[Federal Register Volume 67, Number 170 (Tuesday, September 3, 2002)]
[Proposed Rules]
[Pages 56249-56252]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-22362]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 81
[Docket WA-02-001; FRL-7271-9]
Finding of Attainment for PM10; Wallula
PM10 Nonattainment Area, WA
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: EPA is proposing to find that the Wallula nonattainment area
in Washington has attained the National Ambient Air Quality Standards
(NAAQS) for particulate matter with an aerodynamic diameter of less
than or equal to a nominal ten micrometers (PM10) as of
December 31, 2001. EPA's proposed finding is based on EPA's review of
monitored air quality data reported for the years 1999 through 2001.
DATES: Written comments must be received on or before October 3, 2002.
ADDRESSES: Written comments may be mailed to Donna Deneen, Office of
Air Quality, Mailcode OAQ-107, EPA Region 10, 1200 Sixth Avenue,
Seattle, Washington, 98101. Copies of documents relevant to this action
are available for public review during normal business hours (8 a.m. to
4:30 p.m.) at this same address.
FOR FURTHER INFORMATION CONTACT: Donna Deneen, Office of Air Quality,
EPA Region 10, 1200 Sixth Avenue, Seattle Washington, 98101, (206) 553-
6706.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Background
A. Designation and Classification of PM10
Nonattainment Areas
B. Attainment Determinations
II. EPA's Proposed Action
A. Monitored Air Quality Data
B. Natural Event Determinations
(1) Causal Relationship between High Winds and Exceedances
(2) BACM on Contributing Anthropogenic Sources of Windblown Dust
C. Effect of Proposed Finding of Attainment
III. Administrative Requirements
I. Background
A. Designation and Classification of PM10 Nonattainment
Areas
The Wallula area was designated nonattainment for PM10
and classified as moderate under sections 107(d)(4)(B) and 188(a) of
the Clean Air Act upon enactment of the Clean Air Act Amendments of
1990 (Act or CAA).\1\ See 40 CFR 81.348 (PM10 Initial
Nonattainment Areas); see also 56 FR 56694 (November 6, 1991). Under
subsections 188(a) and (c)(1) of the Act, all initial moderate
PM10 nonattainment areas had the same applicable attainment
date of December 31, 1994.
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\1\ The 1990 Amendments to the CAA made significant changes to
the CAA. See Public Law 101-549, 104 Stat. 2399. References herein
are to the CAA as amended in 1990. The Clean Air Act is codified, as
amended, in the United States Code at 42 U.S.C. 7401 et seq.
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States containing initial moderate PM10 nonattainment
areas were required to develop and submit to EPA by November 15, 1991,
a state implementation plan (SIP) revision providing for, among other
things, implementation of reasonably available control measures (RACM),
including reasonably available control technology (RACT), and a
demonstration of attainment of the PM10 NAAQS by December
31, 1994. See Section 189(a) of the CAA.\2\ In response to this
submission requirement, the Washington Department of Ecology (Ecology)
submitted a SIP revision for Wallula on November 15, 1991.
Subsequently, Ecology submitted additional information indicating that
nonanthropogenic sources may be significant in the Wallula
nonattainment area during windblown dust events. Based on our review of
the State's submissions, we deferred action on several elements in the
Wallula SIP, approved the control measures in the SIP as meeting RACM/
RACT, and, under section 188(f) of the CAA, granted a temporary waiver
to extend the attainment date for Wallula to December 31, 1997. See 60
FR 63109 (December 6, 1995)(proposed action); 62 FR 3800 (January 27,
1997) (final action). The temporary waiver was intended to provide
Ecology time to evaluate further the Wallula nonattainment area and to
determine the significance of the anthropogenic and nonanthropogenic
sources impacting the area. Once these activities were complete or the
temporary waiver expired, EPA was to make a decision on whether the
area was eligible for a permanent waiver under section 188(f) of the
CAA or whether the area had attained the standard by the extended
attainment date. See 62 FR at 3802.
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\2\ The moderate area SIP requirements are set forth in section
189(a) of the CAA.
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On February 9, 2001, EPA published a Federal Register notice making
a final determination that the Wallula area had not attained the
PM10 standard by the attainment date of December 31, 1997.
See 66 FR 9663 (February 9, 2001) (final action); (65 FR 69275
(November 16, 2000) (proposed action). EPA made this determination
based on air quality data for calendar years 1995, 1996, and 1997. As a
result of that finding, the Wallula PM10 nonattainment area
was reclassified by operation of law as a serious PM10
nonattainment area effective March 12, 2001 with an attainment date of
December 31, 2001.\3\ See 188(b)(2)(A) and 188(c)(2).
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\3\ Under section 188(c)(2) of the CAA, attainment areas
designated nonattainment for PM10 under section 107(d)(4)
of the CAA were required to attain the PM10 standard no
later than December 31, 2001. As discussed above, Wallula was
designated nonattainment under section 107(d)(4) of the CAA.
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B. Attainment Determinations
Pursuant to sections 179(c) of the CAA, we have the responsibility
of determining within six months of the applicable attainment date
whether, based on air quality data, PM10 nonattainment areas
attained the PM10 NAAQS by that date. Determinations under
section 179(c)(1) of the Act are to be based upon the area's ``air
quality as of the attainment date.''
Generally, we determine whether an area's air quality is meeting
the PM10 NAAQS for purposes of section 179(c)(1) based upon
data gathered at established state and local air monitoring stations
(SLAMS) and national air monitoring stations (NAMS) in the
nonattainment areas and entered into the EPA Air Quality Subsystem
(AQS). Data entered into the AQS has been determined to meet Federal
monitoring requirements (see 40 CFR 50.6, 40 CFR part 50, appendix J,
40 CFR part 53, 40 CFR part 58, appendix A & B) and may be used to
determine the attainment status of areas. We also
[[Page 56250]]
consider air quality data from other air monitoring stations in the
nonattainment area provided that the stations meet the Federal
monitoring requirements for SLAMS. All data are reviewed to determine
the area's air quality status in accordance with our guidance at 40 CFR
part 50, appendix K.
Attainment of the annual PM10 standard is achieved when
the annual arithmetic mean PM10 concentration over a three-
year period (for example 1999, 2000, and 2001 for areas with a December
31, 2001 attainment date) is equal to or less than 50 micrograms per
cubic meter ([mu]g/m3). Attainment of the 24-hour standard
is determined by calculating the expected number of days in a year with
PM10 concentrations greater than 150 [mu]g/m3.
The 24-hour standard is attained when the expected number of days with
levels above 150 [mu]g/m3 (averaged over a three-year
period) is less than or equal to one. Three consecutive years of air
quality data are generally required to show attainment of the annual
and 24-hour standards for PM10. See 40 CFR part 50 and
appendix K.
II. EPA's Proposed Action
A. Monitored Air Quality Data
Ecology established and operates one PM10 SLAMS
monitoring sites in the Wallula PM10 nonattainment area. The
Wallula monitor meets EPA SLAMS network design and siting requirements,
set forth at 40 CFR part 58, appendices D and E, and has been
monitoring for PM10 since before1990. Because the Wallula
monitor is scheduled to sample only once every six days, each measured
exceedance is generally counted as six expected exceedances and would
generally represent a violation of the 24-hour PM10
standard.
The air quality data in AQS for this monitor shows that, for the
three-year period from 1999 though 2001, there were no violations of
the annual PM10 standard. The annual PM10 NAAQS
is 50 [mu]g/m3. The annual average concentration for 1999,
2000, and 2001 were 34 [mu]g/m3, 29 [mu]g/m3, and
29 [mu]g/m3, respectively. Based on this information, EPA
has determined that the area attained the annual PM10
standard as of the extended attainment date of December 31, 2001.
With respect to the 24-hour PM10 standard, a review of
the air quality data in AQS for the three-year period from 1999 through
2001 shows that there were two recorded exceedence of the 24-hour
PM10 standard recorded at the Wallula monitor: A
concentration of 297 [mu]g/m3 on June 23, 1999, and a
concentration of 215 [mu]g/m3 on August 10, 2000. The State
has flagged both of these exceedances as attributable to high wind
``natural events.'' The next highest 24-hour PM10
concentrations measured during this time period were 126 [mu]g/
m3 on June 29, 1999 and 109 [mu]g/m3 on July 12,
2001. Other than those, no other concentrations above 100 [mu]g/
m3 were measured at the monitor during the rest of the 3-
year period. These data suggest that the 24-hour average
PM10 concentration in the Wallula area is generally well
below the standard, but for ``natural events.''
B. Natural Event Determinations
Wallula, Washington is located in eastern Washington on the
Columbia Plateau. The Columbia Plateau is known for its prolonged
periods of strong winds which carry dust particulates for hundreds of
miles downwind. Wind erosion is a particular problem on the Plateau
because of the natural dustiness of the region due to its dry
environments, scant vegetation, unpredictable high winds, and soils
which contain substantial quantities of PM10 size and
smaller particulate matter. See ``Farming with the Wind: Best
Management Practices for Controlling Wind Erosion and Air Quality on
Columbia Plateau Croplands,'' (1998).
Under section 107(d)(4)(B)(ii) of the CAA and 40 CFR part 50,
appendix K, section 2.4, specific exceedances due to uncontrollable
natural events, such as unusually high winds, may be discounted or
excluded entirely from decisions regarding an area's air quality status
in appropriate circumstances. See Memorandum from EPA's Assistant
Administrator for Air and Radiation to EPA Regional Air Directors
entitled ``Areas Affected by Natural Events,'' dated May 30, 1996
(EPA's Natural Events Policy). EPA has stated that it will treat
ambient PM10 exceedances caused by dust raised by unusually
high winds as due to uncontrollable natural events (and thus excludable
from attainment determinations) if either (1) the dust originated from
nonanthropogenic sources or (2) the dust originated from anthropogenic
sources controlled with best available control measures (BACM). See
Natural Events Policy, pp. 4-5. This approach recognizes that while
exceedances of the PM10 standard during unusually high winds
may not be entirely preventable, there still are measures that can be
taken to help protect public health. EPA's Natural Events Policy sets
forth a process for declaring an exceedance as due to natural events
and for documenting a natural events claim. Where a State believes
natural events have caused a violation of the NAAQS, the State enters
the exceedance in the EPA data base, flags the exceedance as being
attributable to a natural event, documents a clear causal relationship
between the measured exceedance and the natural event, and develops a
natural events action plan (NEAP) that is tailored to the
PM10 sources and the circumstances which caused the
exceedance. The NEAP should include commitments to: (1) Establish
public education and notification programs; (2) minimize public
exposure to high concentrations of PM10 due to future
natural events; (3) abate or minimize contributing controllable sources
of PM10 which includes the application of ``best available
control measures'' (BACM) to any sources of soil that have been
disturbed by anthropogenic activities; (4) identify, study, and
implement practical mitigating measures as necessary; and (5)
periodically reevaluate the NEAP. See Natural Events Policy, pp. 5-8.
In the case of high-wind events where the sources of dust are
anthropogenic, the State should also document that BACM were required
for those sources and that sources were in compliance with BACM at the
time of the high-wind event. If BACM are not required for some dust
sources, the NEAP must include agreements with appropriate stakeholders
to minimize future emissions from such sources using BACM.
As discussed above, Ecology flagged the June 23, 1999 and the
August 10, 2000, exceedences in the AQS data base as exceedences caused
by high winds under EPA's Natural Events Policy. Ecology has also
flagged exceedances that occurred on June 21, 1997 and July 10, 1998 as
natural events. As discussed in more detail below and in the technical
support document, EPA concludes that the June 21, 1997, July 10, 1998,
June 23, 1999, and August 10, 2000, exceedances qualify as high wind
natural events under EPA's Natural Events Policy. Therefore, EPA
proposes to exclude the 1999 and 2000 exceedences from consideration in
determining whether the Wallula PM10 nonattainment area
attained the 24-hour as of December 31, 2001. As a result, the expected
number of days over the 24-hour standard for 1999, 2000, and 2001 is
0.0 and, when averaged over the three-year period from 1999 through
2001, the three-year expected exceedence rate is also 0.0. EPA
therefore believes that the Wallula PM10 nonattainment area
attained the 24-hour PM10 standard as of the serious area
attainment date of December 31, 2001.
[[Page 56251]]
(1) Causal Relationship Between High Winds and Exceedances
EPA's Natural Events Policy provides that ``the State is
responsible for establishing a clear causal relationship between the
measured exceedance and the natural event.'' Natural Events Policy, p.
8. Ecology provided meteorological data to support its position that
the exceedances measured at the Wallula monitor on June 21, 1997, July
10, 1998, June 23, 1999, and August 10, 2000 were due to high wind
natural events. These data show that the highest average hourly values
on three of the four days, June 21, 1997, June 10, 1998, and August 10,
2000, reached 31 mph, 27 mph, and 38 mph, respectively. These
windspeeds were greater than 23 mph, which is the windspeed level
Ecology uses generally to evaluate whether conditions are sufficient to
produce significant concentrations of airborne dust. See, e.g.,
Documentation of Natural Event Due to High Winds, August 10, 2000,
Wallula, Washington, page 3. Based on these recorded windspeeds, along
with additional information documenting the lack of precipitation
preceding those days, newspaper articles documenting severe dust storms
resulting from the high winds, and additional information regarding
wind direction and sources in the area, Ecology has shown a clear
causal relationship between the high winds and the high PM10
values for those days. See Ecology's Natural Event submissions for June
21, 1997, June 10, 1998, and August 10, 2000.
On June 23, 1999, the highest average hourly windspeed and average
daily windspeed of 15 mph and 10 mph, respectively, were lower than for
the other three days. Since these lower windspeeds, on their own, did
not explain the high levels of PM10 measured at the monitor,
Ecology conducted an investigation to determine what other activities
or sources may have led to the exceedance. First, Ecology investigated
whether local sources, such as the nearby pulp mill (primarily a
combustion source) or feed lot, may have contributed to the exceedence.
Based on meteorological data showing that the winds came from the
direction of the pulp mill and the feed lot for only a short period of
time, Ecology determined that these local sources could have been only
insignificant contributors to the 24-hour concentration on June 23,
1999. Second, Ecology also evaluated the results of filter analysis for
June 23, 1999. This analysis showed that the particulate on the filter
was primarily crustal material, rather than combustion material. The
presence of crustal material on the filter is consistent with what
would be expected to be found as a result of a high wind event.
With the feedlot and pulp mill ruled out as the primary
contributors to the exceedance on June 23, 1999, and no other local
sources known to potentially have a large impact on the monitor,
Ecology looked more closely at the regional meteorology and/or other
unique conditions that could account for the high concentrations at the
monitor. This investigation revealed that high average hourly
windspeeds (more than 20 mph) had, in fact, been recorded at several
meteorological stations in Eastern Washington on the evening of June
22, 1999 (i.e., at Pasco, Ephrata, Moses Lake, Hanford, and Pendleton).
In addition, weather data from Washington State University showed that
in many areas in the region, no precipitation had been measured for as
many as 36 days prior to June 23, 1999, making area soils vulnerable to
entrainment by high winds. Ecology also considered in its investigation
the unusually high concentration at the monitor (consistent with a high
wind event), the possibility of elevated winds channeling through
nearby Wallula Gap (but then dissipating at the monitor), and filter
analysis showing wind blown dust on the filter. Ecology concluded that,
although it was impossible to discern the exact high wind event that
caused the June 23, 1999, exceedance, meteorological and other
conditions clearly supported the occurrence of such a natural event and
that it was therefore reasonable to attribute the June 23, 1999
exceedance as due to a high wind natural event.
Based on the information provided by Ecology, EPA agrees with
Ecology that it is reasonable to treat the June 23, 1999, exceedance as
due to a natural event. Note that consideration of this event as due to
high winds does not eliminate the need for efforts to reduce the
emissions of windblown dust to the extent practicable. This issue is
discussed in more detail below.
(2) BACM on Contributing Anthropogenic Sources of Windblown Dust
EPA's Natural Events Policy states that PM10 exceedances
``due to dust raised by unusually high winds will be treated as due to
uncontrollable natural events under the following conditions: (1) The
dust originated from anthropogenic sources, or (2) the dust originated
from anthropogenic sources controlled with BACM. ``The BACM must be
implemented at contributing anthropogenic sources of dust in order for
PM10 NAAQS exceedances to be treated as due to
uncontrollable natural events under this policy.'' Natural Events
Policy, pp. 4-5. The Natural Events Policy further states that the
Natural Events Action Plan developed by the State should include
commitments to ``abate or minimize appropriate contributing
controllable sources of PM10.'' In the case of high winds,
such a program should include ``application of BACM to any sources of
soil that have been disturbed by anthropogenic activities.'' Natural
Events Policy, p. 6. If BACM are not defined for the anthropogenic
sources at the time the NEAP is developed, the NEAP should identify,
study and implement practical mitigating measures as necessary. Natural
Events Policy, p. 7.
In response to EPA's May 1996 Natural Events Policy, Ecology
prepared and submitted a Natural Events Action Plan for the Columbia
Plateau to EPA in March 1998 (Columbia Plateau NEAP), which includes
the Wallula nonattainment area. Ecology also provided information
following up on the Columbia Plateau NEAP in 1999 and March 2001. The
Columbia Plateau NEAP identifies dust from upwind agricultural fields
as the chief source of high levels of PM10 in the Columbia
Plateau. In the NEAP, Ecology described BACM for agricultural lands as
being equivalent to Best Management Practices (BMPs) and explained that
BMPs are measures that offer the greatest level of control given
available technology and economic considerations. Columbia Plateau
NEAP, pg. 12. BMPs for agricultural lands in the Columbia Plateau have
been identified in ``Farming with the Wind: Best Management Practices
for Controlling Wind Erosion and Air Quality on Columbia Plateau
Croplands,'' (1998), a publication that has been widely distributed to
farmers in the Columbia Plateau.
Data collected by the Natural Resources Conservation Service (NRCS)
provides information on the extent of the use of BMPs in Benton and
Walla Walla Counties at the time of the exceedances. The data show that
the overall trend of tillage BMPs \4\ in Benton and Walla Walla
Counties is upward, with more than 50% of planted land using tillage
BMPs in Benton County and with more than 77% of planted land using
tillage BMPs in Walla Walla County, the county in which the
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majority of the nonattainment area is located.
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\4\ ``Tillage'' BMPs includes conservation tillage and
conventional tillage with 15-30 percent residue.
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The data also show an increase in the amount of acreage in Benton
County and Walla Walla County that has been put in the USDA
Conservation Reserve Program (CRP). The CRP is particularly effective
in reducing dust emissions because permanent vegetative cover on those
lands reduces the opportunity for erosion to occur. In both counties,
the CRP acreage percentage increased substantially from 1994 to 2000.
In Benton County, CRP acreage increased by over 100 percent, while in
Walla Walla County, CRP acreage increased by almost 40 percent. This
increase is another indication of the widespread use and the overall
upward trend in the use of BMPs in the Wallula area. In sum, data show
that of total planted and CRP acreage, 63 percent in Benton County and
84 percent in Walla Walla County used tillage BMPs or was placed in the
CRP in 2000.
Based on the information provided by Ecology, other available
information showing widespread use of, and an overall upward trend in,
the use of BMPs in the Wallula area from 1994 to 2000, and the area's
soil and climate characteristics, EPA concludes that BACM was being
implemented at the time of the June 21, 1997, July 10, 1998, June 23,
1999, and August 10, 2000 exceedances. EPA, therefore, believes that
these exceedences should be excluded from consideration in attainment
determinations for the Wallula PM10 nonattainment area and
that, in the absence of any other exceedances during 1999, 2000, and
2001, the Wallula PM10 nonattainment area attained the 24-
hour PM10 standard as of the serious area attainment date of
December 31, 2001. EPA notes, however, that identification and
application of BACM for agricultural lands is evolving. EPA expects
Ecology to continue efforts in identifying and implementing BACM on
sources of agricultural windblown dust in the Wallula area in order for
future exceedances caused by high winds to be characterized as
``natural events'' and excluded in attainment determinations. This
includes reviewing and revising the Columbia Plateau NEAP on a periodic
basis to ensure continued implementation of BACM on sources of wind
blown dust in the area.
C. Effect of Proposed Finding of Attainment
As discussed above, EPA proposes to find that the Wallula
PM10 nonattainment area attained the PM10 NAAQS
as of the serious area attainment date of December 31, 2001. If we
finalize this proposal, consistent with CAA section 188, the area will
remain a serious PM10 nonattainment area, but will avoid the
additional planning requirements that apply to serious PM10
nonattainment areas that fail to meet the attainment date under section
189(d) of the CAA.
This proposed finding of attainment should not be confused with a
redesignation to attainment under CAA section 107(d). Washington has
not submitted a serious area plan for the Wallula area that meets the
requirements of section 189(b) of the CAA. In addition, Washington has
not submitted a maintenance plan as required under section 175(A) of
the CAA or met the other CAA requirements for redesignations to
attainment. The designation status in 40 CFR part 81 will remain
serious nonattainment for the Wallula PM10 nonattainment
area until such time as Washington meets the CAA requirements for
redesignations to attainment.
We are soliciting public comments on EPA's proposal to find that
the Wallula PM10 nonattainment area has attained the
PM10 NAAQS as of the December 31, 2001, attainment date.
These comments will be considered before taking final action.
Interested parties may participate in the Federal rulemaking process by
submitting written comments to the EPA Regional office listed in the
ADDRESSES section of this document.
III. Administrative Requirements
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
proposed action is not a ``significant regulatory action'' and
therefore is not subject to review by the Office of Management and
Budget. 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
proposed action merely makes a determination based on air quality data
and does not impose any requirements. Accordingly, the Administrator
certifies that this proposed finding 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
proposed finding does not impose any 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).
This proposed finding also does not have tribal implications
because it will not have a substantial direct effect on one or more
Indian tribes, on the relationship between the Federal Government and
Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes, as specified by
Executive Order 13175 (65 FR 67249, November 9, 2000). 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
proposed 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. This proposed
finding 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 this proposed action does not involve technical standards. This
proposed finding does not impose an information collection burden under
the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501
et seq.).
List of Subjects in 40 CFR Part 81
Environmental protection, Air pollution control, National parks,
Wilderness areas.
Dated: August 23, 2002.
John Iani,
Regional Administrator, Region 10.
[FR Doc. 02-22362 Filed 8-30-02; 8:45 am]
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