[Federal Register Volume 75, Number 235 (Wednesday, December 8, 2010)]
[Proposed Rules]
[Pages 76336-76337]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-30849]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 58
[EPA-HQ-OAR-2006-0735; FRL-9236-4]
Notice of Data Availability Regarding Two Studies of Ambient Lead
Concentrations Near a General Aviation Airport
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of Data Availability (NODA).
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SUMMARY: The EPA issued a final rule on November 12, 2008, (effective
date January 12, 2009) that revised the primary and secondary National
Ambient Air Quality Standards (NAAQS) for lead and associated
monitoring requirements. On December 30, 2009, EPA proposed revisions
to the lead monitoring requirements. As part of the proposed revisions,
EPA proposed requiring monitoring near general aviation airports
estimated to have lead emissions of 0.50 tons per year or greater.
After the proposal was published, EPA completed a study of ambient lead
concentrations near a general aviation airport which may be referenced
by the EPA in preparing the final lead monitoring requirements. In
addition, a final report on one of the studies relied on in the
proposed rule has become available. This action announces the
availability of these two studies in the Revision to Lead Ambient Air
Monitoring Requirements docket (EPA-HQ-OAR-2006-0735).
FOR FURTHER INFORMATION CONTACT: For questions regarding the additional
data, contact Kevin Cavender, Air Quality Assessment Division, C304-06,
Environmental Protection Agency, U.S. EPA (C304-06), AQAD/AAMG,
Research Triangle Park, NC 27711; telephone number: 919-541-2364; fax
number: 919-541-1903; e-mail address: [email protected].
SUPPLEMENTARY INFORMATION:
I. What is today's action?
This action announces the availability of two studies that contain
information on ambient lead concentrations near an airport that has
lead emissions from the combustion of leaded aviation fuel. The first
is a local-scale airport modeling and monitoring study conducted by the
EPA to investigate near-source ambient lead concentrations attributable
to lead from the combustion of leaded aviation gasoline (EPA, 2010).
The second is a final report documenting the study relied on in the
proposed rule which was used to identify airports as having
[[Page 76337]]
the potential to exceed the lead NAAQS (South Coast Air Quality
Management District, 2010). Both studies are located in Docket ID No.
EPA-HQ-OAR-2006-0735.
II. How does this information relate to the Proposed Rule--revisions to
lead ambient air monitoring requirements?
These two studies provide information on the potential for lead
emissions from the combustion of leaded aviation fuel at airports to
exceed the lead NAAQS as well as other information (locations of
maximum emissions and lead concentration gradients) that may be
referenced in the final rule.
The first study developed and evaluated an air quality modeling
approach that could be used to evaluate local-scale concentrations of
lead in the vicinity of an airport where piston-engine aircraft are
operated. The study also included an assessment of the maximum 3-month
average lead concentration and model sensitivity tests. The maximum 3-
month average lead concentration was evaluated in order to compare the
model output with the NAAQS for lead, 0.15 [mu]g/m3, reported as the
maximum 3-month average concentration.
Air monitoring was conducted to evaluate the performance of the air
modeling approach, to assist in the quantification of the contribution
of lead from general aviation emissions to local air quality, and to
provide information about the change in lead concentrations with
distance from the airport. Air quality modeling was conducted using
EPA's American Meteorological Society/Environmental Protection Agency
Regulatory Model or AERMOD. Inputs to the model included a
comprehensive lead emission inventory incorporating on-site, time-in-
mode and sub-daily activity data for piston engine aircraft. Model
inputs also included considerations of aircraft-induced wake
turbulence, plume rise of the aircraft exhaust, and allocation of
approach and climb-out emissions to 50 meter increments in altitude.
To evaluate the modeling approach used here, ambient lead
concentrations were measured upwind and downwind of the Santa Monica
Airport and compared to modeled air concentrations. Modeling results
paired in both time and space with monitoring data showed excellent
overall agreement. Modeling results show aircraft engine run-up is the
most important source contribution to the maximum lead concentration.
Sensitivity analysis shows that engine run-up time, lead concentration
in aviation gasoline, and the fraction of piston engine aircraft that
are twin engine are the most important parameters in determining near-
field lead concentrations. Year-long air quality modeling for 2008 and
sensitivity analysis for the maximum 3-month average concentration
period suggest the potential for 3-month average lead concentrations
that exceed the current NAAQS for lead (0.15 [mu]g/m\3\) and help
inform the process for identifying locations of maximum concentration.
The second study is the final report on one of the airport studies
referenced in the proposed rule. This report provides additional
information on the approach, methods, and results of the study.
III. How can I get a copy of these documents and other related
information?
1. Docket. EPA has established a docket for this action under
Docket ID No. EPA-HQ-OAR-2006-0735. All documents in the docket are
listed on the http://www.regulations.gov Web site. Although listed in
the index, some information is not publicly available, e.g.,
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Certain other material, such as
copyrighted material, is not placed on the Internet and will be
publicly available only in hard copy form. Publicly available docket
materials are available either electronically through http://www.regulations.gov or in hard copy at the Revisions to Lead Ambient
Air Monitoring Requirements docket, Docket ID No. EPA-OAR-2006-0735,
EPA Docket Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave.,
NW., Washington, DC. This Docket Facility is open from 8:30 a.m. to
4:30 p.m. Monday through Friday excluding legal holidays. The docket
telephone number is (202) 566-1742. The Public Reading Room is open
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal
holidays. The telephone number for the Public Reading Room is (202)
566-1744.
2. Electronic Access. You may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr/.
IV. References
U.S. EPA (2010) Development and evaluation of an air quality
modeling approach for lead emissions from piston-engine aircraft
operating on leaded aviation gasoline. EPA-420-R-10-007. Available
at http://www.epa.gov/otaq/aviation.htm.
South Coast Air Quality Management District (2010) General
Aviation Airport Air Monitoring Study Final Report. Final Report.
List of Subjects in 40 CFR Part 58
Ambient air monitoring, Air pollution control, Environmental
protection, Intergovernmental relations, Reporting and recordkeeping
requirements.
Dated: December 2, 2010.
Mary E. Henigin,
Acting Director, Office of Air Quality Planning and Standards.
[FR Doc. 2010-30849 Filed 12-7-10; 8:45 am]
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