Opinion ID: 492030
Heading Depth: 1
Heading Rank: 4

Heading: do epa's regulations violate the safe drinking water act?

Text: 43 Part C of the Safe Drinking Water Act, 42 U.S.C. Sec. 300h (1982) (SDWA), indicates that the EPA has a duty to assure that underground sources of drinking water will not be endangered by any underground injection. Petitioners argue here that endangerment of such drinking water is bound to result if HLW is disposed of, underground, under standards no more stringent than the EPA's current HLW regulations. Since violations of the SDWA are inevitable, so petitioners argue, the present regulations are not in accordance with law and hence invalid. 44 To understand this argument we must first look at the SDWA, an Act which preceded the NWPA. The SDWA was enacted in 1974 to assure safe drinking water supplies, protect especially valuable aquifers, 8 and protect drinking water from contamination by the underground injection of waste. The SDWA required the EPA to promulgate standards to protect public health, by setting either (1) maximum contaminant levels for pollutants in a public water supply, or (2) a treatment technique to reduce the pollutants to an acceptable level if the maximum contaminant level is not economically or technologically attainable. Maximum contaminant levels are to be established at a level having no known or adverse human health effect, with an adequate margin for safety. 42 U.S.C. Sec. 300g-1(b)(1)(B). The EPA has established maximum contaminant levels for man-made radionuclides, see 40 C.F.R. Sec. 141.16, as well as a maximum contaminant level for naturally occurring radium, see 40 C.F.R. Sec. 141.15. 45 These standards apply to public water systems which regularly supply water to 15 or more connections or to 25 or more individuals at least 60 days per year. 42 U.S.C. Sec. 300f(4); 40 C.F.R. Sec. 141.1(e). The public water system has the responsibility to make sure the water it supplies meets these limits. In effect, the community water system must either clean up existing water if below standard, or find a new water supply which meets the maximum contaminant levels. The EPA is given certain powers to enforce its standards. 42 U.S.C. Sec. 300g-3(b). 46 The SDWA also authorizes EPA to designate, on its own initiative or upon petition, an area as having an aquifer which is the sole source of the area's water supply and which would create a significant hazard to public health if contaminated. Once an area is so designated, no federal assistance may be provided for any project in the area which EPA determines may contaminate the aquifer. See 42 U.S.C. Sec. 300h-3(e). 47 The SDWA's only provision for directly regulating pollution-causing activities is found in Part C, 42 U.S.C. Sec. 300h. There Congress sought to protect underground sources of drinking water from what are termed underground injections. Underground injection is the subsurface emplacement of contaminating fluids 9 by well injection. 42 U.S.C. Sec. 300h(d)(1). Part C requires the EPA to promulgate regulations governing underground injection control programs. 48 The EPA is directed to publish a list of each state for which an underground injection control program would be necesary to assure that underground injection would not endanger drinking water sources. 42 U.S.C. Sec. 300h-1(a). The EPA has listed all states as needing underground injection control programs. 40 C.F.R. Sec. 144.1(e). 49 The EPA is also required to promulgate regulations governing state underground injection control programs to ensure that the state programs prevent underground injection which could endanger drinking water sources. 42 U.S.C. Sec. 300h(a)(1), (b)(1). If a state program does not comply with the EPA's regulations, the EPA itself is to promulgate a regulatory program for that state and enforce compliance. 42 U.S.C. Sec. 300h-1(c). To be approved by EPA, a state control program has to meet certain standards. It must prevent underground injection unless authorized by permit or rule; it may authorize underground injection only where it is demonstrated that the injection will not endanger drinking water sources; and it shall include inspection, monitoring, recordkeeping and reporting requirements. 42 U.S.C. Sec. 300h(b)(1)(A)-(C). State regulatory programs (as well as any EPA regulations for non-complying states) apply to underground injections by federal agencies as well as all others. 42 U.S.C. Sec. 300h(b)(1)(D). 50 In requiring EPA to regulate state underground injection control programs, Congress restrained the EPA's authority in several ways in order to accommodate existing state programs and avoid disrupting oil and gas production. EPA's regulations may not interfere with or impede the production or recovery of oil or natural gas, unless such requirements are essential to assure that underground sources of drinking water will not be endangered by such injection. 42 U.S.C. Sec. 300h(b)(2). EPA's regulations are to reflect the variations in geologic, hydrological or historical conditions between the states. 42 U.S.C. Sec. 300h(b)(3)(A). To the extent feasible, EPA is not to promulgate rules which unnecessarily disrupt state underground injection control programs that were earlier in effect. 42 U.S.C. Sec. 300h(b)(3)(B). Congress made it clear, however, that, despite the deference the EPA was to afford the states, the goal of protecting underground drinking water was to be preeminent. The SDWA states, 51 Nothing in this section shall be construed to alter or affect the duty to assure that underground sources of drinking water will not be endangered by any underground injection. 52 42 U.S.C. Sec. 300h(b)(3)(C). This language in particular, petitioners say, establishes that the EPA has an overriding statutory mandate, unaffected by the NWPA, to protect underground drinking water against endangerment. 53 The SDWA defines what is meant by the term endanger: 54 Underground injection endangers drinking water sources if such injection may result in the presence in underground water which supplies or can reasonably be expected to supply any public water system of any contaminant, and if the presence of such contaminant may result in such system's not complying with any national primary drinking water regulation or may otherwise adversely affect the health of persons. 55 42 U.S.C. Sec. 300h(d)(2). 56 Petitioners assert that the EPA, in promulgating the HLW standards, has violated this so-called no endangerment mandate because its rules will allow underground injections that result in radiation contamination of underground drinking water supplies. 57 Analysis of petitioners' argument requires us to address several questions: (1) whether storage of HLW in underground repositories will constitute an underground injection as that term is used in the SDWA; (2) whether the EPA's HLW standards sanction activities that will endanger drinking water, as that phrase is used in the SDWA; and (3) whether, if the two previous questions are answered in the affirmative, EPA's HLW regulations are contrary to law or, if not, are nonetheless arbitrary and capricious. We shall deal with each of these questions in turn. 58 (1) Does Storage Of HLW In Underground Repositories Constitute Underground Injection? 59 What petitioners call the no endangerment provision of the SDWA, 42 U.S.C. Sec. 300h(b)(3)(C), indicates that the EPA has a duty to assure that underground sources of drinking water will not be endangered by any underground injection. For the Agency to have violated that duty by adopting the present HLW regulations, it is necessary that the proposed placing of HLW in underground repositories constitute an underground injection. The SDWA defines underground injection as the subsurface emplacement of fluids by well injection. 42 U.S.C. Sec. 300h(d)(1) (emphasis added). The EPA, in its regulations enacted pursuant to the SDWA, has defined the terms fluids and well injection. 60 Well injection is the subsurface emplacement of fluids through a bored, drilled or driven well; or through a dug well, where the depth of the dug well is greater than the largest surface dimension. 40 C.F.R. Sec. 146.3. 61 The Department of Energy, in its Mission Plan, has described how the HLW will be disposed of underground. The HLW will be removed from transportation casks, packaged and then transferred underground through the waste-handling shaft. Once underground, the wastes will be emplaced in boreholes.... Mission Plan at 33. Thus it seems that waste will be emplaced underground through a bored, drilled or driven shaft. 62 The EPA has defined the term fluids broadly as including a material or substance which flows or moves whether in a semi-solid, liquid, sludge, gas or any other form or state. 40 C.F.R. Sec. 146.3. This definition was taken directly from the legislative history which made it clear that [t]he definition of 'underground injection' is intended to be broad enough to cover any contaminant which may be put below ground level and which flows or moves, whether the contaminant is in semi-solid, liquid, sludge, or any other form or state. H.R.Rep. No. 1185, 93d Cong., 2d Sess., reprinted in 1974 U.S.Code Cong. & Admin.News 6454, 6483. The definition of high level waste in the NWPA shows that at least some of the waste material to be disposed of originates in a liquid form. 63 The term high-level radioactive waste means-- 64 (A) the highly radioactive material resulting from the reprocessing of spent nuclear fuel, including liquid waste produced directly in reprocessing and any solid material derived from such liquid waste that contains fission products in sufficient concentrations.... 65 42 U.S.C. Sec. 10101(12). According to the EPA, the waste to be stored underground will be converted, before storage underground, into a solid. See Background Information Document at 3-4. This does not mean that the contemplated waste disposal system is not an underground injection, since the definition of fluids (following the directive in the legislative history, see supra ) is very broad and includes waste in any other form or state if it flows or moves. 40 C.F.R. Sec. 146.3. The dangerous component of this waste, i.e., the radiation, regardless of whatever form or state it is emitted from, will flow or move, thus having the capacity to do harm to drinking water sources far distant from the original site as more conventional injected fluids would do. The HLW waste rules apply to radionuclides that are projected to move into the 'accessible environment' during the first 10,000 years. See Preamble, 50 Fed.Reg. 38,071, col. 2. The definition of barrier in the regulations includes a structure which prevents or substantially delays movement of water or radionuclides toward the accessible environment. 40 C.F.R. Sec. 191.12(d). 66 The Arizona Nuclear Power Project, et al., intervenors in this case, argue that disposal of this radioactive waste underground is not the type of underground disposal that Congress was concerned with when it enacted Part C of the SDWA. Intervenors claim that the type of underground injection which disturbed Congress was a method whereby contaminants were injected into the subsurface and allowed to disperse freely into the general environment. Intervenors assert that the type of disposal contemplated by the HLW rules is different because the waste will be packaged in containers, and will be surrounded by barriers that are designed to isolate this waste from the environment. Thus, they conclude, Part C does not apply to this disposal system. 67 While Congress may have been especially concerned with a different type of underground disposal when it passed Part C of the SDWA, this does not negate its overall intent to protect future supplies of drinking water against contamination. Unusable ground water is unusable ground water no matter whether the original source of the pollution arrived in a loose, free form manner, or in containers injected into the ground. We find no language in the SDWA showing that Congress meant to regulate only certain forms of underground pollution, while overlooking other forms of contamination of ground water via underground injection. Indeed, the legislative history indicates that the phrase underground injection which endangers drinking water sources was to have the broadest applicability: 68 It is the Committee's intent that the definition be liberally construed so as to effectuate the preventative and public health protective purposes of the bill. The Committee seeks to protect not only currently-used sources of drinking water, but also potential drinking water sources for the future.... 69 The Committee was concerned that its definition of endangering drinking water sources also be construed liberally. Injection which causes or increases contamination of such sources may fall within this definition even if the amount of contaminant which may enter the water source would not by itself cause the maximum allowable levels to be exceeded. The definition would be met if injected material were not completely contained in the well, and if it may enter either a present or potential drinking water source, and if it (or some form into which it might be converted) may pose a threat to human health or render the water source unfit for human consumption. 70 H.R.Rep. No. 1185, 93d Cong., 2d Sess., reprinted in 1974 U.S.Code Cong. & Admin.News at 6484. 71 We believe that the narrow and constrained reading of Part C of the SDWA advocated by intervenors would do violence to the intent of Congress. We decline that reading. 72 We conclude that the primary disposal method being considered, underground repositories, would likely constitute an underground injection under the SDWA. 73 (2) Do The Regulations Under Review Sanction Activities That Will Endanger Drinking Water? 74 Part C of the SDWA, 42 U.S.C. Sec. 300h(b)(3)(C), speaks of the EPA's duty to assure that underground sources of drinking water will not be endangered by any underground injection. (Emphasis supplied.) Assuming, as discussed above, that the planned disposal of HLW in underground repositories amounts to underground injection, will such injection, if carried out under the EPA's current HLW standards, endanger underground sources of drinking water? We believe the answer is yes. 75 As noted, the term endanger is defined in the SDWA to include any injection which may result in the presence in underground water which supplies or can reasonably be expected to supply any public water system of any contaminant ... if the presence of such contaminant may result in such system's not complying with any national primary drinking water regulation. 42 U.S.C. Sec. 300h(d)(2). Measured against this definition, the HLW standards permit contamination of most categories of underground water within the so-called controlled area without restriction of any type. More fundamentally, they permit water supplies outside the controlled area to be contaminated by radiation up to individual exposure levels that exceed the levels allowed in national primary drinking water regulations. It follows that the HLW regulations under review not only do not assure the non-endangerment of underground sources of drinking water, but sanction disposal facilities allowing certain levels of endangerment as that term is used in the SDWA. We shall now discuss our conclusions in greater detail.
76 The two major components of the HLW rules, the general containment requirements and the individual protection requirements, supra, set limits on radiation releases to every part of the earth, including ground water, beyond the area under direct control of those in charge of disposing of this waste (referred to as the controlled area). These requirements have various release limits (depending on which rule is involved, i.e., the limits of the general containment requirements are of a different type from those of the individual protection requirements) which apply outside the controlled area, but neither sets limits on contamination of ground water within the controlled area. A further component, the special source ground water protection requirements, sets limits on releases to certain ground water supplies found within the controlled area, or within five kilometers of the controlled area. However, this rule applies to only a very special class of ground water. 77 Thus, while the ground water outside the controlled area is covered by both the general containment requirements and the individual protection requirements (the sufficiency of which we shall later address), there is essentially no protection of ground water within the controlled area (other than the specific ground water rule, infra, with its highly limited applicability). This is because the general containment and individual protection requirements apply only to releases to the accessible environment. The accessible environment is defined as (1) the atmosphere; (2) land surfaces; (3) surface waters; (4) oceans; and (5) all of the lithosphere that is beyond the controlled area. 40 C.F.R. Sec. 191.12(k). Lithosphere is defined as the solid part of the earth below the surface, including any ground water contained within it. 40 C.F.R. Sec. 191.12(j). Controlled area is defined as: (1) A surface location, to be identified by passive institutional controls, that encompasses no more than 100 square kilometers and extends horizontally no more than five kilometers in any direction from the outer boundary of the original location of the radioactive wastes in a disposal system; and (2) the subsurface underlying such a surface location. 40 C.F.R. Sec. 191.12(g). 78 Thus the two broadly applicable rules (general containment and the individual protection requirements) set some limits on radiation releases to every part of the earth, including the ground water, except within the controlled area, i.e., the part of the earth immediately surrounding the repository. This means that any ground water found within the controlled area (except the special water protected under the ground water protection requirements) may be contaminated without limit. The administrator has explained that the definition of accessible environment, 79 was intended to reflect the concept that the geologic media surrounding a mined repository are part of the long-term containment system, with disposal sites being selected so that the surrounding media prevent or retard transport of radionuclides through ground water. Such surrounding media would be dedicated for this purpose, with the intention to prohibit incompatible activities (either those that might disrupt the disposal system or those that could cause significant radiation exposures) in perpetuity. Applying standards to the ground water contained within these geologic media surrounding a repository would ignore the role of this natural barrier, and it could reduce the incentive to search for sites with characteristics that would enhance long-term containment of these wastes. 80 50 Fed.Reg. 38,077, col. 1. The administrator further explained that the accessible environmentdoes not include the lithosphere (and the ground water within it) that is below the controlled area surrounding a disposal system. The standards are formulated this way because the properties of the geologic media around a mined repository are expected to provide much of the disposal system's capability to isolate these wastes over these long time periods. Thus, a certain area of the natural environment is envisioned to be dedicated to keeping these dangerous materials away from future generations and may not be suitable for certain other uses. 81 50 Fed.Reg. 38,071, col. 2. Hence the regulations under review deliberately expose the ground water in the controlled area to contamination in the belief that the controlled area may appropriately be used in this manner to keep the dangerous high level wastes away from future generations. There can be little doubt, therefore, that the current HLW standard allows endangerment, as the term is used in the SDWA, of most kinds of drinking water sources in the controlled area. However, as we later discuss, the EPA's choice to sacrifice the purity of water at repository sites as part of the control strategy was impliedly sanctioned by Congress when, subsequent to passage of the SDWA, it enacted the Nuclear Waste Policy Act. We accordingly find no illegality. (Our conclusion in this regard is discussed in a later part of this opinion.) 82 While unlimited endangerment of most waters is thus allowed (albeit permissibly) within the controlled area, there is within the controlled area one special category of ground water which, as we have seen, receives special protection. The special source ground water protection requirements afford protection to Class I ground water of certain types in and close to (within five kilometers of) the controlled area. The ground water requirements limit the radionuclide concentrations in these Class I waters for 1,000 years to no more than concentration limits similar to those established for community water systems under the SDWA. That is, this standard sets limits that are compatible with the maximum contaminant level for man-made radiation set under the SDWA. Thus, when applicable, the special source ground water protection requirements comply with the no endangerment policy expressed in Part C of the SDWA since they exactly parallel the limits set by the EPA under the SDWA. However, the ground water protection requirements apply only to so-called Class I ground water (as defined in the EPA's Ground-Water Protection Strategy published in August 1984). In addition, they apply only to those Class I waters which also meet the following conditions: 83 (1) They are within the controlled area or near (less than five kilometers beyond) the controlled area; (2) they are supplying drinking water for thousands of persons as of the date that the Department [of Energy] selects the site for extensive exploration as a potential location of a disposal system; and (3) they are irreplaceable in that no reasonable alternative source of drinking water is available to that population. 84 Clearly, the applicability of the special source ground water protection requirements is very much restricted. Petitioners, indeed, make much of this. They assert that this rule violates the SDWA's no endangerment policy since it protects so limited a class of water within so small an area, omitting the great bulk of the nation's usable ground water. 85 But while petitioners are doubtless right concerning the narrow scope of this provision, their criticism fails to take account of the EPA's strategy of dedicating the geologic media within the controlled area (including any ground water found within such geologic media) to serve as a part of the containment mechanism. The EPA obviously intended the special source ground water rule to provide protection only to a small category of ground water deemed to be so valuable that it should not be used for containment purposes. As the Agency assumed that ground water within the controlled area will be part of the containment mechanism, and that therefore a direct limit on releases to ground water within the controlled area is an exception to the general approach, it is understandable that any ground water requirements within the controlled area would have a very limited applicability. 86 These ground water requirements will likely serve more as a deterrent to siting repositories at places containing valuable ground water resources of this description than as a protective mechanism at actual repositories (where the special ground water covered by the ground water rule is unlikely to be present). Moreover, the ground water requirements have no effect more than five kilometers beyond the controlled area. It follows that there will likely be no protection to ground water within an actual controlled area site.
87 We turn next to the larger issue of whether the HLW regulations permit endangerment as defined in the SDWA of underground drinking water sources beyond the controlled areas. As just discussed, the special source ground water requirements do not apply at all outside the repository site and five kilometers beyond. The individual protection requirements, however, while not a ground water rule as such, give a considerable measure of protection to ground water outside the controlled area. 10 88 The individual protection requirements are designed to protect individuals in the vicinity of a disposal system by setting annual individual exposure limits effective for 1,000 years. (This contrasts with the general containment release limits which are designed to reduce risks to the general population through standards which limit the cumulative release of radiation for 10,000 years anywhere in the accessible environment.) The Agency added the individual protection requirements because, although it felt that the general containment requirements would ensure that the overall population risks to future generations would be acceptably small, it also felt that individuals near the repositories might receive substantially greater exposure to radiation than the average person. While overall releases from a repository could be within the total cumulative release limits of the general containment requirements, there might be nearby localities where the radiation would be concentrated, and thus pose a substantial risk to some individuals. As the Agency explained in the preamble to the HLW rules: 89 Even with good engineering controls, some waste may eventually (i.e., several hundreds or thousands of years after disposal) be released into any ground water that might be in the immediate vicinity of a geologic repository. Since ground water generally provides relatively little dilution, anyone using such contaminated ground water in the future may receive a substantial radiation exposure (e.g., several rems per year or more). This possibility is inherent in collecting a very large amount of radioactivity in a small area. 90 50 Fed.Reg. 38,077, col. 3. To avoid this problem the Agency added the individual protection requirements. 91 The individual protection requirements limit the annual exposure from the disposal system to any individual member of the public for the first 1,000 years to no more than 25 millirems to the whole body, or 75 millirems to any organ. This limit applies outside the controlled area. Inherent in the individual protection requirements is an indirect protection of ground water because in assessing compliance with this requirement, all potential pathways of radiation from the repository to individuals must be considered, and the assumption must be made that an individual drinks two liters per day from any significant source of ground water outside the controlled area. A significant source of ground water is defined as any aquifer currently providing the primary source of water for a community water system, or any aquifers that satisfy five technical criteria. These criteria, according to the EPA, identify underground water formations that could meet the needs of community water systems in the future. See 50 Fed.Reg. 38,078, col. 3. 92 While the individual protection requirements thus provide a level of protection, they also tolerate levels of contamination of drinking water sources well in excess of primary drinking water standards established by EPA under the SDWA, thus permitting endangerment of such sources as defined in the SDWA. Pursuant to the SDWA, the EPA has established the maximum contaminant level for man-made radionuclides in drinking water. 42 U.S.C. Sec. 300g-1. Accordingly, drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year. 40 C.F.R. Sec. 141.16(a). With the exception of two specific radionuclides (Tritium and Strontium-90), the concentration of man-made radionuclides causing 4 millirems total body (or organ dose equivalents) is to be calculated on the basis of assuming that the individual will consume two liters of drinking water per day. 40 C.F.R. Sec. 141.16(b). 93 As set out, supra, drinking water supplies are to be considered endangered under the SDWA if the underground injection may result in the presence in underground water which supplies or can reasonably be expected to supply any public water system of any contaminant, and if the presence of such contaminant may result in such system's not complying with any national primary drinking water regulation. 42 U.S.C. Sec. 300h(d)(2) (emphasis supplied). Since the maximum contaminant level of four millirems was promulgated as a national primary drinking water regulation under the SDWA, and since the individual protection requirements (promulgated under the NWPA) allow an individual dose of 25 millirems, it follows that the individual protection requirements allow HLW to be disposed of under circumstances that, in time, may result in endangering underground sources of drinking water. 94 It can be argued that the individual protection requirements do not necessarily endanger ground water resources because the allowable exposure (25 millirems) might result through a pathway that does not include contamination of ground water supplies. There are several possible pathways that the EPA considers when assessing individual exposure. These possible pathways include direct releases to the land surface, releases through a river, releases to an ocean (then to ocean fish which man would ingest). See Background Information Document at Chapter 7. It is conceivable that an individual could receive only 2 millirem/year from underground drinking water sources and the remaining 23 millirems from a different pathway. This, theoretically, would not result in ground water contamination in violation of the no endangerment mandate, i.e., ground water would still be under four millirems. However, this scenario is highly unlikely. 95 In the preface to the HLW rules the EPA concedes that the geological and geochemical characteristics of appropriate sites tend to concentrate eventual releases of wastes in any ground water that is close to the site. Preamble, 50 Fed.Reg. 38,078. Moreover, the Agency admitted that even with very good engineered controls, radiation may eventually be released in ground water in the immediate vicinity of a repository. 50 Fed.Reg. 38,077, col. 2. The Agency states that anyone using such contaminated ground water in the future may receive a substantial radiation exposure (e.g., several rems per year or more ). 50 Fed.Reg. 38,077, col. 3 (emphasis supplied). Since a rem is equal to 1,000 millirems (a millirem equals one thousandth of a rem), a possible exposure level of several rems per year will equate to several thousand millirems. In view of the EPA's own references to substantial exposure through sources of drinking water, it seems clear that a large proportion of the allowable 25 millirems would reach the individual through the drinking water pathway. We note in this regard that the definition of endangerment, found in the SDWA, see 42 U.S.C. Sec. 300h(d)(2), does not require actual violations of primary drinking water standards but rather merely that underground injectionmay result in contamination in excess of the maximum contamination levels set forth pursuant to the Safe Drinking Water Act. 96 Nor is a violation of the no endangerment provision prevented by EPA's assertion, in the preamble to these rules, that the individual protection requirement in no way limits the future applicability of the Agency's drinking water standards (40 C.F.R. Part 141)--which protect community water supply systems through institutional controls. 50 Fed.Reg. 38,073, col. 2. Once HLW is placed in a repository, the situation may well be irreversible: there may be no feasible way, years later, to arrest ongoing contamination of surrounding water supplies. To be sure, if a community's water supply is contaminated above levels set in the SDWA, authorities may require that it be abandoned and a new source of supply used. But the EPA's duty under the SDWA is to ensure non-endangerment of underground sources of drinking water. 42 U.S.C. Sec. 300h(b)(3)(C). This cannot be done after the fact. 97 The individual protection requirements may allow endangerment of drinking water supplies in another way. The individual protections apply for 1,000 years, as compared to the general containment requirements, which apply for 10,000 years. Thus, after 1,000 years, exposures to individuals near the repositories are not regulated (other than to the extent that the generally applicable 10,000 year cumulative release limits regulate any releases near the repositories). Apparently the rule allows for virtually unlimited degradation of underground water supplies near the control area after 1,000 years. Thus, after 1,000 years, the no endangerment provision would be violated. Whether this is a permissible deviation is discussed below. We mention it in this section merely as a further way that the current rules may be said to permit endangerment. 98 We conclude that the individual protection requirements will permit repositories to be built and used for the disposal of HLW which will, judged by the stricter standard of the SDWA, endanger drinking water supplies. 99 (3) Does Noncompliance With SDWA Make The Regulations Contrary To Law Or Arbitrary And Capricious? 100 We have determined in sections (1) and (2) above that the challenged HLW regulations pertain to underground injection, and that the standards they provide will allow underground sources of drinking water to be endangered within the meaning of the SDWA. 101 We must now ask whether the foregoing conclusions cause the current regulations to be contrary to law or arbitrary and capricious. The EPA asserts that the no endangerment provision of the SDWA applies to the EPA only in its role as administrator under the SDWA. In its different role as regulator of the disposal of high level waste under the NWPA, the Agency argues that it is free to adopt standards different from the ground water standards established under SDWA. EPA also makes other arguments supporting the proposition that the SDWA is irrelevant to our review of the HLW standards. See infra. 102 In analyzing the relation between the SDWA's no endangerment provision and the HLW standards, we divide our discussion into two parts: (A) Non-compliance with the SDWA in the controlled area, and (B) Non-compliance outside the controlled area. 103 Briefly summarized, our conclusion in respect to (A) is that when enacting the Nuclear Waste Policy Act of 1982, 42 U.S.C. Secs. 10101-10226 (1982), Congress was aware that the area in immediate proximity to the buried HLW would likely be dedicated as a natural protective barrier, and hence could become contaminated. We read the NWPA as containing, by implication, authority for the EPA to depart from SDWA standards in any controlled area. It follows that insofar as the regulations under review permit radiation contamination of ground water located within the controlled area itself, they are not contrary to law nor do we find them to be arbitrary and capricious. 104 In respect to (B) our conclusion is different. We find no evidence that Congress expected the HLW standards to permit underground sources of drinking water outside the controlled area to be degraded to levels beneath the standards EPA had established under the SDWA. At very least, such permitted degradation, without any accompanying explanation showing a clear need or justification for a different and lower standard than the SDWA prescribes, is arbitrary and capricious. 105 We now discuss these matters in detail. 106 (A) Non-compliance With The SDWA In The Controlled Area 107 As we have pointed out above, the only protection for ground water within the controlled area comes from the special source ground water requirements. These requirements, however, only apply to specially defined Class I ground waters supplying drinking water for thousands of persons. It is quite likely that the ground water found in the controlled areas of actually selected repositories will not be of this type. Hence in the controlled area there will probably, as a practical matter, be no limits on the radioactive contamination of such ground water as is present. It follows that any ground water within the controlled area which is a source or potential source of drinking water will be subject to endangerment within the SDWA. 108 However, based on our reading of the Nuclear Waste Policy Act and its legislative history, we conclude that Congress did not expect that its prior no endangerment policy, as found in the SDWA, should be applied to ground water found within the controlled area, even assuming such water were a source or potential source of drinking water. 109 The NWPA sets out the requirements of the EPA's task. The administrator pursuant to authority under other provisions of law, shall, by rule, promulgate generally applicable standards for protection of the general environment from offsite releases from radioactive material in repositories. 42 U.S.C. Sec. 10141(a). The EPA's duty applies to releases offsite. We read the statute as allowing onsite releases, or at least as acknowledging that some releases onsite are inevitable. 110 The EPA has explained that the ground water within the controlled area is necessarily part of the geologic mechanism that is going to be used to contain these wastes. This view has some support in the legislative history. That history, unfortunately, provides little discussion of the EPA's duties beyond merely reiterating that the administrator is to promulgate general standards for protection of the general environment. H.R.Rep. No. 491, 97th Cong., 2d Sess. 57, reprinted in 1982 U.S.Code Cong. & Admin.News 3792, 3823. However, in its discussion of the Department of Energy's responsibility in selecting a site for a repository, the legislative history reveals that Congress knew that some contamination of ground water in the immediate vicinity of the radioactive material was inevitable. The House Report describes the Secretary of Energy's responsibility to 111 develop guidelines to be used in selecting sites qualified to merit in-depth study as possible repository sites. The primary feature of the site specifically to be evaluated consists of a rock medium about 1,000 or more feet underground which will of itself provide one of the primary containments of the waste. Some surface or associated geologic features are also important concerns in site selection. The Secretary is required to specify in the guidelines factors which would qualify or disqualify a site from development as a repository, including proximity to natural resources or populations, hydrogeophysics, seismic activity and nuclear defense activities. The Secretary is required to give priority to sites in rock which tend to slow down transportation of radionuclides by water. 112 1982 U.S.Code Cong. & Admin.News at 3816. Since Congress told the Department of Energy to give priority to sites in rock which tend to slow down transportation of radionuclides by water, it is clear that Congress knew of the inevitability of some contamination of ground water in the immediate area of the stored waste. Had Congress intended that there be no contamination of ground water in the immediate vicinity, it would have required that the DOE select rock formations that would stop the transportation of radionuclides by water, rather than merely giving priority to rock formations that slow down the spread of radionuclides by water. 113 Further support for the EPA's approach can be found in the EPA's duties under the Act. The EPA's responsibility is pursuant to authority under other provisions of law. 42 U.S.C. Sec. 10141(a). The other provisions of law that are referred to are found in the Reorganization Plan No. 3 of 1970, 3 C.F.R. Sec. 1072 (1966-70 compilation), which was the method, within the executive branch, for organizing the newly created EPA in 1970. The reorganization plan transferred to the EPA the 114 functions of the Atomic Energy Commission under the Atomic Energy Act of 1954, as amended, administered through its Division of Radiation protection standards, to the extent that such functions of the Commission consist of establishing generally applicable standards for the protection of the general environment from radioactive material. As used herein, standards mean limits of radiation exposures or levels, or concentrations or quantities of radioactive material, in the general environment outside the boundaries of locations under the control of persons possessing or using radioactive material. 115 Reorganization Plan No. 3 of 1970, Sec. 2(a)(6), 3 C.F.R. Sec. 1073. See Quivira Mining Co. v. EPA, 728 F.2d 477 (10th Cir.1984) (reorganization plan effectively transferred Atomic Energy Commission's authority to EPA). 116 This definition of the parameters of the general environment to be protected by EPA further supports the view that Congress intended that the EPA only regulate releases beyond the controlled site. Since Congress knew that some ground water contamination is unavoidable and since Congress also knew that the EPA was working under this definition of the general environment (i.e., outside the boundaries of locations under the control of persons possessing or using radioactive material), it would be irrational and illogical to assume that Congress expected the EPA to set standards that would prohibit or severely limit all releases to the ground water within the controlled area, especially as Congress acknowledged that some releases are inevitable. We have previously said, [w]e would be loath to construe the [Clean Air] Act as requiring the Administrator to do the impossible. NRDC v. EPA, 478 F.2d 875 (1st Cir.1973). 117 Moreover, if Congress disagreed with this definition of the general environment from the reorganization plan (which defined the duties of the EPA), Congress would not have used the same terminology (i.e., the term general environment) that was used in the reorganization plan. This view is further bolstered by the language of the NWPA itself, which required the EPA to protect the general environment from offsite releases. 42 U.S.C. Sec. 10141(a). Since EPA's duty only applies to protect against offsite releases, Congress implicity allowed or at least expected releases onsite. 118 Finally, we note that the SDWA was enacted in 1974. The NWPA was enacted in 1982. As Congress knew that this nuclear waste could not be disposed of underground without some onsite contamination of ground water, and given the existence of the no endangerment policy of the SDWA, we are faced with conflicting statutory mandates. Using familiar statutory interpretation, when there is such a conflict, the most recent and more specific congressional pronouncement will prevail over a prior, more generalized statute. See 2A C. Sands, Sutherland on Statutes and Statutory Construction Sec. 51.02 (4th ed. 1984). True, repeals by implication are not favored, Morton v. Mancari, 417 U.S. 535, 551, 94 S.Ct. 2474, 2483, 41 L.Ed.2d 290 (1974); nonetheless, within the controlled area, we think the two statutes are irreconcilable. Id. at 550, 94 S.Ct. at 2482 (only permissible reason for finding of repeal by implication is when earlier and later statutes are irreconcilable). Congress ordered that these highly dangerous wastes be placed underground with the intent that the surrounding geologic formations would be the major component of the containment mechanism. Since Congress knew that such underground disposal will inevitably contaminate some ground water, we cannot read the NWPA as intending that any ground water found within the geologic formations, acting as a containment mechanism, must be kept at drinking water quality. We conclude that Congress meant to override SDWA's no endangerment policy for releases onsite, and therefore the no endangerment provision does not apply to potential drinking water sources within the controlled area. This being so, the endangerment of these onsite waters is not contrary to law nor, obviously, would it be arbitrary and capricious, given the administrator's reasoned explanation that contamination of this relatively small area is an essential part of his plan for protecting the outside environment. 119 (B) Non-compliance In The Accessible Environment 120 Outside the controlled area, we have much greater difficulty with EPA's arguments seeking to justify a standard which permits the radioactive contamination of sources of drinking water at levels higher than the same agency has deemed acceptable for public water supplies under the SDWA. We are told to read possibly conflicting statutes so as to give effect to each if we can do so while preserving their sense and purpose. Watt v. Alaska, 451 U.S. 259, 267, 101 S.Ct. 1673, 1678, 68 L.Ed.2d 80 (1981). 121 The EPA asserts that Part C of the SDWA does not impose a substantive no endangerment duty upon the Agency. The EPA asserts that the no endangerment provisions apply solely within the context of the SDWA itself. It asserts that Part C merely required the EPA to make sure that the states, in implementing their underground injection control programs, did not allow underground injection that would endanger drinking water sources. And so, according to the EPA, Part C imposed no duties which extend beyond its task of establishing minimum requirements for state underground injection control programs. 122 That reading of Part C of the SDWA seems too narrow. Congress enacted Part C because of concern about the indiscriminate underground disposal of hazardous substances, and the resulting possible loss of drinking water resources. The EPA was directed to see that, wherever necessary, the state had regulatory systems in place that would protect against future endangerment of drinking water supplies by underground injections. While the states were to do the regulating, EPA was to determine the adequacy of their programs and was directed to devise and impose regulations of its own if a state did not adopt a proper program. Congress's clear intent was that the states should, inter alia, refrain from adopting regulations which either on their face or as applied would authorize underground injection which endangers drinking water sources. H.R.Rep. No. 1185, 93d Congress, 2d Sess., reprinted in 1974 U.S.Code Cong. & Admin.News 6454, 6481 (emphasis supplied). This blanket policy applies to federal as well as state agencies. 42 U.S.C. Sec. 300h(b)(1)(D). Part C thus establishes a clear federal policy to avoid endangering drinking water supplies through underground injection. Moreover, EPA itself set the drinking water standard which it thought proper to assure public health and safety. 123 It would be anomalous if EPA, as administrator of such a program with a statutory responsibility to assure nonendangerment of drinking water supplies, were free, without examination or explanation, to adopt regulations in other areas of its jurisdiction which authorize underground injections that violate its own standards. Perhaps if it were scientifically impossible to meet the goals of the NWPA except by reducing the standards for sources of drinking water near a repository, this would justify a deviation from the SDWA. Or perhaps there are good reasons reconciling the apparent inconsistency between the two standards. But the administrator nowhere states that compliance with SDWA is impossible or inconsistent with the goals of the NWPA, nor does he offer any explanation of why he deems the lesser standard in the HLW rules to be adequate to protect the public although he does not find it adequate under the SDWA. Moreover, the individual protection requirements apply for 1,000 years, and the Administrator does not explain why drinking water supplies will not be protected at levels established by the SDWA beyond the first 1,000 years. 124 The EPA asserts that absent some type of consistency provision, the requirements of Part C of the SDWA do not apply to rules promulgated under the NWPA. Consistency provisions have been used to expressly require that rules promulgated by the EPA under one statute be consistent with rules under another statute. See, e.g., Uranium Mill Tailings Radiation Control Act, 42 U.S.C. Sec. 2022(a) (1982) (EPA's environmental standards for control of uranium mill tailings must be consistent, to the maximum extent practicable, with requirements under the Resource Conservation and Recovery Act, 42 U.S.C. Secs. 6901-6991 (1982)); Resource Conservation and Recovery Act, 42 U.S.C. Sec. 6905(b) (1982) (EPA must integrate regulations, to maximum extent practicable, with appropriate provisions of the Clean Air Act, the Federal Water Pollution Control Act, the Federal Insecticide, Fungicide and Rodenticide Act, the Safe Drinking Water Act, the Marine Protection, Research and Sanctuaries Act of 1972 and such other Acts of Congress as grant regulatory authority to the Administrator.). 125 Since the NWPA has no such explicit consistency clause, the EPA denies any duty to harmonize the HLW rules with Part C of the SDWA. The Agency argues that neither the NWPA, the SDWA, nor the Administrative Procedure Act, requires every new regulation to dovetail with every other statute and regulation administered by the Agency. But the SDWA is no mere incidental provision. It reflects a national policy and standard relative to the country's water supplies. Safeguarding such resources and their users is likewise implicit in the EPA's duty under the NWPA to promulgate HLW standards for the protection of the general environment from offsite releases from radioactive material in repositories. 42 U.S.C. Sec. 10141(a). EPA's national rule under the SDWA specifying maximum permissible levels of contaminants in public drinking supplies presumably reflects the Agency's best thinking as to what the protection of the public requires. It is puzzling, to say the least, when the same agency now endorses a significantly lower standard--and does so entirely without explanation. Either the SDWA standard is much too stringent or the present standard is inadequate. In the absence of a showing by EPA that, for some reason, the standards of the SDWA are inappropriate to its present task, we think it may not cavalierly ignore those standards. We thus find the current standard arbitrary and capricious. 11 126 The EPA argues that there will be no violation of the SDWA, relying on its statement in the preamble to the HLW rules that they in no way limit the future applicability of the Agency's drinking water standards (40 C.F.R. Part 141)--which protect community water supply systems through institutional controls. 50 Fed.Reg. 38,073, col. 2 (Sept. 19, 1985). The Agency nowhere claims, however, that HLW must be disposed of so that radiation levels will meet SDWA's underground injection rules rather than only the more liberal individual protection standard. Applicability of 40 C.F.R. Part 141 means merely that community water systems must be monitored and treated, as necessary, to ensure that radionuclide concentrations do not exceed the levels allowed under the drinking water standards. See 40 C.F.R. Secs. 141-143 (1985). Thus the Agency's reliance on the future applicability of these rules means, in effect, that the responsibility and burden of cleaning up the excessive radiation releases to drinking water resources will fall on the local water companies. While placing this burden on the local water companies may prevent this contaminated water from being improperly used as drinking water, it will not prevent the future endangerment of drinking water supplies, which is a declared purpose of the Safe Drinking Water Act. 127 We cannot accept the Agency's claim that it may close its eyes to the possible and very likely future violations of the SDWA that will result from these design criteria, while blithely asserting that in the future the SDWA's regulations will still apply so as to protect drinking water. Enforcing the SDWA sometime in the future might well be too late since Congress's intent in enacting Part C of the SDWA was to prevent the endangerment of drinking water sources and thus ensure that there will be sufficient quantities of usable groundwater for future generations. Once those drinking water resources are contaminated, the other regulations under the SDWA may guard against improper use of this water for drinking, but the SDWA will not restore the drinking water sources to their original quality. 128 The simple fact is that disposal of HLW in the manner here contemplated will very likely amount to an underground injection. In announcing criteria which, until far in the future, the planned injection must be presently designed to satisfy, the EPA was irrational to establish, without a word of explanation, different and more relaxed criteria than the EPA's co-existing SDWA standard applicable to all other underground injections. By so doing, DOE and other agencies responsible for site selection and design are left in a quandary as to their possible separate responsibilities under the SDWA, since it is known that underground water will likely be encountered and that future contamination is a serious possibility. To be rational, the HLW regulations either should have been consistent with the SDWA standard--thus requiring repositories to be designed so that future emissions into any sources of drinking water will not result in contamination exceeding SDWA standards--or else should have explained that a different standard was adopted and justify such adoption. As matters now stand, the DOE may be encouraged to expend large sums on site selection, design and construction only to discover itself embroiled in a dispute as to whether the EPA's HLW standards excuse it from securing a state underground injection permit based on the EPA's different, more stringent standards. These are matters the EPA, relying on its expertise, should face and clarify in the HLW regulations; otherwise the HLW regulations will be on a collision course with the SDWA regulations. It is irrational for the EPA, as administrator of both sets of regulations, to ignore the inevitable clash. Rationally, this is the time for the Agency to determine and express its position, since all concerned are entitled to know whether the EPA believes that repositories must meet the SDWA's underground injection control rules as well as the individual protection standards and, if not, the rationale upon which a lesser standard is deemed sufficiently safe. 129 We emphasize that we are not holding that the Agency is necessarily incorrect in promulgating the present standard. We do not possess the necessary expertise to judge whether there are grounds for a lesser standard than that under the SDWA. See South Terminal Corp., 504 F.2d at 665; Duquesne Light Co. v. EPA, 522 F.2d 1186, 1196 (3d Cir.1975). As we are not scientists, we recognize that there could be valid explanations, not occurring to us, which would support a finding that these standards are rational. However, the Agency has never even acknowledged the interrelationship of the two statutes in respect to the Part C underground injection rules, and it has presented no reasoned explanation for the divergence between the level of contamination allowed by the HLW rules and the permissible levels of radiation contamination under the SDWA. Motor Vehicle Manufacturers Association v. State Farm Mutual Insurance Co., 463 U.S. 29, 103 S.Ct. 2856, 77 L.Ed.2d 443 (1983) (agency decision to rescind rule arbitrary and capricious because agency failed to consider relevant issue and failed to give sufficient explanation for decision); Atchison, Topeka & Santa Fe Railway Co. v. Wichita Board of Trade, 412 U.S. 800, 93 S.Ct. 2367, 37 L.Ed.2d 350 (1973) (agency's decision to allow rate change remanded because agency failed to set forth clearly the grounds on which it acted). 130 We hold that, for this reason, the present HLW rules are, on their face, arbitrary and capricious and hence invalid. They must be returned to the Agency for further consideration, which will result in either a new rule or, if the present standard is retained, an explanation of the present apparent inconsistency and irrationality. 131