

[Federal Register: November 16, 2007 (Volume 72, Number 221)]
[Proposed Rules]               
[Page 64570-64573]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16no07-20]                         

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 87

[EPA-HQ-OAR-2007-0294; FRL-8495-4]

 
Petition Requesting Rulemaking To Limit Lead Emissions from 
General Aviation Aircraft; Request for Comments

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of petition for rulemaking.

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SUMMARY: Friends of the Earth has filed a petition with EPA, requesting 
that EPA find pursuant to section 231 of the Clean Air Act that lead 
emissions from general aviation aircraft cause or contribute to air 
pollution that may reasonably be anticipated to endanger public health 
or welfare and that EPA propose emissions standards for lead from 
general aviation aircraft. Alternatively, Friends of the Earth requests 
that EPA commence a study and investigation of the health and 
environmental impacts of lead emissions from general aviation aircraft, 
if EPA believes that insufficient information exists to make such a 
finding. The petition submitted by Friends of the Earth explains their 
view that lead emissions from general aviation aircraft endanger the 
public health and welfare, creating a duty for the EPA to propose 
emission standards. EPA invites information and comments from all 
interested parties on the issues raised by this petition.

DATES: Comments must be received on or before March 17, 2008.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2007-0294, by one of the following methods:
     http://www.regulations.gov: Follow the on-line instructions for 

submitting comments.
     Email: a-and-r-docket@epa.gov, Attention Docket ID No. 
OAR-2007-0294.
     Fax: (202) 566-9744
     Mail. Send your comments to: Air and Radiation Docket, 
Environmental Protection Agency, Mailcode: 6102T, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460, Attention: Docket ID No. OAR-2007-
0294.
     Hand Delivery. Deliver your comments to: Air and Radiation 
Docket in the EPA Docket Center, (EPA/DC) EPA West, Room 3334, 1301 
Constitution Ave., NW., Washington, DC, Attention: Docket ID No. OAR-
2007-0294. Such deliveries are only accepted during the Docket's normal 
hours of operation, and special arrangements should be made for 
deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2007-0294. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information provided, 

unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through http://www.regulations.gov. The 

http://www.regulations.gov website is an ``anonymous access'' system, which 

means EPA will not know your identity or contact information unless you 
provide it in the body of your comment. If you send an e-mail comment 
directly to EPA without going through http://www.regulations.gov your e-mail 

address will be automatically captured and included as part of the 
comment that is placed in the public docket and made available on the 
Internet. If you submit an electronic comment, EPA recommends that you 
include your name and other contact information in the body of your 
comment and with any disk or CD-ROM you submit. If EPA cannot read your 
comment due to technical difficulties and cannot contact you for 
clarification, EPA may not be able to consider your comment. Electronic 
files should avoid the use of special characters, any form of 
encryption, and be free of any defects or viruses. For additional 
information about EPA's public docket visit the EPA Docket Center 
homepage at http://www.epa.gov/epahome/dockets.htm.

    Docket: All documents in the docket are listed in the 
http://www.regulations.gov index. Although listed in the index, some 

information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the Air and Radiation Docket 

in the EPA Docket Center, (EPA/DC) EPA West, Room 3334, 1301 
Constitution Ave., NW., Washington, DC, Docket ID No. OAR-2007-0294. 
This docket 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, and the telephone number for the Air and 
Radiation Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Bryan Manning, Assessment and 
Standards Division, Office of Transportation and Air Quality, 2000 
Traverwood Drive, Ann Arbor, MI 48105; telephone number: 734-214-4832; 
fax number: 734-214-4816; e-mail address: manning.bryan@epa.gov, 
Assessment and Standards Division Hotline; telephone number: (734) 214-
4636; e-mail address: asdinfo@epa.gov.

SUPPLEMENTARY INFORMATION: 

I. General Information

A. What Should I Consider as I Prepare My Comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
http://www.regulations.gov or e-mail. Clearly


[[Page 64571]]

mark the part or all of the information that you claim to be CBI. For 
CBI information in a disk or CD-ROM that you mail to EPA, mark the 
outside of the disk or CD-ROM as CBI and then identify electronically 
within the disk or CD-ROM the specific information that is claimed as 
CBI). In addition to one complete version of the comment that includes 
information claimed as CBI, a copy of the comment that does not contain 
the information claimed as CBI must be submitted for inclusion in the 
public docket. Information so marked will not be disclosed except in 
accordance with procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the appropriate docket identification number in 
the subject line on the first page of your response. It would also be 
helpful if you provided the name, date, and Federal Register citation 
related to your comments.
     Explain your views as clearly as possible.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Make sure to submit your comments by the comment period 
deadline identified.

II. The Friends of the Earth Petition

    This notice is seeking comment on and information related to a 
petition for an EPA finding and rulemaking and collateral relief from 
the Friends of the Earth. This petition is seeking the regulation of 
lead emissions from piston-powered general aviation aircraft under 
section 231 of the Clean Air Act. The complete petition of Friends of 
the Earth is available from their Web site, the docket, from the EPA 
Web site at: http://www.epa.gov/otaq/aviation.htm, or from the individual 

listed under FOR FURTHER INFORMATION CONTACT above.
    Friends of the Earth is an environmental advocacy organization 
headquartered in Washington, DC. The petition they submitted concerns 
the use of leaded aviation gasoline in piston-powered general aviation 
aircraft in the U.S. Friends of the Earth believes that ``EPA action 
regarding lead in general aviation aircraft is long overdue. Studies 
increasingly show that lead in any quantity threatens the public 
welfare. Lead emissions from general aviation aircraft constitute a 
substantial proportion of all current lead air emissions. As a result 
of the use of leaded aviation gasoline, humans and ecological receptors 
at or near general aviation airports may be exposed to elevated levels 
of lead.''
    Friends of the Earth contends that ``safe unleaded alternatives to 
aviation gasoline do exist. Since 1999, the research and development 
process has produced unleaded fuels that have received approval from 
the FAA for current use. Tens of thousands of low-performance aircraft 
have received supplemental type certificates allowing them to run on 
unleaded automobile gasoline (commonly referred to as mogas in the 
aviation community). Additionally, a mogas alternative, 82UL, has been 
developed for use by some low-performance planes. The combination of 
these two fuels can be utilized by nearly seventy percent of all 
piston-driven aircraft. Additionally, the FAA allows a select number of 
planes to run on an ethanol based aviation fuel (AGE85); the remaining 
thirty percent of general aviation planes can potentially use this 
unleaded gasoline.''
    The Friends of the Earth petition was addressed to EPA. Both EPA 
and the FAA have specific statutorily defined roles regarding aviation. 
EPA through section 231 of the Clean Air Act can make findings 
regarding air pollution emissions from aircraft and set standards 
regulating such emissions and FAA has the statutory authority to 
regulate the fuel used in aircraft (49 U.S.C. 44714). By this Notice, 
EPA is soliciting comment on the petition, specifically on the points 
discussed in the section ``Request for Comments'' presented below. EPA 
will use this information in its statutory assessment of whether lead 
emissions from piston-powered general aviation cause or contribute to 
air pollution that may reasonably be anticipated to endanger public 
health or welfare.

III. Background Regarding Lead in Aviation Fuel

    In a variety of chemical forms and exposure pathways, lead has long 
been recognized as causing serious adverse health effects. In 1978 EPA 
established a National Ambient Air Quality Standard for lead of 1.5 
micrograms per cubic meter, as a maximum quarterly average. Research 
completed since that time, discussed in EPA's Air Quality Criteria 
Document for Lead (2006) indicates that health effects of lead occur at 
blood lead levels lower than those previously reported and include 
concerns not previously studied (available at http://www.epa.gov/ncea). The 

adverse effects of lead include neurotoxic effects (e.g., IQ loss in 
children), effects on the immune system, red blood cell production, 
cardiovascular system, kidney, bones, teeth and reproductive and 
developmental systems. EPA is currently conducting a review of the 
NAAQS which has included the assessment of health and welfare effects 
of lead documented in the Air Quality Criteria Document for Lead 
(2006). Integral to the NAAQS review are decisions regarding the 
adequacy of the current standard for lead and whether the Agency should 
retain or revise it. Consistent with the court order regarding this 
review, the review and regulatory development process will be completed 
by September 1, 2008. Additional information about the review is 
available at: http://www.epa.gov/ttn/naaqs/standards/pb/s_pb_index.html
.

    Thirty-five years ago, cars and trucks were the major contributors 
of lead emissions to the air. In the 1970s, EPA set national 
regulations to gradually reduce the lead content in gasoline. In 1974, 
unleaded gasoline was introduced for motor vehicles equipped with 
catalytic converters. EPA banned the use of leaded gasoline in highway 
vehicles after December 1995. As a result of EPA's regulatory efforts 
to remove lead from gasoline, emissions of lead from the transportation 
sector have dramatically declined (96 percent between 1980 and 2005). 
The large reductions in lead emissions from motor vehicles have changed 
the nature of the air quality lead problem in the United States. 
Industrial processes, particularly primary and secondary lead smelters, 
utility boilers, and battery manufacturers taken together, are now 
responsible for most lead emissions into the atmosphere.
    Currently, tetraethyl lead (TEL) is added to gasoline used in most 
piston-engine powered aircraft. The 2002 National Emissions Inventory 
(NEI) estimates that lead emissions from the use of leaded aviation 
gasoline (commonly referred to as avgas) are 491 tons; this accounts 
for 29 percent of the air pollution emissions inventory for lead, and 
is overall, the largest source category. This estimate is based on the 
Department of Energy estimate of about 281 million gallons of avgas 
supplied in the U.S. in 2002 (data available at http://www.tonto.eia.doe.gov/dnav/pet/hist/mgaupus1A.htm
). In 2006 the volume 

of avgas supplied in the U.S. was about 280 million gallons. The 
majority of avgas contains up to 0.56 grams of lead per liter (2.12 
grams of lead/gallon). This is referred to as 100 Low Lead (100LL). 
There is another grade of 100

[[Page 64572]]

octane avgas that contains 1.12 grams of lead per liter, but this 
product is not widely available.
    According to the Federal Aviation Administration (FAA) General 
Aviation and Air Taxi Activity and Avionics (GAATAA) survey (2005), 
there were over 190,000 piston-engine powered aircraft engaged in 
flight operations in the U.S. in 2005; these aircraft comprised 
approximately 90 percent of the aircraft in the general aviation fleet. 
In 2005, approximately 29 million landing and take-off events (58 
million total operations) were conducted by piston-engine powered 
aircraft. Among the total hours flown by general aviation aircraft, 
about 68 percent occurred in a piston-engine powered aircraft. 
According to the General Aviation Manufacturers Association (GAMA), 
there were approximately 2,750 new piston-engine powered aircraft 
manufactured in 2006. This is the largest production volume over the 
past ten years and reflects an average annual increase in sales that 
ranged from eight to 43 percent during the preceding 10-year period 
except for 2001 and 2002. GAMA estimates that the average piston-engine 
powered aircraft is 35-40 years old.
    Avgas and automotive unleaded gasoline are both derived and blended 
from the refining of petroleum. However, due to the different nature of 
engine designs and operating environments these two types of gasoline 
are different in their chemical composition. Avgas is refined and 
blended to meet ASTM specification D910 while automotive unleaded 
gasoline (commonly referred to as mogas) meets ASTM specification 
D4814. Generally, avgas is transported independent of other fuel to 
avoid cross-contamination and to maintain the tight specifications of 
avgas required for proper engine operation in general aviation 
applications. TEL is added to avgas to increase octane, prevent 
knock,\1\ and prevent valve seat recession and subsequent loss of 
compression for engines without hardened valves. Lead and other 
additives are added downstream of the refinery; most avgas is 
distributed by truck directly from the refinery to the bulk gasoline 
terminals or bulk plants or to the storage tanks and refueling 
equipment at airports.
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    \1\ Knocking is the sound produced when some of the unburned 
fuel in the cylinder ignites spontaneously resulting in rapid 
burning and a precipitous rise in cylinder pressure that creates the 
characteristic knocking or pinging sound (Chevron 2005 available at: 
http://www.chevronglobalaviation.com/docs/aviation_tech_review.pdf
).

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    Most piston engines used in general aviation are type certified by 
FAA for the use of leaded avgas (mostly 100LL). The FAA has issued 
supplemental type certificates (STCs) qualifying piston engines used in 
general aviation to use unleaded avgas. There are two types of unleaded 
gasoline reflected in these STCs. The first type of unleaded gasoline 
which can be used under STCs is ethanol-free unleaded automotive 
gasoline (mogas). Most aircraft using this mogas have low-compression 
engines which were originally certified to run on leaded 80/87 avgas 
and require only 87 antiknock index gasoline. The second type is known 
as 82UL avgas, which is unleaded fuel similar to automobile gasoline 
but without additives. It may be used in aircraft that have an STC for 
the use of automobile gasoline with an aviation lean octane rating of 
82 or less or an antiknock index of 87 or less. ASTM specification 
D6227 has been established for 82UL but this fuel has not yet been 
produced for general distribution.\2\ About 97 percent of gasoline used 
in piston-engine powered aircraft is leaded avgas, mostly 100LL. The 
remaining three percent is ethanol-free unleaded automotive gasoline 
(mogas).
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    \2\ 82UL has not yet been produced for general distribution due 
to limited demand. It would be a fraction of the 100LL market. It is 
an aviation grade product, and thus, refiners can not simply alter 
mogas to make 82UL.
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    The Experimental Aircraft Association and Petersen Aviation 
estimate that ethanol-free unleaded gasoline can be used in 
approximately 40 percent of the piston-engine powered aircraft fleet 
(e.g., those aircraft with low-compression engines).\3\ In contrast, in 
order to prevent knock or detonation during the combustion process, 
high-compression piston engines require higher octane than typical 
unleaded gasoline provides. These aircraft also typically have higher 
utilization rates and fuel consumption rates than their low-compression 
counterparts. The AOPA estimates that high-compression piston-engine 
powered aircraft currently consume approximately 70 percent of the 
leaded avgas supplied nationally, and that the remaining 30 percent of 
the leaded avgas is used in aircraft that could also use ethanol-free 
unleaded automotive gasoline.
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    \3\ The Experimental Aircraft Association and Petersen Aviation 
data are available at http://www.aviationfuel.org and www.autofuelstc.com/

autofuelstc/pa/PetersenAviation.html.
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    Efforts to explore reduced lead emissions from piston-engine 
powered aircraft have primarily focused on fuels to replace 100LL 
avgas, with less attention given to potential engine modifications. The 
FAA conducts research exploring replacement fuels for use in piston-
engine powered aircraft at its William J. Hughes Technical Center. 
Publications from this research can be found at http://www.actlibrary.tc.faa.gov/
 by searching for `unleaded avgas'. The 

Coordinating Research Council has organized the Unleaded Aviation 
Gasoline Development Group which brings together FAA, AOPA, GAMA, the 
Experimental Aircraft Association, airframe manufacturers, engine 
manufacturers, fuel producers and other interested parties. The 
objective of the group is to facilitate development of a high-octane 
unleaded aviation gasoline as an environmentally compatible, cost-
effective replacement for the current 100LL avgas. Documents regarding 
the CRC Unleaded Aviation Gasoline Development Group can be found in 
the docket for this notice.
    At the 23rd World Assembly of the International AOPA, Lennart 
Persson of Hjelmco Oil in Sweden suggested that a 91/96 octane unleaded 
avgas could be a transparent switchover for 70 percent of the U.S. 
general aviation fleet. He indicated that this fuel would provide 
similar performance to 100LL avgas and has done so successfully in 
Sweden for 15 years. It is now offered for sale at 70 locations in 
Sweden. For more information see http://www.iaopa.org/info/assembly23/ppts/persson.pdf



IV. Request for Comments

    EPA is soliciting public comment on any and all aspects of the 
petition from Friends of the Earth regarding issues related to the use 
of lead in general aviation gasoline. To assist us in developing our 
response to the petition EPA specifically requests information and 
comment on the following.
    1. EPA requests information related to human and environmental lead 
exposures and effects around airports. Specifically, we request 
information on concentrations of lead in the air, soil, surface water 
or other environmental media at or near airports where leaded avgas is 
used. Information regarding sources of lead in addition to leaded avgas 
in these areas is also requested.
    2. We request information on levels of lead in indoor dust in homes 
in the vicinity of airports where leaded avgas is used and information 
regarding the presence of leaded paint in those homes.
    3. We request information on blood lead levels in children and 
adults residing or attending school in the vicinity of an airport where 
leaded avgas is used.

[[Page 64573]]

    4. We request information on the characteristics of the populations 
residing in the vicinity of an airport where leaded avgas is used, 
specifically, information regarding the number of children six years 
and younger, the number of schools, daycare facilities, retirement 
homes, and the socioeconomic status of the population.
    5. EPA request information on the volume of leaded avgas and 
unleaded aviation gasoline (mogas) supplied at individual airports 
nationwide.
    6. EPA requests comment on locations where unleaded aviation 
gasoline is available and the reason for its apparent lack of 
widespread availability. We request the submission of information 
related to supplying unleaded aviation gasoline at airports and how 
potential fuel distribution issues could be addressed.
    7. EPA requests information on the characteristics of piston engine 
general aviation operation, including annual LTOs by airport, LTO 
characteristics per airport and aircraft/engine type including mode, 
time-in-mode, and fuel flow rate in mode. Related to this, EPA requests 
information on the frequency and duration of local area flights 
(including touch/go operations) and flight durations within the mixing 
layer.
    8. EPA requests information on the disposal of leaded avgas after a 
pilot checks the fuel before starting the aircraft. Specifically, we 
request information on how this fuel is discarded (i.e., is it 
deposited on the tarmac) or otherwise handled?
    9. Leaded avgas contains ethylene dibromide which acts as a 
scavenger for lead by converting lead oxide to lead bromide compounds 
which are volatile and easily exhausted from the engine. This prevents 
lead oxide depositing on the valves and spark plugs where it could 
damage the engine. EPA requests information on the variation in lead 
emission rates at various operating modes and power settings and the 
quantity of lead retained in the engine and engine oil as a fraction of 
the lead in the fuel combusted.
    10. EPA is requesting comments on the potential use of replacement 
fuels for use in piston-engine powered aircraft. Approximately 40 
percent of the piston-engine powered aircraft fleet is certified with 
an STC allowing the use of ethanol-free unleaded gasoline (82UL or 
``mogas''), but these fuels are not widely available at airports. 
Information available to EPA suggests that 30 percent of the 100LL 
avgas consumed could be replaced by unleaded gasoline. These aircraft 
are equipped with low-compression engines that may also run on leaded 
aviation fuel when mogas or 82UL is not available.
    11. We request analysis of the prospects for developing an unleaded 
fuel for the general aviation fleet that will meet the needs of high-
compression engines, including additional research needed.
    12. EPA is requesting comment on the viability of a high-octane 
unleaded aviation gasoline in a high-compression engine to provide 
equivalent performance and safety to 100LL avgas.
    13. In this context, EPA requests comment on the viability of the 
use of ethyl tertiary-butyl ether (ETBE) or other octane enhancing 
compounds for unleaded fuel.
    14. We also request information on what modifications would need to 
be made to the existing fleet of high-compression engines as well as 
new engines, with appropriate lead time, for them to operate on high-
octane unleaded fuel with an equivalent margin of safety. In 
particular, we solicit comment on electronic ignition systems (full 
authority digital engine control) and knock (detonation) sensors, 
including comments on further research on these technologies. One 
example for consideration is the Teledyne Continental Motors/Aerosance 
Powerlink FADEC system.
    15. EPA also requests information on the ability of current engines 
to operate on avgas with a decreased lead content relative to 100LL, 
and identification of the minimum lead content needed to maintain safe 
engine operation.
    16. EPA requests comment on the storage of avgas, specifically, 
issues related to above ground storage capacity compared to below-
ground storage capacity.
    17. EPA requests comment on the availability of additives less 
toxic than lead to enhance aviation gasoline octane.
    18. We request comment on the long-term availability of TEL as an 
avgas additive.
    19. We request information related to the feasibility and costs of 
any potential options for limiting lead emissions from existing 
aircraft.
    20. We request comment on the STCs which have been approved to 
allow for the use of unleaded gasoline in general aviation, the percent 
and characteristics of the current fleet covered by STCs, and obstacles 
to wider acceptance and application of the STCs.
    21. EPA is requesting comment on additional research on alcohol-
based fuels of which we should be aware. The FAA has approved a very 
limited number of STCs for use of ethanol-based AGE-85 fuel (85% 
ethanol in 15% unleaded gasoline) under a preliminary fuel 
specification. Subsequent approvals allowing more widespread use of 
AGE-85 are pending the development of a final, aviation-grade fuel 
specification to ensure potential safety concerns with the fuel are 
fully vetted by the FAA and the aviation industry.
    22. EPA is requesting comment on additional research or information 
regarding the use of diesel engines in general aviation, particularly 
regarding equipment changes and the related costs. The FAA has approved 
Type Certificates and STCs for diesel-cycle engines that use widely-
available, unleaded jet fuel.
    Before the end of the comment period, please send all comments and 
related information to the address indicated in the ADDRESSES section 
at the beginning of this notice.

    Dated: November 9, 2007.
Stephen L. Johnson,
Administrator.
[FR Doc. E7-22456 Filed 11-15-07; 8:45 am]

BILLING CODE 6560-50-P
