[Federal Register Volume 65, Number 245 (Wednesday, December 20, 2000)]
[Notices]
[Pages 79825-79831]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-32395]


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ENVIRONMENTAL PROTECTION AGENCY

[AD-FRL-6919-6]
2060-ZA10


Regulatory Finding on the Emissions of Hazardous Air Pollutants 
From Electric Utility Steam Generating Units

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of regulatory finding.

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SUMMARY: This notice presents EPA's finding required by section 
112(n)(1)(A) of the Clean Air Act (CAA) as to whether regulation of 
emissions of hazardous air pollutants (HAP) from fossil fuel-fired 
electric utility steam generating units (as defined in section 
112(a)(8) of the CAA) is appropriate and necessary. This finding is 
based on the results of EPA's February 1998 ``Study

[[Page 79826]]

of Hazardous Air Pollutant Emissions from Electric Utility Steam 
Generating Units--Final Report to Congress' (utility RTC), and on 
information obtained subsequent to the utility RTC concerning HAP 
emissions to the atmosphere from electric utility steam generating 
units. In the utility RTC, the EPA indicated that coal- and oil-fired 
electric utility steam generating units are significant emitters of 
HAP, including mercury which is emitted from coal-fired units, and 
which EPA identified as the HAP of greatest concern to public health 
from the industry. Based on the available information, the 
Administrator finds that regulation of HAP emissions from coal- and 
oil-fired electric utility steam generating units under section 112 of 
the CAA is appropriate and necessary. As a result, this notice adds 
coal-and oil-fired electric utility steam generating units to the list 
of source categories under section 112(c) of the CAA. Also in the 
utility RTC, the EPA indicated that the impacts due to HAP emissions 
from natural gas-fired electric utility steam generating units were 
negligible based on the results of the study. The Administrator finds 
that regulation of HAP emissions from natural gas-fired electric 
utility steam generating units is not appropriate or necessary. The EPA 
does not believe that the definition of electric utility steam 
generating unit found in section 112(a)(8) of the CAA encompasses 
stationary combustion turbines. Therefore, the finding concerning 
natural-gas fired electric utility steam generating units does not 
apply to stationary combustion turbines.

ADDRESSES: Docket No. A-92-55, containing information used in 
development of this notice, is available for public inspection and 
copying between 8:00 a.m. and 5:30 p.m., Monday through Friday, 
excluding legal holidays. The docket is located in EPA's Air and 
Radiation Docket and Information Center, Waterside Mall, Room M-1500, 
401 M Street, SW, Washington, DC 20460, or by calling (202) 260-7548. A 
reasonable fee may be charged for copying docket materials.

FOR FURTHER INFORMATION CONTACT: Mr. William Maxwell, Emission 
Standards Division (MD-13), U.S. EPA, Research Triangle Park, North 
Carolina 27711, telephone number (919) 541-5430, facsimile number (919) 
541-5450, electronic mail address [email protected]>.

SUPPLEMENTARY INFORMATION: Docket. The docket is an organized file of 
all the information submitted to or otherwise relied upon by EPA in the 
development of this regulatory finding. The principal purpose of the 
docket is to allow interested parties to identify and locate documents 
that serve as a record of the process engaged in by EPA which resulted 
in the publication of today's finding.
    World Wide Web. In addition to being available in the docket, an 
electronic copy of today's notice will be posted on the Technology 
Transfer Network's (TTN) policy and guidance information page http://www.epa.gov/ttn/oarpg> under ``Recent Actions.'' The TTN provides 
information and technology exchange in various areas of air pollution 
control. If more information regarding the TTN is needed, call the TTN 
HELP line at (919) 541-5384.

I. What Is the Statutory Authority and Background of This Finding?

    Today's finding is issued under the authority of section 
112(n)(1)(A) and 112(c) of the CAA. Section 112(n)(1)(A) requires that, 
after considering the results of the study mandated by the same section 
and reported in the utility RTC, the Administrator determine whether 
regulation of HAP emissions from electric utility steam generating 
units is appropriate and necessary. The study was initiated following 
enactment of the 1990 Amendments to the CAA, which included section 
112(n)(1)(A). Data were gathered, and the utility RTC was prepared. 
Section 112(c) provides that the Administrator shall list categories of 
sources of the air pollutants contained in the section 112(b) list. The 
listing of source categories under section 112(c) is a dynamic process. 
(See ``Initial List of Categories of sources under Section 112(c)(1) of 
the Clean Air Act Amendments of 1990,'' 57 FR 31576.) Decisions as to 
the description and scope of source categories listed will be perfected 
during the course of the rulemaking process for each listed category 
and will take account of improvements in available information and 
analysis during the rulemaking. A draft utility RTC was submitted for 
scientific peer review in July 1995, and, concurrently, was made 
available for public review (60 FR 35393). A public meeting to obtain 
comments from the scientific peer review panel was held on July 11-12, 
1995 in Research Triangle Park, North Carolina. In addition, a public 
outreach meeting was held on July 13, 1995 in Durham, North Carolina, 
at which time the public was invited to present oral comments on its 
interpretation of the ``results of the study.'' The utility RTC was 
finalized in February 1998 and released to Congress and the public. In 
the final utility RTC, the EPA stated that, for the utility industry, 
mercury from coal-fired electric utility steam generating units was the 
HAP of greatest concern for public health.
    To further inform the regulatory finding, the EPA issued an 
information collection request under the authority of section 114 of 
the CAA to all coal-fired electric utility steam generating units 
requesting coal data from such units for calendar year 1999. Certain 
units were also required to conduct stack tests to evaluate their HAP 
emissions. In addition, the EPA solicited data from the public through 
a February 29, 2000 notice (65 FR 10783). Another public meeting was 
held on June 13, 2000 in Chicago, Illinois, where the public was 
invited to provide EPA with their views on what the regulatory finding 
should be (65 FR 18992).
    Further, the EPA undertook an evaluation of the mercury control 
performance of various emission control technologies that are either 
currently in use on electric utility steam generating units for 
pollutants other than mercury or that could be applied to such units 
for mercury control. The evaluation was conducted along with other 
parties, including the Department of Energy (DOE).
    In addition, at the direction of Congress, the EPA funded the 
National Academy of Sciences (NAS) to perform an independent evaluation 
of the available data related to the health impacts of methylmercury 
and provide recommendations for EPA's reference dose (RfD--the amount 
of a chemical which, when ingested daily over a lifetime, is 
anticipated to be without adverse health effects to humans, including 
sensitive subpopulations). The NAS conducted an 18-month study of the 
available data on the health effects of methylmercury and provided EPA 
a report of its findings in July 2000.

II. What Has EPA Learned From the Utility RTC and the Subsequent 
Data-Gathering Activities?

    The following four sections present a summary of the information 
and conclusions presented in the utility RTC along with the information 
obtained subsequent to publishing the utility RTC.

A. Health Hazard Assessment

    The EPA evaluated exposures, hazards, and risks due to HAP 
emissions from coal-, oil-, and natural gas-fired electric utility 
steam generating units. Much of the assessment focused on inhalation 
exposure. However, multipathway exposures (e.g., inhalation plus 
ingestion) were considered for six HAP

[[Page 79827]]

(mercury, radionuclides, arsenic, cadmium, lead, and dioxins). The 
assessment for radionuclides was relatively extensive and included 
multipathway modeling for all facilities identified in the utility RTC. 
The analysis for mercury was primarily based on information obtained 
from EPA's December 1997 ``Mercury Study Report to Congress'' (mercury 
RTC) and included a multipathway modeling assessment of mercury from 
four model electric utility plants. Screening level multipathway 
exposure modeling analyses were also conducted for arsenic and dioxins. 
For the other two HAP (cadmium and lead), a qualitative assessment of 
potential concerns for multipathway exposure was presented; 
multipathway modeling was not conducted for those two HAP. The methods 
and results of the analyses are presented in the utility RTC.
    Based on the assessment of hazards and risks due to emissions of 
HAP from electric utility steam generating units, mercury is the HAP of 
greatest concern. Mercury is highly toxic, persistent, and 
bioaccumulates in food chains. Mercury emitted from electric utility 
steam generating units (and other sources), primarily in the elemental 
or divalent forms, is transported through the atmosphere and eventually 
deposits onto land or water bodies (with the divalent form depositing 
nearer the source than the elemental form). Once deposited, the 
chemical form of mercury can change (through a methylation process) 
into methylmercury which is a highly toxic, more bioavailable, form 
that biomagnifies in the aquatic food chain (e.g., fish). Nearly all 
the mercury that accumulates in fish is methylmercury. Fish consumption 
dominates the pathway for human and wildlife exposure to mercury. As of 
July 2000, 40 States and American Samoa have issued fish advisories for 
mercury. Thirteen of those States have issued advisories for all water 
bodies in their State, and the other 27 States have issued advisories 
for over 1,900 specific water bodies.
    Because the developing fetus is the most sensitive to the effects 
of methylmercury, the greatest concern is the consumption of mercury 
contaminated fish by women of childbearing age. Also of particular 
concern are subsistence fish-eating populations that may be consuming 
fish from contaminated waterbodies. The EPA estimates that about 7 
percent of women of childbearing age (i.e., between the ages of 15 and 
44 years) are exposed to methylmercury at levels exceeding its RfD of 
0.1 microgram per kilogram body weight per day (0.1 ug/kg/day). The 
risk following exposures above the RfD is uncertain, but risk increases 
with increasing exposure. About 1 percent of women have methylmercury 
exposures 3 to 4 times the methylmercury RfD. The NAS, in its July 2000 
report ``Toxicological Effects of Methylmercury,'' affirmed EPA's 
assessment of methylmercury toxicity and the level of its RfD.
    Most of the mercury currently entering U.S. water bodies and 
contaminating fish is the result of air emissions which, following 
atmospheric transport, deposit onto watersheds or directly to water 
bodies. Wastewater discharges also contribute to environmental 
loadings, but to a much lesser degree than air emissions. Based on 
modeling conducted for the mercury RTC, the EPA estimates that roughly 
60 percent of the total mercury deposited in the U.S. comes from U.S. 
anthropogenic air emission sources; the percentage is estimated to be 
even higher in certain regions (e.g., northeast U.S.). The remainder of 
the mercury deposited from the air comes from natural emission sources, 
reemissions of historic global anthropogenic mercury releases, and from 
anthropogenic sources outside the U.S. In the mercury RTC, the EPA 
concluded that, given the total mass of mercury estimated to be emitted 
from all anthropogenic sources and EPA's modeling of the atmospheric 
transport of emitted mercury, coal combustion and waste incineration 
most likely bear the greatest responsibility for direct anthropogenic 
mercury deposition to the continental U.S. Mercury emissions from waste 
incineration (including municipal waste combustors and hospital/
medical/infectious waste incinerators) have been declining 
substantially over the last decade largely due to regulations issued by 
EPA. Electric utility steam generating units (which are not currently 
regulated for mercury emissions) are the largest source of mercury 
emissions in the U.S., estimated to emit about 30 percent of current 
U.S. anthropogenic emissions. There is a plausible link between 
emissions of mercury from anthropogenic sources (including coal-fired 
electric utility steam generating units) and methylmercury in fish. 
Therefore, mercury emissions from electric utility steam generating 
units are considered a threat to public health and the environment. It 
is acknowledged that there are uncertainties regarding the extent of 
the risks due to electric utility mercury emissions. For example, there 
is no quantification of how much of the methylmercury in fish consumed 
by the U.S. population is due to electric utility emissions relative to 
other mercury sources (e.g., natural and other anthropogenic sources). 
Nonetheless, the available information indicates that mercury emissions 
from electric utility steam generating units comprise a substantial 
portion of the environmental loadings and are a threat to public health 
and the environment. The EPA believes that it is not necessary to 
quantify the amount of mercury in fish due to electric utility steam 
generating unit emissions relative to other sources for the purposes of 
this finding.
    With regard to the other HAP, arsenic and a few other metals (e.g., 
chromium, nickel, cadmium) are of potential concern for carcinogenic 
effects. Although the results of the risk assessment indicate that 
cancer risks are not high, they are not low enough to eliminate those 
metals as a potential concern for public health. Dioxins, hydrogen 
chloride, and hydrogen fluoride are three additional HAP that are of 
potential concern and may be evaluated further during the regulatory 
development process.
    The other HAP studied in the risk assessment do not appear to be a 
concern for public health based on the available information. However, 
because of data gaps and uncertainties, it is possible that future data 
collection efforts or analyses may identify other HAP of potential 
concern.

B. Emissions

    In developing the utility RTC, the EPA examined HAP emissions test 
data acquired by the DOE, electric utility companies and organizations, 
and EPA itself. Further, using section 114 authority, the EPA obtained 
data from each coal-fired electric utility unit to update and refine 
the information on mercury emissions from such units. After evaluating 
various methods to estimate the emissions, the EPA estimates that the 
industry emitted 43 tons of mercury in 1999 from 1,149 units at 464 
coal-fired plants.
    The analyses of the data obtained are explained in the utility RTC 
and in subsequent documentation. Table 1 of this notice presents 
estimated 1990 and 2010 nationwide HAP emissions from electric utility 
steam generating units as presented in the utility RTC. The estimates 
account for projected changes in the population of units, fuel 
consumption, and control device configurations. Coal- and oil-fired 
electric utility steam generating units are major sources (as defined 
in section 112(a)(1) of the CAA) of hydrogen chloride and hydrogen 
fluoride emissions, emit a significant number of

[[Page 79828]]

the 188 HAP on the section 112(b) list, and are the leading 
anthropogenic sources of mercury emissions in the U.S.

                                                  Table 1.--Selected Nationwide Estimated HAP Emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Selected nationwide HAP
                                                            emissions estimates  (tons/  ---------------------------------------------------------------
                                                                       year)                            Oil                         Natural gas
                           HAP                           -----------------------------------------------------------------------------------------------
                                                                       Coal
                                                         --------------------------------      1990            2010            1990            2010
                                                               1990            2010
--------------------------------------------------------------------------------------------------------------------------------------------------------
Arsenic.................................................              61              71               5               3            0.15            0.25
Beryllium...............................................             7.1             8.2             0.5             0.4
Cadmium.................................................             3.3             3.8             1.7             0.9
Chromium................................................              73              87             4.7             2.4
Dioxins.................................................        0.000097        0.000108      2  x  10-5      3  x  10-6
Formaldehyde............................................  ..............  ..............  ..............  ..............              36              57
Hydrogen chloride.......................................         143,000         155,000           2,860           1,450
Hydrogen fluoride.......................................          19,500          27,500
Lead....................................................              75              87            10.6             5.4
Manganese...............................................             164             219             9.3             4.7
Mercury.................................................              46              60            0.25            0.13
Nickel..................................................  ..............  ..............             393             198             2.2             3.5
--------------------------------------------------------------------------------------------------------------------------------------------------------

    For mercury, it was estimated in the utility RTC that the industry 
emitted approximately 46 tons in 1990 (51 tons in 1994) and was 
projected to emit approximately 60 tons in 2010 from 1,026 units at 426 
coal-fired plants. The new information obtained under section 114 
authority corroborates the emissions estimates. The increase in the 
number of units over that of the utility RTC results primarily from the 
identification of additional co-generation facilities meeting the 
section 112(a)(8) definition. The quality of the 1999 data is 
considered to be significantly better than that of the data reported in 
the utility RTC. Specific coal data, including the mercury content, 
were obtained for each coal-fired unit in the U.S. over the entire 
year; previously, State-average data were used. In addition, the 
control performance of existing control devices for each of the three 
major species of mercury (divalent, elemental, and particulate) were 
available; for the utility RTC, only total mercury values were 
available. The new data allowed EPA to significantly refine and improve 
its analyses and evaluate various methodologies in estimating 
nationwide mercury emissions from coal-fired electric utility steam 
generating units.

C. Alternative Control Strategies

    Recent data show the technologies used to control criteria 
pollutants (particulate matter (PM), nitrogen oxides ( NOX) 
and sulfur dioxide (SO2)) are effective in controlling 
emissions of nearly all HAP except mercury. In addition, combinations 
of controls for criteria pollutants can lead to varying levels of 
control, and in some cases full control, of mercury emissions. The 
application of technologies used to control mercury emissions in 
conjunction with technologies used to control other pollutants, an 
approach called multipollutant control, can substantially reduce or 
offset the costs of HAP control.
    Potential strategies for controlling mercury and other HAP 
emissions include the use of: precombustion controls (e.g., fuel 
switching, coal switching, coal cleaning); combustion modification 
methods used to control NOX emissions; flue gas cleaning 
technologies that can be used to control emissions of criteria 
pollutants and HAP; and nontraditional controls such as demand side 
management and energy conservation.
    Conversion of coal- and oil-fired units to natural gas firing 
effectively eliminates HAP emissions. Although conversion of coal-fired 
units to oil combustion will decrease emissions of some HAP, including 
mercury, it could increase emissions of others (especially nickel). 
Because of the wide variability in the trace metal contents of coals, 
switching coals generally may not result in consistently reduced HAP 
emissions. Current methods of coal cleaning remove portions of the 
trace metals contained within the coal; the average emissions 
reductions range from approximately 30 percent for mercury to 
approximately 50 percent for lead.
    Nontraditional control methods (e.g., demand side management, 
energy conservation, pollution prevention) have the potential to result 
in reduced HAP emissions, but the extent to which that is possible is 
currently uncertain. The nontraditional controls reduce HAP emissions 
through the avoided generation of HAP rather than by their removal from 
the exhaust gas stream.
    Mercury in the flue gas from coal combustion may be present in 
three different forms. The forms, called species, include elemental 
mercury, divalent oxidized forms, and mercury adsorbed onto the surface 
of fly ash or other particles. The capture of mercury is highly 
dependent on the relative amount of mercury species that are present in 
the flue gas. Particulate bound mercury can easily be removed in 
conventional PM emission control devices such as electrostatic 
precipitators (ESP) and fabric filters (FF). Divalent forms of mercury 
are generally soluble in water and can be captured in wet scrubbers. 
Wet flue gas desulfurization (FGD) systems generally capture more than 
90 percent of the divalent mercury, which may represent a 20 to 80 
percent removal of the total mercury. Elemental mercury is insoluble in 
water, does not react with alkaline reagents used in FGD systems, and 
cannot be captured in wet scrubbers. Both the elemental and divalent 
forms of mercury can be adsorbed onto porous solids (e.g., fly ash, 
powdered activated carbon, calcium-based acid gas sorbents) for 
subsequent removal in a PM control device, although elemental mercury 
is more difficult to adsorb onto solid surfaces than are the divalent 
forms of mercury. Bituminous coals contain higher concentrations of 
chlorine and other constituents that promote the oxidation and capture 
of mercury in conventional air pollution control devices. In contrast, 
flue gas from the combustion of subbituminous and lignite coals 
typically have higher amounts of the more difficult to control 
elemental form of mercury.
    The available data indicate that installation of low-NOX 
burners and

[[Page 79829]]

other combustion modification methods in pulverized coal-fired units 
may increase the carbon content of the fly ash. Mercury emissions may 
then be reduced through adsorption onto the fly ash carbon and 
subsequent capture in the PM control device. The improved mercury 
capture may come at the expense of slightly higher emissions of organic 
HAP. Cyclone-fired units emit low amounts of fly ash and reduce the 
chances of mercury adsorption and capture as particle-bound mercury. 
Fluidized bed combustion systems typically have high flue gas 
concentrations of high carbon-content fly ash and high levels of 
mercury capture in PM emission control devices.
    Electrostatic precipitators and FF generally remove greater than 90 
percent of all trace metallic HAP, with the exception of mercury. They 
are not effective in reducing emissions of gas-phase HAP, which include 
trace organic HAP and HAP such as hydrogen chloride and hydrogen 
fluoride.
    Mechanical collectors and wet PM scrubbers are not generally 
effective in reducing HAP emissions. Mechanical collectors capture only 
HAP that are associated with large particles; fine-particle HAP and 
gas-phase HAP pass through and are emitted to the atmosphere. Wet PM 
scrubbers are moderately effective in reducing water-soluble HAP but do 
not effectively reduce HAP emissions associated with fine particulate 
or hydrophobic volatile organic HAP.
    Dry scrubbers which employ a spray dryer adsorber (SDA) in 
conjunction with an ESP or FF are typically very effective in reducing 
HAP emissions. In SDA systems, water containing an acid gas sorbent is 
sprayed into a reaction vessel where the acid gases and other 
pollutants are reacted to form solid particles that can be collected in 
a downstream PM control device. Some coal-fired utilities that use 
bituminous coal in pulverized coal-fired units have shown mercury 
capture in excess of 90 percent in SDA/FF systems.
    Wet FGD systems are capable of capturing nearly all HAP other than 
mercury and more than 90 percent of the divalent and particle bound 
mercury. Mercury removal in wet FGD systems may range from less than 20 
to more then 80 percent, depending on the type of coal and combustion 
system used. Mercury capture in such units can be improved by the use 
of catalysts or reagents to increase the conversion of elemental 
mercury to soluble divalent forms of mercury.
    Recent research indicates that mercury removal may be enhanced 
through the use of oxidizing agents (that convert elemental mercury to 
the ionized form) or through the use of sorbents (that adsorb the 
mercury onto solid particles). Enhanced mercury removal may also be 
achieved through greater use of multipollutant control options. Recent 
data indicate that the use of selective catalytic or noncatalytic 
reduction for NOX control may also oxidize mercury and, 
therefore, enhance mercury control.
    Thus, EPA's analysis of potential HAP control strategies allows EPA 
to conclude that, during the regulatory development process, effective 
controls for mercury and other HAP can be shown to be feasible.

D. Conclusions

    The following conclusions summarize those presented in the utility 
RTC and those based on the information subsequently obtained and are 
based on the currently available scientific data. The conclusions, as a 
whole, support a finding that regulation of coal-and oil-fired electric 
utility steam generating units for HAP is appropriate and necessary.
    1. Fossil fuel-fired electric utility steam generating units (coal-
and oil-fired units in particular) emit a significant number of the 188 
HAP included on the section 112(b) list. Estimated growth in the number 
of, and fuel use by, electric utility steam generating units 
(particularly coal-fired units) during the period 1990 to 2010 will 
result in an overall increase in HAP emissions. The new data gathered 
to date corroborate the previous nationwide mercury emissions estimate 
and confirm that electric utility steam generating units are the 
largest anthropogenic source of mercury in the U.S.
    2. Mercury is highly toxic, persistent, and bioaccumulates in the 
food chain. Mercury emissions are transported through the atmosphere 
and eventually deposit onto land or water bodies. The deposition can 
occur locally near the source or at long distances (e.g., hundreds or 
thousands of miles away). The air transport and deposition patterns of 
mercury emissions depend on various factors, including: The form of 
mercury released (divalent mercury deposits nearer to the source 
whereas elemental mercury enters the global pool and deposits farther 
from the source); the stack height and meteorology; and chemical 
transformations during transport in the atmosphere. Once deposited, the 
chemical form of mercury can change into methylmercury (through a 
methylation process), which is a more toxic form that biomagnifies up 
the aquatic food chain. Fish consumption dominates the pathway for 
human and wildlife exposure to mercury. There is a plausible link 
between emissions of mercury from anthropogenic sources (including 
coal-fired electric utility units) and methylmercury in fish.
    3. Neurotoxicity is the health effect of greatest concern with 
methylmercury exposure. Methylmercury has a relatively long half-life 
in the human body (averaging about 70 to 80 days). Dietary 
methylmercury is almost completely absorbed into the blood and 
distributed to all tissues including the brain; it also readily passes 
through the placenta to the fetus and fetal brain. The developing fetus 
is considered most sensitive to the effects from methylmercury; 
therefore, women of childbearing age are the population of greatest 
concern. Offspring born of women exposed to relatively high levels of 
methylmercury during pregnancy have exhibited a variety of 
developmental neurological abnormalities, including delayed 
developmental milestones, cerebral palsy, and reduced neurological test 
scores. Studies suggest that far lower levels of in utero exposures 
have resulted in delays and deficits in learning abilities. It is also 
possible that children exposed after birth are also potentially more 
sensitive to the toxic effects of methylmercury than adults because 
their nervous systems are still developing.
    4. Extrapolating from high-dose exposure incidents, the EPA derived 
an RfD for methylmercury of 0.1 ug/kg/day based on developmental 
neurological effects observed in children born to mothers exposed to 
methylmercury during their pregnancy. The NAS study determined that 
EPA's RfD is a scientifically justifiable level for the protection of 
public health. At the RfD or below, exposures are expected to be safe. 
The risks following exposures above the RfD are uncertain, but risk 
increases as exposures to methylmercury increase.
    5. The results of recent dietary surveys indicate that most of the 
U.S. population consumes fish and is exposed to methylmercury as a 
result. Based on the surveys, about 85 percent of adults in the U.S. 
consume fish at least once a month, about 40 percent of adults consume 
fish once a week, and 1 to 2 percent of adults consume fish almost 
daily.
    6. The EPA estimates that about 7 percent of women of childbearing 
age (i.e., between the ages of 15 and 44 years) are exposed to 
methylmercury at levels exceeding the RfD and about 1

[[Page 79830]]

percent of women have methylmercury exposures 3 to 4 times that level.
    7. Exposure to methylmercury can have serious toxicologic effects 
on wildlife as well as on humans. Adverse effects to avian species and 
wildlife have been observed in laboratory studies at levels 
corresponding to fish tissue methylmercury concentrations that are 
exceeded by a significant percentage of fish sampled in lake surveys. 
Generally, wildlife consume fish from a much more limited geographic 
area than do humans which can result in elevated levels of mercury in 
certain fish-eating species in localized geographic areas. Those 
species can include kingfisher, river otter, racoon, loon, as well as 
some endangered species such as the Florida panther.
    8. The EPA predicts that increased mercury deposition will lead to 
increased levels of methylmercury in fish, and that increased levels in 
fish will lead to toxicity in fish-eating birds and mammals, including 
humans. The NAS, in its July 2000 report, stated that ``because of the 
beneficial effects of fish consumption, the long-term goal needs to be 
a reduction in the concentrations of methylmercury in fish.'' The EPA 
agrees with that goal and believes that reducing emissions of mercury 
from electric utility steam generating units is an important step 
toward achieving the goal.
    9. There are a number of alternative control strategies that are 
effective in controlling some of the HAP emitted from electric utility 
steam generating units. Recent data indicate that mercury, perhaps the 
hardest HAP to remove from the exhaust gas stream, can be effectively 
removed by using oxidizing agents or sorbents injected into the gas 
stream. Recent data also indicate the possibility for multipollutant 
control with other pollutants (e.g., NOX, SO2, 
and PM), greatly reducing mercury control costs.

III. What Is EPA's Regulatory Finding?

    Based on the results of the study documented in the utility RTC, as 
well as subsequent analyses and other available information, the 
Administrator has concluded that mercury is both a public health 
concern and a concern in the environment. The Administrator has 
concluded that there is a plausible link between methylmercury 
concentrations in fish and mercury emissions from coal-fired electric 
utility steam generating units. Although the degree to which that 
linkage occurs cannot be estimated quantitatively now, the facts are 
that: There is a linkage between coal consumption and mercury 
emissions; electric utility steam generating units are the largest 
domestic source of mercury emissions; and certain segments of the U.S. 
population (i.e., the developing fetus, subsistence fish-eating 
populations) are believed to be at potential risk of adverse health 
effects due to mercury exposures resulting from consumption of 
contaminated fish. Further, there remain uncertainties regarding the 
extent of the public health impact from HAP emissions from oil-fired 
electric utility steam generating units. Those facts and uncertainties 
lead the Administrator to find that regulation of HAP emissions from 
coal- and oil-fired electric utility steam generating units under 
section 112 is appropriate and necessary. It is appropriate to regulate 
HAP emissions from coal- and oil-fired electric utility steam 
generating units under section 112 of the CAA because, as documented in 
the utility RTC and stated above, electric utility steam generating 
units are the largest domestic source of mercury emissions, and mercury 
in the environment presents significant hazards to public health and 
the environment. The NAS study confirms that mercury in the environment 
presents significant hazards to public health. Further, it is 
appropriate to regulate HAP emissions from such units because EPA has 
identified a number of control options which EPA anticipates will 
effectively reduce HAP emissions from such units. It is necessary to 
regulate HAP emissions from coal- and oil-fired electric utility steam 
generating units under section 112 of the CAA because the 
implementation of other requirements under the CAA will not adequately 
address the serious public health and environmental hazards arising 
from such emissions identified in the utility RTC and confirmed by the 
NAS study, and which section 112 is intended to address. Therefore, the 
EPA is adding coal- and oil-fired electric utility steam generating 
units to the list of source categories under section 112(c) of the CAA. 
As a part of developing a regulation, the effectiveness and costs of 
controls will be examined along with the level(s) of control that may 
be technically feasible.
    In developing a regulation under section 112(d), the statute 
authorizes EPA to consider subcategorization of a source category. The 
emissions standard for existing sources cannot be less stringent than 
the average emissions limitation achieved by the best performing 12 
percent of existing sources in the category or subcategory (the 
``floor''). However, the EPA intends to develop a record to facilitate 
consideration of subcategorization of the source category in setting 
the ``floor.'' Based on the information that EPA has to date, the EPA 
anticipates that a factual record will allow EPA to propose appropriate 
subcategories for this source category. In developing standards under 
section 112(d) to date, the EPA has based subcategorization on 
considerations such as: the size of a facility; the type of fuel used 
at the facility; and the plant type. The EPA also may consider other 
relevant factors such as geographic conditions in establishing 
subcategories. Once the source category is divided into subcategories, 
the EPA determines the ``floor'' for each subcategory and, in turn, the 
emissions standard independently for each subcategory. This approach 
has helped build flexibility in meeting environmental objectives in the 
past.
    Once the floor is determined, the EPA can set an emissions standard 
that is more stringent than the floor if a tighter level of control is 
technically achievable and is justified. Factors that must be 
considered in deciding whether a more stringent standard than the floor 
is justified include: the cost of a more stringent standard; the energy 
requirements; and any non-air quality health and environmental factors.
    Every source has to meet the level of a standard set under section 
112(d), but not necessarily every individual unit at a source. Most 
electric generating plants have several units and so in meeting the 
standard there may be opportunity for lower cost solutions because the 
law allows for differences in reductions among units as long as the 
source as a whole is in compliance.
    There is considerable interest in an approach to mercury regulation 
for power plants that would incorporate economic incentives such as 
emissions trading. Such an approach can reduce the cost of pollution 
controls by allowing for least-cost solutions among a universe of 
facilities that face different control costs. Trading also can allow 
for a greater level of control overall because it offers the 
opportunity for greater efficiency in achieving control. The EPA, 
however, recognizes and shares concerns about the local impacts of 
mercury emissions and any regulatory scheme for mercury that 
incorporates trading or other approaches that involve economic 
incentives must be constructed in a way that assures that communities 
near the sources of emissions are adequately protected. Thus, in 
developing a standard for utilities, the EPA should consider the legal 
potential for, and the economic effects of, incorporating a trading 
regime

[[Page 79831]]

under section 112 in a manner that protects local populations.
    The Administrator finds that regulation of HAP emissions from 
natural gas-fired electric utility steam generating units is not 
appropriate or necessary because the impacts due to HAP emissions from 
such units are negligible based on the results of the study documented 
in the utility RTC.
    The EPA has previously indicated that it construes the term 
``electric utility steam generating unit,'' as defined in section 
112(a)(8) of the CAA and 40 CFR 63.41, to exclude all stationary 
combustion turbines, regardless of whether such turbines are used to 
generate electricity or used by an electric utility, and regardless of 
whether such turbines are used in conjunction with waste heat recovery 
units (65 FR 34010). Therefore, the finding concerning natural-gas 
fired electric utility steam generating units does not apply to 
stationary combustion turbines.

IV. Is This Action Subject to Judicial Review?

    Today's finding that it is appropriate and necessary to regulate 
coal-and oil-fired electric utility steam generating units adds these 
units to the list of source categories under section 112(c). Section 
112(e)(4) of the CAA states that, notwithstanding section 307 of the 
CAA, no action of the Administrator listing a source category or 
subcategory under section 112(c) shall be a final EPA action subject to 
judicial review, except that any such action may be reviewed under 
section 307 when the Administrator issues emissions standards for such 
pollutant or category. Therefore, today's finding is not subject to 
judicial review. As specified by section 112(e)(4), judicial review 
would be available on both the listing decision and the subsequent 
regulation at the time that such final regulation is promulgated. At 
such time, the exact dimensions of the source category and the nature 
of the control required would be sufficiently clear to allow for 
judicial review.

V. Is EPA Asking for Public Comment?

    The EPA has held several public meetings wherein oral and written 
public input were solicited and obtained regarding the regulatory 
finding. In addition, numerous opportunities for written comment 
relating to both the study and the regulatory finding have been 
provided. The EPA has decided that it is unnecessary to solicit 
additional public comment on today's finding. The regulation developed 
subsequent to the finding will be subject to public review and comment.

VI. Administrative Requirements

    Today's notice does not impose regulatory requirements or costs. 
Therefore, the requirements of Executive Order 13045 (Protection of 
Children from Environmental Health Risks and Safety Risks), Executive 
Order 13084 (Consultation and Coordination with Indian Tribal 
Governments), Executive Order 13132 (Federalism), the Regulatory 
Flexibility Act, the National Technology Transfer and Advancement Act, 
and the Unfunded Mandates Reform Act do not apply to today's notice. 
Also, this notice does not contain any information collection 
requirements and, therefore, is not subject to the Paperwork Reduction 
Act, 44 U.S.C. 3501 et seq. This notice was reviewed by the Office of 
Management and Budget under Executive Order 12866 (58 FR 51735, October 
4, 1993).

    Dated: December 14, 2000.
Carol M. Browner,
Administrator.
[FR Doc. 00-32395 Filed 12-19-00; 8:45 am]
BILLING CODE 6560-50-U