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[Proposed Rules]
[Page 19963-19991]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13ap00-25]
[[Page 19963]]
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Part II
Environmental Protection Agency
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40 CFR Part 52
Approval and Promulgation of Implementation Plans; Arizona--Maricopa County PM-10 Nonattainment Area; Serious Area Plan for Attainment of the Annual PM-10 Standard; Proposed Rule
Interim Final Determination That State Has Corrected the Plan Deficiency and Stay of Sanctions; Phoenix PM-10 Nonattainment Area, Arizona; Interim Rule
[[Page 19964]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[AZ092-002; FRL-6575-3]
Approval and Promulgation of Implementation Plans; Arizona-- Maricopa County PM-10 Nonattainment Area; Serious Area Plan for Attainment of the Annual PM-10 Standard
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: EPA proposes to approve provisions of the Revised MAG 1999 Serious Area Particulate Plan for PM-10 for the Maricopa County (Phoenix) Nonattainment Area, February 2000, and the control measures on which it relies, that address the annual PM-10 national ambient air quality standard. We also propose to grant Arizona's request to extend the Clean Air Act deadline for attaining the annual PM-10 standard in the Phoenix area from 2001 to 2006. Finally, we propose to approve two particulate matter rules adopted by the Maricopa County Environmental Services Department and Maricopa County's Residential Woodburning Restrictions Ordinance.
DATES: Comments on this proposal must be received in writing by June 12, 2000. Comments should be addressed to the contact listed below.
ADDRESSES: Comments may be mailed to: Frances Wicher, Office of Air Planning (AIR-2), EPA Region 9, 75 Hawthorne Street, San Francisco, CA 94105-3901.
A copy of docket No. AZ-MA-00-001, containing the technical support document (TSD) and other material relevant to EPA's proposed action, is available for public inspection at EPA's Region 9 office during normal business hours.
A copy of the docket is also available for inspection at: Arizona Department of Environmental Quality, Library, 3033 N. Central Avenue, Phoenix, Arizona 85012, (602) 207-2217. Maricopa Association of Governments, 302 North 1st Street, Phoenix, Arizona 85003, (602) 254- 6300.
Electronic Availability
This document and the Technical Support Document (TSD) are also available as electronic files on EPA's Region 9 Web Page at http:// www.epa.gov/region09/air.
FOR FURTHER INFORMATION CONTACT: Frances Wicher, Office of Air Planning (AIR-2), U.S. Environmental Protection Agency, Region 9, 75 Hawthorne Street, San Francisco, California 94105, (415) 744-1238, email: wicher.frances@epa.gov.
SUPPLEMENTARY INFORMATION:
Table of Contents
Summary of Today's Proposals
Summary of the MAG Plan
PM-10 Air Quality in the Phoenix Metropolitan Area
A. The Maricopa Nonattainment Area and its PM-10 Air Quality
B. PM-10 Air Quality Planning in the Phoenix Metropolitan Area
C. Clean Air Act Sanctions on the Phoenix Area
The Clean Air Act's Planning Requirements for Serious PM-10 Areas and EPA's Guidance on Meeting these Requirements
A. Implementation of Best Available Control Measures
B. Implementation of Reasonably Available Control Measures
C. Extension of the Attainment Date beyond 2001
1. Apply for an attainment date extension
2. Demonstrate that attainment by 2001 is impracticable
3. Complied with all requirements and commitments in its implementation plan
4. Demonstrate the inclusion of the most stringent measures
5. Demonstrate attainment by the most expeditious alternative date practicable
D. Separating Our Rulemaking Actions on the Annual and 24-hour Standards
Discussion of the MAG Plan's Compliance with Clean Air Act Requirements
A. Completeness of the SIP Submittals
B. Adequacy of the Transportation Conformity Budgets
C. Emission Inventory
D. Adequate Monitoring Network
E. Contribution to PM-10 Exceedances of Major Sources of PM-10 Precursors
F. Implementation of Reasonably Available and Best Available Control Measures
1. Determination of significant sources
2. Identification of potential BACM
3. Implementation of RACM and BACM and inclusion of MSM for each significant source category
a. Technology controls for on-road motor vehicle exhaust
b. Transportation control measures (TCMs) for on-road motor vehicle exhaust and paved road dust
c. Nonroad engines
d. Paved road dust
e. Unpaved parking lots
f. Disturbed vacant lands
g. Unpaved roads
h. Construction sites and activities
i. Agricultural sources
j. Residential wood combustion
k. Secondary ammonium nitrate
l. MCESD's commitments to improve compliance and enforcement of its fugitive dust rules
G. Attainment Date Extension
1. Apply for an extension
2. Demonstrate the impracticability of attainment by December 31, 2001
3. Complied with the commitments and requirements in the SIP
4. Include the most stringent measures
5. Demonstrate expeditious attainment
a. Air quality modeling b. Control measures relied on for attainment
6. Other factors that EPA may consider
a. Nature and extent of nonattainment
b. Types and number of sources or other emitting activities
c. Population exposure to concentrations above the standard
d. Presence and concentration of potentially toxic substances in the particulate
e. Technological and economic feasibility of controls
7. Conclusion on the extension request
H. Reasonable Further Progress (RFP) and Quantitative Milestones
1. Reasonable further progress
2. Quantitative milestones
I. General SIP Requirements
Proposed Action on Maricopa County Rules
A. Rule 310
B. Rule 310.01
C. Residential Woodburning Restriction Ordinance
D. CAA Section 110(l) Finding
Administrative Requirements
Summary of Today's Proposals
We are proposing to approve the serious area air quality plan for attainment of the annual PM-10 standard in the Phoenix, Arizona, metropolitan area.\1\ Our proposed actions are based on our initial determination that this plan complies with the Clean Air Act's requirements for attainment of the annual PM-10 standard in serious PM- 10 nonattainment areas.
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\1\ There are two separate national ambient air quality
standards (NAAQS) for PM-10, an annual standard of 50
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Specifically, we propose to approve the following elements of the
plan as they apply to the annual PM-10 standard:
[[Page 19965]]
We are also proposing to grant Arizona's request to extend the
attainment date for the annual PM-10 standard from December 31, 2001 to
December 31, 2006.
Finally, we are proposing to approve Maricopa County's fugitive
dust rules, Rules 310 and 301.01, and its residential woodburning
restriction ordinance.
This preamble describes our proposed actions on the Phoenix area
plan and provides a summary of our evaluation of the plan. Our detailed
evaluation of the plan can be found in the technical support document
(``EPA TSD'') that accompanies this proposal. A copy of the EPA TSD can
be downloaded from our website or obtained by calling or writing the
contact person listed above.
Summary of the MAG Plan
We are evaluating and proposing action on the Revised Maricopa
Association of Governments 1999 Serious Area Particulate Plan for PM-10
for the Maricopa County Nonattainment Area, February 2000 (``MAG
plan''). This plan was developed by the Maricopa Association of
Governments (MAG), the lead air quality planning agency in Maricopa
County, with the assistance of the Maricopa County Environmental
Services Department (MCESD), the Arizona Department of Environmental
Quality (ADEQ), and the cities and towns in the Maricopa County
nonattainment area. ADEQ submitted the final plan as a revision to the
Arizona State Implementation Plan (SIP) on February 16, 2000.
We are also evaluating and proposing action on the December 11,
1997 submittal of Serious Area Committed Particulate Control Measures
for PM-10 for the Maricopa County Nonattainment Area and Support
Technical Analysis, MAG, December 1997. This submittal contains
additional control measures that are relied on in the MAG plan. We
consider the measures in this submittal to be part of the MAG plan and
have evaluated them as such.
Finally, we are also evaluating and proposing to act on the most
recent revisions to MCESD's Rule 310, Fugitive Dust Sources (adopted
February 16, 2000) and Rule 310.01, Fugitive Dust from Open Areas,
Vacant Lots, Unpaved Parking Lots, and Unpaved Roadways (adopted
February 16, 2000). We are also proposing to approve the revised
Maricopa County Residential Woodburning Restrictions Ordinance (adopted
November 17, 1999).
As submitted, the revised MAG plan consists of the main plan
document, four volumes of technical appendices, and four volumes of
commitments from various agencies to implement PM-10 controls. The plan
contains a 1994 regional PM-10 emissions inventory and uses the urban
airshed model/limited chemistry version (UAM/LC) to model air quality
in 1995 as a base year and in 2006 as the attainment year. The plan
includes a BACM analysis and a demonstration that attainment by 2001 is
impracticable. It also includes the State's request for a five year
extension of the attainment date, a demonstration that the plan
provides for the most stringent measures found in other areas' plans or
used in practice, and a demonstration of attainment by December 31,
2006. The plan shows that the principal sources contributing to PM-10
exceedances in the Phoenix area are fugitive dust sources, such as
construction sites, vacant lots, paved and unpaved roads, and various
other dust sources. The principal controls relied on for attainment are
controls on these fugitive dust sources.
The MAG plan addresses both the annual and 24-hour PM-10 standards.
We are not at this time proposing any actions regarding the plan's
compliance with the statutory requirements relating to the 24-hour
standard. As we explain in more detail later, the annual PM-10 standard
is a separate air quality standard from the 24-hour one; therefore, we
can and must separately evaluate a plan's compliance with the statutory
requirements for each standard. We do not need to do these reviews
concurrently.
The MAG plan also contains contingency measures as required by CAA
section 172(c)(9). We are not proposing action on these contingency
measures at this time. Contingency measures are a distinct provision of
the Clean Air Act that we may act on separately from the attainment
requirements.
PM-10 Air Quality in the Phoenix Metropolitan Area
A. The Maricopa Nonattainment Area and its PM-10 Air Quality
The Maricopa County (Phoenix) PM-10 nonattainment area is located
in the eastern portion of Maricopa County and encompasses the cities of
Phoenix, Mesa, Scottsdale, Tempe, Chandler, Glendale as well as 17
other jurisdictions and considerable unincorporated County lands.\2\ 40
CFR 81.303. The area is home to almost 3 million people.
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\2\ The Maricopa nonattainment area also includes the town of
Apache Junction in Pinal County. Apache Junction is covered by a
separate air quality plan and will be addressed in a later action.
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The area violates both the annual and 24-hour PM-10 standards. In
1990, the area was designated nonattainment for PM-10 and classified as
moderate. In 1996, because of continuing violations of both PM-10
standards, the area was reclassified to serious. 61 FR 21372 (May 10,
1996).
As noted before, the principal contributors to elevated PM-10
levels in the Phoenix area are fugitive dust sources such as
construction sites, unpaved roads, vacant lots and paved road dust.
Also contributing to the PM-10 problem, but to a much lesser degree
than fugitive dust, are internal and external combustion sources
including directly-emitted PM-10 from automobiles, trucks, construction
equipment, bus, residential woodburning and industrial, commercial, and
residential use of natural gas and fuel oil. See MAG plan, 3-5.
B. PM-10 Air Quality Planning in the Phoenix Metropolitan Area
The MAG plan is the latest in a series of air quality plans
addressing the PM-10 problem in Phoenix. These previous plans are:
[[Page 19966]]
number of significant sources of PM-10, including unpaved roads. The
failure to provide for the implementation of RACM also meant that the
plan could no longer conclusively demonstrate the impracticability of
attainment of the annual standard by December 31, 1994, so we also
disapproved the impracticability demonstration. 63 FR 15919, 15925
(April 1, 1998).
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\3\ The FIP's requirements for unpaved roads, unpaved parking
lots and disturbed vacant lots are codified at 40 CFR 52.128. We
withdrew the FIP's agricultural requirements, formerly codified at
40 CFR 52.127, when we approved similar State requirement in 1999.
64 FR 34726 (June 29, 1999).
\4\ At the time we promulgated the FIP in 1998, the moderate PM-
10 area deadline of December 31, 1994 had passed and we had
reclassified the Phoenix area to serious. As a result the only
statutory attainment deadline then applicable to the Phoenix area,
and thus the deadline applicable to our moderate area FIP, was the
serious area deadline, i.e., as expeditiously as practicable but not
later than December 31, 2001. See 63 FR 15919, 15926.
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A more detailed history of PM-10 planning in the Phoenix area can
be found in the EPA TSD.
C. Clean Air Act Sanctions on the Phoenix Area
Our 1998 disapprovals of parts of the 1991 MAG moderate area plan
started sanction clocks under CAA section 179(a). Under section 179(a),
once we disapprove a SIP provision because it fails to meet a CAA
requirement, a State has 18 months to correct the deficiency that
resulted in the disapproval before the first of two sanctions goes into
place. If the state still has not corrected the deficiency within 24
months of the disapproval, the second sanction goes into place.
The two CAA sanctions are a limitation on certain highway approvals
and funding and an increase in the offset ratio to 2 to 1 for any major
new stationary source or major modification. See CAA section 179(b).
Our sanctions regulations provide that the first sanction to be imposed
is the offset ratio unless we have established at the time of the
disapproval that the highway sanction will be first. 40 CFR 52.31(d).
On August 3, 1998, we published our disapprovals of the RACM and
attainment demonstrations for the annual standard in the 1991 MAG
moderate area plan. 63 FR 41326. When these disapprovals became
effective 30 days later on September 2, 1998, the sanction clocks
started. The first of these sanction clocks expired on March 2, 2000
and the 2:1 offset sanction is now in place in the Phoenix area. The
second sanction clock for the highway funding limitations is set to
expire on September 2, 2000.
Under section 179(a) and our sanctions regulations at 40 CFR
52.31(d)(1), we must approve a SIP revision that corrects the
deficiencies to permanently end the sanctions clocks and lift any
imposed sanctions. However, we may temporarily stay the clocks and any
imposed sanctions if we propose to approve a SIP revision that corrects
the deficiencies and have issued an interim final determination that
the State has corrected the deficiencies. 40 CFR 52.31(d)(2)(i).
In a rule being published concurrently with this proposal, we are
issuing an interim final determination that, based our proposed
findings here, Arizona has more than likely corrected the deficiencies
that resulted in our August 1998 disapprovals.
The Clean Air Act's Planning Requirements for Serious PM-10 Areas
and EPA's Guidance on Meeting these Requirements
The Phoenix area is a PM-10 nonattainment area that has been
reclassified to serious because it failed to attain by the moderate
area attainment date of December 31, 1994. Such an area must submit,
within 18 months of the reclassification, revisions to its
implementation plan that address the CAA requirements for serious PM-10
nonattainment areas. CAA section 189(b)(2). These requirements are:
(a) assurances that best available control measures (BACM) for the
control of PM-10 shall be implemented no later than 4 years after the
area is reclassified (CAA section 189(b)(1)(B)); \5\
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\5\ When a moderate area is reclassified to serious, the
requirement to implement RACM in section 189(a)(1)(C) remains and is
augmented by the requirement to implement BACM. Thus, a serious area
PM-10 plan must, in addition to BACM, provide for the implementation
of RACM as expeditiously as practicable to the extent that the RACM
requirement has not been satisfied in the area's moderate area plan.
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(b) assurances that best available control technology (BACT) on
major stationary sources of PM-10 precursors shall be implemented no
later than 4 years after the area is reclassified except where EPA has
determined that such sources do not contribute significantly to
exceedances of the PM-10 standards (CAA section 189(e));
(c) a demonstration (including air quality modeling) that the plan
will provide for attainment as expeditiously as practicable but no
later than December 31, 2001, or, where the State is seeking an
extension of the attainment date under section 188(e), a demonstration
that attainment by December 31, 2001 is impracticable (CAA sections
188(c)(2) and 189(b)(1)(A));
(d) quantitative milestones which are to be achieved every 3 years
and which demonstrate reasonable further progress (RFP) toward
attainment by the applicable attainment date (CAA sections 172(c)(2)
and 189(c)); and
(e) a comprehensive, accurate, current inventory of actual
emissions from all sources of PM-10. (CAA sections 172(c)(3)).
Serious area PM-10 plans must also meet the general requirements
applicable to all SIPs including reasonable notice and public hearing
under section 110(l), necessary assurances that the implementing
agencies have adequate personnel, funding and authority under section
110(a)(2)(E)(i) and 40 CFR 51.280; and the description of enforcement
methods as required by 40 CFR 51.111.
Except for the requirements for the implementation of RACM and BACM
and for extension requests, we will discuss our policies for each of
these requirements when we discuss our evaluation of that section of
the MAG plan later in this preamble.
[[Page 19967]]
We have issued a General Preamble, 57 FR 13498 (April 16, 1992) and
57 FR 18070 (April 28, 1992), and Addendum to the General Preamble
(``Addendum''), 59 FR 41998 (August 16, 1994), describing our
preliminary views on how we intend to review SIPs submitted to meet the
Clean Air Act's requirements for PM-10 plans. We have also issued other
guidance documents related to PM-10 plans or provisions of these plans.
These other guidance documents will be cited as appropriate.
A. Implementation of Best Available Control Measures
Under section 189(b)(2), serious area PM-10 plans must provide
assurances that BACM will be implemented in the area no later than four
years after the area is reclassified as serious. For Phoenix, the BACM
implementation deadline is June 10, 2000.
The Act does not define what constitutes BACM. We consider BACM to
be a particular level of control, in this case the best, on a source or
source category. More specifically, we have defined BACM to be, among
other things, the maximum degree of emission reductions achievable from
a source or source category which is determined on a case-by-case
basis, considering energy, economic and environmental impacts. Addendum
at 42010. We also consider BACM as going beyond existing RACM-level
controls, such as expanding the use of RACM controls (e.g., paving more
miles of unpaved roads). Addendum at 42013. Additionally, we believe
that BACM should emphasize prevention rather than remediation (e.g.,
preventing track out at construction sites rather than simply requiring
clean up of tracked-out dirt). Addendum at 42013.
A serious area plan must provide for the implementation of BACM on
each significant (i.e., non-de minimis) source category. Addendum at
42011. In guidance, we have established a presumption that a
``significant'' source category is one that contributes 1
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\6\ This principle is best illustrated by an example: In Area A,
attainment of the annual standard by December 31, 2001 requires that
total PM-10 emissions in the area be reduced to 200 tons per day
(tpd). After application of BACM to all source categories above the
proposed de minimis level, total emissions in the area are reduced
to 220 tpd. BACM on the proposed de minimis source categories would
reduce total emissions a further 5 tons to 215 tpd. Since
application of BACM to the proposed de minimis source categories
still leaves emissions above the attainment level of 200 tpd, the
proposed de minimis level is appropriate.
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We have outlined in our guidance a multi-step process for
identifying BACM. Addendum at 42010-42014. The steps are:
1. develop a detailed emission inventory of PM-10 sources and
source categories,
2. model to evaluate the impact on PM-10 concentrations over the
standards of the various sources and source categories to determine
which are significant,
3. identify potential BACM for significant source categories
including their technological feasibility, costs, and energy and
environmental impacts if needed to determine BACM, and
4. provide for the implementation of the BACM or provide a reasoned
justification for rejecting any potential BACM.
B. Implementation of Reasonably Available Control Measures
When a moderate area is reclassified to serious, the requirement to
implement RACM in section 189(a)(1)(C) remains. Thus, a serious area
PM-10 plan must also provide for the implementation of RACM as
expeditiously as practicable to the extent that the RACM requirement
has not been satisfied in the area's moderate area plan.
However, we do not normally conduct a separate evaluation to
determine if a serious area plan's measures also meet the RACM
requirements as interpreted by us in the General Preamble at 13540.
This is because in our serious area guidance (Addendum at 42010), we
interpret the BACM requirement, as generally subsuming the RACM
requirement (i.e. if we determine that the measures are indeed the
``best available,'' we have necessarily concluded that they are
``reasonably available''). Therefore, a separate analysis to determine
if the measures represent a RACM level of control is not necessary.
Consequently, our proposed approval of the MAG plan's provisions
relating to the implementation of BACM is also a proposed finding that
the plan provides for the implementation of RACM.
C. Extension of the Attainment Date Beyond 2001
Section 188(e) of the Act allows us to extend the attainment date
for a serious area for up to five years beyond 2001 if attainment by
2001 is impracticable. However, before we may grant an extension of the
attainment date, the State must first:
1. apply to us for an extension of the PM-10 attainment date beyond
2001,
2. demonstrate that attainment by 2001 is impracticable,
3. have complied with all requirements and commitments applying to
the area in its implementation plan,
4. demonstrate to our satisfaction that its serious area plan
includes the most stringent measures that are included in the
implementation plan of any state and/or are achieved in practice in any
state and are feasible for the area, and
5. submit a demonstration of attainment by the most expeditious
alternative date practicable.
In determining whether to grant an extension and the appropriate
length of the attainment date extension, we may consider:
1. the nature and extent of the nonattainment problem,
2. the types and number of sources or other emitting activities in
the area (including the influence of uncontrollable natural sources and
international transport),
3. the population exposed to concentrations in excess of the
standard,
4. the presence and concentration of potentially toxic substances
in the mix of particulate emissions in the area, and
5. the technological and economic feasibility of various control
measures.
We may grant only one extension for an area and that extension
cannot be for more than 5 years after 2001; that is, the extended
attainment date can be no later than December 31, 2006. CAA section
188(e).
To date, we have not issued any policy or regulation interpreting
the attainment date extension requirements for urban areas like
Phoenix. Therefore, before reviewing Arizona's request for an
extension, we will first discuss how we propose to interpret section
188(e).
The following is our preliminary interpretation of the section
188(e) requirements and we request comment on it. We emphasize that
this is our preliminary view and it is subject to modification as we
gain more experience reviewing on extension requests from other areas.
[[Page 19968]]
We have listed above the five requirements a State must meet before
we can consider granting an attainment date extension. We discuss each
requirement in order:
1. Apply for an Attainment Date Extension
The State must apply in writing to EPA for an extension of the
attainment deadline. The request should accompany the SIP submittal
containing the most expeditious alternative attainment demonstration.
The public must be provided reasonable notice and a public hearing on
the request before it is submitted.
Extension requests are not SIP submittals per se and are therefore
not subject to the requirements of the Clean Air Act and our
regulations for public notice and hearing on SIP revisions. However,
because they can greatly affect the content and ultimate approvability
of a serious area PM-10 plan, we believe a state must give the public
an opportunity, consistent with the requirements for SIP revisions, to
comment on an extension request prior to submitting it to us.
2. Demonstrate That Attainment by 2001 is Impracticable
In order to demonstrate impracticability, the plan must show that
the implementation of BACM (as determined by our guidance) on
significant source categories will not bring the area into attainment
by December 31, 2001. BACM is the required level of control for serious
areas that must be in place before the 2001 attainment date; therefore,
we believe that it is reasonable to interpret the Act to require that a
state provide for at least the implementation of BACM on significant
source categories before it can claim impracticability of attainment by
2001. This interpretation parallels our interpretation of the
impracticability option for moderate PM-10 nonattainment areas in
section 189(a)(1)(B). In moderate areas, RACM was required before a
moderate area plan could show impracticability of attainment by 1994,
the moderate area attainment deadline. General Preamble at 13544.
The statutory provision for demonstrating impracticability requires
that the demonstration be based on air quality modeling. See section
189(b)(1)(A).
3. Complied With all Requirements and Commitments in its Implementation
Plan
We interpret this criterion to mean that the State has implemented
the control measures in the SIP revisions it has submitted to us to
address the CAA requirements in sections 172 and 189 for PM-10
nonattainment areas.
We read this provision not to require the area to have a fully
approved SIP that meets the CAA's requirements for moderate areas. We
base this reading on the plain language of section 188(e) which
requires the state to comply with all requirements and commitments
pertaining to that area in the implementation plan but does not require
that the state comply with all requirements pertaining to the area in
the Act. For the same reason we also read this provision not to bar an
extension if all or part of an area's moderate area plan is disapproved
or has been promulgated as a FIP.
4. Demonstrate the Inclusion of the Most Stringent Measures
The fourth extension criterion requires the State to ``demonstrate
to the satisfaction of the Administrator that the plan for the area
includes the most stringent measures that are included in the
implementation plan of any State, or are achieved in practice in any
State, and can feasiblely be implemented in the area.'' CAA section
188(e).
The requirement for most stringent measures (MSM) is similar to the
requirement for BACM. We define BACM to be, among other things, the
maximum degree of emission reduction achievable from a source or source
category which is determined on a case by case basis considering
energy, economic and environmental impacts. Addendum at 42010. The Act
establishes the deadline for implementing BACM as four years after an
area's reclassification to serious. CAA section 189(b)(1)(A).
We proposed to define a ``most stringent measure'' in a similar
manner: the maximum degree of emission reduction that has been required
or achieved from a source or source category in other SIPs or in
practice in other states and can feasiblely be implemented in the area.
The Act does not specify an implementation deadline for MSM. Because
the clear intent of section 188(e) is to minimize the length of any
attainment date extension, we propose that the implementation of MSM
should be as expeditiously as practicable.
Given this similarity between the BACM implementation and MSM
requirements, we believe that determining MSM should follow a process
similar to determining BACM, but with one additional step, to compare
the potentially most stringent measure against the measures already
adopted in the area:
1. develop a detailed emission inventory of PM-10 sources and
source categories,
2. model to evaluate the impact on PM-10 concentrations over the
standards of the various source categories to determine which are
significant for the purposes of adopting MSM,
3. identify the potentially most stringent measures in other
implementation plans or used in practice in other States for each
significant source category and, for each measure, determine their
technological and economic feasibility for the area,
4. compare the potentially most stringent measures for each
significant source category against the measures, if any, already
adopted for that source category, and
5. provide for the adoption and expeditious implementation of any
MSM that is more stringent than existing measures or, in lieu of
adoption, provide a reasoned justification for rejecting the potential
MSM, i.e., why such measures cannot be feasiblely implemented in the
area.
The level of control resulting from a most stringent measure
depends on how well other areas have chosen to control their sources.
If a source category has not been well controlled in other areas then
MSM may in fact result in a rather low level of control. This contrasts
with BACM which is determined independently of what other areas have
done and depends only on what is the best level of control feasible for
an area.
Because BACM is the best level of control feasible for an area, it
would be easy for the MSM requirement to result in no more controls and
no more emission reductions in an area than result from the
implementation of BACM. Given the strategy in the nonattainment
provisions of the Act to offset longer attainment time frames with more
stringent control requirements, we need to interpret the MSM provision
to assure that it results in additional controls beyond the set of
measures adopted as BACM. The primary ways to do this are (1) to
require that more sources and source categories be subject to MSM
analysis than to BACM analysis, that is, by lowering the threshold for
what is considered a de minimis source category and (2) to require
reanalysis of any measures garnered from other areas that were rejected
during the BACM analysis because they could not be implemented by the
BACM-implementation deadline to see if they
[[Page 19969]]
are now feasible for the area given the longer attainment date.
De Minimis Thresholds. What constitutes a de minimis source
category for BACM is dependent upon the specific facts of the
nonattainment problem under consideration. In particular, it depends
upon whether requiring the application of BACM for such sources would
make the difference between attainment and nonattainment by the serious
area deadline. We propose to use a similar approach for judging what
constitutes a de minimis source category for MSM but instead of the
attainment/nonattainment test, we propose to use a test of whether MSM
controls on the de minimis sources would result in more expeditious
attainment.
We would not review an MSM analysis in a plan if the plan did not
demonstrate expeditious attainment since one prerequisite for granting
an extension is that the plan demonstrate attainment. Therefore, any de
minimis standard for MSM that relied on the difference between
attainment and nonattainment would be meaningless because no additional
controls are needed for attainment beyond those already in the plan.
Our responsibility under section 188(e), however, is to grant the
shortest practicable extension of the attainment date by assuring the
plan provides for attainment as expeditiously as practicable. Thus, one
means of determining an appropriate de minimis level is to determine if
applying MSM to the proposed de minimis source categories would
meaningfully expedite attainment. If it did, then the de minimis level
is too high, and if it did not, then the de minimis level is
appropriate.\7\
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\7\ In extension areas, the applicable control requirement after
the December 31, 2001 attainment date is the MSM and expeditious
attainment requirements of section 188(e). Thus, for measures
implemented after December 31, 2001, a state need only show that the
measure meets at minimum the MSM level of control and, combined with
all other measures, is sufficient for expeditious attainment. A
state has no obligation to show that the measure meets a BACM-level
of control.
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Technological Feasibility. In the MSM analysis, a state must
evaluate the application of controls from elsewhere to sources in its
own area. In many cases, these sources are already subject to local
control measures. In these situations, part of determining if a control
is technologically feasible is determining if the new control can be
integrated with the existing controls without reducing or delaying the
emission reductions from the existing control. If it cannot, then we
would not, in general, consider the measure to be technologically
feasible for the area.
Economic Feasibility. Because cost is rarely used to justify
rejection of a measure in the MAG plan, we will not attempt to
establish a general guide for evaluating when a measure is economically
infeasible but instead will address the issue on a case-by-case basis
as needed.
We propose to use the following approach in evaluating the
selection of the most stringent among multiple measures, i.e.,
evaluating the determination of when one is more stringent than
another:
1. The determination will be made on a source category basis. When
only a single measure is applicable to a source category then we will
compare the measures directly. However, in many cases multiple measures
apply to a single source category (e.g., unpaved roads which in the MAG
plan are controlled both by Rule 310.01 and through City and County
commitments). In these cases, we will evaluate the impact of the
overall control strategy on emissions in the source category against
the impact of the overall control strategy on the source category in
other areas and will not compare individual measures within the source
category.
2. We will review all the elements of a rule that apply to a
specific type of source as an inseparable measure. A rule's
applicability and emission limitations (as they apply to a single type
of source) together define its stringency. They are not separable
elements that can be compared in isolation to another rule.
3. Because stringency is based on an emissions level, we will not
use a measure's implementation mechanisms (e.g., rule versus
commitment), funding level, compliance schedule, resources available
for enforcement, or other similar items as criteria for judging
relative stringency. (We do consider these items when judging whether
the plan provides for implementation of MSM.)
Finally, we address how we view the ``to the satisfaction of the
Administrator'' qualifier on the requirement that the State demonstrate
that its plan includes the most stringent measures. The presence and
wording of this qualifier indicate that Congress granted us
considerable discretion in determining whether a plan in fact includes
MSM. Under the terms of section 188(e), we believe that we can still
accept an MSM demonstration even if it falls short of having every MSM
possible. To intuit the limits of this discretion, we again look to the
overall intent of section 188(e), that we grant as short an extension
as practicable. In concrete terms, this means that when judging the
overall adequacy of the MSM demonstration, we will give more weight to
a failure to include MSM for source categories that contribute the most
to the PM-10 problem in Phoenix and to the failure to include measures
that could provide for more expeditious attainment and less weight to a
failure to include MSM for source categories that contribute little to
the PM-10 problem and/or would not expedite attainment.
5. Demonstrate Attainment by the Most Expeditious Alternative Date
Practicable
Section 189(b)(1)(A) requires that a serious area plan demonstrate
attainment, using air quality modeling, by the most expeditious date
practicable after December 31, 2001. This demonstration is the final
criterion that must be met before we may grant an extension request.
Our determination of whether the plan provides for attainment by
the most expeditious date practicable will depend on whether the plan
provides for implementation of BACM by the BACM implementation deadline
and MSM as expeditiously as practicable.
Please see section 4 of the EPA TSD for an additional discussion of
our proposed interpretation of the extension requirements.
D. Separating Our Rulemaking Actions on the Annual and 24-hour
Standards
As we discussed above, there are two PM-10 NAAQS, an annual
standard of 50
The two PM-10 standards are independent and must be addressed
independently by states in their SIPs. This independence was
highlighted by the Ninth Circuit Court of Appeals in Ober v. EPA, 84
F.3d 304 (9th Cir. 1996). In Ober, the Court was reviewing our approval
of the MAG moderate area plan:
The general provisions of the Clean Air Act repeatedly emphasize
that implementation plans must provide for attainment of the NAAQS
as expeditiously as practicable. For PM-10, the EPA promulgated two
separate NAAQS-the annual standard and the 24-hour standard-which
differ in the following
[[Page 19970]]
respects. First, the 24-hour standard offers protection against
dangerous short-term exposures to high PM-10 levels, a protection
that is distinct from the protection against chronic degradation in
lung function provided by the annual standard. Second, the sources
of PM-10 violation differ for the annual and the 24-hour: violations
of the 24-hour standard are generally caused by localized sources
such as construction projects, whereas violations of the annual
standard tend to be caused by more diverse, dispersed sources.
Third, control measures differ in effectiveness for the 24-hour
standard and the annual standard.
These differences emphasize the importance of viewing PM-10's
two NAAQS individually and of requiring independent treatment of
them in an implementation plan. . . . . Such independent treatment
furthers the Clean Air Act's goals of protecting health and achieve
clean air.
Ober at 309 (emphasis added).
If a state must treat each PM-10 NAAQS independently in the
implementation plan, then we also must treat each PM-10 NAAQS
independently when reviewing the plan's compliance with the Clean Air
Act. Therefore, it is necessary for us to review the MAG plan's
compliance against the CAA requirements as they apply to the annual
standard and again review them against the CAA requirements as they
apply to the 24-hour standard. There is no mandate that we conduct
these reviews concurrently even if Arizona submitted a single document
to meet the requirements for both standards since, effectively, we must
treat it as if it contained two separate plans.
We have chosen not to act at this time on the 24-hour provisions of
the revised MAG plan because the State is still working on quantifying
emission reductions from the best management practice measures (BMPs)
intended to reduce fugitive dust from agricultural sources. Attainment
of the 24-hour standard in the Phoenix area, unlike the annual
standard, depends in part on emission reductions from these BMPs. Once
Arizona quantifies the reductions, it will revise the 24-hour
attainment demonstrations and resubmit them to us. We expect these
changes later this year. We do not believe it is an efficient use of
our resources to act now on the 24-hour provisions currently in the MAG
plan knowing that they will be substantially revised prior to our
statutory deadline to act on them.
Discussion of the MAG Plan's Compliance with the Clean Air Act's
Requirements
The following sections present a condensed discussion of our
evaluation of the MAG plan's compliance with the applicable CAA
requirements for attainment of the annual PM-10 standard. Our complete
evaluation is found in the EPA TSD for this proposal. We urge anyone
wishing to comment on this proposal to first review the TSD before
preparing comments. A copy of the TSD can be downloaded from our
website or obtained by calling or writing the contact person listed
above.
A. Completeness of the SIP Submittals
The first step we take after receiving a SIP submittal is to
determine if it is complete. CAA section 110(k)(1)(B) requires that we
review all SIPs and SIP revisions for completeness within 60 days of
receipt of the submittal. The completeness review allows us to quickly
determine if a state has submitted a SIP revision, including all needed
supporting material, on which we can take action. We make completeness
determinations using criteria we have established in 40 CFR part 51,
appendix V.
We found ADEQ's February 16, 2000 submittal (received on February
23, 2000) of the final revised MAG serious area PM-10 plan complete. We
notified the State of our completeness determination on February 25,
2000. See Letter, David P. Howekamp, EPA, to Jacqueline Schafer, ADEQ.
If we do not make a completeness determination, a submittal becomes
complete by default 6 months after we receive it. See 100(k)(1)(B). We
did not review the 1997 submittal of control measures for completeness
and it became complete by default on June 15, 1998.
We found Arizona's submittals containing MCESD's Rule 310 and
310.01 and the revised Maricopa County residential woodburning
ordinance complete on March 31, 2000.
B. Adequacy of the Transportation Conformity Budgets
Section 176(c) of the Clean Air Act requires that federally funded
or approved transportation plans, programs, and projects in
nonattainment areas ``conform'' to the area's air quality
implementation plans. Conformity ensures that federal transportation
actions do not worsen an area's air quality or interfere with its
meeting the air quality standards. We have issued a conformity rule
that establishes the criteria and procedures for determining whether or
not transportation plans, programs, and project conform. See 40 CFR
part 93, subpart A.
One of the primary tests for conformity is to show transportation
plans and improvement programs will not cause motor vehicle emissions
higher than the levels needed to make progress toward and meet the air
quality standards. The motor vehicle emissions levels needed to make
progress toward and meet the air quality standards are set in an area's
attainment and/or reasonable further progress (RFP) plans and are known
as the ``emissions budget for motor vehicles.'' Emissions budgets are
established for specific years and specific pollutants. See 40 CFR
93.118(a).
Before an emissions budget in a submitted SIP revision may be used
in a conformity determination, we must first determine that it is
adequate. The criteria by which we determine adequacy of submitted
emission budgets are outlined in our conformity rule in 40 CFR
93.118(e)(4).
The MAG plan establishes a mobile source emissions budget of 59.7
mtpd. This regional budget is applicable for both the annual and 24-
hour PM-10 standards. The on-road mobile portion of the budget, which
includes emissions from reentrained road dust, vehicle exhaust, and
travel on unpaved roads, is 58.6 mtpd. The road construction portion of
the budget is 1.1 mtpd. MAG plan, p. 8-13.
On March 30, 2000, we have found adequate for transportation
conformity purposes this motor vehicle emission budget. As a result of
our adequacy finding, MAG and the Federal Highway Administration are
required to use this budget in future conformity analyses.
C. Emission Inventory
CAA section 172(c)(3) requires all nonattainment area plans to
contain a comprehensive, accurate, and current inventory. Our policies
require that the inventory be fully documented.
The MAG plan describes annual and average annual day emissions for
1994 from point, area, nonroad, on-road, and nonanthropogenic sources
in the Maricopa County portion of the 2,880 square mile nonattainment
area. The inventory includes emissions of PM-10, PM-2.5, ammonia
(NH
The inventory shows that the dominant sources of emissions in the
Phoenix area are paved road dust (39.1 percent), unpaved roads, (21.6
percent) and construction-related fugitive dust (20.1 percent). Much
lower but still important contributors are directly-emitted PM-10 from
non-road engines (7.0 percent) and on-road motor vehicles (3.3
percent), all stationary area sources, e.g., woodburning (6.1 percent)
and stationary point sources (2.7 percent). MAG plan, Table 3-1.
Generally the inventories are very well documented with the
[[Page 19971]]
documentation exceeding our guidance requirements.
Current: The base year, 1994, is a reasonably current year,
considering the length of time needed to develop an inventory, perform
the modeling, develop and adopt control measures, and hold public
hearings on such a large and technically-complex plan like the MAG
plan.
Comprehensive: The MAG plan inventories are fairly complete,
considering a few emission factors are unknown for some of the smaller
sources of PM-10. The inventories did not include emissions of volatile
organic compounds (VOC) which is a precursor of secondary PM-10 because
the plan found there is a negligible impact on ambient measurements of
PM-10 from VOC aerosol. We concur with this finding and that VOC
sources need not be inventoried for the PM-10 plan.
Accurate: In developing the inventory, MAG and MCESD closely
followed our guidance relative to the use of emission factors, activity
estimates, and growth and control factors, and the other source
specific emission estimation methodologies (continuous emission
monitoring, annual stack tests, and mass balance methods). Source
specific methods were used to the maximum extent possible as they are
inherently more accurate than emission factors. The relative accuracy
of each estimate underwent the prescribed quality assurance procedures
to eliminate all possible errors. The inventory is thus as accurate as
inventories can be.
Because we find that the inventory is current, comprehensive, and
accurate, we propose to approve it under CAA section 172(c)(3).
D. Adequate Monitoring Network
CAA section 110(a)(2)(B)(i) requires States to establish and
operate air monitoring networks to compile data on ambient air quality
for all criteria pollutants. Our regulations in 40 CFR part 58
establishes specific regulatory requirements for operating air quality
surveillance networks to measure ambient concentrations of PM-10,
including measurement method requirements, network design, quality
assurance procedures, and in the case of large urban areas, the minimum
number of monitoring sites designated as National Air Monitoring
Stations (NAMS).
The MAG plan does not specifically address the adequacy of the PM-
10 monitoring network in the Phoenix area. There is no requirement that
it does. We are reviewing the adequacy of the monitoring network here
because the plan relies on ambient data to characterize the extent and
severity of the PM-10 problem in the Phoenix area and we need to assure
that the monitoring network is adequate for this purpose.
In 1995, the base year for the air quality modeling, there were 18
monitoring sites collecting data in the Phoenix area, all of which were
operated in accordance with our regulations. Most of these PM-10
monitoring sites were neighborhood scale sites with an objective of
assessing population exposure. Given the widespread nature of the
emission sources in the Phoenix area, we believe this focus was
appropriate and that the network was adequate to characterize the
extent and severity of the PM-10 problem in 1995.
E. Contribution to PM-10 Exceedances of Major Sources of PM-10
Precursors
Under CAA section 189(e), a state must apply the control
requirements applicable to major stationary sources of PM-10 to major
stationary sources of PM-10 precursors, unless we determine such
sources do not contribute significantly to PM-10 levels in excess of
the NAAQS in the area. For the serious area plan, a ``major source'' is
one that emits or has the potential to emit over 70 English tons per
year (tpy) of sulfur oxides (SOx), nitrogen oxides (NOx), or ammonium.
PM-10 precursors react in the atmosphere to form ``secondary''
particulate, secondary because it is not directly emitted from the
source. The MAG plan does not provide specific information on the
impact of major precursor sources on Phoenix PM-10 levels; however, it
does provide sufficient information on the contribution of total
secondary particulates to PM-10 levels and the emissions from major
precursor sources to estimate the impact.
All major stationary sources of PM-10 precursors are estimated to
contribute just 0.24
We believe that this small contribution is insignificant for the
Phoenix area. PM-10 levels above the annual standard in Phoenix are
almost exclusively caused by a few large source categories of fugitive
dust, and it is BACM-level controls on these sources that are the key
to expeditious attainment of the annual standard in the Phoenix area
and not controls on small contributors such as major sources of PM-10
precursors.
We, therefore, propose to determine that major sources of PM-10
precursors do not contribute significantly to PM-10 levels in excess of
the PM-10 NAAQS in the Phoenix area. As a result, Arizona is not
required to apply BACT to major sources of PM-10 precursors in the
Phoenix area.
F. Implementation of Reasonably Available and Best Available Control
Measures
CAA section 189(b)(1)(B) requires that a serious area PM-10 plan
provide for the implementation of BACM within four years of
reclassification to serious. For Phoenix, this deadline is June 10,
2000. BACM must be applied to each significant area-wide source
category. Addendum at 42011. As discussed above, we have established a
four-step process for evaluating BACM in serious area PM-10 plans.
1. Determination of Significant Sources
The first step in the BACM analysis is to develop a detailed
emission inventory of PM-10 sources and source categories that can be
used in modeling to determine their impact on ambient air quality.
Addendum at 42012.
The MAG plan uses three modeling studies of PM-10 sources in the
Phoenix area to identify significant source categories. One of these
studies evaluated significant sources using chemical mass balance (CMB)
modeling performed on monitoring samples collected at 6 sites in 1989-
1990. The two other studies evaluated significant sources using
dispersion modeling of sources around 6 monitoring sites using data
from 1992 through 1995.\8\
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\8\ These studies are ``The 1989-90 Phoenix PM-10 Study,''
Desert Research Institute, April 1991; ``Particulate Control Measure
Feasibility Study,'' Sierra Research, January 1997; and ``Plan for
Attainment of the 24-hour PM-10 Standard, Maricopa County PM-10
Nonattainment Area,'' ADEQ, May 1997.
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From these evaluations, the MAG plan identified 8 significant
source categories and 12 insignificant source categories. MAG plan, p.
9-6.
The final list of significant source categories did not distinguish
between those categories that are significant for the 24-hour standard
and those significant for the annual standard; although previous
studies have shown that some source categories are significant only for
one or the other standard. Because the MAG plan did not distinguish
significant source categories between the two standards, we will treat
each of the listed significant source
[[Page 19972]]
categories as significant for the annual standard.
For the annual standard, the MAG plan demonstrates that its
selection of significant source categories is appropriate by showing
that control on the de minimis source categories would not make the
difference between attainment and nonattainment of the annual standard
by 2001. According to the plan, total emissions in the area need to be
reduced to 130 mtpd to attain the annual standard by 2001. After
application of BACM, total emissions are reduced to 152 mtpd. MAG plan,
p. 9-11. The 12 de minimis sources categories contribute in total 10.3
mtpd. MAG plan, Table 9-a. Totally eliminating these source categories
would reduce total regional emissions to 142 mtpd, still 12 mtpd above
the regional emissions level needed for attainment. MAG plan, pp. 9-10
through 9-12.
The 8 significant source categories are:
1. Paved road travel.
2. Unpaved road travel (includes unpaved parking lots).
3. Industrial paved road travel (paved and unpaved).
4. Construction site preparation (includes disturbed vacant lots
that are not undergoing construction).
5. Agricultural tilling (includes all agricultural sources).
6. Residential wood combustion.
7. On-road and non-road motor vehicle exhaust.
8. Secondary ammonium nitrate.
MAG Plan, Table 9-1.
The 12 de minimis source categories are:
1. Stationary point sources.
2. Fuel combustion (excluding residential wood combustion).
3. Waste/open burning.
4. Agricultural harvesting.
5. Cattle feedlots.
6. Structural/vehicle fires.
7. Charbroiling/frying meat.
8. Marine vessel exhaust.
9. Airport ground support exhaust.
10. Railroad locomotive exhaust.
11. Windblown from fluvial channels.
12. Wild fires.
MAG plan, Table 9-a. The plan notes that several de minimis source
categories are already subject to control or will be controlled in the
future. MAG plan, p. 9-12.
We propose to find that the MAG plan has not excluded any source
categories that should be considered significant from its list of
significant source categories. The plan presents acceptable modeling to
evaluate the impact of various PM-10 sources and source categories on
PM-10 levels and to derive a comprehensive and conservative list of
significant source categories.
Our proposal here does not mean that we believe all the source
categories identified as significant in the MAG plan needed to be
considered significant for the purpose of evaluating BACM. We believe
that the MAG plan is conservative in its selection of significant
source categories, that is, it may have included more source categories
in its significant source list than are strictly needed. Thus our use
of negative wording in our proposed finding: no significant source
categories were excluded as opposed to only the significant categories
were included. In our 1998 FIP, we derived a narrower list of
significant sources based on more recent modeling than was used to
develop the list in the MAG plan. See 63 FR 15920, 15932 (Table 2 and
text).
2. Identification of Potential BACM
In preparing the list of candidate BACM, MAG reviewed our guidance
documents on BACM, other EPA documents on PM-10 control, as well as PM-
10 plans from other serious PM-10 areas in the West. It also evaluated
controls proposed during public comment. MAG plan, pp. 9-24 through 9-
29.
The MAG plan appropriately screened the list of candidate BACM to
eliminate measures that did not apply to significant source categories
in the area, were technologically infeasible for the area because they
would not reduce PM-10 emissions, or duplicated other measures on the
list. The MAG plan also provides cost effectiveness estimates for each
of the candidate BACM. MAG plan, pp. 9-30 through 9-39.
We propose to find that the MAG plan identified and evaluated
potential BACM for the Maricopa area consistent with our guidance. As
we will discuss below in our evaluations of the implementation of BACM
for each significant source category, we do not believe that the MAG
plan left out any candidate BACM. We note that additional evaluation of
control measures was done as part of the most stringent measure
analysis. MAG plan, pp 10-25 & 10-26. Overall, the MAG plan presents
one of the most comprehensive lists of potential BACM ever produced.
3. Implementation of RACM and BACM and Inclusion of MSM for Each
Significant Source Category
In the following sections, we review the results of the MAG plan's
BACM analysis. To present these results, we have grouped the emission
generating activities that comprise the MAG plan's significant
categories slightly differently from the plan, e.g., we have addressed
separately construction activities and disturbed vacant lands which are
both included in the MAG plan's significant category of construction
site preparation.\9\ We have done this to make our evaluations of the
plan's provisions for the implementation of BACM and inclusion of MSM
clearer and thus, we believe, more understandable. However, despite the
method of presentation, we have addressed the MAG plan's provisions for
implementing RACM and BACM for each of the plan's significant source
categories.
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\9\ MAG plan uses this grouping despite the fact that disturbed
vacant lands include lands that are disturbed for reasons other than
construction activity.
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Also, because of the substantial overlap in the source categories
and controls evaluated for BACM and those evaluated for MSM, we present
our evaluation of the MAG plan's provisions for including MSM alongside
our evaluation of the provisions for implementing RACM and BACM for
each significant source category.
Finally, controls on a number of significant source categories are
found in MCESD's fugitive dust rules, Rule 310 and Rule 310.01. MCESD
has made extensive commitments to improve compliance and enforcement of
these rules to assure that they achieve the emission reductions
necessary for expeditious attainment. These commitments are an
important component of our finding that the MAG plan provides for
implementation of RACM and BACM and inclusion of MSM. We discuss them
at the end of this section.
a. Technology controls for on-road motor vehicle exhaust. This
category includes tailpipe and tire wear emissions of primary PM-10
from on-road motor vehicles. On-road motor vehicles include both
gasoline and diesel-powered passenger cars, light, medium, and heavy
duty trucks, buses, and motorcycles.\10\
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\10\ We will treat gasoline-and diesel-powered vehicles together
here to preserve to the extent practicable the significant source
groupings in the MAG plan; however, we believe they are in fact
distinct categories. Almost 95 percent of diesel PM-10 emissions
come from heavy-duty diesel trucks while 75 percent of gasoline PM-
10 comes from the family car, that is, light duty cars and trucks
(which include sports utility vehicles). See Table ORM-1 in the EPA
TSD section ``Implementation of BACM and Inclusion of MSM for On-
Road Motor Exhaust (Technology Standards).'' There is almost no
overlap in the controls for the family car and those for heavy duty
diesel trucks, key evidence that they are in fact distinct source
categories. See Table ORM-4 in the EPA TSD.
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[[Page 19973]]
The suggested technology-based measures for controlling emissions
from on-road motor vehicle exhaust fall into one of five categories:
new emission standards, inspection and maintenance programs, fuels,
programs to encourage alternative fueled vehicle usage, and programs to
accelerate fleet turnover. In total, the MAG plan considers 22
technology-based control measures. See MAG plan, Table 5-2. We believe
this list is complete and propose to find that the MAG plan evaluates a
comprehensive set of potential technology-based controls for on-road
motor vehicle exhaust emissions including the potentially most
stringent measures from other states.
For gasoline vehicles, Arizona has implemented one of the nation's
best and most comprehensive enhanced I/M programs including expanding
the program to areas surrounding Phoenix; has adopted its own Clean
Burning Gasoline program which mandates the use of either Phase II
federal reformulated gasoline or California reformulated gasoline;
offers generous tax credits and deductions for conversion of vehicles
to alternative fuels; and mandates federal, state, county, and
municipal governments to convert their fleets to alternative fuels. MAG
plan, pp. 7-2 through 7-24.
Arizona has instituted a heavy duty diesel I/M program, will
require pre-1988 HDDV registered in the Phoenix nonattainment area to
meet 1988 federal emission standards starting in 2004, has established
a voluntary vehicle repair and retrofit program to encourage
retrofitting and overhaul of heavy duty diesel engines to reduce
emissions, and has limited diesel sulfur content to 500 parts per
million (ppm). MAG plan, Chapter 7.
The California Air Resources Board's diesel fuel standards (CARB
diesel) is one of the few identified motor vehicle controls not adopted
by the State. The plan identifies this measure as a potential MSM. MAG
plan, Table 10-7. The MAG plan claims that the measure is unreasonable
on a cost basis. MAG plan, p. 9-46. We make no judgement on this claim
given the great uncertainty regarding the potential cost of
implementing CARB diesel in the Phoenix area. We do note that the State
has already adopted half of the CARB diesel standards, the 500 ppm
sulfur limit.\11\
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\11\ The other CARB diesel standard is a limit on the aromatic
hydrocarbon content of no more than 10 percent by volume. CARB, Fact
Sheet on California Diesel Fuel, March 1997.
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Under our proposed policy for MSM in extension requests, we believe
that we can find that the MAG plan provides for the inclusion of MSM to
our satisfaction absent the adoption and implementation of CARB diesel
because, based on information in the MAG plan, the on-road engine
category's contribution to nonattainment in the Phoenix area is
relatively low compared to other PM-10 dust sources and implementation
of CARB diesel would not advance the attainment date.
According to the MAG plan, the on-road motor vehicle category
contributes just 1.3 percent of the pre-control inventory in 2006,
compared to construction dust at 43.8 percent, paved road dust at 20.4
percent, unpaved road dust at 13.1 percent, and windblown dust at 8.7
percent. MAG plan, Table 8-3. Adoption of CARB diesel would generate a
total reduction of 0.8 mtpd in 2006. MAG plan, p. 10-37. It takes a 4
mtpd reduction to advance the annual standard attainment date one year
(the minimum needed because it is an annual standard), so reductions
from implementation of this measure are insufficient to advance the
attainment date. See section on RFP and Quantitative Milestones.
As noted before, Arizona has in place one of the nation's most
comprehensive programs to address on-road motor vehicle emissions. With
the additional measures in the MAG plan (including a more stringent
diesel I/M program and measures both encouraging and requiring diesel
fleet turnover) the overall mobile source program is strengthened and
goes beyond the existing program. Both strengthening and expanding
existing programs are key criteria for demonstrating the implementation
of BACM. See Addendum at 42013. Where the MAG plan has rejected
potential BACM, it provides a reasoned and acceptable justification for
the rejection.
The MAG plan identified just a few measures from other areas as
being more stringent than existing programs. These measures have either
been adopted or we have concluded that the measures need not be
included to assure the inclusion of MSM.
All the adopted BACM and MSM are already implemented, except for
one. The requirement that pre-1988 heavy duty diesel vehicles
registered in the nonattainment area meet 1988 federal emission
standards will not be implemented until January 1, 2004 in order to
provide sufficient lead time for modification or replacement of the
non-complying heavy duty diesel vehicles.
We, therefore, propose to find that the combination of on-road
motor vehicle technology controls and TCMs (described in the next
section) in the MAG plan provides for the implementation of RACM and
BACM and the inclusion of MSM for on-road motor vehicle exhaust.
b. Transportation control measures (TCMs) for on-road motor vehicle
exhaust and paved road dust. TCMs can reduce PM-10 emissions in both
the on-road motor vehicle exhaust and paved road dust source categories
by reducing vehicle miles traveled (VMT) and vehicle trips. They can
also reduce vehicle exhaust emissions through relieving congestion. Our
serious area PM-10 guidance requires that plans identifying on-road
motor vehicles as a significant sources must also evaluate the TCMs
listed in section 108(f) of the CAA. Addendum at 42013.
In our review, we have primarily assessed the MAG plan's provisions
for implementing RACM and BACM and including MSM through TCMs based on
the measures' effectiveness in controlling directly-emitted PM-10 from
vehicle exhaust. We have not assessed the plan based on the TCMs'
potential benefit in controlling PM-10 precursors such as
NO
In total, the MAG plan identifies 19 TCMs for consideration
including the CAA section 108(f) measures. The plan does not identify
any potentially more stringent TCMs from other areas. See EPA TSD
section ``Implementation of BACM and MSM for On-Road Motor Vehicle
Exhaust and Paved Road Dust (TCMs).'' We believe that this list is
complete and propose to find that the MAG plan evaluates a
comprehensive set of potential TCMs for on-road motor vehicle exhaust
emissions and the potentially most stringent measures from other
States.
Arizona has a long history of adopting and then enhancing programs
to reduce emissions from on-road motor vehicles by reducing vehicle
miles traveled,
[[Page 19974]]
vehicle trips, and/or congestion.\12\ The area has an employer trip
reduction ordinance which applies to employers of 50 or more, a public
outreach program to encourage people to reduce driving, programs to
improve bicycling and pedestrian travel, and an extensive program to
synchronize traffic lights. In most instances, these programs were
adopted and implemented as part of carbon monoxide and ozone control
programs, but they also reduce PM-10.
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\12\ These plans include the MAG moderate and serious area
carbon monoxide plans and MAG moderate area ozone plan.
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With the additional measures in the MAG plan (including additional
traffic light synchronization, transit improvements, and bicycle and
pedestrian facility improvements), the overall TCM program is
strengthened and goes beyond the existing program. See EPA TSD, Table
TCM-3 in section ``Implementation of BACM and MSM for On-Road Motor
Vehicle Exhaust and Paved Road Dust (TCMs).'' Both strengthening and
expanding existing programs are key criteria for demonstrating the
implementation of BACM. See Addendum at 42013. Where the MAG plan has
rejected potential BACM, it provides a reasoned justification for the
rejection.
All the adopted TCM BACM are already implemented or have on-going
implementation schedules because they are part of a on-going capital
improvement program (e.g., signal synchronization).
We propose to find that the combination of on-road motor vehicle
technology controls (described in the previous section) and TCMs in the
MAG plan provides for the implementation of RACM and BACM and inclusion
of MSM for on-road motor vehicle exhaust. We also propose to find that
the combination of TCMs and paved road dust measures (described in the
paved road section later in this preamble) provides for the
implementation of RACM and BACM and the inclusion of MSM for paved road
dust.
c. Nonroad engines. The non-road engine category covers a diverse
collection of engines, equipment and vehicles fueled by gasoline,
diesel, electric, natural gas, and other alternative fuels, including
outdoor power equipment, recreational equipment, farm equipment,
construction equipment, lawn and garden equipment, and marine vessels.
The suggested measures for controlling emissions from nonroad
engines fall into one of four categories: new emission standards,
programs to accelerate fleet turnover, programs affecting usage, or
fuels. In total, the MAG plan evaluates 8 measures in addition to clean
fuels measures for reducing PM-10 emissions from nonroad engines. We
believe that this list is complete and propose to find that the MAG
plan evaluates a comprehensive set of potential measures for nonroad
engines including the potentially most stringent measures from other
States.
We have adopted national emission standards for a broad range of
nonroad engines. These standards apply to nonroad engines sold in
Arizona and are the base, RACM-level, program for controlling emissions
from nonroad engines. The CAA preempts all states, except for
California, from setting independent nonroad emission standards. CAA
section 209(e). Other states, however, may adopt regulations identical
to California's regulations, provided they notify us and give
appropriate lead time, 2 years, for implementation. Section
209(e)(2)(B).
Arizona has committed to adopt California's non-road standards that
are more stringent than the federal standards. MAG plan, p. 7-42. In
addition, the State has established and is currently running a
voluntary retirement program for gasoline powered lawn and garden
equipment which is run by Maricopa County and a program to encourage
the use of temporary electrical power rather than portable generators
at construction sites. See MAG plan, pp. 7-41 and 7-43.
With the addition of these measures, the overall nonroad engine
program is strengthened and goes beyond the existing federal program.
See EPA TSD section ``Implementation of BACM and Inclusion of MSM for
Nonroad Engines.'' Both strengthening and expanding existing programs
are key criteria for demonstrating the implementation of BACM. See
Addendum at 42013. Where the MAG plan has rejected potential BACM, it
provides a reasoned justification for the rejection.
The MAG plan identifies CARB diesel as a potential MSM for non-road
engines but does not adopt it. MAG plan, Table 10-7. Under our proposed
policy for MSM in extension requests, we believe that we can find that
the MAG plan provides for the inclusion of MSM to our satisfaction
absent the adoption of CARB diesel because, based on information in the
MAG plan, the non-road engine category's contribution to nonattainment
in the Phoenix area is relatively low compared to other PM-10 dust
sources and implementation of CARB diesel would not advance the
attainment date.
The nonroad motor vehicle category contributes 4.8 percent of the
pre-control inventory in 2006, compared to construction dust at 43.8
percent, paved road dust at 20.4 percent, unpaved road dust at 13.1
percent, and windblown dust at 8.7 percent. MAG plan, Table 8-3.
Adoption of CARB diesel would generate a total reduction of 0.8 mtpd in
2006. MAG plan, p. 10-37. It takes a 4 mtpd reduction to advance the
annual standard attainment date one year (the minimum needed because it
is an annual standard), so reductions from implementation of this
measure are insufficient to advance the attainment date. See section on
RFP and Quantitative Milestones.
We, therefore, propose to find that MAG plan provides for the
implementation of RACM and BACM and inclusion of MSM for on-road motor
vehicle exhaust.
d. Paved road dust. Paved road dust is the largest source of PM-10
in the Maricopa area. It is fugitive dust that is deposited on a paved
roadway and then is re-entrained into the air by the action of tires
grinding on the roadway. Dust is deposited on the roadway from being
blown onto the road from disturbed areas; tracked onto the road from
unpaved shoulders, unpaved roads, or other unpaved access points;
stirred up from unpaved shoulders by wind currents created from traffic
movement; spilled onto the road by haul trucks; and carried onto the
road by water runoff or erosion.
The suggested measures for controlling emissions from paved road
dust fall into one of three categories: reductions in vehicle trips
(VT) and vehicle miles traveled (VMT), preventing deposition of
material onto a roadway and cleaning material off the roadway. We have
already discussed measures for reducing VT and VMT in the section on
TCMs above.
The MAG plan lists several potential BACM for paved road dust. It
also lists a number of potentially MSM from other areas. We believe
these lists are complete and propose to find that the MAG plan
evaluates a comprehensive set of potential controls for paved road dust
including the potentially MSM from other States.
Prior to the MAG plan, the cities and towns in the Phoenix area and
Maricopa County implemented a number of measures addressing paved road
dust. See MAG plan, Table 10-5. With the additional measures in the MAG
plan (described below), the overall control program to reduce paved
road dust is both strengthened and expanded beyond the existing
program. See EPA TSD section ``Implementation of BACM
[[Page 19975]]
and Inclusion of MSM for Paved Road Dust.'' Both strengthening and
expanding existing programs are key criteria for demonstrating the
implementation of BACM. See Addendum at 42013.
For the potential MSM, the MAG plan shows that these measures are
either adopted or are not in fact more stringent than existing Phoenix
area programs.
With the exception of the MSM for PM-10-efficient street sweepers
described below, all the adopted BACM for paved roads are already
implemented or have on-going implementation schedules because they are
part of a on-going capital improvement program (e.g., curbing). For the
reasons discussed below, we propose to find that the MAG plan provides
for the implementation of the PM-10 efficient street sweeper measures
as expeditiously as practicable, consistent with our proposed MSM
policy.
We, therefore, propose to find that the MAG plan provides for the
implementation of RACM and BACM and for the inclusion of MSM for paved
road dust.
Preventing deposition of material onto a roadway. Measures aimed at
preventing track out on a paved road include treating unpaved access
points, preventing track out from construction/industrial sites,
treating shoulders on paved roads, controlling emissions during
material transport (e.g., truck covers, freeboard requirements), and
preventing erosion onto paved roads.
The MAG plan includes each of these measures:
Unpaved access points: In the MAG moderate area plan, local
jurisdictions focused on requiring new connections to public paved
streets to be paved. MAG plan, p. 9-74. In the serious area plan, the
focus has shifted to addressing existing unpaved access points in
addition to preventing new unpaved access points while maintaining the
previous programs. Most public entities committed to stabilize unpaved
access points when a connecting road is built, improved or
reconstructed. See, for example, Glendale Commitment, ``Reduce
Particulate Emissions from Unpaved Shoulders and Unpaved Access Points
on Paved Roads.'' Some cities have made explicit commitments for
stabilizing existing access points without this prerequisite, such as
Gilbert and Mesa. We also anticipate that routine city/town/County road
paving and stabilization projects will result in controlling a number
of existing unpaved access points. These projects combined with
increased enforcement of track-out restrictions and additional PM-10
efficient street sweeping efforts should reduce paved road emissions
attributable to unpaved access points.
The only potential MSM that the MAG plan identifies for unpaved
access points are track out control requirements for construction
sites. See MAG plan, Table 10-7. We discuss these measures in the next
section.
Track out. Rule 310, sections 308.2(c) and 308.3 address dirt track
out from construction/industrial sites: All work sites that are five
acres or larger and all work sites where 100 cubic yards of bulk
materials are hauled on-site or off-site each day must control and
prevent track out by installing a track out control device. All work
sites must also clean up spillage or track out immediately when it
extends a cumulative distance of 50 linear feet or more; where track
out extends less than 50 feet, it must be cleaned up at the end of the
work day.
The MAG plan identifies, as a potentially more stringent measure
for track out, South Coast (Los Angeles area) Air Quality Management
District's Rule 403. MAG plan, Table 10-7. The plan concludes that the
two rules are reasonably similar in several respects, and where
differences exist, the relative impacts on control roughly balance
against each other. MSM Study, p. C-4.\13\ We agree. Both rules
emphasize prevention and rapid removal of track out. See EPA TSD
section ``Implementation of BACM and Inclusion of MSM for Paved Roads
Dust,'' Note 2.
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\13\ The ``MSM Study'' is the ``Most Stringent PM-10 Control
Measure Analysis,'' Sierra Research, May 13, 1998 found in Appendix
C, Exhibit 4 of the MAG plan.
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Unpaved Road Shoulders. As with unpaved access points, the MAG plan
demonstrates a shift to dealing with existing unpaved shoulders from
only preventing new ones. MAG plan, Table 9-11. Maricopa County has
committed to treat 100 miles of shoulders along existing paved arterial
and collector roadways with high volume truck traffic by 2003, in
addition to its annual capital improvement projects for paving or
treating unpaved shoulders. Maricopa County commitment, 1999 revised
measure 5. Other jurisdictions have also made commitments to treat
shoulders.
A.R.S. 9-500.04(3) and 49-474.01(4), adopted by the State
legislature in 1998, require the cities, towns and County of Maricopa
to develop and implement plans to stabilize targeted unpaved roads and
alleys and to stabilize unpaved shoulders on targeted arterials
beginning January 1, 2000. Although this legislation does not specify
how many shoulder miles to be controlled, we believe that the local
jurisdictions' efforts to meet this new legislation will result in the
control of unpaved shoulders where it is most needed.
Material Transport. Requirements for the control of PM-10 emissions
during material transport are found in Rule 310, sections 308.1 and
308.2. When hauling material off-site onto paved public roadways,
sources are required to: (1) load trucks such that the freeboard is not
less than three inches; (2) prevent spillage; (3) cover trucks with a
tarp or suitable enclosure; and (4) clean or cover the interior cargo
compartment before leaving a site with an empty truck.
The MAG plan identifies requirements for bulk material transport in
Imperial County Regulation VIII as a potential MSM. MAG plan, Table 10-
7. The plan concludes that MCESD's rule is equally stringent. We agree
because Rule 310's requirements for bulk material transport/hauling are
essentially the same as Imperial County's requirements.
Cleaning material off the roadway. Measures for cleaning material
off roadway are track out, erosion, and spill removal requirements and
road sweeping.
The MAG plan includes each of these measures:
Material spillage, erosion, or accumulation. Rule 310, section
308.2 and 308.3 address rapid clean up of track out from construction/
industrial sites. Rule 310.01, section 306 requires property owners/
operators to remediate erosion-caused deposits of bulk materials onto
paved surfaces. Erosion-caused deposits are to be removed within 24
hours of their identification or prior to resumption of traffic on the
pavement.
The MAG plan identifies South Coast's Rule 1186 and Mojave Desert's
Rule 403 as potential MSMs for material spillage, erosion, and
accumulation onto roadways. MAG plan, Table 10-7. In both cases, the
plan concludes that MCESD's rules are more stringent. We agree. MCESD's
rules require the clean up of more incidences of spillage, etc. than
does South Coast's rule. See EPA TSD, ``Implementation of BACM and
Inclusion of MSM for Paved Roads,'' Note 5.
Street sweeping. Most cities/towns and the County have on-going
street sweeping programs with variable sweeping frequencies. With some
exceptions, public entities implementing this measure have not
explicitly committed to increase their existing sweeping frequencies.
Phoenix,
[[Page 19976]]
for example, approved a program in 1996 to increase the frequency of
residential street sweeping to match the uncontained trash pick-up
schedule. Phoenix commitment, measure 97-DC-5. However, sweeping
frequency is appropriately evaluated in combination with other paved
road measures, because the emission-reducing potential of increased
sweeping frequency is closely associated with other factors. These
factors include whether the sweepers currently in use are PM-10
efficient (such that the act of sweeping does not cause increased
emissions) and whether the public entity has identified roads that tend
to experience higher silt loadings where more frequent sweeping is
likely to make an appreciable difference in PM-10 emissions. Because
sweeping frequency is among the criteria included in MAG's PM-10
efficient street sweeper solicitation (see below), we believe this
measure is largely incorporated into MAG's new program.
The MAG plan identifies as a MSM the PM-10 efficient street
sweeping provisions in South Coast Rule 1186. MAG plan, Table 10-7.
However, the plan's analysis pre-dates MAG's commitment for the
purchase and distribution of PM-10 efficient street sweepers and is no
longer current.
The MAG plan includes commitments by MAG, cities, towns and the
County for the purchase and use of PM-10 efficient street sweepers.
This commitment involves the allocation of $3.8 million in Congestion
Mitigation Air Quality (CMAQ) funds for the FY 2000-2004 Transportation
Improvement Program (TIP) to purchase PM-10 certified street sweepers
for the local jurisdictions to use. MAG has recommended an additional
$1.9 million CMAQ funds be allocated to purchase PM-10 certified street
sweepers in the FY 2001-2005 TIP. See MAG commitment, ``PM-10 Efficient
Street Sweepers.''
The funds allocated by MAG for this program should be sufficient to
replace approximately two-thirds of the 72 existing city/town/County
street sweepers.\14\ Each fiscal year in which CMAQ funds are allocated
for street sweepers, MAG will solicit requests for funding from cities,
towns and the County in the PM-10 nonattainment area. Funding requests
must identify by facility type (i.e. freeway, arterial/collector,
local) the number of centerline miles to be swept with the PM-10
certified units, expected frequency of sweeping, and average daily
traffic (if available). MAG will use this information to estimate the
emissions reduction associated with each sweeper request and rank the
requests in priority order of effectiveness for consideration in the
allocation of CMAQ funds. See MAG commitment, ``PM-10 Efficient Street
Sweepers.''
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\14\ Some street sweepers may be additions to, as opposed to
replacements of, existing equipment.
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In evaluating this program, we considered not only the number of
PM-10 efficient street sweepers to be purchased and distributed, but
whether the program incorporates use factors that influence emissions
reductions. The greatest emissions reduction benefit for this
mitigative measure will be achieved if the sweepers are used on a
frequent basis on roads with high silt loadings or significant visible
accumulations. Each public entity has a monetary incentive to compete
for the PM-10 efficient street sweepers, as the program is funded by
MAG with a low cost share (5.7 percent) requirement. Also, the new
street sweepers will either replace existing city-owned street sweeping
equipment or contracted out services, or be added to existing street
sweeper equipment/services. MAG's selection process includes PM-10
emissions reduction potential, based on the types of roads each
jurisdiction is targeting for sweeping and how frequently they will be
swept. This data will assist MAG in distributing the street sweepers to
local jurisdictions in a way that maximizes the regional air quality
benefits of the program. Plus, when the cities/towns/County are awarded
PM-10 efficient street sweepers, their submittals will incorporate use
factors that maximize emission reductions from this measure.
We believe that implementation of the PM-10 efficient street
sweeper program is as expeditious as practicable. The funding necessary
to purchase this equipment is available only over the course of several
fiscal years and the purchase of the PM-10 efficient street sweepers
can only proceed at the rate these funds become available.
South Coast's Rule 1186 requires any government or government
agency which contracts to acquire street sweeping equipment or services
for routine street sweeping on public roads that it owns and/or
maintains, where the contract date or purchase or lease date is January
1, 2000 or later, to acquire or use only certified street sweeping
equipment. The rule establishes street sweeper testing and
certification procedures. Unlike Maricopa's strategy, Rule 1186
requires that PM-10 efficient street sweepers be used whenever street
sweeping is contracted out as of January 2000, and it requires public
agencies to replace their existing street sweeping equipment with PM-10
efficient equipment by attrition.
MAG's PM-10 efficient street sweeper program is being funded over
the next 4 to 5 fiscal years, which may result in a greater number of
street sweepers distributed in a shorter time frame than could be
expected using South Coast's natural attrition approach. While it is
possible that some cities/towns in Maricopa may continue to contract
out for street sweeping services where PM-10 efficient sweepers may not
be used, most do not contract for street sweeping. Furthermore, due to
the fact that public entities will be competing for PM-10 efficient
street sweepers funded by CMAQ dollars with only a low cost share
requirement, we believe that the already limited reliance on contracted
out services in Maricopa County will lessen as new PM-10 efficient
equipment becomes available and that contractors will switch to PM-10
efficient equipment to meet new demand. In addition, MAG's program
ensures that the cities/town/County develop plans for how the street
sweepers will be used to maximize their emissions reduction potential.
We, therefore, believe that overall the Maricopa program is equivalent
to South Coast's Rule 1186.
e. Unpaved parking lots. This category includes emissions from re-
entrained road dust from vehicle traffic in unpaved parking lots and
windblown dust entrained from the disturbed surface of unpaved parking
lots.
There are two principle ways to control emissions from unpaved
parking lots: prohibit unpaved parking lots or treat the lot. MAG plan
identified both: a prohibition on unpaved haul roads and parking or
staging areas and surface treatment to reduce dust from unpaved
driveways and parking lots. MAG plan, Table 5-2. The MAG plan
identified one potentially more stringent measure from South Coast
which controls fugitive dust from parking areas on construction sites.
MSM Study, p. C-9 and 10. It did not identify any potential MSM for
non-construction site unpaved parking lots. We believe this list is
complete and propose to find that the MAG plan evaluates a
comprehensive set of potential BACM and MSM for unpaved parking lots.
Most local jurisdictions in Maricopa County identified ordinances
that require paving of new parking lots. In addition, MCESD Rule 310.01
requires owners/operators of an unpaved parking lot larger than 5,000
square feet to pave, apply dust suppressants, or apply gravel,
according to the applicable rule
[[Page 19977]]
standards/test methods. Section 303. Applicable standards include a 20
percent opacity standard, and an 8 percent silt content standard and/or
a 0.33 oz/square foot silt loading standard. Section 303.2. MCESD Rule
310 applies the same stabilization requirements to parking lots on
permitted facilities. Rule 310, section 302.1. Finally, many cities/
towns have treated their own parking lots or required treatment of
private lots below MCESD's thresholds.
In determining whether the MAG plan provides for the implementation
of BACM for unpaved parking lots, we are also specifically considering
whether the plan provides for the implementation of RACM for these
sources.\15\ In our FIP, we promulgated a RACM fugitive dust rule
applicable to unpaved parking lots in the Phoenix PM-10 nonattainment
area and thus it provides a starting point for determining whether the
MAG plan measures for unpaved parking lots meet RACM. It is not
necessary for the MAG plan measures to be identical to the FIP rule in
order to meet the CAA's RACM requirement, but only that they provide
for the implementation of RACM.\16\ However, if the submitted measures
for a particular source are identical to the FIP rule, we can determine
without further analysis that the MAG plan has provided for RACM for
that source.
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\15\ While a serious area PM-10 plan must provide for both the
implementation of RACM and BACM, in determining whether such a plan
provides for BACM implementation, we do not normally conduct a
separate evaluation to determine if the measures also meet the RACM
requirements of the CAA as interpreted by EPA in its General
Preamble. See 57 FR 13540. This is because in our serious area
guidance (Addendum at 42010), we interpret the BACM requirement, as
generally subsuming the RACM requirement (i.e. if we determine that
the measures are indeed the ``best available,'' we have necessarily
concluded that they are ``reasonably available''). See Addendum at
42012-42014. Therefore, a separate analysis to determine if the
measures also represent a RACM level of control is not necessary.
However, in this particular case, we are proposing to withdraw the
FIP rule in conjunction with our proposed approval of the MAG plan.
In order to do this, we must determine under CAA section 110(l),
that, among other things, withdrawing the FIP rule does not
interfere with the RACM requirements in the CAA.
\16\ The State may submit one or more control measures that
collectively achieve a RACM level of control for a particular
source, regardless of whether they apply the same strategy as our
FIP rule. Furthermore, EPA's guidance indicates that a RACM
evaluation includes considering ``the impact of the reasonableness
of the measures on the municipal or other governmental entity that
must bear the responsibility for their implementation.'' General
Preamble at 13541.
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MCESD requirements for unpaved parking lots found in Rule 310.01,
section 303 are the same in terms of source coverage and applicable
standards/test methods for unpaved parking lots as the FIP rule, with
the only difference being that Rule 310.01 applies county-wide while
the FIP rule applies strictly to sources located in the PM-10
nonattainment area. Rule 310.01 requirements are effective upon
adoption and were adopted on February 2000, such that the timeframe for
controls is equivalent to the FIP rule and is also as expeditious as
practicable. In light of the fact that Rule 310.01 requirements are the
same as the FIP rule requirements and MCESD's commitments to improve
compliance and enforcement of Rule 310.01, we propose that the MAG plan
provides for the implementation of RACM. Given additional MAG plan
city/town commitments that collectively increase the stringency of
control on unpaved parking lots, we propose that the MAG plan also
provides for the implementation of BACM.
South Coast Rule 403 requires sources to apply dust suppressants to
stabilize at least 80 percent of unstabilized surface area. Sources
must comply with a 0 percent opacity property line limit. The MAG plan
deems the respective requirements roughly equivalent to Rule 310. We
believe that the addition of a silt loading/content standard for
unpaved parking lots for sources covered under Rule 310 increases the
rule's stringency to be at least equivalent to that of South Coast Rule
403. We, therefore, propose to find that the MAG plan correctly
concluded that there are no more stringent measures in other State
plans or used in practice elsewhere that are applicable to the Phoenix
area.
f. Disturbed vacant lands. This category includes windblown
fugitive dust emissions from disturbed surfaces of vacant lands. On
vacant land, fugitive dust emissions are caused by virtually any
activity which disturbs an otherwise naturally stable parcel of land,
including earth-moving activities, material dumping, weed abatement,
and vehicle traffic. 63 FR 15919, 15937 (April 1, 1998).
The MAG plan includes three suggested measures for controlling
fugitive dust from vacant disturbed lands. The plan also identified
controls on weed abatement operations and off-road racing as potential
most stringent measures. We believe this list is complete and propose
to find that the MAG plan evaluates a comprehensive set of potential
BACM and MSM for disturbed vacant lands.
The MAG plan includes two MCESD rules that address BACM for vacant
lots. Rule 310 requirements apply to vacant lots located at permitted
facilities (including construction sites) and Rule 310.01 requirements
apply to nonpermitted sources.\17\ Rule 310 and Rule 310.01
requirements apply to both publicly and privately owned lots. Rule 310,
section 302.3 and Rule 310.01, section 301 and 302.
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\17\ Permitted sources include any facility permitted by MCESD
and are not limited solely to those facilities with earthmoving
permits. Rule 310, section 102.
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In determining whether the MAG plan provides for the implementation
of BACM for disturbed vacant land, we are also specifically considering
whether the Plan provides for the implementation of RACM for these
sources. See Footnote 15. In our FIP, we promulgated a RACM fugitive
dust rule applicable to disturbed vacant land in the Phoenix PM-10
nonattainment area and thus it provides a starting point for
determining whether the MAG plan measures for disturbed vacant lands
meet RACM. It is not necessary for the MAG plan measures to be
identical to the FIP rule in order to meet the CAA's RACM requirement,
but only that they provide for implementation of RACM. See footnote 16.
However, if the submitted measures for a particular source are
identical to the FIP rule, we can determine without further analysis
that the MAG plan has provided for RACM for that source.
Rule 310.01 requirements for vacant lots and open areas are
virtually identical to the Phoenix FIP rule's requirements for these
sources. Rule 310.01, however, is more broadly applicable. It covers
vacant lots and open areas located anywhere in Maricopa County, in
contrast to the Phoenix FIP rule, which only applies to lots in the
Maricopa County portion of PM-10 nonattainment area (located in the
eastern third of the County). Rule 310.01, sections 301 and 302. Unlike
the FIP rule, Rule 310.01 also applies to partially developed
residential, industrial, institutional, governmental, or commercial
lots in Maricopa County, and any tract of land in the Maricopa County
portion of the nonattainment area adjoining agricultural property. Rule
310.01, section 211.
Rule 310 requirements for vacant lots and open areas on permitted
sources are more stringent than those in Rule 310.01, in that Rule 310
requires stabilization of all inactive disturbed surface areas on
permitted facilities, regardless of their size. Rule 310, section
302.3. Rule 310 also contains requirements for weed abatement that
closely resembles the Phoenix FIP rule's weed abatement requirements,
except
[[Page 19978]]
that Rule 310's threshold for coverage is more stringent.\18\
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\18\ Rule 310 requires any earthmoving operation that disturbs
0.1 acre or more to have a dust control plan, including weed
abatement by discing or blading, whereas the Phoenix FIP rule weed
abatement requirements only apply to disturbances equal to or
greater than 0.5 acres. Rule 310, section 303.
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Vacant lots and open areas subject to Rule 310 and Rule 310.01 are
required to meet the same surface stabilization standards/test methods
as required in the Phoenix FIP rule.
In addition to requirements in Rule 310 and Rule 310.01, the MAG
plan contains commitments made by several cities and towns to address
vacant disturbed lots. For example, seven jurisdictions require or will
require stabilization of disturbed vacant lots after 15 days of
inactivity (as compared to Rule 310.01's 60-day compliance period); two
(2) prohibit dumping of materials on vacant land; and two (2) will
stabilize all city-owned vacant lots.
Because Rules 310 and 310.01 requirements are at least as stringent
as the FIP rule requirements and MCESD has committed to improve
compliance and enforcement of these rules, we propose that the MAG plan
provides for the implementation of RACM on disturbed vacant land.
Because these rules increase the number of lots subject to control thus
collectively increasing the stringency of control on vacant disturbed
lands, we propose that the MAG plan also provides for the
implementation of BACM.
For its MSM comparison, the MAG plan identifies measures in Clark
County (Las Vegas, Nevada) Rule 41 and South Coast Rule 403. See MSM
Study, pp. C-11 and C-16,17. The plan concludes that neither measure is
more stringent than the Maricopa measures because Rule 310 and 310.01
contain similar, equally, or more stringent requirements. We agree that
the MCESD's rules are equally or more stringent.
We, therefore, propose to find that the MAG plan correctly
concluded that there are no more stringent measures in other State
plans or used in practice elsewhere that are applicable to the Phoenix
area.
g. Unpaved roads. This category includes re-entrained dust from
vehicle travel on unpaved roads. There are three classes of unpaved
roads in the Maricopa nonattainment area: public roads, private roads
that are publicly maintained (also referred to as minimally-maintained
or courtesy grade), and private roads that are privately maintained.
The MAG plan includes three suggested measures for controlling
fugitive dust from unpaved roads: Surface treatment to reduce dust from
unpaved roads and alleys, traffic reduction/speed control plans for
unpaved roads; and prohibition of unpaved haul roads. MAG plan, Table
5-2. The MAG plan did not identify any other State's measures that are
more stringent than the ones already in the plan. We believe this list
is complete and propose to find that the MAG plan evaluates a
comprehensive set of potential BACM and MSM for unpaved roads.
In determining whether the MAG plan provides for the implementation
of BACM for unpaved roads, we are also considering whether the Plan
provides for the implementation of RACM for these sources. See Footnote
15. In our FIP, we promulgated a RACM fugitive dust rule applicable to
unpaved roads in the Phoenix PM-10 nonattainment area and thus it
provides a starting point for determining whether the MAG plan measures
for unpaved roads meet RACM. It is not necessary for the MAG plan
measures to be identical to the FIP rule in order to meet the CAA's
RACM requirement, but only that they provide for implementation of
RACM. See footnote 16. However, if the submitted measures for a
particular source are identical to the FIP rule, we can determine
without further analysis that the MAG plan has provided for RACM for
that source.
As discussed below, we propose to find that the MAG plan provides
for the implementation of RACM and BACM and the inclusion of MSM for
unpaved roads.
Surface treatment to reduce dust from unpaved roads and alleys. The
principle control for public unpaved roads and alleys is Rule 310.01,
section 304, which requires all publicly-owned unpaved roads and alleys
with 250 vehicles per day or more to be stabilized by June 10, 2000 and
those with 150 vehicles per day or more to be stabilized by June 10,
2004.
Several cities have commitments that go beyond the requirements of
Rule 310.01 for publicly-owned unpaved roads. For example, the City of
Phoenix committed to, and recently accomplished, paving all 80 miles of
its publicly-owned unpaved roads regardless of the level of vehicle
travel. Phoenix Commitment, Measure 98-DC-7. Other cities, such as
Tempe and Gilbert, have very few remaining miles of public unpaved
roads/alleys. See Tempe Commitments, Measure 98-DC-7 and Gilbert
Commitments, Measure 98-DC-7.
For private roads, Rule 310, section 308.6, requires that
easements, rights-of-way, and access roads for utilities (electricity,
natural gas, oil, water, and gas transmission) that receive 150 or more
VPD must be paved, chemically stabilized, or graveled in compliance
with the rule's standards.
Private unpaved roads are scattered throughout Maricopa County,
within both County and city jurisdictions. A survey performed for us of
unpaved roads in Maricopa County determined that the great majority of
identified unpaved road mileage consists of privately-owned roads that
receive minimal maintenance by the Maricopa County Department of
Transportation (MCDOT).\19\
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\19\ Pacific Environmental Services, ``Survey for Fugitive Dust
Emission Sources,'' April 15, 1999.
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MAG and MCDOT have committed to pave County minimal maintenance
roads within the nonattainment area that currently exceed 150 ADT and
meet criteria to become public highways, using $22 million from
Congestion Management/Air Quality and MCDOT funds.\20\ MAG Commitment;
Maricopa County Commitment, 1999 Revised Measure 17. This program will
pave an estimated 60 miles of unpaved roadways in fiscal years 2001-
2003 which is approximately 20 percent of the privately-owned,
publicly-maintained County-jurisdiction roads and 40 percent of vehicle
miles traveled on these roads. Maricopa County has also committed to
continue to evaluate other roads for funding when traffic levels
increase above 150 vehicle trips per day. Maricopa County Commitment,
1999 Revised Measure 17. We interpret this commitment to apply to any
private roads within County jurisdiction, whether they currently
receive minimal maintenance or not.
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\20\ Congestion Management/Air Quality (CMAQ) funds are federal
transportation funds awarded to certain nonattainment areas for
congestion management or air quality-transportation projects such as
paving unpaved roads.
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As the County evaluates roads for paving, it may make exceptions to
its commitment to pave roads with vehicle trips that exceed 150 ADT.
The County's evaluation process takes into account whether a road meets
the proper criteria to become a public highway and whether estimated
costs of paving are excessive (greater than $500,000 per mile).\21\
When MCDOT identifies a road that meets these criteria (i.e. the road
can be declared a public highway and
[[Page 19979]]
costs are not excessive), it will recommend that the Board of
Supervisors open and declare the road a public highway.
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\21\ A private road begins to bear other than local traffic
through extensions of other nearby public roads or the construction
of an indirect source that attracts external drivers using the road
as a short cut. See Maricopa County Commitments, 1999 Revised
Measure 17.
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Because BACM implementation properly takes costs into account, we
believe that MCDOT's criteria for selecting private roads to pave are
suitable in the context of a strategy to implement BACM and will result
in control of the great majority of high traffic unpaved roads.
Although available information on private roads in city jurisdictions
is limited, our existing information suggests that a typical privately
owned unpaved road has low ADT.\22\ As a result, we believe that the
vast majority of private unpaved roads do not need to be controlled in
order for us to determine that the MAG plan provides for the
implementation of BACM for unpaved roads for the annual standard.
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\22\ Among the over 100 segments of unpaved privately-owned and
maintained roads that were identified in the PES survey, the
contractor estimated, using aerial photographs, that only 6 of these
have ADTs that exceed 150. Tube counts, which are more accurate than
other methods to estimate ADT, were not conducted on these roads.
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Traffic reduction/speed control plans for unpaved roads. Some
jurisdictions committed to evaluate this measure. Two jurisdictions
committed to posting 15 mph speed limit signs on private and public
unpaved roads and access ways; one jurisdiction has posted 15 mph speed
limits in all alleys. See MAG plan, Table 10-9. Also, under Rule 310,
owners/operators of unpaved haul roads and utility roads who comply
with the rule by limiting vehicle trips to 20 per day, must also limit
vehicle speeds to 15 mph. While speed limit controls are only being
implemented to a limited extent, we believe the plan measures to pave
or otherwise stabilize unpaved roads in the Phoenix PM-10 nonattainment
area establish the critical commitments for the implementation of RACM
and BACM. This is because road stabilization ensures emission
reductions whereas speed limits may or may not be observed.
Prohibition of unpaved haul roads. Rule 310 requires that unpaved
haul roads meet both a 20 percent opacity standard and a silt content
or silt loading standard. Rule 310, section 302.2. We propose to find
that this requirement is sufficient for the implementation of BACM for
these roads. We believe requiring compliance with both of these
standards ensures that the BACM applied will have a stabilizing effect.
Evaluation of unpaved road measures in other areas found none that
are more stringent than the measures for unpaved roads in the MAG plan.
MAG plan, Table 10-7. We agree and propose to find that there are no
other more stringent measures for unpaved roads than are already
included in the MAG plan.
Please see the TSD section ``Implementation of BACM and Inclusion
of MSM for Unpaved Roads'' for a more detailed discussion of our
proposed findings.
h. Construction sites and activities. Sources of fugitive dust
emissions at construction site sources include land clearing,
earthmoving, excavating, construction, demolition, material handling,
bulk material storage and/or transporting operations, material track
out or spillage onto paved roads (which we have addressed in the paved
road section), and vehicle use and movement on site (e.g., the
operation of any equipment on unpaved surfaces, unpaved roads and
unpaved parking areas). Windblown emissions from disturbed areas on
construction sites are also a source of PM-10. Construction operations,
which are mostly various forms of earthmoving, represent some 90
percent of the emissions in this source category.
The suggested measures in the MAG plan are actually various means
of improving compliance with controls as opposed to new controls for
construction sites. The controls for construction sites are found in
MCESD's fugitive dust rule, Rule 310, revised on February 16, 2000.
Rule 310's requirements, effective on February 16, 2000, apply to
any source required to obtain a permit under Maricopa County rules,
which includes earthmoving operations of 0.10 acre or more and sources
subject to Title V permits,\23\ Non-Title V permits, or General
Permits. In addition to rule requirements for fugitive dust sources
located at any permitted source, Rule 310 requires that a Dust Control
Plan (DCP) be submitted for any earthmoving operations of 0.10 acre or
more, and that the DCP be approved prior to commencing any dust
generating operation. The rule's definition of a dust generating
operation includes any activity capable of generating fugitive dust
including land clearing, earthmoving, weed abatement by discing or
blading, excavating, construction, demolition, material handling,
storage and/or transporting operations, vehicle use and movement, the
operation of any outdoor equipment or unpaved parking lots. For other
permitted sources, Rule 310 requires that a Dust Control Plan (DCP) be
submitted and approved prior to commencing any routine dust generating
activity, defined as any dust generating operation which occurs more
than 4 times per year or lasts 30 cumulative days or more per year.\24\
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\23\ Title V permits are operating permits required by Title V
of the Clean Air Act for major stationary sources and certain other
stationary sources.
\24\ This is in addition to the requirement to submit a DCP for
any earthmoving operation that disturbs 0.10 acre or more even if
the operation is subject to Title V or other permitting
requirements.
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Specific Rule 310 requirements include:
In order to comply with the rule's 20 percent opacity standard and
dust control plan requirements for implementing primary and/or
contingency control measures for earthmoving activities,\25\ sources
need to apply one or more controls, which in most cases includes
applying water or another dust suppressant before and during
operations. Inactive disturbed surfaces must be stabilized to meet at
least one of the rule's stabilization standards (e.g. visible crusting,
10 percent rock cover, etc.). Unpaved roads and unpaved parking lots
must also be stabilized to meet both a 20 percent opacity standard and
a silt content/loading standard.\26\ Test methods associated with
stabilization and
[[Page 19980]]
opacity standards are contained in Appendix C, which was submitted with
Rule 310.
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\25\ Earthmoving operations include cutting and filling,
grading, leveling, excavating, trenching, loading or unloading of
bulk materials, demolishing, blasting, drilling, adding to or
removing bulk materials from open storage piles, back filling, soil
mulching, landfill operations, or weed abatement by discing or
blading.
\26\ Unpaved roads must meet a 6 percent silt content standard
or, alternatively, a 0.33 oz/ft2 silt loading standard,
while unpaved parking lots must meet an 8 percent silt content
standard or, alternatively, a 0.33 oz/ft2 silt loading
standard.
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The February 2000 revisions to Rule 310 that have increased the
rule's stringency include the addition of specific work practice
standards, the addition of stabilization standards and test methods for
unpaved surfaces, and modifications to the opacity test method (adding
an alternative opacity test method for unpaved roads and unpaved
parking lots and modifying the opacity test method for other sources).
We believe that the new and/or revised standards/test methods provide
for a greater degree of control than under the previous SIP-approved
version of Rule 310.
In addition to these Rule 310 revisions, MCESD has made three
enforceable commitments to further strengthen requirements for
construction sites that must be met by July 2001. These commitments,
which all are part of Revised Measure 6 in Maricopa County's
commitments, are to: 1. Research and develop a standard(s) and test
method(s) for earthmoving sources, considering our field research, that
are enforceable and meet BACM requirements on stringency and source
coverage.
Currently, activities on construction sites must meet an opacity
standard of 20 percent. If research on the standards and test methods
find problems with the existing opacity standard's enforceability,
feasibility, or stringency for some or all earthmoving operations,
MCESD will revise the rule to modify the existing opacity test method
to address the problems as warranted or adopt a new standard(s) and
test method(s) to deal with any problems that cannot be addressed by
modifying the opacity test method;
2. Research, develop and incorporate additional requirements for
dust suppression practices/equipment for construction activities into
dust control plans and/or Rule 310;
3. Revise the sample daily recordkeeping logs for new and renewed
Rule 310 permits to be consistent with rule revisions and to provide
sufficient detail documenting the implementation of dust control
measures required by Rule 310 and the dust control plan. Distribute
sample log sheets with issued permits and conduct outreach to sources.
The first enforceable commitment addresses our concern that the
existing opacity standard and test method for earthmoving operations
may not always be sufficient to control construction site dust to BACM
levels. MCESD has already revised the opacity test method to deal
partially with this concern (see Rule 310, Appendix C), but we believe
that additional standards/test methods are needed to fully assure that
sources are effectively controlled. We have already sponsored a field
study to address this issue and are considering additional field work
in Summer, 2000. We believe that additional time is needed for Maricopa
County to investigate options in coordination with us, and then revise
the rule. Therefore, a commitment is the appropriate method of
addressing this issue.
The second enforceable commitment addresses our concern that dust
control plans (DCPs) lack specific criteria for dust suppressant
application. For example, a source engaged in grading or cut-and-fill
earthmoving for a multi-acre project may choose to comply with Rule 310
by applying water. However, neither the rule nor DCPs establishes
minimum criteria for the number of water trucks/water application
systems and water truck capacity for any given size construction site
or a ratio of earthmoving equipment to water trucks. The rule also does
not contain a pre-wetting requirement, although research may show this
to be necessary to successfully control dust on certain soil types.
Establishing criteria for dust control is complicated by variations
in soils, meteorological conditions, equipment size/use, project phase,
and level of activity. All these factors can impact the amount of water
(or other controls) needed to control fugitive dust on a particular
site on a particular day, making it difficult to establish criteria
that apply to all sites at all times. This explains why more time is
needed for MCESD to develop criteria to address a multitude of
circumstances.
The third enforceable commitment addresses our concern that while
Rule 310 currently contains an acceptable recordkeeping requirement, a
more specific recordkeeping requirement would help improve compliance.
Currently neither the rule nor DCPs specify what information should be
included in a daily log. MCESD has committed to revising and
distributing to permitted sources daily recordkeeping log sheets to
provide sufficient detail documenting the implementation of dust
control measures.
Based on our evaluation of revised Rule 310 and the additional
commitments made by MCESD, we propose to find that the rule and
commitments together include a comprehensive set of BACM level controls
for construction sites. The rule is comprehensive in scope in that each
dust source is subject to a set of requirements under Rule 310 (e.g.
storage piles, dirt trackout, haul truck loads, disturbed areas,
earthmoving operations). In addition, the Rule 310 requirements are
sufficiently stringent to provide for the implementation of RACM and
BACM, with the exception of certain aspects of the rule that are
addressed in the commitments made by MCESD. Thus, between the submitted
rule requirements and commitments, we propose to find that the MAG Plan
meets the CAA's RACM and BACM requirements for construction sites.
The MAG plan identifies potentially more stringent construction
site fugitive dust measures either in or under consideration for
inclusion in others SIP. See MSM Study, Table 1-2 and Table 3-1.
Most of the potential MSMs are provisions in South Coast fugitive
dust rule, Rule 403. The MAG plan indicates that each of the South
Coast and MCESD's rules are more stringent than the other in certain
respects. MAG plan, p. 10-35. The MAG plan acknowledges that Rule 403
contains more stringent control measure requirements than those imposed
by Rule 310. For example, Rule 403 requires that water be applied to
soil not more than 15 minutes prior to moving the soil and requires
open storage piles to be watered twice per hour or covered. However,
the MAG plan indicates that Rule 310's 20 percent opacity limit is
generally more restrictive than Rule 403's property line standard
because a 20 percent opacity fugitive dust plume typically disperses to
zero visibility within 50 feet downwind of a source. MSM Study, p. C-
12. The MAG plan concludes that, on balance, Rule 310 is equally
stringent compared to Rule 403's construction site requirements. We
agree with this conclusion with the caveat that we believe Rule 310
and/or dust control plans require additional control measures for dust
suppression. This caveat is addressed in the MAG plan's commitment to
research, develop and incorporate additional requirements for dust
suppression practices/equipment for construction activities into dust
control plans and/or Rule 310.
The MAG plan does not discuss any construction site measures from
other areas as potentially more stringent measures. Based on our work
with the Las Vegas area, we have identified requirements in Clark
County Health District permits that are potentially more stringent than
Maricopa County's
[[Page 19981]]
measures.\27\ These requirements include stand tanks on projects that
are 10 acres or more in size, an additional, separate water truck when
using a trencher or when screening, a separate water truck or pull
during landscaping, maintaining all stockpiles in a moist condition,
etc.
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\27\ These requirements are not in Clark County's fugitive dust
rule, but rather are required practices in dust control permits.
---------------------------------------------------------------------------
We propose to find that Rule 310's existing provisions and Maricopa
County's second enforceable commitment to research, develop and
incorporate additional requirements for dust suppression practices/
equipment into Rule 310 and/or DCPs are consistent with Clark County's
requirements.
We have also identified a requirement in Imperial County Regulation
VIII that is potentially more stringent than Maricopa County's
measures. Imperial County Regulation VIII requires that water be
applied 15 minutes prior to handling or transferring bulk material,
chemical/physical stabilization, or sheltering/enclosure of the
operation and transfer line. We propose to find that Maricopa County's
second enforceable commitment to research, develop and incorporate
additional requirements for dust suppression practices/equipment into
Rule 310 and/or DCPs is consistent with Imperial County's requirements.
For these reasons, we propose to find that the MAG plan provides
for the inclusion of the MSM applicable to the Phoenix area for
construction sites and activities.
i. Agricultural sources. The agriculture source category covers all
dust generating activities and sources on farms and ranches in the
Maricopa nonattainment area. These activities and sources include land
planning, tilling, harvesting, fallow fields, prepared fields, field
aprons, and unpaved roads.
Maricopa County is rapidly urbanizing with agricultural land being
converted into other uses at a rate of approximately 6,000 acres per
year. Cathy Arthur, MAG, December, 1997. Despite the conversion of
agricultural lands to other uses, agricultural sources are expected to
continue to contribute to PM-10 emissions for the foreseeable future,
especially in relation to the PM-10 24-hour standard.
The MAG plan identifies a number of potential BACM for agricultural
sources. MAG plan, pp. 5-66 thru 5-72 and pp. 6-12 through 6-13.
In 1998, Arizona passed legislation establishing an Agricultural
Best Management Practices (BMP) committee for the purpose of adopting
by rule by June 10, 2000, an agricultural general permit specifying
BMPs for regulated agricultural activities to reduce PM-10 emissions in
the Maricopa PM-10 nonattainment area. The Committee also is required
to adopt and implement an education program by June 10, 2000, and
affected agricultural sources are required to implement at least one
BMP by December 31, 2001. A.R.S. 49-457.A-H, M. On June 29, 1999, we
approved this legislation as a SIP revision meeting the requirement for
the implementation of RACM in 189(a)(1)(C) and at the same time
withdrew our commitment to adopt RACM controls for agricultural that we
included in the 1998 PM-10 FIP. 64 FR 34726.
The MAG plan relies on the State's commitment in A.R.S. 49-457 to
adopt and implement BMPs to meet the requirement to provide for the
implementation of BACM for agricultural sources. MAG plan, p. 7-156 and
Letter from ADEQ to EPA, September, 1998, submitting the commitment as
a SIP revision. The plan also relies on the statutory commitment to
meet the MSM requirement in CAA section 188(e). MAG plan, p.10-25.
Arizona's statutory BMP commitment is similar to the commitment we
made in our 1998 PM-10 FIP. 63 FR 41326 (August 3, 1998). As part of
the RACM demonstration in the FIP, we promulgated a commitment,
codified at 40 CFR 52.127, to ensure that RACM for agricultural sources
will be expeditiously adopted and implemented. For agricultural
sources, the State is using a similar strategy to address the RACM,
BACM and MSM requirements.
We propose to find that the State's commitment to adopt and
implement agricultural BMPs adequately addresses requirement to
implement BACM and include MSM. The potential BACM explicitly
identified in the MAG plan will be considered during the BMP
development process.
We have, beginning with the proposed rulemaking for our 1998 PM-10
FIP and culminating in Ninth Circuit litigation on both the FIP and our
SIP approval, explained at length our reasoning that a commitment to
implement PM-10 controls beginning in June 2000 for agricultural fields
and aprons in the Phoenix PM-10 nonattainment area rather than the
immediate implementation of fully-developed regulations for those
sources meets the RACM requirement in CAA section 189(a)(1)C). See 63
FR 15920, 15935-15936 (April 1, 1998); 63 FR 41332-41334; 63 FR 71817.
See also Brief for Respondents in Ober v. Browner, No. 98-71158, at 43-
59 (9th Cir., filed Oct. 2, 1998) (petition for review challenging
EPA's FIP commitment to adopt and implement RACM for agricultural
sources), and Brief for Respondents in Ober v. Browner, No. 99-71107,
at 16-40 (9th Cir., filed Aug. 26, 1999) (petition for review
challenging EPA's approval of the State's commitment to adopt and
implement agricultural BMPs as meeting the RACM requirement of the
CAA).
In the context of this proposed action, our reasoning in short is
that a legally binding commitment--embodied in the State statute
establishing a committee that is required to adopt a general permit
specifying BMPs and identifying specific deadlines for their
implementation--meets the statutory requirement in CAA section
189(b)(1)(C) since it is a ``provision to assure that best available
control measures'' are implemented by a fixed deadline. While in
preparing the FIP, we reviewed measures adopted by the South Coast for
the control of PM-10 emissions from agricultural sources, we concluded
that agricultural sources in the United States vary by factors such as
regional climate, soil type, growing season, crop type, water
availability, and relation to urban centers, therefore, each PM-10
agricultural strategy is uniquely based on local circumstances. As a
result, we could not, without further analysis, conclude that the South
Coast controls should be immediately implemented in the Maricopa area.
Furthermore, we determined that the goal of attaining the PM-10
standards in Maricopa County with respect to agricultural sources would
be best served by engaging all interested stakeholders in a joint
comprehensive process on the appropriate mix of agricultural controls
to implement in Maricopa County. We stated our belief that this
process, despite the additional time needed to work through it, will
ultimately result in the best and most cost-effective controls on
agricultural sources in the County.
While A.R.S. 49-457 does not use the term ``best available control
measure,'' its definition of BMPs is consistent with the criteria in
EPA's guidance. ``Best management practices'' are defined in A.R.S. 49-
457.N.3 as ``techniques verified by scientific research, that on a case
by case basis are practical, economically feasible and effective in
reducing PM-10 particulate emissions from a regulated agricultural
activity.'' The broad definition of BMPs in the Arizona statute
authorizes the BMP committee to adopt measures that will comply with
our definition of BACM.
[[Page 19982]]
Moreover, as noted above, the statute provides for BMP implementation
that begins with an education program by June 10, 2000 and culminates
in full implementation of the BMPs by December 31, 2001. \28\
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\28\ Of course, once adopted and submitted to EPA as a SIP
revision, the individual BMPs will have to be evaluated to determine
if they comply in their specifics with the BACM requirement. Here we
need only determine that the Arizona statute provides sufficient
authority to assure that BACM will be implemented by June 10, 2000.
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Similarly, we have concluded that the definition of BMPs in the
Arizona statute is broad enough to authorize the BMP committee to adopt
measures that meet the level of control in the requirement to include
MSM in CAA section 188(e) as we propose to interpret it in this
proposed action. In reviewing measures in other SIPs and/or that have
been adopted elsewhere, MAG determined that cessation of high wind
tilling and soil erosion control plans were the most stringent measures
available that had potential application for agricultural sources in
Maricopa County. MAG plan p. 10-47. These measures are included in
South Coast Rule 403 which requires PM-10 controls for all fugitive
dust sources, including agricultural sources. In December 1998, South
Coast adopted a set of conservation practices for agricultural sources
to use to reduce fugitive dust. These practices were developed in
consultation with affected stakeholder groups. See Guide to
Agricultural PM-10 Dust Control Practices. The BMP task force will
consider these measures during the development of the BMPs. MAG plan p.
10-47. After the BMPs and supporting technical documents are submitted
to EPA, we will review them to determine if their level of control is
as stringent as the South Coast rule or adequately justifies why such
level would not be feasible in the Maricopa area.
As discussed elsewhere in this TSD, we propose to interpret section
188(e) to require implementation of MSM as expeditiously as
practicable. For the reasons stated above, in our FIP, and in our
approval of the State legislation as meeting the RACM requirements of
the CAA, we conclude that the implementation schedule in the State
statute meets that test. Finally, we conclude that the commitment in
the State legislation meets the requirement that ``the plan include[s]
the most stringent measures * * *.'' Emphasis added.
j. Residential wood combustion. The residential wood combustion
(RWC) category includes emissions from the burning of solid fuel in
residential fireplaces and woodstoves as well as barbecues and
firepits.
Measures to control PM-10 from residential woodburning include
public education program, woodburning curtailment programs, retrofit
requirements and restrictions or bans on the installation of
woodburning stoves and/or fireplace. In total the MAG plan list 11
potential BACM and 10 potential MSM. MAG plan Tables 5-2 and 1-7. We
believe this list is complete and propose to find that the MAG plan
evaluates a comprehensive set of residential woodburning measures.
MCESD Rule 318, Approval of Residential Woodburning Devices,
establishes standards for the approval of residential woodburning
devices that can be used during restricted-burn periods. Maricopa
County's Residential Woodburning Restriction Ordinance provides that
restricted-burn periods are declared by the Control Officer when the
Control Officer determines that air pollution levels could exceed the
CO standard and/or the PM standard (150
MCESD revised the ordinance on November 17, 1999 to allow the
Control Officer to declare restricted-burn periods when the particulate
matter pollution levels could exceed the ``particulate matter no-burn
standard'' of 120
With these additional controls, the overall residential woodburning
restriction program is strengthened and goes beyond the existing RACM-
level program. Both strengthening and expanding existing programs are
key criteria for demonstrating the implementation of BACM. See Addendum
at 42013. Where the MAG plan has rejected potential BACM, it provides a
reasoned justification for the rejection.
The MAG plan identified a number of potential MSM for residential
wood combustion. Except for the adoption of a lower threshold for
calling no burn episodes, the plan does not provide for the adoption of
any of these measures but provides reasoned and acceptable
justifications for their rejection. Therefore, we propose to find that
the MAG plan provides for the inclusion of MSM.
k. Secondary ammonium nitrate. Secondary ammonium nitrate is formed
by a chemical reaction in the atmosphere between oxides of nitrogen
(NO
Two potential BACM were identified for ammonia nitrate control:
Reduce emissions of ammonia and nitrates from agricultural operations
and require animal waste management plans for farms/ranches with more
than 50 animals. The first measure involves tilling in of manure used
as fertilizer within 48 hours of application. MAG plan, Table 6-1,
measure 97-AG-3. The second measure would focus on reducing ammonia
emissions from livestock waste during the winter months when conditions
are most conducive to ammonium nitrate formation. MAG plan, Appendix B,
Exhibit 5, p. 5-70. For MSM, no measures were found that required
animal waste management plans for farms or ranches and no other
measures were identified. See MAG plan, Table 10-7. A large number of
measures that could reduce NO
Data from earlier studies indicate that ammonia emissions would
need to be reduced by 80 percent to have an appreciable impact on
ambient concentrations of ammonium nitrate. MAG plan, Appendix B,
Exhibit 5, p. C-1. Essentially all ammonia emissions in the inventory
are from livestock and not from the application of manure to
agricultural fields. As result, controls on the application of manure
are very unlikely to have any impact on PM-10 levels the Phoenix area
and therefore are not technologically feasible. \29\ The estimated
reduction in ammonia from
[[Page 19983]]
implementing waste management plans is 30 percent, far short of the 80
percent needed to show impact on PM-10 levels (MAG plan, Appendix B,
Exhibit 5, p. 5-72), so we also believe that this measure is currently
not technologically feasible.
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\29\ We consider a measure technologically feasible for an area
only if it has the potential to reduce emissions in manner that
reduces ambient concentrations in the area.
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Other than the on-road vehicle and nonroad engine categories, we do
not believe that there are any other sources of NO
Because the MAG plan includes an extensive number of measures for
controlling NO
l. MCESD's commitments to improve compliance and enforcement of its
fugitive dust rules. MCESD has committed to expanding and improving the
compliance and enforcement program for its fugitive dust rules. These
commitments are found in Maricopa County, 1999 Revised Measure 6,
adopted December 15, 1999. A narrative description of the commitments
and other program changes are found in Appendix IV, Exhibit 3 to the
MAG plan's modeling TSD. MCESD has also committed to continuing to
improve Rule 310 and Rule 310.01. These commitments are described in
section F.3.g. ``Construction Sites and Activities.''
These improvements include increased public outreach and education,
increased funding and staffing, increased inspection frequency, revised
enforcement policies, and commitments to program evaluations and
improvements. They address many of the program areas that are key to
improving compliance and we believe form a solid program for increasing
the effectiveness of the County's fugitive dust program.
Staffing. By the end of January, 2000, the inspection staff will
increase to eight inspectors, 1 supervisor, 1 aide and 2 enforcement
officers. By April, 2000, the County Attorney's office will hire an
attorney to expedite civil litigation and to assist with prosecuting
Class One Misdemeanor cases. A coordinator will be added to the Small
Business Environmental Assistance Program to assist smaller builders
and construction companies and to help develop and implement education
programs. In total, resources devoted to the fugitive dust program will
be 15 positions, a 25 percent increase over previous levels. This level
of staffing is in contrast to the less than 1 staff position devoted to
the program in 1996.
After reaching the committed staffing level, MCESD will review the
program in March 2000 to evaluate its effectiveness and the potential
need to add more staff.
Organization. A new enforcement section has been created under the
direct supervision of the MCESD Director/Air Pollution Control Officer
(APCO). This position streamlines enforcement by reducing senior
management review and approval of enforcement actions and allows
enforcement officers to submit directly to the APCO's desk all
enforcement actions requiring APCO approval.
In addition, inspectors will be located in two new regional offices
to provide quicker response times to dust-related complaints and allow
more time in the field.
Funding. Revenue for fugitive dust program is estimated at $1.12
million from annual earth moving permit fees, a $772,000 increase over
the previous level that is due to the permit fee increases adopted in
1998.
Inspection program. MCESD will develop by April, 2000 inspection
priorities for vacant lots and unpaved parking lots that consider lot
size and number of sources, with larger lots being inspected first and
smaller lots in succeeding years. A number of cities have municipal
programs to address these sources; therefore, the Department will
initially direct its inspections to cities lacking such programs. It
will also track the city plans that are required by State statute to
stabilize target unpaved roads, alleys and unpaved shoulders.
MCESD has also increased inspection rates and improved procedures
for permitted sources such as construction sites including:
Enforcement program. By April 2000, MCESD will revise it fugitive
dust enforcement policy to
Inspectors will handle certain predetermined citation category
violations and will be responsible for case development from observance
of a violation to filing of the actual citation in the justice court.
Having the inspectors handle routine cases will enable the enforcement
officers to work on resolving cases involving more serious and
complicated violations.
Public outreach/education. Public outreach and education consists
of staff training, educating the regulated parties, developing good
working relationships with other involved parties such as the cities,
and making the program more understandable. Increased education of both
inspectors and the regulated industry increases compliance.
Among the public outreach and education efforts will be:
Program evaluation and tracking. MCESD will track the number of
inspections, number and type of enforcement actions, amount of
penalties assessed, and amount of penalties collected. It will also
conduct mid-year reviews of the program in
[[Page 19984]]
September, 2000 and again in March 2001 to evaluate progress and future
needs.
G. Attainment Date Extension
1. Apply for an Extension
We interpret this requirement to mean that the State must apply in
writing for an extension and that the extension request must accompany
the SIP submittal containing the demonstration that the area will
attain by the most expeditious alternative date practicable. The public
must be provided reasonable notice and a public hearing on the request
before it is submitted.
MAG, as the lead air quality planning agency for the Phoenix
metropolitan area, formally requested an extension of the PM-10
nonattainment deadline to December 31, 2006 based on documentation in
Chapter 10 of the MAG plan and Appendix C, Exhibit 5 of the MAG plan.
MAG plan, p. 10-2. This extension request is an integral part of the
MAG plan and was subject to public hearing along with the rest of the
plan.
2. Demonstrate the Impracticability of Attainment by December 31, 2001
In order to demonstrate impracticability, the plan must show that
the implementation of BACM (as determined by our guidance) on
significant sources categories will not bring the area into attainment
by December 31, 2001.
To demonstrate the impracticability of attainment by 2001, the MAG
plan derived from the air quality modeling a change in PM-10
concentrations per change in emissions using the modeled concentration
for the year 2006 and observed concentration for the year 1995 at
Greenwood monitor and the overall change in emissions between the two
years. MAG plan, p. 8-10. Using this information, the plan estimates
that the annual concentration in 2001 will be 52.21
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\30\ In addition the MAG plan shows that implementation of
controls on the de minimis source categories would not produce
enough emission reductions to show attainment in 2001. MAG plan, p.
9-11.
---------------------------------------------------------------------------
Based on our analysis of control measures in the MAG plan as
described in the preceding sections, we propose to find that the MAG
plan provides for implementation of BACM as required by CAA section
189(b)(1)(C). Based on the modeling analysis in the plan, we also
propose to find that the MAG plan also demonstrates that attainment by
2001 is impracticable with the implementation of BACM.
3. Complied With Commitments and Requirements in the SIP
We interpret this criterion to mean that the State has implemented
the control measures in prior SIP revisions it has submitted to address
the CAA requirements in sections 172 and 189 for PM-10 nonattainment
areas. It does not include measures being approved in this action.
The two SIP revisions that Arizona has submitted to address PM-10
are the 1991 MAG moderate area plan and the 1997 microscale plan.
The 1991 MAG plan includes a broad range of measures to address PM-
10 including controls for constructions sites, paved road, unpaved
roads, unpaved parking areas, vacant lots, and woodburning. The plan
also included reasonably available control technology for stationary
sources and a wide range of transportation control measures. The
implementation of the measures in this plan are described in the MAG
plan at pp. 10-10 to 10-25. The principal controls in this plan were
Rule 310 and the County woodburning ordinances. The plan also contained
a large number of commitments from the local jurisdictions to various
measures. Most of the measures represented ``business as usual''
actions by the jurisdictions to do infrastructure (e.g., road)
improvements, to implement existing building codes or take actions
already underway for the carbon monoxide plan. MAG plan, pp. 10-13
through 10-24.
The 1997 Microscale plan focused on fugitive dust sources such as
construction sites, vacant lots, unpaved roads, unpaved parking lots,
and agriculture. The principal controls in this plan were improvements
to the implementation of Rule 310 and coordination with the cities to
improve fugitive dust control. Implementation of the measures in the
Microscale plan are discussed in Maricopa County commitments, 1998
Revised Measure 6.
From available information in the MAG plan, we believe that the
commitments and requirements in these plans have been met. We,
therefore, propose to find that the State has complied with the
requirements and commitments in its implementation plan.
4. Include the Most Stringent Measures
The MAG plan excluded no source categories of directly-emitted PM-
10 from its MSM analysis instead simply started its evaluation of MSM
by identifying candidate measures for any source category of PM-10
present in the Phoenix area. MAG plan, p. 10-25. To identify candidate
MSM, MAG's contractor Sierra Research interviewed people knowledgeable
about PM-10 controls, reviewed the documents used to develop the
candidate list of BACM and obtained copies of current air quality
control measures from most other States including both SIP and non-SIP
measures. MSM Study, p. 1-2.
After a comprehensive list of candidate MSM was developed, each
measure was screened against the corresponding Maricopa measure to
identify those with more restrictive emission limitations, more
extensive list of affected sources, fewer exemptions, and/or one or
more substantive regulatory provisions not found in the Maricopa
measure. The remaining MSM were grouped by source category and were
either included in the plan or a reasoned justification for rejecting
the measure was provided. MSM study, Table 3-1 and MAG plan, p. 10-46.
We propose to find that the MAG plan demonstrate to our
satisfaction that it includes the most stringent measures that are
included in the implementation plan of any State, or are achieved in
practice in any State, and can be feasibly be implemented in the
Phoenix area.
We have discussed identification and adoption of MSM and the
rejection of any MSM for each category deemed significant for BACM
earlier in this preamble. The MAG plan identifies three MSMs for
categories considered de minimis in the BACM analysis. These categories
are cattle feed lots, incinerators, and charbroilers.
Cattle feed lots: MCESD Rule 310.01 requires that owners/operators
of commercial feedlots and/or livestock areas apply dust suppressants,
apply gravel, or install shrubs and/or trees within 50 to 100 feet of
animal pens. The MAG plan identifies South Coast Rule 1186 requirements
for livestock operations as a potentially more stringent requirements
than Rule 310.01. However, the two rules control different sources at
commercial feedlots/livestock areas. South Coast Rule 1186 requires
controlling unpaved roads and hay grinding at dairy and horse farms but
does not address fugitive dust emissions from disturbed open areas.
MCESD Rule 310.01 controls fugitive dust emissions from disturbed open
areas at dairies and cattle lots, but not unpaved roads and hay
grinding.
In the Maricopa County PM-10 nonattainment area, there is only one
cattle feedlot and less than half the
[[Page 19985]]
number of dairies compared to those subject to South Coast Rule 1186.
Similar to South Coast, unpaved roads at dairies are low travel (10 to
20 ADT) and represent a very small source of emissions in the Phoenix
area and controls on them would not advance the attainment date. We,
therefore, believe we can find that the MAG plan provides for the
implementation of MSM to our satisfaction without Rule 1186 provisions
for unpaved roads at cattle feed lots. In Maricopa County, hay grinding
activities occur primarily at feed mills (as opposed to dairies) which
are permitted sources and thus already subject to control requirements.
Incinerators: The MAG plan identifies Clark County's Rule 26 as
having a more stringent opacity limit than MCESD's Rule 313. Clark
County limits opacity from existing incinerators to 5 percent while
Maricopa's limit is 20 percent. MAG plan, Table 10-7. Incinerators are
a very small source in the Phoenix nonattainment area. In 1994 there
were 32 incinerators that together emitted 2.56 metric tons per year
(7.1 kg per day). 1994 Regional PM-10 Inventory, p. 4-17. Because
incinerators are so small a source and controls on them would not
advance the attainment date, we propose to find that the MAG plan
provide for the inclusion of MSM to our satisfaction without including
Clark County's opacity limit for incinerators.
Charbroiling: Emissions from charbroiling and frying meat are
estimated to 0.6 mtpd or 227 mtpy. 1994 Regional PM-10 Inventory, p. 4-
25. This is 0.4 percent of the daily directly-emitted PM-10 inventory
in 1994 and 0.4 percent of the annual inventory in 1994. MCESD has
committed to develop a new rule to require existing and new chain-
driven and underfired charbroilers, typically found in restaurants
specializing in grilled meat products, to be equipped with emission
control equipment. South Coast is developing a new rule to deal with
underfired charbroilers and MCESD will wait until South Coast completes
its rulemaking to adopt this measure. MCESD is projecting adoption of
its rule in Spring, 2001. Maricopa County commitments, Revised Measure
23. We propose to find that implementation of this rule is expeditious.
Waiting on South Coast to complete its rulemaking, which will establish
control requirements for underfired charbroilers, is appropriate given
that the South Coast rule when adopted will set the standard for
control on these types of charbroilers.
5. Demonstrate Expeditious Attainment
For the reasons discussed below, we propose to find that the MAG
plan demonstrates attainment by the earliest date practicable after
December 31, 2001 as required by section 189(b)(1)(A)(ii) of the CAA.
We also propose to find that the attainment demonstration relies on
control measures that either are approved or are being proposed for
approval and meet our SIP enforceability criteria; that the emissions
estimates assigned these measures in the attainment demonstration are
reasonable; and the measures are being implemented on a schedule that
is as expeditious as practicable and will result in attainment by the
earliest practicable date. See discussion below.
a. Air quality modeling. A modeled attainment demonstration for the
PM-10 annual standard should first estimate the temporal and spatial
distribution of PM-10 and PM-10 precursor emissions that result from
the adopted control measures by the attainment date. It should then
simulate the ambient air concentration of these emissions in an air
quality model and show that all locations within the nonattainment area
have annual average PM-10 concentrations below the level of the annual
PM-10 standard of 50
To provide context for our evaluation of the air quality modeling
in the MAG plan, we will first briefly describe the steps in developing
a modeled attainment demonstration and how the MAG plan performed each
step.
Step 1. A modeling base case is developed to replicate PM-10
concentrations for specific recent days by simulating the emissions and
meteorology that occurred for those days, by hour and by location
throughout the area being modeled (that is, the model domain). For some
input parameters, alternative plausible values are tried in a
diagnostic process to ensure that the model is performing in a
physically reasonable way. PM-10 concentrations from the model output
are compared to monitored values to evaluate the performance of the
model.
The base case for the MAG plan consisted of the application of the
urban airshed model with the limited chemistry module (UAM/LC) to each
of 65 days during 1995. The results from modeling each of these days
are then averaged together to get the modeled annual PM-10
concentration. 1995 was used as the base year because an intensive
inventory and monitoring study was performed during it; the 65 days
coincided with the available PM-10 24-hour average monitoring data,
which are collected once every 6 days. During 1995 the peak monitored
annual PM-10 concentration was 60.01
---------------------------------------------------------------------------
\31\ The MAG TSD is the ``Revised Technical Support Document for
Regional PM-10 Modeling in Support of the Revised MAG 1999 Serious
Area Particulate Plan for PM-10 for the Maricopa County
Nonattainment Area,'' MAG, February 2000 found in Appendix A,
Exhibit 7 of the MAG plan.
---------------------------------------------------------------------------
Step 2. After the base case model is developed, emissions are
projected into the future. Projections are based on particular
facilities's expansion plans, business and socioeconomic projections,
and projections of the effect of changing technology and of the control
measures that are already in place. The model simulation is repeated
with these future emissions but with the same meteorological inputs as
before. This simulation shows how a day meteorologically conducive to
high PM-10 concentrations will look in the future if no new controls
are implemented. The resulting modeled concentrations can be used to
derive an estimate of the additional emission reductions needed to
attain the air quality standard.
For the MAG plan, emissions are projected to 2006 (which MAG found
to be the earliest practicable attainment year). Before additional
controls, the 2006 future peak PM-10 annual average was simulated to be
86.72
Step 3. The effect of control measures on ambient concentrations
are simulated by changing the model emission inputs for future years to
reflect higher implementation rates or larger emission reductions from
additional controls. Additional measures are tried if PM-10
concentrations are still above the standards.
Attainment is demonstrated when sufficient emission reductions are
in place so that modeled concentrations in every grid square are below
the standard.
MAG showed that with additional controls, the peak annual PM-10
concentration in 2006 is 49.70
[[Page 19986]]
demonstrating attainment. MAG plan, p. 8-12.
In evaluating the air quality modeling in the MAG plan, we reviewed
the choice of models; the selection of episodes to model, the selection
of the modeling domain and grid resolution, the methods of preparing
wind, temperature, and mixing height fields data; the selected initial
and boundary conditions values; the modeling emission inventories; the
procedures for and results of quality assurance, diagnostic testing and
sensitivity testing; and selected modeling performance goals and model
results vis a vis these goals. We have found them all generally
acceptable. See our detailed evaluation in EPA TSD section
``Demonstrate Attainment by the Most Expeditious Alternative Date
Practicable after December 31, 2001.''
The modeling performed for the MAG plan is as sophisticated as any
that has been performed for a PM-10 SIP. While there are several
problems associated with the model's performance for secondary
particulates and several other shortcomings of the modeling and its
documentation, the dominance of the contribution of primary
particulates from fugitive dust to PM-10 concentrations in the Phoenix
area obviates these concerns. At worst the MAG plan's modeling is akin
to modified rollback, an approach that is acceptable under EPA modeling
guidance for PM-10. We therefore propose to approve the modeling for
the annual NAAQS because it provides a credible demonstration that the
credited control measures will provide for attainment of the annual
standard by 2006.
b. Control measures relied on for attainment. For demonstrating
attainment, the MAG plan relies on reductions in directly-emitted PM-10
from 12 measures. MAG plan, Table 8-2. We have listed each measure; the
rule, commitment or state statute through which it is implemented, and
its emission reductions in Table 1-1.
We have evaluated each of these measure to ensure that it meets our
SIP enforceability criteria. These criteria ensure that the measure's
compliance requirements'applicability, performance standards,
compliance schedule, and monitoring methods--are clear.
We have also evaluated the emission reductions credited to each
measure to ensure they are reasonable. In particular, we looked at the
reduction estimates for Rules 310 and 310.01.
The MAG plan assumes an incremental increase in rule effectiveness
for these rules from 66 percent in 1998 to 80 percent in 2006. MAG TSD,
Appendix IV, Exhibit 1, Committed Measure 1. Rule effectiveness (RE)
accounts for emission reductions lost because of noncompliance, control
equipment downtime, failure to apply adequate controls, or failure to
use control equipment properly. One hundred percent rule effectiveness
is the ability of a regulatory program to achieve all the emission
reductions that could be achieved by full compliance with the
applicable regulations at all sources at all times.
We have established policies on applying rule effectiveness factors
for both base year and projected year inventories of volatile organic
compounds (VOC), a precursor to ozone. See General Preamble at 13503
and ``Rule Effectiveness Guidance: Integration of Inventory,
Compliance, and Assessment Applications.'' USEPA, OAQPS, EPA-452/R-94-
001, January 1994, (RE Guidance). In general, we encourage states to
derive local category-specific RE factors. If there are no such local
RE factors, we require the use of an 80 percent effectiveness default
value in VOC inventories. General Preamble at 13503.
We have not established any explicit guidance for applying RE to
particulate matter sources. We know, however, that PM sources like VOC
sources are not in full compliance with applicable rules at all times;
therefore, some RE factor needs to be applied. For this rulemaking, we
have applied the existing Agency RE guidance for VOC sources to
emission reduction estimates for Rule 310 and Rule 310.01.
The items that influence compliance with a rule and thus the
appropriate RE factor are the clarity of the rule, its compliance
requirements and the complexity of the controls required by the rule;
the source's actions; and the implementing agency's actions. See RE
Guidance, pp. Table 1-1 and Appendix C.
Under our guidance, a state is allowed and required to use a 80
percent RE factor absent evidence to the contrary. General Preamble at
13503. In this case,
[[Page 19987]]
the evidence that we have is that compliance for Rule 310 was below
this level as of early 1998. MAG, with concurrence of MCESD, assumed a
30 percent compliance rate for the Rule 310 in the 1995 base year
modeling. Inspections by MCESD in early 1998 indicated that the
compliance rate with the rule was 66 percent. MAG TSD, Appendix II,
Exhibit 6, ``Documentation on Assumption of Rule 310 Control Efficiency
and Compliance Rate.''
Over the last few years, MCESD has made substantial changes to its
fugitive dust control program, many designed to improve compliance.
MCESD has also committed to a number of additional changes which we
have described earlier. We believe that an 80 percent rule
effectiveness in 2006 is appropriate given these changes and MCESD's
commitments to improve compliance with Rules 310 and 310.01. These
improvements cover rule and test method revisions, increased public
outreach and education, increased funding and staffing, increased
inspection frequency, revised enforcement policies, and commitments to
program evaluations and improvements. They address many of the program
areas that are key to improving compliance.
In our TSD (in the section ``Extension Request-Demonstrate
Attainment by the Most Expeditious Alternative Date Practicable after
December 31, 2001''), we have compared the MCESD's fugitive dust
program in 1996 to the program that will be in place by 2006 based on
MCESD's commitments in the MAG plan and its actions to date. This
comparison clearly shows the scope of improvements to the MCESD's
fugitive dust program and supports our proposed finding that an 80
percent RE in 2006 for Rule 310 and Rule 310.01 is appropriate.\32\
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\32\ The cities and towns in Maricopa County are also increasing
their efforts to address fugitive dust sources, such as unpaved
parking lots and disturbed vacant lots. These efforts also support
an overall 80 percent rule effectiveness.
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Finally, we have looked at the implementation schedule for each
measure to assure that the MAG plan provides for expeditious
implementation. Except for paving of some unpaved roads, adoption of
the charbroiler rule, heavy duty diesel standards, and the purchase and
deployment of the PM-10 efficient street sweepers, all the measures
relied on in the attainment demonstration are currently in effect.
However, attainment of the PM-10 annual standard in the Phoenix
area depends on a high level of compliance with MCESD's fugitive dust
rules. The MAG plan assumes this level increases from 66 percent in
1998 to 80 percent in 2006. MAG TSD, Appendix IV, Exhibit 1, Committed
Measure 1. This level of compliance depends in turn on education of the
regulated community and increased enforcement modifying source
behavior. Both of these take time to effect, therefore, we believe that
it is reasonable to allow a period of time to achieve a high level of
compliance with these rules. We thus believe that the emission
reductions are being achieved as expeditiously as practicable.
6. Other Factors That EPA may Consider
CAA section 188(e) list five additional factors that we may
consider in deciding whether to grant an extension and the length of
that extension.
The MAG plan provides information addressing each of the factors in
Chapter 10 of the plan. We have already proposed to determine that the
MAG plan provides for the implementation of RACM and BACM, includes the
MSM, and attainment of the annual PM-10 standard by the earliest
practicable date of December 31, 2006. In the next section, we will
also propose to find that the plan provides for reasonable further
progress. Nothing in the additional information presented on the five
factors suggest that granting an extension of the attainment date for
the Phoenix area to 2006 is inappropriate.
a. Nature and extent of nonattainment. Over the past 5 years,
violations of the annual standard have occurred routinely at three
sites (MAG plan, Table 10-11):
1. Greenwood, an urban site heavily impacted by transportation
sources,
2. Chandler, an urban fringe site heavily impacted by fugitive dust
sources such as construction and agriculture, and
3. Salt River, a site heavily impacted by industrial sources.
Areas similar to the first two sites can be found throughout the
Phoenix nonattainment area, so we would expect that there are similarly
elevated PM-10 levels throughout the Phoenix area; therefore, controls
need to be uniformly implemented throughout the nonattainment area, a
task that generally requires longer to achieve than implementing
controls in few localized areas.
b. Types and numbers of sources or other emitting activities.
Primary contributors to elevated PM-10 levels are fugitive dust sources
including paved road dust, unpaved roads, construction activities,
disturbed vacant lands, unpaved parking lots, and agricultural sources.
MAG plan, p. 10-51. These sources are ubiquitous in the nonattainment
area and collectively number in the thousands. (For example, MCESD
issued 2500 construction permits in 1999; we mailed 50,000 letters to
owners of vacant lots in the nonattainment area; there are 12,000 miles
of roadway in the nonattainment area.)
c. Population exposure to concentrations above the standard. The
MAG plan estimates population exposure to elevated levels of PM-10
(both annual and 24-hr) to be from 78,000 to 163,000 (1995 figure), p.
10-13. This population exposure is calculated using estimates of
disturbed land versus population in subareas of the nonattainment area.
According to this calculation, 84 percent of Maricopa's population
lives in areas where 10 percent or less of the land is open. MAG plan,
Table 10-13. This exposure number does not seem to include populations
exposed to dust from paved and unpaved roads and therefore may
underestimate overall population exposure. However, the plan does
provide for implementation of RACM, BACM, and MSM on disturbed land
(including construction) and paved and unpaved roads with much of the
emission reductions being achieved in the first few years, all these
factors will reduce population exposure as quickly as practicable.
d. Presence and concentration of potentially toxic substances in
the particulate. The primary source of airborne cancer risk in the
Maricopa area is internal combustion engine exhaust from both on- and
non-road engines. This risk is from all pollutants emitted from these
sources (gaseous and particulate). MAG plan, p. 10-61. The MAG plan
concludes that the cancer risk in the Phoenix area is comparable to
that in California cities, p. 10-61. The MAG plan and other Arizona
programs (e.g., cleaner burning gasoline, national emission standards
for non-road engines) target emissions from on- and non-road engines.
Almost all of the PM-10 emission reductions in the out years of the
MAG plan (2003 and later) are and need to be from fugitive dust sources
in order to show attainment of the annual PM-10 standard and not fron
on- and non-road engines; therefore, extending the attainment date does
not affect the degree of public exposure to the major source of toxic
risk because shortening the extension would not accelerate controls on
the major source of toxic risk, on- and nonroad engines.
e. Technological and economic feasibility of controls. Fugitive
dust sources dominate the emission inventory in the Maricopa
[[Page 19988]]
nonattainment area. Controls for these sources are well known (paving,
wetting surfaces, etc.) and have been adopted; however, the number of
sources and nature of sources make education and outreach necessary to
assure full compliance with those controls. In addition, costs for
paving roads, purchasing street sweepers, and other capital
improvements necessary to reduce PM-10 emissions are high and necessary
funds are only available over a number of years. These factors
generally support a longer time frame for attainment.
7. Conclusion on Extension Request
Based on our review of the MAG plan and our proposed determination
that it meets the requirements necessary for granting an extension of
the attainment date under CAA section 188(e), we are proposing to grant
a five-year extension of the serious attainment date for the Phoenix
PM-10 serious nonattainment area from December 31, 2001 to December 31,
2006.
H. Reasonable Further Progress (RFP) and Quantitative Milestones
We propose to find that the MAG plan provides for RFP and meets the
quantitative milestone requirements of the Act.
1. Reasonable Further Progress
The MAG plan provides for annual progress so that emissions levels
in each year from 1995 to 2006 that are at or below the level needed to
maintain linear progress toward attainment. It demonstrates that
regional PM-10 emission levels will drop from 191 mtpd in 1995 to 130
mtpd in 2006 with two-thirds of the reduction occurring before 2001.
MAG plan, Figure 8-4. Total regional emissions decrease annually at a
rate of approximately 6.5 mtpd per year from 1995 through 2001 and 4.4
mtpd per year from 2002 to 2006. The assumptions that underlie the RFP
demonstration regarding control measures' implementation and
effectiveness are reasonable.
The plan does not provide emission reduction information for each
year between the base modeling year of 1995 and the attainment year of
2006. We do not believe that this level of detail is necessary or
meaningful. The principal control measures in the plan (such as
improving compliance with the fugitive dust rules, progressive paving
of unpaved roads, and annual replacement of part of the street sweeper
fleet with PM-10 efficient units) produce year to year incremental
increases in emission reductions sufficient to meet the statutory
requirement for RFP. See MAG plan, Figure 8-4 and EPA TSD, Figure RFP-
1. Therefore, we propose to find that the MAG plan provides for ``such
annual incremental reductions in emissions of the relevant air
pollutant as are required by this part [part D of title I] or may
reasonably be required by the Administrator for the purpose of ensuring
attainment of the applicable national ambient air quality standard by
the applicable date'' as required by section 172(c)(2) of the Act.
2. Quantitative Milestones
Our guidance provides for a quantitative milestone for the year
2000. Addendum at 42016. Based on the statutory requirement for
milestones every three years, the years 2003 and 2006 are the next two
milestones for areas with an attainment date extension under section
188(e). The MAG plan provides milestones for 2003 and 2006 but
substitutes 2001 for 2000. We believe this minor deviation from our
guidance is appropriate and acceptable for the following reasons.
First, we set the milestone schedule in our serious PM-10 area
guidance assuming the area involved was one of the initial moderate
areas and its moderate area plan demonstrates attainment by December
31, 1994. General Preamble at 13539 and Addendum at 42016. Although the
Phoenix area was one of the initial moderate nonattainment areas, its
moderate area plan did not demonstrate attainment.\33\ As a result, our
guidance on the appropriate milestone years is not strictly applicable
to the MAG serious area plan.
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\33\ The moderate area plan submitted by the State in 1991 and
revised in 1993 and 1994 demonstrated the impracticability of
attainment by December 31, 1994. While we have subsequently
disapproved this impracticability demonstration because the plan did
not include RACM, we confirmed that attainment was impracticable in
our 1998 FIP. 63 FR 41340.
---------------------------------------------------------------------------
We also believe that the statutory purpose for including milestones
in PM-10 plans is best served in the Phoenix area by having the
milestone year be 2001 rather than 2000. Under the Act, states are to
submit a demonstration 90 days after a milestone date that the state
has implemented all measures in its approved plan and has met the
milestone. See CAA section 189(c)(2). If a state fails to submit a
report or we determine that the area has not met a milestone, then the
state must submit a plan revision that assures that the next milestone
will be met. See CAA section 189(c)(3).
It is clear from the statutory requirements, that the milestone
requirement functions as a mid-course evaluation of the PM-10 plan and
an opportunity to make corrections to the plan to assure that there is
no delay in attainment due to failures to implement or achieve needed
reductions. As such, the milestones should be keyed, to the extent
possible, to major implementation deadlines in a manner that allows for
a realistic and comprehensive look at the effectiveness of the
implemented measures.
The BACM implementation deadline for Phoenix is June 10, 2000. A
December 31, 2000 milestone allows for the evaluation of only a half-
year of implementation, which is little time to see if implementation
is going to achieve the expected emission reductions. Setting the
milestone one year later on December 31, 2001 as the MAG plan does,
provides for a full year of implementation allowing for a more
realistic assessment of the effectiveness of BACM yet still leaving
ample time to make any corrections needed to assure timely attainment.
Therefore, we believe that strict adherence to the 2000 milestone date
in our guidance would be less beneficial to attainment in the Phoenix
area than setting the date at 2001.
The next milestone in the MAG plan after the 2001 one is in 2003.
MAG plan, Figure 8-4. This second milestone is only 2 years after the
first, instead of 3 years arguably required by the Act. However, we
believe that the 3-year milestone increment in CAA section 189(c) is
the maximum allowable time between milestones and nothing in the
section prohibits states from setting milestones dates that are closer
together.
The assumptions regarding control measures' implementation and
effectiveness that underlie the quantitative milestones are reasonable
and consistent with the RFP demonstration.
For these reasons, we propose to find that the MAG plan meets the
quantitative milestone requirement in CAA section 189(c)(1).
I. General SIP Requirements
Section 110(a)(2)(E)(i) of the Clean Air Act requires that
implementation plan provide necessary assurances that the State (or the
general purpose local government) will have adequate personnel, funding
and authority under State law. Requirements for legal authority are
further defined in 40 CFR part 51, subpart L (section 51.230-232) and
for resources in 40 CFR 51.280.
States and responsible local agencies must demonstrate that they
have the legal authority to adopt and enforce provisions of the SIP and
to obtain information necessary to determine
[[Page 19989]]
compliance. SIPs must also describe the resources that are available or
will be available to the State and local agencies to carry out the
plan, both at the time of submittal and during the 5-year period
following submittal.
We propose to find that the implementing agencies for the MAG plan
have adequate resources for implementing their respective commitments.
We also propose to find that the MAG plan adequately describes the
resources that are available or will be available to the State and
local agencies to carry out the Plan, both now and over the next 5
years. See discussion of the individual commitments and control
measures in the TSD.
All agencies and jurisdictions appear to have adequate authority
under Arizona state law to implement their respected commitments and,
where applicable, to obtain information necessary to determine
compliance. We, therefore, propose to find that these agencies/
jurisdictions have demonstrated that they have adequate legal authority
to implement the MAG plan.
Section 110(a)(2)(C) requires SIPs to include a program to provide
for the enforcement of SIP measures. The implementing regulation for
this section is found at 40 CFR 51.111(a) and requires control
strategies to include a description of enforcement methods including
(1) procedures for monitoring compliance with each of the selected
control measures, (2) procedures for handling violations, and (3) the
designation of the agency responsible for enforcement.
The principle control measures in the plan are MCESD's Rules 310
and 310.01. Procedures for monitoring compliance (i.e., the inspection
strategy) with these rules are described in Maricopa County's
commitments. See Maricopa County commitment, 1999 Revised Measure 6.
Based on the review of MCESD's enforcement procedures, we propose
to find that the MAG plan adequately provides for the enforcement of
the principle measures relied on for attainment and that the plan
includes an adequate description of enforcement methods as required by
our regulations.
Section 110(a)(2)(E)(iii) requires SIPs to include necessary
assurances that where a State has relied on a local or regional
government, agency or instrumentality for the implementation of any
plan provision, the State has responsibility for ensuring adequate
implementation of the such plan provision.
We have previously found that Arizona law includes the necessary
assurances that where a State has relied on a local or regional
government, agency or instrumentality for the implementation of any
plan provision, the State has responsibility for ensuring adequate
implementation of the such plan provision. 60 FR 18010, 18019 (April
10, 1995).
Proposed Actions on Maricopa County Rules
A. Rule 310
Rule 310 establishes requirements for fugitive dust sources on
facilities that have or are required to have air quality permits from
MCESD. These facilities include construction sites, stationary sources,
and any other facility or operation that is required to have a permit
under MCESD rules. The rule requires earthmoving activities that
disturb 0.10 acre or more to apply for and get approval of a Dust
Control Plan (DCP) and requires other permitted sources to obtain a DCP
prior to commencing any routine dust generating activity. We have
described many of the Rule's specific requirements earlier in this
preamble.
The current SIP approved version of Rule 310 is the version adopted
on September 9, 1994. We approved this version of Rule 310 into the SIP
on August 4, 1997 as part of the Microscale plan. 62 FR 41856
MCESD adopted a revised version of Rule 310 and Appendix C to MCESD
rules on February 16, 2000 and Arizona submitted both as a revision to
the Arizona SIP on March 2, 2000. Appendix C contains the test methods
relied on in Rule 310.
The revised Rule 310 is considerably different from the current
SIP-approved version. The greatest change has been to split the old
rule into two new rules: the revised Rule 310 that addresses permitted
facilities and a new Rule 310.01 that addresses nonpermitted sources.
We evaluate Rule 310.01 in the next section. MCESD also revised Rule
310 to strengthen it compared to the current SIP-approved version.
These rule improvements include:
MCESD has also committed to continue to strengthen and improve Rule
310 through research on test methods, dust control methods, and revised
recordkeeping requirements. See discussion in section F.3.g.,
``Construction Sites and Activities.''
We believe that the revised Rule 310 is a considerable improvement
over the SIP-approved version and, combined with MCESD commitments to
continue to improve the Rule and to improve enforcement and compliance
with it, provides for implementation of RACM and BACM and the inclusion
of the MSM on the sources subject to it. We, therefore, propose to
approve Rule 310 and Appendix C as adopted on February 16, 2000 and
submitted on March 2, 2000, into the Arizona SIP.
We have described in more detail the improvements and other
revisions to Rule 310 in section 6 of our TSD.
B. Rule 310.01
Rule 310.01 establishes requirements for fugitive dust emitted from
nonpermitted sources, including unpaved public roads, unpaved parking
lots, open areas and vacant lots, erosion-caused deposits of bulk
materials onto paved surfaces, and commercial feedlots and/or
commercial livestock areas.
The provision of Rule 310.01 are currently in the SIP as sections
of former Rule 310. We approved this version of Rule 310 into the SIP
on August 4, 1997 as part of the microscale plan. 62 FR 41856.
MCESD adopted Rule 310.01 on February 16, 2000 and Arizona
submitted it as a revision to the Arizona SIP on March 2, 2000. As with
Rule 310, Rule 310.01 relies on the test methods in Appendix C.
Rule 310.01's provisions are strengthened compared to the similar
provisions in the SIP. These rule improvements and other rule changes
include:
[[Page 19990]]
We believe that Rule 310.01 is a considerable improvement over the
SIP-approved version and, combined with MCESD's commitments to continue
to improve the Rule and enforcement and compliance with it and the
commitments by the County and local jurisdictions to address unpaved
roads, unpaved parking lots, and vacant lots, provides for
implementation of RACM and BACM and the inclusion of the MSM on the
sources subject to it. We, therefore, propose to approve Rule 310.01 as
adopted on February 16, 2000 and submitted on March 2, 2000, into the
Arizona SIP.
We have described in more detail the strengthenings and other
revisions to Rule 310.01 in section 6 of our TSD.
C. Residential Woodburning Restriction Ordinance
Combined with MCESD Rule 318 ``Approval of Residential Woodburning
Devices'' (adopted April 21, 1999; approved November 8, 1999 (64 FR
60678)), Maricopa County's Residential Woodburning Restriction
Ordinance implements a mandatory woodburning curtailment program. The
curtailment program restricts the types of woodburning devices that can
be used during periods of high PM-10 concentrations. The ordinance
allows the Control Officer to declare restricted-burn periods when the
particulate matter pollution levels could exceed the ``particulate
matter no-burn standard.''
The SIP-approved ordinance provides that restricted-burn periods
are declared by the Control Officer when the Control Officer determines
that air pollution levels could exceed the 24-hour PM standard at 150
Because approving this revision will strengthen the SIP and when
combined with the MAG plan's other provision for residential
woodburning will provide for the implementation of BACM and the
inclusion of the MSM, we are proposing to approve it into the SIP. See
section F.3.j. ``Residential Wood Combustion.''
D. CAA Section 110(l) Finding
CAA section 110(l) prohibits us from approving a revision to the
applicable implementation plan if that revision would interfere with
any applicable requirement concerning attainment and reasonable further
progress (RFP) or any other applicable requirement of the Act. We
interpret section 110(l) to mean that we cannot approve a plan revision
if that revision would mean that the plan would no longer provide for
attainment or RFP as these are required by the CAA for that plan or if
the revision would mean that the plan would no longer meet another
requirement of the Act that applies to the plan. For a further
discussion of this interpretation, see 61 FR 51599, 51608 (October 3,
1996).
We are proposing to revise the Arizona SIP to incorporate the
revised Rule 310, Rule 310.01 and the Maricopa County Residential
Woodburning Ordinance in replacement of the previous version of Rule
310 approved in August, 1997 and of the ordinance approved in November,
1999. In addition to the effect on attainment and RFP, the ``other
applicable requirement of the Act'' that we must be concerned with for
this proposal is the Act's requirements for implementation of RACM and
BACM and the inclusion of the MSM.
We are proposing to approve the expeditious attainment and RFP
demonstrations in the MAG plan. These demonstrations are in part
dependent on approval of the revised Rule 310, Rule 310.01, and the
woodburning ordinance.
We are also proposing to find that the MAG plan provides for the
implementation of RACM and BACM and the inclusion of the MSM for
construction sites, unpaved roads, unpaved parking lots, and disturbed
vacant lands. Again, these findings are in large part dependent on
approval of the revised Rule 310 and Rule 310.01. We, therefore,
propose to find that approval of the revised Rule 310 and Rule 310.01
will not interfere with plan's compliance with the Clean Air Act's
requirements for attainment, RFP, implementation of RACM and BACM, and
inclusion of the MSM as they apply to construction sites, unpaved
roads, unpaved parking lots, and disturbed vacant lands.
Finally, we are proposing to find that the MAG plan provides for
the implementation of BACM and for the inclusion of MSM for residential
woodburning. These proposed findings are made in part based on the
revised ordinance. Therefore, we propose to find that our approving the
ordinance will not interfere with the plan's compliance with the Act's
requirements for the implementation of BACM and the inclusion of MSM as
they apply to residential woodburning.
We have previously found that the Arizona SIP provided for the
implementation of RACM for residential woodburning. 64 FR 60678
(November 8, 1999). The State has now strengthened its residential
woodburning program, in part with the revised ordinance; therefore, we
propose that approval of the revised ordinance will not interfere with
the Arizona SIP's compliance with the requirement for the
implementation of RACM as it applies to residential woodburning.
Administrative Requirements
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
proposed action is not a ``significant regulatory action'' and
therefore is not subject to review by the Office of Management and
Budget. This proposed action merely approves state law as meeting
federal requirements and imposes no additional requirements beyond
those imposed by state law. Accordingly, the Administrator certifies
that this proposed rule will not have a significant economic impact on
a substantial number of small entities under the Regulatory Flexibility
Act (5 U.S.C. 601 et seq.).
Because this rule proposes to approve pre-existing requirements
under state law and does not impose any additional enforceable duty
beyond that required by state law, it does not contain any unfunded
mandate or significantly or uniquely affect small governments, as
described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4).
For the same reason, this proposed rule also does not significantly
or uniquely affect the communities of tribal governments, as specified
by
[[Page 19991]]
Executive Order 13084 (63 FR 27655, May 10, 1998). This proposed rule
will not have substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132 (64 FR 43255, August
10, 1999), because it merely approves a state rule implementing a
federal standard, and does not alter the relationship or the
distribution of power and responsibilities established in the Clean Air
Act.
This proposed rule also is not subject to Executive Order 13045 (62
FR 19885, April 23, 1997), because it is not economically significant.
In reviewing SIP submissions, our role is to approve state choices,
provided that they meet the criteria of the Clean Air Act. In this
context, in the absence of a prior existing requirement for the State
to use voluntary consensus standards (VCS), we have no authority to
disapprove a SIP submission for failure to use VCS. It would thus be
inconsistent with applicable law for us, when reviewing a SIP
submission, to use VCS in place of a SIP submission that otherwise
satisfies the provisions of the Clean Air Act. Thus, the requirements
of section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (15 U.S.C. 272) do not apply.
As required by section 3 of Executive Order 12988 (61 FR 4729,
February 7, 1996), in issuing this proposed rule, we have taken the
necessary steps to eliminate drafting errors and ambiguity, minimize
potential litigation, and provide a clear legal standard for affected
conduct.
We have complied with Executive Order 12630 (53 FR 8859, March 15,
1988) by examining the takings implications of the rule in accordance
with the ``Attorney General's Supplemental Guidelines for the
Evaluation of Risk and Avoidance of Unanticipated Takings'' issued
under the executive order.
This proposed rule does not impose an information collection burden
under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C.
3501 et seq.).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Intergovernmental
relations, Particulate matter, Reporting and recordkeeping
requirements.
Authority: 42 U.S.C. 7401 et seq.
Dated: April 3, 2000.
Laura Yoshii,
Acting Regional Administrator, Region IX.
[FR Doc. 00-8833 Filed 4-12-00; 8:45 am]
BILLING CODE 6560-50-U
Table 1-1.--Control Measures Relied on in the Attainment Demonstration
------------------------------------------------------------------------
Emission
Measure Implementation mechanism reduction
(mtpd)
------------------------------------------------------------------------
Strengthening and Better Rule 310 and Maricopa 60.6
Enforcement of Fugitive Dust County Commitments,
Rules (Construction sites). 1999 Revised Measure 6.
Unpaved roads and alleys........ Rules 310 and 310.01, 12.2
Maricopa County
Commitments, 199
Revised Measures 6 &
17, City/Town
Commitments for Unpaved
Roads and Alleys.
Unpaved parking lots............ Rules 310 and 310.01 and 3.7
Maricopa County
Commitments, 1999
Revised Measure.
Vacant disturbed lots........... Rules 310 and 310.01 and 1.8
Maricopa County
Commitments, 1999
Revised Measure 6.
01PM-10 MAG Commitment, ``PM-10 1.1
efficient Efficient Street
street sweepers Sweepers'' City/Town/
(MAG). County Commitments for
Street Sweeping.
Curbing, paving, or stabilizing City/Town/County 1
shoulders on paved roads. Commitments for
Stabilizing Shoulders.
Curbing paving or stabilizing City/Town/County 0.4
unpaved access points. Commitments for
Stabilizing Unpaved
Access Points.
PM-10 episode thresholds........ Maricopa County 0.07
Residential Woodburning
Restriction Ordinance.
Restaurant charbroiler controls Maricopa County 0.07
(Maricopa County commitment). Commitment, 1999
Revised Measure 23.
Cleaner Burning Gasoline........ ADEQ Regulations 0.03
(already SIP approved).
Pre-1988 Heavy-Duty Diesel A.R.S. 49-542 F.7....... 0.02
Vehicle Standards.
Coordinate traffic signals...... City/Town/County 0.01
Commitments for
synchronizing traffic
lights..
------------------------------------------------------------------------