A July 26 Wall Street Journal editorial (subscription required) understated the extent to which the gasoline additive methyl tertiary-butyl ether (MTBE) has leaked into drinking water supplies and downplayed the health risks associated with ingesting MTBE. The Journal attacked "water companies and some cities" that have sued MTBE producers and fuel companies that use MTBE, claiming that only "trace amounts" of MTBE have leaked into water supplies and that "such small contaminations are harmless to public health." In fact, there have been numerous contaminations exceeding acceptable levels set by state governments and recommended by the Environmental Protection Agency (EPA), and MTBE is considered a potential carcinogen, though its low-level toxicity is undetermined.
As fuel additives, MTBE and ethanol are considered "oxygenates," because they raise the oxygen content of gasoline, allowing it to burn more cleanly and efficiently. Since 1992, MTBE has been used in higher concentrations in gasoline, in accordance with 1990 Clean Air Act amendments calling for higher oxygenate content in gasoline to reduce harmful vehicle emissions; as the Journal noted, most fuel companies have used MTBE instead of ethanol because it is less expensive to produce.
Numerous MTBE leaks -- primarily from underground gasoline tanks -- have contaminated drinking water supplies across the nation. The EPA has cited MTBE's effect on water quality as a reason to "significantly reduce or eliminate MTBE" as a fuel additive. The Journal criticized the 2005 Energy Policy Act as a "subsidy-fest that will raise gasoline prices in more places than it reduces them," but defended language written into the House version of the bill providing MTBE producers liability protection, and questioned the merit of lawsuits filed against them:
Fast-forward to the mid-1990s, when ethanol production had grown and gasoline leaks from older, underground tanks had led to trace amounts of MTBE in some water supplies. While such small contaminations are harmless to public health (especially as MTBE is easy to detect and therefore to avoid), water companies and some cities have pounced like trial lawyers on MTBE makers with the deepest pockets.
Refiners and other companies now face more than 100 lawsuits, even as they are striving to meet growing energy demand and more elaborate fuel specifications. Draining cash from these companies to finance trial-lawyer contingency bonanzas will not lower gas prices.
The Journal correctly noted that "trace amounts" of MTBE are harmless, even though "such small contaminations" are enough to imbue water with a taste and odor reminiscent of turpentine -- perhaps the reason why the Journal characterized MTBE as "easy to detect and therefore avoid." But in making this claim, the editorial understated the nature of MTBE leaks nationwide. There have been numerous leaks resulting in MTBE concentrations in drinking water greater than the "trace amounts" the Journal claimed; these concentrations exceed suggested EPA standards as well as acceptable standards set by various states, including California and Pennsylvania.
A 1997 EPA Drinking Water Advisory on MTBE suggested that "keeping levels of contamination in the range of 20 to 40 µg/L [micrograms per liter, or parts per billion (ppb)] or below to protect consumer acceptance of the water resource would also provide a large margin of exposure (safety) from toxic effects." Pennsylvania's acceptable MTBE concentration for drinking water is 20 ppb, while California's is 13 ppb. Higher contaminations are potentially harmful; an EPA document on MTBE notes that "available data are not adequate to estimate potential health risks of MTBE at low exposure levels in drinking water but that the data support the conclusion that MTBE is a potential human carcinogen at high doses."
An EPA document on MTBE water contamination noted that in 1996, two wellfields supplying Santa Monica, California, with half of its drinking water were found to be "contaminated with MTBE at levels as high as 610 ppb and 86 ppb." A November 19, 2003, San Francisco Chronicle article reported that the South Lake Tahoe, California, water utility shut down 12 of its 34 wells after MTBE concentrations exceeding California's acceptable contamination level were discovered.
There are numerous reports of localized, high-dose contaminations as well:
- A December 14, 1998, San Francisco Chronicle article noted that Glennville, California, was spending $5,000 per month to provide fresh water to nine homes and one business "after tests found MTBE levels as high as 20,000 parts per billion (ppb) in one well."
- An October 24, 2000, Philadelphia Inquirer article reported that in Doylestown, Pennsylvania, MTBE contamination from leaking gasoline tanks at two service stations was so extensive that "[s]ome of the seven contaminated wells were found to have MTBE levels as high as 2,090 parts per billion." Pennsylvania's acceptable MTBE limit is 20 ppb.
- A November 4, 2000, Philadelphia Inquirer article reported that five wells in Warminster, Pennsylvania, "showed levels of MTBE between 180 and 525 parts per billion."
- The New York Times reported on February 14, 1995, that of the two MTBE-contaminated wells servicing the Silver Stream Village mobile home park in New Windsor, New York; one "contained 2,900 parts per billion, the other 1,300."
- A June 23, 2004, Baltimore Sun article reported that the MTBE concentration in eight wells near a gasoline station in Fallston, Maryland, exceeded 20 ppb, including one that reached 347 ppb.
The EPA further documented that MTBE "migrates faster and farther in the ground than other gasoline components, thus making it more likely to contaminate public water systems and private drinking water wells."