[Federal Register Volume 59, Number 164 (Thursday, August 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-20810]
[[Page Unknown]]
[Federal Register: August 25, 1994]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[ID2-1-5552a; FRL-5012-8]
Approval and Promulgation of State Implementation Plans: Idaho
AGENCY: Environmental Protection Agency.
ACTION: Final rule.
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SUMMARY: Environmental Protection Agency (EPA) approves the State
Implementation Plan (SIP) submitted by the State of Idaho for the
purpose of bringing about the attainment of the national ambient air
quality standards (NAAQS) for particulate matter with an aerodynamic
diameter less than or equal to a nominal 10 micrometers (PM-10). The
implementation plan was submitted by the State and satisfied certain
Federal requirements for an acceptable moderate nonattainment area PM-
10 SIP for Pinehurst, Idaho.
DATES: This final rule will be effective on October 24, 1994 unless
adverse or critical comments are received by September 26, 1994. If the
effective date is delayed, timely notice will be published in the
Federal Register.
ADDRESSES: Written comments should be addressed to: Montel Livingston,
Environmental Protection Agency, 1200 Sixth Avenue, AT-082, Seattle,
Washington 98101.
Documents which are incorporated by reference are available for
inspection during normal business hours at the Air and Radiation Docket
and Information Center, Environmental Protection Agency, 401 M Street
SW., Washington, DC 20460. Copies of material submitted to EPA may be
examined during normal business hours at the following locations:
Environmental Protection Agency, 1200 Sixth Avenue, Seattle, WA 98101,
and the State of Idaho Division of Environmental Quality, 1410 N.
Hilton, Boise, ID 83720.
FOR FURTHER INFORMATION CONTACT: Stephen Fry, Environmental Protection
Agency, 1200 Sixth Avenue, AT-082, Seattle, Washington 98101, (206)
553-2575.
SUPPLEMENTARY INFORMATION:
I. Background
The Shoshone County, Pinehurst, Idaho area was designated
nonattainment for PM-10 and classified as moderate under sections
107(d)(4)(B) and 188(a) of the Clean Air Act, upon enactment of the
Clean Air Act Amendments of 1990\1\ (see 56 FR 56694 (November 6, 1991)
and 40 CFR 81.313 (codified air quality designation for the Pinehurst
area)). The air quality planning requirements for moderate PM-10
nonattainment areas are set out in subparts 1 and 4 of title I of the
Act.\2\ EPA has issued a ``General Preamble'' describing EPA's
preliminary views on how EPA intends to review SIP's and SIP revisions
submitted under title I of the Act, including those State submittals
containing moderate PM-10 nonattainment area SIP requirements (see
generally 57 FR 13498 (April 16, 1992) and 57 FR 18070 (April 28,
1992)). Because EPA is describing its interpretations here only in
broad terms, the reader should refer to the General Preamble for a more
detailed discussion of the interpretations of title I advanced in this
proposal and the supporting rationale. In this rulemaking action on the
State of Idaho's moderate PM-10 SIP for the Pinehurst nonattainment
area, EPA is applying its interpretations taking into consideration the
specific factual issues presented. Additional information supporting
EPA's action on this particular area is available for inspection at the
address indicated above.
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\1\The 1990 Amendments to the Clean Air Act made significant
changes to the Act. See Public Law No. 101-549, 104 Stat. 2399.
References herein are to the Clean Air Act, as amended (``the Act''
or ``CAA''). The Clean Air Act is codified, as amended, in the U.S.
Code at 42 U.S.C. 7401, et seq.
\2\Subpart 1 contains provisions applicable to nonattainment
areas generally and subpart 4 contains provisions specifically
applicable to PM-10 nonattainment areas. At times, subpart 1 and
subpart 4 overlap or conflict. EPA has attempted to clarify the
relationship among these provisions in the ``General Preamble'' and,
as appropriate, in today's notice and supporting information.
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Those states containing initial moderate PM-10 nonattainment areas
(those areas designated nonattainment under section 107(d)(4)(B)) were
required to submit, among other things, the following provisions by
November 15, 1991:
1. Provisions to assure that reasonably available control measures
(RACM) (including such reductions in emissions from existing sources in
the area as may be obtained through the adoption, at a minimum, of
reasonably available control technology (RACT)) shall be implemented no
later than December 10, 1993;
2. Either a demonstration (including air quality modeling) that the
plan will provide for attainment as expeditiously as practicable but no
later than December 31, 1994, or a demonstration that attainment by
that date is impracticable;
3. Quantitative milestones which are to be achieved every three
years and which demonstrate reasonable further progress (RFP) toward
attainment by December 31, 1994; and
4. Provisions to assure that the control requirements applicable to
major stationary sources of PM-10 also apply to major stationary
sources of PM-10 precursors except where the Administrator determines
that such sources do not contribute significantly to PM-10 levels which
exceed the NAAQS in the area (see sections 172(c), 188, and 189 of the
Act).
States with initial moderate PM-10 nonattainment areas were
required to submit a permit program for the construction and operation
of new and modified major stationary sources of PM-10 by June 30, 1992
(see section 189(a) of the CAA). This permit program element, also
known as the New Source Review (NSR) program, was submitted by the
State of Idaho on May 17, 1994. EPA notified Idaho in a June 10, 1994
letter to the Administrator of the Idaho Division of Environmental
Quality that the NSR program submittal was complete. EPA is currently
in the process of reviewing the NSR program to determine if the program
meets the requirements of the CAA. EPA intends to take action on
Idaho's NSR program when EPA has completed its review.
In addition, states containing initial moderate PM-10 nonattainment
areas were required to submit contingency measures by November 15,
1993, which become effective without further action by the State or EPA
upon a determination by EPA that the area has failed to achieve RFP or
to attain the PM-10 NAAQS by the applicable statutory deadline (see
section 172(c)(9) and 57 FR 13543-13544). Contingency measures for the
Pinehurst PM-10 nonattainment area have not yet been submitted by IDEQ.
A findings letter, dated January 13, 1994, was mailed to the Governor
of Idaho which informed him that the State had failed to make the
required PM-10 contingency measures submittal for Pinehurst. The State
has until July 13, 1995 to correct this deficiency for Pinehurst, or it
will face Federal highway or offset sanctions (see section 179 of the
CAA and 58 FR 51270 (October 1, 1993)).
EPA intends to take action on the contingency measures for the
Pinehurst PM-10 nonattainment area when this requirement is submitted
or intends to impose sanctions in the event this deficiency is not
corrected.
II. This Action
Section 110(k) of the Act sets out provisions governing EPA's
review of SIP submittal (see 57 FR 13565-13566). In this action, EPA is
granting approval of the plan revision submitted to EPA on April 14,
1992. EPA has determined that the submittal meets the applicable
requirements of the Act, with respect to moderate area PM-10 submittal.
Analysis of State Submission
1. Procedural Background
The Act requires states to observe certain procedural requirements
in developing implementation plans and plan revisions for submission to
EPA. Section 110(a)(2) of the Act provides that each implementation
plan submitted by a State must be adopted after reasonable notice and
public hearing.\3\ Section 110(l) of the Act similarly provides that
each revision to an implementation plan submitted by a State under the
Act must be adopted by such State after reasonable notice and public
hearing.
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\3\Also Section 172(c)(7) of the Act requires that plan
provisions for nonattainment areas meet the applicable provisions of
section 110(a)(2).
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EPA has also determined whether a submittal is complete and
therefore warrants further EPA review and action (see section 110(k)(1)
and 57 FR 13565). EPA's completeness criteria for SIP submittals are
set out at 40 CFR part 51, appendix V. EPA attempts to make
completeness determinations within 60 days of receiving a submission.
However, a submittal is deemed complete by operation of law if a
completeness determination is not made by EPA six months after receipt
of the submission.
The Idaho Division of Environmental Quality (IDEQ) held a public
hearing on the Pinehurst PM-10 plan on January 22, 1992 in Pinehurst
and, after IDEQ reviewed the oral testimony, the plan was adopted by
the IDEQ Administrator on April 7, 1992. The submitted plan was
received by EPA on April 14, 1992 as a revision to the SIP.
The SIP revision was reviewed by EPA to determine completeness
shortly after its submittal, in accordance with the completeness
criteria set out at 40 CFR part 51, appendix V. A letter dated June 8,
1992 was forwarded to the Administrator of IDEQ indicating the
completeness of the submittal and the next steps to be taken in the
review process. In this action EPA is approving the State of Idaho's
PM-10 SIP submittal for the Pinehurst PM-10 nonattainment area.
Since the Pinehurst PM-10 SIP requirements due on November 15, 1991
were not submitted by that date as required by section 189(a)(2)(A) of
the CAA, EPA made a finding, pursuant to section 179 of the Act, that
the State failed to submit the SIP revision and notified the Governor
in a letter dated December 18, 1991 (see 57 FR 19906 (May 8, 1992)).
EPA's June 8, 1992 determination that the State had made a complete
submittal corrected the State's failure to submit the PM-10 SIP
requirements for Pinehurst due on November 15, 1991 and, therefore,
terminated the 18-month sanctions clock for that deficiency under
section 179 of the CAA.
2. Accurate Emissions Inventory
Section 172(c)(3) of the Act requires that nonattainment plan
provisions include a comprehensive, accurate, current inventory of
actual emissions from all sources of relevant pollutants in the
nonattainment area. The emissions inventory should also include a
comprehensive, accurate, and current inventory of allowable emissions
in the area (see section 110(a)(2)(K) of the CAA). Because the
submission of such inventories is necessary to an area's attainment
demonstration (or demonstration that the area cannot practicably
attain), the emissions inventories must be received with the submission
(see 57 FR 13539).
The base year emission inventory (1988) developed for the Pinehurst
nonattainment area identified the major sources of PM-10 concentrations
during 24-hour worst case winter days as residential wood combustion
(59%), fugitive dust (38%) and other sources (3%). Annual emissions for
1988 were residential wood combustion (41%), fugitive dust (38%),
building construction (18%) and other sources (3%).
EPA is approving the emissions inventory because it generally
appears to be accurate and comprehensive, and provides a sufficient
basis for determining the adequacy of the attainment demonstration for
this area consistent with the requirements of sections 172(c)(3) and
110(a)(2)(K) of the Clean Air Act.\4\ For further details see the
Technical Support Document (TSD).
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\4\The EPA issued guidance on PM-10 emissions inventories prior
to the enactment of the Clean Air Act Amendments in the form of the
1987 PM-10 SIP Development Guideline. The guidance provided in this
document appears to be consistent with the amended Act; therefore,
EPA may continue to rely on this guidance (see section 193 of the
CAA).
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3. RACM (Including RACT)
As noted, the initial moderate PM-10 nonattainment areas must
submit provisions to assure that RACM (including RACT) were implemented
no later than December 10, 1993 (see sections 172(c)(1) and
189(a)(1)(C)). The General Preamble contains a detailed discussion of
EPA's interpretation of the RACM (including RACT) requirement (see 57
FR 13539-13545 and 13560-13561).
a. Residential Wood Combustion Program. Attainment of the 24-hour
and annual standards is based on control strategies designed to reduce
wood smoke. Attainment is demonstrated through the establishment of a
voluntary residential wood combustion curtailment program, wood stove
replacement program and home weatherization program. The specific
control measures are supported and enhanced through an aggressive air
pollution public awareness program. More details regarding these
control measures are as follows:
(1) Episodic Wood Burning Curtailment Program. The IDEQ is in
charge of declaring episodic voluntary wood burning curtailments in the
Pinehurst nonattainment area. A voluntary burn ban is declared when 24-
hour PM-10 levels in the nonattainment area, as estimated by
nephelometer, are measured to exceed 100 g/m3. To keep
the public informed regarding particulate air quality levels, a 24-hour
PM-10 prediction is made for the Pinehurst/Silver Valley area after an
IDEQ meteorologist calculates lower atmospheric stability and evaluates
nephelometer, upper air temperature sounding, snow cover, surface
temperature, delta temperature, wind speed, cloud cover, National
Weather Service and occasionally commercial weather service data.
Wood burning advisories are made in conjunction with the air
quality report and are issued weekdays and, as necessary on weekends
and holidays, by 9 a.m., from November 1 through the end of February.
The advisory is recorded on a telephone answering machine for both the
public and media. When a voluntary wood burning curtailment is
declared, the IDEQ directly contacts the media and conducts radio and
television interviews to publicize the existence of a burn ban.
Voluntary curtailment declarations are also carried routinely by the
local radio station and newspaper.
IDEQ requests a 25 percent emission reduction credit for its
voluntary curtailment program in the Pinehurst nonattainment area
during 24-hour worst case periods. The 25 percent credit is greater
than the ten percent generally suggested by EPA for voluntary
curtailment programs. The recommended ten percent credit is viewed by
EPA as a ``starting point in assessing the effectiveness of residential
wood combustion control programs.'' However, final judgement of the
amount of credit to be granted is determined by EPA's regional offices
based on the program features outlined in EPA's Guidance Document for
Residential Wood Combustion Emission Control Measures, September 1989,
(EPA-450/2-89-015). More than ten percent credit may be granted based
on the program's effectiveness.
IDEQ cites residential wood heating surveys that were conducted in
the Ada County/Boise PM-10 nonattainment area, that indicate a 43
percent effectiveness rate for the voluntary curtailment program in
that part of Idaho. The State points out in the Pinehurst SIP that the
Pinehurst City Council adopted a resolution (on November 11, 1991)
supporting the curtailment program and requesting all Pinehurst
citizens, except those who must rely on wood burning as their sole
source of heat, to not burn wood during a curtailment episode.
Therefore, the features of the Pinehurst curtailment program, the
effectiveness data obtained from Ada County/Boise coupled with the
demonstrated local support for the curtailment program by the leaders
of Pinehurst is the basis for IDEQ's 25 percent emission reduction
claim. According to IDEQ calculations this 25 percent reduction is
equivalent to a PM-10 emission reduction of 51.3 lbs/day and a 24-hour
PM-10 ambient reduction of 20 g/m3.
Based upon the surveys conducted in Ada County/Boise, the support
by Pinehurst City officials and the recent success during the 1992-1993
and 1993-1994 wood burning seasons in preventing PM-10 concentrations
from exceeding the 24-hour NAAQS, EPA is satisfied that at least a 25
percent emission reduction is occurring when voluntary episodic wood
burning curtailments are declared in Pinehurst. Therefore, EPA is
accepting the 25 percent credit claimed for this control measure.
Further description of this program and justification for EPA's action
is set out in the TSD, contained in the public record corresponding
with this action.
(2) Public Awareness Program. The wood smoke public awareness
program for the Pinehurst/Silver Valley area plays a critical role in
ensuring that the residential wood combustion program is successful.
Public awareness of the problems associated with wood smoke has a
significant effect on how well the different components of the wood
smoke control program are accepted. IDEQ has utilized the following
methods to promote public awareness about the wood smoke problem in
Pinehurst: education brochures for each household, utility bill
inserts, newspaper articles--public service announcements (PSA's),
educational materials for elementary schools, surveys to determine the
level of awareness and response to programs, radio interviews, radio
PSA's, outreach to wood stove dealers and wood/pellet fuel outlets, and
Speakers Bureau through service clubs and community meetings. IDEQ's
well-established public awareness program was enhanced in 1991, when
$14,550 was awarded by the Pacific Northwest and Alaska Bioenergy
Program to provide wood energy education in Idaho's Silver Valley
(which includes Pinehurst). For the 1993-1994 and 1994-1995 residential
heating seasons, a wood stove advocate has been hired by IDEQ to serve
as an information outlet regarding wood stove issues and also track the
progress of reducing wood stove emissions.
IDEQ is claiming a five percent credit for the Pinehurst wood smoke
public awareness program. This credit is based upon the increased
effectiveness of the public awareness program since 1991, the fact that
Pinehurst is a small town (population 1,722 in 1990)--which makes it
relatively easy to keep in contact with the citizens, and the fact that
IDEQ has hired a Pinehurst wood stove advocate to work on increasing
the public's awareness of the availability of cleaner-burning
residential heating devices.
Considering IDEQ's aforementioned reasons for claiming a five
percent emission reduction credit (which equals a PM-10 emission
reduction of 10.8 lbs/day, and a 24-hour PM-10 ambient reduction of 4
g/m3), EPA is accepting the five percent credit requested
by the IDEQ.
(3) Uncertified Wood Stove Change-out Program. IDEQ is in the
process of replacing 90 uncertified wood stoves in the Pinehurst
nonattainment area with cleaner heating devices. The uncertified wood
stoves are replaced as part of a combined Federal assistance grant, and
State and local loan program. Ninety grants ranging from $500-$1,750
each will be offered to the residents of Pinehurst as financial
incentive to replace their uncertified stoves with natural gas
furnaces, pellet stoves or phase II wood stoves. In addition, 50 of
these participants will be offered low interest loans, up to a maximum
amount of $1,500 per homeowner, using Idaho Department of Water
Resources (IDWR) funds. These loans will cover the additional costs of
upgrading the qualifying resident's heating system, including the cost
of installation. IDWR will allow the loans to be paid back over a five-
year period. The combined grant and loan program will be administered
by the Northern Idaho Community Action Agency (NICAA).
It is estimated by IDEQ that the combined grant/loan program will
replace 90 uncertified wood stoves with 40 natural gas furnaces, 25
pellet stoves and 25 phase II wood stoves. This change is projected to
result in a PM-10 emission reduction of 43.4 lbs/day (which equals a 17
g/m3 24-hour PM-10 reduction) in the Pinehurst
nonattainment area (based upon a 100%, 95% and 55% emission reduction
credits for replacing uncertified wood stoves with natural gas
furnaces, pellet stoves and phase II wood stoves, respectively; a 0.56
lbs/day PM-10 emission rate for a uncertified wood stove in Pinehurst;
and the determination that a PM-10 emission rate of 393 lbs/day equals
a 24-hour ambient PM-10 concentration of 150 g/m3 at
Pinehurst).
Thus, IDEQ is estimating that the wood stove change-out program
will reduce PM-10 emissions from residential wood combustion devices in
Pinehurst by 16.5 percent (or 43.4 lbs of PM-10 reduced/day divided by
263.8 lbs of PM-10 emitted on the worst case day in 1994). EPA believes
that the program will reduce PM-10 emissions in the Pinehurst
nonattainment area because the program is receiving broad based support
and has secure funding sources. Therefore, EPA is accepting the 16.5
percent PM-10 emission reduction credit that IDEQ claims will result
from implementation of the wood stove change-out program.
(4) Home Weatherization Program. Wood stove emissions can be
reduced slightly through comprehensive weatherization programs that
result in a reduction of the amount of fuel utilized. The Idaho
Economic Opportunity Office offers free weatherization assistance to
low income families. This assistance takes the form of an energy audit,
which may result in insulation, weather stripping and heating system
improvements.
Home weatherization improvements will be applied to all 90
households in which wood stove change-outs occur, using loans and grant
money from Idaho Department of Water Resources, Farmers Home
Administration, Washington Water Power and North Idaho Community Action
Agency's Weatherization Division. At least 30 other homes will be
targeted for weatherization improvements.
EPA's Guidance Document for Residential Wood Combustion Emission
Control Measures, September 1989, generally recommends less than a five
percent credit for home weatherization programs. However, IDEQ is
claiming an eight percent credit for the Pinehurst home weatherization
program for the following three reasons: a. Pinehurst has a higher than
normal percentage of older, uninsulated homes; b. Shoshone County,
which contains Pinehurst, has a high percentage of low income
households, who in the past were unable to afford weatherization; and
c. Pinehurst's cold winter climate results in a high number of heating
degree days, which enables a home weatherization program to have more
impact than it would in an area that possesses a warmer winter climate.
The eight percent reduction claimed from the program is only
equivalent to a PM-10 decrease of 3.5 lbs/day (which equals a daily
ambient PM-10 reduction of 1 g/m3). Therefore, this
program will have only a slight impact on PM-10 levels during worst
case days. Nonetheless, in light of IDEQ's reasoning that homes in
Pinehurst are in need of weatherization, and that weatherizing 120
homes will result in lower fuel consumption and correspondingly less
PM-10 emissions in the Pinehurst nonattainment area, EPA is accepting
the eight percent credit claimed by IDEQ.
b. Other Sources. RACM (including RACT) does not require the
imposition of controls on emissions from sources that are insignificant
(i.e. de minimis) and does not require the implementation of all
available control measures where an area demonstrates timely attainment
and the implementation of additional controls would not expedite
attainment (see 57 FR 13540-44).
IDEQ has determined, through its emission inventory analysis of the
nonattainment area, that road dust contributed 38 percent of the PM-10
concentration on the worst case days in base year 1988. IDEQ
demonstrated timely attainment of the 24-hour PM-10 NAAQS by
controlling wood smoke. Therefore, RACM does not require road dust
control measures. Furthermore, RACM does not require the implementation
of controls for prescribed silvicultural and agricultural burning for
the Pinehurst nonattainment area, because the area is not significantly
impacted by those activities on worst case days, according to the
emission inventory analysis.
Similarly, RACT does not require the implementation of control
technology for sources of PM-10 in the nonattainment area, because the
area is primarily characterized by residential and commercial uses
which are not subject to RACT requirements. There are no major
stationary sources operating in the Pinehurst PM-10 nonattainment area.
A more detailed discussion of the control measures contained in the
SIP and an explanation as to why certain available control measures
were not implemented, can be found in IDEQ's submittal and in the TSD.
EPA has reviewed IDEQ's submittal and associated documentation and
concluded that they adequately justify the control measures to be
implemented. The implementation of the Pinehurst, Idaho PM-10
nonattainment plan control strategy will result in the attainment of
the PM-10 NAAQS as expeditiously as practicable--by December 31, 1994.
By this notice, EPA is approving IDEQ's control strategy as satisfying
the RACM (including RACT) requirement.
4. Demonstration
Moderate PM-10 nonattainment areas must submit a demonstration
(including air quality modeling) showing that the plan will provide for
attainment as expeditiously as practicable but no later than December
31, 1994 (see section 189(a)(1)(B) of the Act). The General Preamble
sets out EPA's guidance on the use of modeling for moderate area
attainment demonstrations (57 FR 13539). Alternatively, the State must
show attainment by December 31, 1994, is impracticable. The 24-hour PM-
10 NAAQS is 150 micrograms/cubic meter (g/m3), and the
standard is attained when the expected number of days per calendar year
with a 24-hour average concentration above 150 g/m3 is
equal to or less than one (see 40 CFR 50.6). The annual PM-10 NAAQS is
50 g/m3, and the standard is attained when the expected
annual arithmetic mean concentration is less than or equal to 50
g/m3 (id.).
IDEQ utilized an attainment demonstration for Pinehurst based upon
proportional rollback modeling supported by a complete emission
inventory, receptor modeling and WYNDvalley, a non-guideline dispersion
model.
The receptor modeling consisted of using the Chemical Mass Balance
(CMB) version 7.0 air quality model to analyze for days during 1988-
1990 when 24-hour PM-10 concentrations were either elevated or exceeded
the NAAQS. CMB results from ten PM-10 filters showed that on the
average residential wood smoke and fugitive dust were responsible for
77 and 18 percent, respectively, of the PM-10 on high concentration
days. The CMB percentages for residential wood smoke and fugitive dust
are greater and lower, respectively, than those that were determined
from the emission inventory, but the CMB analysis still confirms that
residential wood combustion is the major source of PM-10 on worst case
days in the Pinehurst nonattainment area. Therefore, these results
support IDEQ's reliance on wood smoke control strategies to attain the
PM-10 standard.
The IDEQ used version 3.06 of the WYNDvalley dispersion model to
simulate PM-10 concentrations in Pinehurst during a wintertime
stagnation episode. WYNDvalley was chosen because of the model's
ability to handle both the light wind conditions and complex terrain
that significantly help trap PM-10 air pollution in the Pinehurst PM-10
nonattainment area. Also, the WYNDvalley dispersion model was used
because Pinehurst is dominated by area sources (wood smoke and fugitive
road dust) and lacks any major point source impacts. The modeled
stagnation event began on January 20, 1988 and continued through
January 30, 1988. Pinehurst's design value exceedance of 183
g/m3 was measured on January 28, during this stagnant
period. The WYNDvalley model showed that the maximum PM-10 values
occurred at or near the Pinehurst school, agreeing with results found
in the January-March 1989 CMB/saturation study. Therefore, the model
helped verify that the Pinehurst PM-10 monitor is situated in the area
of maximum PM-10 impact.
The attainment demonstration indicates that Pinehurst will attain
the 24-hour PM-10 NAAQS by December 31, 1994, with the maximum 24-hour
concentration predicted to be 143 g/m3 (which is the
result of the proposed control measures reducing the projected 1994
maximum PM-10 emissions from 484.8 to 375.9 lbs/day).
According to EPA's review, which identified incomplete quarterly
data in 1986 and corrected for the use of non-reference PM-10 data in
1986 and 1987 (i.e. Hi-Vol SA321A gravimetric PM-10 sampler), Pinehurst
has never violated the annual arithmetic mean PM-10 standard. The
highest valid three-year annual average at Pinehurst is 46 g/
m3, during 1987-1989, while the lowest three-year average is 36
g/m3, during 1990-1992. Therefore, IDEQ and EPA believe
that because the annual PM-10 standard has never been violated at
Pinehurst, and the 24-hour PM-10 controls have helped reduce annual
concentrations (as evidenced in the downward trend in the annual
average concentrations), it is reasonable to predict that the area will
continue to meet the annual standard and the standard will not be
violated in 1994.
EPA is finding that the modeling analysis is adequate to
demonstrate timely attainment of the PM-10 NAAQS in Pinehurst. The
control strategies used to achieve attainment are summarized in the
section titled ``RACM (including RACT).'' A more detailed description
of the attainment demonstration is contained in the TSD accompanying
this notice.
It should be noted that the 1997 maintenance demonstration,
supplied by IDEQ, shows that Pinehurst will remain in attainment for
both the 24-hour and annual PM-10 NAAQS through 1997. According to
IDEQ's calculations, which were partially based on a 1994 Washington
Water Power residential heating survey for the Pinehurst area, the
maximum 24-hour PM-10 concentration in 1997 will be 127 g/
m3. This 1997 24-hour value is equivalent to a PM-10 emission rate
of 332 lbs/day. Furthermore, the annual arithmetic standard will be
maintained from 1994-2000, with the maximum annual average value of
47.2 g/m3 (occurring in the year 2000). This
aforementioned concentration is equivalent to a PM-10 emission rate of
47.0 tons/year. This 1997 maintenance demonstration satisfies part of
the quantitative milestones/reasonable further progress requirement
(see CAA section 189(c)).
5. Quantitative Milestones and Reasonable Further Progress (RFP)
The PM-10 nonattainment area plan revisions demonstrating
attainment must contain quantitative milestones which are to be
achieved every three years until the area is redesignated attainment
and which demonstrate RFP, as defined in section 171(1), toward
attainment by December 31, 1994 (see section 189(c) of the CAA).
While section 189(c) plainly provides that quantitative milestones
are to be achieved until an area is redesignated attainment, it is
silent in indicating the starting point for counting the first three-
year period or how many milestones must be initially addressed. In the
General Preamble, EPA addressed the statutory gap in the starting point
for counting the three-year milestones, indicating that it would begin
from the due date for the applicable implementation plan revision
containing the control measures for the area (i.e., November 15, 1991
for initial moderate PM-10 nonattainment areas) (see 57 FR 13539).
As to the number of milestones, EPA believes that at least two
milestones must be initially addressed. Thus, submittal to address the
SIP revisions due on November 15, 1991 for the initial moderate PM-10
nonattainment areas must demonstrate that two milestones will be
achieved (First milestone: November 15, 1991 through November 15, 1994;
Second milestone: November 15, 1994 through November 15, 1997).
For the initial PM-10 nonattainment areas that demonstrate
attainment, the emissions reduction progress made between the SIP
submittal (due date of November 15, 1991) and the attainment date of
December 31, 1994 (46 days beyond the November 15, 1994 milestone date)
will satisfy the first quantitative milestone. The de minimis timing
differential makes it administratively impracticable to require
separate milestone and attainment demonstrations (see 57 FR 13539). For
such areas that demonstrate timely attainment of the PM-10 NAAQS, the
second milestone should, at a minimum, provide for continued
maintenance of the standards.\5\
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\5\ Section 189(c) of the Act provides that quantitative
milestones are to be achieved ``until the area is redesignated
attainment.'' However, this endpoint for quantitative milestones is
speculative because redesignation of an area as attainment is
contingent upon several factors and future events. Therefore, EPA
believes it is reasonable for States to initially address at least
the first two milestones. Addressing two milestones will ensure that
the State continues to maintain the NAAQS beyond the attainment date
for at least some period during which an area could be redesignated
attainment. However, in all instances, additional milestones must be
addressed if an area is not redesignated attainment.
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This SIP demonstrates attainment by December 31, 1994 and
maintenance through December 31, 1997, satisfying two milestones.
Therefore, the submittal satisfies the quantitative milestones
currently due. Accordingly, EPA is approving the SIP for Pinehurst
relative to the quantitative milestone requirement.
Finally, once a milestone has passed, the State will have to
demonstrate that the milestone was, in fact, achieved for the Pinehurst
area as provided in section 189(c)(2) of the Act.
6. PM-10 Precursors
The control requirements which are applicable to major stationary
sources of PM-10, also apply to major stationary sources of PM-10
precursors unless EPA determines such sources do not contribute
significantly to PM-10 levels in excess of the NAAQS in that area (see
section 189(e) of the Act). The General Preamble contains guidance
addressing how EPA intends to implement section 189(e) (see 57 FR
13539-13540 and 13541-13542).
The filter analyses (chemical mass balance) indicated that, on
average, less than 4 percent of the PM-10 mass was comprised of
secondary particulate on high concentration days. EPA believes that
this is an insignificant portion and, therefore, is proposing to grant
the exclusion from control requirements authorized under section 189(e)
for major stationary sources of PM-10 precursors.
Note that while EPA is making a general finding for this area about
precursor contribution to PM-10 NAAQS exceedances, this finding is
based on the current character of the area including, for example, the
existing mix of sources in the area. It is possible, therefore, that
future growth could change the significance of precursors in the area.
7. Enforceability Issues
All measures and other elements in the SIP must be enforceable by
IDEQ and EPA (see sections 172(c)(6), 110(a)(2)(A) of the CAA and 57 FR
13556). EPA criteria addressing the enforceability of SIP's and SIP
revisions are set forth in a September 23, 1987 memorandum (with
attachments) from J. Craig Potter, Assistant Administrator for Air and
Radiation, et. al. (see 57 FR 13541). Nonattainment area plan
provisions must also contain a program that provides for enforcement of
the control measures and other elements in the SIP (see section
110(a)(2)(C) of the CAA).
The particular control measures contained in the SIP are addressed
above under the section headed ``RACM (including RACT).'' These control
measures apply to residential wood combustion activities. The SIP
provides that the control measures for the affected activities apply
throughout the entire nonattainment area.
The SIP provided that all affected activities would be in full
compliance with the implementation of applicable control measures by
December 10, 1993. However, funding problems has delayed implementation
of the wood stove change-out and home weatherization programs until the
summer of 1994.
IDEQ is responsible for running the voluntary episodic wood burning
curtailment and public awareness programs. The curtailment program for
Pinehurst is part of a statewide program that evaluates air quality and
meteorological parameters in the PM-10 nonattainment areas on a daily
basis, during November 1 through the end of February, and declares
burning bans as necessary. The public awareness program is a broad-
based strategy designed for the entire Silver Valley (which includes
the Pinehurst NAA). IDEQ, through the Pinehurst Particulate (PM-10) Air
Quality Improvement Plan and supporting documentation, commits to
carrying out the curtailment and public awareness programs in
Pinehurst. If either of these two measures are discontinued without EPA
and public approval, then the State of Idaho would be subject to a
findings letter for non-implementation of an approved part of the plan
(see section 179(a)(4) of the CAA). This in turn could result in
Federal sanctions imposed against the State and the loss of State base
grant funds.
IDEQ's submittal and the TSD contain further information on
enforceable requirements. The TSD also contains a discussion of the
personnel and funding intended to support effective implementation of
the control measures.
8. Contingency Measures
As provided in section 172(c)(9) of the Act, all moderate
nonattainment area SIP's that demonstrate attainment must include
contingency measures (see generally 57 FR 13543-13544). These measures
were required to be submitted by November 15, 1993 for the initial
moderate nonattainment areas. Contingency measures should consist of
other available measures that are not part of the area's control
strategy. These measures must take effect without further action by the
State or EPA, upon a determination by EPA that the area has failed to
make RFP or attain the PM-10 NAAQS by the applicable statutory
deadline.
Contingency measures for the Pinehurst PM-10 nonattainment area
have not yet been submitted by IDEQ. A findings letter, dated January
13, 1994, was mailed to the Governor of Idaho which informed him that
the State had failed to make the required PM-10 contingency measures
submittal for Pinehurst. The State has until July 13, 1995 to correct
this deficiency for Pinehurst, or it will face federal highway or
offset sanctions (see section 179 of the CAA).
EPA intends to take action on the contingency measures for the
Pinehurst PM-10 nonattainment area when the requirement is submitted,
or intends to impose sanctions in the event this deficiency is not
corrected.
III. Implications of This Action
EPA is approving the plan revision submitted to EPA on April 14,
1992 for the Pinehurst nonattainment area. Among other things, IDEQ has
demonstrated that the Pinehurst moderate PM-10 nonattainment area will
attain the PM-10 NAAQS by December 31, 1994.
IV. Administrative Review
Under the Regulatory Flexibility Act, 5 U.S.C. 600 et seq., EPA
must prepare a regulatory flexibility analysis assessing the impact of
any proposed or final rule on small entities. 5 U.S.C. 603 and 604.
Alternatively, EPA may certify that the rule will not have a
significant impact on a substantial number of small entities. Small
entities include small businesses, small not-for-profit enterprises,
and government entities with jurisdiction over populations of less than
50,000.
SIP approvals under section 110 and subchapter I, part D of the CAA
do not create any new requirements, but simply approve requirements
that the state is already imposing. Therefore, because the federal SIP-
approval does not impose any new requirements, I certify that it does
not have a significant impact on any small entities affected. Moreover,
due to the nature of the federal-state relationship under the CAA,
preparation of a regulatory flexibility analysis would constitute
federal inquiry into the economic reasonableness of state action. The
CAA forbids EPA to base its actions concerning SIPs on such grounds.
Union Electric Co. v. U.S.E.P.A., 427 U.S. 246, 256-66 (S.Ct. 1976); 42
U.S.C. 7410(a)(2).
The EPA is publishing this action without prior proposal because
the Agency views this as a noncontroversial amendment and anticipates
no adverse comments. However, in a separate document in this Federal
Register publication, the EPA is proposing to approve the SIP revision
should adverse or critical comments be filed. This action will be
effective October 24, 1994 unless, by September 26, 1994 adverse or
critical comments are received.
If the EPA receives such comments, this action will be withdrawn
before the effective date by publishing a subsequent document that will
withdraw the final action. All public comments received will be
addressed in a subsequent final rule based on this action serving as a
proposed rule. The EPA will not institute a second comment period on
this action. Any parties interested in commenting on this action should
do so at this time. If no such comments are received, the public is
advised that this action will be effective October 24, 1994.
The EPA has reviewed this request for revision of the federally
approved SIP for conformance with the provisions of the 1990 Clean Air
Act Amendments enacted on November 15, 1990. The EPA has determined
that this action conforms with those requirements.
Nothing in this action should be construed as permitting or
allowing or establishing a precedent for any future request for
revision to any SIP. Each request for revision to the SIP shall be
considered separately in light of specific technical, economic and
environmental factors and in relation to relevant statutory and
regulatory requirements.
This action has been classified as a Table 2 action by the Regional
Administrator under the procedures published in the Federal Register on
January 19, 1989 (54 FR 2214-2225), as revised by an October 4, 1993
memorandum from Michael H. Shapiro, Acting Assistant Administrator for
Air and Radiation. The OMB has exempted this regulatory action from
E.O. 12866 review.
Under section 307(b)(1) of the Clean Air Act, petitions for
judicial review of this action must be filed in the United States Court
of Appeals for the appropriate circuit by October 24, 1994. Filing a
petition for reconsideration by the Administrator of this final rule
does not affect the finality of this rule for the purposes of judicial
review nor does it extend the time within which a petition for judicial
review may be filed and shall not postpone the effectiveness of such
rule or action. This action may not be challenged later in proceedings
to enforce its requirements. (See section 307(b)(2), 42 U.S.C.
7607(b)(2)).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Particulate matter.
Dated: July 5, 1994.
Gerald A. Emison,
Acting Regional Administrator.
Part 52, chapter I, title 40 of the Code of Federal Regulations is
amended as follows:
PART 52--[AMENDED]
1. The authority citation for part 52 continues to read as follows:
Authority: 42 U.S.C. 7401-7671q.
Subpart N--Idaho
2. Section 52.670 is amended by adding paragraph (c)(28) to read as
follows:
Sec. 52.670 Identification of plan.
* * * * *
(c) * * *
(28) On April 14, 1992, the State of Idaho submitted a revision to
the SIP for Pinehurst, ID, for the purpose of bringing about the
attainment of the national ambient air quality standards for
particulate matter with an aerodynamic diameter less than or equal to a
nominal 10 micrometers.
(i) Incorporation by reference.
(A) April 7, 1992 letter from Idaho Department of Health and
Welfare to EPA Region 10 submitting the Pinehurst Particulate Air
Quality Improvement Plan as a revision to the Implementation Plan for
the Control of Air Pollution in the State of Idaho. The plan has been
adopted in accordance with the authorities and requirements of the
Federal Clean Air Act and the Idaho Environmental Protection and Health
Act (Idaho Code section 39-10/et seq).
(B) SIP revision for Pinehurst Particulate Air Quality Improvement
Plan, February 5, 1992 (adopted on April 7, 1992).
[FR Doc. 94-20810 Filed 8-24-94; 8:45 am]
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