CLEAN AIR AMD CLEAN The Report of the Blue Ribboh Oxygenates in Panel on Gasoline in Panel to review the us( The Panel was appointee rntaf Protection Agency'! was originally establishec I the requirements of thg APP. 8 9 (a.

led technical, analytical pport for this report.

eptem ber 1999 ... ...* >. A ...... U. ....................... _ .... a. ........ , . I 1 I CHAPTER 1 . EXECUTIVE SUMMARY .................................... '.

CHAPTER 2 . ISSUE SUMMARIES .................................................... Water contamination ................................................... A . TABLE OF CONTENTS .......... 1 15 17 Page IV . Behavior ....................................................... V . AppendixA ........................................................... B . AirQualityBenefits .................................................... I . Introduction ................................................... I1 . Federal RFG Program: Requirements and Benefits ...................... I11 . The Impact on RFG if Oxygenates are Removed ........................ IV . Other Air Quality Considerations for Oxygenates ........... : V . Appendix B ............................................... '. C . Prevention. Treatment. and Remediation ................................... I . Introduction ..................................................... I1 . Sources and Trends of Water Quality Impacts .......................... I11 . Release Prevention and Detection .................................. IV . Underground Storage Tanks ........................... .I .

V . Protection of Drinking Water Sources and Water Quality Managerient VI . Treatment of Impacted Drinking Water ................... '

VI1 . Remediation .................................................... Fuel Supply and Cost .................................................... I . Introduction ..................................................... I1 . Industry Overview ................................... ; Impact of Fuel Requirement Changes on Supply ............ ' Cost Impacts of Changing Fuel Reformulations ........................ AppendixD .............................................. * ~ 1  *

Comparing the Fuel Additives ................................. ;. I . Introduction ..................................................... MTBE ......................................................... I1 . 111 . Ethanol ........................................... .I '

IV . Other Ethers .................................................... V . Other Alternatives ................................... ,

AppendixE ........................................................... Drinking Water Standards ............................. .,.

Wintertime Oxfiel Program ........................... '.

D .

I I11 . IV .

E .

. 21 .......... 22 25 27 27 27 31 ........... 35 .......... 38 .......... 42 45 45 45 50 .......... 52 ..... 53 ........... 55 57 67 67 ........... 68 ........... 72 75 * . . * * * 79 .......... 81 81 81 84 86 ........... 86 88 ...........

CHAPTER 4 . DISSENTING OPINIONS ................................................

~

LIST OF PANEL MEMBERS AND PARTICIPANTS ........................... '

REFERENCES .......................................................... ' 99 .......... 107 .......... 113 TABLE OF CONTENTS (continued)

GLOSSARY OF TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . .! .

... Page ........... 121 CHAPTER 1. EXECUTIVE SUMMARY , I The Federal Reformulated Gasoline Program (RFG) established in the Clean Air Act Amendments of 1990, and implemented in 1995, has provided substantial reductions in the emissions of a number of air pollutants from motor vehicles, most notably volatile organic compounds (precursors of ozone), carbon monoxide, and mobile source air toxics (benzene, 1 ,3 butadieneY and others), in most cases resulting in emissions reductions that exceed those required by law. To address its unique air pollution challenges, California has adopted similar, but more stringent requirements for California RFG. In addition, areas in both California and elsewhere in the nation that have not attained the National Ambient Air Quality Standard for carbon monoxide are required in the Act to implement the Wintertime Oxyfuel program.

The Clean Air Act requires that RFG contain 2 percent oxygen by weight. Over 85 percent of RFG contains the oxygenate methyl tertiary butyl ether (MTBE) and approximately 8 percent cdntains ethanol  a domestic fuel blending stock made from grain and potentially from recycled biomass waste. The Act requires Wintertime Oxyfuel to contain 2.7 percent oxygen by weight.

There is disagreement about the precise role of oxygenates in attaining the RFG air quality benefits, although there is evidence from the existing program that increased use of oxygenates results in reduced carbon monoxide emissions, and it appears that additives contribute to reductions in aromatics in fuels and related air benefits. It is possible to formulate gasoline without oxygenates that can attain similar air toxics reductions, but it is less certain that given current Federal RIG requirements ail fuel blends created without oxygenates could maintain the benefits provided today by oxygenated R$ G.

At the same time, the use of MTBE in the program has resulted in growing detections of AdTBE in drinking water, with between 5 percent and 10 percent of community drinking water supplies in high oxygenate use areas' showing at least detectable amounts of MTBE. The great majority of these detections to date have been well below IeveIs of public health concern, with approximately one percent rising to levels above 20 parts per billion (ppb). Detections at lower levels have, however, raised consumer taste and odor concerns that have caused water suppliers to stop using some water supplies and to incur costs of treatment and remediation. Private wells have also been contaminated, and these wells are less protected than public drinking water supplies and not monitored for chemical contamination. There is also evidence of contamination of surface waters, particularly during summer boating seasons.

The major source of groundwater contamination appears to be releases from underground gasoline storage systems. These systems have been upgraded over the last decade, likely resulting in reduced risk of leaks. However, approximately 20 percent of the storage systems have not yet been upgraded, and there continue to be reports of releases from some upgraded systems, due to inadequate design, installation, maintenance, and/ or operation. In addition, many fuel storage systems (e. g. farms, small above ground tanks) are not currently regulated by the US. Environmental Protection Agency. Beyond groundwater contamination from underground storage tank (UST) sources, the other major sources of water contamination appear to be small and large gasoline spills to ground and surface waters, and recreational water craft  particularly those with older motors  releasing unburned fuel to surface waters.

' Areas using RFG (2% by weight oxygen) and/ or Oxyfuel( 2.7% by weight Oxygen) I 1 The Blue Ribbon Panel In response to the growing concerns from State and local officials and the public, U. S. EPA Administrator Carol M. Browner appointed a Blue Ribbon Panel in November 1998, to investigate the air quality benefits and water quality concerns associated with oxygenates in gasoline, and to provide independent advice and recommendations on ways to maintain air quality while protecting water quality.

The Panel members consisted of leading experts from the public health and scientific communities, automotive bels industry, water utilities, and local and State governments. The Panel was charged to: (1) examine the role of oxygenates in meeting the nation's goal of clean air; (2) evaluate each product's efficiency in providing clean air benefits and the existence of alternatives; (3) assess the behavior of oxygenates in the environment; (4) review any known health effects; and (5) compare the cost of production and use and each product's avaiIability  both at present and in the future. Further, the Panel studied the causes of ground water and drinking water contamination from motor vehicle fuels, and explored prevention and cleanup technologies for water and soil. The Panel was established under EPA's Federal Advisory Committee Act's Clean Air Act Advisory Committee, a policy committee established to advise the U. S. EPA on issues related to implementing the CAAA of 1990. It met six times from January  June, 1999, heard presentations in Washington, the Northeast, and California about the benefits and concerns related to RFG and the oxygenates; gathered the best available information on the program and its effects; identified key data gaps; and evaluated a series of alternative recommendations based on their effects on:

 air quality  water quality  stability of fuel supply and cost This report consists of five issue summaries: water contamination; air quality benefits; prevention; treatment and remediation; fuel supply and cost; and comparing the fuel additives. In addition, this report contains the findings and recommendations of the Panel, dissenting opinions, list of Panel members, references, and glossary of terms.

The Findings and Recommendations of the Blue Ribbon Panel Based on its review of the issues, the Panel made the following overall findings: ,

* The distribution, use, and combustion of gasoline poses risks to our environment and RFG provides considerable air quality improvements and benefits for millions of US public health.

8 citizens. I  8 The use of MTBE has raised the issue of the effects of both MTBE alone and MTBE in gasoline. This Panel was not constituted to perform an independent comprehensive health assessment and has chosen to rely on recent reports by a number of state, national, and international health agencies. What seems clear, however, is that MTBE, due to its persistence and mobility in water, is more likely to contaminate ground and surface water than the other components of gasoline.

2 e MTBE has been found in a number of water supplies nationwide, primarily causing consumer odor and taste concerns that have led water suppliers to reduce use of those supplies. Incidents of MTBE in drinking water supplies at levels well above EPA and state guidelines and standards have occurred, but are rare. The Panel believes that the occurrence of MTBE in drinking water supplies can and should be substantially reduced.

e MTBE is currently an integral component of the U. S. gasoline supply both in terms of . volume and octane. As such, changes in its use, with the attendant capital construction and infrastructure modifications, must be implemented with sufficient time, certainty, and flexibility to maintain the stability of both the complex U. S. fuel supply system and gasoline prices.

The following recommendations are intended to be implemented as a SingZepackage of actions designed to simultaneously maintain air quality benefits while enhancing water quality protection and assuring a stable fuel supply at reasonable cost. The majority of these recommendations could be implemented by federal and state environmental agencies without further legislative action, and we would urge their rapid implementation. We would, as weI1, urge all parties to work with Congress to implement those of our recommendations that require legislative action.

Recommendations to Enhance Water Protection Based on its review of the existing federal, state and local programs to protect, treat, and remediate water supplies, the Blue Ribbon Panel makes the following recommendations to enhance, accelerate, and expand existing programs to improve protection of drinking water supplies from contamination.

Prevention 1. EPA, working with the states, should take the following actions to enhance significantly the Federal and State Underground Storage Tank programs:

a. Accelerate enforcement of the replacement of existing tank systems to conform with the federally required December 22, 1998 deadline for upgrade, including, at a minimum, moving to have all states prohibit fuel deliveries to non upgraded tanks, and adding enforcement and compliance resources to ensure prompt enforcement action, especially in areas using RFG and Wintertime Oxyfuel.

b. Evaluate the field performance of current system design requirements and technology and, based on that evaluation, improve system requirements to minimize leaks/ releases, particularly in vulnerable areas (see recommendations on Wellhead Protection Program in 2. below).

Strengthen release detection requirements to enhance early detection, particularly in vulnerable areas, and to ensure rapid repair and remediation.  C.

d. Require monitoring and reporting of MTBE and other ethers in groundwater at all UST release sites.

3 2. e. Encourage states to require that the proximity to drinking water supplies, and the potential to impact those supplies, be considered in land use planning and permitting decisions for siting of new UST facilities and petroleum pipelines.

f. Implement and/ or expand programs to train and license UST system installers and maintenance personnel.

g. Work with Congress to examine and, if needed, expand the universe of regulated tanks to include underground and aboveground fuel storage systems that are not currently regulated yet pose substantial risk to drinking water supplies.

EPA should work with its state and local water supply partners to enhance implementation of the Federal and State Safe Drinking Water Act programs to:

a. Accelerate, particularly in those areas where RFG or Oxygenated Fuel is used, the assessments of drinking water source protection areas required in Section 1453 of the Safe Drinking Water Act, as amended in 1996.

b. Coordinate the Source Water Assessment program in each state with federal and state Underground Storage Tank Programs using geographic information and other advanced data systems to determine the location of drinking water sources and to identie UST sites within source protection zones.

C. Accelerate currently planned implementation of testing for and reporting of MTBE in public drinking water supplies to occur before 2001.

d. Increase ongoing federal, state, and local efforts in Welihead Protection Areas including:

I  enhanced permitting, design, and system installation requirements for USTs and pipelines in these areas; strengthened efforts to ensure that non operating USTs ate properly closed; enhanced UST release prevention and detection; and improved inventory management of fuels.

3. EPA should work with states and localities to enhance their efforts to protect lakes and reservoirs that serve as drinking water supplies by restricting use of recreational water craft, particularly those with older motors.

4. EPA should work with other federal agencies, the states, and private sector partners to implement expanded programs to protect private well users, including, but not limited to:

a. A nationwide assessment of the incidence of contamination of private wells by components of gasoline as well as by other common contaminants in shallow groundwater;

4 b. Broad based outreach and public education programs for owners and users of private wells on preventing, detecting, and treating contamination; and C. Programs to encourage and facilitate regular water quality testing of private wells.

5. Implement, through public private partnerships, expanded Public Education programs at the federal, state, and local levels on the proper handling and disposal of gasoline.

6 . Develop and implement an integrated field research program into the groundwater behavior of gasoline and oxygenates, including:

a. Identifying and initiating research at a population of UST release sites and nearby drinking water supplies including sites with MTBE, sites with ethanol, and sites using no oxygenate; and b. Conducting broader, comparative studies of levels of MTBE, ethanol, benzene, and other gasoline compounds in drinking water supplies in areas using primarily MTBE, areas using primarily ethanol, and areas using no or lower levels of oxygenate.

Treatment and Remediation 7. EPA should work with Congress to expand resources available for the up front funding of the treatment of drinking water supplies contaminated with MTBE and other gasoline components to ensure that affected supplies can be rapidly treated and returned to service, or that an alternative water supply can be provided. This could take a number of forms, including but not limited to:

a. . Enhancing the existing Federal Leaking Underground Storage Tank Trust Fund by fully appropriating the annual available amount in the Fund, ensuring that treatment of contaminated drinking water supplies can be funded, and streamlining the procedures for obtaining finding;

b. Establishing another form of fbnding mechanism which ties the funding more directly to the source of contamination; and C. Encouraging states to consider targeting State Revolving Funds (SRF) to help accelerate treatment and remediation in high priority areas.

8. Given the different behavior of MT3E in groundwater when compared to other components of gasoline, states in RFG and Oxyfuel areas should reexamine and enhance based on their proximity to drinking water supplies.  state and federal "triage" procedures for prioritizing remediation efforts at UST sites 9. Accelerate laboratory and field research, and pilot projects, for the development and implementation of cost effective water supply treatment and remediation technology, and harmonize these efforts with other publidprivate efforts underway. Recommendations for Blendinv Fuel for Clean Air and Water Based on its review of the current water protection programs, and the likely progress that can be made in tightening and strengthening those programs by implementing Recommendations 1  9 above, the Panel agreed broadly, although not unanimously, that even enhanced protection programs wit1 not give adequate assurance that water supplies will be protected, and that changes need to be made to the RFG program to reduce the amount of MTBE being used, while ensuring that the air quality benefits of RFG, and fuel supply and price stabifity, are maintained.

Given the complexity of the national fuel system, the advantages and disadvantages of each of the fuel blending options the Panel considered (see Appendix A), and the need to maintain the air quality benefits of the current program, the Pane1 recommends an integratedpackage of actions by both Congress and EPA that should be implemented as quickly aspossihle. The key elements of that package, described in more detail below, are:

Action agreed to broadly by the Panel to reduce the use of MTBE substantially (with some members supporting its complete phase out), and action by Congress to clarify federal and state authority to regulate andor eliminate the use of gasoline additives that threaten drinking water supplies;

0 Action by Congress to remove the current 2 percent oxygen requirement to ensure that adequate fuel supplies can be bIended in a cost effective manner while quickly reducing usage of MTI3E; and 0 Action by EPA to ensure that there is no loss of current air quality benefits.

The Oxvgen Reauirement 10. The current Clean Air Act requirement to require 2 percent oxygen, by weight, in RFG must be removed in order to provide flexibiJity to blend adequate fuel supplies in a cost effective manner while quickly reducing usage of MTBE and maintaining air quality benefits.

The Panel recognizes that Congress, when adopting the oxygen requirement, sought to advance several national policy goals (energy security and diversity, agricultural policy, etc) that are beyond the scope of our expertise and deliberations.

The Panel further recognizes that if Congress acts on the recommendation to remove the requirement, Congress will likely seek other legislative mechanisms to fulfill these other national policy interests.

Maintaining Air Benefits  1 1. Present toxic emission performance of RFG can be attributed, to some degree, to a combination of three primary factors: (1) mass emission performance requirements; (2) the use of oxygenates; and (3) a necessary compliance margin with a per gallon standard. In Cal RFG, caps on specific components of fuel is an additional factor to which toxics emission reductions can be attributed.

6 Outside of California, lifting the oxygen requirement as recommended above may lead to fuel reformulations that achieve the minimum performance standards required under the 1990 Act, rather than the larger air quality benefits currently observed. In addition, changes in the RFG program could have adverse consequences for conventional gasoline as well.

Within California, lifting the oxygen requirement will result in greater flexibility to maintain and enhance emission reductions, particularly as CaIifornia pursues new formulation requirements for gasoline.

In order to ensure that there is no loss of current air quality benefits, EPA should seek appropriate mechanisms for both the RFG Phase I1 and Conventional Gasotine programs to define and maintain in RFG 11 the real world performance observed in RFG Phase I while preventing deterioration of the current air quality performance of conventional gasoline?

There are severa1 possible mechanisms to accomplish this. One obvious way is to enhance the mass based performance requirements currently used in the program. At the same time, the Panel recognizes that the different exhaust components pose differential risks to public health due in large degree to their variable potency. The Panel urges EPA to explore and implement mechanisms to achieve equivalent or improved public health results that focus on reducing those compounds that pose the greatest risk.

Reducing the Use of MTBE 12. The Panel agreed broadly that, in order to minimize current and future threats to drinking water, the use of MTBE should be reduced substantially. Several members believed that the use of M m E should be phased out completely. The Panel recommends that Congress act quickly to clarify federal and state authority to regulate andor eliminate the use of gasoline additives that pose a threat to drinking water supplies?

The Panel is aware of the current proposal for further changes to the sulfur levels of gasoline and recognizes that implementation of any change resulting fiom the Panel's recommendations wiI1, of necessity, need to be coordinated with implementation of these other changes. However, a majority of the Panel considered the maintenance of current RFG air quality benefits as separate fiom any additional benefits that might accrue from the sulfur changes currently under consideration.

' Under $2 1 1 of the 1990 Clean Air Act, Congress provided EPA with authority to regulate fuel formulation to improve air quality. In addition to EPA's national authority, in $2 1 l( c)( 4) Congress sought to balance the desire for maximum uniformity in our nation's fuel supply with the obligation to empower states to adopt measures necessary to meet national air quality standards. Under $21 l( c)( 4), states may adopt regulations on the components of fuel, but must demonstrate that 1) their proposed regulations are needed to address a violation of the NAAQS and 2) it is not possible to achieve the desired Outcome without such changes.

The Panel recommends that Federal law be amended to clarify EPA and state authority to regulate and/ or eliminate gasoline additives that threaten water supplies. It is expected that this would be done initially on a national level to maintain uniformity in the fuel supply. For further action by the states, the granting of such authority should be based upon a similar two Part test:

I ) states must demonstrate that their water resources are at risk from MTBE use, above and beyond the risk posed by other gasoline components at levels of MTBE use. present at the time of the request. (continued ...)

i 7 initial efforts to reduce should begin immediately, with substantial reductions to begin as soon as Recommendation IO above  the removal of the 2 percent oxygen requirement  is implemented4. Accomplishing any such major change in the gasoline supply without disruptions to fuel supply and price will require adequate lead time  up to 4 years if the use of MTBE is eliminated, sooner in the case of a substantial reduction (e. g. returning to historical levels of MTBE use).

'The Panel recommends, as well, that any reduction should be designed so as to not result in an increase in MlBE use in Conventional Gasoline areas.

13. The other ethers (e. g. ETBE, TAME, and DIPE) have been less widely used and less widely studied than MTBE. To the extent that they have been studied, they appear to have similar, but not identical, chemical and hydrogeologic characteristics. The Panel recommends accelerated study of the health effects and groundwater characteristics of these compounds before they are allowed to be placed in widespread use.

In addition, EPA and others should accelerate ongoing research efforts into the inhalation and ingestion health effects, air emission transformation byproducts, and environmental behavior of oxygenates and other components likely to increase in the absence of MTBE. This should include research on ethanol, alkylates, and aromatics, as well as of gasoline compositions containing those components.

14. To ensure that any reduction is adequate to protect water supplies, the Panel recommends that EPA, in conjunction with USGS, the Departments of Agriculture and Energy, industry, and water suppliers, should move quickly to:

a. Conduct short term modeling analyses and other research based on existing data to estimate current and likely future threats of contamination;

b. Establish routine systems to collect and publish, at least annually, all available monitoring data on:

' (... continued)

2) states have taken necessary measures to restrictleliminate the presence of gasoline in the water resource. To maximize the uniformity with which any changes are implemented and minimize impacts on cost and he1 supply, the Panel recommends that EPA establish criteria for state waiver requests including but not limited to:

a.

b. C.

d. Water quality metrics necessary to demonstrate the risk to water resources and air quality metrics Compliance with federal requirements to prevent leaking and spilling of gasoline. Programs for remediation and response. A consistent schedule for state demonstrations, EPA review, and any resulting regulation of the volume of gasoline components in order to minimize disruption to the fuel supply system.  to ensure no loss of benefits from the federal RFG program.

Although a rapid, substantial reduction will require removal of the oxygen requirement, EPA should, in order to enable initial reductions to occur as soon as possible, review administrative flexibility under existing law to allow refiners who desire to make reductions to begin doing so.

8 ;in as nt  out the %

suit e i use of MTBE, other ethers, and Ethanol; levels of MTBE, Ethanol, and petroleum hydrocarbons found in ground, surface and drinking water; trends in detections and levels of MTBE, Ethanol, and petroleum hydrocarbons in ground and drinking water;

C. Identi& and begin to collect additional data necessary to adequately assess the current and potential future state of contamination.

The Wintertime Oxvfuel Program The Wintertime Oxyfuel Program continues to provide a means for some areas of the country to come into, or maintain, compliance with the Carbon Monoxide standard. Only a few metropolitan areas continue to use MTBE in this program. In most areas today, ethanot can and is meeting these wintertime needs for oxygen without raising volatility concerns given the season.

15. The Panel recommends that the Wintertime Oxyfuel program be continued (a) for as long as it provides a useful compliance and/ or maintenance toot for the affected states and metropolitan areas, and (b) assuming that the clarification of state and federal authority described above is enacted to enable states, where necessary, to regulate and/ or eliminate the use of gasoline additives that threaten drinking water supplies.

Recommendations for Evaluating and Learning From ExDerience The introduction of reformulated gasoline has had substantial air quality benefits, but has at the same time raised significant issues about the questions that should be asked before widespread introduction of a new, broadly used product. The unanticipated effects of RFG on groundwater highlight the importance of exploring the potential for adverse effects in all media (air, soil, and water), and on human and ecosystem health, before widespread introduction of any new, broad! y used, product.

16. In order to prevent future such incidents, and to evaluate of the effectiveness and the impacts of the RFG program, EPA should:

a. Conduct a full, multi media assessment (of effects on air, soil, and water) of any major new additive to gasoline prior to its introduction;

b. Establish routine and statistically valid methods for assessing the actual composition of RFG and its air quafity benefits, including the development, to the maximum extent possible, of field monitoring and cmissions characterization techniques to assess "real world" effects of different blends on emissions;

C. Establish a routine process, perhaps as a part of the Annual Air Quality trends reporting process, for reporting on the air quaIity results from the RFG program; and d. Build on existing public health surveillance systems to measure the broader impact (both beneficial and adverse) of changes in gasoline formulations on public health and the environment.

9 ...

10 B , Summary of Dissenting Opinion By Todd C. Sneller, Member EPA Blue Ribbon Panel The complete text of ME Sneller 's dissenting opinion on the Panel's recommendation to eliminate the federal oxygen standard for reformulated gasoline is included in Chapter 4 of this report.

In its report regarding the use of oxygenates in gasoline, a majority of the Blue Ribbon Panel on Oxygenates in Gasoline recommends that action be taken to eliminate the current oxygen standard for reformulated gasoline. Based on legislative history, public policy objectives, and . information presented to the Panel, Z do not concur with this specific recommendation. The basis for my position follows:

The Panel's report concludes that aromatics can be used as a safe and effective replacement for oxygenates without resulting in deterioration in VOC and toxic emissions. In fact, a review of the legislative history behind the passage of the Clean Air Act Amendments of 1990 clearly shows that Congress found the increased use of aromatics to be harmful to human health and intended that their use in gasoline be reduced as much as technically feasible.

The Panel's report concludes that oxygenates fail to provide overwhelming air quality benefits associated with their required use in gasoline. The Panel recommendations, in my opinion, do no accurately reflect the benefits provided by the use of oxygenates in reformulated gasoline. Congress correctly saw a minimum oxygenate requirement as a cost effective means to both reduce levels of harmful aromatics and help rid the air we breathe of harmful pollutants.

The Panel's recommendation to urge removal of the oxygen standard does not fully take into account other public policy objectives specifically identified during Congressional debate on the 1990 Clean Air Act Amendments. While projected benefits related to public health were a focal point during the debate in 1990, energy security, national security, the environment and economic impact of the Amendments were clearly part of the rationale for adopting such amendments. It is my belief that the rationale behind adoption of the Amendments in 1990 is equally valid, if not more so, today.

Congress thoughtfully considered and debated the benefits of reducing aromatics and requiring the use of oxygenates in reformulated gasoline before adopting the oxygenate provisions in 1990. Based on the weight of evidence presented to the Panel, I remain convinced that maintenance of the oxygenate standard is necessary to ensure cleaner air and a healthier environment. I am also convinced that water quality must be better protected through significant improvements to gasoline storage tanks and containment facilities. Therefore, because it is directly counter to the weight of the vast majority of scientific and technical evidence and the clear intent of Congress, I respectfully disagree with the Panel recommendation that the oxygenate provisions of the federal reformulated gasoline program be removed from current law.

11 I2 LYONDELL CHEMICAL COMPANY SUMMARY OF DISSENTING REPORT The complete text of Lyondell s dissenting report is in Chapter 4 of this report.

While the Panel is to be commended on a number of good recommendations to improve the current underground storage tank regulations and reduce the improper use of gasoline, the Panel's recommendations to limit the use of MTBE are not justified.

Firstly, the Panel was charged to review public health effects posed by the use of oxygenates, particularly with respect to water contamination. The Panel did not identify any increased public health risk associated with MTBE use in gasoline.

Secondly, no quantifiable evidence was provided to show the environmental risk to drinking water from leaking underground storage tanks (LUST) wilI not be reduced to manageable levels once the 1998 LUST regulations are fully implemented and enforced. The water contamination data relied upon by the panel is largely misleading because it predates the implementation of the LUST regulations.

Thirdly, the recommendations fall short in preserving the air quality benefits achieved with oxygenate use in the existing RFG program. The air quality benefits achieved by the RFG program will be degraded because they fall outside the control of EPA's Complex Model used for RFG regulations and because the alternatives do not match all of MTBE's emission and gasoline quality improvements.

Lastly, the recommendations will impose an unnecessary additional cost of 1 to 3 billion dollars per year (3  7 c/ gal. RFG) on consumers and society without quantifiable offsetting social benefits or avoided costs with respect to water quality in the future.

Unfortunately, there appears to be an emotional rush to judgement to limit the use of MTBE. For the forgoing reasons, Lyondell dissents from the Panel report regarding the following recommendations:

The recommendation to reduce the use of MTBE substantially is unwarranted given that no increased public health risk associated with its use has been identified by the Panel.

The recommendation to maintain air quality benefits of RFG is narrowly limited to the use of EPA's RFG Complex Model which does not reff ect many of the vehicle emission benefits realized with oxygenates as identified in the supporting panel issue papers. Therefore, degradation of air quality will occur and the ability to meet the Nation's Clean Air Goals will suffer under these recommendations.  ., i i .. .. ' !

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f 14 :

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7 CHAPTER 2. ISSUE SUMMARIES In the course of its deliberations, the Blue Ribbon Panel heard from a number of experts in the field, and reviewed a large number of analyses and reports compiled by a range of organizations and individuals on the topics of air quality, water contamination, prevention and remediation, fuel supply and price, and health effects (see References below). In order to guide its development and evaluation of the range of options, and the selection of its recommended option, the Panel worked with its own staff, staff of a number of federal agencies, and consultants assigned to it from ICF Consulting to compile the following Issue Summaries.

These Issue Summaries are not intended to be complete reproductions of the many analyses and reports the Panel reviewed, nor did the Panel necessarily have the charter or the expertise to conduct an entire de novo review of all of the evidence on any one topic (e. g. health effects). Rather, these summaries are designed to summarize all of the available information in a relatively neutral manner, capturing those areas where the scientific and technical community have come to some conclusions about these topics, and noting those areas where either there is not agreement, or where additional information is needed.

For example, the Panel provides in Issue A. Water Contamination, the first systematic summary of water contamination data from the states of Maine and California and from the U. S. Geological Survey. This data, which emerged beginning late last year, was augmented substantially by analyses completed by USGS, and a summary of the relevant data was presented to the Panel in April. The Panel did not, however, conduct a detailed review of the analytic techniques, assumptions, and methods of each study, but rather accepted them as valid efforts to attempt to characterize an emerging situation, and refers the readers to the original studies for further detail.

15 i ...

I6 .. .. A. Water Contamination I. Introduction There have been increasing detections of methyl tertiary butyl ether (MTBE) in ground waters and in reservoirs. Overall, approximately 90 percent of tested waters have no detects, with remaining waters generally exhibiting relatively low level contamination. As sources of water contamination are identified, the behavior of oxygenates in ground water needs to be analyzed in order to understand the extent of contamination. The following is a summary of what is known today concerning water contamination.

11. Contamination A. Concentration Levels in Public and Private Wells The use of MTBE in the RFG program has resulted in growing detections of MTBE in drinking water, with between 5 percent and 10 percent of community drinking water supplies in high oxygenate use areas5 showing at least detectable amounts of MTBE. The great majority of these detections to date have been well below levels of public health concern, with between 0.3 percent to 1.5 percent rising to levels above 20 parts per billion (ppb). Detections at lower levels have, however, raised consumer taste and odor concerns that have caused water suppliers to stop using some water supplies and to incur costs of treatment and remediation. Private wells have also been contaminated and these wells are less protected than public drinking water supplies and not monitored for chemical contamination. There is also evidence of contamination of surface waters, particularly during summer boating seasons. A variety of studies, summarized in Table 1, have sought to determine the extent of MTBE contamination of drinking water sources. In addition, the USGS 12 Northeastern State Study has compiled data for MTBE levels in community drinking water.

Although there are no nation wide drinking water data sets from which to fully characterize MTBE detections in the United States, a recent United States Geological Surve); (USGS) report examines this issue with respect to ambient ground water. This report assessed studies conducted between 1985 and I 995 by USGS NAWQA (National Water Quality Assessment Program), local, State, and Federal agencies by examining sampling data from 2,948 urban & rural, drinking water, and non drinking water wells. Projections from these data sets suggest that up to 7 percent of the nation's ground water resources could potentially contain a volatile organic compound (VOC) such as MTBE at concentrations of at least 0.2 ppb. At this time it is difficult to project future trends of contamination due to the lack of time series data.

..+ .. .? t: '

,. &;: ' :

17 ' I Table 1. Summary of Studies Examining MTBE Contamination of Drinking W ater Sources ~.

j California I Maine Maine ' USGS/ EPA12 1 Public Water , Public Water 1 Privatewater I ' usGsmAwQA i Northeastern State I Sources' (wells) ! Sources' (wells) j Sources' (wells) ' ; Stud,+ ' Studies' (wells)

i Concentration i (PPW I N 5,195 N 793 1 ~~9 4 6 (9 5 %~1 ) 1 m L 4 .2 p P b 1 N 1,190 N= 2,743 mJA* I PPb : mL+* I PPb ; (censor level) MDL I ppb'

Non Detects 99% 84.1% 84.3% 94.7% 92.8%

MDL  5 ppb NIA' 14.6% 12.8%  4.5% 5.0%

5 20 ppb 0.3% 0.9. h 1.5% 4.4% 1.3%

> 20 ppb 0.3% 0.4% 1.5% 4 .4 % 0.9%

'California Department of Health Services, April 22, 1999 ( u; ww. dlis. ca. e; ov/~ s/ ddwcm/ chcmical~~ TBE/ int~ summaw. htni). Because the same source may be counted more than once (e. g., as both "raw" and "treated", as with a reservoir), data from a single source have been consolidated for pulposes of counting "sources." zAlthough there have been detects below 5 ppb, such detections are not required to be reported. 'AX. Smith, Analysis of MTBE data in public and private water sources sampled as part of the Maine MTBE Drinking Water Study

'Data are available for other sources (e.& springs and surface water). 'P. J. Squillace, D. A. Bender, J. S. Zogorski, Analysis of USGS data on MTBE in wells sampled as part of the National Water Quality %. J. Grady, Analysis of the Preliminary Findings of the 12 State MTBENOC Drinking Water Study, 1993 1998: Communication to US.

'Some samples with higher reporting levels have not been screened out. Note: Some systems have multiple sources and the total number of sources is unknown. Systems with multiple detections are counted in the "MDt" = Minimum Detection Level. Preliminary Report, October 13, 1998: Written Communication to U. S. EPA, May 20, 1999.

Assessment Program, 1993 1998: Written Communication to U. S. EPA. May 20, 1999.

EPA, May 20,1999.

highest reported concentration range.

MTBE was the second most commonly detected VOC in water fiom urban wells6. Due to the inadequacy of long term monitoring data, the extent and trends of ground and surface water contamination in the nation are still not well known. As such, research is underway to obtain more contamination Occurrence data for ground and surface waters. An American Water Works Association Research Foundation (AWWARF) study of the national occurrence of MTBE in sources of drinking water (i. e., rivers, reservoirs, ground water, etc.) began in May 1999 and win continue for two years. This type of data will document near term impacts and provide important input for analysis to predict future Contamination trends.

B. RFGIOXY Areas Versus Non RFG/ OXY Areas Data from the joint USGS and U. S. Environmental Protection Agency (EPA) 12 Northeastern State study7 and the USGSNAWQA study (Table 1) were analyzed to evaluate the frequency of MTBE detections in drinking water in RFG/ OXY versus non RFG/ OXY areas. Results from the WSGSEPA Northeastern State study indicate that MTBE is detected ten times more often in drinking water from ' Paul Squillace, et al., "Occurrence of the Gasoline Additive MTBE in Shallow Ground Water in Urban and Agricultural Areas; Fact Sheet FS 114 95; U. S. Geological Survey: Rapid City, DS, 1995; Paul Squillace, et. al., Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993 1994. Environ. Sci. Tech. 30 (5) 1721 1730, 1996.

U. S. Environmental Protection Agency and United States Geological Survey, Preliminary Finding of the IZ Stare h4TBEWOC Drinking Water Retrospective, 1999.

18 community water sys jn non RFG/ OXY are UG/ OXY areas (Tab ppb) are 19 times mol detections are clearly ethylbenzene, and xyl G ) or oxygenated fuels (OXY) than tes a similar detection frequency in that higher levels of MTBE (> 20 n non R. FG/ OXY areas. 9 MTBE 2X (benzene, toluene,

Table 2. on RFG/ OXY Areas"

Non RFG/ OXY Areas in the United States (2,263) 2% 1 2%

After normalizing for factors that affect detection frequency (i. e., gasoline stations, commercial and industrial land use, etc.), MTBE is four to six times more likely to be detected in RFG/ OXY areas than non RFG/ OXY areas. In RFG/ OXY areas, of the 50 million people dependent on ground water, 20 million use an aquifer containing at least one VOC, indicating potential vulnerability to MTBE."

C. Co Occurrence of MTBE and Other Gasoline Components For co occurring components in gasoline, preliminary data from both the USGSEPA 12 Northeastern State study and the USGSNAWQA study shows that MTBE is generally detected in groundwater samples that contain another VOC, but is not associated with BTEX detections. In USGSEPA drinking water samples containing MTBE, BTEX co occurrence were only 0.3 percent, even though approximately 44 percent of the samples contained one or more other VOCs. 12 Similar results are exhibited for USGSNAWQA ground water samples containing MTBE, with only 13 percent of the samples with MTBE also detecting BTEX. I3 ' Stephen Grady and Michael Osinski, "Preliminary Findings of the 12 State MTBENOC Drinking Water Retrospective," presentation at the April 1999 MTBE Blue Ribbon Panel meeting.

Paul Squillace, "MTBE in the Nation's Ground Water, National Water Quality Assessment (NAWQA) Program Results," presentation at the April 1999 MTBE Blue Ribbon Pane1 meeting.

lo Paul Squillace, "MTBE in the Nation's Ground Water, National Water Quality Assessment (NAWQA) Program Results," presentation at the April 1999 MTBE Blue Ribbon Panel meeting.

" Paul Squillace, "Volatile Organic Compound in Untreated Ambient Groundwater of the United States, 1985  1995," presentation at the April 1999 MTBE Blue Ribbon Panel meeting.

'* Stephen Grady *and Michael Osinski, "Preliminary Findings of the 12 State MTBENOC Drinking Water Retrospective" presentation at the April 1999 MTBE Blue Ribbon Panel meeting.

'' Paul Squillace, "Volatile Organic Compound in Untreated Ambient Groundwater of the United States, 1985  1995," presentation at the April 1999 MTBE Blue Ribbon Panel meeting.

19 111. Sources The most frequent sources of higher levels of ground water contamination (greater than 20 ppb) I4 appear to be releases from gasoline storage and distribution systems, although there have been reports (e. g., Maine) that would suggest other sources of contamination, such as small spills and improper disposal. In reservoirs and lakes, MTBE detections, which vary seasonally, appear to be from recreational watercraft, particularly those with older motors. More general contamination of ground and surface waters at lower levels (usually less than 5 ppb) are primarily from storm water runoff and to a lesser degree, air deposition, as well as from leaking tanks and accidental spills.

Specific examples of recent findings regarding the sources of ground water contamination include the following:

a. Santa Monica. California's Ground water contamination from LUSTS has resulted in the contamination and closure of 9 high volume production drinking water wells (daily water demand at approximately 6.5 million gallons per day) at levels up to 6 10 ppb in the production wells, up to 17,000 ppb in regional monitoring wells, and up to 230,000 ppb in LUST source site monitoring wells.

b. Maine16 An automobile gasoline leak contaminated a supply well 100 feet away to a level of 900 ppb.

c. University of California. Davis Donner Lake Study"

The use of motorized watercraft yielded concentration levels from 0.1 ppb to 12 ppb.

l 4 Office of Science and Technology Policy, National Science and Technology Council, Interagency Assessment of Oxygenated Fuels, June 1997.

Komex H20 Science, Draft Investigation Report of MTBE Contamination: City of Santa Monica, Charnock Well Field Los Angeles, California, March 2 1, 1997; Geomatrix Consultants, Inc., Summary oflMTBE Groundwater Monitoring Results, Fourth Quarter 1998, Charnock Well Field Regional Assessment, Los Angeles, California, April 1, 1999.

l6 B. Hunter et al., "Impact of Small Gasoline Spills on Groundwater," preliminary report abstract presented at the Maine Water Conference Meeting, April 1999.

I' J. E. Reuter et al., "Concentrations, Sources and Fate of the Gasoline Oxygenate Methyl Tert Butyl Ether (MTBE) in a Multiple Use Lake," Environmental Science and Technology 32, 3666 3672, 1998.

20 d. MetroDolitan Water District of Southern Caiifornia Monitoring Program"

A monthly monitoring program (January 1997 to present) at six surface water reservoirs resulted in concentrations as high as 29 ppb during summer boating months.

e. OSTP Re~ 01 t'~

Storm water runoff exhibited concentrations of 0.2  8.7 ppb in 7 percent of samples tested in 16 cities from 1991 to 1995. Based on modeled air concentrations, concentrations in rainwater are predicted to range from less than 1 ppb to 3 ppb.

N. Behavior A. MTBE In ground water, MTBE is more soluble, does not adsorb as readily to soil particles, biodegrades less rapidly, and thus moves more quickly than other components of gasoline (Le., BTEX). Zo In surface water, volatilization of MTBE at the air water interface is a significant contributor to decreased concentrations of MTBE."

Much of MTBE's behavior is dependent upon the nature of the release, whether the release source is point or non point, its geologic settings, and environmental and microbial factors. In studies to date, in situ biodegradation of MTBE has been minimal or limited at best, which is significantly less (by at least one order of magnitude) when compared to benzene.

B. Ethanol Ethanol is extremely soluble in water and, based on theory, should travel at about the same rate as MTBE. Ethanol is not expected, however, to persist in ground water, due to ethanol's ability to biodegrade easily. In fact, laboratory research findings suggest that ethanol may inhibit the I s Metropolitan Water District, Methyl Tertiary Butyl Ether Monitoring Program ut the Metropolitan Water District of Southern California, monitoring program update, April 1999.

l 9 Office of Science and Technology Policy, National Science and Technology Council, Interagency Assessment of Oxygenated Fuels, June 1997, pp. 2 33  2 35.

2o A. M. Happel et al., An Evaluation ofMTBE impacts to Culyornia Groundwater Resources, Lawrence Livermore National Laboratory Report, UCRL AR 130897, June 1998; A. M. Happel, B. Dooher, and E. H. Beckenbach, "Methyl Tertiary Butyl Ether (MTBE) Impacts to California Groundwater," presentation at the March 1999 MTBE Blue Ribbon Panel meeting; Salanitro, J. P., "Understanding the Limitations of Microbial Metabolism of Ethers Used as Fuel Octane Enhancers," Curr. Opin. Biotechnol. 6: 337 340, 1995.

*' Paul Squillace et al., "Review of the Environmental Behavior and Fate of Methyl Tertiary Butyl Ether," Environ. Tox. Chem, 1997; UC Davis Report, Transport and Fate Modeling of MTBE in Lakes and Reservoirs," Stephen A. McCord and Geoffiey S., Schladow.

21 biodegradation of BTEX because the microbes preferentially metabolize ethanol before BTEX. 22 Qualitative and quantitative characterizations of ethanol biodegradation under field conditions have not been done to date. In one hypothetical analysis presented to the Panel, the addition of ethanol to gasoline was estimated to extend BTEX plumes by 25 percent to 40 percent. 23 Additionally, a study in Brazil indicated that, high ethanol concentrations in ground water (greater than 2 percent) enhanced the solubilization and migration of BTEX. 24 No national monitoring of ethanol in ground water, surface water or drinking water has been completed at this time. 25 V. Drinking Water Standards A. Drinking Water Advisory In certain situations, either the public's concern about potential contamination, or water supply officials' concerns about the taste and odor effects of MTBE contamination, or both, has affected the ability of local authorities to rely on their water supplies for drinking water. For example, South Lake Tahoe, California water oficials recently closed 13 wells due to the proximity of MTBE plumes to its drinking water wells.

The U. S. Environmental Protection Agency's Office of Water has established a drinking water advisory26 level of 20 to 40 ppb as a guidance for State and local authorities, based on taste and odor concerns. This guidance suggests control levels for taste and odor acceptability and also provides a large margin of safety against any potential adverse health effects. The advisory levels enable water suppliers to easily assess if their drinking water is likely to be acceptable to consumers. The advisory also recognizes that some members of the population may detect it below this range. However, as indicated in table 3, states have established different guidelines and standards based on differing interpretations of the data concerning the taste and odor thresholds and health effect studies for MTBE.

In addition, EPA has proposed a revised Unregulated Contaminant Monitoring Rule, which would require large water systems (serving more than 10,000 persons) and a representative sample of small and medium sized water systems (serving fewer than 10,000 persons) to monitor and report MTBE levels. This program is scheduled to take effect in January 2001. Under this regulation, the majority of 22 H. X., Corseuil et al., "The Influence of the Gasoline Oxygenate Ethanol on Aerobic and Anaerobic BTX Biodegradation," Wat. Res., 1998, 32,2065 2072.; C. S. Hunt et al., "Effect of Ethanol on Aerobic BTX Degradation Papers from the Fourth International In Situ and On Site Bioremediation Symposium," Battelle Press, April May 1997, pp. 49 54.

23 Michael Kavanaugh and Andrew Stocking, "Evaluation of the Fate and Transport of Ethanol in the Environment," November, 1998. Presentation at the May 1999 MTBE Blue Ribbon Panel. [Based on Malcome Pirnie, Inc. Evaluation of the Fate and Transport of Ethanol in the Environment (Oakland, CA, 1998.)]

24 H. X. Corseuil and P. J. J. Alvarez, "Natural Bioremediation Perspective for BTX Contaminated Groundwater in Brazil," Wat. Sei. Tech., 1996,35,9 16.

2s EPA analytical methods are limited for ethanol analysis providing only ppm range detection limits.

26 U. S. Environmental Protection Agency, Office of Water, Drinking Water Advisory: Consumer Acceptability Advice and Health Eflects Analysis on Methyl Tertiary Butyl Ether (MTBE)), December 1997.

22 F `

i *. public groundwater supply wells will still not be monitored for MTBE.* ' The availability of Consumer Confidence Reports will notify the public of what contaminants are found in drinking water. Increasing numbers of consumers may find the water unacceptable if they are aware of MTBE's presence.

private wells are not subject to monitoring under the Safe Drinking Water Act, but are left to the discretion of the State. Therefore, private well owners rarely have routine monitoring for either bacterial or chemical contamination. Private wells are typically more vulnerable than public wells due to differences in wellhead construction. Specifically, these wells typically draw from shallow groundwater, which is more vulnerable to impacts from surface contamination.

€3. State Guidelines and Action Levels As Table 3 indicates, a number of States have established drinking water guidelines and action levels. Currently, four States have primary drinking water standards, three States have enforceable guidelines, and 12 States either have an MTBE guideline or action level in place. Figure Al, located in Appendix A, contains a map illustrating these various State standards.

Table 3. State Drinking Water Standards, Guidelines, and Action Levels 1 Maine (35 ppb) New Jersey (70 ppb) 1 : New York (50 ppb)

~

South Carolina (20 40 ppb) States with Primary Drinking Water Standards (health based)

State with a Secondary Standard (aesthetic) California (5 ppb); enforceable States with Enforceable Guideiines Michigan (240 ppb); health based West Virginia (20 40 ppb); EPA Advisory Arizona (35 ppb); health based California (13 ppb); health based Connecticut (70 ppb); health based Illinois (70 ppb); health based Kansas (20 40 ppb); EPA Advisory Maryland (10 ppb); aesthetically based Massachusetts (70 ppb); health based ' New Hampshire (1 5 ppb); aesthetically based Pennsylvania (20 40 ppb); EPA Advisory Rhode Island (20 40 ppb); EPA Advisory Vermont (40 ppb); EPA Advisory Wisconsin (60 ppb); health based States with a Guideline or Action Level in Place Source: U. S. Environmental Protection Agency.

Water suppliers are required to monitor for volatile organic compounds and MTBE can be analyzed by the 21 Same analytical methods and therefore could be included along with scheduled volatile organic compound sampling.

23  . ,. . .

National Primary Drinking Water Standards, as defined by the Safe Drinking Water Act (SDWA), must be health based. Although standards can be developed at the Federal level based on taste and odor, such standards are secondary and non enforceable. Currently, the Drinking Water Advisory serves only as a national guidance level for aesthetic effects that EPA recommends for drinking water. Due to uncertainties in the health effects database, gaps in characterizing national occurrence, and significant variability among health study methodologies, EPA does not have sufficient information to establish an enforceable health based standard at this time. . . I ,. . . . ,. . . ..   _.. . ..  .. ... . B. Air Quality Benefits I. Introduction The Federal and California reformulated gasoline (RFG) programs have significantly improved air quality by reducing emissions of toxics and lowering the ozone forming potential through reductions in volatile organic compound (VOC) and oxides of nitrogen (NO,). In general, these programs have resulted in greater emission reductions than statutorily required.

11. Federal RFG Program: Requirements and Benefits A. Summary of RFG Requirements and Benefits Ozone and air toxic levels in this nation have decreased substantially in recent years as a result of the Clean Air Act's implementation. There are over 30 areas, however, that are still in nonattainment with the current ozone standard. The results of emissions tests, tunnel studies, and remote sensing of tail pipe exhaust indicate that RFG usage can cause a decrease in both the exhaust and evaporative emissions from motor Environmental Protection Agency (EPA) and the State of California, when compared to all available control options, RFG is a cost effective approach to reducing ozone precursors such as VOCs and NO,? 9 Although there is no National Ambient Air Quality Standard for toxics, a number of provisions of the Clean Air Act require reductions in toxics emissions, and Federal RFG has contributed to these reductions.. Based on separate cost effectiveness analyses conducted by both the U. S.

The RFG program, mandated under the 1990 Clean Air Act Amendments, requires changes in motor fuel formulation which result in decreased vehicle emissions for areas in the U. S. with significant low level ozone pollution, otherwise known as smog. These areas represent about 30 percent of U. S. gasoline consumption. The program requires reductions relative to a 1990 fuel baseline in levels of NO,, toxics, and VOC emissions and also requires a minimum level of oxygen and limits the maximum benzene level. The emissions performance of fuels relative to 1990 is evaluated using a linear regression model, referred to as the "complex model," which was developed using thousands of emissions tests relating fuel properties to emissions performance. To certify a fuel as RFG, a fuel manufacturer measures the eight relevant physical and chemical properties of the fuel, enters those results into the complex model, and the model determines the percent reduction in NO,, VOC, and toxics, relative to 1990, for that fuel. Phase I of the program began in 1995. Phase 11, scheduled to begin on January 1 , 2000, will implement more stringent NO,, VOC and toxics reduction standards.

The best available data indicate that the RFG program has substantially reduced emissions of ozone precursors and toxics (See Table 1). Analysis of fuel data reported by refiners for 1995 through 1998 indicates that emission reduction benefits exceeded the standards for VOCs, NO,, and toxic^.^ ' Toxics National Research Council (NRC), Ozone Forming Potential of Reformulated Gasoline, May 1999.

29 U. S. Environmental Protection Agency, Regulatory Impact Analysis, 59 FR 7716, Docket No. A 92 12, 1993.

30 Refinery Reporting Data and RFG Survey Association Data. Data on gasoline properties contained in this Issue Summary are derived from two primary sources. The RFG reporting data represent data submitted by the (continued.. .)

27 reductions in particular were substantially greater than the standard (an over 33 percent reduction versus a 17 percent requirement). (Refer to Figures B 1 through B3 in this Issue Summary's Appendi~).~ ' In addition, ambient monitoring data also suggest that the RFG program is working. The EPA's 1995 Air Quality Trends report, which coincides with the first year of the RFG program, shows a median reduction of 38 percent in ambient benzene and significant decreases in other vehicle related VOC concentrations in RFG No other control action could have accounted for such a substantial decrease in benzene levels.

In 1998, Northeast States for Coordinated Air Use Management (NESCAUM) conducted an assessment of the toxicity of conventional gasoline (CG) versus RFG sold in the Northeast. This focused on six toxic air pollutants [benzene, 1,3 butadiene, acetaldehyde, polycyclic organic matter (POM), formaldehyde, and MTBE]. A modified version of the complex model, incorporating MTBE emission rates, was used to compare differences in predicted emissions between composited average RFG and conventional fuel types sold in the Northeast. While emissions estimated by the complex model may not accurately represent actual emissions from the motor vehicle fleet, it does provide a means of establishing relative effects of fuel composition on emissions. Relative cancer potencies were assigned to the six compounds to compare carcinogenicity among fuel types. This study concluded that Phase I RFG (in 1996) "served to reduce cancer risk associated with gasoline vapors and automobile exhaust . . . by 12 percent. . . ." and that Phase I1 RFG would "reduce the public cancer risk . . . by 20 percent. . . ." This report also noted that "since the cancer potency of MTBE is significantly less than that of benzene, 1,3 butadiene and POM, its presence in RFG at 10 percent by volume tends to dilute other carcinogens. . . ." The National Research Council (NRC) report also stated that the most significant advantage of oxygenates in fuel appears to be displacement of some air toxics (e. g., benzene from RFG). For additional information on typical fuels and standards, refer to Table B 1 in Appendix B.

30 (.;. continued) universe of RFG producers or importers. The RFG survey data are derived from a carefully planned statistical sampling of retail stations in various RFG cities. The survey plan is designed to estimate average gasoline properties for a given area over a specific time period with a high degree of statistical confidence.

The calculation of VOC, NOx, and toxics reductions is based upon measured properties from these two data sources and is calculated by the "complex model," a regression model based upon thousands of vehicle emissions tests. As with any model, some uncertainty exists regarding the calculated emissions reductions and their applicability for any given fleet in any given year.

31 U. S. Environmental Protection Agency bar charts reflect survey data collected from 19,000 samples during 1998. Data from RFG Survey Association.

32 US. Environmental Protection Agency, National Air Quality and Emissions Trends Report, 1995.

33 NESCAUM, Relative Cancer Risk of Reformulated Gasoline and Conventional Gasoline Sold in the Northeast, August 1998.

28 Table BI. Typical Fuels and Standards  I Federal RFG Phase I Federal RFG Phase I I Conventional Fuel Parameter Gasoline Actual' Comp'ex Averaging California RFG ' Averaging Reid Vapor Pressure (psi) 8.7R. 8 7.9R. O (8.0/ 7.1) 2 (Summer) Avg. Std. Actual Sulfur (ppm) 339 190 (285) (1 50) 20 30 Oxygen (wt%) c0.5 2.26 2.1 min 2.1 min 2.07 (2.0)

Aromatics (vol%) 32 26 (32) (25) 23 22 Olefins (~ 01%) 13 10 (1 0) (11) 4 4 E200 (%) 41 49 (45) (49) 51 (49)

E300 (%) 83 83 (83) (87) 89 (91)

.95 max 0.55 0.8 Benzene (vel%,) 1.5 0.68 0.95 max Phase II complex model performance (A reduction from I990 baseline) of these fuels:

VOC performance 26.1 22.1 29.8 29.9 29.6 NOx Performance 5.3 1.4 6.8 14.6 14.7 Toxics performance 30.1 19.7 28.4 37.0 34 A 1 Standard Standard "Actual" Phase I summer (VOC controlled) RFG properties and performance estimated from 1998 RFG Compliance Surveys. *Properties listed under the Federal RFG "standards" columns in parentheses are not standards perse. but indicate the average properties a summer fuel must have to meet the emissions performance standards. The '/" indicates 'NorthlSouth" specific values. South (VOC Control Region 1) values were used in performance comparisons.

As shown in Table 1, Phase I1 RFG, which takes effect on January 1,2000, requires additional emission reductions, beyond those required in Phase I. With the exception of air toxics and benzene, Phase I1 also requires reductions that are greater than the actual reductions achieved in Phase I. However, for both air toxics and benzene, the Phase I1 requirements, unless changed, would allow the formulation of RFG that does not maintain the current benefits (e. g. a 22 percent reduction in toxics versus a 33 percent actual Phase I reduction).

Table 1. Emission Reductions Required by the RFG Program vocs NOx Toxics Benzene Oxygen Northern States: 17% RFG Phase I (1995 1999) Southern States: 37% 1.5% 17% 1% 2.0 wt%

Northern States: 21.2% (4.9% Average;

3,8%  7,4% (33.2% Average;

0.68 'Yo 2.0 WtYO 23.7% 36.9% Av2, 20.3  25.0% Range I 1998 Southern States: 39.4% Actual RFG' Phase Range) Range)

Av, 38.4  40.3% Range RFG Phase I1 (2000) 27% 6.8% 22% 1 YO 2.0 wt%

29.6% 14.7 34.4 0.8 0  2.0 wt% CaRFG Standards (approx.)

'1998 RFG Compliance Survey Data (summer surveys), completed by the RFG Survey Association. 'Av" = the average of the individual area results weighted by estimated gasoline volume in each area.

29 I. B. CaRFG Program Also, as shown in Table 1, the California RFG program has in place more stringent standards for its Phase I1 than Federal RFG, in particular for NO,, air toxics, and benzene. The second phase in the California RFG program (CaRFGII) is intended to ensure that benefits continue as the vehicle technology advances and fleets turn over. CaRFGII helps automakers meet the increasingly stringent emission standards for new vehicles. California's program requires automakers to certify their vehicles on CaRFGII, thus ensuring that new vehicles will be designed to meet emission standards on a fuel similar to what the vehicles will be operated with during daily use.

The CaRFG program is designed to ensure that different formulations of gasoline will meet the required emissions performance levels. This is accomplished through the predictive model, which allows one to compare the emissions performance of alternative fuel parameters against a standard set of parameters contained in the CaRFG regulation. If the alternative formulation provides emission benefits equal to or better than the standard formulation, emission benefits are preserved and the refiner (or fuel importer) is allowed to market the fuel. To ensure the predictive model reflects the most recent data on the relationship between fuel properties and emissions, the California Air Resources Board (CARB) is in the process of updating the model to reflect newer technology vehicles. This will provide extra assurance that the model will continue to be applicable as the vehicle fleet changes. In California, the predictive model has been used to produce and market fuels with no oxygenates while preserving the program's full air quality benefits.

C. EPA 1998 Area by Area Analysis The EPA's Area by Area analysis of 1998 RFG Survey Data indicates that the complex model emissions performance of RFG in Chicago and Milwaukee, while easily exceeding all Phase I performance (ie., emission reduction) requirements, generally ranks low compared to other RFG areas. In order to investigate factors influencing the performance of Chicago and Milwaukee RFG relative to RFG in other areas, it is necessary to consider the composition of the fuels. Table B2 and an accompanying discussion, located in the Appendix, discuss estimates of average values of the fuel properties that are complex model inputs. The Chicago and Milwaukee properties are averages of the individual summer survey property averages. The National Average properties were esfimated by calculating an average for each of the RFG areas surveyed during 1998, and then weighting these values by estimates of fuel volume for each area. The National Average Reid vapor pressure (RVP) value was for VOC Control Region 2 (North), which includes Chicago and Milwaukee. Other values include both regions. (California oxygen only surveys were not included in the oxygenate computations.)

The higher sulfur levels in Chicago and Milwaukee RFG areas affected its relative complex model performance for all three pollutants (VOC, NO,, toxics). This analysis indicates that sulfur was the primary factor influencing relative VOC and NO, performance, and that sulfur may have some influence on toxics performance. The margin of air toxics overcompliance was not as great in Chicago and Milwaukee as in other areas primarily due to higher benzene content, but other factors such as increased acetaldehyde emissions and sulfur levels also contributed. Oxygenates had little impact on VOC or NO, performance.

30 Table B2. Chicago and Milwaukee Data Chicago Milwaukee National Average MTBE (wt% oxygen) 1.62 0.08 0.06 ETBE (wt% oxygen) 0 0 0 Ethanol (wt% oxygen) 0.5 1 3.38 3.39 TAME (wt% oxygen) 0.12 0 0 RVP (psi) region 2 7.9 7.9 7.9 SULFUR (ppm) 190 255 26 1 E200 (%) 49.4 50.7 50.9 E300 (%) 82.7 81.8 82.2 AROMATICS (~ 01%) 26.0 25.1 24.9 OLEFINS (~ 01%) . 10.3 6.7 7.0 BENZENE (~ 01%) 0.68 0.90 0.99 111. The Impact on RFG if Oxygenates are Removed A. Introduction . MTBE provides about 76 percent of the oxygenate used in all RFG, and ethanol provides about 19 percent. The remaining 5 percent is made up of other ethers, tertiary amyl methyl ether (TAME) and ethyl tertiary butyl ether (ETBE). 34 MTBE and ethanol have been the primary oxygenates in RFG because of their availability, blendability, and ability to deliver air quality benefits while meeting American Society for Testing and Materials (ASTM) specifications. (Refer to Table D1 in Issue Summary D, Fuel Supply and Cost, for usage data and references.)

As shown in Table I above, Phase I RFG currently overcomplies with VOC, NOx, toxics, and benzene requirements. The key question is whether this current overcompliance with the Phase I RFG standards will be maintained in Phase I1 RFG if oxygenates are not required. Because the Phase I1 performance standards for VOCs and NO, are above the current actual performance of Phase I RFG, all fuels will be required to maintain or exceed the current VOC and NOx benefits, whether or not they contain oxygenates. However, since the Phase I1 performance standard for air toxics (22 percent reduction) is below the current Phase I actual reductions (average 33 percent reduction), there is no guarantee that the current (Phase I) level of air toxics benefits will be maintained in all cases The impact of removing oxygenates such as MTBE is not likely to be identical for CaRFG and Federal RFG. Federal RFG is subject to fewer caps on specific properties (e. g. aromatics) than CaRFG and therefore is more likely to show emissions impacts from the removal of oxygenates. Specific fuel parameters (e. g. the CaRFG cap on aromatics) may provide extra assurance that certain pollution reductions occur. Alternatively, performance standards (such as the current mass based requirements for toxics and VOCs) assure that pollution reductions will occur, but allow the refiner more flexibility in determining how to achieve those reductions.

34 Estimate from 1997 FWG Survey Data. '

31 B. Air Toxics Current RFG over complies with both the Phase I and planned Phase I1 toxics standards. With the data available the panel could not determine with precision all of the factors which produce this overcompliance. However, as is explained below, when blending gasoline, it is reasonable to conclude that the use of octane rich oxygenates is one of the factors that affects a refiner's decision to use high octane aromatics, a major contributor to the formation of toxic emissions. 35 Decisions about refinery blending are complex and vary greatly over the range of U. S. refineries. Despite the variability in fuels likely to result from this complex system, however, certain trends can be identified that may help explain the larger than expected air toxics benefits.

8 First, it would be expected that each refiner would incorporate a measurable degree of overcompliance in order to ensure that their fuel never falls below the standard.

8 Second, no matter how refiners blend fuel to meet the air quality standards, fuels will also be blended to maintain at least the minimum octane required for current automobiles. Thus, one would expect that with increased use of oxygenates (a high octane component) in RFG, one would see, on average, reduced need for, and use of, other high octane components such as aromatics. Conversely, one would expect that with reduced use of oxygenates, this octane need would be met, in part, with increased use of aromatics and, in the longer term once capacity is expanded, alkylates. 36 35 Air toxics emissions reductions result primarily from reductions in RFG of aromatics and benzene (itself an aromatic) when compared to pre RFG gasoline.

36 The production of octane quality is the primary performance property considered by refiners in the production of gasoline. All refininghlending decisions are based, in part, on the need for a certain minimum level of octane quality in order that vehicles using the fuel operate properly. There are a limited number of octane rich components that refiners can choose to produce needed octane. Aromatics, alkylates, and oxygenates are three of the most available sources of octane quality for U. S. refiners. The most important (and for most refiners, the most economical) gasoline upgrading process in U. S. refineries is catalytic reforming which produces aromatics and increases the octane quality of the gasoline. (See, for example, Anderson, Robert O., Fundamentals of the Petroleum Industry, University of Oklahoma Press, 1984, p. 221 .) Reforming changes the shape of straight chain carbon molecules to high octane ring shaped molecules. These ring shaped molecules are referred to as aromatics and include benzene and benzene like molecules. Since oxygenates are also primarily used for octane enhancement when producing gasoline, for a refiner using these two octane sources, there exists a gasoline balance situation between the use of aromatics and the use of oxygenates. Although the increased use of alkylates would also be expected as oxygenates are reduced, U. S. reforming capacity to produce aromatics is far greater than is the capacity to produce alkylates.

Under the federal RFG program, the oxygenate requirement results in a high level of octane quality and, for the reasons mentioned above, would be expected to push the use of aromatics and benzene from reforming in a downward direction. (Addition of oxygenate volumes would result in more than a 10 percent decrease .in aromatics and benzene from dilution alone, even if the octane quality properties are ignored.) Refiners would not be expected to utilize refinery capacity to produce aromatics that are not needed for octane. Since aromatics (including benzene) are the strongest contributors to the formation of toxics in the complex model, it is reasonable to conclude that the use of oxygenates and the resulting downward movement in aromatics and benzene is likely responsible for a substantial amount of the overcompliance in toxic emission reductions.

32 e Third, although it is difficult to determine the precise role that oxygenates play in overcompliance, and some fuels would likely be blended by some refiners with lower oxygen yet high air toxics benefits, on average one would expect the presence of higher levels of oxygenate in the fuel to lead to reduced levels of aromatics, and thus greater air toxics benefits.

Although reasonable to assume that oxygenates thus contribute to toxics overcompliance, it is difficult to quantify this effect. The ideal data set would be able to compare fuels blended to meet current RFG requirements with a full range of oxygen levels (i. e. O%, .5%, 1 .O%, 2%, etc.), and such a data set does not exist. There is limited data from the State of Maine which recently implemented its own fuel program, albeit with less stringent requirements than RFG, to substantially reduce the use of MTBE: fuel properties reported by Maine's gasoline suppliers and distributors show a decrease in MTBE use by 50% and a corresponding increase in aromatics of 20% over the levels of aromatics present in RFG sold in .

Maine in 1 99737. There is also data from Northern California (where 2.0% oxygen is not required) that CaRFG sold in the San Francisco area contained over 8% by volume MTBE in 1997 in part to meet the more stringent CARB requirements for CaRFG, although such data must be interpreted carefully since both the RFG requirements and the market situation in California are unique3'.

The only other available data set is data on actual RFG fuel properties collected as part of the implementation of the program. At the Panel's request, EPA analyzed available data on actual RFG properties in the marketplace and the relationship in that data between MTBE use, air toxics and aromatics content. The EPA's regulations allow producers of RFG to meet the oxygen content requirement on an averaged basis and to employ oxygen credits to meet the averaged standard of 2.1 percent by weight. Consequently, the oxygen content in any given sample of RFG may vary to a limited degree from the statutory 2.0 percent by weight per gallon requirement. In 1998 RFG fuel quality surveys, the oxygen content of samples that did not contain ethanol but were oxygenated wholly or in part with MTBE, varied between about 1.5 and 3.0 percent by weight. Even though the availability of this data provides an opportunity to explore how aromatics content changes as oxygen levels vary, most of the data points clustered around the 2.1 percent average standard and the data set contains no data for oxygen levels below the regulatory minimum of 1.5 percent. Therefo. re, although the analyses performed for the Panel showed a weak positive correlation between oxygen levels and both toxics performance and aromatics content, and more recent analyses by the Colorado School of Mines of the same data found some stronger ~orrelations, 3~ the Panel concluded that this data is extremely limited and can not be used for the purpose of coming to any specific quantitative statistical conclusions.

In the absence of certainty on the effects of removing oxygenates, the primary concern is that if the oxygen mandate is removed and a significant amount of RFG does not contain oxygenates, use of aromatics might rise at least in some portion of the RFG fuel blends. Such a rise would likely decrease the overcompliance now seen for toxics in Federal RFG. In California, where CaRFG both requires much lower sulfur levels and places a limit on the level of aromatics allowed in the fuel, such overcompliance is more likely to continue. In the absence of certainty around this issue, the only way to ensure that there is no loss of current air quality benefits is for EPA to seek mechanisms for both the RFG Phase I1 and Conventional Gasoline programs to define and maintain in RFG I1 the real world 37 NESCAUM, RFGMTBE Findings and Recommendations, Boston, MA, August, 1999.

38 University of California, Health and Environmental Assessment of MTBE, Volume I. Summary and Recommendations, P. 16, November 1998.

39 NESCAUM, RFGMTBE Findings and Recommendations, Boston, MA, August, 1999.

33 40 EPA estimate based on complex and MOBILE model calculations.

41 Colorado Department of Public Health and Environment (Ken Nelson and Ron Ragazzi), The Zmpact of a IO percent Ethanol Blended Fuel on the Exhaust Emissions of Tier 0 & Tier I Light Duty Gasoline Vehicles at 35 F, March 26, 1999.

42 This study involved testing light duty vehicles (LDVs) and trucks (LDTs) at 35 "F. Twelve Tier 0 and 12 Tier 1 vehicles (8 LDVs, 4 LDTs), six high emitters, and one low emission vehicle (LEV), were tested under three driving cycles [Federal Test Procedure (FTP), Unified, and REPOS]. The FTP is based on typical urban driving patterns. The Unified Cycle has higher speeds and accelerations than the FTP, and the REP05 is a very aggressive driving cycle. In this program, the FTP was conducted from a cold start while the other cycles were conducted from a hot running start. The vehicles were tested with a non oxygenated fuel and a 10 percent ethanol oxygenated fuel. The program measured emissions of hydrocarbons (HC), COY NOx, carbon dioxide (CO,) and fine particulate (PM 10 and smaller).

The study reported that FTP particulate emissions were reduced with the oxygenated fuel. For the FTP, a mean absolute reduction of 3.3 1 milligrams per mile (mg/ mi) or 36.0 percent was achieved for the main group of 24 Tier 0 plus Tier 1 vehicles. The reduction for the Tier 0 vehicles was 5.24 mg/ mile, or 39.7 percent, and the reduction for the Tier 1 vehicles was 1.38 mg/ mi, or 26.6 percent. These absolute reductions were statistically significant at the 95 percent confidence level. The numbers indicate that older vehicles receive greater PM benefits from the use of oxygenated fuels than newer technology vehicles. No statistically significant differences were detected for other driving cycles. There were no statistically significant changes in particulate emissions for the high (continued.. .)

34 performance observed in RFG Phase I while preventing deterioration of the current air quality performance of conventional gasoline.

There are several possible mechanisms to accomplish this. One obvious way is to enhance the mass based performance requirements currently used in the program. At the same time, the panel recognizes that the different exhaust components pose differential risks to public health due in large degree to their variable potency. EPA should explore and implement mechanisms to achieve equivalent or improved public health results that focus on reducing those compounds that pose the greatest risk.

C. Carbon Monoxide Benefits Although there is no carbon monoxide (CO) standard for RFG, oxygenates affect CO emissions so that current RFG actually produces significant CO benefits. Estimates show that about one fourth of the CO benefits associated with oxygenated RFG will disappear if oxygenates are on used. 40 Thus, if RFG contains no oxygenates, the CO reductions associated with RFG will be reduced by approximately 25 percent. This will be less critical in future years due to stricter tailpipe CO emission standards. As the vehicle fleet turn< over, the oxygenate impact on CO emissions diminishes (see Table 3). It is important to note that there are now relatively few CO nonattainment areas (see discussion of Wintertime Oxyfuel Program in Section V. below).

D. Particulate Matter Benefits There are limited data available on the effect of oxygenates on emissions of particulate matter (PM). The Colorado Department of Public Health and Environment conducted a study to evaluate the effects of oxygenated fuels on motor vehicle emissions at low ambient temperatures! ' The study, which analyzed winter oxygenated fuels rather than RFG, concluded that there were statistically significant PM emissions reductions associated with the use of an ethanol oxygenated fueL4* Additional research is c necessary including use of ethanol oxygenated RFG and non oxygenated RFG fuels in a variety of climates, to better understand how different formulations of gasoline affect PM.

IV. Other Air Quality Considerations for Oxygenates A. Ozone Reactivity of Alternatives (CO Reduction)

One key question that has been raised about the air quality effects of RFG has been whether the ozone reactivity of fuels with different oxygenates could be a better measure of ozone forming potential than the correct mass based measurement of VOCs.

A recently released report from the National Research Council (NRC), Ozone Forming Potential of ,

Reformulated Gasoline, concluded that there is no compelling scientific basis at this time to recommend that ozone forming potential or reactivity replace mass of emissions in the RFG program. A change from the mass of emissions approach to a reactivity approach would not impact the choice of one fuel over another from the standpoint of air quality benefits.

The NRC report found that fuel oxygen content appears to have only a small effect on the ozone forming emissions of RFG with reductions in CO emissions and in exhaust emissions of VOCs but with some evidence of increases in NO, emissions. The NRC did not examine the contribution of oxygenates to the emissions of air toxics.

The NRC report found that the contribution of CO to ozone formation should be recognized in assessments of the effects of RFG. The NRC committee found that CO emissions account for 15 percent to 25 percent of the reactivity of exhaust emissions from light duty vehicles and should be included in reactivity assessments because despite its low reactivity adjustment factor, the large mass of CO emissions contributes to ozone formation.

B. Ethanol Blend Commingling with MTBE and Hydrocarbon Blends An RVP43 increase of approximately one pound per square inch (psi) is caused by the addition of ethanol to a hydrocarbon base fuel. M As a result, all ethanol blended RFG is now blended with base gasoline that has had certain high RVP components, such as pentanes and butanes, reduced in order to ensure that ethanol blended RFG meets RVP requirement^.^^

42 (... continued) emitters. Because only one LEV was tested, statistical significance cannot be determined.

43 Reid vapor pressure is a measure of the gas pressure a liquidgas system will apply to a closed system when heated to 100 degrees Fahrenheit. As such, RVP is a measure of a liquid's volatility (i e ., its tendency to evaporate).

44 The size of increase in RVP is clearly affected by other factors, including the hydrocarbon makeup and original volatility characteristics of the blend into which the ethanol is added.

45 EPA has promulgated a program controlling the RVP of conventional gasoline on a nationwide basis. (See 40 CFR 80.27.) This program allows for a 1.0 psi exemption for 10 percent ethanol blends. Thus, if this program requires that RVP not'exceed 9.0 psi for a given area, 10 percent ethanol blends are allowed at RVPs of up to 10 psi. This exemption for ethanol blends does not apply to the RFG program.

35 Traditional thinking would conclude that when an ethanol blend is commingled with a non ethanol blend in a consumers tank, one would see a resulting RVP greater than would be expected from a simple volume weighted linear combination of the two blends' RVPs, at least if a sufficient amount of the ethanol blend were to be present. Thus, in a 50 50 commingled blend, where 10 percent ethanol gasoline with an RVP of 8.0 psi is added to an all hydrocarbon gasoline with the same 8.0 psi RVP, the resulting blend has an RVP of about 8.5 psi and not 8.0 psi as would be expected when non ethanol blends are commingled.

Commingling these two blends is equivalent to first combining the hydrocarbon portion of both blends and then adding the ethanol from the first blend to the combined hydrocarbon components. The hydrocarbon gasoline by definition has an RVP of 8.0 psi. The hydrocarbon portion of the ethanol gasoline had to have an RVP of 7.0 psi (since the subsequent addition of the ethanol produced an ethanol gasoline with an RVP of 8.0 psi). The hydrocarbon components combine linearly producing a new hydrocarbon component having an RVP of about 7.5 psi (half way between 7.0 and 8.0 psi). 46 Then, adding in the ethanol component, which would now be about 5 percent of the final blend, increases the RVP of the final blend to about 8.5 psi. It is important to note that although the new 50 50 commingled blend wouid have an ethanol level of around 5 percent, not 10 percent as in the original ethanol blend, the full 1 .O psi RVP increase due to ethanol addition would still occur even at this lower ethanol Although this scenario does accurately describe the basic principles involved in volatility changes when these types of gasolines are blended, the reality is somewhat more complicated. The presence of less polar oxygenates like MTBE can decrease the volatility bump to some degree when more polar oxygenates like ethanol (e. g., as an ethanol blend) are added. This mechanism is called cos~ lvency.~~ One recent study on the impact of ethanol blend commingling concluded in part that an RVP bump of slightly greater than one psi occurs when ethanol is added at a two volume percent level in an all hydrocarbon blend, but that a bump of 0.7 psi occurs when ethanol is added to an MTBE blend at the same original RVP In addition to the expected RVP increase, many other factors are extremely important in determining the effect of commingling. These include ethanol blend market share, statiodbrand loyalty, and the distribution of fuel tank levels before and after a refueling event. Caffrey and Machiele attempted to take these variables into account in modeling the effect of ethanol blend commingling in a mixed fuel marketplace. Their conclusions include the following:

(1) Brand loyalty and ethanol market share are much more important variables than the distribution of fuel tank levels before and after a refueling event.

46 The final RVP resulting from the combination of these two hydrocarbon components would actually be slightly higher than 7.5 psi since the volume of the hydrocarbon portion of the ethanol gasoline is less than the volume of the hydrocarbon gasoline by an amount equal to the volume of the ethanol component.

47 These are approximations in order to demonstrate basic blending patterns. The volatility of blends resulting from commingling are not necessarily exact linear interpolations of the volatilities of the commingled blends.

48 Peter Caffiey and Paul Machiele, "In Use Volatility Impact of Commingling Ethanol and Non Ethanol Fuels," SAE Technical Paper #94065, February 29, 1994. See also, "The Octamix Waiver," 53 FR 3636, February 8, 1988.

49 Peter Caffrey and Paul Machiele, "In Use Volatility Impact of Commingling Ethanol and Non Ethanol Fuels," SAE Technical Paper #94065, February 29, 1994.

36 (2) Commingling effects can cause a significant increase in fuel RVP.

(3) Commingling effects are clearly more dramatic in a market in which a significant portion of the gasoline is all hydrocarbon (i. e. , non oxygenated). Depending on the combination of variables chosen (Le., especially ethanol market share), the RVP increase over the entire gasoline pool can range from around 0.1 to 0.3 psi in a reformulated gasoline market (ie., ethanol blends commingled only with MTBE blends). Analogous increases for a non reformulated market (i. e., ethanol blends commingled only with all hydrocarbon blends) range from under 0.1 psi to over 0.4 psi.

(4) The effects of the increase in RVP commingling approaches a maximum when the ethanol market share becomes 30 to 50 percent, and declines thereafter as ethanol takes a larger market share.

C. Fuel Quality in Conventional Gasoline Conventional gasoline is controlled under EPA's Anti Dumping Program. When the reformulated gasoline (RFG) regulations were introduced, an anti dumping program was also introduced. Refiners (and importers) were required to provide information on CG to show that its properties become no worse than they were in 1990. This program was meant to prevent refiners from simply removing "bad" blendstocks from RFG and dumping these into CG. In order to show that properties of CG would not deteriorate, refiners established individual 1990 baselines for CG, which were independently audited and submitted to the EPA. Refiners who could not establish a baseline because of insufficient available information were required to adopt the Clean Air Act baseline included in the statute. (Most parties believe that the Clean Air Act baseline is actually more stringent than a typical individual refinery baseline.)

However, there is no assurance that CG air toxics benefits gained since 1990 will be protected. The EPA's 1997 refinery survey data indicates that 1997 CG sold in the Northeast was 12.8 percent less toxic than 1990 levels. The data also indicate an additional 3.5 percent VOC reduction in the Northeast over the 1990 levels. 50 Under the complex model, refiners must not exceed their 1990 baselines for exhaust toxics and NO,. Although EPA does collect information on the quality of CG, the first data on complex model CG (from 1998) were not required to be submitted to EPA until May 3 1, 1999. The analysis of that data will take at least several months. Thus, at this time the EPA does not have current data on whether complex model CG toxics is in overcompliance. The Agency has indicated, however, that this analysis would be a critical element of guaranteeing that future increase in emissions potential will not occur in CG. Once the analysis is completed, EPA should review any regulatory or administrative authorities available to prevent deterioration of the current air quality performance of conventional gasoline.

If MTBE use was phased out, the antidumping program would prevent any increase in CG from 1990 NO, and toxics levels only. However, should MTBE be eliminated and ethanol use increase in CG, Department of Energy (DOE) modeling shows a 6 to 7 percent VOC increase in conventional gasoline due to the one pound waiver for ethanol use outside RFG areas. Regarding MTBE use in CG, the Energy Information Administration (EIA) data show that very little MTBE is actually used in conventional NESCAUM, Relative Cancer Risk of Reformulated Gasoline and Conventional Gasoline Sold in the Northeast, August 1998.

37 ga~ oline;~ ' estimates range, however, from 4,000 to 25,000 barrels per day. It should be noted that the anti dumping program would not prevent increases in MTBE use in CG.

EPA is also pursuing other initiatives that are related to the quality of CG. EPA has proposed a gasoline sulfur program and, if any form of sulfur control program were adopted nationally, NO, levels in CG would clearly be better than current level^. '^ The Agency is also in the process of evaluating mobile source air toxics and is expected to issue a proposal in early 2000, at which time the Agency will further address the issue of toxic emissions.

V. Wintertime Oxyfuel Program A. Introduction In addition to the RFG program, the CAAA of 1990 required the establishment of a Wintertime Oxyfuel program. Under this program gasoline must contain 2.7 percent oxygen by weight during the wintertime in areas that are not in attainment for the National Ambient Air Quality Standards for CO.

In 1992, when the oxygenated fuels program began, there were 36 areas implementing the program. The 1998 99 oxygenated fuels season had 17 areas implementing the program. Nineteen areas were able to redesignate to CO attainment due to the implementation of the oxygenated fuels program along with other control measures. Of the remaining 17 areas, eight have data to redesignate and are either working on or have submitted redesignation requests to EPA, or they have chosen to continue to implement the program as a CO control measure even though they have attained the standard. Six areas are classified as "serious" CO nonattainment areas, and the remaining three areas are classified as "moderate" CO nonattainment areas; all of these areas continue to implement the program in an effort to attain the CO standard.

Most of the winter oxygenated fuel areas use ethanol. The only two areas using MTBE for the winter oxygenate program are Los Angeles and the New York City metropolitan area. It is a possibility that New York City, which includes metropolitan Connecticut, New Jersey, and New York, will leave the program before the next winter season because they will demonstrate attainment with the CO standard. Los Angeles will need to phase out MTBE use under the Governor's recent directive. Therefore, MTBE use for winter oxygenated areas is not likely to be common in the future.

'' U. S. Energy Information Administration (Aileen Bohn and Tancred Lidderdale), Demand and Price Outlook for Phase 2 Reformulated Gasoline, 2000, April 1999. Data indicate that 5 thousand barrels per day oxygenate demand for conventional gasoline.

'* The Panel is aware of the current proposal for further changes to the sulfur levels of gasoline and recognizes that implementation of any change resulting from the Panel's recommendations will, of necessity, need to be coordinated with implementation of these other changes. However, a majority of the Panel considered the maintenance of current RFG air quality benefits as separate from any additional benefits that might accrue from the sulf'ur changes currently under consideration.

38 B. Air Quality Benefits The most comprehensive study regarding oxygenated fuels was completed in June 1997 by the Office of Science and Technology Policy (OSTP). 53 The report concluded that "analyses of ambient CO measurements in some cities with winter oxygenated fuels programs find a reduction in ambient CO concentrations of about 10 per~ ent." '~ The report also suggested "the need for a thorough, statistically defensible analysis of ambient CO data." In response to that suggestion, EPA initiated a study55 that analyzed ambient CO data from about 300 monitoring sites. The study indicated a downward shift in ambient CO ranging from 6 percent to 13 percent for the six month winter season in areas implementing an oxyfuel program in 1992. This EPA study was further refined by Systems Applications International (SAI). 56 The SA1 study analyzed summer (June and July) and winter (December and January) bimonthly means or maximum daily 8 hour CO concentrations from 1986 to 1995. The report concluded that there was a substantial (14 percent reduction) and statistically significant association (k 4 percent with 95 percent confidence) between the use of oxyfuels and monitored CO concentrations. '

On this point, the OSTP report concluded:

Older technology vehicles (carbureted and oxidation catalysts) benefit more from the use of oxygenated fuel. The amount of pollutant emissions is smaller in newer technology vehicles (fuel injected and adaptive learning, closed loop three way catalyst systems). Additionally, the percentage reductions in CO and hydrocarbon emissions from the use of fuel oxygenates are found to be smaller in the newer technology vehicles compared to older technology and higher emitting vehicle^. '^

Analysis by the EPA (MOBIL6 Model) also indicates that even with fleet turnover, a significant contribution to CO reduction from the winter oxygenated program is expected until at least 2005 (Table 3).

'' Office of Science and Technology Policy, National Science and Technology Council, Interagency Assessment of Oxygenated Fuels, June 1997.

54 Office of Science and Technology Policy, National Science and Technology Council, Interagency Assessment of Oxygenated Fuels, June 1997, p. iv.

55 US. Environmental Protection Agency, Office of Mobile Sources, (R. Cook), Impact of the Oxyfuel Program on Ambient CO Levels, 1996.

Systems Application International, Regression Modeling of Oxyfuel Efects On Ambient CO Concentrations, January 1997.

39 '' Office of Science and Technology Policy, National Science and Technology Council, Interagency Assessment of Oxygenated Fuels, June 1997, p. iv. Table 3. Percent Reduction in CO Emissions Resulting from 3.5 Percent Oxygen, As Predicted by the MOBILE Model5*

Year MOBILE6 1997 10% to 20%

2000 5% to 15%

2005 0% to 10%

2010 0% to 2%

Source: U. S. Environmental Protection Agency Most winter oxygenated areas use ethanol, which is typically blended at 3.5 percent by weight. Therefore the chart reflects actual benefits rather than the benefits that may result from the regulatory requirement of 2.7 percent oxygen by weight. If a lower oxygen level is used, one would expect there to be a linear downward trend in benefits.

The U. S. Environmental Protection Agency's Area by Area analysis of 1998 RFG Survey Data indicates that the complex model emissions performance of RFG in Chicago and Milwaukee, while easily exceeding all Phase I performance (i e ., emission reduction) requirements, generally ranks low compared to other RFG areas. In order to investigate factors influencing the performance of Chicago and Milwaukee RFG relative to RFG in other areas, it is necessary to consider the composition of the fuels. The Chicago and Milwaukee property values were similar, and there were notable differences from the National Average properties. The sulfur and benzene levels for Chicago and Milwaukee were substantially higher. These two areas had the highest and second highest levels of all areas for these parameters. Oxygenate type and oxygen content differed from the National Average. Ethanol was the primary oxygenate used in these areas. Therefore, the total oxygen content and the ethanol contribution to, total oxygen were highest for these areas. Olefin content was lower than the National Average RFG, and the olefin content for these two areas was the lowest of all areas surveyed.

The higher sulfur levels in the Chicago and Milwaukee RFG affected its relative complex model performance for all three pollutants. This analysis indicates that sulfur was the primary factor influencing relative VOC and NOx performance, and that it may have some influence on toxics performance. Although 1998 RFG Survey Data indicates that the complex model emissions performance of RFG in Chicago and Milwaukee, easily exceeded all Phase I performance (ie., emission reduction) requirements. The margin of air toxics overcompliance was not as great there as in other areas primarily due to higher benzene content, but other factors such as increased acetaldehyde emissions and sulfur levels also contributed. Oxygenates had little impact on VOC or NO, performance.

'* MOBILE6 effects are draft only. Only after MOBILE6 is finalized will actual and more accurate estimates be available. These projected MOBILE6 Oxy on CO effects are based on MOBIL Report #M6. FUL. 002, which is posted on the MOBILE6 web site (htt~:// www. e~ a. gov/ OMS/ M6. htm.)

40 It is important to realize that this analysis was intended to identify factors which caused Chicago and Milwaukee to rank lower than most other RFG areas in complex model emissions performance. The approach was to vary one property at a time and look at its effect on emissions performance. In reality, fuel properties are not independent, and this "one at a time" analysis was not intended to answer more complex questions such as "What would happen to fuel properties and emissions performance if Chicago and Milwaukee RFG suppliers switched from ethanol to MTBE?"

41 Y U 1111 0 P W (n . s i s t 1 C. Prevention, Treatment, and Remediation I. In trod uction This Issue Summary reviews the technical and regulatory approaches to reducing the sources of oxygenate impacts on water resources; release prevention and detection; storage tank related issues; Federal and State approaches to protecting drinking water sources; the treatment of impacted drinking water; the remediation of oxygenate impacted ground water; and funding sources. Because of recent detections of methyl tertiary butyl ether (MTBE) in drinking water supplies, MTBE is emphasized throughout this section. The body of information available to evaluate impacts of other gasoline oxygenates on water resources is significantly more limited.

The water resources described in this section are generally divided into two categories: surface water (streams, lakes, reservoirs, and stormwater); and ground water (water table and confined aquifers). Drinking water refers to those water resources currently used for public and private water supply systems. Although a variety of sources of MTBE impacts to water quality have been identified, this section focuses primarily on releases from underground storage tank (UST) systems, as this population comprises the vast majority of the known potential point sources and has been studied in much greater detail than other potential sources of MTBE impact.

II. Sources and Trends of Water Quality Impacts As described in Issue Summary A (Water Contamination), surface water and ground water resources are impacted by both gasoline oxygenates and a variety of other natural and anthropomorphic sources of contaminants. There are a number of primary sources that appear to be responsible for most identified MTBE impacts:

8 Underground storage tanks, other gasoline storage and distribution facilities, such as bulk storage terminals, small householdlfarm gasoline tanks, and aboveground storage tanks;

8 Interstate and intrastate petroleum pipelines;

Small releases (e. g., gasoline tank ruptures during car accidents or consumer 8 disposal of gasoline in backyards) appear to have been the source of private well contamination in Maine. 59 These types of releases are also expected to be a source of contamination to private wells in other States;

8 Engine exhaust and related releases (e. g., spillage) into lakes and reservoirs from two stroke watercraft and older four stroke watercraft;

8 Stormwater runoff.

59 State of Maine Bureau of Health, Department of Human Services, Bureau of Waste Management & Remediation, Department of Environmental Protection, Maine Geological Survey, and Department of Conservation, Maine h4TBE Drinking Water study, The Presence of MTBE and other Gasoline Compounds in Maine's Drinking Water Preliminary Report, 1998.

45 A. Assessing Impacts and Trends There are no comprehensive quality assessments of our nation's water' resources that can provide clear indications of the trend of MTBE impacts on water supplies. Further, it is unknown how frequently gasoline compounds are released from the current population of UST systems or the quantity of gasoline that is released. As such, it is unknown whether releases of gasoline and related impacts to water resources are continuing to grow, whether increasing awareness of this issue has stabilized or reduced the frequency of such releases, or whether they are on the decline. Not all States require monitoring for MTBE at LUFT sites and in drinking water quality sampling, further preventing a full characterization of MTBE's current or potential future impacts.

New Federal and State UST regulations promulgated in the 1980's have spurred comprehensive assessments and corrective action programs at facilities with USTs. As of December 1998, many currently regulated UST facilities can be expected to have had some type of site assessment conducted as part of compliance activities and property transfer information requirements in order ro determine whether there have been any releases. The number of identified UST releases has grown steadily during the last decade, averaging about 20,000 new known releases annually.@ Most releases have been discovered with tank removal during the tank upgrading process, rather than being detected as part of a continuous monitoring program. Thus, it is not possible to know when the release actually occurred (e. g., many releases reported in 1998 occurred in previous years, bLt were only discovered in 1998). The rate at which new release sites are discovered is expected to decrease in coming years, as most UST facilities being evaluated for contamination were in the process of meeting the December 1998 upgrading deadline. Because of timitations inherent in current leak detection technologies, it is expected that releases reported in future years from the current population of upgraded facilities will not provide a more accurate characterization of the occurrence of new releases.

Limited information is available regarding releases from other gasoline storage/ distribution facilities, and very little data exist to characterize the extent to which other types of gasoline releases occur.

B. Underground and Aboveground Storage Tanks Underground storage tanks represent the largest population of potential point sources of gasoline releases to ground water. 61 Gasoline storage and distribution facilities are of particular importance as potential sources of ground water contamination from MTBE and other oxygenates, because these facilities can release relatively large volumes of gasoline (e. g., hundreds of gallons to thousands of gallons), which can result in localized subsurface impacts with aqueous concentrations in excess of 100,000 parts per billion (ppb) adjacent to the release source, as well as extensive dissolved plumes at lower concentrations. In California, MTBE (associated with gasoline releases throughout the State) is a frequent and widespread contaminant in shallow groundwater. Detections of MTBE are reported at 75 percent of sites where fuel hydrocarbons have impacted ground water. The minimum number of MTBE point sources from leaking underground storage tank (LUST) sites in California is estimated at greater than 10,000. Maximum concentrations at these sites ranged from several ppb to concentrations greater th& 100,000 ppb, indicating a wide range in the magnitude of MTBE impacts at these sites (Table 1).

eo U. S. Environmental Protection Agency, Office of Underground Storage Tanks, `` Corrective Action Measures Archive," httr, :// www. eaa. rrov/ swerust 1 /catfcamarchv. htm.

61 US. Environmental Protection Agency, Office of Water, National Water Quality Inventory: 1996 Repor? to Congress, 1 996.

46 Table I. Comparison of Maximum MTBE Ground Water Concentrations Collected by the California Regional Boards, January 1999 MTBE Concentration Sites Exhibiting Concentration (Parts Per Billion) Level (Percent)

<5 5 50 50 200 23%

12%

11%

200 1,000 17%

1,000 5.000 5,000 20,000 20,000 100,000 14%

13%

7%

Note: Data represent collections from 4,300 sites. Source: Happel, Dooher, and Beckenbach, "Methyl Tertiary Butyl Ether impacts to California Groundwater,` presentation at the March I999 MTBE Blue Ribbon Panel meeting.

There are currently an estimated 825,000 regulated USTs at approximately 400,000 facilitie~.~~ Of the nation's approximately 182,000 retail gasoline outlets, the "major" oil companies own about 20 percent, or about 36,000 fa~ ilities. 6~ On average, each of the nation's retail outlets have about 3 storage tanks, thus containing a total of approximately 550,000 USTs, 66 percent of the national total. The remainder of the regulated UST population consists of state or federally owned facilities and nonretail fueling facilities (e.&, on site fueling for taxis, rental cars, delivery trucks, etc.). Over the past 10 years, approximately 1.3 million Federally regulated USTs have been closed, i. e., removed or properly emptied, cleaned, and buried in place. 64 There are approximately 3 million underground fie1 storage tanks exempt from Federal regulations (e. g., certain farm and residential gasoline tanks and home heating oil tanks (ASTs) at refineries and distribution terminals, however, are regulated under both State and Federal laws, including the Spill Control and Countermeasures (SPCC) regulations of the Oil Pollution Act (OPA) of 1990. There are currently over 10,000 facilities with this type of bulk storage of gasoline. As compared with USTs, there is no comparable Federal regulatory program for ASTs, and thus current Large aboveground storage U. S. Environmental Protection Agency, Office of Underground Storage Tanks, based upon FY 1999 Semi Annual Activity Report  First Hav( unpub1ished).

`' National Petroleum News, Market Facts 1998 (Arlington Heights, IL: Adams Business Media, 1998), p. 124.

There is no database that identifies the specific locations of these federally regulated facilities or their proximity to drinking water supply sources. See U. S. Environmental hotection Agency, Office of Underground Storage Tanks, "Corrective Action Measures Archive," httD:// www. eDa. gov/ swerust l/ cat/ camarchv. htm.

" U. S. Environmental Protection Agency, Underground Heating Oil And Motor Fuel Tanh Exempt From Regulation Under Subtitle I Of The Resource Conservation And Recovery Act (May 1990).

47 m , release statistics for ASTs are not available. A 1994 American Petroleum Institute (API) survey estimated that ground water contamination had been identified at approximately 68 percent of marketing terminals with ASTs, 85 percent of refinery tank fields with ASTs, and 10 percent of transportation facilities with ASTs. Of these facilities, over 95 percent were engaged in corrective action under the guidance of a State or Federal authority. 66 C. Pipelines Excluding intrastate pipelines and small gathering lines associated with crude oil production fields, there are approximately 160,000 miles of liquids pipelines in the United States6' These pipelines transport approximately 12.5 billion barrels of crude oil and refined products annually. Over a recent six year period (1993 to 1998), an average of 197 spills occurred annually, with an average volume from ali spills totaling 140,000 barrels per year. Of the volume spilled during this period, crude oil accounted for 44 percent, whereas refined petroleum products (e. g., gasoline, home heating oil, jet fuel) accounted for 3 1 percent. Although the specific volume of gasoline spilled cannot be readily identified, gasoIine represents the largest volume of refined products transported. Additionally, there are little or no data on the extent of MTBE releases from pipelines.

In California, pipeline release data are currently being compiled by the Oflice of the State Fire Marshal, which regulates approximately 8,500 miles of pipelines. Since 1981, there have been approximately 300 pipeline releases within the State Fire Marshal's Jurisdiction.

The pipeline industry is working with pipeline regulators and environmental trustee agencies to develop a definition of areas that may be unusually sensitive to environmental damage from pipeline leaks to be used in conducting future risk assessments along pipeline rights of way. Included under the draft definition are areas with drinking water resources, which are based on EPA's standards €or defining both surface and subsurface drinking water supplies. Once work is completed both on drinking water and biological resources that may be unusually sensitive to environmental damage, OPS will make information available for pipeline operators to use in conducting risk assessments along pipeline rights of way. The Office of Pipeline Safety may also require increased pipeline integrity standards to prevent releases in unusually sensitive areas. 68 In California, the locations of fuel pipelines and drinking water wells are being integrated into a geographic information system (GIs), which is discussed in greater detail in Section V of this Issue Summary. The State Fire Marshal Ofice is required at least once every two years to determine the identity of each pipeline or pipeline segment that transports petroleum products within 1,000 feet of a public drinking water well. Furthermore, these pipelines' operators must be notified to prepare a pipeline wellhead protection plan for the State Fire Marshal's approval.

66 American Petroleum Institute, A Survey of API Members ' Aboveground Storage Tank Facilities, July 1994.

`' The U. S. Department of Transportation (Don's Office of Pipeline Safety (OPS) oversees the safety and environmental regulation of interstate petroleum pipelines. Petroleum pipelines are also subject to economic regulation by the Federal Energy Regulatory Commission (FERC).

Development of the definition and its subsequent application are subject to notice and comment requirements under Federal rulemaking procedures.

48 D. Small Releases Small releases from automobile accidents, consumer disposal of "old" gasoline, or other backyard spills during fueling operations have been identified by officials in Maine as sources of contamination of private drinking water wells. For example, in a 1998 study of over 900 private household drinking water wells in Maine, approximately 16 percent had detectable MTBE concentrations, and about 1 percent contained concentrations exceeding the State of Maine's 35 ppb drinking water In one incident in Maine, about 7 to 12 gallons of gasoline spilled during a car accident contaminating 24 nearby private wells installed in a bedrock aquifer. Eleven of the wells had MTBE concentrations in excess of 35 ppb. Following the excavation of the contaminated soil, well monitoring at this site has indicated that MTBE levels are decreasing rapidly in all wells. Similarly, home heating oil storage tanks have also been identified as potential sources of MTBE contamination, as MTBE might be present from mixing the heating oil with small volumes of gasoline in the bulk fuel distribution or tank truck delivery systems. 70 E. Watercraft Gasoline powered watercraft have contributed to the contamination of lakes and reservoirs with MTBE. These impacts are primarily attributed to exhaust discharges from two stroke engines, which are the most commonly used engine type in such watercraft. The two stroke engines discharge in their exhaust up to 30 percent of each gallon of gasoline as unburned hydrocarbons. In two recent studies examining MTBE contamination at lakes at which reformulated gasoline (WG) with MTBE was used, concentrations of MTBE in substantial portions of the lakes' volume ranged from 10 ppb to 30 ppb after peak periods of recreational watercraft usage. 71 After the boating season ended, these concentrations decreased fairly rapidly (half life of approximately 14 days) to low background levels (approximately 1 ppb to 2 ppb or less). Volatilization is considered the dominant mechanism for this removal proce~ s. '~

F. Stormwater Runoff Stormwater runoff is considered a nonpoint source of MTBE contamination. Runoff becomes contaminated with MTBE from both the dissolution of residual MTBE from parking lots (e. g., service 69 State of Maine Bureau of Health, Department of Human Services, Bureau of Waste Management & Remediation, Department of Environmental Protection, Maine Geological Survey, and Department of Conservation, Maine MTBE Drinking Water Stu&, The Presence of MTBE and Other Gasoline Compounds in Maine's Drinking Water Preliminary Report, 1998.

'O G. A. Robbins et al., "Evidence for MTBE in Heating Oil," Ground Water and Remediation, Spring 1999, pp. 65 68. ... 71 M. S. Dale et al., "MTBE  Occurrence and Fate in Source Water Supplies," in American Chemical Society Division of Environmental Chemistry preprints of papers, 2 13th, San Francisco, CA: American Chemical Society, v. 37, no. 1, 1997, pp. 376 377; J. E. Reuter et al., "Concentrations, Sources, and Fate of the Gasoline Oxygenate Methyl Tert Butyl Ether (MTBE) in a Multiple Use Lake," Environmental Science & Technology, 1998, v. 32, mo. 23, pp. 3666 3672.

72 J. E. Reuter et al., L` Concentrations, Sources, and Fate of the Gasoline Oxygenate Methyl Tert Butyl Ether (MTBE) in a Multiple Use Lake," Environmental Science & Technology, 1998, V. 32, mo. 23, pp. 3666 3672.

49 stations and retail businesses) and roadways and from "atmospheric MTBE contamination from atmospheric washout is thought to be small compared to that from paved surfaces. 74 The United States Geological Survey (USGS) has characterized MTBE concentrations in runoff in many areas and has typicaIly found such contamination to be lower than 2 ppb. Stormwater is discharged both to surface water and to ground water, and thus serves as a source of very low level MTBE contamination of these potential drinking water sources.

III. Refease Prevention and Detection A. Prevention Since the passage of Federal UST legislation in 1984, improved release prevention practices (e. g., corrosion protection, and compatibility between the tank's construction materials and its contents) has been required for all new USTs. Following a I O year phase in period from the promulgation of EPA regulations in 1988, as of December 1998, all regulated USTs are required to be protected from corrosion, small spills, and overfills, and must also have release detection equipment and procedures in place. Many States have additional and more stringent standards. These regulations are intended to prevent releases, and should a release occur, to detect it promptly in order to minimize ground water impacts. Presently, it is not possible to demonstrate the effectiveness of individual States' UST upgrade programs or the Federal upgrade program in preventing releases of gasoline from dispensinghtorage facilities.

Even after tank systems (tanks and piping) are in full compliance with the 1998 regulations, however, some releases are expected to occur as a result of improper installation or upgrading, improper operation and maintenance, and accidents. Many of these releases may not be detected as intended due to the inherent limitations of release detection technologies.

Anecdotal reports from California, Maine, and Delaware indicate that upgraded USTs continue to have releases. Efforts are underway by the EPA and in California to evaluate new and upgraded UST systems to determine which factors may contribute to such releases. In CaIiforniq, for example, the Santa Clara Valley Water District has completed a study evaluating release prevention and detection performance at approximately 30 upgraded facilities. 75 The California Environmental Protection Agency (CalEPA) is planning to begin a similar study in 1999. Further studies will likely be required in order to investigate a representative sampling of the UST population.

'3 G. C. Delzer et al., Occurrence of the Gasoline Oxygenate MTBE and BTEXCompounds in Urban Stormwater in the UnitedStates, 1991 95, US. Geological Survey Water Resources Investigation Report WRIR 96 4 145,1996.

74 A. L. Baehr, P. E. Stackelberg, and R. J. Baker, `` Evaluation of the Atmosphere as a Source of Volatile Organic Compounds in Shallow Ground Water," Water Resources Research, Jan. 1999, v. 35, no. I , pp. 127 136; T. J. Lopes and D. A. Bender, "Nonpoint Sources of Volatile Organic Compounds in Urban Areas  Relative Importance of Urban Land Surfaces and Air," Environmental Pollution, 1 998, v. 10 1 , pp. 22 1 230.

75 Santa Clara Valley Water District Groundwater Vulnerability Pilot Study, "Investigation of MTBE Occurrence Associated with Operating UST Systems," July 22, 1999. http:// www .scvwd. dst. ca. us/ wtrcpal/ factmtbe. htm.

50 Based on reports received to date from the States, EPA estimates that approximately 80 percent of the regulated universe of UST systems currently meet the December 1998 requirement^.^^ By the end of 2000, EPA expects at least 90 percent of the regulated tanks will be in compliance, leaving approximately 80,000 tanks that have not been upgraded. States' UST programs are primarily responsible for implementing and enforcing UST regulations. In augmenting and assisting States' activities? EPA provides outreach, helps States train UST inspectors, and fosters the exchange of information among States regarding effective means of securing compliance. Upon a State's request, or acting independently when necessary, EPA will also take direct action to enforce the regulations.

Approximately 20 States now prohibit deliveries to UST systems that are not fully compliant with the December 1998 regulations, and several major gasoline suppliers have stopped fuel delivery to non compliant tanks. These actions, along with the traditional enforcement actions taken by EPA and States, have contributed to higher compliance rates. 77 The U. S. Environmental Protection Agency and the States also require that USTs that do not meet the technical standards are properly closed with thorough site assessments for potential releases. Through December 29, 1999, non compliant USTs can be temporarily closed, but must be permanently closed, and any releases identified and remediated, thereafter if not brought into compliance.

Currently? there is an apparent trend toward using small ASTs (ie., fewer than 20,000 gallons) to replace regulated USTS.~~ These ASTs are generally not subject to the same release prevention and detection requirements as USTs. Releases from ASTs may also result in MTBE contamination, and so it may be necessary to evaluate the performance of such systems.

13. Detection Existing regulations require the use of release detection techniques that meet specific performance criteria. Internal (e. g., automatic tank gauges) or external (e. g., ground water monitoring) approaches may be used in meeting these criteria. Although these regulations do not allow any detected releases to go unreported, the regulations do permit several options of varying degrees of sensitivity in the detection of a release, which can result in smaller releases going undetected for an extended period of time. 79 The regulations, promulgated in 1988, were considered adequate and "best available technology" for typical gasoline (and other fuels) formulations at the time because hydrocarbon plumes are generally self

'` U. S. Environmental Protection Agency, Ofice of Underground Storage Tanks, estimate based upon data submitted by States on February 28, 1999 and April 30, 1999 (unpublished).

'' Ellen Frye, "When Push Comes to Shove," LUSTLine, September 1998.

jug^ Sexton, Kansas State Department of Health & Environment, paper presented at the 10' Annual USTLUST National Conference (Long Beach, CA, March 30, 1999); Wayne Geyer, LLAbove the Ground but not the Law: ASTs on the Rise, Regulators in Hot Pursuit," Petroleum Equipment and Technology, July 1999.