[Federal Register Volume 73, Number 54 (Wednesday, March 19, 2008)]
[Rules and Regulations]
[Pages 14687-14713]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-5188]
=======================================================================
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 52 and 81
[EPA-R09-OAR-2006-0583, FRL-8542-6]
Approval and Promulgation of Implementation Plans; Designation of
Areas for Air Quality Planning Purposes; State of California; PM-10;
Affirmation of Determination of Attainment for the San Joaquin Valley
Nonattainment Area
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: EPA is finalizing its proposal to affirm its October 30, 2006,
determination that the San Joaquin Valley nonattainment area (SJV or
the Valley) in California has attained the National Ambient Air Quality
Standard (NAAQS) for particulate matter with an aerodynamic diameter
less than or equal to a nominal 10 micrometers (PM-10). EPA proposed to
affirm the determination of attainment in order to take comment on the
exclusion from a
[[Page 14688]]
determination of attainment of PM-10 exceedances that were caused by
exceptional events. EPA is concurring with the State's request to flag
exceedances which occurred in the SJV as being caused by exceptional
events, i.e., high winds. EPA is also concurring with the Santa Rosa
Rancheria Tribe's request to flag, as due to an exceptional event, PM-
10 exceedances which occurred on tribal lands located within the
boundaries of the SJV. EPA is further finding that these exceedances at
the Santa Rosa Rancheria (SRR) should be excluded from use in
determining attainment because the exceedances occurred while the
monitor was operating in very close proximity to construction
activities and, as such, the monitor was not properly sited during that
time for purposes of comparison to the NAAQS. As a result, EPA is
affirming its determination that the SJV has attained the PM-10
standard based on EPA's evaluation of quality-assured data through
2006.
In addition, EPA did not receive comments on how the Agency
addressed the issues raised in petitions for reconsideration and
withdrawal of EPA's 2006 determination of attainment, filed by
Earthjustice on behalf of the Sierra Club, Latino Issues Forum and
others, and thus we are denying the petitions.
DATES: Effective Date: This rule is effective on April 18, 2008.
ADDRESSES: EPA has established docket number EPA-R09-OAR-2006-0583 for
this action. The index to the docket is available electronically at
www.regulations.gov and in hard copy at EPA Region IX, 75 Hawthorne
Street, San Francisco, California. While all documents in the docket
are listed in the index, some information may be publicly available
only at the hard copy location (e.g., copyrighted material), and some
may not be publicly available in either location (e.g., CBI). To
inspect the hard copy materials, please schedule an appointment during
normal business hours with the contact listed in the FOR FURTHER
INFORMATION CONTACT section.
FOR FURTHER INFORMATION CONTACT: Doris Lo, EPA Region IX, (415) 972-
3959, [email protected] or Bob Pallarino, EPA Region IX, (415) 947-4128,
[email protected].
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us'' and
``our'' refer to EPA.
Table of Contents
I. Summary of Proposed Action
II. Public Comments and EPA Responses
A. Earthjustice Comments
1. Overview Comments
2. Comments Specific to September 22, 2006--Corcoran,
Bakersfield and Oildale
3. Comments Specific to October 25, 2006--Corcoran and
Bakersfield
B. Other Comments
C. List of EPA Figures in the Docket
III. Final Action
IV. Statutory and Executive Order Reviews
I. Summary of Proposed Action
On August 27, 2007, EPA proposed to affirm its determination that
the SJV has attained the 24-hour NAAQS for PM-10. 72 FR 49046.\1\ EPA
issued this proposed rule in order to take comment on the exclusion of
several PM-10 exceedances that were caused by exceptional events, and,
in the case of the SRR, improper siting of the monitor for purposes of
comparison to the NAAQS. These exceedances are summarized in Table 1 in
the proposed rule. Id. at 49047. For a more detailed discussion of the
related background for the SJV and of the proposal, please refer to the
proposed rule.
---------------------------------------------------------------------------
\1\ On October 17, 2006, EPA finalized its determination that
the SJV attained the NAAQS for PM-10 and on October 30, 2006, EPA
published this determination in the Federal Register. 71 FR 63642.
---------------------------------------------------------------------------
II. Public Comments and EPA Responses
EPA received three comment letters supporting the proposal to
affirm the attainment determination. These comments were submitted by
the California Cotton Ginners and Growers Association, the Tulare
County Farm Bureau and the Western United Dairymen. In general, these
commenters support the cases that are made for the exceptional event
exceedances and discuss the many control measures and efforts that have
been made to achieve attainment. The commenters also point to the SJV's
continued efforts to achieve further air quality improvements under the
PM-2.5 plan development. One commenter provides information to show
that no cotton harvesting was occurring in September 2006. Finally, the
commenters question the representativeness of the 2000 comment letters
received by EPA in response to our July 19, 2006, attainment
determination proposal (71 FR 40952) since the majority of the
commenters appear to reside outside the SJV.
EPA received three adverse comment letters. Two were from private
citizens from the state of Tennessee and one was from Earthjustice,
representing Sierra Club, Latino Issues Forum, Medical Advocates for
Healthy Air, the Steven and Michele Kirsch Foundation, Tri-Valley
CAREs, Concerned Residents of Lockwood Valley, Fresno Coalition Against
the Misuse of Pesticides, California Communities Against Toxics, Fresno
Metro Ministry, Coalition for Clean Air, Center for Biological
Diversity, and the Association of Irritated Residents.\2\ The majority
of the comments discussed below are raised by Earthjustice.
---------------------------------------------------------------------------
\2\ The proposal provided a 30 day comment period ending on
September 26, 2007. EPA received a request for an additional 30 days
to comment and granted that request extending the comment period
until October 26, 2007. 72 FR 53743 (September 20, 2007).
---------------------------------------------------------------------------
EPA notes that although it received numerous specific comments on
the September 22, 2006, October 25, 2006, and the SRR exceedances, no
adverse comments are directed specifically at EPA's finding that
exceedances monitored on December 8, 2006, at Corcoran and Bakersfield-
Golden State Highway (Bakersfield) were caused by an exceptional high
wind event. Thus, EPA does not address any substantive issues regarding
these exceedances in its responses to comments.
In subsection A. below we respond to the extensive comments raised
by Earthjustice. In subsection B. we respond to comments raised by
other parties.
A. Earthjustice Comments
1. Overview Comments
Comment 1: Earthjustice explains that its comments analyze EPA's
proposed affirmation rule under the new Exceptional Events Rule (EER).
72 FR 13560 (March 22, 2007). In this regard, Earthjustice states that,
``assuming EPA has the discretion to apply the new rule,'' EPA's
decision to do so is completely arbitrary given that the San Joaquin
Valley Air Pollution Control District (District or SJVAPCD) prepared
its analyses under EPA's prior policies and did not invoke the new
regulatory requirements.
Response 1: EPA addressed the issue of the applicability of the new
EER to the events at issue in this rulemaking in its proposed
affirmation rule. EPA explained that the statutory provision upon which
the new rule is based, CAA section 319, as amended by section 6013 of
the Safe Accountable Flexible Efficient-Transportation Equity Act: A
Legacy for Users (SAFE-TEA-LU) of 2005, provides that the Agency's pre-
existing guidance documents continue to apply until the effective date
of the rule. CAA section 319(b)(4). As mandated by section 319, EPA
finalized and published the final EER in March 2007. This rule became
effective on May 21, 2007, requiring EPA to follow the rule in making
exceptional events determinations after that date.
[[Page 14689]]
Therefore, in making and publishing its determination after the
effective date of the EER, EPA followed its procedures and criteria in
evaluating the State's exceptional events demonstrations. 72 FR at
49048.
Although EPA followed the EER in this particular instance, and
believes it should be followed in most cases, the Agency recognized
that there might be certain instances where EPA had not yet made a
decision on a state's already completed and submitted demonstration of
an exceptional event and these demonstrations were thus caught
midstream. In those instances, EPA concluded that a state could choose
for a limited period to comply with either the provisions of the rule
or those of the Agency's existing policies and, that if asked, EPA
would act under the policy on a grandfathering rationale for a short
time period. EPA continues to believe that this transitional policy was
reasonable in the absence of an explicit statutory directive addressing
that situation. Here, the State did not indicate that its submissions
should be evaluated under the existing policies. Therefore, EPA applied
the rule, which was already effective, when it made its determinations
on the exceptional events in the SJV.
Comment 2: Earthjustice, citing case law, states that EPA must
provide a rational basis to support its conclusions regarding the
exclusion of monitoring data showing NAAQS exceedances and that its
decisions must have a ``substantial basis in facts.'' Earthjustice
cites 40 CFR 50.14(c)(3)(iii) and CAA section 319(b)(3)(B),
respectively, for the propositions that for EPA's determination here
the District must provide actual evidence to support its claims and
that the occurrence of an exceptional event must be ``demonstrated by
reliable, accurate data.'' Earthjustice claims that even under a weight
of evidence standard there must be evidence supporting the specific
findings and that reliance on a plausible story is not enough.
Response 2: EPA agrees with Earthjustice's characterization of the
general demonstration, as stated in our summary of its comment above,
that must be made in order to exclude data showing NAAQS exceedances.
EPA believes that it has, both in the proposed affirmation rule and
this final rule, provided a rational basis supported by reliable,
accurate data for its conclusions that the September, October and
December 2006 PM-10 exceedances in the SJV were caused by exceptional
events. See 72 FR at 59050-49063 and our responses to comments below.
Comment 3: Regarding its contention concerning the lack of reliable
and accurate data, Earthjustice cites EPA's statements in the proposed
affirmation rule at 72 FR at 49053 that activity levels on September
22, 2006 were ``constant'' and that reasonable controls were in place
to control particulate matter while providing only general or anecdotal
evidence in the form of non-specific District inspector observations
and ``discussions with representatives of agricultural and industrial
operations.'' Citing CAA section 319(b)(3)(B), Earthjustice claims that
this does not satisfy the statutory requirement that ``exceptionality''
be based on reliable, accurate data.
Response 3: In the section of the proposed affirmation rule cited
by Earthjustice we discussed our conclusion that the State's
documentation demonstrates that the exceedances at Corcoran,
Bakersfield and Oildale on September 22, 2006 would not have occurred
but for the wind event on this day. EPA based this conclusion on the
totality of the evidence presented by the State which included, but was
not limited to, the information on activity levels and control measures
singled out by Earthjustice. For the additional factors EPA considered
in reaching its conclusion, see section V.A.2.d. in our proposed
affirmation rule (72 FR at 49053) and our responses to comments below.
Comment 4: Earthjustice claims that EPA offers no evidence to
support the construction claims regarding the SRR. It asserts that EPA
cannot say what if anything was occurring on the days in question,
where it was occurring, or why it could not be reasonably controlled.
Earthjustice also maintains that EPA cannot show that construction
activity at the SRR is related to the measured exceedances and, as a
result, EPA cannot show the required ``clear causal relationship.''
Further, EPA cannot say when these events occurred and why these
allegedly ongoing activities only resulted in exceedances during the
same period that monitors in other areas of the SJV started monitoring
exceedances. Earthjustice argues that EPA cannot make the required
``but for'' showing at the SRR because EPA cannot show that there was
an event in the first place. Earthjustice further contends that EPA did
not provide adequate evidence, including written accounts, that the
construction activity took place on the days the exceedances occurred.
Earthjustice claims that ``no one was able to produce any written
account, in the form of contractor records, work orders, schedules, or
anything else that would confirm that construction activity did, in
fact, take place on the days in question.'' Finally, Earthjustice
states that ``mere post hoc speculation and anecdotal accounts of what
probably happened does not establish a basis for waiving these data.''
Response 4: First, Earthjustice notes that EPA proposed to exclude
the SRR violations on two grounds: (1) The monitor was not properly
sited, and (2) the nearby construction activity was an exceptional
event. Earthjustice concedes that ``[b]oth of these conclusions seem
reasonable if the activity can be shown to have occurred on the days
the monitor recorded violations.'' Earthjustice Comments (EC) at 23.\3\
Earthjustice contends, however, that EPA did not provide ``any such
evidence.''
---------------------------------------------------------------------------
\3\ Earthjustice concedes, moreover, that under the EER the
requirements for tribal governments appear to be ``much more
flexible * * * '' and ``[i]t would not take much to make these
demonstrations.'' EC at 22.
---------------------------------------------------------------------------
Contrary to Earthjustice's assertion, EPA in its proposed
affirmation rule provided a demonstration that construction activity,
involving the grading and paving of parking lots, took place in close
proximity to the SRR monitor during the period the exceedances at the
SRR monitor occurred, and that this activity caused the exceedances.
EPA in its proposal set forth information derived from eyewitness
accounts, meteorological data, contemporaneous tracking reports, and an
account of an EPA expert's own visit to the site. 72 FR at 49060-49063.
EPA did include written documentation of the events at issue. This
written documentation included sample tracking reports that accompanied
the filters from the monitors and described the conditions at the time
of the monitoring, and an EPA expert's report of his site visit and
interviews of witnesses to the events. There is no requirement in the
EER that documentation of events include specific types of written
documentation, such as those cited by Earthjustice.\4\ Nor
[[Page 14690]]
is there any requirement for specific types of documentation for EPA to
demonstrate its alternative ground for excluding the data under
principles established in 40 CFR part 58, appendix E, that during the
period of the nearby construction the monitor was not properly sited
for purposes of collecting data for comparison to the NAAQS. 72 FR at
49060-49061.
---------------------------------------------------------------------------
\4\ Note that we are not specifying what will be required as a
minimum level of documentation in all cases because facts and
circumstances will vary significantly based on, among other things,
geography, meteorology and the relative complexity of source
contributions to measured concentrations in any particular location.
72 FR at 13573. A particular instance may require more or less
documentation, depending on the particular facts or circumstances.
The simplest demonstrations could consist of newspaper accounts or
satellite images to demonstrate that an event occurred together with
daily and seasonal average ambient concentrations to demonstrate an
unusually high ambient concentration level, which is clearly
indicative of an exceptional impact. Such is the case with events
such as volcanic eruptions and nearby forest fires. Id. More
documentation would be needed to support situations that are not as
straightforward.
---------------------------------------------------------------------------
EPA's findings were supported by information from interviews with
three individuals with firsthand knowledge of the activities that took
place near the monitor, as well as by contemporaneous documentation
from filter sample tracking reports. These individuals were the SRR
environmental technician responsible for overseeing the operation of
the monitor, the SRR construction superintendent, and a private
environmental consultant working for the Santa Rosa Rancheria EPA
(SRREPA). The construction superintendent and the consultant concurred
with the SRR environmental technician's recollection that grading and
paving of the parking lots took place in September and October 2006,
and the environmental technician concluded that these activities caused
the exceedances on September 14 and 20, 2006 and later in October, when
the initial paving had to be removed and the parking lot repaved.
EPA's July 18, 2007, Memorandum, ``On-Site Visit to Santa Rosa
Rancheria,'' from Bob Pallarino, EPA, to Sean Hogan, EPA (Site Visit
Memorandum), contains the following account:
The construction activity entailed grading and leveling the
ground, application of sub-base material, and paving with asphalt.
The par[k]ing lot was first paved in September and it is this
project which [the SRR environmental technician] believed caused the
exceedances on September 14 and 20. * * * the first paving * * * had
to be removed and the parking lot repaved.\5\ It is this second part
of the paving project which [the environmental technician] believed
caused the October exceedance. * * * [T]he SRR environmental
consultant stated that he had witnessed these construction
activities during September and October, 2006. * * * The
construction supervisor concurred with [the environmental
technician's] recollection of the construction activity * * *.
---------------------------------------------------------------------------
\5\ The Site Memorandum stated that the first paving project
``did not pass inspection and the paving had to be removed and the
parking lot repaved.'' The Facility Manager in his letter of
December 2007 referred to the first paving of the parking lot as
``temporary.''
Site Visit Memorandum at 2-3.
The information about the timing of the construction activity, from
witnesses with both firsthand and expert knowledge, is confirmed by
documentation from the California Air Resources Board (CARB) sample
tracking reports that the SRREPA environmental technician filled out at
the time the samples were obtained, and forwarded to CARB along with
the monitored samples. The SRREPA technician observed the ``sampling
conditions'' at the time the monitor was operating and noted on the
sample tracking forms, which are completed with each sampling run, that
there was ``construction nearby.'' This was signified by the letter
``J''. Earthjustice ignores this corroborating documentation, cited by
EPA in its proposal, and included in the rulemaking docket. 72 FR at
49062. It is significant that these sample tracking forms were prepared
before the filters from the monitors were sent to and analyzed by the
lab. Thus at the time the technician noted that nearby construction was
occurring during the monitoring, he could not have known whether or not
an exceedance was recorded that day.
EPA's proposal also showed that the meteorological data lend
support to the environmental technician's account of the events of the
days in question. The winds on the three days that exceeded the NAAQS
were predominantly from the northwest, north and northeast. This would
indicate that any dust-producing activity north and northeast of the
monitor would result in high concentrations of geologic dust being
blown towards the monitor. Site Visit Memorandum at 2.
Further corroboration of the impact of the construction on the
monitor came from EPA's assessment of the proximity of the monitoring
site to the nearby parking lots. EPA's onsite inspection ascertained
that one of the parking lots was within 25 feet of the monitor, and the
other was within 100 feet. 72 FR at 49062.
Reinforcing EPA's conclusion that construction activities near the
monitor caused the exceedances was the fact, pointed to in the proposed
rule, that after completion of the paving projects, average PM-10
concentrations dropped by more than 50 percent. Id.
Since the proposal, EPA has obtained further documentation that the
exceedances occurred during the period of construction activity in
close proximity to the monitor. The Facility Director of the Tribe's
hotel and casino has provided EPA with a letter stating that asphalt
work on the parking lots close to the monitoring station was completed
between August 15 and November 4, 2006. Enclosed with the letter was a
billing statement from the Tribe's general contractor for the period up
to August 15, 2006. The statement shows that work on the parking lots
close to the monitor remained to be completed after August 15. The
letter from the Facility Director states that at the time of the
monitored exceedances, there were earthmoving activities nearby and
paving activities near the site of the monitor ``in a large area for
parking for Tribal Administrators and for our customers.''
Thus, in addition to the documentation available at the time of the
proposal, EPA has provided a letter from the Tribe and a billing
statement from the general contractor that support the conclusion that
paving work was occurring at the time of the exceedances.
Earthjustice argues that because exceedances did not occur on other
days when construction activities were occurring, this indicates that
construction did not cause the exceedances in September and October
2006. But this argument is misleading. Generally, varying degrees,
types and locations of the construction activity, and changing
meteorological conditions lead to varying impacts on the monitor. The
fact that construction activities did not cause exceedances on some
days does not mean that they were not responsible for the exceedances
that occurred on other days. In addition, although Earthjustice claims
that two days of violations at the SRR ``correlate well with violations
seen in other parts of the Valley,'' no other violations were monitored
in the Valley on September 14 and 20 and October 26, 2006.
Earthjustice also claims that EPA ``still needs to make the other
required showings'' for exceptional events, ``including that these
sources were reasonably controlled.'' EC at 22. EPA made these showings
in its proposal, and Earthjustice did not raise any specific grounds to
challenge them. See 72 FR at 49061-49062. In its proposal EPA, after
discussing whether the construction activity's impact on the monitor
was reasonably controllable, concluded that ``under the particular set
of circumstances presented here, for the purposes of evaluating the
`reasonably controllable' criterion of the EER, we deem this criterion
to have been satisfied.'' EPA found that even if control measures had
been employed, we cannot be certain they would have prevented
exceedances at the monitor, and that EPA's monitor siting rules provide
that the monitor should not be operated at such a time and place for
the purposes for determining attainment. 72 FR at 49062. We note that
the criteria under the EER do not apply for the
[[Page 14691]]
purposes of our alternative ground, that the monitor was not properly
sited. See 72 FR at 49060-49061. Thus EPA is finalizing its
determination that there are two independent bases for determining that
the exceedances recorded at the SRR in September and October, 2006
should be excluded from consideration in determining whether the SJV
has attained the PM-10 standard: (1) The monitor was not properly
sited, under the principles established in part 58, appendix E, and (2)
the construction activity constitutes an exceptional event under EPA's
EER.
Comment 5: Earthjustice states that EPA cannot point to any
statutory or regulatory authority that allows it to treat wind-
entrained particulate matter pollution from land that has been
disturbed by human activities, i.e., agriculture or construction as
``natural.'' Earthjustice observes that, while EPA cites preamble
language in the EER regarding high winds, this language was never
codified even though the final rule does contain provisions relating to
the treatment of other anthropogenic sources such as fireworks and
prescribed fire. Earthjustice suggests that even though a natural event
is defined in 40 CFR 50.1(k) as ``an event in which human activity
plays little or no direct causal role,'' EPA attempts to define an
event in which wind-entrained dust from agricultural and industrial
operations as natural. Earthjustice cites legislative history of the
1990 Clean Air Act Amendments (CAAA) to support its contention that
this result defies logic and flies in the face of Congressional intent
as evidenced by Congress's refusal to excuse dust storms from Mono and
Owens lakebeds because they were human-caused. Earthjustice claims that
if the measures in place are not enough to prevent exceedances due to
wind-entrained dust, then Congress intended that additional controls be
required.
Response 5: Section 319, as amended, defines an exceptional event
as an event that affects air quality, is not reasonably preventable or
controllable, is a natural event or is an event caused by human
activity that is unlikely to recur at a particular location. Under this
definition, for an event to qualify as an exceptional event, both
natural events and events caused by human activity must be events that
are not reasonably preventable or controllable. Therefore,
Earthjustice's conclusion that designating an event ``natural'' would
``allow air agencies to avoid controls'' is erroneous. An agency
flagging data as due to an exceptional event, including a high wind
event, will be required to show that the event was not reasonably
preventable or controllable. In the preamble to the final rule, EPA
explained how it would evaluate whether an agency had been able to
successfully demonstrate that an event met this criteria by taking into
account the controls in place, the wind speed, and other factors. 72 FR
at 13565-13566, 13576-13577. As explained elsewhere in our responses to
comments below, in this particular instance the District's Regulation
VIII (general fugitive dust rules) and Rule 4550 which limits fugitive
dust emissions specifically from agricultural operations through
Conservation Management Practices (CMPs) were in place. In addition,
the District has adopted and is implementing EPA-approved best
available control measures (BACM) for all significant sources of PM-10
in the SJV.
Earthjustice incorrectly states that if an event is classified as a
natural event, a state would be able to ``avoid controls.'' In the
proposed EER, EPA explained that it was proposing to treat high wind
events that result in exceedances or violations as a natural event
provided a clear causal relationship between the wind event and the
measured exceedance was established and contributing anthropogenic
activities were ``reasonably well-controlled.'' \6\ In the final rule,
after considering the comments on high wind events including on the
terminology and the definition, EPA adopted an approach that considers
high winds a natural event if contributing anthropogenic activities are
controlled through ``reasonable and appropriate measures.'' 72 FR at
13566. To qualify as a natural event (a subset of exceptional events
under the rule) a state must demonstrate, among others, that dust from
contributing anthropogenic sources was ``reasonably well-controlled at
the time the event occurred.'' 72 FR at 13576. The EER, therefore, has
already defined what constitutes a high wind event through appropriate
notice and comment rulemaking. Thus, the question of whether a high
wind that causes exceedances or violations due to entrainment of dust
from anthropogenic sources can be defined as a natural event is not an
issue that is open for comment in this rulemaking. In this case, the
Agency has only asked for comments on whether the particular high wind
event met the criteria and procedures established under the rule, e.g.,
establishing a causal connection, reasonable controls on anthropogenic
sources, wind speed and direction, etc., and not on whether these
criteria are appropriate.
---------------------------------------------------------------------------
\6\ EPA made this statement in the context of PM-2.5 because at
the time, the Agency was considering adopting the PM10-2.5 standard
and noted that states would be expected to have appropriate controls
for contributing anthropogenic emissions under the definition of the
proposed PM10-2.5 indicator. The Agency, eventually, did not
finalize the PM10-2.5 indicator and instead retained the 24-hour PM-
10 standard.
---------------------------------------------------------------------------
Earthjustice cites to the legislative history of the 1990 CAAA, for
the discussion on Owens and Mono lakebeds where Congress indicated that
diversion of water from these lakes created an anthropogenic source of
dust. From this Earthjustice contrives an overly-broad conclusion that
any ``dust from lands disturbed by human activity'' must be treated as
an anthropogenic rather than a natural event. Under this proposition
gale-force winds, for example of 100 mph, in an urban area could not be
treated as a natural event because human activity would be a
contributing factor.
As a matter of record, the legislative history also demonstrates
that EPA concurred with Congress that the diversion of water created an
anthropogenic source of dust in the Owens and Mono lakebeds. Pub. L.
101-549, CAA Amendments of 1990 House Report No. 101-290(l), May 17,
1990. EPA, however, does not interpret the statutory language in a
manner that considers any anthropogenic contribution to a natural event
as transforming it into an anthropogenic event. In the Mono and Owens
lakebed situation, EPA believed that the anthropogenic contribution was
such that dust blown from those areas should be treated as
anthropogenic rather than natural events. In other high winds
instances, however, where there were anthropogenic contributions with
adequate controls in place, EPA treated the high wind events as natural
events.
In its Natural Events Policy, EPA stated that it would treat a high
wind event as a natural event even if the dust originated from
anthropogenic sources, provided best available control measures were in
place. Memorandum from Mary D. Nichols, Assistant Administrator for Air
and Radiation to Regional Air Directors, ``Areas Affected by PM-10
Natural Events,'' May 30, 1996 (NEP) at 7. Congress was cognizant of
EPA's existing policies on natural and anthropogenic events and how EPA
interpreted and implemented these policies. In amending section 319,
Congress specifically required EPA to continue to apply its NEP during
the exceptional events rulemaking process, an unlikely action if it
disagreed with EPA's interpretation of natural events. Section 319
(b)(4)(B). Under the NEP,
[[Page 14692]]
EPA treated high wind events as natural events and reasonably well-
controlled if contributing anthropogenic sources had BACM in place. NEP
at 7. During the exceptional events rulemaking, EPA sought comment on a
number of options for mitigation requirements, including whether to
continue to require BACM for such events. After considering all
comments on the proposed options, EPA explained in the preamble to the
final rule that it would continue to require that anthropogenic sources
contributing to high wind events be well-controlled through reasonable
and appropriate measures. 72 FR at 13566. EPA, therefore, believes its
interpretation of a high wind event as set forth in the preamble to the
EER conforms to congressional intent and the requirements of section
319.
Also, in response to Earthjustice's assertion that EPA cites no
statutory or regulatory authority that permits us to treat high wind as
a natural event, as discussed above, Congress was aware of EPA's
interpretation of natural events as evidenced by the statutory
reference to the NEP (Section 319(b)(4)(B)) and it is self-evident that
volcanic, seismic, high wind, and other similar events are natural
events under section 50.1(k) of the EER. Therefore, EPA did not find it
necessary to specifically list these events as exceptional events in
the final rule. When asking for comments in the proposed rule, we noted
that some of these exceptional events (including volcanic, seismic and
high wind events) have ``unusual characteristics'' and needed a fuller
discussion in the preamble regarding how states may meet the
requirements established in the EER. 71 FR at 12605. EPA believed that
this explanation in the preamble was sufficient to assist states in
developing their demonstration requirements and did not make it
necessary to specifically list these events as exceptional events in
the final rule.
Comment 6: Earthjustice claims that even if EPA had codified the
preamble language allowing dust from lands disturbed by human activity
to be excused, EPA offers no evidence to show whether the sources that
allegedly were responsible for the dust were reasonably well controlled
at the time the event occurred. Earthjustice states that EPA must show
that the sources were actually controlled, not just that they were
subject to controls. Earthjustice believes that reasonable controls
would have prevented dust from being entrained by the stated wind
speeds and that if the winds at issue picked up the large amounts of
particulate concentrations claimed, then by definition, these sources
were not reasonably controlled. With respect to September 22, 2006,
Earthjustice asserts that the fact that the District claims that the
dust came from anthropogenic sources being scoured by winds under 25
mph for a short period of time means that reasonable measures could not
have been in place. Therefore, Earthjustice claims that either the dust
was not caused by wind or the sources did not have reasonable controls
that would have prevented the event. With respect to October 25, 2006,
Earthjustice asserts that none of the 90 inspections conducted by the
District was in or around the Lemoore/Corcoran area where the dust
allegedly originated.
Response 6: With respect to reasonable controls, in the preamble to
the EER we explained that ``ambient particulate matter concentrations
due to dust being raised by unusually high winds will be treated as due
to uncontrollable natural events where * * * the dust originated from
anthropogenic sources within the State, that are determined to have
been reasonably well-controlled at the time that the event occurred, or
from anthropogenic sources outside the State.* * * In cases where
anthropogenic sources are determined to have contributed to exceedances
or violations due to high wind events at air quality monitoring sites,
per our decision in this rulemaking concerning the action that States
must take to mitigate the impact of exceptional events on public health
* * * States must take reasonable and appropriate measures to mitigate
the impact associated with the event on public health.'' 72 FR at
13576-13577.
As we observed in our proposed affirmation rule, Regulation VIII
and District Rule 4550 were in place at the time of the events in
question. Furthermore, we noted that EPA has approved the District's
BACM demonstration for all significant sources of PM-10 in the SJV as
meeting CAA section 189(b)(1)(B). See 72 at 49053 and 49057. Moreover,
the District conducted numerous inspections of PM-10 sources in the SJV
on September 22 and October 25, 2006. Thus controls beyond those deemed
``reasonable'' were being implemented and enforced in the SJV on those
dates.
Contrary to Earthjustice's apparent belief, there is nothing in
either the preamble to the EER or the rule itself that requires EPA to
show that all sources were ``actually controlled'' at the time of the
events. Moreover, there are thousands of fugitive dust sources in the
SJV,\7\ an area of nearly 25,000 square miles which constitutes
approximately 16 percent of the geographic area of California. 2003
PM10 Plan for the SJV at 2-1. As a result it would be a practical
impossibility for the District, a publicly-funded agency, to determine
whether every source was in compliance with its regulations on any
given day, the standard Earthjustice evidently espouses. The fact that
the District conducted 90 inspections on October 25, 2006 and none was
in Lemoore or Corcoran simply illustrates the magnitude of the task
Earthjustice suggests should be mandatory for the exclusion of data
from an exceptional event.
---------------------------------------------------------------------------
\7\ For example, the District has approved over 6,000
applications under Rule 4550. ``Conservation Management Practices
Program Report for 2005,'' January 19, 2006, SJVAPCD at 5.
---------------------------------------------------------------------------
Finally, Earthjustice presents no support for its contention that
controls on anthropogenic sources beyond those already in place would
have prevented dust from being entrained by the stated wind speeds.
Earthjustice simply asserts (see comment 7) without evidence that there
are numerous measures available that could have prevented or reduced
entrainment of particulate matter. As we have shown, reasonable
controls were in place on the days in question and the exceedances
occurred notwithstanding those controls. See also our response to
comment 7 below.
Comment 7: Earthjustice further asserts that there are numerous
measures available that could have reduced or prevented the entrainment
of particulate matter by winds above the entrainment threshold of 18
mph, many of which are included but not required by the District's
agricultural CMP rule and Regulation VIII. Earthjustice provides a
number of examples that it claims are effective in reducing or
eliminating erosion and transport of soil particles during high wind
events. Earthjustice concludes that even assuming 100 percent
compliance with the agricultural CMP rule and Regulation VIII, ``not
one of these measures is required to be in place by these so-called
BACM level controls.'' Thus Earthjustice alleges that sources could be
100 percent in compliance with District rules and still not be doing
anything to prevent wind-generated entrainment of particulates.
Response 7: As we stated in the preamble to the EER, where wind
speed results in particulate matter exceedances, a clear causal
relationship must be demonstrated between the exceedances measured at
the air quality monitoring site and the high wind event
[[Page 14693]]
in question in order for data affected by these events to be excluded
under the weight of evidence approach. 72 FR at 13566, footnote 11. We
further stated that ``EPA will consider in the weight of evidence
analysis winds that produce emissions contributed to by anthropogenic
activities that have been controlled to the extent possible through use
of all reasonably available reasonable and appropriate measures.'' Id.
EPA approved Regulation VIII as BACM on February 17, 2006 (71 FR
8461) and Rule 4550 as BACM on February 14, 2006 (71 FR 7683). The
control measures in these rules are designed to reduce fugitive dust
emissions. A number of the measures that sources can choose in
compliance with the rules are also specifically designed to reduce or
prevent entrainment of particulate matter during wind events. See, for
example, in the ``List of Conservation Management Practices,'' May 20,
2004, for Rule 4550 in the ``Cropland--Other'' category the following
measures: alternate till, bulk materials control, cover crops,
permanent crops, surface roughening, wind barrier.
EPA determines what controls constitute ``all reasonably available
reasonable and appropriate measures'' on a case by case basis. With
regard to the SJV, EPA has agreed with the District's finding that ``*
* * unlike other arid western PM-10 serious nonattainment areas, the
SJV does not have a regular and repeated windblown dust problem.'' 71
FR at 7686. In addition, in responding to a comment on its proposed
approval of the 2003 PM-10 serious area plan for the SJV, EPA observed
that ``[o]nly five PM-10 exceedance days spanning a 13-year period were
identified as associated with strong winds.'' 69 FR 30006, 30033 (May
26, 2004). Under these circumstances, EPA believes that it was not
necessary for the District's rules to mandate the selection of
windblown dust measures and that the BACM controls being implemented in
the SJV constitute ``all reasonably available reasonable and
appropriate measures.''
Comment 8: Earthjustice argues that the events at issue cannot be
claimed as exceptional because the District did not make its
demonstration according to the procedures outlined in the EER.
Specifically, Earthjustice states that while EPA relies on
demonstrations prepared by the District in April and May 2007, the only
opportunity for public comment provided by the District was on the
February 2007 version of the analysis. Moreover, Earthjustice states,
only 15 calendar days were provided for comment on the February version
and the preamble to EPA's EER provides for a 30-day comment period.
Earthjustice states that to the extent that EPA believes preamble
statements to be enforceable, the event cannot be deemed exceptional
because the District did not meet the procedural requirements in the
EER. Earthjustice also asserts that since the District's rationale for
flagging the September 22, 2006 exceedances changed so markedly as to
make comments on the first draft irrelevant, the documentation should
have been put out for a second round of public comment. Earthjustice
further states that insofar as the EER applies to EPA's affirmation
action, the District also failed to meet its procedural requirements
that documentation justifying exclusion must be submitted no later than
12 months before a regulatory decision is made. Here, Earthjustice
asserts, EPA based its regulatory decision to find the SJV in
attainment on the exclusion of data before any demonstration supporting
the exclusion was drafted by the State.
Response 8: The public did have an adequate opportunity for review
and comment on the State's documentation of the exceptional events.
Earthjustice complains that the State did not provide a 30-day comment
period on the documentation of exceptional events, and further contends
that there was no opportunity to review and comment after the District
revised this documentation. EPA's EER provides that a state that has
flagged data as being due to an exceptional event and that is
requesting exclusion of the data shall ``after notice and opportunity
for public comment, submit a demonstration'' to EPA, along with any
public comments it received. 40 CFR 50.14(c)(3)(i).
With respect to Earthjustice's first contention regarding the 30-
day comment period, the EER contains no such requirement. The language
cited by Earthjustice that purports to characterize 30 days as a
requirement is found in the preamble only, 72 FR 13574, and does not
reflect the language of the rule. Thus, while indicative of a period
that EPA would deem reasonable, the preamble language regarding a 30-
day comment period does not serve to make such a period mandatory. Nor
does it mean that a shorter comment period should be deemed
unreasonable. Earthjustice concedes that in February 2007 the District
provided a two week comment period for its initial documentation of the
September, October and December 2006 exceedances. The District received
no comments or requests for extension of the comment period.\8\ On
March 21, 2007, Earthjustice filed with EPA a petition to withdraw
EPA's October 2006 attainment determination, which cited to and
discussed the District's initial documentation. This petition, however,
was directed to EPA and not to the District or the State. Earthjustice,
having failed to request an extension of the comment period and to
address comments to the District and the State, cannot now be heard to
complain about the length of the initial comment period.
---------------------------------------------------------------------------
\8\ Contrary to Earthjustice's contention (EC at 3, footnote 3),
EPA in its proposal did nothing to ``hide'' the date that the
documentation became available. EPA simply stated that the
documentation became available in February.
---------------------------------------------------------------------------
Subsequently, the District posted on the ``Public Notices'' section
of its Web site revised versions of the documentation for exceedances
on these three days at issue, and thus the revised documentation was
also available for public review and comment. These revised versions
modified and clarified the technical analysis of the high wind events.
For the September 22 event, the District posted on its Web site a
revised set of documentation, dated April 20, and CARB subsequently
submitted it to EPA. The District submitted an Addendum to CARB on May
23, 2007, which it again posted on its Web site, and CARB later
submitted it to EPA. 72 FR at 49050. For the October 25 event, the
District posted on its Web site a revised set of documentation, dated
April 23, and CARB again subsequently submitted it to EPA. 72 FR at
49054. For the December 8, 2006 event, which Earthjustice does not
contest is an exceptional event, the District revised its documentation
and submitted it to CARB on May 23, 2007, and posted it on its Web
site. At CARB's request the District made further revisions which it
submitted to CARB on June 6, 2007, and posted on its Web site. 72 FR at
49057. The State later submitted it to EPA. Id.
Thus each set of revised documentation was available to the public
in the ``Public Notices'' section of the District's Web site for months
prior to EPA's August 15, 2007 issuance of its proposed rule, and EPA
has found no indication that comments were submitted or inquiries
received about the revised documentation. EPA therefore believes that
there was adequate opportunity for the public to comment on the revised
demonstrations made by the District and CARB. The fact remains that no
comments were submitted to the District or CARB on the original
versions of the documentation, nor does it appear that there were any
requests for an extension of the comment period that closed on March 5,
[[Page 14694]]
2007. Similarly, EPA knows of no comments or requests regarding the
comment period that were submitted on the subsequent versions of the
documentation that were posted on the District's Web site.
Earthjustice further contends that EPA has failed to meet the
requirement that a demonstration be submitted to EPA no later than 12
months ``prior to the date'' a regulatory decision ``must'' be made by
EPA. EER, section 50.14(c)(3)(i). We note initially that this section
of the EER is designed for EPA's benefit, to furnish adequate time to
review documentation, and it is thus for EPA to determine whether we
require the full time allotted by the rule.
Furthermore, in the preamble we ``recognize that special
circumstances could dictate more expedited data delivery, flagging, and
minimal demonstrations * * *.'' 72 FR at 13571. In this case, where EPA
is acting to affirm a prior attainment determination that recognized
the need for additional evaluation of preliminary data, EPA finds there
is value in proceeding expeditiously to obtain and review the State's
documentation of those data and surrounding exceptional events.
Moreover, this action to affirm EPA's attainment determination is not a
regulatory decision that ``must'' be made by a certain date, and
therefore the 12-month requirement is not applicable. Finally we note
that the bulk of the revised documentation for the September and
October 2006 exceedances at issue here was submitted to EPA in April
and May 2007, well in advance of EPA's final regulatory decision in
this rulemaking. Thus EPA finds that, for all the reasons set forth
above, the timing of submission of the documentation here was adequate
for purposes of section 50.14(c)(3)(i) of the EER.
Earthjustice also complains that in issuing the October 2006
determination of attainment, EPA made the determination to finally
concur in the flagging of exceptional events prior to receiving the
State's documentation. The procedural validity of the October 2006
determination, and whether it provided adequate notice and comment, is
not at issue in today's rulemaking. Thus Earthjustice's contentions
with regard to notice and comment issues arising from the October 2006
rulemaking are misplaced here.
Moreover, Earthjustice's contentions are belied by the facts. EPA's
October 2006 determination of attainment made clear that the data
showing exceedances on September 22, 2006 were preliminary. EPA stated
that once quality-assured data were available, EPA would review those
data and CARB's request with respect to them, evaluate whether the data
qualified for exclusion as caused by exceptional events, and determine
whether the determination should be withdrawn.\9\ See discussion in
EPA's proposed affirmation rule, 72 FR at 49064. See also 71 FR 63642.
---------------------------------------------------------------------------
\9\ As EPA noted in its proposed affirmation rule, EPA's
October, 2006 final determination did not ignore the exceedances
that occurred in October 2006 since these occurred eight days after
EPA promulgated its final determination of attainment. 72 FR at
49064.
---------------------------------------------------------------------------
In today's rulemaking EPA has fulfilled its promise by providing
ample opportunity for comment on the State's documentation and EPA's
evaluation of exceedances under the EER prior to issuing a final
concurrence. As EPA noted in its proposed affirmation rule, our purpose
here is not to take comment on the issues raised by the 2006 attainment
determination, except to the extent that they affect EPA's ability to
determine that the SJV continued to attain the PM-10 standard through
2006. 72 FR at 49047. The October 2006 rulemaking, which is not at
issue in this current action, did not purport to be a final concurrence
on the State's exceptional events documentation for the September 22,
exceedances. Today's rulemaking addresses quality-assured data for
September, October and December 2006, for which the State has provided
exceptional events documentation.
Comment 9: Earthjustice states that EPA argues that at the time of
the attainment finding the Agency merely deferred its determination of
the impact of the preliminary data until they could be quality assured
and the State had an opportunity to show that the exceedance was caused
by an exceptional event. Earthjustice claims that the data at issue had
in fact been processed by the CARB laboratory and thus already quality
assured by the State when EPA was notified of the September 22, 2006
exceedances. In this respect, Earthjustice believes that EPA
mischaracterized CARB's October 17, 2006 letter to EPA to mean that the
data from the filter analyses were preliminary. Thus, Earthjustice
concludes that EPA's decision not to consider the September 22
exceedances in its October 17, 2006 attainment finding is a violation
of law and an abuse of discretion. Earthjustice also states that this
violation of the Administrative Procedure Act (APA) cannot be cured
with this rulemaking's post-hoc rationalization. Earthjustice
interprets 40 CFR 51.14(c)(2)(ii) to mean that an exceedance must be
considered an exceedance unless and until EPA gives final concurrence
following a thorough, convincing, publicly reviewed demonstration that
the data can be ignored.
Response 9: As noted in the response to comment 8 above, the
adequacy and validity of the October 2006 rulemaking is not at issue in
this proceeding. Whether the APA was violated in that rulemaking is not
at issue here. In this current rulemaking, EPA thoroughly reviewed and
proposed to concur with the documentation submitted by the State, and
provided full opportunity for public review and comment before
finalizing its concurrence with the flags, and before excluding the
data from a final determination of attainment. The purpose of this
rulemaking is to assess the quality-assured data and documentation of
exceptional events claims in the context of notice and comment
rulemaking. Thus, even if, for the sake of argument, we accept
Earthjustice's contentions that there were procedural deficiencies in
the October 2006 rulemaking, EPA would have cured any such deficiencies
with the procedures it has followed in this rulemaking.
In any event, Earthjustice is incorrect in its assertions that, at
the time of the October 2006 rulemaking, data for September 22, 2006
were not preliminary and had been quality assured. The data for the
September 22 exceedances were plainly preliminary. An EPA staff
employee e-mailed a CARB branch chief an informal request to ``find out
if there was any preliminary data available from the ARB lab.'' E-mail
from Bob Pallarino, EPA, to Karen Magliano, Chief, Air Quality Data
Branch, Planning and Technical Support Division, CARB, October 12,
2006. On October 13, 2006 she forwarded to EPA an informal e-mail
originating from a CARB staffer. The e-mail included data from filter
analyses of several monitors, which set forth numerical values
representing monitored data. That e-mail stated clearly: ``Of course,
all the data is preliminary.'' E-mail from Scott Randall, Inorganic
Laboratory Section, Northern Laboratory Branch, CARB, to Cliff Popejoy,
Inorganic Laboratory Section, Northern Laboratory Branch, CARB, October
13, 2006 (forwarded to Bob Pallarino by Karen Magliano). Thus, CARB
represented and EPA reasonably believed that the data showing monitored
exceedances were ``preliminary'' and not quality assured. Indeed, EPA
believed that the normal data validation and verification processes had
not been undertaken, and that, in fact, the data had not been
[[Page 14695]]
submitted to EPA's Air Quality System (AQS) database \10\ or certified
by CARB. The message that the CARB staffer sent was in response to an
informal request from EPA staff, and in that context EPA did not
consider it an official CARB submission of data. The informal and
preliminary nature of the information is further indicated by the fact
that the numerical values for PM-10 reported in the e-mail were not
accompanied by scientific units, which would be essential documentation
in any official submission of quality-assured data, and could only be
inferred by EPA based on usual practice.
---------------------------------------------------------------------------
\10\ Data from air monitors operated by state and local agencies
in compliance with EPA monitoring requirements must be submitted to
AQS. Heads of monitoring agencies annually certify that these data
are accurate to the best of their knowledge. See 71 FR at 40953.
---------------------------------------------------------------------------
EPA did not therefore, as Earthjustice contends,
``mischaracterize'' the data from the filter analyses, when it
described the data as ``preliminary.'' EC at 11, footnote 9. CARB
itself characterized the data as preliminary when it forwarded them to
EPA.
In any event, as noted above, what is at issue in this rulemaking
is EPA's concurrence on the exceptional events documentation for
quality-assured data subsequent to EPA's October 2006 determination,
and not the procedural validity of that prior determination. It is
clear in this rulemaking that EPA is determining to finally concur on
the State's flagging of the data only after EPA has conducted notice
and comment rulemaking on documentation that the State has submitted to
support those flags.
Comment 10: For the wind events, Earthjustice maintains that the
data offered by the District and relied upon by EPA does not
demonstrate a ``clear causal relationship'' because exceedances were
being measured before the events occurred.
Response 10: EPA disagrees with Earthjustice's conclusion for the
reasons discussed below. Initially it is important to understand that
the 24-hour PM-10 NAAQS, 150 [mu]g/m\3\, is a 24-hour average
concentration. This means that individual hourly concentrations at any
given monitoring location may exceed 150 [mu]g/m\3\, but until all 24
hours of a day are sampled a complete daily reading cannot be
calculated. Therefore it is incorrect to characterize the data, as
Earthjustice does, as showing that NAAQS exceedances were measured
before the wind events.
To support its contention, Earthjustice states that fugitive dust
sources in the Lemoore area on September 22 and October 25, 2006 could
not have caused the Corcoran NAAQS exceedances since the first hourly
PM-10 concentrations exceeding 150 [mu]g/m\3\ at Corcoran occurred
either an hour before or at the same time as the Lemoore meteorological
station recorded wind speeds exceeding the District's threshold wind
speed. From these facts, Earthjustice concludes that since the monitor
was already recording an hourly concentration above the NAAQS before
the dust-laden winds from Lemoore \11\ arrived on September 22 and
October 25, the monitor could not have been impacted by them.
---------------------------------------------------------------------------
\11\ Throughout this final rule when we refer to Lemoore,
Corcoran and Bakersfield, we mean the Lemoore area, the Corcoran
area, and the Bakersfield area. When analyzing data, the State,
District and EPA use information collected from specific points
where the monitors are located, whether meteorological monitors or
PM-10 monitors. Since it is not possible, due to finite resources,
to monitor pollutant or meteorological parameters in every location,
monitoring locations are chosen to be representative of larger
areas. The size of the area represented by a monitor is dependent on
a number of factors, including, but not limited to, the parameter
being measured (e.g., wind speed, PM-10 concentration), the overall
terrain (e.g., urban, rural, valley, etc.) and any localized
characteristics that may influence the parameter being measured
(e.g., obstructions such as buildings or trees).
---------------------------------------------------------------------------
In evaluating this conclusion it is instructive to look at any
number of days where the level of an hourly PM-10 concentration at
Corcoran exceeded the level of the 24-hour NAAQS, yet the 24-hour
average concentration for the day did not exceed the NAAQS. October 26
and 27, 2006, March 26 and 27, 2007, April 17, 2007, May 2 and 21,
2007, and June 5, 2007, all experienced one or more hours exceeding the
level of the NAAQS yet the NAAQS for the day was not exceeded. See
Table 1 below. The most extreme example is April 17, 2007, on which
four continuous hourly concentrations greater than 150 [mu]g/m\3\ were
recorded from 4:00 p.m. Pacific Standard Time (PST) through 7 p.m. PST
(181, 466, 460, 236 [mu]g/m\3\, respectively), yet the overall 24-hour
average concentration for that day was only 91 [mu]g/m\3\.
Table 1.--Non-Exceedance Days With One or More Hourly Pm-10 Concentrations Above 150 [mu]g/m\3\ as Measured at Corcoran
--------------------------------------------------------------------------------------------------------------------------------------------------------
Oct 26 Oct 27 Mar 26 Mar 27 Apr 17 May 2 May 21 Jun 5
2006 2006 2007 2007 2007 2007 2007 2007
Hour* ([mu]g/ ([mu]g/ ([mu]g/ ([mu]g/ ([mu]g/ ([mu]g/ ([mu]g/ ([mu]g/
m\3\) m\3\) m\3\) m\3\) m\3\) m\3\) m\3\) m\3\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0............................................................... 157 79 8 0 27 18 17 21
1............................................................... 143 135 11 0 26 14 16 15
2............................................................... 146 126 8 1 30 13 15 12
3............................................................... 147 89 11 3 31 11 13 13
4............................................................... 161 69 9 3 29 12 15 24
5............................................................... 175 91 10 3 63 26 16 24
6............................................................... 194 221 22 5 73 23 25 22
7............................................................... 232 184 19 7 34 25 28 19
8............................................................... 115 158 16 0 34 20 35 14
9............................................................... 66 149 12 8 33 13 42 18
10.............................................................. 53 107 2 1 22 16 59 23
11.............................................................. 92 117 6 18 21 16 66 35
12.............................................................. 128 86 8 122 15 20 72 61
13.............................................................. 128 70 17 162 26 22 74 87
14.............................................................. 133 91 7 152 54 25 85 77
15.............................................................. 115 69 7 190 138 28 84 254
16.............................................................. 126 87 18 54 181 151 94 169
17.............................................................. 152 116 19 86 466 239 195 145
18.............................................................. 151 140 128 47 460 61 180 173
19.............................................................. 145 116 407 8 236 27 127 235
20.............................................................. 161 126 48 17 136 13 108 65
[[Page 14696]]
21.............................................................. 147 118 16 15 34 14 66 34
22.............................................................. 124 141 4 9 14 29 61 27
23.............................................................. 130 105 0 10 7 16 66 49
---------------------------------------------------------------------------------------
Daily Average................................................... 137 116 34 38 91 36 65 67
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: EPA Air Quality System Database.
* Hours are in PST. All State and local ambient air pollutant monitoring equipment in California operates on PST all year and is never adjusted for
Daylight Savings Time. For example, hour 12 in the table is 1 p.m. Pacific Daylight Time (PDT).
Thus, as can be seen from Table 1 and the discussion above,
Earthjustice is incorrect when it concludes that dust-laden winds from
Lemoore could not have affected the Corcoran monitor on September 22
and October 25, 2006 because concentrations above the level of the
NAAQS were recorded at the monitor before the winds arrived. By failing
to account for all 24 hours of the day, Earthjustice has misinterpreted
how EPA determines compliance with the 24-hour PM-10 NAAQS.
Earthjustice further states that fugitive dust sources in the
Lemoore area on September 22 and October 25, 2006 could not have caused
the Corcoran NAAQS exceedances since the first hourly PM-10
concentrations exceeding the level of the NAAQS at Corcoran occurred
either an hour before or at the same time as the Lemoore meteorological
station recorded wind speeds exceeding the 18 mph threshold speed.\12\
Earthjustice notes that on September 22 the 6:00 a.m. hourly PM-10
concentration at Corcoran exceeded the level of the NAAQS and wind
speeds recorded in Lemoore did not exceed the threshold wind speed
until 7 a.m. On October 25 the Corcoran hourly PM-10 concentration
first exceeded the level of the NAAQS at 6 a.m., the same time the
Lemoore meteorological station recorded winds in excess of the
threshold speed.\13\ However, as set forth below, the data show that on
September 22 the winds at Lemoore began exceeding the threshold speed
at 6 a.m. PST, and likely began affecting the concentrations at the
Corcoran monitor by the time concentrations were recorded at 7 a.m.
PST.\14\ On October 25, the winds recorded at Lemoore exceeded the
threshold speed at 5 a.m. PST and likely affected the concentrations
recorded at the Corcoran monitor beginning at 6 a.m. PST. Thus on both
days there was at most a period of one or two hours where the
concentrations at the monitor that exceeded the standard might not have
been attributable to the winds from Lemoore.
---------------------------------------------------------------------------
\12\ The State cites a 2002 California Regional PM-10/PM-2.5 Air
Quality Study (2002 CRPAQS Study) that established a dust-generating
wind speed threshold of 17.8 mph to support its conclusion that
these wind speeds were sufficient to erode soils and entrain dust
into the atmosphere as well as to exacerbate the entrainment of dust
from the anthropogenic activities. See our proposal at 72 FR at
49052.
\13\ As will be discussed further below, EPA uncovered an error
in the reporting of the meteorological data from Lemoore. The data
for Lemoore winds were reported in the State's documentation in PDT
as opposed to the other meteorological and PM-10 concentration data
which were reported in PST. This means that the wind speeds
increased an hour earlier than had previously been reported in the
State's documentation. Therefore when Earthjustice refers to wind
data from Lemoore at 6 a.m. and 7 a.m., the actual times were 5 a.m.
and 6 a.m. PST.
\14\ Hourly concentrations recorded by PM-10 continuous monitors
are reported in the beginning hour. That is, an hourly average
concentration calculated from readings taken between the hours of 7
a.m. and 8 a.m. would be reported as the average hourly
concentration for 7 a.m.
---------------------------------------------------------------------------
Nevertheless, based upon meteorological data, EPA believes that the
high concentrations measured beginning at 7 a.m. PST on September 22
and 6 a.m. on October 25 and continuing throughout the day were due to
transport of dust by high winds in the Lemoore area, and thus resulted
in the exceedance of the 24-hour NAAQS. In reaching this conclusion,
EPA evaluated the available hourly concentration data from the Corcoran
monitoring site \15\ from October 1, 2006 through June 30, 2007 to
determine how often the Corcoran site recorded high hourly
concentrations in the morning. While high morning concentrations were
relatively rare in the data we evaluated, when they do occur they do
not always result in a 24-hour average concentration that exceeds the
NAAQS. Table 2 below compares days with high morning concentrations,
October 26 and 27, 2006, that did not exceed the 24-hour NAAQS with
September 22 and October 25, 2006, days with high morning
concentrations that ultimately did exceed the 24-hour NAAQS.
---------------------------------------------------------------------------
\15\ In October 2006, the SJVAPCD began the routine submittal of
continuous PM-10 data to EPA's AQS database. These data are recorded
with a special purpose Federal Equivalent Method (FEM) monitor and
the District began submitting these data in response to new
requirements contained in EPA's revised monitoring regulations (71
FR 61236, October 17, 2006). Prior to this regulation revision, air
monitoring agencies were not required to submit special purpose
monitoring data to the AQS database. Therefore, the amount of
certified pollutant data available for our analysis is limited to
October 1, 2006 through September 30, 2007.
Table 2.--Corcoran Hourly Concentrations on September 22, October 25, October 26 and October 27, 2006
----------------------------------------------------------------------------------------------------------------
September 22, October 25, October 26, October 27,
Hour (standard time) 2006 (conc. 2006 (conc. 2006 (conc. 2006 (conc.
[mu]g/m\3\) [mu]g/m\3\) [mu]g/m\3\) [mu]g/m\3\)
----------------------------------------------------------------------------------------------------------------
0............................................... 63 84 157 79
1............................................... 39 57 143 135
2............................................... 51 38 146 126
3............................................... 64 42 147 89
4............................................... 55 30 161 69
5............................................... 78 39 175 91
[[Page 14697]]
6............................................... 170 269 194 221
7............................................... 306 346 232 184
8............................................... 519 651 115 158
9............................................... 531 674 66 149
10.............................................. 725 777 53 107
11.............................................. 695 794 92 117
12.............................................. 521 681 128 86
13.............................................. 318 580 128 70
14.............................................. 276 510 133 91
15.............................................. 247 302 115 69
16.............................................. 269 179 126 87
17.............................................. 283 184 152 116
18.............................................. 258 180 151 140
19.............................................. 223 178 145 116
20.............................................. 150 166 161 126
21.............................................. 144 201 147 118
22.............................................. 138 183 124 141
23.............................................. 144 150 130 105
---------------------------------------------------------------
Daily average............................... 261 304 137 116
----------------------------------------------------------------------------------------------------------------
Source: EPA Air Quality System Database, ``Natural Event Documentation, Corcoran, Oildale and Bakersfield,
California, September 22, 2006'' San Joaquin Valley Unified Air Pollution Control District, April 20, 2007 and
``Natural Event Documentation, Corcoran and Bakersfield, California, October 25, 2006,'' San Joaquin Valley
Unified Air Pollution Control District, April 23, 2007.
As can be seen from Table 2, early morning hourly concentrations on
October 26 and 27, 2006 were comparable to morning hourly values on
September 22 and October 25, 2006. All of these days recorded high
early morning hourly values. However, the hourly concentrations on
September 22 and October 25, 2006 continue to increase throughout the
morning and into the afternoon and evening while the hourly
concentrations for October 26 and 27 begin to decrease after hour 7 and
then later increase slightly in the afternoon and evening. As discussed
above, we believe the increasing concentrations for the morning and
afternoon for September 22 and October 25 are associated with an
increase in hourly wind speeds, as measured in Lemoore. Even if we
assume that several of the hours of high early morning concentrations
at Corcoran on September 22 and October 25 were caused by something
other than windblown dust, we have shown that there would not have been
an exceedance of the 24-hour NAAQS that day without the subsequent high
hourly concentrations that were caused by windblown dust transported
from the Lemoore area.
Moreover, an evaluation of meteorology in the Lemoore area on
October 26 and 27, 2007 shows that the wind conditions on September 22
and October 25, 2006 were much different from October 26 and 27, days
that had high morning concentrations but ultimately did not exceed the
24-hour NAAQS. Table 3 below summarizes this information.
Table 3.--Corcoran Hourly PM-10 Concentrations and Lemoore Hourly Wind Speeds for September 22, October 25, October 26 and October 27, 2006
--------------------------------------------------------------------------------------------------------------------------------------------------------
September 22, 2006 October 25, 2006 October 26, 2006 October 27, 2006
---------------------------------------------------------------------------------------
Hour Conc. Lemoore Conc. Lemoore Conc. Lemoore Conc. Lemoore
([mu]g/ windspeed ([mu]g/ windspeed ([mu]g/ windspeed ([mu]g/ windspeed
m\3\) (mph) m\3\) (mph) m\3\) (mph) m\3\) (mph)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0............................................................... 63 12 84 10 157 3 79 7
1............................................................... 39 9 57 10 143 0 135 6
2............................................................... 51 10 38 10 146 7 126 7
3............................................................... 64 8 42 17 147 7 89 6
4............................................................... 55 10 30 16 161 8 69 6
5............................................................... 78 8 39 22 175 9 91 7
6............................................................... 170 21 269 22 194 3 221 6
7............................................................... 306 21 346 22 232 0 184 3
8............................................................... 519 28 651 26 115 0 158 0
9............................................................... 531 29 674 29 66 0 149 3
10.............................................................. 725 23 777 31 53 5 107 6
11.............................................................. 695 17 794 30 92 3 117 5
12.............................................................. 521 17 681 28 128 0 86 3
13.............................................................. 318 21 580 26 128 0 70 5
14.............................................................. 276 14 510 22 133 0 91 6
15.............................................................. 247 5 302 20 115 0 69 7
16.............................................................. 269 10 179 14 126 5 87 7
[[Page 14698]]
17.............................................................. 283 9 184 3 152 3 116 5
18.............................................................. 258 6 180 6 151 5 140 6
19.............................................................. 223 8 178 8 145 7 116 .........
20.............................................................. 150 7 166 9 161 6 126 8
21.............................................................. 144 9 201 8 147 8 118 0
22.............................................................. 138 0 183 8 124 8 141 3
23.............................................................. 144 7 150 ......... 130 6 105 8
---------------------------------------------------------------------------------------
Daily Average............................................... 261 ......... 304 ......... 137 ......... 116 .........
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: EPA AQS Database, Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowest/.
From this tabulation we can see that while hourly concentrations
measured at Corcoran exceeded the level of the NAAQS during the morning
hours on all four days, it was only on September 22 and October 25,
2006 that sustained high winds in the central SJV, represented by data
from the Lemoore area, generated enough fugitive dust to cause an
increase in the hourly concentrations in Corcoran recorded at and after
7 a.m. PST on September 22 and at and after 6 a.m. PST on October 25.
These increases in hourly concentrations throughout the morning hours
were a result of the high winds that occurred in the Lemoore area.
Therefore it is incorrect to conclude, as Earthjustice does, that the
State cannot show a causal connection between the winds and the 24-hour
PM-10 exceedances at Corcoran on September 22, 2006 simply because the
monitor recorded an hourly concentration above the level of the NAAQS
at the same time winds in the Lemoore area began to exceed the
threshold wind speed. Further, contrary to Earthjustice's contention,
the winds at Lemoore on October 25, 2006 exceeded the threshold for
entrainment prior to the time that increased concentrations were
recorded at Corcoran and likely affected those concentrations.
Finally, the timing of the wind speeds shows an increase an hour
earlier than was previously reported, and thus a corresponding earlier
impact on the monitor. In evaluating the State's documentation we
uncovered an error in how the meteorological data from the Lemoore
meteorological station was reported. In both its April 20, 2007
``Natural Event Documentation, Corcoran, Oildale and Bakersfield,
September 22, 2006,'' and its April 23, 2007 ``Natural Event
Documentation, Corcoran and Bakersfield, October 25, 2006,'' the
District reported the Lemoore meteorological data in PDT as opposed to
PST. This was confirmed when EPA independently obtained data for the
Lemoore meteorological monitoring station. As noted previously in Table
1, all State and local ambient air pollutant monitoring equipment in
California operates on PST year round and is never adjusted for
Daylight Savings Time. Therefore, the information presented in Table 3
of the State's April 20, 2007 documentation and Table 1 of the State's
April 23, 2007 documentation incorrectly lists the time when winds in
Lemoore reached the threshold wind speeds.
As can be seen in Table 3 above and Tables 4 and 5 below, which
reflect the proper times for reported wind speeds, on September 22,
2006 winds at Lemoore reached 21 mph, exceeding the threshold wind
speed, at 6 a.m. PST, which would be 7 a.m. PDT. On October 25, 2006
winds at Lemoore reached 22 mph at 5 a.m. PST, which would be 6 a.m.
PDT. This adjustment strengthens the State's demonstration by showing
that the winds in Lemoore affected the PM-10 concentrations at Corcoran
and Bakersfield an hour earlier than originally reported in the
documentation.
Comment 11: Earthjustice asserts that the one run of the model that
EPA relies on demonstrates that there is no connection between the
events in and around Lemoore and the exceedances measured in
Bakersfield and Oildale.
Response 11: The model to which Earthjustice refers is the Hybrid
Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT).
However, contrary to Earthjustice's assertion, EPA did not rely on the
State's HYSPLIT analysis to make its decision to concur with the
State's demonstration of causal connection. Rather, in its proposal,
EPA noted the limitations of the HYSPLIT model, describing it merely as
offering some support to the State's demonstration that winds were of
the appropriate intensity and direction to move a plume of dust from
the central SJV to the Bakersfield area.\16\ See 72 FR at 49052. EPA is
concurring with the State's causal connection demonstration based on
actual meteorological data recorded on September 22 and October 25,
2006 which show winds of the appropriate intensity and direction
occurring at the appropriate times.
---------------------------------------------------------------------------
\16\ The Oildale monitoring site does not record hourly PM-10
concentrations but uses a manual PM-10 sampler that provides only
24-hour average concentrations. The Bakersfield-Golden State Highway
monitoring site utilizes both a manual sampler for average 24-hour
PM-10 concentrations and a continuous PM-10 analyzer to provide
hourly concentrations. Since the Bakersfield-Golden State Highway
site and the Oildale site are relatively close to each other (3.5
miles apart), we believe it is appropriate to use the Bakersfield-
Golden State Highway continuous analyzer to characterize the
temporal distribution of hourly concentrations at both sites.
---------------------------------------------------------------------------
The State's demonstration included actual meteorological data that
showed that there were wind speeds between Corcoran and Bakersfield
that exceeded the threshold wind velocities. For example, the State's
demonstration for September 22 included meteorological data from a
monitoring station in Alpaugh (15 miles SSE of Corcoran) which showed
winds in excess of the 18 mph threshold at 9:00 am PST and in the 15-16
mph range until 12 pm PST. Wind gusts at Bakersfield Meadow Field
Airport also approached the threshold wind speed, with a gust speed of
17 mph recorded at 12:30 p.m. PST. The hourly concentrations in the
Bakersfield area began to exceed the level of the PM-10 NAAQS at noon
and stayed above 200 [mu]g/m\3\ for the remainder of the day. We
discussed the transport of dust from the Lemoore and Corcoran
[[Page 14699]]
areas in our proposal at 72 FR at 49052 for September 22 and at 49055-
49056 for October 25. As we indicated, the winds between Lemoore and
Corcoran and Corcoran and Bakersfield were sufficient to keep entrained
dust suspended so that it could be transported.
As part of our review of the State's documentation we researched
whether any other publicly available meteorological data supported the
State's demonstration and found that wind data collected at Allensworth
State Park (20 miles SE of Corcoran) also recorded wind speeds on
September 22, 2006 in excess of the 18 mph. While most of the wind
speeds recorded in Alpaugh and Allensworth State Park in the late
morning and afternoon hours did not exceed the threshold wind speed, we
believe these wind speeds were sufficient to transport suspended PM-10
from the Corcoran area to the Bakersfield area. See our proposed rule
at 72 FR at 49052. The wind direction from all of the sites on
September 22 is consistent with the south, southeast transport of dust
(i.e., winds from the north and northwest) from the Lemoore area to
Corcoran and the Bakersfield area as demonstrated by Table 4 below.
Table 4.--September 22, 2006 Daytime Hourly Windspeeds and Concentration Data for the Central and Southern SJV
----------------------------------------------------------------------------------------------------------------
Bakersfield
Hour Lemoore WS/WD/gusts Corcoran conc. Alpaugh WS*/WD Allensworth State conc. ([mu]g/
([mu]g/m\3\) Park WS/WD m\3\)
----------------------------------------------------------------------------------------------------------------
6............... 21/NW............... 170 5.5/W.............. 3/WSW.............. 74
7............... 21/NW............... 306 3.3/WSW............ 6/NNE.............. 104
8............... 28/NNW/35........... 519 9.7/NNW............ 20/NNW............. 78
9............... 29/NNW/37........... 531 19.1/NNW........... 35................. 114
10.............. 23/NW/30............ 725 15.2/NNW........... 15/NW.............. 103
11.............. 17/NNW/24........... 695 15.5/NNW........... 8/NW............... 139
12.............. 17/NNW/25........... 521 16.1/NW............ ND................. 168
13.............. 21/NNW.............. 318 13.6/NW............ 2/3................ 196
14.............. 14/NNE.............. 276 12.1/NW............ 7/NW............... 239
15.............. 5/N................. 247 12.1/NW............ 8/WNW.............. 294
16.............. 10/N................ 269 10.2/NW............ 7/NNW.............. 285
17.............. 9/NNW............... 283 9.7/NNW............ 5/NNW.............. 281
18.............. 6/N................. 258 5.5/NNW............ 1/WSW.............. 270
----------------------------------------------------------------------------------------------------------------
ND--No Data.
Source: ``Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006,'' San
Joaquin Valley Unified Air Pollution Control District, April 20, 2007; ``Addendum, Natural Event
Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006,'' San Joaquin Valley Unified
Air Pollution Control District, May 23, 2007; Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowest/.
* Wind Speed data at Alpaugh adjusted to 10 meter AGL based on conversion formula in the ``Addendum, Natural
Event Documentation, Corcoran, Oildale and Bakersfield, California, September 22, 2006,'' San Joaquin Valley
Unified Air Pollution Control District, May 23, 2007 at 13.
For October 25, the State included all available meteorological
data in its documentation.\17\ These data support the demonstration
that winds between the Corcoran and Bakersfield areas were sufficient
to transport dust on October 25. We believe that the wind speed and
direction data collected at Alpaugh and Bakersfield Meadow airport,
while not exceeding the threshold wind speed, show that the winds in
this portion of the SJV on October 25 were sufficient to transport
suspended PM-10 from the Corcoran area to the Bakersfield area. See our
proposed rule at 72 FR at 49052. The wind direction from all of the
sites during the daytime hours on October 25 is consistent with the
south, southeast transport of dust (i.e., winds from the north and
northwest) from the Lemoore area to Corcoran and the Bakersfield area
as demonstrated by Table 5 below.
---------------------------------------------------------------------------
\17\ See ``Natural Event Documentation, Corcoran and
Bakersfield, California, October 25, 2006,'' April 23, 2007 at 44-
74.
Table 5.--Hourly Daytime Windspeeds and Concentration Data for Central and Southern SJV on October 25, 2006
----------------------------------------------------------------------------------------------------------------
Corcoran conc. Bkrsfld Meadow Bkrsfld conc.
Hour Lemoore WS/WD/gusts ([mu]g/m\3\) Alpaugh WS*/WD Airport WS/WD ([mu]g/m\3\)
----------------------------------------------------------------------------------------------------------------
6............... 22/NNW/30........... 269 3.5/SSW............ 5/ESE.............. 97
7............... 22/NNW/32........... 346 2.9/W.............. 6/E................ 89
8............... 26/NW/36............ 651 5.6/NW............. 0.................. 88
9............... 29/NNW/39........... 674 17.0/NNW........... 10/NW.............. 123
10.............. 31/NW/37............ 777 16.5/NNW........... 9/WNW.............. 148
11.............. 30/NW/40............ 794 16.8/NNW........... 12/W............... 177
12.............. 28/NNW/38........... 681 15.6/NNW........... 12/WNW............. 195
13.............. 26/NNW/35........... 580 14.8/NNW........... 6/ND............... 222
14.............. 22/NNW/31........... 510 13.2/NNW........... 7/ND............... 415
15.............. 20/NW /26........... 302 13.3/NNW........... 7/NW............... 406
16.............. 14/NNW.............. 179 12.7/NNW........... 3/WNW.............. 393
17.............. 3/N................. 184 6.5/NW............. 5/NW............... 416
[[Page 14700]]
18.............. 6/N................. 180 4.4/WNW............ 3/NW............... 403
----------------------------------------------------------------------------------------------------------------
ND--No data available.
Source: ``Natural Event Documentation, Corcoran and Bakersfield, California, October 25, 2006,'' San Joaquin
Valley Unified Air Pollution Control District, April 23, 2007; Mesowest historical meteorological data,
Mesowest, http://www.met.utah.edu/mesowest/.
* Wind Speed data at Alpaugh adjusted to 10 meter above ground level (AGL) based on the conversion formula in
``Natural Event Documentation, Corcoran, Oildale and Bakersfield, California, October 25, 2006,'' San Joaquin
Valley Unified Air Pollution Control District, April 23, 2007 at 25.
In its documentation the State also included the results of a
HYSPLIT model run by the District to identify source regions for the
parcels of air that impacted the Corcoran and Bakersfield monitors on
September 22 and October 25, 2006. The District explicitly stated that
the models were not intended to quantify particulate concentrations but
simply were used to support its view of the origin of the particulate
matter that impacted the monitors at Corcoran and Bakersfield. As
stated in the proposed rule, EPA agrees that this model run supports
the conclusions drawn from the meteorological data presented. See 72 FR
at 49052 and 49056.
In its comment letter on the proposed affirmation rule,
Earthjustice relies on its own computer simulations using the HYSPLIT
model and appears to claim that, based on its own HYSPLIT analyses, the
winds in the Lemoore area could not have carried sufficient quantities
of particulate matter to Bakersfield to cause exceedances of the PM-10
NAAQS. In order to evaluate Earthjustice's HYSPLIT analyses, EPA also
performed computer simulations using the HYSPLIT model. However, we
took a different approach because we believe that Earthjustice's
HYSPLIT analyses do not represent a comprehensive depiction of the dust
event.\18\
---------------------------------------------------------------------------
\18\ EPA does agree in part with the Jan Null declaration (EC,
Exhibit H) in which he states that the data used by the District in
the HYSPLIT model, EDAS (ETA Data Assimilation System) meso-scale
data, is too coarse to account fully for both the complex terrain in
and around the SJV and for the close proximity of the stations being
examined. However, Earthjustice and EPA also used the EDAS meso-
scale data which are of sufficient resolution to account for the
general overall wind flow in the southern SJV and thus provide a
coarse simulation of wind trajectories within the Valley.
---------------------------------------------------------------------------
While Earthjustice used trajectories starting at zero meters in
height and took a two-dimensional approach in assessing the wind event,
we took a more appropriate three-dimensional approach. The EPA approach
recognizes that the dust did not stay at zero meters in height above
ground but instead mixed up higher into the atmosphere where stronger
winds occurred that caused the transport to be faster than
Earthjustice's HYSPLIT analyses indicated. For September 22 and October
25, 2006, for the morning start times, EPA ran trajectories at three
heights: 10 meters, 100 meters and 250 meters. These heights were used
to approximate the transport from near the surface, near the middle and
near the top of the mixed layer \19\ as shown by the HYSPLIT model.
---------------------------------------------------------------------------
\19\ The mixed layer is the unstable layer of the atmosphere in
direct contact with the surface of the Earth. The daytime mixed
layer is characterized by vigorous turbulent mixing. This means that
air or dust laden air at any height within the mixed layer can
impact the surface due to the mixing caused by turbulence.
---------------------------------------------------------------------------
On September 22, 2006, based on the meteorological data and our
HYSPLIT runs, the high winds that began in the Lemoore area around 6
a.m. PST eroded and then transported dust that started to affect the
PM-10 concentrations measured in the Corcoran area by 7 a.m. PST. See
Figure 1, ``Forward Trajectories at 10, 100, & 250 meters, Lemoore Area
to Corcoran, September 22, 2006, 6 a.m. to 8 a.m. PST.''\20\ From
Corcoran and eastward, some of the dust may have been transported more
towards the Sierra foothills. See Figure 2, ``Forward Trajectories at
250 meters, Lemoore to Corcoran and Bakersfield, September 22, 2006, 6
a.m. to 1 p.m. PST.'' West of Corcoran, the dust was transported
southward towards Bakersfield, beginning to affect that area between
the hours of 12 p.m. and 1 p.m. PST. See Figure 2 and Figure 3,
``Forward Trajectories at 10, 100, & 250 meters, Lemoore Area to
Bakersfield, September 22, 2006, 6 a.m. to 1 p.m. PST.'' Based on
hourly PM-10 values, the peak concentration of dust, 725 [mu]g/m\3\,
occurred at about 10 a.m. PST in Corcoran and a PM-10 value of 294
[mu]g/m\3\ occurred at about 3 p.m. PST in Bakersfield. See Table 4
above. See also our response to comment 21 below.
---------------------------------------------------------------------------
\20\ The EPA Figures referenced in this final rule are available
in the docket for this rulemaking action and are listed in section
II.C. below.
---------------------------------------------------------------------------
On October 25, 2006, the scenario was similar to September 22,
2006. EPA's HYSPLIT runs support a finding that the high winds that
began in the Lemoore area around 5 a.m. PST eroded and then transported
dust that started to affect the PM-10 concentrations measured in the
Corcoran area by about 6 a.m. PST. See Figure 4, ``Forward Trajectories
at 10, 100, & 250 meters, Lemoore Area to Corcoran, October 25, 2006, 5
a.m. to 7 a.m. PST.'' From Corcoran and eastward, some of the dust may
have been transported more towards the Sierra foothills. West of
Corcoran, the dust was transported southward towards Bakersfield,
starting to affect that area between 11 a.m. and 12 p.m. PST. See
Figure 5, ``Forward Trajectories at 250 meters, Lemoore to Corcoran and
Bakersfield, October 25, 2006, 5 a.m. to 11 a.m. PST'' and Figure 6,''
Forward Trajectories at 10, 100, & 250 meters, Lemoore Area to
Bakersfield, October 25, 2006, 5 a.m. to 11 a.m. PST.'' The peak
concentration of dust in Corcoran occurred around 11 a.m. PST with a
PM-10 value of 794 [mu]g/m\3\. The peak concentration of dust in
Bakersfield was more obscure with a peak at about 5 p.m. PST and a PM-
10 value of 416 [mu]g/m\3\. See Table 5 above.
EPA believes that our HYSPLIT analyses depict more accurately than
Earthjustice's runs the windblown dust events of September 22 and
October 25 because, in addition to accounting for the various heights
above ground level, we accounted for the wind flows within the Valley
more comprehensively. We recognized that the winds over the eastern
portion of the Valley tended to move towards the east, winds over the
western portion of the valley tended to move more towards the south,
and that there was a transition area in between where winds moved
southeast directly from the Lemoore area to Bakersfield. See Figures 2
and 5 above. Thus we believe that our HYSPLIT analyses were sufficient
to provide a general overview of the direction and speed of dust
[[Page 14701]]
transport in the San Joaquin Valley and support the contention of dust
transport from the Lemoore area to the Corcoran and Bakersfield areas.
Our analyses are also in general agreement with the measured wind data
provided by the State which do account for the complex terrain of the
Valley.
We note again that our concurrence with the State's causal
connection demonstration is based on the meteorological data for
September 22 and October 25, 2006 discussed above. We believe the
HYSPLIT model supports this demonstration by showing that the winds
were of the appropriate intensity and direction to move a plume of dust
from the central SJV to the Bakersfield areas on those days.
Comment 12: Earthjustice claims that the exceedances in the SJV
cannot be deemed to be in excess of normal historical fluctuations
because they occur regularly and at a similar level every fall and are
therefore no different from the exceedances used to designate the SJV
nonattainment in the first place. Thus Earthjustice believes there are
no ``unusual activities'' as EPA states, because the exceedances at
issue here were caused by the same dust-generating activities that
cause exceedances every year.
Response 12: As we discussed in our proposed rule at 72 FR 49052,
for EPA to concur with a state's claim that an exceptional event caused
an exceedance, the state must show that the event is associated with
concentrations that are beyond the normal historical fluctuations. See
40 CFR 50.14(c)(3)(iii)(C).
When the SJV was designated nonattainment for PM-10 in 1991 by
operation of law (56 FR 11101, March 15, 1991), the District had not
implemented the BACM for PM-10 that are currently in place. Since 1991,
the State of California and the SJVAPCD have adopted many rules and
rule amendments that have led to significant reductions in PM-10 and
oxides of nitrogen (NOX) emissions. These rules include, as
discussed above, BACM for fugitive dust sources such as unpaved and
paved roads, vacant lots, construction sites, etc. (Regulation VIII)
and BACM for agricultural sources (Rule 4550--Conservation Management
Practices). See Section 8, ``Natural Event Documentation, Corcoran,
Oildale and Bakersfield, California, September 22, 2006,'' April 20,
2006. These BACM rules for fugitive dust and agricultural sources were
adopted and implemented in mid- to late 2004. See 71 FR 8461 and 71 FR
7683. Given the vast changes in regulatory requirements for PM-10
sources, the dust-generating activities in the early 1990's are not, as
Earthjustice suggests, comparable to those after the full
implementation of BACM in the SJV. Therefore we do not believe that the
September 22 and October 25, 2006 \21\ exceedances are the result of
the same type of dust-generating activities that caused the area to
originally become nonattainment. Nor do we believe that Earthjustice
has substantiated its claim that they are.
---------------------------------------------------------------------------
\21\ With respect to the exceedances at the Santa Rosa
Rancheria, in the proposed rule EPA showed that the concentrations
measured during the construction activity were in excess of normal
historical fluctuations and that after completion of the paving
project average PM-10 concentrations dropped by more than 50
percent. 72 FR at 49062.
---------------------------------------------------------------------------
We originally evaluated whether the September 22 and October 25,
2006 exceedances exceeded normal historical fluctuations in our
proposed rule. See 72 FR at 49053 and 49056. In response to
Earthjustice's comment on the proposed rule that this EER criterion had
not been satisfactorily demonstrated by the State's documentation, EPA
undertook a further analysis of the data collected at the sites that
exceeded the 24-hour PM-10 NAAQS on September 22, 2006 (Corcoran,
Bakersfield-Golden State Highway and Oildale) and October 25, 2006
(Corcoran and Bakersfield-Golden State Highway). EPA included data from
1993 to 2006 in our analysis.\22\ Our statistical analysis shows the
annual percentile values of the data from each of the three sites. In
the preamble to our EER, we state that a comparison of the exceedance
data to the historical 95th percentile values is appropriate for
determining the level of evidence or documentation a state needs to
provide in order for EPA to concur with its flagging request. Extremely
high concentrations relative to the 95th percentile values would
require a lesser amount of documentation to demonstrate that an event
affected air quality. See 72 FR at 13569.
---------------------------------------------------------------------------
\22\ 1993 was chosen as the starting point for data analysis
because that is the year that the SJV was classified as a serious
PM-10 nonattainment area.
---------------------------------------------------------------------------
For Corcoran, when we examine all data collected since 1993,\23\ it
is clear that the 95th percentile values have consistently been below
the level of the 24-hour PM-10 NAAQS and since 1999 the Corcoran site
has not recorded a 95th percentile value greater than 117 [mu]g/m\3\.
The 95th percentile value recorded at Corcoran in 2006 was less than
100 [mu]g/m\3\. Therefore, our analysis of all the data collected at
Corcoran over the past 14 years indicates that the September 22 and
October 25, 2006 exceedances were clearly beyond the normal range of
annual concentrations recorded at this site. See Figure 7, ``Annual
Peak Day PM10 Concentrations at Corcoran.''
---------------------------------------------------------------------------
\23\ From 1993 through 1998, the Corcoran site collected PM-10
data on a once every sixth day schedule using a Federal Reference
Method (FRM) monitor. Beginning in 1999 the Corcoran PM-10 site has
been collecting data on a once every third day schedule using FRM
monitors. In October 2006 the SJVAPCD began operating a continuous
monitor designated as a Federal Equivalent Method (FEM) monitor at
the site to provide everyday PM-10 data to the public. The State and
SJVAPCD report all data from these monitors to the EPA's AQS
database.
---------------------------------------------------------------------------
As with the Corcoran data, we performed a statistical analysis of
the data collected at the Bakersfield-Golden State Highway site using
data from 1993 to 2006 and calculated the annual percentile values.
From this analysis it is clear that the 95th percentile values at
Bakersfield were consistently less than the level of the 24-hour PM-10
NAAQS. In 2006 the 95th percentile value at Bakersfield-Golden State
Highway was 101 [mu]g/m\3\. Therefore our analysis of the Bakersfield-
Golden State Highway data shows that the September 22 and October 25,
2006 exceedances were beyond the normal range of data recorded at this
site during the past 14 years. See Figure 8, ``Annual Peak Day PM10
Concentrations at Bakersfield.''
Finally, our analysis of the data collected at Oildale also shows
that the exceedance recorded at that site on September 22, 2006 was
outside the normal range of historical values. As with the other two
sites discussed above, the 95th percentile values recorded at Oildale
during the past 14 years were consistently below the level of the NAAQS
and the 95th percentile value in 2006 was 111 [mu]g/m\3\. Again, our
analysis of the Oildale data indicates that the September 22, 2006
exceedance recorded at this site was outside the normal historical
fluctuation of data for the past 14 years. See Figure 9, ``Annual Peak
Day PM10 Concentrations at Oildale.''
Therefore, our analysis of all the annual data from 1993 through
2006 shows that the September 22 and October 25, 2006 exceedances are
in excess of normal fluctuations.
To address Earthjustice's specific concern that these exceedances
occur routinely in the fall months, defined by Earthjustice as the
months of September, October and November,\24\ we performed the same
statistical test on the Corcoran data using only those values recorded
during those months. From this test it is clear that the 95th
percentile values for all years since 1998 do not exceed the level of
the 24-hour PM-10 NAAQS. The highest 95th percentile value since 1998
was a 146 [mu]g/m\3\ recorded in 2003. Again, this
[[Page 14702]]
analysis demonstrates that the September 22 and October 25, 2006
exceedances recorded in Corcoran, even when we use seasonally adjusted
data, were in excess of the normal historical fluctuations. See Figure
10, ``Annual Peak Fall Day PM10 Concentrations at Corcoran.''
---------------------------------------------------------------------------
\24\ EC at 15.
---------------------------------------------------------------------------
At the Bakersfield monitor, 95th percentile values for the fall
months have been lower than the level of 24-hour PM-10 NAAQS since
2000, with the highest 95th percentile value recorded in that year at
145 [mu]g/m3. In 2006, the fall months' 95th percentile
value was 100 [mu]g/m3. These values show that the
exceedances measured on September 22 and October 25 were outside the
historical fluctuation of data for the fall months. See Figure 11,
``Annual Peak Fall Day PM10 Concentrations at Bakersfield.''
Finally for Oildale, our analysis of the fall 95th percentile
values shows that since 1996 the 95th percentile values have not
exceeded the level of the NAAQS and 1996 had the highest 95th
percentile value (138 [mu]g/m3), with the exception of the
September 22, 2006 concentration of 162 [mu]g/m3. Even
though the 95th percentile value in the fall of 2006 exceeded the level
of the NAAQS, when we look at the historical fall data for Oildale this
value does stand out as outside the normal range. See Figure 12,
``Annual Peak Fall Day PM10 Concentrations at Oildale.''
Therefore, our analysis of the data from 1993 through 2006 for the
months of September through November shows that the September 22 and
October 25, 2006 exceedances were in excess of normal fluctuations.
Comment 13: Earthjustice argues that EPA cannot make the required
``but for'' showing for the locations other than the SRR because either
the model shows that the winds did not blow toward the monitors or the
monitoring data show that the standard was being exceeded even before
the alleged dust-laden winds arrived.
Response 13: With respect to the September 22, 2006 exceedance, see
our responses to comments 10, 11, 16 and 21. With respect to October
25, 2006 see our responses to comments 10, 11 and 43. We also discussed
the ``but for'' demonstration included in the State's documentation in
detail in our proposed action. See 72 FR 49053, 49056-49057.
Comment 14: Earthjustice also argues that to make its ``but for''
showing EPA asserts that no ``unusual activities'' occurred during the
exceedance period and implies that something ``extra'' must have
happened which would mean that an area would either have violations
every day or never and that EPA would then have to conclude that unless
an area violates every day, any violation must be the product of some
exceptional, nonrecurring event. Earthjustice believes that EPA's
reliance on this type of argument to make the ``but for'' claim is
arbitrary and capricious.''
Response 14: Earthjustice takes out of context EPA's consideration
of the fact that there were no other unusual activities at the time of
the September 22 and October 25, 2006 exceedances to draw some extreme
conclusions, such as that the Agency would have to conclude ``that
unless an area violates every day, any violation must be the product of
some exceptional nonrecurring event.'' In this connection, Earthjustice
misunderstands EPA's application of the weight of evidence approach to
the ``but for'' demonstration. In the preamble to the EER, EPA
explained that it would use a ``weight of evidence-based approach to
demonstrate that there would not have been an exceedance or violation
but for the event.'' 72 FR at 13570-13571. EPA explained that through
analyses it was possible to demonstrate that an exceedance would not
have occurred but for the event; however, this analysis does not
require a precise estimate of the estimated air quality impact from the
event. 72 FR at 13570.
In applying this weight of evidence approach, EPA considered the
totality of circumstances surrounding the events for the exceedance
days. EPA included in its consideration, an evaluation of the coarse
particles, information about geologic dust, values representing excess
geologic contributions, comparison of ``adjusted'' PM-10 values with
typical average concentrations during similar periods, information
about control measures, readings on days before and after the
exceedance days, and whether any unusual or out of the ordinary
activities occurred on such days. See 72 FR at 49053. Monitor readings
on the days before and after the event days indicated no violations.
EPA therefore looked to see if on the specific event days there were
activities that were different or unusual as compared to the days when
there were no exceedances in order to rule those in or out as
contributing to the exceedance. Contrary to Earthjustice's contention
that any time there is a violation EPA would conclude that it is due to
some exceptional nonrecurring event, the lack of unusual activities was
just one of the factors that EPA considered in reaching its
determination based on the weight of evidence analyses. Thus, EPA's
consideration of whether or not there were unusual activities in this
context is neither arbitrary nor capricious as Earthjustice claims.
2. Comments Specific to September 22, 2006--Corcoran, Bakersfield and
Oildale
Comment 15: Earthjustice claims that in order to show that an event
has affected air quality, a demonstration must be made that the event
``caused a specific air pollution concentration'' and that the data to
be waived are directly due to the event. Earthjustice asserts that the
District did not provide evidence that demonstrates how enough
particulate matter pollution could have been generated in and
transported from one remote area of the SJV to multiple monitors in
distant locations within the time period of the event. In this regard,
Earthjustice states that while the District cites a study that
allegedly establishes a threshold at which wind begins to erode PM
(sustained winds of 18 mph or gusts of 22.4 mph), there is no basis for
the claim espoused by both the District and EPA that winds below this
threshold velocity can then transport particulate matter pollution long
distances. To support this assertion Earthjustice cites EPA's recent
rulemaking (71 FR 61144, 61146, October 17, 2006) establishing new PM
standards in which EPA concluded that ``thoracic coarse particles
generally deposit rapidly on the ground or other surfaces and are not
readily transported across urban or broader areas.''
Response 15: Earthjustice states that in order to show that an
event affected air quality the State must quantify the amount of PM-10
initially generated at a source location. In our proposed rule we
stated that this criterion (affecting air quality) is met by
establishing that the event is associated with a measured exceedance in
excess of normal historical fluctuations, including background, and
there is a clear causal connection between the event and the
exceedance. 72 FR at 49051. We also discussed how these criteria were
met. Id. at 49051-49052.
Earthjustice seems to be suggesting that in order to meet the
criterion ``affects air quality'' the State should have used an air
quality model such as AERMOD or CalPuff to show the behavior of
fugitive dust. In other words, Earthjustice is asking for a modeling
demonstration that would show, quantitatively, that a given amount
(either in the form of an emission rate or initial ambient
concentrations at the source regions) can produce a particular
concentration at a receptor point (e.g., monitoring site location).
This type of modeling, at the scale Earthjustice is suggesting, is not
an
[[Page 14703]]
appropriate tool for use in this type of application because it cannot
be performed with any degree of accuracy.
The State included in its documentation the results of a study that
determined the threshold wind speed needed to erode geologic material
and entrain the resulting particles into the atmosphere.\25\
Earthjustice states that there is no basis for the claim that lower
wind speeds could transport dust long distances.
---------------------------------------------------------------------------
\25\ Subtask Memorandum, ``3.3 How Well Do Measurements
Characterize Critical Meteorological Features,'' Dave Bush, T & B
Systems, August 24, 2004.
---------------------------------------------------------------------------
While the State did not provide information from a specific study
to demonstrate wind speeds sufficient to transport PM-10 suspended in
the atmosphere, EPA believes it is reasonable to conclude, as the State
did, that if an 18 mph wind is sufficient to erode and entrain coarse
particles into the atmosphere, a lower wind speed is sufficient to keep
particles already entrained in the atmosphere suspended, and to
subsequently transport them considerable distances. To erode geological
material on the ground and cause it to be suspended in the air, winds
must have enough kinetic energy to overcome the attractive forces
between particles, in addition to gravitational forces. High winds also
tend to cause large particles to collide with each other, making them
break apart and become more likely to be lifted up. For particles that
have already been lifted well above ground level, winds need only have
enough occasional upward component (due to turbulence) to overcome
gravitational settling. Also, winds aloft may have been stronger (and
had more turbulence) than suggested by the ground based measurements.
As presented in Table 3 of the State's documentation, the wind
speeds between Lemoore and Corcoran, measured at Corcoran, reached a
maximum speed of 11 mph between hours 6 and 12. See ``Natural Event
Documentation, Corcoran, Oildale and Bakersfield, California, September
22, 2006,'' San Joaquin Valley Unified Air Pollution Control District,
April 20, 2007. Winds in the region between Corcoran and Bakersfield,
measured at Alpaugh and Allensworth State Park, reached 16 mph and 15
mph, respectively, between hours 10 and 16.\26\ EPA believes that wind
speeds of this intensity were sufficient to transport PM-10 from the
central SJV to the Bakersfield area.
---------------------------------------------------------------------------
\26\ Wind speeds at Allensworth State park reached 20 mph and 35
mph at hours 8 and 9. This indicates that while the area around
Lemoore was identified as the source for the PM-10 on September 22,
2006, additional PM-10 was likely generated by winds in the region
between Corcoran and Bakersfield.
---------------------------------------------------------------------------
Regarding Earthjustice's reference to the PM coarse NAAQS final
rule, EPA was noting the difference in expected transport distances for
PM-2.5 versus PM coarse. Note that we stated that coarse particles
generally deposit rapidly on the ground or other surfaces and are not
readily transported across urban or broader areas. 71 at 61146. When
comparing PM-2.5 and PM coarse in urban settings it is true that PM-2.5
is a more regional pollutant and can spread over great distances. PM
coarse particles in urban areas, under meteorological conditions that
do not involve high winds, generally are considered more of a localized
pollutant problem. The statement cited by Earthjustice was not meant to
imply that under windy conditions PM coarse particles would not be
subject to transport. The exceedances that occurred in both Corcoran
and the Bakersfield area on September 22 and October 25, 2006 were the
result of windblown and transported dust from a predominantly rural
area.
Comment 16: Earthjustice provides a chart that it states
demonstrates the range of sustained wind speeds in key areas of the
central and southern SJV on September 22, 2006 with corresponding
hourly PM-10 concentrations. With respect to this chart, Earthjustice,
citing EPA Raw Data Reports, asserts the following:
* * * there was a period of a few hours where the alleged wind
speed threshold was exceeded at the Lemoore Naval Air Station
monitoring site, which is located northwest of the city of Lemoore.
The maximum sustained wind speeds ranged from 21 to 29 miles per
hour between the hours of 7 a.m. and 11 a.m., and again exceeded the
alleged threshold at 1 p.m. The maximum peak gusts (i.e., momentary
bursts of wind) recorded at the Lemoore NAS ranged from 30-40 miles
per hour between the hours of 9 a.m. and 11 a.m. However, just 10
miles southeast of the Lemoore NAS at the Santa Rosa Rancheria,
sustained winds never got any higher than 14.1 miles per hour * * *.
In Corcoran, sustained winds reached only 9.6 miles per hour, and
Bakersfield experienced nothing stronger than 7.8 mile-per-hour
sustained winds * * *. None of the winds experienced outside of
northwest Lemoore were capable of eroding soils and so none of these
areas could have contributed any wind-entrained dust to the PM-10
concentrations recorded on September 22, 2006.
Response 16: As discussed in our response to comment 10, the
Lemoore wind speeds included in the State's documentation were reported
in PDT and not in PST. The Corcoran and Bakersfield PM-10 hourly
concentration data were reported in PST which means that the winds in
Lemoore began to exceed the threshold wind speed at 6 a.m. PST. The
times for the wind speed data in the Earthjustice chart need to be
adjusted accordingly.
While we do not have monitoring data at every location, contrary to
Earthjustice's comment, there are data that show the threshold wind
speed was exceeded not only in the Lemoore area but at other locations
in the central and southern SJV on September 22, 2006. The Lemoore
station showed the most intense wind speeds in the area and the data
are used to represent the conditions in the area centered around
Lemoore. The nearest meteorological station to Lemoore is the Santa
Rosa Rancheria monitoring station, located about 11 miles SE of
Lemoore. However, the fact that the winds at the SRR did not exceed the
threshold velocity does not prove that there were no wind speeds above
the threshold between Lemoore and Corcoran. We obtained wind data from
other meteorological stations in the central SJV such as Tranquility
(30 miles NW of Lemoore), Selma (20 miles NE of Lemoore), Kettleman
Hills (20 miles SSW of Lemoore), Hanford Municipal Airport (17 miles
east of Lemoore), Hanford (18 miles east of Lemoore) and Allensworth
State Park (43 miles SW of Lemoore). Wind speed data from these sites
are presented in the Table 6 below.
Table 6.--September 22, 2006 Morning Wind Speeds at Meteorological Monitoring Stations in the Central San Joaquin Valley
--------------------------------------------------------------------------------------------------------------------------------------------------------
Allensworth
Time (a.m. PST) Tranquility (hour/ Selma (hour/gust) Lemoore (hour/ Kettleman Hills Hanford Airport Hanford (hour/ State Park
gust) gust) (hour/gust) (hour/gust) gust) (hour)
--------------------------------------------------------------------------------------------------------------------------------------------------------
6:20............ 9/12.............. 6/7............... ND................ ND................ ND................ 4/10.............. ND
6:30............ 10/10............. 5/9............... ND................ ND................ ND................ 5/8............... ND
[[Page 14704]]
6:45............ 8/12.............. 5/7............... ND................ ND................ ND................ 5/8............... 3
7:00............ 9/11.............. 6/9............... 21................ 16/24............. 17/ND............. 5/7............... 6
7:20............ 13/12............. 7/6............... ND................ ND................ ND................ 5/11.............. 7
7:35............ 13/14............. 7/7............... ND................ ND................ ND................ 5/11.............. ND
7:45............ 14/14............. 8/9............... 28................ 17/24............. 15/ND............. 7/10.............. 38
8:05............ 15/19............. 10/10............. 26................ ND................ ND................ 8/12.............. 5
8:15............ 13/19............. 12/10............. 31................ ND................ ND................ 9/12.............. 20
8:30............ 21/20............. 14/14............. 28/35............. ND................ ND/26............. 9/17.............. 21
8:45............ 23/23............. 8/16.............. ND/35............. ND................ ND................ 7/18.............. 9
9:00............ 20/23............. 12/15............. 29/38............. 18................ 15/ND............. 5/21.............. 2
9:20............ 18/27............. 12/18............. 24/40............. ND................ ND................ 4/18.............. 35
9:35............ 21/25............. 9/15.............. ND................ ND................ ND................ 5/16.............. 6
9:45............ 17/25............. 6/16.............. ND/37............. ND................ ND................ 8/18.............. 2
10:05........... 17/24............. 9/13.............. 23/ND............. 20/27............. 10/ND............. 7/16.............. 15
10:15........... 17/26............. 5/13.............. ND................ ND................ ND................ 4/11.............. 3
10:35........... 17/23............. 7/7............... ND................ ND................ ND................ ND/13............. 9
10:50........... 14/23............. 8/12.............. ND/30............. ND................ ND................ ND/13............. 0
11:05........... 16/21............. 7/7............... 17/ND............. 17/32............. 10/ND............. ND/11............. ND
11:15........... 12/22............. 7/12.............. ND................ ND................ ND................ ND................ 8
11:30........... 14/20............. 1/9............... ND................ ND................ ND................ ND................ 10
11:35........... 15/23............. ND/8.............. ND/24............. ND/24............. ND................ ND................ ND
11:45........... ND/23............. 6/9............... ND................ ND................ ND................ ND................ 0
11:50........... ND/23............. ND/5.............. ND................ ND................ ND................ ND................ ND
12:00........... ND/16............. 0................. 14/............... 17/ND............. 10/ND............. ND................ ND
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowest/.
ND--No Data available.
Earthjustice includes data in its chart only from locations which
had recorded lower wind speeds on the morning of September 22, 2006. We
addressed the lower intensity winds at Corcoran and Bakersfield in our
proposed rule, and the fact that the winds between Lemoore and Corcoran
and Bakersfield were capable of keeping in suspension the particulate
matter that the winds at Lemoore had suspended. See 72 FR at 49052.
Earthjustice does not include data from the other meteorological sites
in the general area of the central SJV that show winds that were
comparable to those recorded at the Lemoore Naval Air Station
meteorological site. Data from these other meteorological sites, as
shown above, indicate that nearly all recorded hourly wind speeds on
September 22, 2006 were in excess of the threshold wind speed of 18 mph
between 6 a.m. and 12 noon PST. Recorded gusts at some of these sites
were also in the 20-30 mph range during the morning hours. It is likely
that there were other places along the path from Lemoore to Bakersfield
that experienced wind speeds above the threshold velocity but there
were no wind instruments to document it.
Therefore, Earthjustice's statement that none of the winds
experienced outside of northwest Lemoore were capable of eroding soils
is simply not true. Based on actual recorded wind data, wind speeds in
the central SJV on the morning of September 22, 2006 were high not just
in Lemoore but throughout this portion of the Valley. Moreover, as
pointed out above, even if the winds outside of Lemoore were not
capable of eroding soil, the winds between Lemoore and Corcoran and
Bakersfield were capable of keeping in suspension the particulate
matter that the winds in the area around Lemoore had entrained.
Comment 17: Earthjustice states that no attempt was made to explain
how high winds that began at 7 a.m. on September 22, 2006 caused
violating PM-10 levels at a monitor 25 miles away starting at 6 a.m.
Response 17: See responses to comments 10 and 11.
Comment 18: Earthjustice asserts that EPA failed to demonstrate
that the concentrations measured on September 22, 2006 could have been
caused by the wind-generated erosion of soils from agricultural and
industrial sources in the Lemoore area. Earthjustice states that all
EPA offered as evidence is a study establishing a threshold velocity at
which soil erosion may begin to occur, but that EPA has not analyzed
whether the study's threshold wind speed is appropriate for the Lemoore
area. Earthjustice argues that the scouring of soil by winds depends on
much more than simply the speed of the wind and that EPA has not
attempted to analyze factors pertinent to fugitive dust generation such
as the soil class and erodibility in the Lemoore area, the types and
stages of crop cover present at the time the winds occurred, the
specific activities occurring in the area that contributed to PM-10
concentrations, or the specific measures employed by sources to reduce
or prevent wind erosion. Earthjustice maintains that this information
should have been evaluated to help determine whether or not the winds
in Lemoore could have realistically generated the levels of PM-10
observed on September 22, 2006.
Response 18: EPA has demonstrated that the concentrations measured
on September 22, 2006 were caused by windblown dust generated in the
Lemoore area. As stated above in response to comment 10, the State's
documentation included a threshold wind speed needed to erode soils and
entrain the resulting particulate matter in the atmosphere. This wind
speed study was part of the 2002 CRPAQS Study. The wind speed study was
performed in Angiola, California, which is located about 8 miles SW of
Corcoran and 34 miles SW of Lemoore. Based on the soil map included in
the State's documentation, the soil type in Angiola is the same as
those in Lemoore and Corcoran. See ``Natural Event Documentation,
Corcoran, Oildale and
[[Page 14705]]
Bakersfield, California, September 22, 2006,'' San Joaquin Valley
Unified Air Pollution Control District, April 20, 2007 at 76. Thus the
threshold velocity at which soil erodes identified in the study is
appropriate for the Lemoore and Corcoran areas.
Reviewing the graphic in the State's documentation, we see that
crop types throughout the areas in question are predominantly field
crops. Id. at 77. Other sources in this rural portion of the SJV could
include, but are not limited to, agricultural activities, unpaved roads
and construction activity. These types of sources are all subject to
BACM. Id. at 32-33. These BACM are part of the approved serious area
PM-10 plan for the SJV. See 69 FR 30006. Therefore, EPA did in fact
evaluate the principal factors identified by Earthjustice, including
wind speed, sources and whether they were controlled. See also our
proposed rule at 72 FR 49051 and 49053.
Comment 19: Earthjustice states that EPA must find that the
documentation demonstrates a clear causal relationship between a
measured exceedance and the alleged event. In this respect,
Earthjustice, relying on a declaration of Jan Null (Null declaration),
argues that the District's documentation concocts a barely-plausible
story of severe scouring by winds not much greater than the alleged
minimum velocity for entrainment, followed by rapid transport from one
remote west-Valley location (Lemoore) down to Corcoran, where huge
amounts of particulate matter were deposited on the monitor in order to
cause violations, yet enough pollution was kept entrained by much
slower winds to continue on for 60 miles down to Bakersfield and
Oildale in substantial enough quantities to also cause violations in
those locations. Earthjustice concludes that this ``story'' is
unsupported by reliable meteorological evidence.
Response 19: As discussed in EPA's proposed rule (72 FR 49046) and
in responses to comments 11 and 16, the State did provide reliable
meteorological data to support its demonstration that winds in the
central and southern SJV were of the appropriate intensity and
direction to cause and transport fugitive dust to the affected monitors
at Corcoran and Bakersfield. EPA relied on these data, as well as other
publicly available data, to concur with the State's request to find
that the exceedances of the NAAQS on September 22, 2006 were due to an
exceptional event.
Furthermore, Earthjustice mischaracterizes the data used to support
this action. It is not the case that winds were not much greater than
the threshold wind speed of 18 mph; rather they were at times
significantly higher and widespread in the central SJV. See Table 6
above. Winds between Lemoore and Corcoran were of the appropriate
direction and intensity to transport windblown dust to Corcoran, 25
miles away. Winds in the areas south of Corcoran and north of
Bakersfield were of sufficient intensity to transport suspended PM-10
the 55 miles from Corcoran to Bakersfield.\27\ The timing, direction
and intensity of the winds and hourly PM-10 concentrations at
Bakersfield all support the demonstration of transport presented by the
State. Based on the weight of evidence presented, EPA has concluded the
State's documentation shows a clear causal relationship between the
wind event and the exceedances in contrast to the ``barely-plausible
story'' Earthjustice alleges.
---------------------------------------------------------------------------
\27\ There may have been some deposition and dispersion of the
dust plume, as discussed in our proposal at 72 FR at 49052, but
enough material remained suspended to impact the Bakersfield area.
The fact that the 24-hour average PM-10 concentrations in
Bakersfield and Oildale were 157 [mu]g/m\3\ and 162 [mu]g/m\3\
compared to the 215 [mu]g/m\3\ recorded at Corcoran certainly
indicates that some deposition or dispersion occurred along the 55
mile pathway.
---------------------------------------------------------------------------
Comment 20: Earthjustice states that the Figure 1 in the Null
declaration shows that winds originating in Lemoore at 7 am, which is
when the data in the record show elevated winds began, may have
traveled to Corcoran, arriving around noon. However, Earthjustice
states that because the Corcoran monitor began reading exceedances of
the PM-10 standard at 6 a.m., EPA cannot claim the winds caused the
Corcoran exceedance.
Response 20: See our responses to comments 10 and 11.
Comment 21: Earthjustice claims that the Figures 1, 2 and 3 in the
Null declaration show that the winds that did reach Corcoran proceeded
northeast toward the Sierra foothills and did not move in the direction
of Bakersfield.
Response 21: As discussed in our response to comment 11 above, EPA
assumed a more realistic three-dimensional approach to using the
HYSPLIT model than Earthjustice's two-dimensional approach. We also
used a small range of starting points for our HYSPLIT runs, recognizing
that simply because the available Lemoore meteorological data were from
a single point at the Lemoore Naval Air Station, the data from that
point represent meteorological conditions over a wider area. See
footnote 11 above.
Based on our more realistic inputs, we initiated three HYSPLIT
runs, one starting half way between Lemoore and Kettleman City (about
11 miles southwest from Lemoore), one at Lemoore, and one about 11
miles northeast of Lemoore. EPA chose these two different starting
locations outside of Lemoore because, based on the trajectory model,
they more precisely depict the potential source regions for Corcoran,
which is more east than south of Lemoore, and Bakersfield, which is
more south than east of Lemoore. Since the Lemoore station can be
considered representative of a larger area than Lemoore itself, the
starting locations are considered part of the Lemoore area and dust was
entrained from that entire area. Also, in support of that assumption,
Hanford, which is about 15 miles east northeast of Lemoore, and
Kettleman Hills, about 22 miles southwest of Lemoore, reported wind
speeds above the threshold for the entrainment of dust.
The results of our HYSPLIT runs show that from Corcoran and
eastward, some of the dust may have been transported more towards the
Sierra foothills, but west of Corcoran the dust was transported
southward towards Bakersfield. See Figures 1, 2, and 3. These results
are in general agreement with Jan Null's statement that:
* * * winds out of Kettleman City continued down the western-
most side of the San Joaquin Valley, essentially following the
contours of the Coastal Range. This is not unusual behavior for
winds on the west side of the Valley, which are generally faster
than winds in the rest of the Valley due to the orientation of the
Sacramento and San Joaquin Valleys.
Null declaration at 11. Between Lemoore and Kettleman City, the winds
were in transition from heading towards the east near Corcoran and
following the Coastal Range as happened around Kettleman City. This
caused the winds in a portion of that transition area to go in a direct
path towards Bakersfield. In contrast to EPA's inputs to the HYSPLIT
model, the inputs used by Jan Null did not reflect the wind flow
structure in the Valley and did not demonstrate a comprehensive view of
the meteorological events that took place during that day.
Comment 22: Earthjustice believes that EPA was ``dazzled'' by the
District's use of the HYSPLIT model even though the model is not an
appropriate tool for post hoc simulation of localized meteorology and
EPA did no analyses of its own. Earthjustice further states that the
District's single run does not show the connection between Lemoore
winds and the violating monitors that EPA apparently thinks it does.
[[Page 14706]]
Response 22: See our response to comments 10, 11 and 21.
Comment 23: Earthjustice maintains that the winds just south of
Lemoore, in and around Corcoran and between Corcoran and Bakersfield
never exceeded the ``alleged'' threshold velocity to entrain dust and
the winds originating in Lemoore that did exceed such threshold could
not have carried sufficient particles of PM on to Bakersfield and
Oildale. Earthjustice concludes therefore that the timing, wind
trajectories and the basic physics of wind movement do not support a
causal connection between the Lemoore winds and the September 22, 2006
exceedances.
Response 23: See responses to comments 11 and 16.
Comment 24: Earthjustice notes that the District highlights a
single data point showing sustained winds of 15.2 mph for one hour in
Alpaugh. Earthjustice believes this is troubling because the District
is relying on data from the California Irrigation Management
Information System (CIMIS) monitoring network that the T & B Systems
Report says should be used with ``extreme caution.'' Earthjustice also
believes that it is suspicious that the District puts forth data from
this source while simultaneously providing almost none of the data it
collects from its own meteorological sensors which are collocated with
the monitors that record PM-10 concentrations.
Response 24: Earthjustice quotes from the T & B Systems Report
without providing the context of the warning to use the data with
``extreme caution.'' In its report, T & B Systems state:
CIMIS--This data set should be used with extreme caution. Two
significant issues regarding the CIMIS data were noted. First, the
fact that wind measurements are made at 2 meters instead of 10
meters appears to result in the reported wind speeds decreasing by
about 30 percent relative to those made at 10 meters. This can be
corrected, for the most part, by using the standard power law
adjustment. Second, the results brought about significant questions
about the alignment of the wind direction system, with possible
misalignments as much as 30[deg] noted. This potential problem was
noted at a significant number of sites investigated. The QA program
for the CIMIS network is not known.
``T & B Systems Contribution to CRPAQS Initial Data Analysis of Field
Program Measurements, Final Report Contract 2002-06,'' Technical &
Business Systems, Inc., November 9, 2004 at 3.
The issue of the height of the measurements taken at CIMIS'
meteorological stations was addressed by the State in its
documentation.\28\ Winds measured at two meters above ground level
(AGL) are generally lower than those measured at the standard 10
meters.
---------------------------------------------------------------------------
\28\ ``Addendum, Natural Event Documentation, Corcoran, Oildale
and Bakersfield, California, September 22, 2006,'' May 23, 2007 at
13.
---------------------------------------------------------------------------
Regarding the alignment of the wind direction system, there were
many other meteorological stations that provided data on wind direction
and these showed that the winds were predominantly from the north and
northwest on September 22, 2006.
Any uncertainty regarding the quality assurance for the CIMIS data
would carry more weight if we were relying solely on the CIMIS data.
Most of the meteorological data included in the State's documentation
\29\ as well as the additional data obtained by EPA \30\ and used to
evaluate this exceptional event demonstration were from the District's
meteorological stations and National Weather Service meteorological
networks. Since the District does not operate any monitoring stations
between Corcoran and Bakersfield, it did not have any District-
collected meteorological data for this region.
---------------------------------------------------------------------------
\29\ ``Natural Event Documentation, Corcoran, Oildale and
Bakersfield, California, September 22, 2006,'' San Joaquin Valley
Unified Air Pollution Control District, April 20, 2007; ``Addendum,
Natural Event Documentation, Corcoran, Oildale and Bakersfield,
California, September 22, 2006,'' San Joaquin Valley Unified Air
Pollution Control District, May 23, 2007.
\30\ Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowest/.
---------------------------------------------------------------------------
Comment 25: Earthjustice believes that the District did little more
than a blind search for the areas of the SJV that experienced winds
that exceeded the ``alleged'' entrainment level and then concluded that
pollution on September 22, 2006 must have originated from that area.
Response 25: EPA believes that the State and EPA conducted a
thorough evaluation of the possible cause of the September 22, 2006
exceedances and considered potential sources, conditions and control
measures at the time of the exceedances. We discuss in additional
detail in our response to comment 16 the fact that a number of
locations in the central SJV besides Lemoore experienced high winds on
that day. After a consideration of the most likely cause of the
exceedances and after evaluating all the circumstances, the State
concluded that the unusually high winds in the Lemoore area caused the
exceedances in Corcoran and Bakersfield on September 22, 2006. The
State then established in its documentation the causal connection
between the winds in the Lemoore area and the exceedances at Corcoran
and Bakersfield.
Comment 26: Earthjustice asserts that neither the District nor EPA
offers any basis for the statement in the proposed rule at 72 FR 49051
that ``wind speeds [in Corcoran], though not sufficient to erode dust,
were sufficient to keep entrained and transported dust from the high
winds at Lemoore suspended for the period during which the exceedances
occurred.'' Earthjustice further asserts that because winds 10 miles
southeast of Lemoore at the SRR never exceeded the entrainment
threshold and no other relevant location outside of the area northwest
of Lemoore experienced erosive winds, there is very little basis for
the conclusion that a clear causal relationship exists between dust
entrained in Lemoore and violations of the standard in Corcoran,
Oildale and Bakersfield.
Response 26: See responses to comments 10, 11, 15 and 16.
Comment 27: Earthjustice asserts that EPA fails to show that the
exceedances at Corcoran, Bakersfield and Oildale were outside normal
historical concentrations. Earthjustice claims that dust-intensive
agricultural activities occur in the fall and that none of the
September 22, 2006 exceedances are significantly beyond the normal
fluctuating range of air quality concentrations in the SJV.
Earthjustice presents a chart that it says demonstrates that the
September 22, 2006 readings are within the historical range of PM-10
concentrations observed over the past 15 years during the fall season.
Response 27: See our response to comment 12 above.
Comment 28: Earthjustice states that EPA suggests in the
Exceptional Events Rule that a contemporary comparison of all
seasonally-adjusted data is appropriate for determining historical
frequency of the measurements in question. However, Earthjustice says,
because fall is the season with the highest PM-10 concentrations, the
comparison is most appropriately made by looking at historical data
from September through November. Earthjustice claims that because the
District's documentation limits its comparison to September
measurements over a 7 year period, the result is a ``typical value''
based only on the ``relatively good days monitored.''
Response 28: See our response to comment 12 above.
Comment 29: Earthjustice maintains that EPA asserts that because
the September 22, 2006 measurements were higher than what the District
claims is
[[Page 14707]]
the ``typical value'' for the month of September, these violations must
have been caused by an exceptional event. Earthjustice claims that with
this argument EPA is saying that any PM-10 exceedance should be ignored
as exceptional which is an absurd assumption that would render the
NAAQS meaningless.
Response 29: EPA did not decide to exclude the data from September
22, 2006 from its attainment finding simply because the data were
outside of the typical range of values normally seen in these areas.
The EER has a number of criteria that need to be met in order for us to
concur with a State's request to exclude data from consideration,
including a demonstration that the event affected air quality, a causal
connection between the event and the exceedance value recorded, an
analysis demonstrating that the recorded exceedance was outside the
normal fluctuation of the data, and a demonstration that ``but for''
the event the exceedance would not have occurred. EPA evaluates how the
State meets all of these criteria, in addition to the procedural
requirements of the EER and determines, based on the weight of the
totality of the evidence presented, whether to concur with the State's
request. In this case, EPA believes that the State has met the
``weight-of-evidence'' standard and has demonstrated that the cause of
the exceedances on September 22, 2006 was a high wind exceptional
event. See also our response to comment 12.
Comment 30: Earthjustice states that if EPA had compared the
September 22, 2006 data to data from other days on which exceedances
occurred, it would have found that the September 22, 2006 readings are
typical of bad air days in the fall in the SJV and therefore would not
have been able to dismiss these violations as ``in excess of normal
fluctuations.''
Response 30: See response to comment 12.
Comment 31: Earthjustice states that it reviewed EPA's AQS reports
of monitoring data from the past ten years and found that in Corcoran,
50 percent of all FRM readings showing elevated levels of PM-10 occur
in September and October and that 95 percent occur in the period from
September to January. Earthjustice states that although the numbers are
lower in Bakersfield and Oildale, with 31 percent and 29 percent of
elevated PM-10 readings, respectively, occurring in September and
October, these numbers do not paint the picture of exceptionality the
District and EPA claim. Instead, Earthjustice declares, these numbers
confirm that the concentrations recorded on September 22, 2006 were
within the normal historical range of PM-10 concentrations experienced
in the central and southern SJV during the fall PM season when
concentrations are historically at their highest.
Response 31: As discussed in our response to comment 12, EPA
analyzed data from these sites and determined that the concentrations
recorded on September 22 and October 25, 2006 were well outside the
normal historical fluctuation of data normally recorded at these sites.
In its comment, Earthjustice analyzes what it states are ``elevated
levels'' of PM-10 concentrations that were recorded at the Corcoran,
Oildale, and Bakersfield-Golden State Highway sites. Earthjustice
asserts that an ``elevated level'' is ``defined by EPA'' as 90 [mu]g/
m\3\ or greater.\31\ This is not the case. For the source of its
definition, Earthjustice cites a Federal Register notice in which EPA
proposed to approve a PM-10 maintenance plan for Wallula, Washington.
In that proposed rule the 90 [mu]g/m\3\ or greater was a figure
employed by the Washington State Department of Ecology for use in
modeling a PM-10 maintenance demonstration. 70 FR 38076 (July 1, 2005).
EPA did not endorse or adopt this level as a definition of what
constitutes ``elevated levels'' of PM-10 for the purposes of performing
an analysis of historical fluctuations for the EER, and Earthjustice's
evaluation of ``elevated levels'' at the SJV monitoring sites is not
based on an EPA definition of what constitutes ``elevated levels'' for
this purpose.
---------------------------------------------------------------------------
\31\ EC at 6, footnote 16.
---------------------------------------------------------------------------
Comment 32: Earthjustice claims that the ``but for'' test requires
a showing that without the winds scouring the soils near Lemoore, the
monitors in Corcoran, Bakersfield, and Oildale would not have recorded
violations of the PM-10 standard and that such a showing cannot be
made. Specifically, Earthjustice asserts that the monitor in Corcoran
was violating the PM-10 standard on September 22, 2006 before the winds
in Lemoore even picked up. Earthjustice states that Table 3 of the
District's April 20, 2007 documentation shows that the continuous
monitor in Corcoran was recording concentrations in excess of 150
[mu]g/m\3\ starting at 6 a.m. Earthjustice further maintains that Jan
Null in his declaration states that there is no way the winds in
Lemoore could transport entrained dust instantaneously from Lemoore to
Corcoran.
Response 32: We address these issues in our responses to comments
10, 11, 16 and 21. In our proposed rule we also discussed how the State
met the ``but for'' criteria. 72 FR at 49053.
Comment 33: Earthjustice further asserts that the winds in Corcoran
never even got above 11 miles per hour, so local wind entrainment of
particulate matter is not a factor. Earthjustice concludes that
activities in and around Corcoran must have been responsible for the
high PM-10 concentrations on September 22, 2006, not winds from
Lemoore.
Response 33: We addressed the lower wind speed issue in Corcoran in
our proposed rule at 72 FR 49052 and also in our responses to comments
10 and 15. As we discussed in the proposed rule, the lower wind speeds
in Corcoran do not preclude the transport of dust from the areas
northwest of Corcoran. The wind data from September 22, 2006 show high
winds in the area centered around Lemoore. It was this area northwest
of Corcoran that contributed PM-10 to the air parcel that impacted the
monitors at Corcoran and Bakersfield. While any sources in the local
area represented by the Corcoran monitor may have contributed some PM-
10 to the total 24-hour average, it was the wind-generated dust from
the area of Lemoore that contributed enough PM-10 to cause the monitor
to record an exceedance of the 24-hour PM-10 NAAQS.
Given the evaluation of all information and circumstances
surrounding the exceedance at the Corcoran monitor on September 22,
2006, the weight of evidence supports the conclusion that the windblown
dust from the area of Lemoore rather than contributions from sources in
the area represented by the Corcoran PM-10 monitor were the ``but for''
cause of the exceedance.
Comment 34: Earthjustice argues that, even if 6 hours worth of
readings from the Corcoran continuous monitor were removed starting at
11 a.m., in order to account for the 6 hours during which winds in
Lemoore exceeded the alleged threshold velocity, there is still a
violation of the PM-10 standard. Therefore, Earthjustice concludes,
there is no way the District can argue and EPA can concur that winds
from Lemoore were the cause of the violation of the PM-10 standard in
Corcoran on September 22, 2006.
Response 34: As discussed in the preamble to the EER, EPA's
historical practice has been to exclude a daily measured value in its
entirety when an exceptional event causes that value. See 72 FR at
13572. EPA is not aware of the existence of precise and universally
applicable techniques that are administratively and technically
[[Page 14708]]
feasible and that could support partial adjustment of air quality data.
Thus, the approach suggested by Earthjustice is not viable and is not
permitted by the EER except in some very limited cases not applicable
here. See also response to comments 10.
Moreover, Earthjustice suggests that the winds from Lemoore began
affecting the Corcoran monitor at 11 a.m. In fact the Lemoore area
experienced winds higher than the threshold wind speed beginning at 6
a.m. PST and these winds likely began affecting the monitor at Corcoran
between 7 and 8 a.m. PST (the value reported for 7 a.m. PST). See
response to comment 10. When the winds at Lemoore decreased to levels
below the threshold wind speed at 2 p.m. PST, the dust entrained in the
atmosphere most likely still continued to impact the Corcoran monitor,
though we see a leveling off and then gradual decrease in hourly PM-10
concentrations from that point forward. See Table 3 above in our
response to comment 10. We further addressed this timing question by
performing our own HYSPLIT analyses. See response to comment 11 above.
The result of our analysis of the winds on September 22 supports the
State's demonstration that winds originating in the area around Lemoore
starting at 6 a.m. PST could have transported dust and impacted the
Corcoran monitor within one to two hours. See Figures 1 and 2.
Earthjustice appears to assume that particles are deposited as soon
as winds decrease below the threshold speed for entrainment; in fact,
PM-10 particles remain in suspension for many hours after being
entrained and, as in the case of Corcoran, continued to affect
concentrations recorded at the monitor until the early evening hours of
September 22, 2006. Thus, Earthjustice assumes that the windblown dust
started to affect the concentrations monitored at Corcoran many hours
later than it did in fact, and that it ceased to impact the monitor
many hours before it did in fact. Thus EPA believes that the impact on
the monitor started earlier and ended later than Earthjustice contends,
and was thus the ``but for'' cause of the exceedance.
Comment 35: Earthjustice maintains that there is no support for the
claim that but for the winds originating in Lemoore, the monitors in
Bakersfield and Oildale would not have exceeded the PM-10 standard.
Earthjustice states that Jan Null shows in Figures 1, 2 and 3 in his
declaration that the winds originating in Lemoore may have reached
Corcoran at some point in the day, but they certainly did not continue
on to Bakersfield and Oildale. Earthjustice states that the
trajectories of winds out of Lemoore and Corcoran were decidedly away
from Bakersfield and could not have carried particulate matter to
Bakersfield and Oildale to cause the violations of the standard seen in
these locations. Earthjustice states that Figure 4 in Jan Null's
declaration shows that, in fact, any winds arriving in Bakersfield by 1
p.m. were slow and moving in a circular pattern up from the southwest.
Further, Earthjustice asserts that, as illustrated in Table A-1 of the
District's May Addendum to its April 20, 2007 documentation, wind
speeds in the Bakersfield area never reached speeds capable of eroding
soils.
Response 35: We have previously addressed the issue of dust
transport to Bakersfield in our responses to comments 10, 11, 15, 16
and 21. EPA does not contend that the wind speeds in Bakersfield
reached the speeds necessary to erode and entrain dust, but rather that
windblown dust from the area beginning in Lemoore and moving south
affected the monitors in Bakersfield.
The trajectory calculation that Jan Null used for Bakersfield was
not illustrative of the complete meteorological scenario. Again, he
used a single trajectory calculation starting at zero meters height
which does not account for the third dimension of height of the dust
above ground level. In HYSPLIT runs performed by EPA, forward
trajectory calculations within the mixed layer starting between Lemoore
and Kettleman Hills show transport directly to Bakersfield within 7
hours.
In addition, the circular wind pattern or eddy near Bakersfield
discussed by Earthjustice was produced by a HYSPLIT analysis using a
backward trajectory. However there appears to be a discrepancy between
forward trajectories and backward trajectories produced by the HYSPLIT
model. In source-receptor determinations, forward trajectories are
considered more appropriate in determining precise locations of sources
because they more accurately account for where the weather is coming
from. EPA's forward trajectories did not show any indication of an
eddy. The eddies that Earthjustice states occurred around Bakersfield
are around 15 km in size for September 22, 2006. Since the EDAS
meteorological data used for the trajectories has 40 km spacing between
each grid point or meteorological data point, it is not of high enough
resolution to accurately represent an eddy in the 15 km size range.
There is too much uncertainty to conclude that there is an eddy because
it is less than one grid cell spacing in dimension and would be
considered a sub-grid scale feature. Thus, EPA's HYSPLIT runs, using
more appropriate height levels in the atmosphere and forward
trajectories, support the conclusion that the winds transported dust
from the Lemoore area and caused the exceedances recorded at the
monitors in the timeframe of the exceedances.
Comment 36: Earthjustice argues that, in evaluating the ``but for''
demonstration, no attempt was made to determine which of the many
diverse sources that contribute to particulate matter concentrations in
the SJV might have been contributing to the pollution load and in what
quantities on September 22, 2006. Earthjustice concludes that for EPA
to declare that no ``unusual activities'' were taking place on this day
is to say that the same dust-generating sources that have always caused
periodic violations of the standards in the fall were again responsible
for exceedances.
Response 36: See responses to comments 6, 12 and 14.
3. Comments Specific to October 25, 2006--Corcoran and Bakersfield
Comment 37: Earthjustice states that the documentation for the
exceedances on October 25, 2006 is remarkably similar to that of
September 22, 2006, and as such, suffers from the same significant
flaws. Earthjustice also states that since the meteorology for both
days was very similar, much of its analysis for September 22, 2006 also
applies to October 25, 2006. Earthjustice provides a chart which it
contends shows that wind speeds in Lemoore on October 25 were very
similar to wind speeds on September 22. With respect to this chart,
Earthjustice asserts the following:
* * * there was a period of several hours during which the
alleged wind speed threshold was exceeded in northwest Lemoore at
the Naval Air Station monitor, though again wind speeds at the Santa
Rosa Rancheria monitor only 10 miles southeast never reached that
threshold. * * * Winds in Corcoran never got above 11.3 miles per
hour and Bakersfield, likewise, did not exceed the District's
alleged entrainment threshold with maximum winds just under seven
miles per hour. * * * Further, the District can point to no data
between Lemoore and Bakersfield that show winds capable of
entraining dust, offering instead only data from CIMIS stations
located far to the north and west that experienced higher wind
speeds on October 25, 2006. As has already been established by Mr.
Null, higher wind speeds on the west side of the Valley along the
Coastal Range are not unusual due to the orientation of the
Sacramento and San Joaquin Valleys. * * *
Response 37: To the extent there are similarities between
Earthjustice's
[[Page 14709]]
analyses for September 22 and October 25, 2006, EPA's responses to
comments regarding September 22 are also applicable.
In addition, EPA notes that the wind speeds in the central SJV, as
represented by the meteorological monitoring station at Lemoore, on
October 25 were quite high, reaching hourly average speeds of 31 mph
and gusts of up to 40 mph, and were sustained at levels above the
threshold wind speed for 11 hours (5 a.m. to 3 p.m. PST),\32\ as shown
in Table 5 above. We do not contend that the wind speeds in the
vicinity of Corcoran and Bakersfield were sufficient to entrain dust
but, like September 22, 2006, the windblown dust generated in the
Lemoore area in the central SJV was the ``but for'' cause of the
exceedances recorded in Corcoran and Bakersfield on October 25, 2006.
Moreover, the wind speeds that occurred in between Lemoore and Corcoran
and Bakersfield were of sufficient speed to transport the entrained
dust from Lemoore to the affected areas. Id.
---------------------------------------------------------------------------
\32\ As discussed in response to comment 10 above, the
meteorological data for Lemoore must be adjusted to correct for
Daylight Savings Time.
---------------------------------------------------------------------------
Earthjustice again selectively presents meteorological data to
support its own position and neglects to include other data that
support the State's demonstration. From the data supplied by the State
in its documentation as well as additional publicly available data, it
is clear that wind speeds in Lemoore, as well as throughout the central
San Joaquin Valley, were either in excess of the threshold wind speed
for entrainment (18 mph) or of sufficient intensity to transport dust
from the Lemoore area to Corcoran and the southern SJV. See Table 7
below.
Table 7.--October 25, 2006 Daytime Wind Speeds at Meteorological Monitoring Stations in the Central San Joaquin Valley
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hanford Kettleman
Hour Mendota Tranquility Lemoore Airport Hills (hour/ Alpaugh Wasco (hour/
(hour/gust) (hour/gust) (hour/gust) (hour/gust) gust) (hour) dir/gust)
--------------------------------------------------------------------------------------------------------------------------------------------------------
6............................................................ 12/ND 9/15 22/30 17/23 11/21 3.5 2/SW/3
7............................................................ 15/20 10/17 22/32 15/ND 20/28 2.9 0
8............................................................ 18/25 13/19 26/36 17/ND 15/27 5.6 7/NNW/15
9............................................................ 17/30 20/22 29/39 24/29 19/32 16.9 5/NNE/18
10........................................................... 22/31 17/21 31/37 20/28 25/35 16.5 9/N/22
11........................................................... 22/30 15/20 30/40 15/24 25/35 16.8 7/N/15
12........................................................... 21/28 17/20 28/38 12/21 24/45 15.6 6/N/16
13........................................................... 20/28 15/23 26/35 12/ND 25/34 14.8 8/N/16
14........................................................... 18/29 18/19 22/31 9/ND 21/35 13.2 2/NNE/10
15........................................................... 12/23 10/18 20/26 12/18 22/33 13.3 ND/N/12
16........................................................... 15/20 8/17 14/ND 8/16 15/28 12.7 3/N/7
17........................................................... 8/17 4/10 3/ND 8/ND 9/22 6.5 2/N/ND
18........................................................... 5/6 1/5 6/ND 6/ND 10/14 4.4 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: Mesowest historical meteorological data, Mesowest, http://www.met.utah.edu/mesowest/.
ND--No Data available.
South of Corcoran, wind speeds measured at Alpaugh,\33\ 15 miles
SSE of Corcoran and 44 miles NW of Bakersfield, were close to exceeding
the threshold wind speed and as such were sufficient to transport
particulate matter from the Lemoore area to Bakersfield as discussed
above and in our proposed action. Furthermore, meteorological data from
a station in Wasco, 40 miles SSE of Corcoran and 25 miles NW of
Bakersfield and not part of the CIMIS network, recorded data that
indicate that the daytime winds, while not high enough to erode soils,
were predominantly from the north.
---------------------------------------------------------------------------
\33\ See response to comment 24.
---------------------------------------------------------------------------
Comment 38: Earthjustice states that like the documentation for
September 22, 2006, the District's documentation for the alleged
October event also fails to analyze the actual ability of the area to
generate particulate matter concentrations in quantities great enough
to cause the exceedances, fails to provide anything more than anecdotal
evidence of activity levels and compliance with dust controls, and
therefore fails to demonstrate that the winds in Lemoore affected air
quality at all. Earthjustice states that, like the case for the
September 22 demonstration, a claim that the wind entrained significant
amounts of dust requires looking at more than just the wind speeds in
the area. There are many factors that EPA and the District failed to
support with any reliable and accurate data, starting with whether
there was any dust available to be entrained.
Response 38: See responses to comments 6, 14 and 18. As is the case
with the September 22, 2006 documentation, the State has evaluated a
variety of factors and circumstances to demonstrate that windblown dust
caused the exceedances on October 25. See ``Natural Event
Documentation, Corcoran and Bakersfield, California, October 25,
2006,'' San Joaquin Valley Unified Air Pollution Control District,
April 23, 2007 at section 7.
The State also provided information on the inspection and
compliance activities that were conducted on October 25, 2006. Section
9.2 of the State's documentation lists the number of inspections and
the location of inspection activity and indicates that the District was
actively enforcing its rules on October 25, 2006. Two newspaper
accounts of the high winds that occurred on October 25, 2006 provide
independent verification of meteorological conditions. This type of
documentation has been historically used to support these types of
exceptional events requests. EPA's EER states that the simplest
demonstrations could consist of newspaper accounts or satellite images
to demonstrate that an event occurred together with daily and seasonal
average ambient concentrations to demonstrate an unusually high ambient
concentration level, which is clearly indicative of an exceptional
impact. 72 FR at 13573.
Comment 39: Earthjustice states that, as explained in its comments
for September 22, 2006, the generation of particulate matter from winds
of the
[[Page 14710]]
type experienced on October 25, 2006 could have been controlled or
prevented had reasonable controls been required of dust-producing
sources. Earthjustice believes that the fact that the District is
trying to blame winds only slightly above the alleged wind speed
threshold, and significantly below the velocities at which the
aforementioned controls stop being effective, suggests that either
winds could not have entrained dust or the reasonable measures
referenced in the proposal were not actually in place at the time of
the event.
Response 39: See responses to comments 5, 6 and 7. The winds in the
Lemoore area on October 25 were not ``slightly above'' the wind speed
threshold but rather included sustained high winds between 26 and 31
mph with gusts ranging from 26 to 40 mph. These wind speeds were
clearly sufficient to entrain and transport PM-10.
Comment 40: Earthjustice states that high winds entraining dust may
qualify as a natural event, but it also believes the source of the dust
is of equal importance under the law. Earthjustice states that EPA
admits that on October 25, 2006, the wind-entrained particulate matter
originated from anthropogenic sources such as agricultural and
industrial activities, but that under the EER, only ``an event in which
human activity plays little or no direct causal role'' can be
considered a natural event. Earthjustice states that Congress did not
intend for exceptional events to include sources that are caused by
human activity. Alternatively, Earthjustice states that the source of
the dust cannot be considered a non-recurring human activity, as
agricultural and industrial activities are a constant source of
emissions in the Valley.
Response 40: See response to comment 5. Also, regarding
Earthjustice's argument that dust from agricultural and industrial
activities cannot be considered a non-recurring human activity because
these activities are a constant source of emissions in the Valley, EPA
does not consider (and has not stated anywhere) that normal
agricultural and industrial activities are ``non-recurring human
activity'' because such human activities often recur on a regular
basis. By contrast, examples of non-recurring human activities may
include major construction projects such as highways if they meet the
criteria and requirements established in the EER. However, a recurring
natural event such as a high wind event may entrain dust from
anthropogenic sources. The entrainment of dust from ``reasonably
controlled sources'' such as agricultural sources does not convert a
natural event that qualifies as a high wind event into a recurring
human activity which appears to be the result Earthjustice is seeking.
Comment 41: Earthjustice states that, like the September 22, 2006
documentation, the District did not provide the requisite amount of
time for public comment on its October 25, 2006 documentation and did
not re-publish its final documentation after radically changing its
rationale. These procedural deficiencies alone should give EPA pause in
considering the District's requests to flag this data.
Response 41: See response to comment 8.
Comment 42: Earthjustice states that since the meteorology on
October 25, 2006 is so similar to that of September 22, 2006, it is not
surprising that a causal connection cannot be established for October
25 either. Earthjustice points out that the Corcoran monitor began
reading concentrations above the national standard at 6:00 am, the same
time that the winds in Lemoore, 25 miles away, began exceeding the
District's alleged wind speed threshold at the same time. Earthjustice
believes that it should go without saying that it is not possible for
winds in Lemoore to transport entrained dust to Corcoran
instantaneously, which is what would have to be the case if we are to
believe the District's claims that those winds caused the exceedances
in Corcoran, and that therefore, something other than the Lemoore winds
caused the initial exceedances recorded at that monitor.
Response 42: See responses to comments 10 and 11.
Comment 43: Earthjustice states that even if we were to assume that
the winds carried dust from Lemoore to Corcoran, the trajectory of
those winds does not support the conclusion that the dust then moved
down to Bakersfield. Earthjustice cites Figure 7 in the Null
declaration which shows that winds originating in Lemoore moved on a
due-east path toward Hanford and Corcoran and continued on toward the
Sierra foothills. Jan Null uses HYSPLIT to determine the source of wind
parcels arriving in Bakersfield at noon, which is approximately when
the exceedances began, and shows that the same slow eddy effect that
occurred on September 22, 2006 was also occurring in Bakersfield on
October 25, 2006, which means that the winds impacting Bakersfield
during the time of the exceedances were coming in slowly from the
southwest. Figure 8 in the Null declaration.
Response 43: As discussed in our responses to comments 11 and 21
above, EPA assumed a more realistic three dimensional approach to using
the HYSPLIT model than did Jan Null. We also used a small range of
starting points for our HYSPLIT runs, recognizing that although the
available Lemoore meteorological data were from a point located at the
Lemoore Naval Air Station, the data represent conditions over a wider
area. See footnote 11 above.
As with our analysis of the September 22, 2006 event, we initiated
three HYSPLIT runs for October 25, 2006, one starting half way between
Lemoore and Kettleman City (about 11 miles southwest from Lemoore), one
at Lemoore, and one about 11 miles northeast of Lemoore. On October 25,
2006, the HYSPLIT trajectory presented by Null in Figure 7 of his
declaration indicates that the winds starting in Lemoore went to the
east southeast. However, EPA's HYSPLIT runs initiated half way between
Lemoore and Kettleman City, northwest of Corcoran, demonstrate that the
winds continued down the SJV towards Bakersfield, along a path just
west of Corcoran. See Figures 5 and 6 above. Between Lemoore and
Kettleman City, the winds were in transition from heading towards the
east near Corcoran and following the Coastal Range as happened around
Kettleman City. This caused the winds in a portion of that transition
area to go in a direct path towards Bakersfield. See Figure 5.
For Bakersfield, Null used a trajectory in Figure 8 of his
declaration at zero meters height to show the same eddy effect
occurring on October 25 as on September 22. Again, this height does not
take into account dust mixing up into the atmosphere. In EPA's HYSPLIT
runs, more appropriate forward trajectories were used which showed that
dust coming from the Lemoore area could have reached Bakersfield within
about 6 hours. See Figure 6. They also did not show any indication of
the eddy effect near Bakersfield that Earthjustice found with back
trajectories. Id. and response to comment 35. This supports the
conclusion that dust-laden winds from the Lemoore area reached
Bakersfield on October 25, 2006 consistent with the impacts reflected
at the Bakersfield monitor.
Comment 44: Earthjustice states that while the District and EPA
cite wind speeds averaging 12 miles per hour in Alpaugh, an area 15
miles south of Corcoran, neither agency provides a basis for concluding
that such winds could transport and keep suspended the plume of
entrained dust that was allegedly carried to Bakersfield, nor do they
explain how the evidence provided
[[Page 14711]]
even suggests such transport could have taken place.
Response 44: See responses to comments 11, 15 and 43. EPA finds
that the documentation does establish a clear causal relationship
between the winds in Lemoore and the exceedances in Corcoran and
Bakersfield. See ``Natural Event Documentation, Corcoran and
Bakersfield, California, October 25, 2006,'' San Joaquin Valley Unified
Air Pollution Control District, April 23, 2007. Earthjustice neglects
to consider that the CIMIS data need to be adjusted, as discussed in
the State's documentation, due to the fact that CIMIS stations collect
data at 2 meters above ground level as opposed to the standard 10 meter
height. Id. at 25. See also response to comment 24. When this
adjustment is made, we can see that the wind speeds at Alpaugh would
have been approximately 25 percent higher at 10 meters than at 2
meters. Winds at nearly 17 mph were recorded from 9 a.m. to 11 a.m.
PST, dropping to between 15 mph and 13 mph between 12 p.m. and 3 p.m.
PST. The lower wind speeds recorded at stations farther south, such as
Shafter and Arvin, are consistent with the State's demonstration that
after the winds in the central SJV transported particulate matter
southward, lower wind speeds in the Bakersfield area facilitated the
settling of the particulates at the monitoring station.
Comment 45: Earthjustice states that while the readings from
October 25, 2006 were relatively high, they were probably not beyond
the normal historical fluctuations experienced in the Valley in late
October. Earthjustice also states that fall is when the Valley's PM-10
concentrations are at their highest and also the peak season for many
dusty crops in the Valley.
Response 45: See our responses to comment 7 and 12 above.
Comment 46: Earthjustice states that EPA's ``but for'' analysis for
the October 25, 2006 event is based entirely on speculation and
conjecture and that EPA cannot say for sure what activities were taking
place in the areas of Corcoran or Bakersfield and cannot say for sure
that without the alleged high winds in Lemoore the monitors in Corcoran
and Bakersfield would not have exceeded the standard.
Response 46: See responses to comments 6 and 7 and EPA's ``but
for'' analysis in our proposed rule at 72 FR 49056-49057. EPA's
conclusion is not based on speculation and conjecture but rather on the
weight of evidence presented.
Comment 47: Earthjustice states that since the HYSPLIT analyses
provided both by the District and by meteorologist Jan Null contradict
the claim that the winds from Lemoore had a sufficient speed or
trajectory to impact Corcoran and Bakersfield, and because the Corcoran
and Bakersfield monitors were already measuring exceedances of the PM-
10 standard before the winds from Lemoore could have arrived, EPA
cannot conclude that the District has established that ``but for'' the
winds in Lemoore, the exceedances would not have occurred.
Response 47: See responses to comments 10, 11, 21, 43 and 44.
B. Other Comments
Comment 48: A commenter notes that the concept of exceptional
events for air quality purposes is ``a bad idea'' because they provide
a loophole to gut the intent of the original regulation. The commenter
expresses concern that discarding data related to exceptional events
would substantially weaken the regulation designed to protect the
health of residents in an area. In the particular instance of the SJV,
the commenter notes that the exceptional events were high winds and
construction activity. According to the commenter, these events should
not be used to justify poor air quality because high winds are a
natural occurrence and construction activity occurs repeatedly. The
commenter expresses concern that exceptional events not be used as
``additional excuses to rationalize bad air on certain days.''
Response 48: Congress amended section 319 of the CAA and required
EPA to establish regulations governing the review and handling of air
quality monitoring data influenced by exceptional events. In amending
section 319, Congress indicated that states should not have to prepare
and implement regulatory strategies designed to remedy poor air quality
when their air quality is affected by events beyond their reasonable
control. To accomplish this goal, Section 319, as amended, defined an
exceptional event and required EPA to set certain minimum substantive
and procedural requirements before data could be excluded as due to an
exceptional event. In response, as described below, EPA proposed
regulations for exceptional events in March 2006 and sought public
comments on its proposal. See 71 FR 12592 (March, 10, 2006). In March
2007, after considering all comments received, EPA published its final
rule on exceptional events which became effective on May 21, 2007. 72
FR 13560. During the exceptional events rulemaking process, EPA took
comments on the definition of exceptional events, the substantive and
procedural requirements for an event to qualify as an exceptional event
and appropriate mitigation measures in these circumstances. In this
rulemaking on air quality in the SJV, EPA is neither seeking nor
considering comments on the concept of exceptional events, which
activities would constitute exceptional events, and/or whether air
quality data may be excluded due to such events. EPA has already
addressed these issues in its EER. Comments about the concept of
exceptional events and whether such events should be considered in air
quality determinations have been decided in the exceptional events
rulemaking process and thus are outside the scope of this rulemaking.
The commenter also notes that as a general matter high winds should
not be considered an exceptional event because they are natural
occurrences. EPA has discussed high wind events extensively in the
preambles to both the proposed and the final rules on exceptional
events. The EER indicates the circumstances under which high winds can
qualify for treatment as exceptional events. Again, these general
issues were decided in the EER and EPA did not reopen comment on that
general issue in this SJV rulemaking. The commenter does not provide
data relevant to whether the high winds in this instance meet the
provisions of the EER, the issue under consideration in this rulemaking
action.
The commenter asserts that ``construction is always occurring'' and
therefore data related to these events should not be excluded. Not all
construction activity qualifies as an exceptional event. A construction
activity, like other exceptional events must meet the definitional,
substantive and procedural requirements specified in the EER. For
example, for any construction activity to be considered an exceptional
event, it must meet the definition of an exceptional event, including
for anthropogenic events such as construction, that it is an event that
is unlikely to recur at that location. Thus, by definition,
construction activity that is ``always occurring'' at a particular
location is not an exceptional event under the rule.
Comment 49: The commenter states that he is unfamiliar with details
of the SJV case but wishes to comment on the concept of exceptional
events and expressed his view that such events should not be considered
in air quality determinations. The commenter believes that there are a
wide variety of loopholes such as permitting rounding down of numbers,
exclusion of three worst days and using three year
[[Page 14712]]
averages for final attainment which ``degrade the rigor of the
standard.'' According to the commenter, excluding air quality data
affected by exceptional events further softens the initial regulation.
In the SJV case, the commenter questions why the construction activity
was not limited to periods when the atmosphere could ``handle the
load.'' In addition, the commenter discusses the construction of an
asphalt plant in a local community and notes that during the
construction of such a plant, officials sought to exclude data on
certain days because they attributed the poor air quality to interstate
transport. The commenter also refers to the treatment of fires in his
area.
Response 49: With respect to that portion of the comment concerning
the concept of exceptional events, see response to comment 48. In
response to the commenter's question about why the construction
activity was not limited to periods when the atmosphere could handle
the load, EPA notes that air quality ``load'' is not an issue for the
SRR area where construction contributed to the exceptional event. There
have been no exceedances or air quality issues in the SRR area either
before or after the construction activity. As explained in the proposed
rule, the monitor in the SRR was affected by the construction activity
because it was in such close proximity to the construction activity
(25-100 feet). 72 FR at 49062. The monitor has not recorded any
exceedances since the construction activity at the parking lot was
completed. The comments on the construction of the asphalt plant and
the fires do not relate to issues in the SJV area and thus are outside
the scope of this rulemaking.
C. List of EPA Figures in Docket
Figure 1. ``Forward Trajectories at 10, 100, & 250 meters,
Lemoore Area to Corcoran, September 22, 2006, 6 a.m. to 8 a.m. PST,''
March 6, 2008.
Figure 2. ``Forward Trajectories at 250 meters, Lemoore to
Corcoran and Bakersfield, September 22, 2006, 6 a.m. to 1 p.m. PST,''
March 6, 2008.
Figure 3. ``Forward Trajectories at 10, 100, & 250 meters,
Lemoore Area to Bakersfield, September 22, 2006, 6 a.m. to 1 p.m.
PST,'' March 6, 2008.
Figure 4. ``Forward Trajectories at 10, 100, & 250 meters,
Lemoore Area to Corcoran, October 25, 2006, 5 a.m. to 7 a.m. PST,''
March 6, 2008.
Figure 5. ``Forward Trajectories at 250 meters, Lemoore to
Corcoran to Bakersfield, October 25, 2006, 5 a.m. to 11 a.m. PST,''
March 6, 2008.
Figure 6. ``Forward Trajectories at 10, 100, & 250 meters,
Lemoore Area to Bakersfield, October 25, 2006, 5 a.m. to 11 a.m. PST,''
March 6, 2008.
Figure 7. ``Annual Peak Day PM10 Concentrations at
Corcoran,'' March 6, 2008.
Figure 8. ``Annual Peak Day PM10 Concentrations at
Bakersfield,'' March 6, 2008.
Figure 9. ``Annual Peak Day PM10 Concentrations at
Oildale,'' March 6, 2008.
Figure 10. ``Annual Peak Fall Day PM10 Concentrations at
Corcoran (September, October, November Data Only),'' March 6, 2008.
Figure 11. ``Annual Peak Fall Day PM10 Concentrations at
Bakersfield (September, October, November Data Only),'' March 6, 2008.
Figure 12. ``Annual Peak Fall Day PM10 Concentrations at
Oildale (September, October, November Data Only),'' March 6, 2008.
III. Final Action
For the reasons set forth in detail in EPA's proposed rule and in
today's final rule, including the responses to comments, EPA is
concurring with the State's and the Santa Rosa Rancheria Tribe's
requests to flag exceedances occurring in 2006 as being caused by
exceptional events. (i.e., high winds and construction activity in very
close proximity to the monitor, respectively). In addition, as set
forth in its proposed rule, EPA is finding that the monitor at the
Santa Rosa Rancheria was not properly sited for purposes of collecting
data for comparison to the NAAQS during the period that exceedances
were monitored in 2006. EPA is thus concluding that the exceedances
that are the subject of these requests should be excluded from use in
determining whether the SJV has attained the PM-10 NAAQS. EPA is
finalizing its proposal to affirm the determination of attainment for
the SJV, based on quality-assured data through December, 2006.\34\
---------------------------------------------------------------------------
\34\ The District has flagged exceedances occurring on July 4,
2007 and January 4, 2008 as being caused by exceptional events. We
intend to address these exceedances in the future.
---------------------------------------------------------------------------
For the reasons set forth in its proposed rule and in this final
rule, EPA is denying the December 29, 2006 petition for reconsideration
and the March 21, 2007 petition for withdrawal of EPA's 2006
determination of attainment filed by Earthjustice on behalf of the
Sierra Club, Latino Issues Forum, and others.
IV. Statutory and Executive Order Reviews
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is not a ``significant regulatory action'' and therefore is not
subject to review by the Office of Management and Budget. For this
reason, this action is also not subject to Executive Order 13211,
``Actions Concerning Regulations That Significantly Affect Energy
Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This action
merely makes a determination based on air quality data, and imposes no
additional requirements. Accordingly, the Administrator certifies that
this 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 does not impose any additional
enforceable duty, 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).
Executive Order 13175 (65 FR 67249, November 9, 2000) requires EPA
to develop an accountable process to ensure ``meaningful and timely
input by tribal officials in the development of regulatory policies
that have tribal implications.'' As discussed in our proposed rule,
several Indian tribes have reservations located within the boundaries
of the SJV. EPA is aware of only one tribe in the SJV that operates a
PM-10 monitor, the Santa Rosa Rancheria. Prior to and since the
proposed rule, EPA has consulted with representatives of the Santa Rosa
Rancheria Tribe on the data recorded by its monitor, and the flagging
of the data, and will continue to work with the Tribe, as provided for
in Executive Order 13175. Accordingly, EPA has addressed Executive
Order 13175 to the extent that it applies to this action. This action
also does not have Federalism implications because it does 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). This
action merely makes a determination based on air quality data and does
not alter the relationship or the distribution of power and
responsibilities established in the Clean Air Act. Executive Order
12898 establishes a Federal policy for incorporating environmental
justice into Federal agency actions by directing agencies to identify
and address, as
[[Page 14713]]
appropriate, disproportionately high and adverse human health or
environmental effects of their programs, policies, and activities on
minority and low-income populations. Today's action involves
determinations based on air quality considerations and affirms that the
SJV attained the PM-10 NAAQS. It will not have disproportionately high
and adverse effects on any communities in the area, including minority
and low-income communities.
This rule also is not subject to Executive Order 13045 ``Protection
of Children from Environmental Health Risks and Safety Risks'' (62 FR
19885, April 23, 1997), because it is not economically significant. The
requirements of section 12(d) of the National Technology Transfer and
Advancement Act of 1995 (15 U.S.C. 272 note) do not apply because it
would be inconsistent with applicable law for EPA, when determining the
attainment status of an area, to use voluntary consensus standards in
place of promulgated air quality standards and monitoring procedures
that otherwise satisfy the provisions of the Clean Air. This 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.).
The Congressional Review Act, 5 U.S.C. section 801 et seq., as
added by the Small Business Regulatory Enforcement Fairness Act of
1996, generally provides that before a rule may take effect, the agency
promulgating the rule must submit a rule report, which includes a copy
of the rule, to each House of the Congress and to the Comptroller
General of the United States. EPA will submit a report containing this
rule and other required information to the U.S. Senate, the U.S. House
of Representatives, and the Comptroller General of the United States
prior to publication of the rule in the Federal Register. A major rule
cannot take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
section 804(2).
Under section 307(b)(1) of the Clean Air Act, petitions for
judicial review of this action must be filed in the United States Court
of Appeals for the appropriate circuit by May 19, 2008. Filing a
petition for reconsideration by the Administrator of this final rule
does not affect the finality of this rule for the purposes of judicial
review nor does it extend the time within which a petition for judicial
review may be filed, and shall not postpone the effectiveness of such
rule or action. This action may not be challenged later in proceedings
to enforce its requirements. (See section 307(b)(2).)
List of Subjects
40 CFR Parts 52
Environmental protection, Air pollution control, Incorporation by
reference, Particulate matter, Reporting and recordkeeping
requirements.
40 CFR Part 81
Environmental protection, Air pollution control, National parks,
Wilderness areas.
Dated March 7, 2008.
Wayne Nastri,
Regional Administrator, Region 9.
[FR Doc. E8-5188 Filed 3-18-08; 8:45 am]
BILLING CODE 6560-50-P