Control of MTBE in Gasoline
Oxygenates in Gasoline
Congress required, in the Clean Air Act of 1990, that areas of the country with
the worst ozone smog problems use reformulated gasoline (RFG) with an increased
oxygen content of 2 percent. Seventeen states and the District of Columbia presently
use reformulated gasoline (RFG), either because of the Congressional mandate, or
because some areas have voluntarily chosen to use RFG to help achieve their clean
air goals. Methyl tertiary-butyl ether (MTBE) is the oxygen additive most commonly
used by the petroleum industry to satisfy the 2 percent oxygen mandate. MTBE is
used in approximately 87 percent of RFG, with ethanol being the second most com-
monly used additive. Of those areas listed below, only Milwaukee and Chicago use
primarily ethanol to meet the oxygen requirement.
Areas Required to Use RFG
Los Angeles, CA
San Diego, CA
Hartford, CT
New York City (NY-CT-NJ)
Greater Philadelphia (PA-NJ-DE-MD)
Chicago (IL-WI-IN)
Baltimore, MD
Houston, TX
Milwaukee, Wl
Sacramento, CA
Areas That Have Voluntarily Chosen to Use RFG
The State of Connecticut (that portion not part of NYC)
The State of Delaware (that portion not part of Phil.)
The District of Columbia
Kentucky portion of Cincinnati Metro Area
Louisville, KY
Maryland - DC suburbs and two other nearby counties
The State of Massachusetts
St. Louis, MO
New Hampshire Portion of Greater Boston
The State of New Jersey (that portion not part of NYC
and Phil.)
New York counties near NYC
The State of Rhode Island
Texas - Dallas-Fort Worth area
Virginia - DC suburbs, Richmond, Norfolk-Virginia Beach-
Newport News
SEPA
United States
Environmental Protection
Agency
Office of Transportation and Air Quality
EPA-420-F-00-010
March 2000
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Since the late 1970s, MTBE also has been used by the petroleum industry in much smaller
amounts as an octane enhancer to replace lead. Approximately 4.5 billion gallons of MTBE are
used each year in gasoline (275,000 barrels per day out of a total of 8.2 million barrels/day of
gasoline), an increase of more than three times since Congress's 1990 mandate.
MTBE in Water
Since MTBE is very soluble in water and does not "cling" to soil well, it has a tendency to
migrate much more quickly into water than other components of gasoline. Recent testing by
the United States Geological Survey show detections of MTBE in approximately 20 percent of
the ground water in REG areas, while there is only a 2 percent detection rate in non-RFG areas.
Most of these detections are below the levels of public health concern and are within the range
EPA has set for a taste and odor water advisory for MTBE at 20 to 40 parts per billion. Small
individual fuel spills and storm water runoff contribute to detections of MTBE in water supplies,
MTBE detections at high concentrations usually result from leaking underground or above-
ground fuel storage tanks and pipelines. Even though significant air quality gains have been
made using REG, these air benefits can be maintained without using MTBE and without endan-
gering the nation's water resources.
MTBE Call to Action
In response to the growing concerns regarding MTBE in water, EPA Administrator Browner
appointed an independent Blue Ribbon Panel of experts to investigate the use of oxygen
additives in gasoline. The Panel called for significant reduction in the use of MTBE in gasoline
and recommended that Congress and EPA take action to lift the oxygen mandate and clean up
CjjJ MTBE contamination. EPA fully supports the Panel recommendations and is taking steps to
strengthen its underground storage tank, safe drinking water, remediation, and research programs.
Upon release of the Panel's report in September 1999, EPA immediately began working with
and encouraging Congress to pass legislation that responded to the Panel's recommendations.
To date, legislation that would solve this problem has not moved forward. EPA is now providing
Congress with a framework for legislation that will give EPA the authority to significantly reduce
or eliminate MTBE. EPA is also taking action to control MTBE under the Toxic Substances
^^\^ Control Act (TSCA) as a backup to the needed Congressional action. A TSCA rulemaking is
I , procedurally burdensome and may take several years to complete,
Ethanol Use Will Expand
Current annual ethanol production is about 1.5 billion gallons. Of this total, about 30 percent
is used in RFG during the summer in Federally designated non-attainment areas. About 20
percent of ethanol production is used in the winter oxygenate program in Federally designated
areas where carbon monoxide is a problem. The remaining 50 percent of production is used in
conventional gasoline markets around the United States to enhance octane and extend fuel
supplies.
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With the March 20, 2000, announcement by Secretary Glickman and Administrator Browner,
ethanol use is expected to continue to grow. Provided air quality gains achieved to date are not
reduced, ethanol will continue to be used very much as it is used today. In areas of the country
where it is heavily used, ethanol will continue to be favored based on its price, availability and
environmental benefits. Other areas may also find ethanol to be an economic way to maintain
air quality benefits that had been achieved with the use of MTBE. Without the renewable fuels
standard, some petroleum-based substitutes for ethanol may emerge over time. The proposed
renewable fuels standard would ensure that the current market for ethanol would be maintained
and expand over time.
The renewable fuels standard will be met through the use of fuels made from a variety of renew-
able feedstocks. While most ethanol now is made from corn, other crops, such as wheat and
sorghum, have and could also be used. In addition, new conversion technologies now in devel-
opment are expected to be available in the future for efficient conversion of cellulosic material
to ethanol. These technologies would make possible the broader use of a wide array of renewable
feedstocks, including agricultural waste and residue, such as corn stalks, and dedicated crops,
such as switchgrass.
The President has set a goal to triple U.S. use of biobased products and bioenergy by 2010. The
Administration's FY 2001 budget proposes an increase of $96 million (56 percent) to support
biobased products and bioenergy research and development, demonstration and commercializa-
tion, and outreach and education activities. The President also directed USDA's Commodity
Credit Corporation to provide up to $100 million in FY 2000 and up to $150 million in 2001
and 2002 in incentive payments to ethanol and other bioenergy producers to expand production
of biobased fuels. Payments will be made on a portion of the increase in agricultural commodities
purchased for expanded bioenergy production, with smaller and cooperatively-owned facilities
receiving higher payment rates.
For More Information
You can access documents on MTBE electronically on the Office of Transportation and Air
Quality web site at:
www.epa.gov/otaq/consumer/fuels/mtbe/mtbe.htm
You can also contact the NVFEL library for document information at:
U.S. Environmental Protection Agency
Office of Transportation and Air Quality
NVFEL Library
2000 Traverwood Drive
Ann Arbor, MI 48105
(734)214-4311
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