Lapas attēli
PDF
ePub

C. OTHER OXYGENATES SHOULD BE STUDIED FOR HEALTH AND ENVIRONMENTAL

EFFECTS.

Federal law currently requires the use of oxygenates. Many have suggested repealing this requirement, in order to reduce oxygenate use throughout the country. This committee has legislation before it with substantially the same effect.

The United States Environmental Protection Agency warned, "It should not be inferred that the only oxygenate warranting attention is MTBE or, for that matter, that the issues identified here are necessarily unique to oxyfuels." 10 With new scientific data and practical experience, the U.S. EPA must carefully modify fuel regulations to protect the environment and human health.

As a policy matter, NRDC recommends resisting pleas that fuel constituents be mandated or that recipes of the fuel be defined by law. The risks of MTBE contamination should not be reduced in ways that simply increase other less-studied risks. To avoid a repetition of fuel contamination problems of recent years, full environmental and health impacts of alternatives to MTBE should be evaluated before they are used in gasoline.11

Even if the federal minimum requirement for oxygenates were repealed, it is likely that some use of oxygenates, whether ethanol, other alcohols 12 or ethers 13, would persist. The simple reason is that these substances boost octane in gasoline. The phase-out of lead, a dangerous neurotoxin, has required refiners to find alternatives for enhancing octane levels in gasoline.14 Without further environmental and health studies on the other oxygenates, it is impossible to know if substitution alternative oxygenates for MTBE will affect public health adversely.

1. Alternative Ethers May Not Reduce Groundwater Contamination.

Dr. John Froines and other University of California physicians and health scientists warn against assuming that MTBE is the only oxygenate posing environmental and health risks. "Introduction of these compounds [alternative ethers, including ETBE, TAME, and DIPE] as a substitute for MTBE is not advisable at this point in time given the paucity of data on their health effects." 15

MTBE has been extensively studied for both acute and chronic effects in animals and, to some extent, in humans. Some aquatic toxicity studies have been conducted for the alternative ethers, but essentially nothing is known about chronic health and environmental impacts of alternative ethers, including ETBE and TAME.16 "The information on the health effects and toxicology of the other substitutes, ETBE, TAME and DIPE is extremely limited." 17 What is know is that none of these oxygenates are without risk. All of the oxygenates can move swiftly through soil if spilled or leaked. There is no reason to believe other ethers would reduce toxicity relative to MTBE, and they, like MTBE, may make water unpalatable at extremely low concentrations.

2. Ethanol Use May Increase Air Toxics and Pose Additional Health Risks.

Ethanol is a familiar product, but it also poses health concerns. The UC Report on Health Effects states, "Use of ethanol would result in increased atmospheric con

10 Office of Research and Development, United States Environmental Protection Agency, Oxygenates in Water: Critical Information and Research Needs, EPA/600/R-98/048, December 1998, p. 5.

11 "Selection of an alternative to MTBE should not occur without adequate health effects and exposure assessment, and that is an important consideration in evaluating the potential efficacy of ethanol as an MTBE substitute." Froines, et al, "An Evaluation of the Scientific Peer-Reviewed Research and Literature on the Human Health Effects of MTBE, its Metabolites, Combustion Products and Substitute Compounds," Report to the Legislature of the State of California, Volume II, Human Health Effects, November 1998, p. 179.

12 Other alcohols which may be used as oxygenates include methanol and tertiary butanol (TBA).

13 Other ethers which may be used as oxygenates include ethyl tertiary butyl ether (ETBE), tertiary amyl methyl ether (TAME), tertiary amyl ethyl ether (TAEE), diisopropul ether (DIPE) and dimethyl ether (DME). Only the first two have been used in significant quantities to date. 14 The choices for octane enhancement have been properly limited by restrictions on toxic aromatics and neurotoxic metals such as lead and manganese compounds (e.g., MMT).

15 Froines, et al. Report to the Legislature of the State of California, Volume II, Human Health Effects, November 1998, pp. 179-180.

16 US EPA has required manufacturers to study the effects of chronic exposure to ETBE and TAME. The results will not be available for at least another year. See ORD, United States Environmental Protection Agency, Oxygenates in Water: Critical Information and Research Needs, EPA/600/R-98/048, December 1998, p. 24.

17 Froines, et al, "An Evaluation of the Scientific Peer-Reviewed Research and Literature on the Human Health Effects of MTBE, its Metabolites, Combustion Products and Substitute Compounds," Report to the Legislature of the State of California, Volume II, Human Health Effects, November 1998, p. 179.

centrations of acetaldehyde and peroxyacetylnitrate (PAN). Acetaldehyde has been listed as a Toxic Air Contaminant in California based on evidence of carcinogenicity and while PAN has not been tested for carcinogenicity, it is genotoxic [causes genetic damage] and produces respiratory and eye irritation and may produce lung damage." 18 In a separate section these scientists reiterate, "The formation of formaldehyde, acetaldehyde and PAN in the atmosphere [from ethanol use] are matters of considerable concern and represent one of our highest recommendations for future research." 19

Studies of high level exposures to ethanol (virtually all studies of ingestion rather than inhalation) demonstrate that ethanol increases a variety of adverse human health effects, ranging from developmental toxicity, central nervous system dysfunction, teratogenicity (birth defects), reproductive disorders and cancer 20. Pregnant women are generally advised to avoid ethanol exposure by avoiding alcoholic beverages, because chronic ingestion is known to cause fetal alcohol syndrome, a profound birth defect including major neurological dysfunction. Some data suggest developmental toxicity even at low doses.21 Today pregnant women can effectively avoid ethanol exposure. But if gasoline blends contain ethanol, pregnant women may find it impossible to avoid ethanol exposure through air when they refuel their vehicle. Today, no one knows if such exposures could be harmful to the developing fetus.

Before expanding the use of ethanol in gasoline, policy makers and the public should better understand the health impacts. Combustion products of ethanol include both formaldehyde and acetalydehyde, both known carcinogens. Likely subpopulations with special sensitivity to ethanol exposure include pregnant women and people with a specific genetic trait affecting their metabolism of ethanol.22 This genetic trait, a trait which a majority of Asian populations share, experience much higher blood levels of acetaldehyde and an increased potential for allergic reactions after ethanol exposure.23 Without further research, we are merely gambling that low-level, long-term ethanol exposure will not increase health hazards.

D. LEAKING FUEL TANKS ARE MAJOR SOURCES OF MTBE CONTAMINATION.

The experience in California is that the overwhelming source of MTBE in groundwater is leaking fuel tanks, and the predominant source of MTBE in surface water is recreational boating. But it is impossible to say that these factors are important or even significant in all regions of the country. Because every area has its own unique geology, and California's soils may be more permeable to petroleum spills and oxygenates than soils with greater organic content, the California experience may be instructive only for areas with similar, permeable soils and/or shallow groundwater supplies used for drinking water.

California has long had a huge number of underground storage tanks, most of which store petroleum products. An inventory in the 1984 revealed over 100,000 underground tanks. The State estimates it has now has over 50,000 operating underground storage tanks-about 6% of the nation's total. 24

California began efforts to regulate underground tanks in the early 1980s to protect the state's groundwater from solvents and fuels. Since then regulations have required tank owners to obtain permits, test tanks for leaks, and upgrade tanks with new containment and monitoring technology. In 1989 California also established a fund to help underground storage tank owners address leaking tanks 25 by imposing a mill fee on each gallon of petroleum tank owners put in to underground

18 Froines et al, "An Evaluation of the Scientific Peer-Reviewed Research and Literature on the Human Health Effects of MTBE, its Metabolites, Combustion Products and Substitute Compounds," Report to the Legislature of the State of California, Volume II, Human Health Effects, November 1998, p. xix.

19 Froines et al, 1998, p. 179.

20 Froines et al, "An Evaluation of the Scientific Peer-Reviewed Research and Literature on the Human Health Effects of MTBE, its Metabolites, Combustion Products and Substitute Compounds," Report to the Legislature of the State of California, Volume II, Human Health Effects, November 1998, pp. 144-153, 179., Health Effects Institute. The Potential Health Effects of Oxygenates Added to Gasoline, A Review of the Current Literature. A Special Report of the Institute's Oxygenates Evaluation Committee. April 1996.

21 Froines, op cit. p. 150-151.

22 Froines, op cit., p. 145-146.

23 Froines, op cit, p. 145-148.

24 Fogg et al, "Impacts of MTBE on Groundwater," Health and Environmental Assessment of MTBE, Report to the Legislature of the State of California, Volume IV: Ground & Surface Water, November 1998, p. 14.

25 Underground Storage Tank Cleanup Trust Fund Act, SB 299, Keene, 1989.

storage.26 The fee has been increased by subsequent legislation, but in light of the new demands on the fund for more costly clean-ups, further increases may be necessary.

As of June 1998, at least 32,779 sites in California were identified as leaking chemical compounds. 27 Ninety percent (90%)-more than twenty-nine thousand leaking California tanks-held petroleum products. In December of 1998 more stringent federal underground storage tanks requirements took effect, which required old and deteriorated tanks to be replaced. The State believes most of the worst leaking tanks were taken out of service. Nevertheless, of the thousands of corroded tanks which contaminated soil nearby, only a small percentage were actively treated to remove contaminants. In most sites involving petroleum products, the chosen remedy was "natural attenuation" essentially waiting for soil microorganisms to biodegrade the harmful compounds.28

As of 1998, 3,486 groundwater sites have been identified with MTBE contamination.29 Not surprisingly, "MTBE impacts to drinking water wells were similar to benzene impacts given current regulatory action levels." 30 Fortunately, a small percentage of these sites involve high concentrations.

More leaks may threaten ground water, since many "closed sites"-leaking sites no longer under investigation-were not tested for MTBE and were not actively remediated.31 Leaking underground fuel storage tanks are believed to be the primary source of acute groundwater contamination of MTBE (levels above 20ug/1) in California.32 Experts say old tank removal may reduce the rate of tank failures in the near future.

But if gasoline contains oxygenates, future gasoline tank leaks involving MTBE appear inevitable. Even new tanks will eventually fail through material aging, operator error, and accident. There are also some reports of MTBE + gasoline groundwater contamination from pipeline leaks, above ground fuel tanks failures, and gasoline tanker truck accidents, and these will continue as long as oxygenate use continues.33

E. CALIFORNIA, AND THE NATION, MUST SWIFTLY ADDRESS GASOLINE CONTAMINATION SITES.

Chemical properties of oxygenates tend to make gasoline leaks and spills more problematic when they include oxygenates. Ethers and alcohols are highly water soluble and only weakly adsorbed by soil, so these oxygenates move through soil essentially as rapidly as groundwater once they leak or spill. Ethers are resistant to decontamination by soil microorganisms. Alcohols, however, are preferentially consumed by soil microbes relative to conventional gasoline compounds. The consequence, in either case, may be a more persistent, rapidly migrating plume of contaminants, requiring more complex intervention.

Probably at least as problematic as rapid soil migration is the very low odor and taste threshold of ethers, which make water with even minute (parts per billion)

26 Wiley, Kip, Senate Office of Research, California Legislature, "Clean Air vs. Clean Water Does California Need MTBE?," February 1998.

27 Fogg, et al, "Impacts of MTBE on Groundwater," Health and Environmental Assessment of MTBE, Report to the Legislature of the State of California, Volume IV: Ground & Surface Water, November 1998, p. 6.

28 Fogg, et al, "Impacts of MTBE on Groundwater," Health and Environmental Assessment of MTBE, Report to the Legislature of the State of California, Volume IV: Ground & Surface Water, November 1998, p. 57.

29 Fogg, et al, "Impacts of MTBE on Groundwater," Health and Environmental Assessment of MTBE, Report to the Legislature of the State of California, Volume IV: Ground & Surface Water, November 1998, p. 23.

30 Happel et al, Lawrence Livermore National Laboratory, An Evaluation of MTBE Impacts to California Groundwater Resources, report submitted to the California State Water Resources Control Board Underground Storage Tank Program, June 11, 1998, p. 32. Also see Keller et al, stating that the benzene, toluene, xylene and ethylbenzene components of gasoline were found at approximately 50% of leaking fuel sites and MTBE was found at about 49%, "Cost and Performance Evaluation for MTBE-contaminated Water," Health and Environmental Assessment of MTBE, Report to the Legislature of the State of California, Volume V, November 1998, p.49.

31 Fogg et al, in "Impacts of MTBE on Groundwater," Health and Environmental Assessment of MTBE, Report to the Legislature of the State of California, Volume IV: Ground & Surface Water, November 1998, p. 28, state that 169 of 186 closed gasoline contaminated sites in Los Angeles had detectable concentrations of MTBE, as did 38 of 65 closed gasoline sites in the Central Valley.

32 Fogg, op cit., p. 7.

33 Fogg, op cit., pp. 31-34.

quantities of MTBE or other ethers objectionable to most consumers. 34 The positive side of this characteristic is that people will not be inadvertently exposed to drinking water contaminated with even extremely small levels of MTBE contaminationthe foul taste will warn anyone away from drinking such water. But this ability to detect trace contamination increases pressure on water agencies concerned about providing acceptable water and worried about treatment costs of reducing any contamination to extremely low levels.

Cleanup of gasoline spills including any oxygenate must be designed to respond to the specific constituents and conditions at the site. Oxygenates may increase the cost of cleanup, with estimates of MTBE clean-up costs vary from 25% to 80% higher than comparable gasoline spills without oxygenates.35,36 MTBE and other ethers are persistent in the soil as compared to benzene and other typical gasoline constituents, and recent evidence about the effectiveness of biodegradation is equivocal.37

Early fears that MTBE-contaminated sites could not be remediated now appear excessively pessimistic.38 However, it appears likely that many MTBE-contaminated sites will persist and migrate with ground water unless active intervention occurs. Although prevention of gasoline spills and leaks must be a national priority, once leaks are identified, remedial action should be swift and complete.

F. CONGRESS CAN HELP REDUCE CONTAMINATION BY ALLOWING REDUCED OXYGENATE USE.

In the last Congress and again in this Congress, Representative Brian Bilbray of San Diego and California Senator Dianne Feinstein introduced bills to allow states to reduce or eliminate oxygenates under certain conditions providing the fuel achieves equivalent or greater emission reductions. This legislation, or legislation which simply eliminates the requirement for minimum percentage of oxygenate in fuels, would be a sound first step at addressing contamination from gasoline spills containing oxygenates, if it were revised to include clear requirements assuring that the air quality benefits of the oxygenate mandate are not lost. Of course, the legislation should also promote more effective gasoline containment and better enforcement of current storage or cleanup requirements. It is however, not realistic to expect any legislative action to eliminate water contamination problems from past or future spills or leaks.

While supporting the goal of minimization of oxygenate use, NRDC has been reluctant to encourage any amendments to the Clean Air Act, and will resist any broad opening of this landmark statute.. If the Bilbray / Feinstein bills, or similar bills designed only to remove the required oxygenate minimum while preserving RFG air quality benefits, can be enacted, we believe this would begin to remedy a serious environmental threat, especially for parts of the country with shallow surface water or highly permeable soils. The problem posed by gasoline spills should trigger further examination and strengthening of federal authority to protect and clean water supplies contaminated with petroleum products. But NRDC will continue to vigorously oppose opening the Clean Air Act beyond this narrow issue.

H. NRDC'S RECOMMENDATIONS FOR ADDRESSING AIR AND WATER QUALITY CONCERNS ARISING FROM OXYGENATE USE:

1. The Federal Reformulated Gasoline Program must preserve all air quality benefits, including the air toxics, ozone precursor, and aromatic reductions, which were required by the Clean Air Act. ÉPA should ensure that any future changes

34 Office of Research and Development, United States Environmental Protection Agency, Oxygenates in Water: Critical Information and Research Needs, EPA/600/R-98/048, December 1998, p. 20. EPA cites recent studies suggesting that taste and odor thresholds may be even lower for ETBE and TAME than for MTBE.

35 Kavanaugh, M., Malcolm Pirnie, Inc, "Brief Review of MTBE Fate, Transport, and Remediation," presentation of February 4, 1999, p. 10-11, estimates a 25% increase in treatment costs. 36 Keller, et al, Cost and Performance Evaluation of Treatment Technologies for MTBE-Contaminated Water, Health and Environmental Assessment of MTBE, Report to the Legislature of the State of California, Volume III, November 1998, p. 30 offer an estimated cost increase for treatment of MTBE-contaminated water of from 40% to 80% over treatment of water contaminated with conventional, non-oxygenated gasoline.

37 Office of Research and Development, United States Environmental Protection Agency, Oxygenates in Water: Critical Information and Research Needs, EPA/600/R-98/048, December 1998, p. 10-12

38 Office of Research and Development, United States Environmental Protection Agency, Oxygenates in Water: Critical Information and Research Needs, EPA/600/R-98/048, December 1998, pp. 30-37. Also see Kavanaugh, Malcolm Pirnie, Inc. "Review of the UC SB521 Study: Water Treatment and Remediation Costs," December 1998.

in RFG (such as changing or reducing oxygenates) do not increase levels of toxics or ozone precursors either in areas using RFG or in the rest of the country using conventional gasoline.

2. Congress can reduce the risk to water supplies from petroleum spills by elimination of the minimum oxygen content requirement in federal reformulated gasoline coupled with clear requirements to fully preserve RFG air quality benefits, including those benefits that flow from the existing oxygenate mandate.

3. Remediation should occur swiftly at sites where gasoline has spilled or leaked Passively awaiting microbiological degradation of gasoline contaminants should not be assumed appropriate for fuel spills or leaks, particularly those threatening water resources. Costs for the cleanup should be recovered from parties responsible for the spills or leaks.

4. Protection of surface water depends on careful regulation of boating (and restrictions on the use of jet skis or other inefficient 2-stroke gasoline engines). Restrictions on numbers of boats, engine types and fueling methods can help to reduce water contamination, and appear necessary regardless of future oxygenate policy.

5. The country needs improved fuel storage tank regulations, including improving siting and monitoring restrictions. Furthermore, enforcement must be strict to ensure recovery of cleanup costs from those responsible for spilling or improperly storing fuel.

SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
DIAMOND BAR, CA

The Honorable BRIAN BILBRAY

U.S. House of Representatives

Longworth House Office Building Suite 1530

Independence and New Jersey Avenue SE

May 4, 1999

Washington, DC 20515

H.R. 11-California Reformulated Gas Rules

I am pleased to inform you that the South Coast Air Quality Management District (AQMD) supports your H.R. 11, which would amend the Clean Air Act to allow California's cleaner-burning gasoline regulations to apply in California, in lieu of existing federal regulations, when California regulations achieve equivalent or greater reductions in emissions of ozone-forming compounds and toxic contaminants.

California has some of the worst air pollution in the nation. Since the introduction of reformulated gasoline in 1996, the South Coast Air Basin has experienced some of its best air quality in years. However, when the U.S. EPA was directed to adopt a federal reformulated gas program, only specified properties were mandated for use. This limited flexibility among refiners in producing cleaner-burning gasoline. H.R. 11, along with California actions, provides refiners much greater flexibility in the formulation of cleaner-burning gasoline.

Reformulated gasoline is a critical measure in California's State Implementation Plan. With this measure we can look forward to increasing the health of our residents in California and the South Coast Air Basin. We appreciate your efforts in this area and fully support H.R. 11. Sincerely,

BARRY R. WALLERSTEIN, D.ENV.

Executive Officer

CALIFORNIA ENVIRONMENTAL PROTECTION AGENCY

AIR RESOURCES BOARD Sacramento, CA 95812-2815 July 31, 1996

The HONORABLE THOMAS BLILEY
Chairman, House Committee on Commerce
U.S. House of Representatives

Washington, DC 20515

DEAR MR. CHAIRMAN: I am pleased to express the support of the California Air Resources Board (ARB) for H.R. 3518, which was introduced by Congressman Brian Bilbray on May 23, 1996. Under this bill, California cleaner burning gasoline regulations will apply in California in lieu of existing federal reformulated gasoline regulations as long as the California regulations achieve equivalent or greater reductions

« iepriekšējāTurpināt »