the rule justify the costs. Assessing the costs of a new proposed standard is a somewhat more straightforward exercise than evaluating benefits but complicated, involving estimates of the total national costs that will be incurred by water utilities to comply with a new standard. Estimating the benefits of a proposed rule involves gaining an understanding of the health effects attributable to various levels of the contaminant and the benefits of reducing these risks.

EPA charged the National Academy of Sciences (NAS) with providing expert advice on the health impacts of arsenic based upon a comprehensive assessment of national and international studies. The NAS provided quantitative (numerical) recommendations concerning the risk of bladder cancer to consumers of drinking water containing arsenic. The NAS also provided qualitative (non-numeric) recommendations concerning a number of other potential adverse health effects of concern, the most significant of which is lung cancer. In evaluating the benefits of a new, more protective arsenic standard in drinking water, the Agency has examined both quantitative and qualitative benefits. Ascribing values to such benefits is a challenging exercise that involves an element of judgment, based on an array of data and information. Discussion and resolution of these issues has been an important part of this process—and, as is the case in any such complicated undertaking, experts can and often do differ in their respective evaluations. While there has been internal debate on these cost-benefit issues, this is not unusual in a significant rulemaking. Discussion has been encouraged and development of the rule has benefited. When it is proposed, we will solicit comment on our estimates of the costs and benefits of the rule and on the underlying issues of concern.

MTBE

Question 5. I am concerned about MTBE in our groundwater. State officials in New Hampshire say that as many as 7,000 private wells could be contaminated with unsafe levels of MTBE and as many as 33,330 could be contaminated with lower trace levels. It seems that we didn't use good science when we decided to put MTBE in our gasoline and now it has created another even bigger problem. What is EPA doing to address MTBE in groundwater?

Response. In response to the growing concerns regarding MTBE, in early 1999 Administrator Browner appointed an independent Blue Ribbon Panel to investigate the use of oxygenates in gasoline. On July 27, 1999, the Panel issued its recommendations. Specifically the Panel:

Recommended improvements to the nation's water protection programs, including over 20 specific actions to enhance underground storage tank, source water and drinking water, and private well protection programs.-Agreed broadly that use of MTBE should be reduced substantially and that Congress should act to provide clear Federal and state authority to regulate and/or eliminate the use of MTBE and other gasoline additives that threaten water supplies.-Recommended that Congress act to remove the current Clean Air Act requirement that 2 percent of RFG, by weight, consist of oxygen-to ensure that adequate fuel supplies can be blended in a cost-effective manner while reducing usage of MTBE; and Recommended that EPA seek mechanisms to ensure that there is no loss of current air quality benefits. EPA is working with Congress, the states and the regulated community to implement the Blue Ribbon Panel's recommendations and address the problem of MTBE in groundwater:

We will work with Congress to quickly phaseout MTBE while preserving a market for renewable fuels and maintaining clean air benefits.

EPA is currently evaluating all of its regulatory options under existing statutory authorities for addressing the contamination of groundwater from MTBE.

year.

A new drinking water standard for MTBE will be proposed within the next

MTBE is included in the Unregulated Contaminant Monitoring Rule. This rule requires all large and a representative sample of small public water systems to monitor for MTBE in ground water and surface water beginning in 2001. EPA is strongly encouraging water systems to begin monitoring as soon as possible.

EPA is developing maps of State Underground Storage Tanks (USTs) that can be compared with water source locations to help assess the actual risk of potential leaking USTs to public water supplies.

EPA is working with States to develop an operation and maintenance manual that will help improve the safety of UST systems and is conducting workshops around the country with State water program officials for UST owners and operators.

· EPA allocated $1 million for demonstration projects to determine the most effective approach to MTBE remediation. MTBE remediation research efforts also cur

rently are underway by other organizations, such as the American Petroleum Institute and the University of California at Davis.

Prior to MTBE's use in Federal RFG, a consent agreement under the Toxic Substances Control Act required industry to conduct extensive research of MTBE. The MTBE research included short and long term animal inhalation studies that did not point to any exceptional acute or chronic toxicity. In the early 1990's, human chamber studies on acute exposure to pure MTBE were completed by EPA, the Centers for Disease Control, and industry. The studies provided strong evidence that MTBE alone was not likely to cause acute health effects in the vast majority of the general population. Additional inhalation research that includes testing of baseline conventional gasoline and nonbaseline groups including gasolines with MTBE and other oxygen additives is underway. It is hoped that the results of this inhalation research can be extrapolated and allow a greater understanding of MTBE ingestion health risks.

While additional research will add to our understanding of the health effects of MTBE, action to prevent further MTBE contamination of water supplies should not await the results of this research. Due to its persistence and mobility in water, MTBE is more likely to contaminate ground and surface water than other components of gasoline. Indeed, according to EPA's Blue Ribbon Panel, MTBE has already been found in up to 10 percent of drinking water supplies in RFG areas. To prevent the escalation of a larger problem, EPA believes the use of MTBE should be quickly phased out.

UST

Question 6. What is the status of EPA's enforcement of the 1998 deadline for compliance with the UST regulations?

Response. EPA and the states worked together to coordinate our enforcement strategy following the December 1998 deadline. As the primary implementing agencies, states pursued the majority of the inspections and enforcement actions related to the deadline. In the first 6 months immediately following the deadline, EPA focused its enforcement resources on facilities that posed a threat to drinking water or sensitive ecosystems; Federal facilities; large, multiple UST facilities; and owners and operators with multiple facilities. Thereafter, EPA broadened its enforcement efforts to all facilities that remained in noncompliance.

At the end of fiscal year 1999, 85 percent of the approximately 760,000 active federally regulated underground storage tanks (USTs) were in compliance with the 1998 deadline requirements. We expect the compliance rate will be 90 percent by the end of fiscal year 2000.

Question 7. Do you know the percent of people (who) are in compliance with the 1998 regulations?

Response. We do not have data on compliance rates by facility owner, only by UST system. As you may know, an owner or operator may have multiple UST tanks. Almost all states are the primary implementing agencies for the UST program, and the states maintain the data bases that contain the notification and compliance information. The compliance data reported by the states is for UST systems, not for facility owners.

Question 8. Where is EPA targeting enforcement resources?

Response. Since the states are the primary implementing agencies for the UST program, they perform the vast majority of inspection/enforcement work in the program. States use a wide variety of methods for targeting their resources, often focusing on wellhead protection areas or other sensitive environmental areas. In addition, EPA also targets facilities in areas where a state can not provide an active enforcement presence as well as facilities referred to us by the states.

In the first 6 months immediately following the 1998 deadline, EPA focused its enforcement resources on facilities that threatened sources of drinking water or sensitive ecosystems; federally owned facilities; large, multiple UST facilities; and owners and operators with multiple facilities. Although these facilities remain an enforcement priority, EPA has since broadened its enforcement efforts to all facilities that remain in noncompliance.

Question 9. Have you looked at the extent of leaking in those tanks that have come into compliance with the 1998 regulations?

Response. Assessing the performance of compliant UST systems is one of the highest priorities for the Office of Underground Storage Tanks (OUST). This includes measuring the effectiveness of our leak detection requirements, as well as studying the release rate from compliant tanks, and identifying the cause of those releases (e.g., faulty installation, failed overfill device, release from piping). A number of states and EPA regions are beginning to record this data at all new release

sites. In addition, EPA is funding a study with the University of California at Davis to assess the effectiveness of various leak detection methods.

However, based on anecdotal data from the states we know that petroleum releases have occurred from UST systems that had met the requirements of the 1998 deadline. In addition, a preliminary assessment of California's UST data base by the University of California at Davis indicates that the annual leak rate for UST systems that comply with upgrading requirements was 0.07 percent per year, compared to approximately 3 percent per year for all active tanks. It is reasonable to assume that a certain number of releases will continue to occur from systems with new or upgraded UST systems due to improper installation, improper operation and maintenance, or accidents. Ensuring proper operation and maintenance is another of OUST's highest priorities.

High Production Volume Chemical Testing Program

Question 10. In October 1999 an agreement was reached between EPA and animal rights groups to address many of the concerns raised regarding the EPA High Production Volume Chemical Testing Program ("HPV Program"). Although an agreement has been reached, I am concerned about how the program will be implemented in a manner consistent with the agreement. In December 1999 animal rights groups petitioned EPA to issue two rules which would require chemical companies to file existing data and information on HPV chemicals prior to initiating new testing under the HPV program. Has the October agreement been embodied in.the Inventory Update Rule?

Response. The animal welfare principles outlined in the October 14 letter from EPA to HPV Challenge participants are incorporated, to the fullest extent possible, in the proposed High Production Volume (HPV) Chemical Test Rule currently under review at OMB. EPA encourages the fullest possible use of existing data in order to minimize the need for new testing. Once this proposed rule is promulgated, the public will have an opportunity to comment on all aspects of the rulemaking including issues related to animal welfare. The Inventory Update Rule (IUR) is a separate rulemaking unrelated to the HPV Challenge Program and was not addressed by the October 14 letter. The recently proposed IUR amendments do not require any testing. The IUR Amendments, which were proposed on August 26,1999(64 FR 46771), would call upon companies to assemble and report existing exposure and use data for their chemicals under the Toxics Substances Control Act (TSCA).

Question 11. If the purpose of the program was to gather toxicity data on those chemicals most commonly used in our country, why does a citizen group need to petition EPA to issue rules to carry out the primary purpose of the program?

Response. In the HPV Challenge Program, the Agency has worked successfully in partnership with industry to establish a voluntary program to make this information available to the public. To date, this voluntary approach has yielded commitments from industry to provide the needed data on nearly 2100 of 2800 high production volume chemicals. As part of this program, EPA has intended to pursue a TSCA test rule for those chemicals which are not voluntarily sponsored by industry. Under Section 21 of the TSCA, citizens may petition EPA to initiate a proceeding for the issuance, amendment, or repeal of a rule under various other sections of TSCA. In this instance, the petitioners assert that a voluntary approach to collecting basic screening level toxicity information on HPV chemicals will not be effective in bringing forward all relevant existing data. They have thus called for a rulemaking approach to compel the disclosure of that information.

Question 12. Does EPA intend to issue such rules?

Response. EPA published a Federal Register notice (65 FR 2164, January 13, 2000) reporting that the petition had been filed and solicited public comments by February 3, 2000. Under Section 21 of TSCA, EPA must respond to the petition by March 28, 2000. The Agency is currently evaluating the petition and the comments received, and has not yet responded to the petition.

MTBE

Question 13. The EPA is currently considering a waiver of the Clean Air Act's 2 percent oxygen mandate for the State of California. We are working on legislation to address this issue, but I want to encourage the EPA to give the California waiver full consideration. California uses more gasoline containing MTBE than any other state and they are quite concerned with the effect this might have on water supplies. Can you give this committee any sense of the status of the California waiver petition?

Response. We share California's desire to keep the State's drinking water free of MTBE and other contaminants. EPA's goal is to protect public health and the environment by ensuring Americans have both cleaner air and cleaner water—and never

one at the expense of the other. On December 24, 1999, California officials provided EPA initial documents in support of the state's waiver request. EPA is reviewing this initial information and stands ready to receive additional data the state is gathering that is necessary to complete its request.

On January 25, 2000, staff from the California Air Resources Board (CARB) and the EPA met to discuss the additional data and analysis necessary for a waiver to be considered. CARB has indicated that it will supply this additional information to EPA. Once EPA receives this information from CARB, EPA will be able to perform the technical analysis of California's waiver request required under the Clean Air Act. If the statutory requirements to receive the waiver are met, EPA is required to provide public notice of our decision. Such procedures include a public comment period of a minimum of 30 days.

Utilities Emissions Bill

Question 14. Recently, I announced the start of a process to develop legislation to improve how the Clean Air Act addresses pollution from the electric utility sector. Developing a bill on this topic that will have broad bipartisan support is going to be an enormous challenge. I would hope that the EPA will work with my staff in an open and creative way as we all search for a more efficient system to deal with these pollutants. If we can build on the Acid Rain model, I believe that we can improve the environmental results of our efforts—while at the same time lowering the implementation costs for industry, the economy, and the government.

Response. As you examine this issue, EPA will, as always, be happy to work with you and your staff.

Yucca Mountain

Question 15. NAS and NRC have recommended that standards for Yucca Mountain be based on sound radiation protection science (i.e., do not use old ICRP 2 dose methods in setting standards). NRC has an overall approach for setting regulatory limits that involves: 1) setting an overall goal for protection applicable to all regulated activities (i.e., 100 mrem public dose limit); 2) developing dose limits for particular activities (e.g., waste disposal) that are consistent with the overall goal; and 3) updating dose limits, as necessary, to make use of scientific improvements for estimating dose. EPA's approach for setting radiation standards is not as clear. Although, EPA generally uses an overall risk goal (i.e., lifetime risk between one chance in 10,000 and one chance in 1,000,000), EPA has and continues to set radiation limits that have little relationship to this overall goal (i.e., MCLs) and have recently proposed standards for Yucca Mountain (40 CFR 197) based on outdated methods for estimating dose.

Can EPA explain, what appears to be, significant inconsistencies and weaknesses in their approach for setting radiation standards? What interactions has EPA had with the NRC and NAS to address their comments?

Response. The EPA's proposed Yucca Mountain standards are entirely consistent with other standards the Agency has established and, in almost every respect, are consistent with the recommendations of the NAS. In all its regulatory programs, the Agency typically establishes risk in the 10-6 to 10-4 range (1 chance in a 1,000,000 to 1 chance in 10,000). This is the Agency's guideline for establishing radiation regulations for involuntary risks over and above background levels. EPA's generic standards for spent nuclear fuel and high-level waste and the Agency's proposed standards for Yucca Mountain assure protection of at least 15 millirem/year. The lifetime fatal cancer risk associated with this dose is approximately 3 chances in 10,000.

With respect to EPA's proposed standards for drinking water, EPA proposed to adopt the Agency's 4 millirem/yr dose limit for Maximum Contaminant Level (MCL) standards under the Safe Drinking Water Act. The lifetime fatal cancer risk associated with this dose is 1 chance in 10,000.

For Yucca Mountain, the National Academy of Sciences (NAS) suggested a risk level equivalent to an annual dose in the range of 2 to 20 millirem/yr. The annual risk associated with EPA's proposed 15 millirem standard and 4 millirem standard for drinking water fall within this range. The 25 millirem/yr dose limit proposed by the NRC would allow greater risk than that recommended by NAS. NAS has supported EPA's proposed 15 millirem standard. In its November 26, 1999 comments on the 15 millirem standard, NAS stated that "the magnitude of the proposed numeric value of the individual-protection standard is consistent with the recommendations in the [NAS] report.'

We realize that science has improved in the 20 years since the Maximum Contaminant Level (MCL) standards for drinking water were established and we are working to update them based on current scientific understanding and legislative

direction under the Safe Drinking Water Act Amendment. All changes will be incorporated by reference in EPA's final Yucca Mountain standards.

We have made and will continue to make every effort to consider all of the issues which have been brought to our attention by the NRC, NAS, and other interested parties. Both NRC and NAS have submitted written comments on EPA's proposed standards. EPA will work closely with NRC and NAS to address their comments in EPA's final standards.

RESPONSES BY MICHAEL MCCABE TO ADDITIONAL QUESTIONS FROM SENATOR CRAPO Yucca Mountain/Nuclear Regulatory Commission

Question 1. Both the Environmental Protection Agency (EPA) and Nuclear Regulatory Commission (NRC) have promulgated radiation exposure standards for a geologic repository, better known as Yucca Mountain, for the nation's spent nuclear fuel and high-level waste. The establishment of a permanent repository is of paramount importance to the ability of the Department of Energy and Department of Navy in meeting a court-ordered agreement with the State of Idaho. Legislation currently in the Senate, S.1287, would identify the NRC as the standard-setting Agency for a geologic repository, not the EPA. This proposal recognizes that the NRC is the nation's expert in dealing with radiation and is supported widely and bipartisanly in Congress. Is there any reason to expect that the NRC would not be capable of setting standards for the geologic repository that will protect public health and the environment?

Response. The Energy Policy Act of 1992 gave EPA responsibility for setting the standards for a repository at Yucca Mountain and NRC responsibility for determining whether or not the repository meets the standards through a licensing process. This arrangement of having EPA set the standards and NRC implement them is how nuclear facilities have been regulated for the past 30 years. This is the system of checks and balances that was established when EPA was formed in 1970.

While NRC is expert in the licensing of nuclear power plants, EPA was designated by Congress to set the safety standards for Yucca Mountain. EPA has the expertise to set appropriate health and safety standards for the disposal of radioactive waste and has done so for decades. EPA also has expertise in implementing such standards successfully. In fact, EPA set the safety standards for, and certified, the only operating geologic repository for permanent disposal of radioactive waste in the United States-the Waste Isolation Pilot Plant in New Mexico.

In addition, EPA has a wealth of experience in setting standards for, and licensing, hazardous waste facilities. This has informed our proposed Yucca Mountain standard. Our Yucca Mountain proposal was designed to achieve the same level of protectiveness, an increased risk in the 10-6 to 10-4 range (1 chance in a million to 1 chance in 10,000), as all these other Agency standards.

NRC has issued draft standards for Yucca Mountain. These draft NRC standards do not include specific protections for potable groundwater and would allow a greater risk to individual members of the public (25 millirem/yr dose limit vs. EPA's proposed 15 millirem/yr dose limit). Based on these draft standards and NRC comments and statements of intent, EPA believes that EPA's standards will more adequately protect public health and the environment than NRC standards.

Question 2. The EPA has been criticized for dragging its feet on issuing radiation standards for the geologic repository. The Agency finally issued radiation standards on August 19, 1999. The EPA does not appear to be promulgating needed standards in the timeframe that is needed to make the repository a reality. Why did it take the EPA so long to issue these standards? If the EPA remains the standard-setting organization for the repository, what changes will you make to ensure the EPA is responsive to necessary standards development?

Response. EPA recognizes that these standards are very important for assuring the safety of any repository at Yucca Mountain. This project involves a unique facility with many complex technical issues. EPA has made every effort to consider all of the issues which have been brought to our attention. This includes meetings with interested parties and discussions within the Administration. A significant amount of this time was spent addressing scientific issues in coordination with the National Academy of Sciences, the Administration's Office of Science Technology and Policy, the Department of Energy (DOE) and the Nuclear Regulatory Commission. EPA has worked diligently to resolve the many complex issues. Additional time taken was necessary to ensure that we prepared standards that were technically sound, legally defensible, could be reasonably implemented, and were protective of public health and the environment.