The Challenge of MTBE: Clean Air vs. Clean Water?
Clean air vs. clean water sums up the controversy surrounding the gasoline additive methyl tertiary butyl ether (MTBE), an oxygenate designed to help fuel burn cleaner, reducing tailpipe emissions. Since 1996, the year it was first used statewide on a year-round basis, MTBE has reduced smog from motor vehicles by 15 percent, according to air quality officials. It’s as if 3.5 million cars have disappeared from the roads – no small feat in the automobile – dependent Golden State.
For the state’s water resources, however, MTBE is the latest in a long line of contaminants that threaten the quality of groundwater aquifers and drinking water reservoirs. MTBE has been detected in shallow groundwater aquifers near leaking underground fuel tanks and its solubility in water concerns some that it could move to deeper, drinking water aquifers. Several California communities already are coping with MTBE contamination in drinking water wells, including the city of Santa Monica, which lost 50 percent of its local supply when MTBE contamination forced the closure of nine wells. Other water suppliers, meanwhile, are struggling to balance the recreational and domestic demands on drinking water reservoirs – boaters have fought attempts to ban two-stroke engines even as regulators consider adopting a regulatory standard for MTBE in drinking water.
The issue is further complicated by a number of factors, including:
- MTBE has helped reduce air levels of benzene, a known human carcinogen, by 50 percent. MTBE itself, however, is suspected of causing cancer in rodents, although no human data is available at this time.
- Beyond the questions of health effects, tests have shown that consumers can detect the turpentine-like odor and taste of MTBE at extremely low concentrations.
- Federal air standards require the use of an oxygenate in gasoline in certain regions, including much of California. While there are other choices of fuel oxygenates, oil refiners say it will be costly to convert from MTBE. And in light of MTBE’s unforeseen effects on water quality, health officials are cautious about such a switch.
“MTBE poses a vexing problem,” said Walt Pettit, executive director of the State Water Resources Control Board (State Board), which regulates water quality in California. “While its positive effects at restoring our air quality have been well documented, it is just one of many chemicals that we don’t want in our drinking water at any level.”
MTBE is a colorless chemical compound found in reformulated fuels to reduce smog and meet federal Clean Air Act standards. About 11 percent of each tank of gas is MTBE. Unlike other fuel compounds, MTBE is highly soluble and migrates with groundwater – dissolved in the water rather than sticking to the soil – and does not break down very quickly.
Currently, there is no primary federal or state health standard for MTBE. The state has established an interim action level of 35 parts per billion (ppb) and a secondary standard of 5 ppb for taste and odor. A primary, health effects based standard is due in July 1999; a public health goal has been set at 14 ppb by the state Office of Environmental Health Hazard Assessment. The U.S. Environmental Protection Agency (EPA) has issued a drinking water advisory level (based on taste and odor) of 20 ppb to 40 ppb. According to the Association of California Water Agencies (ACWA), taste tests have shown that MTBE can be detected at levels lower than either advisory level, which can render drinking water unacceptable to consumers.
The debate over use of MTBE, its health effects and how to prevent and treat MTBE water contamination heightened with the June release of a report by the Lawrence Livermore National Laboratory (LLNL). In a study funded by the State Board, Department of Energy and Western States Petroleum Association (WSPA), scientists determined that MTBE is a frequent and widespread contaminant in shallow groundwater at leaking underground fuel storage tanks throughout California. Two findings are particularly worrisome for water purveyors: MTBE plumes in groundwater have the potential for widespread contamination because MTBE is more soluble in water than other chemicals in gasoline; and MTBE has the potential to persist in groundwater for years because no evidence of a natural chemical break down of MTBE was found.
“MTBE has the potential to impact regional groundwater resources and may present a cumulative contamination hazard,” researchers said in the executive summary of the LLNL report. “The potential long-term accumulation of MTBE plumes may be a key consideration for management of specific regional groundwater basins.”
In most years, groundwater supplies 25 percent to 30 percent of the state’s water. In drought years, groundwater usage can climb to as much as 60 percent, and many communities are wholly reliant on underground aquifers to meet drinking water needs.
In recent weeks, a number of newspaper editorials have called for the removal of MTBE from California’s gasoline. “What we have is a horrendous environmental trade-off,” the Oakland Tribune said in a June 24 editorial. “MTBE has in a small way helped to clear California’s air, but it now appears the gasoline additive poses a serious threat to drinking water supplies. That’s not acceptable.”
At the federal level, however, legislation to change the Clean Air Act (HR 630) and allow California to discontinue the use of fuel oxygenates like MTBE has run into opposition from the Clinton administration, some environmental groups and proponents and manufacturers of fuel oxygenates.
“This bill would have a detrimental effect on air quality and the economy in California,” said Roger Seward, chair of the American Methanol Institute, testifying in April against HR 630. “In the past year, Californians from San Diego to San Francisco have been breathing the cleanest air in four decades.” Methanol is used to manufacture MTBE. MTBE is the largest market for methanol and California is the largest user of MTBE.
At the state level, a 1997 bill that would have banned the use of MTBE was ultimately amended to require several studies into the occurrence and risk of MTBE. The studies are due to the governor on Jan. 1, 1999. Other legislation establishing water contamination remediation funds and requiring the state to establish an MTBE drinking water standard also were signed into law. An Assembly bill to restrict the use of two-stroke engines on some drinking water reservoirs remains unpassed. As this Western Water went to press, a measure to provide funding for water systems MTBE-related costs was pending.
According to WSPA, California refiners spent between $4 billion and $5 billion to modify their refineries to manufacture gasoline that complies with federal and state requirements, choosing MTBE as the oxygenate of choice in large part because it blends well with gasoline and can be distributed through existing underground pipeline systems. As for discontinuing its use, WSPA says the combination of state and federal requirements leave the oil industry with little choice to meet clean fuels standards other than with MTBE unless a change is made in the federal Clean Air Act. “We’re very adamant that the maximum amount of flexibility be built into the law so the refineries can decide if they want to add an oxygenate and what oxygenate,” said Jeff Wilson of WSPA.
As water quality officials continue to monitor for MTBE’s presence in groundwater aquifers and look for ways to keep MTBE out of drinking water supplies, the debate over MTBE has become one of risks vs. benefits.
By Sue McClurg
A complete copy of this article is available from the Water Education Foundation for $3. Contact the Foundation and request the July/August 1998 issue of Western Water or order this issue online on our products page.
As I watched Interior Secretary Bruce Babbitt take a sledge hammer to a small dam in northern California, I knew those of us gathered together were watching an event signaling a change in how water is celebrated in the West. This was a different kind of ribbon cutting ceremony than usually seen at a dedication. Now from Maine to California, the secretary has been making a point of participating in these dam destruction ceremonies. He’s made it clear that he is not on a crusade to abolish all dams, but is looking for new ways mutual needs can be accommodated to the benefit of all. Environmental restoration is the name of the game now with agencies like the Army Corps of Engineer and the Bureau of Reclamation racing to restore the environment almost in the same way they raced to build the dams in the earlier part of the century.
In cases like the tearing down of the half-century-old McPherrin Dam in northern California, the dismantling is seen as positive because it benefits salmon without hurting the main water user, the McPherrin family, who will get water from another diversion. So where water users and environmentalists can agree to remove dams, we will see this scene repeated across the country. However, where there is no consensus, there will be fights over dam removal. And while some of these small dams may be taken down, there are studies underway on raising some large dams like Shasta, Friant, Terminus and Pine Flat for water supply and flood control purposes. Thus in the future, we may be holding more water in storage while blocking fewer streams.
You can see some of these key sites from your armchair when you tune into the Foundation’s new documentary Setting a Course for the California Bay-Delta. We need your help in getting your local public television station to air this 60-minute show. You can impress upon local programmers the importance of airing this show by calling the program director at your local station. You might mention your own interest in water issues and that the CALFED program is a monumental undertaking for the entire state. You could add that the public is going to be asked to pay for fixing the Delta and that too few people know where the Delta is, much less its crucial role in the state’s water picture. Call us for a list of station names and program directors.
If you want to see some of these water sites up close and personal, sign up for one – or both – of our upcoming water tours. The Eastern Sierra Watersheds Tour, September 23-25, offers you the chance to travel from Reno to Burbank along the eastern side of the Sierra Nevada with visits to Lake Tahoe, Mono Lake and the Owens Valley. On the Northern California Tour, October-7-9, you will see Shasta, Oroville and Red Bluff dams, as well as visit wetlands, a fish hatchery and other environmental restoration sites in the Sacramento Valley. Join us.
— Rita Schmidt Sudman (Executive Director)
In the News
Helping the Salmon
As CALFED staff wade through thousands of comments filed on the voluminous Bay-Delta report they released in March and debate builds among some stakeholders over the merits of building a peripheral canal, work continues on ecosystem enhancement projects throughout the Bay-Delta watershed.
One of the most dramatic projects is the restoration of Butte Creek, a tributary to the Sacramento River and one of three Sacramento Valley streams deemed critical to the survival of the spring-run chinook salmon. Already, two dams, Western Canal and Point Four, have been removed and two more, McPherrin and McGowan, are due for demolition within the next few months.
Although McPherrin Dam remains standing for now, a July event marking its scheduled destruction included an unveiling, of sorts, of what Butte Creek will look like once the dam is removed through use of a giant photo banner (see photo). The ceremony also featured a symbolic swing at the future as Interior Secretary Bruce Babbitt took a sledgehammer to the concrete structure that spans Butte Creek near Richvale.
It was a new ceremony for a new age, an age in which the destruction of a dam is as celebrated as is completion of a new offstream reservoir such as Los Vaqueros (see “In the News” in the May/June 1998 Western Water.) “These moments aren’t easy and I thought of that as I met with the generations of the McPherrin family who have invested their lives in the land,” Babbitt said at the event.
The secretary said his meeting with the family whose 1,700 acres of rice are served by McPherrin Dam revealed natural apprehension about a future where an inverted siphon managed by Western Canal Water District would supply water once provided by the dam. “It’s your place and always will be,” Babbitt assured the family, “and we’re here as a fresh generation to look for new ways we can accommodate mutual interests to the benefit of all.”
Lance Tennis, president of Western Canal’s board, said the Butte Creek siphon project is a “model of people coming together to solve a common problem for fish and water diverters.” Cost of the $9.4 million project was split three ways among Western Canal, the California Urban Water Agencies (CUWA) and the U.S. Fish and Wildlife Service. “We think it’s a great investment on the part of the district and these other agencies to improve salmon conservation in the creek, Tennis said.
Byron Buck, executive director of CUWA, praised the event and the dam’s pending demolition as a positive example of symbolism and substance and called upon others to move past the wasted energy of who’s to blame for environmental woes and get together to fix it.”
Calling it a win-win situation for everyone, CALFED Executive Director Lester Snow heralded the project’s innovation of cooperation that gives us faith in the CALFED program that we can restore environmental health and maintain economic viability.”
Project WET update
Did you catch the WET wave in 1998? There have been 25 workshops throughout California so far this year and several more still scheduled for this fall.
Project WET is a national K-12 interdisciplinary collection of 92 activities (532 busy pages!) about water education. These entertaining and educational activities bring a sense of fun to learning about the science of water molecules, management of water resources, the importance of water to the environment, uses of water, history of water use, aquatic environments, water and human health, water conservation and much, much more.
The Project WET Activity Guide was ranked by teachers as one of the top water education resources in the California Department of Education and Department of Water Resources “Water Education Compendium.” It is perfect for classroom teachers and nonformal educators.
The Project WET Gazette newsletter comes out three times a year and lists all times, places and contacts for the current workshops available. The newsletter also has tips on other kinds of water education. You can read the latest WET Gazette on our web page now!