Federal Government's Knowledge of MTBE’s Risks
to Groundwater When The Government Required Its UseEPA's Knowledge of MTBE's Risks of Groundwater Contamination. A summary of the information on this page: Plaintiffs’ Claims that Industry Concealed from the Federal Government MTBE’s Risks to Groundwater are Incorrect.
Plaintiffs in MTBE litigation claim that EPA and the Congress authorized the use of MTBE as a gasoline oxygenate under the Clean Air Act Amendments of 1990 because oil refiners hid from government officials knowledge about the risk that MTBE in gasoline could leak or spill and compromise drinking water supplies. Examination of EPA’s pre-1990 rulemaking in which it required manufacturers of MTBE to conduct studies on MTBE’s health effects contradicts such claims. Plaintiffs in MTBE litigation claim that EPA and the Congress authorized the use of MTBE as a gasoline oxygenate under the Clean Air Act Amendments of 1990 because oil refiners hid from government officials knowledge about the risk that MTBE in gasoline could leak or spill and compromise drinking water supplies. Examination of EPA’s pre-1990 rulemaking in which it required manufacturers of MTBE to conduct studies on MTBE’s health effects contradicts such claims. EPA Investigated and Addressed MTBE Groundwater Contamination Risks in the Late 1980s. Section 4 of the Toxic Substances Control Act (TSCA) authorizes EPA to conduct assessments of the potential health or environmental effects of chemicals. EPA can require manufacturers of a chemical to undertake further testing to develop safety and environmental data when (1) the chemical may present an unreasonable risk of injury, or (2) the chemical has the potential for substantial environmental or human exposure. This process was undertaken for MTBE from 1986-88. During the TSCA Process, EPA Obtained Extensive Knowledge of MTBE’s Risks to Groundwater.
In November 1986, the Interagency Testing Committee (ITC), which is tasked with making recommendations to the EPA Administrator regarding whether chemicals should be subject to environmental or health effects testing, recommended MTBE for testing. Among the reasons it cited for supporting additional testing was MTBE’s persistence in the environment: Persistence. Nearly all of the MTBE released to the environment will partition to the atmosphere where it will be degraded by hydroxy radicals, with an atmospheric half-life of about 3.5 days. The products of this oxidation are likely to include t-butyl formate (major product), acetone, and methyl radical (Ref. 7, Cox and Goldstone, 1981). Persistence in ground water following spills is unknown, but it may persist for long periods if volatilization is prevented, since MTBE is not likely to be readily biodegraded or otherwise transformed in ground water.
Nineteenth Report of the Interagency Testing Committee to the Administrator, 51 Fed. Reg. 41417 (Nov. 14, 1986)
The Public Record in the EPA rulemaking clearly reveals that EPA was highly knowledgeable about the solubility, taste, odor and biodegradability characteristics of MTBE, and the potential for groundwater contamination.
The MTBE rulemaking was managed by the Test Rules Development Branch (TRDB) of the Office of Toxic Substances (OTS) of EPA. TRDB took up the issue of groundwater contamination so that it could design a test rule that appropriately addressed that risk as well as MTBE vapor inhalation concerns.
EPA Officials Learned in 1986 of MTBE Contamination of Groundwater in Maine and North Carolina.
In late 1986, TRDB officials spoke with officials from North Carolina and Maine about MTBE groundwater contamination in their states. The North Carolina official noted that North Carolina was addressing approximately 300 gasoline leaks and that MTBE began to be identified in water samples near such leaks about eight months earlier. Officials from the Maine Department of Environmental Protection (Marcel Moreau and Peter Garrett) described their understanding of MTBE’s fate and transport characteristics in groundwater, including MTBE’s relatively high solubility in water compared to other components of gasoline and its failure to adhere to soil, resulting in its tendency to migrate relatively rapidly through groundwater at the head of the gasoline plume. Moreau and Garrett shared with TRDB a copy of their November 1986 paper, MTBE as a Groundwater Contaminant. This paper was presented at the National Well Water Association / American Petroleum Institute Conference on Petroleum Hydrocarbons and Organic Chemicals in Groundwater – Prevention, Detection, and Restoration, November 12-14, 1986, Houston, Texas. Another Maine official reported that MTBE had been detected in over 50% of wells tested near gasoline spill sites.
EPA Raises Concerns about Groundwater Contamination Risks at a Public Meeting in December 1986.
At a December 17, 1986 meeting, TRDB officials emphasized that, in addition to the concerns raised in the ITC’s MTBE report, “[a]n additional concern brought out by TRDB research was the contamination of ground water supplies by MTBE.”
EPA Obtains Additional Information about Groundwater Contamination from Around the Country.
Following the meeting, EPA issued a “Request for Exposure Data: MTBE in Ground Water” in December 1986. The notice explained that a TSCA § 4 rulemaking for MTBE was underway, that MTBE is primarily used as a gasoline additive, and that OTS’ “current concern is the appearance of MTBE in private wells and ground water. Because gasoline is stored in underground tanks and many of these tanks leak, MTBE has been identified as a ground water contaminant in several states. The chemical properties of MTBE make it more soluble in water than other components of gasoline.”
This notice went to regional EPA offices and state environmental protection and/or water agencies. In response, several states contacted EPA to report incidences of MTBE groundwater contamination, including New Mexico, New Jersey, Pennsylvania, Massachusetts, Connecticut, and New Hampshire, as well as Maine.
EPA's Publications and Internal Documents Discuss MTBE’s Properties and Demonstrated Risks to Groundwater.
In February 1987, EPA’s Test Rules Branch issued a “Technical Support Document” for MTBE. The document referenced MTBE releases to groundwater from leaking USTs, and noted that a 50-state study indicated 12,444 releases of material from USTs between 1984-86. An EPA survey found that there were about 796,000 non-farm USTs in the US, and that about 35% did not pass tightness tests. The document identifies virtually every salient characteristic of MTBE that plaintiffs in MTBE litigation claim that defendants “concealed” from regulators: “Since MTBE appears to be relatively mobile in soils, leachant water is expected to transport MTBE into deeper soil horizons more rapidly than the more hydrophobic components of gasolines.” “MTBE does not contain any moieties that would indicate the potential for soil covalent binding.” “Ethers are sometimes resistant to biodegradation.” A leak in Maine “was detected by the odor of the contaminated water.” “Humans can detect MTBE concentrations of 20-50 ppb in water.” In an April 6, 1987 memo, a TRDB official wrote, “Concern about MTBE in drinking water surfaced after the ITC report . . . this problem could rapidly mushroom due to leaking underground storage tanks at service stations." "The tendency for MTBE to separate from the gasoline mixture into ground water could lead to wide spread drinking water contamination.'' In an August 7, 1987 memo, an EPA official wrote, “[T]he relatively water soluble nature (40,000 to 51,000 mg/L) of MTBE results in rapid movement of this compound into ground water, ahead of other gasoline components. Because production of MTBE has increased over 140% between 1982 and 1985, analyses for and reports of this compound in ground water are a recent phenomenon. We know of reports of MTBE contamination in Maine, New Jersey, New Mexico, North Carolina and Connecticut.” EPA’s Office of Underground Storage Tanks released a publication in April 1988 called “Cleanup of Releases from Petroleum USTs: Selected Technologies.” The publication, which was a handbook for cleanup engineers of technologies available for removing gasoline and its components from soil and groundwater, stated: MTBE is being more widely used as an octane enhancing additive to gasoline, especially because tetraethyl lead is being phased out. Although MTBE has been produced commercially only since 1979, it is now among the top 50 chemicals produced in the United States. MTBE is extremely soluble in water; about 24 times more soluble than benzene (43,000 mg/L vs. 1,780 mg/L). Because of its high solubility, MTBE is easily transported by groundwater away from a spill site and will often have a larger plume than gasoline components such as benzene... Commenting on remediation system technology, it stated that MTBE “might appear in the effluent [from carbon water treatment systems even before benzene due to [its] very low adsorption capacities.” Some highly soluble organic compounds found in gasoline, such as MTBE and DIPE, have very high carbon usage rates. If these compounds are found in high concentrations in the influent water, frequent carbon replacement will be required, thus making carbon adsorption considerably more expensive.”
Finally, the document contained a “Case Study” of an MTBE contamination incident that took place in Rockaway Township, New Jersey in 1980.
The EPA Knew About and Acted Upon Groundwater Contamination Concerns in the MTBE Testing Consent Order.
In response to information it obtained during the MTBE TSCA review process regarding MTBE’s groundwater contamination risks, EPA promptly included this issue on its agenda and addressed it in the course of considering whether to require further health effects testing for MTBE. Indeed, the resulting consent order required manufacturers to conduct testing on the health effects of MTBE for the express purpose of “better characteriz[ing] the potential of MTBE to cause adverse health effects in persons exposed to: (1) MTBE vapor during the transfer of MTBE or MTBE-containing gasoline, (2) MTBE vapor via contaminated groundwater, or (3) MTBE orally via consumption of contaminated water.”
The level of EPA's knowledge regarding MTBE’s potential to contaminate groundwater is set forth in the Testing Consent Order published in Federal Register (53 Fed. Reg. 10391) (1988):
MTBE vapor exposure via gasoline was the major concern expressed in the 19th ITC report. However EPA has an additional concern about MTBE contamination of ground water. Although only a few cases of ground water contamination are currently documented, the rapid growth in production, transport, and use of MTBE will probably contribute to an increase in incidents of contamination. The relatively recent appearance of MTBE in the market place has hampered the documentation of ground water contamination because laboratory analyses do not typically screen for this compound and gasoline is composed of more than 50 different hydrocarbon compounds. MTBE is relatively water soluble (40,000 to 51,260 mg/L) compared to other gasoline components. This solubility, coupled with the fact that an estimated 35 percent of the approximately 638,000 non-farm underground motor fuel tanks would not pass the EPA tightness test, indicates the potential ground water contamination problem. The largest identified population affected by MTBE-contaminated water was Rockaway Township in New Jersey, population 20,000. The level of MTBE contamination in the township wells ranged from 25 to 40 ppb and required aeration treatment before delivery to the township’s residents. EPA has received requests for information on MTBE as a result of other well water contamination reports in New Jersey and New Hampshire. A leaking underground storage tank in a rural area of Maine has contaminated household wells in the vicinity with MTBE concentrations as high as 690 ppb. Maine and New Jersey have set a maximum contaminant level of 50 ppb for MTBE.
In 1988, the EPA Added MTBE to the “Drinking Water Priority List.”
At that time the EPA pointed out that over a third of gasoline storage tanks nationwide “would not pass the EPA tightness test” causing the EPA to conclude “the rapid growth in production, transport, and use of MTBE will probably contribute to an increase in incidents of contamination.” EPA continued to support use of MTBE well into the 1990s.
In 1996, EPA put together an “Issue Paper” to respond to press reports of MTBE detections in drinking water supplies. In that Issue Paper, EPA concluded: “EPA supports the continuation of the use of oxygenates, such as MTBE, in fuels under such programs as the reformulated gasoline program. EPA believes that there are significant air quality and public health benefits as the result of the use of oxygenated fuels.” Today, use of MTBE in gasoline is still permitted, despite public disclosure of all the risks plaintiffs in litigation allege were previously concealed. Congress and EPA Knowledge Regarding Use of MTBE as an Oxygenate
The Clean Air Act Amendments of 1990 established two programs, the Wintertime Oxyfuel Program (effective November 1992) and the Reformulated Gasoline Program (RFG) (effective January 1995), which required refiners to add oxygenates to their gasoline. The Clean Air Act Amendments of 1990 established two programs, the Wintertime Oxyfuel Program (effective November 1992) and the Reformulated Gasoline Program (RFG) (effective January 1995), which required refiners to add oxygenates to their gasoline. The legislative record from the CAAA demonstrates Congress’s (and EPA’s) recognition that MTBE would be the most widely used oxygenate in meeting the CAAA oxygenate mandates, and further demonstrates that MTBE usage was seen as a positive factor for the environment and energy security. For example: “EPA predicts that the amendment will be met almost exclusively by MTBE, a methanol derivative,” 136 Cong. Rec. S 6383, 6384 (1990) (remarks of Sen. Daschle); “The MTBE market is expected to expand by more than 20 percent every year for the next five years” as a result of the CAA amendments, and “…. MTBE is going to be a major, if not ‘the’ major beneficiary of the [oxygenate] standard.” 136 Cong. Rec. S. 2280, 2289 (1990) (remarks of Sen. Daschle); The RFG Program “will encourage the use of oxygen-containing additives like ethanol and MTBE”, 136 Cong. Rec. S 16954 (1990) (remarks of Sen. Chafee); “The requirements for reformulated gasoline will also encourage the use of oxygen-containing additives like ethanol and MTBE,” 136 Cong. Rec. S 17514 (remarks of Sen. Heinz); MTBE is “good for energy security and our balance of trade, as well as the environment” because RFG with a 15% MTBE content required 15% less gasoline, 136 Cong. Rec. S 3513 (1990) (remarks of Sen. Daschle).
In fact, Congress carefully drafted its fuel content requirements to ensure that refiners would be able to use MTBE to comply with the Oxy-Fuel and RFG mandates. For example, at one point in the legislative process the proposed oxygenate level was set at 3.1% – which could not have been met by using MTBE. In the final legislation, Congress reduced that level to 2.7% specifically to promote the use of MTBE: The level of 2.7 percent was chosen in part to provide more even opportunities for competition between the two major oxygenates, methyl tertiary butyl ether (or MTBE), and ethyl alcohol (or ethanol). The [EPA] Administrator may not discriminate among these different oxygenates, and should encourage fair competition among them.
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