[Federal Register Volume 64, Number 116 (Thursday, June 17, 1999)]
[Proposed Rules]
[Pages 32458-32464]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-15435]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[FRL-6362-5]
RIN 2060-ZA07


Assessment of Visibility Impairment at the Grand Canyon National 
Park: Advance Notice of Proposed Rulemaking

AGENCY: Environmental Protection Agency.

ACTION: Advance notice of proposed rulemaking.

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SUMMARY: The Environmental Protection Agency (EPA) is providing advance 
notice of proposed rulemaking regarding visibility impairment at the 
Grand Canyon National Park (GCNP) and the possibility that the Mohave 
Generating Station (MGS) in Laughlin, Nevada may contribute to that 
impairment. The purpose of this advance notice is to explain provisions 
in the Clean Air Act and EPA regulation for protecting visibility in 
national parks and wilderness areas. This notice also describes the 
Department of the Interior (DOI) certification of visibility impairment 
at the Grand Canyon and the statement made by the Department that it 
believes the MGS is contributing to this impairment. This notice also 
presents a summary of the methodologies and results of Project MOHAVE, 
the study which evaluated the impacts of emissions from the MGS on 
visibility at the GCNP. In this notice, EPA is also requesting 
additional information that it should consider in determining whether 
visibility problems at the GCNP can be reasonably attributed to MGS, 
and if so, what, if any, pollution control requirements should be 
applied. EPA is not proposing any specific action regarding the MGS at 
this time but is providing background information and requesting 
additional information that the agency should consider.

DATES: Comments on this advanced notice of proposed rulemaking must be 
submitted no later than August 16, 1999.

ADDRESSES: Comments should be submitted (in duplicate, if possible) to: 
EPA Region IX, 75 Hawthorne Street (AIR2), San Francisco, CA 94105, 
Attn: Regina Spindler (Phone: 415-744-1251).
    Docket: EPA has established a docket for this document, Docket 
Number A2-99-01. Materials related to the development of this notice 
have been placed in this docket. The docket is available for review at: 
EPA Region IX, Air Division, 75 Hawthorne Street, San Francisco, CA 
94105. Interested persons may make an appointment with Regina Spindler, 
(415) 744-1251, to inspect the docket at EPA's San Francisco office on 
weekdays between 9 a.m. and 4 p.m.
    Electronic Availability: This document is also available as an 
electronic file on the EPA Region IX Web Page at http://www.epa.gov/
region09.

FOR FURTHER INFORMATION CONTACT: Regina Spindler (415) 744-1251, 
Planning Office (AIR2), Air Division, EPA Region IX, 75 Hawthorne 
Street, San Francisco, CA 94105.

SUPPLEMENTARY INFORMATION:

Outline

I. Background
    A. Statutory and Regulatory Framework
    1. Clean Air Act Visibility Requirements
    2. EPA's Visibility Regulations
    3. Federal Implementation Plans for Visibility Protection
    4. ``Reasonable Attribution'' Determination for Navajo 
Generating Station
    B. The Department of the Interior Certification of Visibility 
Impairment

[[Page 32459]]

    C. The Mohave Generating Station
II. Information Available for ``Reasonable Attribution'' Analysis
    A. Project MOHAVE
    B. Other Available Information
III. Request for Public Comment
    A. ``Reasonable Attribution'' Determination
    B. ``Best Available Retrofit Technology'' Analysis
IV. Activities Related to the Mohave Generating Station and 
Visibility Impairment at the Grand Canyon National Park
    A. Grand Canyon Visibility Transport Commission
    B. Public Meeting
    C. Grand Canyon Trust/Sierra Club Lawsuit
    D. Environmental Defense Fund Letter
    E. Southern California Edison Proposal
V. Administrative Requirements
    A. Executive Order 12866
    B. Regulatory Flexibility

I. Background

A. Statutory and Regulatory Framework

1. Clean Air Act Visibility Requirements
    Section 169A of the Clean Air Act (Act or CAA), 42 U.S.C. 7491, 
provides for a visibility protection program and sets forth as a 
national goal ``the prevention of any future, and the remedying of any 
existing, impairment of visibility in mandatory Class I Federal areas 
which impairment results from manmade air pollution.'' (The terms 
``impairment of visibility'' and ``visibility impairment'' are defined 
in the Act to include reduction in visual range and atmospheric 
discoloration.) Section 169A requires EPA, after consultation with the 
Secretary of the Interior, to promulgate a list of ``mandatory Class I 
Federal areas'' where visibility is an important value. These areas 
include international parks, national wilderness areas and national 
memorial parks greater than five thousand acres in size, and national 
parks greater than six thousand acres in size, as described in section 
162(a) of the Act, 42 U.S.C. 7472(a). Each mandatory Class I Federal 
area is the responsibility of a Federal Land Manager (FLM), the 
Secretary of the federal department with authority over such lands. 
Section 302(i) of the Act, 42 U.S.C. 7602(i). On November 30, 1979, EPA 
identified 156 such mandatory Class I Federal areas, including the 
Grand Canyon National Park in Arizona. 44 FR 69122.
    Section 169A(a)(1) of the Act states that ``Congress declares as a 
national goal the prevention of any future, and the remedying of any 
existing, impairment of visibility in mandatory class I Federal areas 
which impairment results from manmade air pollution.'' Section 
169A(a)(4) requires EPA to promulgate regulations to assure reasonable 
progress toward meeting these national visibility protection goals. 
EPA's regulations must require each state with a mandatory Class I 
Federal area (or states with emissions that may reasonably be 
anticipated to cause or contribute to visibility impairment in a 
mandatory Class I Federal area) to revise the applicable implementation 
plan for that state (SIP) to contain such emission limits, schedules of 
compliance and other measures as may be necessary to make reasonable 
progress toward meeting the national visibility protection goal. CAA 
section 169A(b)(2), 42 U.S.C. 7491(b)(2). The SIP revisions for these 
subject states must require each existing major stationary source 
1 that emits any air pollutant that may reasonably be 
anticipated to cause or contribute to visibility impairment in a 
mandatory Class I Federal area to install and operate ``best available 
retrofit technology'' (BART) for controlling emissions from such source 
to eliminate or reduce visibility impairment. CAA section 
169A(b)(2)(A), 42 U.S.C. 7491(b)(2)(A). Pursuant to section 
169A(b)(2)(B) of the Act, 42 U.S.C. 7491(b)(2)(B), EPA's regulations 
must further require these states to include long term strategies in 
their SIP revisions for making reasonable progress toward meeting the 
national goal. Section 110(a)(2)(J) of the Act, 42 U.S.C. 
7410(a)(2)(J), provides a corollary provision that requires SIPs to 
meet the visibility protection requirements of part C of the Clean Air 
Act.
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    \1\ For purposes of the visibility protection requirements, the 
term ``major stationary source'' in the statute generally means any 
of a list of 26 different categories of stationary sources of air 
pollutants, which has the potential to emit 250 tons per year or 
more of any air pollutant. CAA section 169A(g)(7), 42 U.S.C. 
7491(g)(7). The statutory provisions apply to such ``major 
stationary sources'' which were not in operation prior to August 7, 
1962, and were in existence on August 7, 1977. CAA section 
169A(b)(2)(A), 42 U.S.C. 7491(b)(2)(A). The term ``existing 
stationary facility'' is defined to include these statutory 
criteria. In addition, the definition of ``existing stationary 
facility'' includes any reconstructed source and provides that 
fugitive emissions are included in determining the potential 
emissions from a source. 40 CFR 51.301(e).
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2. EPA's Visibility Regulations
    On December 2, 1980, EPA promulgated what it described as the first 
phase of the required visibility regulations, codified at 40 CFR 
51.300-307. (45 FR 80084). These visibility regulations apply to 36 
states, including Nevada, that contain mandatory Class I Federal areas. 
The visibility regulations require these 36 states to comply with the 
requirements set forth above, including (1) coordinating development of 
SIP requirements with appropriate FLMs; (2) developing a program to 
assess and remedy visibility impairment from new and existing sources; 
(3) developing a long-term strategy (10-15 years) to assure reasonable 
progress toward the national visibility goal; (4) developing a 
visibility monitoring strategy to collect information on visibility 
conditions; and (5) considering in all aspects of visibility protection 
any ``integral vistas'' (important views of landmarks or panoramas that 
extend outside of the boundaries of the Class I area) identified by the 
FLMs as critical to a visitor's enjoyment of the Class I area. 40 CFR 
51.300-307.2
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    \2\ These visibility regulations only address the type of 
visibility impairment that is ``reasonably attributable'' to a 
single source or small group of sources. In 1980 when EPA 
promulgated these regulations, EPA deferred setting SIP requirements 
to address visibility impairment caused by ``regional haze'' (i.e., 
a widespread, regionally homogeneous haze from a multitude of 
sources which impairs visibility in every direction over a large 
area) due to the complexity and technical limitations inherent in 
attempting to identify, measure, and control this type of widespread 
visibility impairment. In 1993, the National Academy of Sciences 
concluded that ``current scientific knowledge is adequate and 
control technologies are available for taking regulatory action to 
improve and protect visibility.'' EPA promulgated regulations to 
address regional haze on April 22, 1999.
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    An FLM may, at any time, certify to a state that impairment of 
visibility exists in a mandatory Class I Federal area. 40 CFR 
51.302(c). If the FLM certifies such impairment at least 6 months prior 
to submission of a revised SIP, an affected state must (1) identify 
each existing stationary facility which may ``reasonably be anticipated 
to cause or contribute'' to any impairment which is ``reasonably 
attributable to that existing stationary facility,'' and (2) analyze 
and determine what emission limitation represents the ``best available 
retrofit technology'' at each such facility. 40 CFR 51.302(c)(4). 
Visibility impairment is ``reasonably attributable'' to a facility if 
it is ``attributable by visual observations or any other technique the 
state deems appropriate.'' 40 CFR 51.301(s). The state must also 
include in its plan an assessment of visibility impairment and a 
discussion of how each element of the plan relates to preventing future 
or remedying existing impairment in any mandatory Class I Federal area 
in the state. 40 CFR 51.302(c)(2)(ii). The visibility regulations also 
provide for periodic review, and revision as appropriate, of the long-
term strategy for making reasonable progress toward the visibility 
goals at a minimum frequency of every three years. 40 CFR 51.306(c). 
The 36

[[Page 32460]]

affected states were required to submit revisions to their SIPs to 
comply with these requirements by September 2, 1981. 40 CFR 
51.302(a)(1).
3. Federal Implementation Plans for Visibility Protection
    Most states did not meet the September 2, 1981 deadline for 
submitting a SIP revision to address visibility protection. A number of 
environmental groups filed a citizen suit seeking to compel EPA to 
promulgate its own visibility implementation plans for the states that 
had failed to submit SIPs to EPA, pursuant to section 110(c) of the 
Act. In the final rule published on November 24, 1987, EPA disapproved 
the SIPs of 29 states, including Nevada, for failure to comply with the 
visibility SIP requirements of 40 CFR 51.300-307. In order to implement 
the visibility protection program, EPA promulgated a federal 
implementation plan (FIP) for each state that failed to submit a 
visibility plan, including Nevada. 52 FR 45132 (November 24, 1987) 
codified at 40 CFR 52.27, 52.29 and 52.1488. See also 40 CFR 52.26 and 
52.28.
    In the preamble to the proposed FIP, EPA addressed certifications 
of existing visibility impairment (i.e., certifications of impairment 
that the FLM submitted prior to June 1, 1986) submitted by the FLM. The 
FLM certified that there was impairment in all Class I areas in the 
lower 48 states. EPA reviewed the certification for each Class I area, 
and determined that there was insufficient information or technical 
support to determine if the impairment existed within certain Class I 
areas, or to positively attribute impairment to any specific source or 
sources. In other Class I areas, research was underway but not yet 
completed to better characterize and identify the sources of 
impairment. In one other area, EPA had approved the SIP for visibility 
in that state and assumed that the certification of impairment would be 
addressed in the periodic report required by the state's visibility 
SIP. 52 FR 7802, 7805-7807 (March 12, 1987). For these reasons, EPA 
determined that, as of the final rulemaking (November 24, 1987), states 
were not required to include Best Available Retrofit Technology (BART) 
requirements in their implementation plans to address existing 
impairment. 52 FR 45132, 45133-45134. The EPA, however, acknowledged 
that information could become available in the future indicating 
impairment and that the FLM could certify the existence of visibility 
impairment at any time. Any future certifications of visibility 
impairment would be addressed by either the state or EPA (if the state 
SIP remains disapproved for visibility protection). 52 FR 45132, 45136.
    In the visibility protection FIP, EPA established requirements for 
visibility monitoring, new source review (in attainment and 
nonattainment areas) and a long term strategy to make progress toward 
the national visibility protection goal. To fulfill these requirements, 
EPA is authorized to utilize such monitoring techniques that it deems 
appropriate and to promulgate such measures, including control 
strategies, that EPA deems necessary to make reasonable progress toward 
the national visibility goal. 40 CFR 52.26-52.29. As such, if a FLM 
makes a certification of visibility impairment involving a state that 
does not have an approved SIP, EPA determines whether visibility 
impairment in a mandatory Class I Federal area is reasonably 
attributable to an existing stationary facility (defined in footnote 1, 
above). As noted above, EPA acknowledged that the FLMs may certify 
visibility impairment in a Class I Federal area at any time, and 
provided that future certifications of visibility impairment by the 
FLMs would be addressed through the general plan requirements and the 
periodic review requirements set forth in 40 CFR 51.302(c), 51.306(c), 
52.26, and 52.29(c). In the preamble to the visibility FIP, EPA noted 
that it ``may need to reassess the need for BART or other control 
measures'' to remedy future certifications of impairment by the FLM. 52 
FR 7802, 7808 (March 12, 1987). In the preamble to the final rule, EPA 
noted that ``[A]ny certification of impairment made to a State, or to 
EPA in lieu of a State, would then be addressed in the periodic review 
of the visibility SIP or FIP.'' 52 FR 45132, 45136 (November 24, 1987).
    If the state (or EPA) determines that impairment is reasonably 
attributable to an existing stationary facility, then the applicable 
plan's strategy for making progress toward the visibility goal would 
include a determination of BART for that existing stationary facility. 
40 CFR 51.302, 52.26 and 52.29. See also 52 FR 7802, 7808 (March 12, 
1987) and 52 FR 45132, 45136 (November 24, 1987). BART must be 
installed and operated as expeditiously as practicable, but in no case 
later than five years from the date that the state (or EPA) determines 
visibility impairment in a Class I Federal area is reasonably 
attributable to the source(s). (See discussion of BART in section 
III.B., infra.)
4. ``Reasonable Attribution'' Determination for Navajo Generating 
Station
    The threshold for determining whether visibility impairment is 
reasonably attributable to a stationary facility was reviewed by the 
U.S. Court of Appeals for the Ninth Circuit in Central Arizona Water 
Conservation District, et al. v. Environmental Protection Agency, 990 
F.2d 1531, 1541, cert. denied, 114 S. Ct. 94 (1993). In CAWCD, the 
petitioners challenged a final rule by EPA that visibility impairment 
was reasonably attributable to the Navajo Generating Station (NGS). EPA 
had found that visibility impairment in the Grand Canyon National Park 
could in part be reasonably attributed to sulfur dioxide emissions from 
the NGS and required installation and operation of pollution controls 
at the plant as part of the long term strategy for addressing 
visibility impairment. EPA acknowledged that NGS was not the only 
source of visibility impairment at the Grand Canyon. The petitioners 
argued, among other things, that EPA was limited to certain techniques 
for attributing impairment to a particular source, and that EPA 
overestimated the improvement in visibility expected from installing 
and operating controls at NGS. The Ninth Circuit denied the petition 
for review. The Court concluded that the record more than adequately 
supported EPA's conclusion that visibility impairment was attributable 
to NGS. The Court noted that the facts showing the existence of other 
sources of impairment

hardly mean that EPA is without statutory authority to remedy the 
impairment attributable to NGS. Even if the Final Rule addresses 
only a small fraction of the visibility impairment at the Grand 
Canyon, EPA still has the statutory authority to address that 
portion of the visibility impairment problem which is, in fact, 
`reasonably attributable' to NGS. Congress mandated an extremely low 
triggering threshold, requiring the installment of stringent 
emission controls when an individual source `emits any air pollutant 
which may reasonably be anticipated to cause or contribute to any 
impairment of visibility' in a class I Federal area.

CAWCD, 990 F 2d at 1541. The Court further agreed that EPA had broad 
latitude to determine whether visibility impairment is ``reasonably 
attributable'' to a given source, and referred to a report by the 
National Research Council noting that ``Congress has not required 
ironclad scientific certainty establishing the precise relationship 
between a source's emissions and resulting visibility impairment.'' Id.

[[Page 32461]]

B. The Department of the Interior Certification of Visibility 
Impairment

    As discussed above, a Federal Land Manager may at any time certify 
the existence of visibility impairment at a Class I Federal area. On 
November 14, 1985, the Department of the Interior certified to EPA the 
existence of visibility impairment in all Class I Federal areas within 
the Department's jurisdiction in the lower 48 states. On August 19, 
1997, DOI sent a letter to EPA that reaffirmed the Department's 1985 
certification of visibility impairment at the Grand Canyon National 
Park and stated DOI's belief that there is sufficient information 
available to support a ``reasonable attribution'' finding concerning 
the Mohave Generating Station (MGS). The DOI provided, as an attachment 
to its August 1997 letter, a document prepared by the National Park 
Service which summarizes published studies which DOI believes 
demonstrate that emissions from MGS contribute to visibility impairment 
at GCNP. The DOI requested that if EPA agreed with DOI's assessment of 
``reasonable attribution,'' EPA comply with its statutory obligation to 
determine the best available retrofit technology for MGS. The DOI 
recommended that in doing so, EPA discuss the environmental, energy, 
and economic factors relevant to MGS with key interested parties and 
emphasized that the interests of the Navajo and Hopi tribes be fairly 
represented and protected in the decision-making process. Should EPA 
find that the MGS is reasonably anticipated to cause or contribute to 
visibility impairment at the GCNP, it must consider several factors, 
including available technology, costs of compliance, energy impacts, 
and non-air quality environmental impacts in determining appropriate 
pollution control requirements.

C. Mohave Generating Station

    The Mohave Generating Station is a 1580 MW coal-fired power plant 
located in Laughlin, Nevada, approximately 75 miles southwest of the 
Grand Canyon National Park. It was built between 1967 and 1971. It 
currently emits over 40,000 tons of sulfur dioxide (SO2) per 
year. MGS is operated by Southern California Edison, the majority owner 
of the plant. The Los Angeles Department of Water and Power, Nevada 
Power Company, and Salt River Project also own interests in the plant. 
The coal for the plant comes from the Black Mesa Coal Mine on the Hopi 
and Navajo Reservations via a 273-mile coal slurry pipeline. The mine, 
operated by Peabody Western Coal Company, is jointly owned by the 
Navajo Nation and the Hopi Tribe. Groundwater from an aquifer 
underlying the Navajo and Hopi reservations provides the water for the 
slurry pipeline.

II. Information Available for ``Reasonable Attribution'' Analysis

A. Project MOHAVE

    As a result of EPA regulatory action on the Navajo Generating 
Station, described elsewhere in this notice, Congress directed EPA to 
conduct a tracer study to ascertain the extent to which the Mohave 
Generating Station contributes to visibility impairment at the Grand 
Canyon National Park. Congress created this directive through a budget 
line item in EPA's fiscal year 1991 budget. The tracer study was 
developed as a cooperative effort among EPA, the National Park Service, 
and the majority owners and operators of the MGS, Southern California 
Edison Company. This cooperative effort was named Project Measurement 
Of Haze And Visibility Effects, more commonly referred to as Project 
MOHAVE.
    Project MOHAVE was an extensive monitoring, modeling, and data 
assessment project designed to estimate the contributions of the MGS to 
haze at the GCNP. The field study component of the project was 
conducted in 1992 and contained two intensive monitoring periods 
(approximately 30 days in the winter and approximately 50 days in the 
summer). Tracer materials were continuously released from the MGS stack 
during the two intensive periods to enable the tracking of emissions 
specifically from MGS. Tracer, ambient particulate composition and 
SO2 concentrations were measured at about 30 locations in a 
four-state region. Two of these monitoring sites, Hopi Point near the 
main visitor center at the south rim of the canyon and Meadview near 
the far western end of the national park, were used as key receptor 
sites representative of GCNP.
    The process of identifying and quantifying the impact of MGS's 
emissions on visibility in GCNP used two types of assessment 
methodologies. The first method, known as receptor modeling, is an 
empirical assessment of the extensive data collected during the study 
to estimate the presence of pollutants and tracer emitted from MGS, and 
to estimate increases in particulate sulfur and light scattering. The 
advantage of this method is that it provides for modeled predictions to 
be verified with measured data. The disadvantage of this method is that 
measurements can only be taken at monitored locations during a limited 
time period. The second method relies on the application of 
mathematical models that attempt to estimate the transport and 
chemistry of MGS's emissions. The advantage of such models is that they 
can provide predictions at all locations for all times. The 
disadvantage of these models is that they can provide uncertain results 
due to the models' inability to accurately replicate the complex 
atmospheric chemical processes involved in the formation of visibility-
impairing aerosols.
    From the tracer data and the known ratio of tracer to 
SO2 emission rates for MGS, we know that SO2 
emitted by MGS often reaches Meadview in sufficiently high 
concentrations to have the potential to cause impairment. The magnitude 
of the impairment that is attributable to MGS depends on how much of 
the SO2 from the plant is converted to particulate sulfate. 
Sulfate particles in the atmosphere cause light to scatter which 
creates hazy conditions and poor visibility. Conversion of 
SO2 to sulfate occurs by two different mechanisms: dry 
chemistry and wet chemistry. The rate of dry conversion is slow and 
greatest during the daylight hours. Wet chemistry is relatively fast 
but its occurrence is harder to predict since it requires interaction 
of the SO2 emissions with cloud or fog droplets.
    With one exception, the methods used in Project MOHAVE had to 
explicitly determine or use assumed rates of SO2 to sulfate 
conversion for each time period during transport from MGS to GCNP. The 
models, therefore, relied in part on assumptions regarding how quickly 
emissions move through the atmosphere and how emissions interact with 
clouds, and yielded different results in terms of the amount of 
SO2 converted to sulfate, which in turn produced different 
results regarding the magnitude of Mohave's impact on the Grand Canyon.
    The conclusions from the various modelling methods were not always 
consistent as to which time periods during the study were most 
influenced by emissions from MGS. There is no consensus concerning 
which of the methods is more likely to be correct for any particular 
time period. Therefore, EPA intends to use these estimates to define a 
range for long-term and short-term impacts of the plant on visibility 
at GCNP.
    EPA believes that the results of the Project MOHAVE study indicate 
that the Mohave Generating Station contributes to visibility impairment 
at the Grand Canyon National Park. The empirical data from the tracer 
study show that

[[Page 32462]]

emissions from MGS reach the Meadview site at the western end of GCNP 
in sufficient concentrations to, under certain meteorological 
conditions, convert to sulfate and cause visibility impairment. EPA 
notes that the study results show that the Mohave Generating Station is 
not the major cause of visibility impairment at the GCNP. However, the 
study indicates that because of the quantity of SO2 emitted 
from the Mohave Generating Station and its proximity to the Grand 
Canyon, no other single point source is likely to have as great an 
impact on visibility in the Park.
    The final Project MOHAVE report is available on the EPA, Region IX 
Web Page at http://www.epa.gov/region09/air/mohave.html and in Docket 
Number A2-99-01. Project MOHAVE operated under the joint technical and 
program management of the EPA and Southern California Edison Company in 
close partnership with the National Park Service. Numerous other 
organizations contributed to the operations and assessment work of the 
project. Since the end of the field study component of the project, 
data assessment and modeling efforts have been undertaken by the many 
participants and have lead to numerous papers and reports. By design 
these efforts have been the products of their respective authors and 
have not been endorsed as findings of Project MOHAVE.

B. Other Available Information

    There are other studies pertaining to the Mohave Generating 
Station's impact on visibility at the Grand Canyon National Park. In 
its August 1997 letter to EPA reaffirming visibility impairment at the 
Grand Canyon and indicating that Mohave Generating Station is suspected 
of contributing to that impairment, DOI referenced several published 
papers on this topic as well as the 1993 summary of monitoring data 
from the IMPROVE network, the inter-agency visibility monitoring 
system. The papers referenced included ``Comparison of Two Back 
Trajectory Techniques for Source Apportionment'' by Gebhart, Malm, and 
Iyer, June 1993; ``Receptor Model Applied to Patterns in Space (RMAPS) 
Part II--Apportionment of Airborne Particulate Sulfate from Project 
Mohave'' by Henry, 1997; and ``Examining the Relationship Among 
Atmospheric Aerosols and Light Scattering and Extinction in the Grand 
Canyon Area'' by Malm, Molenar, Eldred, and Sisler, August 1996. The 
general 1993 review of IMPROVE monitoring data and trends showed that 
sulfur-containing particles are an important component of the human-
caused visibility impairment at Grand Canyon National Park (20 to 30 
percent on average). The August 1996 paper confirms this by finding 
that sulfur is responsible for approximately 30 percent of visibility 
impairment. Finally, the June 1993 paper, which analyzes data collected 
over a 13-year period, indicates that the majority of impairment at the 
Grand Canyon is due to transport from the southwest. These papers are 
available in Docket Number A2-99-01.

III. Request for Public Comment

    EPA is requesting public comment on two matters. The Agency is 
seeking information that it should consider in determining whether 
visibility impairment at the Grand Canyon National Park is ``reasonably 
attributable'' to emissions from the Mohave Generating Station. EPA is 
also seeking information that it should consider in conducting a ``Best 
Available Retrofit Technology'' analysis, should it find that 
impairment is ``reasonably attributable'' to the MGS.
    Any determination that impairment at the GCNP is ``reasonably 
attributable'' to MGS, and any analysis of BART for the facility would 
occur through a future EPA rulemaking, including an opportunity for the 
public to comment on EPA's proposed actions.

A. ``Reasonable Attribution'' Determination

    In determining whether to propose that visibility impairment at the 
Grand Canyon National Park is ``reasonably attributable'' to the Mohave 
Generating Station, EPA will consider all available information, 
including the results of the Project MOHAVE study and the papers 
referenced in the August 1997 letter from DOI to EPA. With today's 
notice, EPA is soliciting any additional information to be considered 
in assessing the MGS impact on visibility at GCNP. This may be 
additional analyses of Project MOHAVE data, or new information related 
to assessing impacts over other time periods.

B. ``Best Available Retrofit Technology'' Analysis

    ``Best Available Retrofit Technology'' means an emission limitation 
based on the degree of reduction achievable through the application of 
the best system of continuous emission reduction for each pollutant 
which is emitted by an existing stationary facility. The emission 
limitation must be established on a case-by-case basis, taking into 
consideration (1) the technology available, (2) costs of compliance, 
(3) the energy and non-air quality environmental impacts of compliance, 
(4) any pollution control equipment in use or in existence at the 
source, (5) the remaining useful life of the source, and (6) the degree 
of improvement in visibility which may reasonably be anticipated to 
result from the use of such technology. 40 CFR 51.301(c) and 
52.26(b)(2), and CAA section 169A(g)(2), 42 U.S.C. 7491(g)(2). Pursuant 
to section 169A(b) of the Act, 42 U.S.C. 7491(b), and 40 CFR 
51.302(c)(4)(iii), the emission limitation representing BART for fossil 
fuel-fired power plants with a generating capacity in excess of 750 
megawatts (MW) must be determined pursuant to guidelines set forth by 
the Administrator of EPA. The procedures for conducting a BART analysis 
are set forth in ``Guidelines for Determining Best Available Retrofit 
Technology Analysis for Coal Fired Power Plants and Other Stationary 
Facilities' (``BART Guidance''), EPA publication EPA-450-3-8-009b.
    With today's notice, EPA is soliciting information to be considered 
in establishing BART for MGS, should EPA determine that visibility 
impairment at the GCNP is ``reasonably attributable'' to the facility. 
Information that EPA is seeking includes analyses of information 
related to the six factors listed in the paragraph above.

IV. Activities Related to the Mohave Generating Station and 
Visibility at the Grand Canyon National Park

A. Grand Canyon Visibility Transport Commission

    Congress directed EPA to establish the Grand Canyon Visibility 
Transport Commission to assess information pertaining to adverse 
impacts on visibility at the GCNP and to make recommendations to EPA on 
measures that should be taken to remedy such adverse impacts. The 
Commission, which was established in 1991, conducted an extensive 
review of the scientific, technical, and other information with 
assistance from a range of governmental, business, tribal, and 
environmental interests. On June 10, 1996, the Commission issued a 
report to EPA containing its recommendations for protecting and 
improving visibility in Class I areas of the Colorado Plateau, 
including the GCNP. The recommendations covered a wide range of control 
strategy approaches, planning and tracking activities, and technical 
findings. Regarding stationary sources, the Commission recommended that 
EPA establish SO2 emissions targets for the year 2000 and 
the year 2040, with interim targets to ensure steady and

[[Page 32463]]

continuing emission reductions. The Commission also recommended 
development of market-based regulatory programs if emission targets are 
not met. While the Commission report did not make any specific 
recommendation regarding emission reductions from any specific 
stationary source, such as the Mohave Generating Station, it did 
strongly encourage EPA to complete the Project MOHAVE source 
attribution study and to take action consistent with the results of 
that study within twelve months of its completion.

B. Public Meeting

    The EPA has been working in close partnership with the Secretary's 
Office of the Department of the Interior and the National Park Service 
Air Resources Division to address issues concerning the Mohave 
Generating Station. During the past year and a half, EPA and DOI have 
met with various parties with an interest in the future of the Mohave 
Generating Station. On January 8 and 9, 1998, EPA and DOI held a public 
meeting in Las Vegas, Nevada to present information and seek input on 
the issues, interests, and concerns related to the Mohave Generating 
Station and visibility impairment at the Grand Canyon National Park. 
Several informational panels outlined the issues, provided background 
on visibility science and EPA's visibility regulations, discussed 
issues associated with utility restructuring that affect the plant, and 
outlined options for reducing emissions at the plant.
    Approximately 90 people representing a variety of affected groups 
attended the meeting. Representatives from local governments and 
businesses stressed the importance of MGS to the local economy and 
characterized MGS as a good corporate citizen that supported schools 
and civic projects. One private citizen expressed concern about the 
health effects of emissions from the plant, noting that a plume of 
smoke was always visible from the plant. Speakers for environmental 
groups stated that MGS is a significant contributor to haze at the 
Grand Canyon National Park, emits pollutants at a higher level than 
other power plants, and is at a competitive advantage to other plants 
that have installed pollution controls. The environmental groups 
believe that there is enough information available currently to show 
that MGS is affecting visibility at the Grand Canyon National Park and 
that EPA should act immediately to require pollution controls. The 
Navajo Nation expressed concerns about air and water quality but 
highlighted the importance of MGS to the Navajo economy, which depends 
significantly on revenues from coal sales to the plant. Southern 
California Edison stated that it wants to protect the environment while 
maintaining the economic viability of the plant. SCE stated that at the 
current market price for electricity, the cost of installing control 
equipment at the plant would make the plant unprofitable. Union 
representatives, MGS employees, and companies that provide raw 
materials to MGS highlighted their reliance on MGS and emphasized that 
continued operation of the plant is important to state, local, and 
tribal economies and living standards.
    In addition to the comments made at the public meeting in Las 
Vegas, EPA has received hundreds of letters from people expressing 
concern about visibility impairment at the Grand Canyon and urging EPA 
to require installation of pollution controls at the Mohave Generating 
Station.

C. Grand Canyon Trust/Sierra Club Lawsuit

    On February 19, 1998, Grand Canyon Trust (GCT) filed a citizen suit 
in the federal district court for the District of Nevada against the 
owners of the Mohave Generating Station. GCT alleged that the defendant 
had violated several SIP provisions that apply to the Mohave Generating 
Station. GCT included allegations that the Mohave Generating Station 
had exceeded emission limits in the Nevada and Clark County SIPs for 
opacity and sulfur dioxide, and had failed to conduct necessary 
reporting. Sierra Club and the National Parks and Conservation 
Association subsequently joined GCT as plaintiffs in the citizen suit. 
The defendants have filed a motion to dismiss the suit and a motion for 
partial summary judgement. The plaintiffs have filed an opposition to 
the motion to dismiss and a motion for partial summary judgment. These 
motions are currently pending before the court.

D. Environmental Defense Fund Letter

    The Environmental Defense Fund (EDF) submitted a letter to the 
Regional Administrator of EPA Region IX in November 1998 noting its 
concern over EPA's failure to conduct a review of the visibility 
protection plan for the state of Nevada. As part of the long term 
strategy to address visibility protection, EPA is required to conduct a 
review of the visibility protection plan every three years to determine 
whether the plan is sufficient or if additional measures are necessary 
for visibility protection. 40 CFR 52.29(c)(4). (Because the state of 
Nevada does not have an approved SIP for visibility, EPA is required to 
assume responsibility for visibility protection until such time as the 
State submits, and EPA approves, a SIP that adequately provides for 
visibility protection.) Pursuant to 40 CFR 52.29, EPA must include in 
its triennial report an assessment of the progress made in remedying 
existing impairment, changes in visibility since the last report, 
whether additional measures are necessary to assure reasonable progress 
toward the national visibility goal and any progress achieved in 
implementing BART. EDF notes that EPA has not updated the visibility 
protection plan or conducted any of the required reviews, even though 
the Department of the Interior has notified EPA of visibility 
impairment at the Grand Canyon National Park and has submitted 
information indicating that such impairment is attributable to 
emissions from the Mohave Generating Station. EDF further refers to 
studies that have been conducted (including Project MOHAVE) which EDF 
believes indicate that emissions from the Mohave Generating Station 
contribute to visibility impairment. On April 20, 1999, EDF sent EPA 
notice of its intent to sue the Agency, pursuant to section 304(b)(1) 
of the Act, 42 U.S.C. 7604(b)(1), and 40 CFR part 54. EDF's notice of 
intent to sue made the same claims as contained in its November 1998 
letter to EPA.

E. Southern California Edison Proposal

    On December 11, 1998, Southern California Edison and the other 
owners of the Mohave Generating Station announced that by 2008, they 
would either install emission control equipment at the plant or shut 
the plant down. The control equipment would include sulfur-dioxide 
scrubbers and bag houses, devices designed to reduce particulate matter 
emissions. The MGS owners stated that installations could begin by 2005 
and that work would be completed no later than 2008. The owners noted 
that the plant must be able to operate economically with additional 
emission control devices; otherwise the plant would not operate beyond 
2008. The announcement indicated that the MGS owners would participate 
in collaborative discussions with interest groups, including the Hopi 
tribe, the Navajo Nation, environmental organizations, communities near 
the plant, plant employees, and state and federal agencies to ``speed 
resolution of key environmental issues regarding the Mohave plant.''

[[Page 32464]]

V. Administrative Requirements

A. Executive Order 12866

    Under Executive Order 12866, 58 FR 51735 (October 4, 1993), the 
Agency must determine whether the regulatory action is ``significant'' 
and therefore subject to Office of Management and Budget (OMB) review 
and the requirements of the Executive Order. The Order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or state, local, or tribal governments or 
communities;
    (2) create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    Due to potential policy issues this action is considered a 
significant regulatory action and therefore was reviewed by OMB. 
Changes made in response to OMB suggestions or recommendations have 
been documented in the public record.

B. Regulatory Flexibility Act

    Under the Regulatory Flexibility Act (RFA), 5 U.S.C. 601 et. seq., 
EPA must prepare a regulatory flexibility analysis assessing the impact 
of any rule on small entities unless the Agency certifies that the rule 
will not have a significant economic impact on a substantial number of 
small entities. 5 U.S.C. 603, 604 and 605(b). Small entities include 
small businesses, small not-for-profit enterprises, and government 
entities with jurisdiction over populations of less than 50,000. This 
advance notice of proposed rulemaking will not have a significant 
impact on a substantial number of small entities because it will not 
create any new requirements for any entity. The notice merely presents 
background information and requests input from the public. Therefore, I 
certify that this action will not have a significant economic impact on 
a substantial number of small entities. Therefore, this advance notice 
of proposed rulemaking does not require a regulatory flexibility 
analysis.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Sulfur oxides.

    Dated: June 11, 1999.
Carol M. Browner,
Administrator.
[FR Doc. 99-15435 Filed 6-16-99; 8:45 am]
BILLING CODE 6560-50-P