EPA Ignored Its Own Scientists on MTBE

Published January 1, 2000

When an EPA-appointed blue-ribbon panel announced last summer it was recommending that use of the gasoline additive MTBE be “reduced substantially,” the curtain began falling on one of the most bizarre–and avoidable–missteps in recent U.S. environmental policy.

The panel’s announcement came in the wake of growing public concern about the presence of MTBE (methyl-tertiary butyl ether) in drinking water systems from Maine to California. With MTBE leaking from gas stations and underground storage tanks into groundwater supplies, EPA had a problem on its hands. Even though most detections have been well below levels that could pose a risk to public health, the uproar over drinking water contamination was enough to force EPA to abandon one of the pillars of its reformulated gasoline (RFG) program.

In the aftermath of the MTBE debacle, it has now come to light that EPA could have spared itself much embarrassment–and affected communities much anxiety–had the agency heeded repeated warnings from its own scientists. Those scientists warned that the chemical properties of MTBE made it likely that, if leaked or spilled, the gasoline additive would find its way into groundwater, where it would quickly spread.

Chain of events

Little thought appears to have been given this possibility when in 1990, Congress amended the Clean Air Act (CAA). One of those amendments instructed EPA to develop an RFG program for cities with persistent air quality problems. The goal was to reduce carbon monoxide emissions from cars and trucks.

EPA unveiled its reformulated gasoline program with great fanfare in 1993. The agency mandated the use of what it said were cleaner-burning oxygenated fuels in 39 metropolitan areas in 16 states beginning in 1995.

In accordance with EPA’s RFG policy, oil companies were required to supply the targeted cities with oxygenated fuels. While some oil refiners chose corn-based ethanol, most decided to use octane-boosting MTBE. When added to standard gasoline, MTBE raises its oxygen content, which in turn reduces emissions of carbon monoxide, particularly in older vehicles.

MTBE did in fact improve the air quality in the cities where it was used but, as is now abundantly clear, it did so at a cost that negated whatever benefits it achieved.

Had EPA taken the trouble to familiarize itself with MTBE, it would have noticed an unsettling characteristic of the gasoline additive. Unlike standard gasoline, which when spilled or leaked does not spread far and breaks down over time, MTBE is highly soluble in water. Once it reaches groundwater it spreads rapidly.

Precisely this point was made by a group of EPA scientists in a report issued for external review in December 1992. The report, “Alternative Fuels Research Strategy” (EPA: 600-AT-92/002), established a comparative framework for risk assessments of MTBE, ethanol, ETBE, methanol, and compressed natural gas.

Written in the hope that its findings would generate interest at EPA in a full-fledged research program targeted at alternative fuels, the report was reviewed by the agency’s Clean Air Scientific Advisory Committee (CASAC) in the summer of 1993. Afterwards, it simply gathered dust at the agency. Its warnings about MTBE and groundwater went unheeded, as did those of a second group of scientists at EPA’s laboratory in Athens, Georgia.

Confirming the worst fears of EPA scientists, MTBE was detected in the water system of Santa Monica, California in 1996, a result of leaks from gas stations and underground storage tanks. By 1998, MTBE had been found in groundwater at over 10,000 locations throughout central and northern California. Before long, the gasoline additive had turned up in water systems in New Jersey, New York, Connecticut, Rhode Island, and other states under EPA’s RFG mandate.

With political pressure building in affected communities and in Congress to do something about MTBE-contaminated drinking water, EPA Administrator Carol Browner convened the blue-ribbon panel to investigate the matter.

Cleaning up the mess

In the wake of EPA’s MTBE misadventure, Browner’s agency has many questions to answer: Why did EPA ignore the warnings of its own scientists that MTBE could contaminate groundwater? Why did the agency launch a nationwide reformulated gasoline program without having thoroughly researched the health effects of the fuels it was enthusiastically imposing on many of the nation’s consumers? And why, when problems first surfaced in Santa Monica, did EPA wait two years before it authorized a blue-ribbon panel to review the data on MTBE?

With cutbacks pending in MTBE production, EPA’s entire reformulated gasoline program is in jeopardy. While Midwestern farmers may welcome the demise of MTBE, their hopes of filling the gap with corn-based ethanol are not considered realistic by energy experts. Currently, MTBE has 85 percent of the reformulated fuels market, and industry observers doubt that enough ethanol can be produced to make up the difference.

The situation could become particularly acute in California, where Governor Gray Davis (D) has ordered the phase-out of MTBE by 2002. Ethanol cannot be sent by pipeline and would have to be shipped to California by tankers at great expense. Additional port facilities would have to be built to off-load the fuel. In short, California remains under the CAA’s RFG mandate, with no fuels at its disposal with which to comply with the law.

What’s more, oil companies spent $7 billion retrofitting their refineries to produce MTBE for EPA’s RFG program. Many now face the distinct possibility that they will never recoup that investment.

Bonner Cohen is a senior fellow at the Lexington Institute in Arlington, Virginia.