a general assessment of the fate and transport of mercury through environmental media; and a discussion of alternative control strategies.
December 20, 2000, the EPA concluded, based upon the findings of its 1998 report and on information subsequently obtained, that in accordance with section 112(n)(1)(A) of the CAA, the regulation of mercury emissions from electric utilities was ''appropriate and necessary'' 65 FR 79825. As a result of these findings, the EPA added these units to the list of source categories to be regulated under section 112(c) of the CAA. The EPA was then required to establish emission standards for this source category under section 112(d) of the CAA.
The EPA published a final rule at 70 FR 15993 (March 29, 2005) entitled ''Revision of December 2000 Regulatory Finding on the Emissions of Hazardous Air Pollutants From Electric Utility Steam Generating Units and the Removal of Coal- and Oil-Fired Electric Utility Steam Generating Units From the Section 112(c) List.'' The EPA now believes that it is neither appropriate nor necessary to regulate mercury from these units under section 112 of the CAA.
As a result of this conclusion, the EPA removed coal- and oil-fired EGUs from the Section 112(c) list. This final action means that the EPA does not have to promulgate MACT standards for the control of mercury emissions from utility units. This action also cleared the way for the EPA to regulate these emissions under a Section 111 cap-and-trade approach.
On March 15, 2005, the EPA finalized the Clean Air Mercury Rule (CAMR). The final rulemaking published at 70 FR 28606 (May 18, 2005) established standards of performance for mercury for new and existing coal-fired EGUs as defined in section 111 of the CAA. New EGUs are subject to different standards of performance based on five subcategories--subbituminous, bituminous, lignite, waste coal or integrated gasification combined cycle (IGCC). The CAMR establishes a ''cap-and-trade'' program by which mercury emissions from new and existing coal-fired EGUs are capped at specified, Nationwide levels. The Phase 1 cap of 38 tons per year (tpy) becomes effective in 2010 and the Phase 2 cap of 15 tpy becomes effective in 2018. Facility owners and operators must demonstrate compliance with the standard by holding one ''allowance'' for each ounce of mercury emitted in any given year. Allowances will be readily transferable among all regulated facilities under the Section 111 trading scheme.
In response to the EPA's March 29, 2005, revision and the CAMR, petitions for review challenging these final agency actions were filed with the United States Court of Appeals for the D.C. Circuit. In addition to the Commonwealth, state challengers include California, Connecticut, Delaware, Illinois, Maine, Massachusetts, New Hampshire, New Mexico, New Jersey, New York, Rhode Island, Vermont and Wisconsin.
On May 31, 2005, the Commonwealth, together with the States of California, Connecticut, Delaware, Illinois, Maine, Massachusetts, New Hampshire, New Jersey, New Mexico, New York, Minnesota, Rhode Island, Vermont and Wisconsin, filed a petition for reconsideration under section 307(d)(7)(B) of the CAA (42 U.S.C.A. § 7607(d)(7)(B)) related to the EPA's March 29, 2005, final action revising its December 2000 regulatory finding. Issues related to this petition included, but were not limited to, whether the EPA's action is contrary to the CAA and supported by the record and whether the procedural requirements under the Administrative Procedures Act and the CAA were followed.
On July 18, 2005, the Commonwealth, together with these same states, filed a petition for reconsideration under section 307(d)(7)(B) of the CAA related to the CAMR. Issues related to this petition included, but were not limited to, the setting of new source performance standards (NSPS) standards based on subcategories of coal, the cost-benefit analysis, air quality modeling and provisions concerning the 2010 cap on mercury emissions.
On October 28, 2005, the EPA granted reconsideration on both petitions and reopened the public comment period related to certain issues under both final actions. See 70 FR 62200 and 62213 (October 28, 2005).
On December 19, 2005, the Commonwealth and the other states filed comments on these reconsideration actions. Issues related to these reconsideration notices included, but were not limited to, the EPA's legal interpretations, the EPA's methodology and conclusions concerning reasonably anticipated hazards to public health resulting from EGU mercury emissions, modeling of mercury deposition, costs, NSPS standards and statistical analysis used for the NSPS standards.
On June 9, 2006, after considering the petitions for reconsideration and the comments received, the EPA decided not to further revise the CAMR other than to explain in more detail what the agency meant by the effectiveness element in the term ''necessary'' 70 FR 33388. The only two substantive changes the EPA made to the CAMR in response to comments involve revisions to the state mercury allocations and to the NSPS. The EPA also finalized the regulatory text that clarifies the applicability of the CAMR to municipal waste combustors and certain industrial boilers. Finally, the EPA denied the requests for reconsideration with respect to all other issues raised in the petitions for reconsideration submitted for both rules.
Section 111(c) and (d) of the CAA requires each state to develop and submit to the EPA Administrator a procedure for implementing and enforcing the NSPS for new sources and emission guidelines for existing sources. Specifically, the EPA authorizes states, under the CAMR, to adopt the mercury cap-and-trade program whether by incorporating by reference the CAMR cap-and-trade rule that will be codified in 40 CFR Part 60, Subparts Da and HHHH (relating to standards of performance for electric utility steam generating units for which construction is commenced after September 18, 1978; and emission guidelines and compliance times for coal-fired electric steam generating units), or by codifying the provisions of the CAMR cap-and-trade rule, to participate in the EPA-administered mercury cap-and-trade program. The final CAMR establishes the Commonwealth's 2010-2017 mercury emissions budget as 1.77 tons and the 2018 budget as 0.702 ton.
Each state participating in the EPA-administered cap-and-trade program must develop a method for allocating an amount of allowances authorizing the emissions tonnage of the state's CAMR budget. Each state has the flexibility to allocate its allowances however it chooses, so long as certain timing requirements are met. States may elect to participate in the EPA-managed cap-and-trade program for coal-fired EGUs. However, state participation in this program is voluntary. For states that elect not to participate in the EPA-administered mercury cap-and-trade program, a methodology must be established by the states to meet the CAMR mercury emission budgets by reducing mercury emissions.
By November 17, 2006, states must submit a plan to the EPA to implement the requirements of the CAMR or a more protective program. If a state fails to submit a state plan, as required in the final rule, the EPA will prescribe a Federal plan for that state under section 111(d)(2)(A) of the CAA. The EPA would propose the model rule under the CAMR as that Federal plan. However, the EPA has indicated in the preamble to the final rule that states are free to develop a more stringent mercury control program than the one in the final rule.
The Department of Environmental Protection (Department) held three public hearings on the proposed State Plan for designated EGU facilities. See 36 Pa.B. 4269 (August 5, 2006). On September 6, 2006, public hearings were held at two Department regional offices in Norristown and Pittsburgh and at the Rachel Carson State Office Building in Harrisburg. This final-form rulemaking will be submitted to the EPA as the State Plan to fulfill the Commonwealth's requirements under the CAMR for new and existing EGUs.
2. Anthropogenic Sources of Mercury Emissions
Since the beginning of the industrial age, human activities have increased the amount of mercury releases to the environment. Today in the United States, the combustion of coal at coal-fired power plants represents the largest source category of mercury emissions at approximately 43%. The second largest category after coal-fired power plants is electric arc furnaces at 10%.
This Commonwealth has 36 coal-fired power plants with 78 EGUs that represent approximately 20,000 megawatts of capacity. These units accounted for approximately 78% of the more than 5 tons of mercury emitted into the air from all contamination sources in this Commonwealth, ranking this Commonwealth second only to Texas in terms of total mercury emissions and third behind Texas and Ohio, respectively, for EGU-specific mercury emissions in 2003. The Commonwealth's next largest source of mercury emissions is the stone/clay/glass category, which accounts for almost 9% of the total.
The primary reason that coal-fired power plants represent such a large percentage of mercury emissions in the United States and this Commonwealth is because this source category is unregulated for this type of emissions. While both the National and Pennsylvania figures show that coal-fired power plants emit a disproportionate amount of mercury, mercury emissions from coal-fired power plants in this Commonwealth are disproportionate to the National figure. Therefore, the Board believes that it is important to ensure that uncontrolled mercury emissions from the EGU source category are regulated as intended by Congress under the CAA.
3. The Mercury Cycle in the Environment
Mercury cycles throughout the environment are a consequence of both natural and human activities. The annual global cycling of mercury in the earth's atmosphere amounts to about 5,000 tons. It is estimated that 4,000 tons are the consequence of anthropogenic activities. The United States is responsible for 3% of global anthropogenic emissions. Mercury in the air eventually settles into water or onto land where it can be washed into water. Once deposited, certain microorganisms can change it into methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish. Methylmercury builds up more in some types of fish and shellfish than others. The levels of methylmercury in fish and shellfish depend on what they eat, how long they live and how high they are in the food chain. Fish and shellfish are the main sources of methylmercury exposure to humans. Because the developing fetus may be the most sensitive to the effects from methylmercury, women of childbearing age are regarded as the population of greatest interest.
4. Mercury Deposition in this Commonwealth's Environment
The mercury in the flue gas of EGUs can be characterized as being in two forms: ionic (oxidized) or elemental. The ability of an air pollution control system to capture the mercury is dependent, in part, on the species of the mercury in the flue gas. When the coal is burned in an electric utility boiler, the resulting high combustion temperatures vaporize the mercury in the coal to form gaseous elemental mercury (Hg0). Subsequent cooling of the combustion gases and interaction of the gaseous Hg0 with other combustion products results in a portion of the Hg being converted to gaseous ionic or oxidized forms of mercury (Hg+2) and particle bound mercury (Hgp). The lifetime of elemental mercury (Hg0) in the atmosphere is estimated to be up to 1 year, while ionic forms have a lifetime of only a few days because of particulate settling and solubility. Hg0 can be transported over transcontinental distances, whereas Hg+2 and Hgp forms are deposited near their source. Coal-fired power plants that burn bituminous coal emit oxidized forms of mercury. In this Commonwealth, 85% of the coal burned by coal-fired power plants is bituminous, with the remainder waste coal. In this Commonwealth, on a Statewide average, the exhaust gas split of the three forms of mercury is as follows: 5.93% Hgp; 59.99% Hg+2; and 34.08% Hg0. The percentage of Hg+2 emitted in this Commonwealth is higher than the National average. Consequently, coal-fired power plants in this Commonwealth are more likely to cause local deposition.
On April 27, 2005, preliminary results from the EPA-funded ''Steubenville Mercury Deposition Source Apportionment Study'' were released. This study found that nearly 70% of the mercury in rain collected at an Ohio River Valley monitoring site originated from nearby coal-burning industrial plants. See ''Sources of Mercury Wet Deposition in Eastern Ohio, USA,'' Keeler, et al. Environ. SciTechol 40(19)5874-5881 (2006). Also, according to the Goddard Earth Observing System-Chem modeling and Community Multi-scale Air Quality modeling results for 2001, the mercury deposition attributable to United States EGUs in the eastern portion of the country is generally 1--5 µg m-2 range. However, in the eastern United States, there is a large area in the Ohio River Valley with EGU attributable mercury depositions in the 5-10 µg m-2 range and a much smaller area in the 10-15 µg m-2 range. United States EGUs attributable mercury depositions over 20 µg m-2 are found in parts of this Commonwealth. It is in this Commonwealth where the maximum percentage of utility attributable deposition of 71% compared to total deposition from all sources occurs. See ''Mercury Deposition Modeling with the Community Multi-scale Air Quality (CMAQ) Model for the Clean Air Mercury Rule (CAMR),'' Thomas N. Braverman, United States Environmental Protection Agency, Office of Air Quality Planning and Standards, Mail Code C439-01, Research Triangle Park, NC 27711, Poster Session, 8th International Conference on Mercury as a Global Pollutant, June 2006. These and other studies confirm the Board's conclusion that the mercury speciation trends for this Commonwealth tend to favor the likelihood of higher local mercury deposition than that for the National average.
5. Mercury in this Commonwealth's Environment
Accumulation of mercury in aquatic ecosystems has resulted in 45 states, including this Commonwealth, issuing fish consumption advisories. The Commonwealth has fish consumption advisories for mercury in approximately 80 waterways across this Commonwealth, which include the Delaware, Ohio, Potomac and Susquehanna River Basins and the Lake Erie Basin. Mercury fish advisories account for 60% of the fish consumption advisories throughout this Commonwealth.
The Department has reviewed the mercury tissue concentration of fish in water bodies in this Commonwealth from 1999 to 2004. The highest fish concentration of mercury was 1.564 ppm in walleye found at Lake Wallenpaupack. The lowest fish concentration of mercury was 0.036 ppm found in brown trout in the Delaware River near State Route 191. Of the approximately 187 sampling sites, 100 sites found fish tissue concentrations of 0.32 ppm or more which has an EPA risk-based consumption limit of no more than 2 meals per month.
The Department has mapped the location of the active, and in some cases, inactive power plants in this Commonwealth together with the mercury concentration found in fish. For example, the Department has identified 4 sampling sites with fish tissue concentrations in the 0.30 to 0.89 ppm range within a 50-mile radius of the Shawville power plant in Clearfield County. This data suggests a correlation between higher mercury fish concentrations and power plants within a 50-mile radius from the sampling sites. Also, this data lends strong support to the Department's concern that coal-fired power plants that burn bituminous coal emit ionic forms of mercury, which are deposited near their source. As a result, the Board has concluded that mercury contamination is ubiquitous across this Commonwealth and should be reduced.
6. Health Effects of Mercury
Mercury is a dangerous reproductive and neurological toxicant. It can affect the brain, spinal cord, kidneys and liver. High exposure levels to mercury can affect the ability to feel, see and taste and has the potential to limit mobility. A study by the National Academy of Sciences (NAS) concluded that human exposure to methylmercury from eating contaminated fish and seafood is associated with adverse neurological and developmental health effects. Women of childbearing age and pregnant women are of special concern in terms of methylmercury exposure. Methylmercury exposure prior to pregnancy can actually place the developing fetus at risk because methylmercury persists in body tissue and is only slowly excreted from the body. Furthermore, according to the NAS, chronic low-dose prenatal methylmercury exposure has been associated with poor performance on neurobehavioral tests in children, including tests that measure attention, visual spatial ability, verbal memory, language ability, fine motor skills and intelligence. Adults can be affected by high mercury exposures as well, with effects on the nervous system and impaired vision and hearing.
In the EPA's Mercury Study Report to Congress (1997), the EPA estimated that 7% of women of childbearing age would have blood mercury concentrations greater than those equivalent to the Reference Dose (RfD). The estimate of 7% of women of childbearing age above the RfD was based on patterns of fish and shellfish consumption and methylmercury concentrations present in fish and shellfish. Blood mercury analyses in the 1999-2000 National Health and Nutrition Examination Survey (NHANES) for 16- to 49-year old women showed that approximately 8% of women in the survey had blood mercury concentrations greater than 5.8 µg/L (which is a blood mercury level equivalent to the current RfD). Based on this prevalence for the overall population of women of reproductive age in the United States and the number of births each year in the United States, it is estimated that more than 300,000 newborns each year may have increased risk of learning disabilities associated with in utero exposure to methylmercury.
To determine levels of total blood Hg in childbearing-aged women and in children 1 to 5 years of age in the United States, the CDC's NHANES began measuring blood Hg levels in these populations in 1999. The NHANES is a continuous survey of the health and nutritional status of the civilian, noninstitutionalized U.S. population; data are released and reported in 2-year cycles. NHANES results for 1999--2002 confirmed that blood mercury levels in young children and women of childbearing age usually are below levels of concern. However, approximately 6% of childbearing-aged women had levels at or above an RfD.
One area in which the toxicokinetic data have been consistent is the finding that methylmercury is actively transferred to the fetus across the placenta by means of neutral amino acid carriers during gestation. Although maternal and cord blood mercury concentration is highly correlated, cord-blood mercury is consistently higher than the corresponding maternal concentration with an average ratio of about 1.7. Consequently, for biomonitoring of adult women's blood methylmercury commonly used as a surrogate for potential fetal exposure, the corresponding fetal level will be, on average, 70% higher than maternal blood and up to three times higher at the 95th percentile. The maternal body burden of methylmercury tends to decrease during gestation, consistent with hemodilution and a transfer of a portion of the maternal body burden to the fetus.
Recent separate studies by Stern, et al., (2006), Trasande et al., (2005) and Mahaffey, et al., (2004) suggest that even the EPA-established RfD is too high. According to Trasande, there is no evidence to date validating the existence of a threshold blood mercury concentration below which adverse effects on cognition are not seen. See Leonardo Trasande, et al., ''Public Health and Economic Consequences of Methylmercury Toxicity to the Developing Brain,'' Environmental Health Perspectives, 113:590-596 (2005). Stern in his 2006 presentation at the 8th International Conference on Mercury as a Global Pollutant entitled ''An Estimate of the Population Variability in the Relationship Between Cord Blood Mercury and Maternal Methylmercury Intake'' found that the EPA RfD should be reduced by 33%. See also Stern, et al., ''An Assessment of the Cord Blood Maternal Blood Methylmercury Ratio: Implications for Risk Assessment,'' Environmental Health Perspectives 111:1465--1470 (2003). In January 2004, an EPA researcher estimated that at least 7.8% (and possibly as many as 15.7%) of women of childbearing age had blood mercury levels high enough that approximately 630,000 newborns may be at risk from the adverse effects of mercury. Kathryn R. Mahaffey, Ph.D., ''Methylmercury: Epidemiology Update'' (January 26, 2004).
Additionally, Congress declared that the HAPs listed under section 112(b) of the CAA pose a significant threat to public health; the risk of adverse health effects related to these emissions were significant; and HAPs may cause significant environmental damage.
Because of these and other studies, the Board has determined that methylmercury is a public health concern for the developing fetus, women of childbearing age, young children and adults. Moreover, the Board has determined that a reduction in the amount of mercury and methylmercury in the environment would improve local ecosystems and public health, especially the health of developing fetuses, young children and women of childbearing age.
7. Cost Benefit Studies Related to Mercury Emissions
The Northeast States for Coordinated Air Use Management (NESCAUM) sponsored a report analyzing the cost savings and public health benefits of controlling mercury emissions from power plants. NESCAUM, Economic Valuation of Human Health Benefits of Controlling Mercury Emissions from U.S. Coal-fired Power Plants (February 2005) (Harvard Study). The Harvard Study reveals that the EPA miscalculated the ''nature of the risk involved'' by underestimating the public health benefits of reducing mercury. Specifically, the Harvard Study indicates that the public benefit of reducing power plant mercury emissions to 15 tpy ranges from $119 million annually (if only persistent IQ deficits from fetal exposures to methylmercury are counted) to as much as $5.2 billion annually (if IQ deficits, cardiovascular effects and premature mortality are all counted).
The May 2005 edition of Environmental Health Perspectives indicates that the EPA underestimated the health benefits to be gained from reducing mercury. In one study, scientists from the Mount Sinai School of Medicine examined National blood mercury prevalence data from the CDC and found that between 316,588 and 637,233 children each year have cord blood mercury levels greater than 5.8 micrograms per liter--the level associated with loss of IQ. See Leonardo Trasande, et al., ''Public Health and Economic Consequences of Methylmercury Toxicity to the Developing Brain,'' 113 Environmental Health Perspectives, No. 5 (May 2005). They estimated that the resulting loss of intelligence and diminished economic activity amounted to $8.7 billion annually, with $1.3 billion each year being directly attributable to mercury emissions from power plants. The scientists further caution that these costs will recur each year with each new birth cohort as long as mercury emissions are not controlled.
Trasande and his colleagues have further concluded that their calculations on economic cost may, in fact, be an underestimate. See ''Mental retardation and prenatal methylmercury toxicity.'' Am. J. Ind. Med. 2006 Mar; 49(3):153-8. Downward shifts in IQ resulting from prenatal exposure to methylmercury of anthropogenic origin are associated with 1,566 excess cases of mental retardation annually (range: 376--14,293). This represents 3.2% of mental retardation cases in the United States (range: 0.8%--29.2%). The mental retardation costs associated with decreases in IQ in these children amount to $2.0 billion/year (range: $0.5--$17.9 billion). Mercury from American power plants accounts for 231 of the excess mental retardation cases/year (range: 28--2,109), or 0.5% (range: 0.06%--4.3%) of all mental retardation. These cases cost $289 million (range: $35 million--$2.6 billion). Therefore, Trasande concludes that toxic injury to the fetal brain caused by mercury from coal-fired power plants exacts a significant human and economic toll on American children. These conclusions have been peer-reviewed.
It should also be noted, as previously discussed, under the 1990 amendments to the CAA, Congress ended the debate regarding the development of risk analyses for HAPs. Congress concluded that a technology-based approach was appropriate because routine and episodic releases of HAPs posed a significant threat to public health; the risk of adverse health effects related to these emissions were significant; and HAPs may cause significant environmental damage. As a result, HAP emissions must be regulated to the maximum extent possible. Therefore, the Board concludes that the benefits of regulating mercury emissions from coal-fired power plants in this Commonwealth outweigh the costs associated with that regulation.
8. Federal Analysis Related to the CAMR
On February 3, 2005, the EPA's Office of Inspector General (OIG) published an Evaluation Report: ''Additional Analyses of Mercury Emissions Needed before EPA Finalizes Rules for Coal-Fired Electric Utilities.'' The EPA's OIG found that the EPA's cap-and-trade proposal failed to adequately address the potential for hotspots of mercury pollution. The OIG also found evidence that, instead of basing its proposed MACT standard on an unbiased determination under section 112(d) of the CAA of what mercury emission rates the top performing units were achieving, EPA staff followed orders from EPA senior management and simply set the MACT standard at a rate that would result in National emissions of 34 tons annually. Finally, the OIG found that the EPA's rule development process did not comply with certain Agency and Executive Order requirements, including fully analyzing the costs/benefits of regulatory alternatives and fully assessing the rule's impact on children's health. The OIG recommended that the EPA conduct additional analyses of mercury emissions data, strengthen its cap-and-trade proposal, assess the costs/benefits of regulatory alternatives to its proposal and fully explore potential impacts to children's health.
In February 2005, the United States Government Accountability Office (GAO) issued a report to Congressional requesters entitled ''Clean Air Act: Observations on EPA's Cost-Benefit Analysis of Its Mercury Control Options.'' The GAO concluded that the EPA's economic analysis of its proposed mercury control options had four major shortcomings: it failed to document some of its analysis; it failed to follow Office of Management and Budget guidance; it did not estimate the value of health benefits that would result from decreased mercury emissions; and it failed to analyze some of the key uncertainties underlying its cost/benefit estimates. The GAO concluded that, as a result of these shortcomings, the EPA's cost/benefit estimates are not comparable and are of limited use for assessing the economic trade-offs of the different options for controlling mercury.
On April 15, 2005, the Congressional Research Service developed a report entitled ''Mercury Emissions from Electric Power Plants: An Analysis of EPA's Cap-and-Trade Regulations.'' Among other things, this report found that the CAMR would allow utilities to delay full compliance with the 70% reduction until well beyond 2018, as they use up banked allowances rather than install further controls. The EPA's analysis projects actual emissions to be 24.3 tons as late as 2020 (less than a 50% reduction compared to baseline 1999 emissions). The report further found that it appears that full compliance with the 70% reduction might be delayed until 2030.
In a May 15, 2006, report entitled ''Monitoring Needed to Assess Impact of EPA's Clean Air Mercury Rule on Potential Hotspots,'' the EPA OIG found several uncertainties associated with key variables in the analysis could affect the accuracy of the EPA's conclusion that the CAMR will not result in ''utility-attributable'' hotspots. They noted gaps in available data and science for mercury emissions estimates, limitations with the model used for predicting mercury deposition, uncertainty over how mercury reacts in the atmosphere and uncertainty over how mercury changes to a more toxic form in water bodies.
The Board finds that there were serious procedural and analytical flaws related to the promulgation of the EPA's CAMR.
9. Legal Analysis Related to the Control of HAPs under the CAA and the APCA
The Department has determined that the EPA does not have the legal authority to develop a regulatory scheme for a HAP, like mercury, under section 111 of the CAA. The Congressional intent regarding the regulation of mercury is clear and unambiguous--it must be regulated under section 112 of the CAA. Mercury is explicitly identified as an HAP under section 112(b) of the CAA. For sources other than coal-fired units, the EPA must list source categories under section 112(c) of the CAA and then set emission standards for those categories under section 112(d) of the CAA. While the statutory scheme for regulating mercury from coal-fired units is under section 112(n) of the CAA, the Congressional intent is the same--mercury emissions from these units must be regulated under the Section 112 MACT approach. See Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984) (where if the intent of Congress is clear, that is the end of the matter; for the court, as well as the agency, must give effect to the unambiguously expressed intent of Congress.)
The EPA's proposed ''cap-and-trade'' program is an unreasonable interpretation of its statutory authority under sections 111 and 112 of the CAA. The fact that Congress chose to list specific HAPs under section 112 of the CAA indicated that Congress believed that these pollutants required more stringent measures than those permitted under section 111 of the CAA. Moreover, regulation under section 112 of the CAA has been historically and consistently interpreted as requiring HAPs to be controlled through installation and operation of MACT. A cap-and-trade approach under this section was never contemplated as a control technology. As a result, the EPA is now acting contrary to Congressional intent by attempting to regulate mercury HAP sources under a less stringent standard than the framers of the CAA desired.
The APCA also contains specific provisions applicable to the regulation of HAPs under section 112 of the CAA. Section 6.6(a) of the APCA (35 P. S. § 4006.6(a)) provides that ''the regulations establishing performance or emission standards promulgated under section 112 of the [CAA] are incorporated by reference into the Department's permitting program.'' Section 6.6(a) of the APCA further provides that the ''Environmental Quality Board may not establish a more stringent performance or emission standard for hazardous air pollutant emissions from existing sources, except as provided in subsection (d) [regarding health risk-based emission standards].'' This ''no more stringent than'' provision applies to performance standards (MACT) or requirements adopted under section 112 of the CAA.
As previously noted, the EPA revised its December 2000 ''appropriate and necessary'' regulatory finding for the regulation of mercury emissions from coal- and oil-fired EGUs as HAPs and delisted EGUs, which were included on a list of source categories under section 112(c) of the CAA. Section 6.6(a) of the APCA provides that the Board may establish emission standards for source categories which are not included on the list of source categories established under section 112(c) of the CAA. Because of the EPA's ''delisting'' action in December 2000, the limitations in section 6.6(a) of the APCA are not applicable to performance standards and other measures that would be adopted to implement the Section 111 standards for new and existing sources.
The Board had determined that it has the legal authority to promulgate a regulation under the APCA to control mercury emissions from coal-fired EGUs within this Commonwealth.
10. Petition for Rulemaking Process
On August 9, 2004, Citizens for Pennsylvania's Future, PennEnvironment, Pennsylvania Federation of Sportsmen's Clubs, Pennsylvania NOW, Pennsylvania State Building and Construction Trades Council, Pennsylvania Trout, Planned Parenthood Pennsylvania Advocates, Sierra Club Pennsylvania Chapter, Women's Law Project and WomenVote PA (petitioners) filed a petition for rulemaking under Chapter 23 (relating to Environmental Quality Board policy for processing petitions--statement of policy) requesting that the Board adopt regulations to reduce mercury emissions from electric utilities in this Commonwealth. Since the original filing of the petition, an additional 39 organizations declared their intent to be copetitioners. The petitioners seek to protect human health and the environment through the regulation of mercury emissions from coal-fired power plants in this Commonwealth. They requested that the Department exercise its statutory authority under the APCA and develop a regulatory program to reduce the mercury emissions from electric utilities for consideration by the Board. The petitioners submitted suggested regulatory language adapted from a January 5, 2004, New Jersey Department of Environmental Protection (NJDEP) proposal to reduce mercury emissions from coal-fired boilers.
On May 18, 2005, the Department finalized its response to the petitioners' petition for rulemaking and set forth its rationale as to why neither the NJDEP regulation nor the EPA's CAMR was in the best interest of this Commonwealth. The New Jersey regulatory language has one emission standard for both new and existing sources. The Department believes there should be separate emission standards for new and existing coal-fired boilers. Moreover, New Jersey has a limited number of coal-fired utility units which are not representative of the significantly varied boiler types in this Commonwealth.
The Department also does not believe that the EPA's Section 111 approach to mercury control for the electric generating sector is best for this Commonwealth. The Department strongly opposes a cap-and-trade approach under the CAMR for the regulation of mercury emissions from the utility sector for a number of reasons. First, the Department believes that the EPA does not have the legal authority to regulate an HAP like mercury under the less stringent provisions of section 111 of the CAA, as opposed to the more stringent provisions under section 112 of the CAA. Second, the Department believes this approach will significantly delay the control of mercury emissions from the utility sector and will create ''hot spots'' of mercury exposure that could be very detrimental to humans and wildlife. Third, the Department believes that the CAMR, since it is not a fuel-neutral regulation, requires greater reductions from coal-fired units that burn bituminous coal from states like this Commonwealth. Consequently, the Department recommended that a comprehensive approach to mercury control should be considered and recommended the development of a fuel-neutral regulatory approach to mercury emissions control.
On August 16, 2005, the Board accepted the Department's recommendation to move forward with a Pennsylvania-specific mercury rulemaking with an expanded public involvement process. The list of stakeholders to be included in the public involvement process was expanded to include the Pennsylvania Chamber of Business and Industry, Pennsylvania Chemical Industry Council, Associated Petroleum Industries of Pennsylvania, Pennsylvania Manufacturers Association, Industrial Energy Users of Pennsylvania, Electric Power Generation Association, Pennsylvania Coal Association, United Mine Workers of America, Air Quality Technical Advisory Committee (AQTAC), Citizens Advisory Council, the petitioners and other representatives of the potentially regulated community.
The Department established a Mercury Rule Workgroup (Workgroup) as part of the expanded public involvement process for a Pennsylvania-specific mercury rule. The intent of the Workgroup was not to reach consensus regarding the regulation of mercury emissions in this Commonwealth, but to develop information to assist the Department in the development of a mercury rule and enhance the public participation regarding the drafting of this final-form rulemaking. The first Workgroup meeting was held on October 14, 2005. During the first meeting, presentations included Workgroup objectives, an overview of mercury, its fate and transport and other State regulations. The second meeting of the Workgroup was held on October 28, 2005. The second meeting focused on the health impacts of mercury. The third meeting of the Workgroup was held on November 18, 2005. Speakers at this meeting discussed the health impacts of mercury and methods of controlling mercury emissions from coal-fired power plants. The last Workgroup meeting was held on November 30, 2005. The last meeting focused on additional health impacts regarding mercury and Workgroup members and others discussed their organizations' proposals for the control of mercury.
On February 22, 2006, the Department presented concepts of its proposed rulemaking at a joint meeting of the Workgroup, the AQTAC and the Citizens Advisory Council. Additionally, on March 30, 2006, the AQTAC recommended that the Board consider the proposed rulemaking at its May 17, 2006, meeting.
On May 17, 2006, the Board heard a Department presentation concerning the proposed mercury rulemaking. During discussions on the proposed rulemaking, Board members from the Citizen's Advisory Council requested that the Department prepare a Decision Document. Following discussion, the Board approved the proposed rulemaking for public comment. The Board also requested a Decision Document to complement other documentation prepared for the final-form mercury rulemaking. The Board noted that this document should set forth the Department's justification, rationale and supporting information for any final-form rulemaking. The Decision Document is available for public inspection at the Department's website: www.depweb.state.pa.us. The Decision Document includes a compilation and summary of the data, models, studies and evidence considered and used to support the decision making; the legal and regulatory history and rationale for the rulemaking; and an evaluation of arguments and information presented by those in favor and opposed to the rulemaking and an explanation of the decision trail and intent of the final-form rulemaking.
The proposed rulemaking was published at 36 Pa.B. 3185 (June 24, 2006) for a 60-day comment period.
The Board held public meetings on the proposed regulation on July 25, 2006, at the Department's Southwest Regional Office in Pittsburgh; on July 26, 2006, at the Rachel Carson State Office Building in Harrisburg; and on July 27, 2006, at the Department's Southeast Regional Office in Norristown.
On September 27, 2006, the Department requested that the AQTAC take action on this final-form rulemaking. The AQTAC approved this final-form rulemaking for consideration by the Board at its October 17, 2006, meeting.
11. Public Health and Environmental Improvements Regarding a Pennsylvania-Specific Mercury Emissions Reduction Rule
The Department has reviewed several studies and reports of fish consumption by the general population and by sport anglers to answer the question of how these anglers and their families might be at risk of consuming mercury contaminants at levels greater than health-based limits in the fish they caught. Because Statewide data is limited, the Department reviewed National surveys to evaluate fish consumption. These studies are extraordinarily useful to summarize data on human behaviors and characteristics, which affect exposure to environmental contaminants, like mercury. For example, the EPA's ''Exposure Factors Handbook'' was consulted to obtain data on standard factors needed to calculate human exposure to mercury from fish intake. For all fish the recommended values are 6.0 grams per day (g/d) for freshwater/estuarine fish, 14.1 g/d for marine fish, and 20.1 g/d for all fish. The recommended mean and 95th percentile values for recreational freshwater anglers are 8 g/d and 25 g/d, respectively.
The Fish and Boat Commission determined that in 2005 approximately 800,000 anglers fished in waters in this Commonwealth. Studies of sport fish consumption by angler cohorts in Michigan provide a thorough evaluation of consumers of sport fish. The studies of Michigan anglers provide data for total amounts of fish and self-caught fish consumed by various subgroups of the cohort. See, for example, West, ''1991-1992. Michigan sport anglers fish consumption study,'' University of Michigan School of Natural Resources for the Michigan Department of Natural Resources, Technical Report No. 6, 1993. This group also consumes much more fish than the general population, with mean and 95th percentile rates as high as 61.3 and 123.9 g/d (99 and 199 meals/year), respectively. Particularly relevant for describing at-risk populations is the information regarding females (ages not specified), with mean and 95th percentile of total fish consumption reported to be 42.3 and 85.7 g/d (68 and 138 meals/year), respectively.
Hudson River Sloop Clearwater, Inc. conducted a survey of adherence to fish consumption health advisories among Hudson River anglers. See ''Hudson River Angler Survey,'' Hudson River Sloop Clearwater, Inc. (1993). Approximately 94% of Hispanic Americans were likely to eat their catch, while 77% of African Americans and 47% of Caucasian Americans intended to eat their catch. Of those who eat their catch, 87% were likely to share their meal with others (including women of childbearing age and children under 15 years of age).
In 2000, a study was published on behalf of the Fish and Boat Commission to determine levels of stocked trout consumption among anglers as well as their awareness and attitudes towards consumption advisories. See ''Levels of Trout Consumption and Attitudes Toward Consumption Advisories Among Pennsylvania Trout Anglers,'' Responsive Management, 2000, conducted for the Pennsylvania Fish and Boat Commission. Of those who were aware of trout consumption advisories, 78% stated that they followed them but only 48% said that the advisory impacted their consumption decisions regarding stocked trout.
The Department's review of fish consumption literature provides strong support that sport anglers in this Commonwealth may consume amounts of sport-caught fish that could allow them and their families to exceed health-based limits for mercury contaminants in their fish. The literature regarding anglers' consumption of their catch strongly suggests that a subset of these anglers have meal frequencies that put them well above the recommended rates for even fairly low levels of contamination. Furthermore, a review of the relevant studies suggests that there is a strong environmental justice component regarding this public health issue. Consumption rates were higher among minorities, people with low income and people residing in smaller communities. As a result, the Department can say with a high level of confidence that it is possible for anglers and their families to consume enough sport fish to put themselves and their families at risk from mercury contamination from their fish.
A multiagency State of Florida study launched in 1994 compared mercury levels in the Everglades before and after pollution controls were installed at municipal and medical waste incinerators in South Florida. See ''Everglades Consolidated Report,'' The South Florida Water Management District and the Florida Department of Environmental Protection. Since the 1980s, mercury emissions from waste incinerators close to the Everglades have dropped nearly 99%. Over the last 10 years, scientists documented a 70% decline in mercury in bird feathers and a 60% decrease in fish tissue. While this study focused on waste incinerators and not bituminous coal-fired power plants, it is important to note that both source categories emit comparable amounts of ionic mercury, which deposits locally. As a result, the conclusions in the multiagency Florida study are applicable to this Commonwealth.
The mercury concentration in fish was investigated in a region of Massachusetts predicted to have regionally high atmospheric deposition of mercury during 1999 to 2004. See ''Massachusetts Fish Tissue Mercury Studies: Long Term Monitoring Results 1999-2004,'' Massachusetts Department of Environmental Protection, 2006. In eight of the nine water bodies in northeastern Massachusetts, significant decreases in mercury in yellow perch were observed with a range of 26.0% to 61.9%. The mean decrease over all lakes was 32.4%. Five of the remaining eight lakes around the rest of the state also had statistically significant, but not as large, decreases in yellow perch mercury levels ranging from 20.1% to 28.0% with an overall mean decrease of 15.4%.
Large mouth bass mercury concentrations followed a similar pattern with 11 of 17 lakes throughout the state decreasing in tissue mercury concentrations. Eleven of the lakes sampled were in northeastern Massachusetts and mercury levels in large mouth bass from seven of those decreased significantly, ranging from 16.0% to 55.2% with a mean decrease of 24.8%. Four of the remaining six lakes located around the rest of the state also had statistically significant but smaller decreases in large mouth bass mercury concentrations. The range of these decreases was 15.9% to 36.4% with a mean decrease of 19.0%. These reductions were achieved primarily through the imposition of stringent mercury emissions controls on municipal solid waste incinerators and medical waste incinerators, as well as reductions from other regional sources. In both studies, the emission reductions, which are predominantly in the form of ionic mercury from local incinerators, resulted in significant reductions in mercury levels in fish. As with the Florida study, while this study focused on waste incinerators, and not bituminous coal-fired power plants, it is important to note that both of source categories emit comparable amounts of ionic mercury, which deposits locally. As a result, the conclusions in this Massachusetts study are applicable to this Commonwealth.
Other studies confirm the results of the Florida and Massachusetts studies where the response of mercury deposition rates to emission reductions close to anthropogenic sources is expected to be much more rapid than that at remote locations, largely because near-field mercury deposition is probably dominated by local Hg+2 emissions. These studies find good historical evidence from lake-sediment records for rapid and large (30%--50%) declines in mercury deposition from urban areas in the United States and Europe. Moreover, these declines occurred over the last 1 to 3 decades and correspond with known reductions in local and regional mercury emissions for the same areas. See Munthe, J., et al., ''Input-output of Hg in forested catchments in Europe and North America.'' RMZ-Materials and Geoenvironment, 51:1243--1246, (2004). See also Engstrom, D.R., and Swain, E.B. 1997. ''Recent declines in atmospheric mercury deposition in the upper Midwest.'' Environ. Sci. Technol. 312: 60--967. See Kamman, N.C., and Engstrom, D.R. 2002. ''Historical and present fluxes of mercury to Vermont and New Hampshire lakes inferred from 210Pb dated sediment cores.'' Atmos. Environ. 36: 599--1609.
The literature review conducted by the Department confirms that mercury reduction approaches translate into a significant drop in mercury concentrations found in fish and other fauna. These illustrate the point that despite the fact that there are global mercury transportation issues, local emission reduction efforts are very significant to the local air quality, human exposure and environmental impacts. Continued improvements to the ecosystem are expected in the long-term as these reductions work their way through the food chain. Consequently, the Board has found reductions in mercury emissions do translate into real, measurable improvements in public health and the environment in this Commonwealth.
12. Improvements Regarding the Tourism Industry in this Commonwealth
As previously noted, the Fish and Boat Commission determined that in 2005 approximately 800,000 anglers fished in waters in this Commonwealth. Fish licensing sales in this Commonwealth amounted to $18.5 million in 2005. According to the Erie Regional and Growth Partnership, residents of this Commonwealth 16 years of age and older spent $400 million on fishing in this Commonwealth in 2001. The average angler spent $458 in 2001 on fishing. These direct expenditures created $1.2 billion in Pennsylvania economic output. Also as noted previously, this Commonwealth has fish consumption advisories for mercury in approximately 80 waterways across this Commonwealth, 60% of which are related to mercury fish consumption advisories.
Resources for the Future conducted a study on mercury contamination of the Chesapeake Bay entitled ''The Benefits and Costs of Fish Consumption Advisories for Mercury,'' October 2002. Applying an estimate of the percentage of consumer surplus lost due to an advisory from the literature to consumer surplus estimates for a fishing day in the Chesapeake Bay, they estimate an annual consumer surplus loss over all Maryland saltwater fishing days of $8.83 million (in $2,000). For the commercial striped bass fishery, they estimate a very simple model of supply and demand that predicts equilibrium price and quantity with reasonable accuracy. Using parameter estimates from this model, they estimate annual consumer and producer surplus losses of $215,800 and $304,500, respectively, under commercial consumption advice, for a total annual surplus loss of $520,300.
Furthermore, based on their mortality estimate, the Resources for the Future report estimates annual health benefits from an advisory to be approximately $14 million. They conclude the value of further information for this mercury mortality relationship is quite high, as it suggests that significant health benefits may accrue at lower mercury levels than has been suggested by the research focusing on neurological development effects from fetal exposure, the health endpoint that has been the focus of policy discussion to date.
As a result, the Commonwealth has a significant economic interest in fresh water fishing as an economic driver. Therefore, the Board finds that any improvement, or prevention of loss, to fish activities in this Commonwealth through implementation of this final-form mercury rulemaking could have a positive impact to this important industry.
13. Mercury Reduction Technologies
Coal-fired power plants that burn subbituminous coal emit elemental mercury, which is very difficult to capture with conventional air pollution control devices like wet flue gas desulfurization (WFGD) for sulfur dioxide (SO2) control and selective catalytic reduction (SCR) for nitrogen oxides (NOx) control. Moreover, coal-fired power plants that burn subbituminous coal emit Hgo, which can be transported over transcontinental distances. Coal-fired power plants that burn bituminous coal emit oxidized forms of mercury, which are easier to capture using WFGD and SCR. Coal-fired power plants that burn bituminous coal emit oxidized forms of mercury, which are deposited near their source. For example, EGUs that burn 100% subbituminous coal and control emissions with a WFGD and SCR can expect to capture approximately 16% of mercury emissions. In contrast, EGUs that burn 100% bituminous coal and control emissions with WFGD and SCR can expect to capture approximately 90% of mercury emissions. In this Commonwealth, 85% of coal the burned by coal-fired power plants is bituminous, with the remainder waste coal.
This final-form rulemaking is designed, in part, to take advantage of the cobenefit reductions that will occur under the Clean Air Interstate Rule (CAIR), published at 70 FR 72268 (December 2, 2005), designed to reduce SO2 and NOx emissions from EGUs.
Owners and operators of facilities in this Commonwealth provided mercury emissions data and mercury coal content data to the Department in December 2005 in response to an information request. Using this data, the mercury removal efficiencies from the facilities that provided mercury emissions data were determined. The analysis of this data show that EGUs controlled with cold side-electrostatic precipitator (ESP) and WFGD reduce mercury by 80% and EGUs controlled with cold side--ESP, WFGD and SCR reduce mercury by over 90%. While these control devices were not specifically designed to remove mercury, it is possible to modify their operation to increase mercury collection without degrading other emission control or operational aspects. Testing has shown that increasing the rate of slurry recirculation in scrubbers will increase mercury removal. New additives, injected into the scrubber slurry, may also increase mercury removal.
Powdered activated carbon injection (ACI) controls mercury emissions by adsorption onto its surface. Carbon is injected into flue gas and controlled downstream by a particulate collector along with adsorbed mercury. Properties of the activated carbon are selected to maximize mercury control. It is much more effective adsorbing ionized mercury than elemental mercury vapor. Activated carbon treated with a halide, usually bromine, can also be used. It generally provides additional mercury control over other activated carbon for the same injection rate into the flue gas. The Compact Hybrid Particulate Collector (COHPAC) system requires installation of a final fabric filter in addition to existing control equipment. Tested mercury removal rates for various ACI rates from the EPA paper ''Control of Mercury Emissions from Coal Fired Electric Utility Boilers: An Update'' issued February 18, 2005, shows removal rates of 90% for ACI with cold side--ESP, ACI-COHPAC and brominated-ACI (B-ACI) with cold side-ESP.
The Institute of Clean Air Companies found that air pollution control vendors are reporting booking new contracts for mercury control equipment for more than a dozen power plant boilers. The contracts for commercial systems are attributed to Federal and state regulations, including new source permit requirements and consent decrees, which specify high levels of mercury capture.
A Congressional Research Service Report, April 15, 2005, found that the EPA's own Office of Research and Development (ORD) in a white paper posted on the EPA's website on March 2, 2004, appears to conclude that technology is more available and more effective than is maintained in the EPA's CAMR rulemaking. The ORD found that fabric filters, a relatively simple technology that is currently installed on more than 12% of power plants, achieve a 90% reduction in mercury emissions at bituminous coal plants and a 72% reduction at subbituminous plants. The addition of a scrubber increased the emission reduction to 98% at bituminous plants, according to the ORD. The white paper further stated that, by 2010, ACI with a fabric filter ''has the potential to achieve 90% Hg reduction'' on any rank of coal, and could be installed within 1 to 2 years of signing a contract to do so. Since the white paper was written, there have been reports that a European firm, Donau Carbon, has begun offering commercial guarantees for mercury removal from coal-fired power plants using ACI technology.
Accordingly, the Board finds that mercury reduction technologies and other technologies are commercially available and cost effective to the owners and operators of EGUs to assist them in reducing mercury emissions from EGUs.
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