MTBE controversy

Methyl tert-butyl ether (MTBE) is a gasoline additive used as an oxygenate and to raise the octane number. Its use has declined in the United States in response to environmental and health concerns. It has polluted groundwater due to MTBE-containing gasoline being spilled or leaked at gas stations. MTBE spreads more easily underground than other gasoline components due to its higher solubility in water.^[1] Cost estimates for removing MTBE from groundwater and contaminated soil range from $1^[2] to $30^[3] billion, including removing the compound from aquifers and municipal water supplies, and replacing leaky underground oil tanks. Who will pay for remediation is controversial. In one case, the cost to oil companies to clean up the MTBE in wells belonging to Santa Monica is estimated to exceed $200 million.^[4]

Recent state laws have been passed to ban MTBE in certain areas. California and New York, which together accounted for 40% of U.S. MTBE consumption, banned the chemical starting January 1, 2004, and as of September 2005, twenty-five states had signed legislation banning MTBE. A table of state by state information, as of 2002, is available at the United States Department of Energy website.^[5]

In 2000, the EPA drafted plans to phase out the use of MTBE nationwide over four years. As of fall 2006, hundreds of lawsuits are still pending regarding MTBE contamination of public and private drinking water supplies.

The Energy Policy Act of 2005, passed in the House on April 21, 2005, did not include a provision for shielding MTBE manufacturers from water contamination lawsuits. This provision was first proposed in 2003 and had been thought by some to be a priority of Tom DeLay and Rep. Joe Barton, chairman of the Energy and Commerce Committee.^[6] This bill did include a provision that gives MTBE makers, including some major oil companies, $2 billion in transition assistance as MTBE is phased out over the next nine years.^[7] Due to opposition in the Senate,^[8] the conference report dropped all MTBE provisions. The final bill was passed by both houses and signed into law by President Bush.^[9] The lack of MTBE liability protection is resulting in a switchover to the use of ethanol as a gasoline additive, which is in limited supply as of April 2006. Some traders and consumer advocates are blaming this for an increase in gasoline prices.^[10]

The EPA currently lists methyl tertiary butyl ether (MTBE) as a candidate for a maximum contaminant level (MCL) in drinking water.^[11] MCLs are determined by the EPA using toxicity data.

Notable incidents in the US

Fallston, Maryland

Former location of Exxon station in Fallston, Maryland

Harford County, Maryland, found MTBE in wells near several of its filling stations beginning in 2004.^[12] This led the state of Maryland to make moves to ban MTBE.^[13][14][13]

In 2005, an Exxon-Mobil station in Fallston, Maryland, was found to be leaking MTBE into the local wells. The discovery resulted in the station being abruptly closed.^[15] Exxon-Mobil referred to the closure as a "business decision".^[15] Following the closure, MTBE levels in the area dropped.^[16]

In September 2004, Harford County placed a six-month moratorium on construction of filling stations.^[17]

Jacksonville, Maryland

In 2006, the wells of a neighborhood in Jacksonville, Maryland, were contaminated by a spill of 26,000 gallons from an Exxon-Mobil station in the area, resulting in an ongoing court battle.^[18][19] The suit has been filed by the state of Maryland's department of the environment on behalf of the area's residents, seeking millions of dollars in damages from Exxon-Mobil.^[20] Many residents also filed their own separate lawsuits.^[21]

The case began in 2006, when a gasoline tank sprang a leak that was not detected for 34 days. Testing of 120 wells resulted in dangerously high levels of MTBE being found.^[22] Residents were put in danger by the spill, and in order to prevent further health problems, they required bottled water for cooking, drinking, and brushing teeth.^[23] Residents of Jacksonville continue to use bottled water for all activities despite having MTBE filters and alarms installed in their homes. Home values also dropped as a result of the spill.^[24]

In September 2008, Exxon-Mobil settled the case with the state by agreeing to pay a $4 million fine, and face an additional $1 million in penalties annually if they did not work to clean up the spill.^[25]

In March 2009, a jury awarded $150 million in damages to some of the area's residents. The jury did not assess any punitive damages in the case, finding that Exxon Mobil did not act fraudulently.^[26] A separate case including over 150 property owners as plaintiffs began in early 2011. Punitive damages were awarded to the second group of plaintiffs, who were able to prove that Exxon DID act fraudulently.^[27]

Santa Monica, California

In 1995 high levels of MTBE were unexpectedly discovered in the water wells of Santa Monica, California, and the U.S. Geological Survey reported detections.^[28] Subsequent U.S. findings indicate tens of thousands of contaminated sites in water wells distributed across the country. As per toxicity alone, MTBE is not classified as a hazard for the environment, but it imparts an unpleasant taste to water already at very low concentrations. The maximum contaminant level of MTBE in drinking water has not yet been established by the United States Environmental Protection Agency (EPA). The leakage problem is partially attributed to the lack of effective regulations for underground storage tanks, but spillage from overfilling is also a contributor. As an ingredient in unleaded gasoline, MTBE is the most water soluble component. When dissolved in groundwater, MTBE will lead the contaminant plume with the remaining components such as benzene and toluene following. Thus the discovery of MTBE in public groundwater wells indicates that the contaminant source was a gasoline release. Its criticism and subsequent decreased usage, some claim, is more a product of its easy detectability (taste) in extremely low concentrations (ppb) than its toxicity. The MTBE concentrations used in the EU (usually 1.0–1.6%) and allowed (maximum 5%) in Europe are lower than in California.^[29]

Chevron, BP, and other oil companies agreed to settle with Santa Monica for $423 million on May 7, 2008.^[30]

See also

• List of environmental issues
• Environmental issues in the United States

References