Full opinion text
Opinion PER CURIAM. PER CURIAM: In these consolidated cases, petitioners challenge both the substance of several rules promulgated by the Environmental Protection Agency pursuant to the Resource Conservation and Recovery Act of 1976 and its compliance with the Administrative Procedure Act’s rulemaking requirements. Consolidated petitioners challenge two rules that categorize substances as hazardous wastes until a contrary showing has been made: the “mixture” rule, which classifies as a hazardous waste any mixture of a “listed” hazardous waste with any other solid waste, and the “derived-from” rule, which so classifies any residue derived from the treatment of hazardous waste. They argue that the EPA failed to provide adequate notice and opportunity for comment when it promulgated the mixture and derived-from rules, and that the rules exceed the EPA’s statutory authority. Three petitioners present separate challenges to other rules included in the same rulemaking. In the first, the American Mining Congress asserts that the EPA exceeded its statutory authority and failed to provide notice and opportunity to comment in defining “treatment” to include processes designed to recover valuable materials from the recycling of solid wastes. Second, the American Petroleum Institute attacks the EPA’s requirement of “leachate monitoring” at land treatment facilities for failure to provide notice and opportunity to comment. (In land treatment, waste is placed upon land or incorporated into the surface soil. Leachate monitoring tests water that has passed through the soil to assure that hazardous wastes or their constituents are not migrating through it.) Finally, the Environmental Defense Fund challenges the EPA’s “permit-shield” provision, a regulation that, with some exceptions, exempts a facility from enforcement proceedings for statutory violations if it is in compliance with its permit conditions. We agree with petitioners that the EPA failed to give sufficient notice and opportunity for comment in promulgating the “mixture” and “derived-from” rules and the leachate monitoring requirement. We therefore remand the rules to the Administrator. We conclude that the regulatory definition of “treatment” does not comport with the statutory definition. The regulation of resource recovery, however, falls within the EPA’s broad authority under Subtitle C to regulate hazardous waste management. Therefore, we deny the American Mining Congress's petition. We also reject its contention that the EPA failed to provide adequate notice of the regulation of resource recovery. As for the permit-shield provision, all parties agree that it cannot trump the citizen’s statutory right to sue. As applied to the Agency, however, the regulation lies well within the limits of the EPA’s enforcement discretion. I. BACKGROUND The EPA promulgated the disputed rules in order to implement the Resource Conservation and Recovery Act (“RCRA”), Pub.L. No. 94-580, 90 Stat. 2795 (1976) (codified as amended at 42 U.S.C. §§ 6901-87 (1988)). RCRA created a “cradle-to-grave” system for tracking wastes from their generation to disposal. The statute consists of two main parts: one governs the management of non-hazardous solid waste; the other, hazardous waste. See American Mining Congress v. EPA, 824 F.2d 1177, 1179 (D.C.Cir.1987) (“AMC I”). As enacted, Subtitle C of RCRA required the EPA to establish a comprehensive national system for safely treating, storing, and disposing of hazardous wastes. It defined “hazardous waste,” in part, as a “solid waste” which may “pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed.” 42 U.S.C. § 6903(5) (1976). It gave the EPA until April 21, 1978 to develop and promulgate criteria for identifying characteristics of hazardous waste and to list particular wastes as hazardous. See id. § 6921(a), (b). It further required the EPA to promulgate regulations “as may be necessary to protect human health and the environment” respecting the practices of generators, transporters, and those who own or operate hazardous waste treatment, storage, or disposal facilities. Id. §§ 6922-6924. RCRA prohibited treatment, storage, or disposal of hazardous waste without a permit and required the EPA to promulgate standards governing permits for facilities performing such functions. Id. § 6925. On February 17, 1977, the EPA published a Notice of Intent to Develop Rulemak-ing, 42 Fed.Reg. 9,803 (1977); and on May 2, 1977, it published an Advance Notice of Proposed Rulemaking, 42 Fed.Reg. 22,332 (1977), which set forth detailed questions on each of the subsections of Subtitle C. In addition, it circulated for comment several drafts of regulations, met with experts and representatives of interested groups, and held public hearings. This process culminated in the publication, on December 18, 1978, of proposed regulations covering most of the statutorily required standards. See 43 Fed.Reg. 58,946-59,022 (1978). This proposal elicited voluminous comment, and the EPA held five large public hearings. The EPA failed to issue final regulations by the April 1978 statutory deadline; several parties sued the Agency to compel it to do so. Although the district court initially ordered the EPA to promulgate the regulations by December 31, 1979, the complexity of the task led the court to modify the order to require, instead, that the EPA use its best efforts to issue them by April 1980. The EPA published its “[revisions to final rule and interim final rule” on May 19, 1980. 45 Fed.Reg. 33,066 (1980). It noted that time pressures had had an effect on the new regulations: Because of limited information, the Agency was unable to avoid underregulation and overregulation. It complained that the demands of developing a national, comprehensive system of hazardous-waste management made precise tailoring to individual cases impossible. See id. 33,088. More than fifty petitions were brought to challenge these final rules. In 1982, we deferred briefing on these challenges to allow the parties to pursue settlement discussions and ordered the EPA to file monthly status reports. We did not stay the rules, however, which have remained in effect. Most of the issues have been resolved by settlement, by subsequent statutory or regulatory revision, or by the failure of petitioners to pursue them. The issues presented here are those that the EPA identified in January 1987 as unlikely to be settled, and that were subject to the briefing schedule established by this court on June 12, 1989. Consolidated petitioners assert that the regulations proposed on December 18,1978 did not foreshadow the inclusion of the mixture and derived-from rules in the final rule’s definition of “hazardous waste.” See 45 Fed.Reg. 33,119-20 (40 C.F.R, § 261.3). Thus, they assert, they were deprived of adequate notice and opportunity for comment. They also claim that the EPA exceeded its statutory authority by including the two rules in the final definition of hazardous waste. The American Mining Congress challenges the statutory authority for the definition of “treatment” found in the final rules. See id. 33,076 (40 C.F.R. § 260.10(73)). The American Petroleum Institute attacks the leachate monitoring requirements for land treatment facilities included in the final rules, see id. 33,248 (40 C.F.R. § 265.278(b)(2)), because the proposed regulations did not address the possibility of imposing such a requirement, thus depriving them of adequate notice and opportunity for comment. The Environmental Defense Fund asserts that the issuance of the permit-shield rule, which first appeared in the May 1980 rule-making, see id. 33,428 (40 C.F.R. § 122.-13(a)), was arbitrary and capricious and that the rule is outside the scope of the statute. We consider each of these challenges in turn. II. Discussion A. Principles Governing Judicial Review The Administrative Procedure Act (“APA”) governs judicial review of final regulations promulgated under RCRA. 42 U.S.C. § 6976 (1976) (citing 5 U.S.C. §§ 701-706). In issuing regulations, the EPA must observe the notice-and-comment procedures of the APA, 5 U.S.C. § 553(b) (1988), and the public-participation directive of RCRA, 42 U.S.C. § 6974(b) (1976). The relationship between the proposed regulation and the final rule determines the adequacy of notice. A difference between the two will not invalidate the notice so long as the final rule is a “logical outgrowth” of the one proposed. If the deviation from the proposal is too sharp, the affected parties will not have had adequate notice and opportunity for comment. See American Fed’n of Labor v. Donovan, 757 F,2d 330, 338-39 (D.C.Cir.1985). RCRA defines the scope of the EPA’s regulatory discretion: In formulating rules, the clearly expressed intent of Congress binds agencies as it binds courts. Where congressional intent is ambiguous, however, an agency’s interpretation of a statute entrusted to its administration is entitled to deference, so long as it is reasonable. Chevron U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-43, 104 S.Ct. 2778, 2781-82, 81 L.Ed.2d 694 (1984). B. The Mixture and Derived-From Rules The mixture and derived-from rules are to be found in the definition of “hazardous waste” that appears in the final rules. That definition includes as hazardous all wastes resulting from mixing hazardous and other wastes and from treating, storing, or disposing of hazardous wastes, until such time as the wastes are proven nonhazardous. Petitioners protest that these provisions had no counterpart in, and were not a logical outgrowth of, the proposed regulations; thus, the promulgation of the rules violated the notice-and-comment requirements of RCRA and the APA. We agree. 1. Statutory Background To become subject to RCRA’s comprehensive regulatory system, a material must be a hazardous waste, which RCRA defines, in part, as: a solid waste, or combination of solid wastes, which because of its quantity, concentration, or physical, chemical, or infectious characteristics may— ****** (B) pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed. 42 U.S.C. § 6903(5) (1976). To determine what materials fall within that definition, the EPA must promulgate criteria for the identification and listing of hazardous wastes. The statute provides the EPA with specific instructions for identifying and listing hazardous waste: (a) Criteria for identification or listing Not later than eighteen months after October 21, 1976, the Administrator shall, after notice and opportunity for public hearing, and after consultation with appropriate Federal and State agencies, develop and promulgate criteria for identifying the characteristics of hazardous waste, and for listing hazardous waste, which should be subject to the provisions of this subchapter, taking into account toxicity, persistence, and degrad-ability in nature, potential for accumulation in tissue, and other related factors such as flammability, corrosiveness, and other hazardoüs characteristics. Such criteria shall be revised from time to time as may be appropriate. (b) Identification and listing Not later than eighteen months after October 21, 1976, and after notice and opportunity for public hearing, the Administrator shall promulgate regulations identifying the characteristics of hazardous waste, and listing particular hazardous wastes (within the meaning of section 6903(5) of this title), which shall be subject to the provisions of this subchap-ter. Such regulations shall be based on the criteria promulgated under subsection (a) of this section and shall be revised from time to time thereafter as may be appropriate. Id. § 6921(a), (b). 2. The Proposed Regulations In its proposed regulations, the EPA adopted the following definition of “hazardous waste”: “Hazardous waste” has the meaning given in [RCRA, 42 U.S.C. § 6903(5)] as further defined and identified in this Subpart. 43 Fed.Reg. 58,955 (proposed 40 C.F.R. § 250.11(b)(3)) (emphasis added). The regulations then set forth the following scheme for identifying and listing hazardous wastes: (a) Criteria for identifying the characteristics of hazardous waste. A characteristic of hazardous waste will be established under § 250.13 where, based on information from damage incidents or scientific and technical information, the Administrator determines that: (1) The characteristic can be defined in terms of specific physical, chemical, toxic, infectious, or other properties of a solid waste that will cause the waste to be a hazardous waste pursuant to the definition in [42 U.S.C. § 6903(5) ], and (2) The properties defining the characteristic are measurable by standardized and available testing protocols applicable to waste. (b) Criteria for listing hazardous waste. A solid waste, or source or class of solid waste, will be listed as a hazardous waste in § 250.14 if the Administrator determines that the solid waste: (1) Possesses any of the characteristics defined in § 250.13, and/or (2) Meets the definition of hazardous waste found in [42 U.S.C. § 6903(4)]. 43 Fed.Reg. 58,955 (proposed 40 C.F.R. § 250.12(a), (b)). Although the EPA initially identified nine possible characteristics as potentially hazardous, it decided to rely on only four of them — ignitability, corrosivity, reactivity, and toxicity — in its proposed section 250.13, because only these could be tested reliably and inexpensively. Id. 58,950, 58,-955-57. Because solid wastes that present a hazard but do not display one of these four characteristics remained subject to RCRA, the EPA proposed to list such wastes specifically, id. 58,957-58 (proposed 40 C.F.R. § 250.14), and to treat any waste once listed as hazardous until a person managing the waste filed a delisting petition and demonstrated to the EPA that the waste did not pose a hazard. Id. 58,959-60 (proposed 40 C.F.R. § 250.15). 3. The Final Rules The final rules defined a hazardous waste more broadly than did the proposed regulations. Under the final rules, a hazardous waste is a solid waste that is not specifically excluded from regulation and meets any one of the following criteria: (i) It is listed in Subpart D and has not been excluded from the lists in Subpart D under §§ 260.20 and 260.22 of this Chapter. (ii) It is a mixture of solid waste and one or more hazardous wastes listed in Sub-part D and has not been excluded from this paragraph under §§ 260.20 and 260.22 of this Chapter. (iii) It exhibits any of the characteristics of hazardous waste identified in Subpart C. 45 Fed.Reg. 33,119 (40 C.F.R. § 261.-3(a)(2)). In addition, a solid waste generated from the treatment, storage, or disposal of a hazardous waste is considered a hazardous waste. Id. 33,120 (40 C.F.R. § 261.-3(c)(2)). In establishing criteria for identifying and listing hazardous wastes in its final rules, the EPA relied heavily on the dangers that such wastes pose. See 45 Fed. Reg. 33,121 (40 C.F.R. §§ 261.10-.il). Thus the EPA compiled a list of toxic constituents as a starting point and required that a waste be listed as hazardous if it (1) exhibits one of the four characteristics of hazardous waste identified in Subpart C of the regulations (“hazardous characteristics”), (2) meets certain toxicity criteria, or (3) contains any of the toxic constituents listed in Appendix VIII unless, after considering any of the following factors, the Administrator concludes that the waste is not capable of posing a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported or disposed of, or otherwise managed. Id. 33,121 (40 C.F.R. § 261.11(a)(lH3)). The final rules, moreover, provide for de-listing by formal notice and comment rule-making rather than by the more informal procedure using defined thresholds that was initially proposed by the EPA. Id. 33,076-77 (40 C.F.R. §§ 260.20, 260.22); 43 Fed.Reg. 58,959-60 (proposed 40 C.F.R. § 250.15). A number of interested parties had challenged the listing of classes of wastes in the proposed regulations as an unwarranted expansion of the statutory phrase “particular wastes,” which, they asserted, required the listing of specific wastes only. See 45 Fed.Reg. 33,114. The EPA nevertheless retained the proposed scheme in its final rules, stating that its use of classes was justified by the complexity of the factors bearing on hazard and the impossibility of defining a numerical threshold level for hazardous characteristics. See id. 33,105. 4. The Mixture Rule The mixture rule requires that a waste be treated as hazardous if [i]t is a mixture of solid waste and one or more hazardous wastes listed in Subpart D and has not been excluded from this paragraph under §§ 260.20 and 260.22 of this Chapter. 45 Fed.Reg. 33,119 (40 C.F.R. § 261.-3(a)(2)(ii)). Once classified as hazardous, then, a mixture must be so treated until delisted. The EPA acknowledged at the outset that the mixture rule was “a new provision,” and that it had no “direct counterpart in the proposed regulations." 45 Fed. Reg. 33,095. Nevertheless, it added the rule for purposes of clarification and in response to questions raised during the comment period concerning waste mixtures and when hazardous wastes become subject to and cease to be subject to the Subtitle C hazardous waste management system. Id. Although admitting that it had failed to say so in the proposed regulations, the EPA stated that it had “intended” to treat waste mixtures containing Subpart D wastes as hazardous. It then presented the mixture rule as necessary to close “a major loophole in the Subtitle C management system.” Id. 33,095. Otherwise,, generators of hazardous waste “could evade [those] requirements simply by commingling [Subpart D] wastes with nonhazardous solid waste” to create a waste that did not demonstrate any of the four testable characteristics but that posed a hazard for another reason. Id. The Agency explained that although the mixture rule might include waste with concentrations of Subpart D wastes too low to pose a hazard, the delisting process and the possibility of segregating waste to avoid the problem mitigated the burden of the rule. Finally, the EPA invoked the practical difficulties of its task to justify the rule’s adoption: Because the potential combinations of listed wastes and other wastes are infinite, we have been unable to devise any workable, broadly applicable formula which would distinguish between those waste mixtures which are and are not hazardous. Id. While the EPA admits that the mixture rule lacks a clear antecedent in the proposed regulations, it nonetheless argues that the rule merely clarifies the intent behind the proposal that listed wastes remain hazardous until delisted: As industry could not have reasonably assumed that a generator could bring a listed waste outside the generic listing description simply by mixing it with a nonhazardous waste, the rule cannot be seen as a “bolt from the blue.” Cf. WJG Telephone Co., Inc. v. FCC, 675 F.2d 386, 388-90 (D.C.Cir.1982). 5. The Derived-From Rule The derived-from rule provides that [a]ny solid waste generated from the treatment, storage or disposal of a hazardous waste, including any sludge, spill residue, ash, emission control dust or leachate (but not including precipitation run-off), is a hazardous waste. 45 Fed.Reg. 33,120 (40 C.F.R. § 261.3(c)(2)). Subpart D wastes continue to be regulated as hazardous until delisted; a solid waste derived from Subpart C wastes may emerge from regulation if it does not itself display a hazardous characteristic. See id. 33,120 (40 C.F.R. § 261.3(d)). The EPA’s justifications for the derived-from rule resemble those for the mixture rule. Arguing that the products of treatment, storage, or disposal of listed hazardous wastes usually continue to pose hazards, the EPA defends the rule as “the best . regulatory approach we can devise,” given the fact that “[w]e are not now in a position to prescribe waste-specific treatment standards which would identify those processes which do and do not render wastes or treatment residues nonhazardous.” 45 F'ed.Reg. 33,096. The EPA acknowledged, however, that the rule was a new provision, “added both in response to comment and as a logical outgrowth of [§ 261.3(b)].” Id. 6. Adequacy of Notice Although the EPA acknowledges that •neither of the two rules was to be found among the proposed regulations, it nevertheless argues that they were foreseeable — and, therefore, the notice adequate— because certain of the comments received in response to the rulemaking appeared to anticipate both the mixture and the derived-from rules. We are unimpressed by the scanty evidence marshaled in support of this position. The only comment actually cited by the EPA was made by the Manufacturing Chemists Association, which stated that under the proposed regulations, “a listed waste is a hazardous waste regardless of quantity or concentration,” and that “[i]t is not reasonable to classify all waste streams which contain any concentration of one of the specific wastes as hazardous.” EPA, Comments of Manufacturing Chemists Ass’n, D-1384 at 74, reprinted in Joint Appendix (“J.A.”) at 114 (emphasis in the original). This comment, we note, addresses the initial classification of a waste as hazardous rather than the problem of how to deal with residues resulting from the treatment of wastes, or with their subsequent mixture with other, nonhazardous materials. The EPA also draws attention to a response it made before the close of the comment period to a question posed by the American Mining Congress in which the Agency indicated that the delisting procedure would permit generators to remove wastes from the RCRA system. This, apparently, is supposed to have alerted interested parties that delisting would be the only means of exit from regulation. But examination of the precise words that the EPA used reveals a different message. The EPA stated that “[de]listing provides a means on a case by case basis for [the generator of a given waste] to demonstrate that that waste does not belong in the system at all.” EPA, Transcript of Public Hearing (Mar. 7-9, 1979), D-2703 at 29, reprinted in J.A. at 163. This response concerned the exclusion from regulation of wastes included by initial regulatory error, not the deregulation of wastes that have ceased to be hazardous. The EPA’s remaining evidence of implied notice is equally unimpressive. It consists of generalized references to comments urging that wastes be evaluated only according to the four easily testable characteristics, EPA, 1980 Background Document, D-2377 at 51, reprinted in J.A. at 575, and requests that the regulations specifically address the disposition of incinerator ash. Id., D-2372 at 46, reprinted in J.A. at 549. An agency, of course, may promulgate final rules that differ from the proposed regulations. To avoid “the absurdity that ... the agency can learn from the comments on its proposals only at the peril of starting a new procedural round of commentary,” International Harvester Co. v. Ruckelshaus, 478 F.2d 615, 632 n. 51 (D.C.Cir.1973), we have held that final rules need only be a “logical outgrowth” of the proposed regulations. Small Refiner Lead Phase-Down Task Force v. EPA, 705 F.2d 506, 546-47 (D.C.Cir.1983) (canvassing precedent). But an unexpressed intention cannot convert a final rule into a “logical outgrowth” that the public should have anticipated. Interested parties cannot be expected to divine the EPA’s unspoken thoughts. See Small Refiner, 705 F.2d at 548-49. The reasons given by the EPA in support of its contention that interested parties should have anticipated the new rules are simply too insubstantial to justify a finding of implicit notice. While it is true that such parties might have anticipated the potential for avoiding regulation by simply mixing hazardous and nonhazardous wastes, it was the business of the EPA, and not the public, to foresee that possibility and to address it in its proposed regulations. Moreover, while a comment may evidence a recognition of a problem, it can tell us nothing of how, or even whether, the agency will choose to address it. The comments the EPA cites strike us as sparse and ambiguous at best. Some address similar concerns, but none squarely anticipates the rules. Even if the mixture and derived-from rules had been widely anticipated, comments by members of the public would not in themselves constitute adequate notice. Under the standards of the APA, “notice necessarily must come — if at all— from the Agency.” Small Refiner, 705 F.2d at 549; see also American Fed’n of Labor v. Donovan, 757 F.2d at 340 (holding that the court cannot “properly attribute notice to [interested parties] on the basis of an assumption that they would have monitored the submission of comments.”). Although we have held that comments raising a foreseeable possibility of agency action can be a factor in providing^ notice, NRDC v. Thomas, 838 F.2d 1224, 1243 (D.C.Cir.), cert. denied sub nom. Alabama Power Co. v. Thomas, 488 U.S. 888, 109 S.Ct. 219, 102 L.Ed.2d 210 (1988), this is not such a case. While, in Thomas, the New York State Attorney General’s Office suggested a regulatory approach similar to that finally adopted by the EPA, the Agency itself gave warning of its approach two weeks before final promulgation, and the industry petitioners had “at least a limited opportunity to focus a direct attack.” Id. In fact, they “managed to file objections 7-10 days before the final regulations were signed.” Id. We nevertheless acknowledged that the case “stretche[d] the concept of ‘logical outgrowth’ to its limits.” Id. In contrast, here, the ambiguous comments and weak signals from the agency gave petitioners no such opportunity to anticipate and criticize the rules or to offer alternatives. Under these circumstances, the mixture and derived-from rules exceed the limits of a “logical outgrowth.” The EPA’s argument also fails to take into account a marked shift in emphasis between the proposed regulations and the final rules. Under the EPA’s initial regulatory strategy, the EPA planned to identify and quantitatively define all of the characteristics of hazardous waste.... Generators would be required to assess their wastes in accordance with these characteristics and EPA would list hazardous wastes where it had data indicating the wastes exhibited one of the identified characteristics. 45 Fed.Reg. 33,106. As a consequence, listing was to “play [the] largely supplementary function” of increasing the “certainty” of the process. Id. Listing was also to have relieved generators of listed wastes of the burden of testing for characteristics “unless they wish to demonstrate that they are not subject” to Subtitle C regulation. 43 Fed.Reg. 58,951. Thus, the proposed regulations imposed, as a generator’s principal responsibility, the duty to test wastes for hazardous characteristics and suggested that if the required tests failed to reveal a hazard, the waste would not need to be managed as hazardous. The final rules, however, place a heavy emphasis on listing. As a consequence, the final criteria for listing are “considerably expanded and more specific” than those proposed. 45 Fed.Keg. 33,106. The EPA justified this “change in emphasis in [its] regulatory strategy,” id. 33,107, on the basis that it was “not fully confident that it can suitably define and construct testing protocols for [several] characteristics.” Id. Whatever the basis for this shift in strategy, it erodes the foundation of the EPA’s argument that the mixture rule was implicit in the proposed regulations. A system that would rely primarily on lists of wastes and waste-producing processes might imply inclusion of a waste until it is formally removed from the list. The proposed regulations, however, did not suggest such a system. Rather, their emphasis on characteristics suggested that if a waste did not exhibit the nine characteristics originally proposed, it need not be regulated as hazardous. We conclude, therefore, that the mixture rule was neither implicit in nor a “logical outgrowth” of the proposed regulations. Similarly, while the derived-from rule may well have been the best regulatory approach the EPA could devise, 45 Fed. Reg. 33,096, it was not a logical outgrowth of the proposed regulations. The derived-from rule is not implicit in a system based upon testing wastes for specified hazardous characteristics — the system presented in the proposed regulations. To the contrary, the derived-from rule becomes coun-terintuitive as applied to processes designed to render wastes nonhazardous. Rather than presuming that these processes will achieve their goals, the derived-from rule assumes their failure. Our opinion in Chemical Waste Management, Inc. v. EPA, 869 F.2d 1526 (D.C.Cir.1989), does not suggest a contrary result. There, we characterized the regulation providing for the retroactive application of the derived-from rule as “an entirely reasonable (if not inevitable) construction of the regulation,” and found that the EPA provided adequate notice and opportunity for comment on that regulation. Id. 1534-35. That holding, however, had no bearing on the validity of the derived-from rule itself, as that question was not before the court. See id. 1530 n. 4. The EPA maintains, finally, that it had considered and rejected the points raised by petitioners, and argues that they cannot show prejudice from its failure to provide notice and opportunity to comment. While petitioners must show that they would have submitted new arguments to invalidate rules in the case of certain procedural defaults, such as an agency’s failure to provide access to supplemental studies, see Air Transport Ass’n of America v. CAB, 732 F.2d 219, 224 n. 11 (D.C.Cir.1984), petitioners need not do so here, where the agency has entirely failed to comply with notice-and-comment requirements, and the agency has offered no persuasive evidence that possible objections to its final rules have been given sufficient consideration. See McLouth Steel Prods. Corp. v. Thomas, 838 F.2d 1317, 1324 (D.C.Cir.1988) (“we cannot say with certainty whether petitioner’s comments would have had some effect if they had been considered when the issue was open”). Because the EPA has not provided adequate notice and opportunity for comment, we conclude that the mixture and derived-from rules must be set aside and remanded to the EPA. In light of the dangers that may be posed by a discontinuity in the regulation of hazardous wastes, however, the agency may wish to consider reenacting the rules, in whole or part, on an interim basis under the “good cause” exemption of 5 U.S.C. § 553(b)(3)(B) pending full notice and opportunity for comment. See, e.g., Mid-Tex Elec. Co-op., Inc. v. FERC, 822 F.2d 1123, 1131-34 (D.C.Cir.1987). As we vacate them on procedural grounds, we do not reach petitioners’ argument that the mixture and derived-from rules unlawfully expand the EPA’s jurisdiction under Subtitle C of RCRA. C. Treatment The American Mining Congress (“AMC”) challenges the EPA’s regulatory definition of the term “treatment.” In its proposed regulations, the EPA adopted RCRA’s definition of “treatment” as any method, technique, or process, including neutralization, designed to change the physical, chemical, or biological character or composition of any hazardous waste so as to neutralize such waste or so as to render such waste nonhazardous, safer for transport, amendable [sic] for recovery, amenable for storage, or reduced in volume. Such term includes any activity or processing designed to change the physical form or chemical composition of hazardous waste so as to render it nonhazardous. 42 U.S.C. § 6903(34) (1976); see 43 Fed. Reg. 58,955, 58,976, and 58,996 (proposed 40 C.F.R. §§ 250.11(a)(ll), 250.21(a)(12), and 250.41(a)(15)). In its final rules, however, the EPA expanded the definition to include any method, technique, or process, including neutralization, designed to change the physical, chemical, or biological character or composition of any hazardous waste so as to neutralize such waste, or so as to recover energy or material resources from the waste, or so as to render such waste non-hazardous, or less hazardous; safer to transport, store, or dispose of; or amenable for recovery, amenable for storage, or reduced in volume. 45 Fed.Reg. 33,076 (40 C.F.R. § 260.10(73)) (emphasis added). The AMC contends that in promulgating the expanded definition, the EPA exceeded its statutory authority by including resource recovery and failed to afford interested parties adequate notice and opportunity to comment. The EPA grounds its authority for regulating resource recovery in the statutory definition of treatment and, more broadly, in its Subtitle C authority to manage hazardous wastes from their generation until after their disposal. Because we are persuaded that Subtitle C provides broad authority for regulating the management of hazardous waste and does not prohibit the regulation of resource recovery from hazardous wastes, we deny the AMC’s petition. We also reject its argument that the regulations were promulgated without sufficient notice and opportunity for comment. 1. Chevron In reviewing the EPA’s interpretation of the governing statute, we first determine, by applying traditional rules of statutory interpretation, “whether Congress has directly spoken to the precise question at issue.” Chevron, 467 U.S. at 842, 104 S.Ct. at 2781. If so, “that is the end of the matter; for the court, as well as the agency, must give effect to the unambiguously expressed intent of Congress.” Id. at 842-43, 104 S.Ct. at 2781-82. “[I]f the statute is silent or ambiguous with respect to the specific issue,” however, we must sustain the agency’s construction of the statute so long as it is permissible. Id. at 843, 104 S.Ct. at 2781. Our initial task, then, is to decide whether Congress excluded resource recovery from the statutory scheme of regulation of hazardous wastes. We conclude that it did not. 2. Analysis The AMC launches a powerful attack on EPA’s reliance on the statutory definition of treatment as the source of its authority to regulate resource recovery from hazardous wastes. We agree that the statutory language will not bear the weight put on it by the EPA. The statutory definition states what “treatment” means, as opposed to what it includes. Thus, while the statute lists the types of activities that can constitute treatment, a “method, technique, or process” is treatment only if it is designed to change the character or composition of wastes to achieve one of the definition’s enumerated purposes. These purposes include processes designed to render waste safer and more amenable for recovery, for example, but does not mention the regulation of resource recovery. Moreover, while the definition includes processes designed to “render ... waste ... safer for transport,” it excludes transporting the waste; and while it includes processes designed to “render ... waste ... amenable for storage,” it excludes storing the waste. Thus, we conclude that the definition does not provide explicit authority for the regulation of resource recovery from hazardous wastes. This, however, does not end our inquiry. The EPA also argues that its authority to regulate resource recovery is inherent in its statutory mandate to manage hazardous wastes. See 45 Fed.Reg. 33,091-92. Subtitle C creates a “cradle-to-grave” regulatory system in which the EPA is charged with the responsibility for managing hazardous waste. See 42 U.S.C. §§ 6921-31 (1976); see also American Petroleum Inst. v. EPA, 906 F.2d 729, 732-33 (D.C.Cir.1990) (“API”). RCRA broadly defines “hazardous waste management” as “the systematic control of the collection, source separation, storage, transportation, processing, treatment, recovery, and disposal of hazardous wastes.” 42 U.S.C. § 6903(7). In interpreting the Act, we have made clear that the linchpins of the Subtitle C system are the definitions of “hazardous waste” and “solid waste.” Only materials that meet both definitions will come within the “cradle-to-grave” regulatory scheme. AMC I, 824 F.2d at 1179; API, 906 F.2d at 733 (“Once a waste is listed or identified as hazardous, its subsequent management is regulated.”). Under these definitions, a substance is not classified as waste, whether hazardous or not, until it has been discarded. See 42 U.S.C. § 6903(27); AMC I, 824 F.2d at 1190; compare American Mining Congress v. EPA, 907 F.2d 1179, 1185-87 (D.C.Cir.1990) (“AMC IF) (although EPA may not classify as “discarded” materials that are “destined for beneficial reuse or recycling in a continuous process by the generating industry itself,” it may treat sludges held in wastewater treatment surface impoundments as “discarded” despite prospect of later resource recovery). At that point, if it is hazardous, it falls within the jurisdiction of the EPA, which is then responsible for its management until such time as it ceases to pose a hazard to the public. As we have noted elsewhere, the creation of a “framework for a national system to insure the safe management of hazardous waste” was “Congress' overriding concern in enacting RCRA.” AMC I, 824 F.2d at 1179 (internal quotation marks omitted). Thus, Congress specifically found that hazardous waste presents, in addition to the problems associated with non-hazardous solid waste, special dangers to health and requires a greater degree of regulation than does non-hazardous solid waste. 42 U.S.C. § 6901(b)(5) (1976). To fulfill this mandate, Congress granted the EPA, in Subtitle C, the specific authority to: (1) promulgate criteria for identifying characteristics of hazardous waste and for listing such wastes, 42 U.S.C. § 6921; (2) set out standards applicable to generators of hazardous waste, id. § 6922; (3) create standards applicable to transporters of hazardous wastes, id. § 6923; and (4) set out standards and design permit requirements for facilities that treat, store, or dispose of hazardous waste, id. §§ 6924-25. The statute established a separate regime outside of Subtitle C for the recovery of resources from solid wastes. Subtitle D of RCRA, 42 U.S.C. §§ 6941-49, seeks “to assist in developing and encouraging methods for the disposal of solid waste which are environmentally sound and which maximize the utilization of valuable resources and to encourage resource conservation.” Id. § 6941 (1976). Resource recovery is treated as a means to control and manage solid wastes, but not hazardous wastes. The fostering of resource recovery falls in the first instance to the States for inclusion in solid waste management plans. See, e.g., id. §§ 6941, 6942(c)(10), 6943(6). Although RCRA addresses resource recovery from nonhazardous solid wastes, it is silent as to how the extraction of any recoverable value is to be handled once a material falls within the EPA’s exclusive jurisdiction as hazardous waste. Yet, one purpose of the statute is to conserve useful resources, see id. §§ 6902(1) and (7), and such recovery may be incident to the management of hazardous wastes. Thus, we are faced with the question of whether the absence of the words “resource recovery” from the statutory definition of “treatment,” and the absence of any specific discussion of resource recovery in Subtitle C, requires the EPA to recede from its clear regulatory role in the management of hazardous wastes during periods when useable resources are being salvaged from them. The EPA believes the answer is self-evident: Once hazardous solids are discarded, it becomes the EPA’s responsibility, through regulation, to manage them in the public interest. The Agency concluded that RCRA does not permit such an exception from the comprehensive management system created by Subtitle C. The EPA insists that to assert otherwise, to assert that hazardous materials may be removed from this “cradle-to-grave” regulatory system whenever resources are recovered from hazardous wastes, would create a paradoxical system. Such wastes would be subject to manifesting requirements and transportation restrictions, and could be subject to permitting requirements if sent to a treatment, disposal, or storage facility, but would not be subject to any regulatory safeguards if sent to a resource recovery facility. Yet, resource recovery and recycling activities pose the same kinds of dangers that treatment and storage do. See 45 Fed.Reg. 33,091; 48 Fed.Reg. 14,505-07 (1983) (examples of accidents involving recycling of hazardous wastes). As the EPA noted in promulgating the final rules, such a system could significantly undermine the entire regulatory structure. Excluding resource recovery from hazardous wastes from Subtitle C jurisdiction would make the regulatory program largely unworkable and create a major regulatory loophole not intended by the Act. Without a manifest system (or its functional equivalent) there would be no way of assuring that wastes which were intended to be used, re-used, recycled or reclaimed were in fact delivered to their intended destination. Whether a waste was subject to Subtitle C requirements would be based primarily on the intent of the person handling it. 45 Fed.Reg. 33,091. Under Chevron, if we determine that Congress has not spoken to the precise question at issue, we must assume that Congress implicitly delegated to the agency the power to make policy choices that represent ] a reasonable accommodation of conflicting policies that were committed to the agency’s care by the statute. Ohio v. Dep’t of the Interior, 880 F.2d 432, 441 (D.C.Cir.1989) (quoting Chevron, 467 U.S. at 844-45, 104 S.Ct. at 2782-83 (internal quotation marks omitted)). Although Subtitle C is silent on the question of resource recovery from hazardous waste, its structure and its broad grant of authority to the EPA to manage the problem of hazardous waste make it unclear, at the very least, whether Congress intended to exempt resource recovery from what is otherwise a comprehensive mandate to regulate hazardous wastes. Therefore, we cannot say that Congress has spoken to the precise issue before us. Under such circumstances, Chevron requires us to defer to the EPA’s construction of its authority under Subtitle C so long as it “is reasonable and consistent with the statutory purpose.” Ohio v. Dep’t of the Interior, 880 F.2d at 441. As Subtitle C, read as a whole, provides broad authority to the EPA to fashion rules to govern the management of hazardous wastes, it would seem entirely reasonable for the EPA to conclude that it has the authority to regulate the extraction of resources from the wastes committed to its care. Nevertheless, the AMC relies specifically on our decision in AMC I to argue that the EPA does not have authority to regulate resource recovery from hazardous wastes because the recovery occurs within the industrial process. In AMC I, however, we held that secondary materials that are “destined for immediate reuse in another phase of the industry’s.ongoing process ... have not yet become part of the waste disposal problem” and therefore are not solid wastes. AMC I, 824 F.2d at 1185-86; compare AMC II, 907 F.2d at 1185-87. AMC I does not affect in any way the EPA’s ability to regulate hazardous materials after they have been discarded. See 42 U.S.C. § 6903(27) (defining “solid waste” as “discarded material ... resulting from industrial [and other] activities”). Indeed, our subsequent holding in API strongly suggests that hazardous wastes sent to reclamation facilities fall within the scope of Subtitle C regulation. In API, we rejected the EPA’s view that the definition of solid waste, and our decision in AMC I, barred the regulation of K061 slag sent to a reclamation facility. The EPA believed that because the slag was sent to a reclamation facility, it could not be considered “discarded” and thus was not a solid waste. We rejected that reading of AMC I as too broad and remanded for reconsideration. We noted that “it appears unlikely that EPA can simply readopt the conclusion that its authority to regulate K061 ends at the door of the reclamation facility. To reach such a conclusion, EPA would have to reconcile this position with the RCRA’s acknowledged objective to establish[ ] a cradle-to-grave regulatory structure for the safe handling of hazardous wastes.” API, 906 F.2d at 741 (quoting United Technologies Corp. v. EPA, 821 F.2d 714, 716 (D.C.Cir.1987) (internal quotation marks omitted)). We believe the EPA has correctly resolved part of the API court’s challenge: If a hazardous material has been discarded, it becomes subject to Subtitle C regulation even if it is sent to a resource recovery facility. Given the structure of Subtitle C and the power delegated to the EPA, we find the Agency’s regulation of resource recovery from hazardous wastes to be permissible under RCRA. Further, we believe the EPA acted reasonably in incorporating resource recovery within the regulatory definition of treatment. See 45 Fed.Reg. 33,-091-92. See also API, 906 F.2d at 740-41 n. 15 (reference to use of metal reclamation facilities “to treat discarded hazardous wastes”). Thus, we deny the AMC’s petition challenging the EPA’s authority to regulate resource recovery. 3. Notice and Comment The AMC also contends that the EPA included resource recovery within the purview of Subtitle C without providing adequate notice and opportunity for comment. We disagree. The EPA’s initial Notice of Intent to Develop Rulemaking, 42 Fed.Reg. 9,803, stated that the rulemaking would address “the recovery and reuse of ... discarded materials as well as ... the careful management of all hazardous wastes.” The preamble to the proposed regulations mirrored this statement of purpose, noting that the structure to be created would “establish a comprehensive system designed to safely dispose of, treat, store or reuse hazardous waste.” 43 Fed. Reg. 58,947. More specifically, the phrase “other discarded material” in the statutory definition of solid waste was defined in the EPA’s proposed regulations, in part, as any material which: (1) Is not re-used (that is, is abandoned or committed to final disposition) or, (2) Is re-used (including materials treated prior to re-use) (i) If such re-use constitutes disposal (as defined in the Act), ... 43 Fed.Reg. 58,954 (proposed C.F.R. § 250.-10(b)). In analyzing this proposed definition, the EPA explained that used materials sent to reclamation facilities would be subject to Subtitle C only if they were hazardous wastes. Id. 58,950. Further, the EPA noted that “[o]ther materials and their uses will be included by amendment to this list upon a finding by the EPA that it is necessary to control such uses.” Id. 58,954. Background documents circulated by the EPA prior to the promulgation of the final rules also addressed the regulation of resource recovery and re-use of hazardous waste. In one, the Agency compared “treatment” to “disposal”: While safe techniques for land disposal (e.g. landfilling) can protect public health and the environment, land disposal waste management options generally do not provide opportunities for resource conservation or recovery_ In contract [sic], waste treatment options, such as incineration and chemical/physical/biological treatment, can destroy hazardous waste (or render it non-hazardous) once and for all, while providing the potential for energy and/or material recovery at the same time.... Also, the public is more likely to accept a treatment/recovery facility than a land disposal facility. EPA, Background Document D-623 at 2 (1978), reprinted in J.A. at 101. This reflects the Agency’s view that resource, recovery is a form of treatment. The EPA argues that even if the preambles, the explanation of the solid waste definition, and the background document did not make clear its intention to regulate resource recovery, such regulation was a logical outgrowth of these discussions. Certainly, interested parties who filed comments recognized that the EPA viewed resource recovery as within its Subtitle C jurisdiction. The comments detailed in the final rules show a recognition that the EPA contemplated regulation of resource recovery. See 45 Fed.Reg. 33,091-92. Thus, unlike its argument regarding the mixture and derived-from rules, the EPA does not locate notice in these comments but adduces them to show the adequacy of notice. The EPA’s proposed regulations, explanation, and background documents reflect that it considered resource recovery to be within the scope of Subtitle C. These materials also suggest, although they do not conclusively state, that the EPA considered resource recovery as a form of treatment. The specific inclusion of resource recovery within the “cradle-to-grave” system appears to be a logical outgrowth of these statements. Small Refiner, 705 F.2d at 546-47. We therefore reject the AMC’s petition to remand these regulations for notice and comment. D. Leachate Monitoring The American Petroleum Institute (“API”) challenges the EPA’s interim final rule requiring that land treatment facilities perform leachate monitoring. See 45 Fed. Reg. 33,248 (40 C.F.R. § 265.278(b)(2)). It contends that the EPA promulgated the rule without affording interested parties the notice and opportunity to comment that the APA requires. See 5 U.S.C. § 553 (1988). We agree. RCRA requires the EPA to issue performance standards for owners and operators of hazardous waste treatment, storage, and disposal facilities. See 42 U.S.C. § 6924 (1976). Pursuant to that obligation, the EPA proposed monitoring requirements for three types of waste facilities: landfills (“disposal facilities] ... where hazardous waste is placed in or on land,” 45 Fed.Reg. 33,075 (40 C.F.R. § 260.10)); surface im-poundments (“natural topographic depression^], man-made excavation[s], or diked area[s] ... designed to hold an accumulation of liquid wastes or wastes containing free liquids,” id.); and land treatment facilities (facilities “at which hazardous waste is applied onto or incorporated into the soil surface,” id.). See 43 Fed.Reg. 58,986, 59,-005 (proposed 40 C.F.R. § 250.43-8) (landfills and surface impoundments); and id. 58,990, 59,014 (proposed 40 C.F.R. § 250.-45-5(e)) (land treatment facilities). The EPA proposed groundwater and leachate monitoring requirements for both landfills and surface impoundment facilities. See 43 Fed.Reg. 59,005-06 (proposed 40 C.F.R. § 250.43-8). Groundwater monitoring involves the analysis of water quality in the earth’s saturated zone, see id. 58,997 (proposed 40 C.F.R. § 250.41(38)), i.e., “that part of the earth’s crust in which all voids are filled with water,” id. 58,998 (proposed 40 C.F.R. § 250.41(76)). Leach-ate monitoring, on the other hand, requires the analysis of water quality in the earth’s unsaturated zone (zone of aeration), see id. 58,997 (proposed 40 C.F.R. § 250.41(51)), i.e., “the zone between the land surface and the nearest saturated zone, in which the interstices are occupied partially by air,” id. 58,999 (proposed 40 C.F.R. § 250.-41(93)). Although it recognized that the “technology of leachate monitoring [was] still being refined,” id. 58,986, the EPA defended its proposed requirement as an important means of “providpng] an early warning that groundwater contamination may occur.” Id. According to the Agency, “[gjroundwater monitoring alone does not sufficiently protect the environment because the leak must move through and cause extensive contamination of the [unsaturated zone] before it reaches and contaminates the groundwater.” Id. 1. Proposed Regulations The proposed regulations discussed monitoring requirements for land treatment facilities separately, and specified the use of soil coring. See 43 Fed.Reg. 59,014 (proposed 40 C.F.R. § 250.45-5(e)). Like leach-ate monitoring, soil-core monitoring examines soil in the unsaturated zone. But while leachate monitoring detects waste contaminants passing through the soil, soil-core monitoring detects those that remain in the soil. See 45 Fed.Reg. 33,207. The EPA also requested comments on, but did not propose, a groundwater monitoring requirement at land treatment facilities. 43 Fed.Reg. 58,990. Groundwater monitoring would probably be unnecessary, the EPA explained, because “soil monitoring will detect [hazardous waste] migration long before groundwater is threatened.” Id. 2. Final Rules The final rules required only groundwater monitoring at landfills and surface im-poundments. See 45 Fed.Reg. 33,239-40 (40 C.F.R. § 265.90). Unlike the proposed regulations, they did not require leachate monitoring at these facilities because of the “technical problems” associated with its implementation. Id. 33,191. According to the EPA, [available leachate monitoring technology generally involves the placement of probes (lysimeters) beneath the disposal facility. Since each probe is not generally capable of monitoring a large area, many of them would have to be placed under a facility in order to detect a localized flaw in the landfill design. It may not be possible to place such devices below an existing landfill or surface im-poundment without completely removing the waste and redesigning the facility. Moreover, once such a system is in place, the probes tend to fail over time due to deterioration or plugging. It is difficult to determine when such a failure occurs and, if discovered, the damage is generally irreparable. Id. In contrast, the final rules required that land treatment facilities utilize soil-core and leachate, as well as groundwater, monitoring systems. See 45 Fed.Reg. 33,239-40 (40 C.F.R. § 265.90), and 33,248 (40 C.F.R. § 265.278). According to the EPA, all three testing systems were necessary “to accurately determine whether the complex processes involved in land treatment are, in fact, occurring, and whether contaminants are migrating to ground water.” Id. 33,-207. The EPA explained that it was requiring both types of unsaturated zone monitoring because they perform complementary functions: Soil core monitoring is useful in determining the extent to which the hazardous wastes are being attenuated and broken down in the soil. [Leachate] monitoring is a necessary complementary or back-up system to assure that the absence of a hazardous waste constituent in the soil core sample indicates a breakdown of the waste rather than merely the rapid migration of the waste material through the soil matrix. Id. The EPA also explained why leachate monitoring was required at land treatment facilities, despite its rejection of such a requirement for landfills and surface im-poundments: [Leachate] monitoring is more easily achieved at land treatment sites than at landfills or surface impoundments. Ly-simeters or similar devices which measure [leachate] contamination can be installed at land treatment facilities in the area where waste has been applied. The relatively shallow depth of waste application at land treatment facilities allows lysimeters to be replaced, at both existing and new facilities, when they become clogged or otherwise nonfunctional. Furthermore, land treatment facilities typically do not have liners which would interfere with the placement of lysime-ters. Id. Beginning on July 18, 1980, the API submitted a series of post-promulgation comments criticizing the final rule’s leachate monitoring requirement for land treatment facilities. See Appendix to Reply Brief for Petitioner API. The API argued that leachate monitoring was unnecessary for land treatment of petroleum wastes. See id. at A-3 and A-4. It also identified a number of problems associated with the use of lysimeters at land treatment facilities: 1) The top of the lysimeter pipe will project above the ground and form an obstacle to efficient tilling and spreading of waste. A high probability of physical damage to the spreading equipment and to the lysimeters will exist. Even buried lysimeters are subject to damage from the plowing operation[;] 2) Consulting firms with experience in the area report problems with use of lysimeters such as frequent plugging and surface water infiltration down the outside of the pipe[;] 3) Even though it is possible to replace lysimeters when they become plugged or damaged, there may be little justification under many circumstances for the continuing expense of replacement. Id. at A-4 and A-5. The EPA neither responded to these comments nor modified the interim final rule. 3. Adequacy of Notice As we explained in our discussion of the mixture and derived-from rules, when a final rule bears little resemblance to the one proposed, the parties are deprived of their APA rights to notice and comment. See Small Refiner, 705 F.2d at 547. When a final rule is a logical outgrowth of the proposal, on the other hand, the APA’s notice-and-comment provisions are satisfied, and procedural challenges based thereon must fail. Id. “[T]he test, imperfectly captured in the phrase ‘logical outgrowth,’ ” id. at 548-49, is whether parties “should have anticipated” leachate monitoring at land treatment facilities. Id. at 549. In its proposed regulations, the EPA explained that it was considering a leachate monitoring requirement for surface im-poundments and landfills, even though the relevant technology was still evolving. See 43 Fed.Reg. 58,986. It also made clear, however, that its proposals for surface im-poundments and landfills did not apply to land treatment facilities: In the Agency’s words, “[m]onitoring at [land treatment facilities] is treated separately.” Id. In the separate section discussing these facilities, the EPA indicated that it would require soil-core monitoring but not groundwater monitoring. While it asked for comments on whether groundwater monitoring would be desirable at land treatment facilities, id. 58,990, the EPA did not mention leachate monitoring anywhere in the section. We conclude that the EPA did not adequately forewarn parties that leachate monitoring might be imposed. As both the proposed regulations and final rules reveal, the three types of proposed monitoring requirements are quite different: Leachate and groundwater monitoring test different subterranean zones (unsaturated and saturated, respectively), and soil-core and leach-ate monitoring perform different analyses within the same zone. A proposal to require one type of monitoring does not imply an intent to require another; nor does a proposal to require one kind of monitoring at landfills and surface impoundments imply an intent to require that same kind at land treatment facilities. In contrast to surface impoundments and landfills, which are enclosed facilities designed primarily to contain hazardous waste, see 45 Fed.Reg. 33,202; 33,209-10, land treatment facilities use soil as a medium to treat the waste and typically lack liner systems. Id. 33,205. As a consequence, land treatment facilities likely pose different environmental hazards than do landfills and surface impoundments and, as the final rules suggest, may also require different monitoring systems. The problem here, however, is that interested parties had no notice that one of these systems might be leachate monitoring. The EPA nevertheless purports to find adequate notice in various parts of the proposed regulations. It points, first, to two passages in its discussion of land treatment facilities: the request for comments on “whether groundwater monitoring is desirable at [land treatment facilities],” as well as on “all aspects of the soil monitoring requirements,” 43 Fed.Reg. 58,990 (emphasis added); and the request for comments on the “adequacy, s