Opinion for the Court filed by Circuit Judge D.H. GINSBURG.

D.H. GINSBURG, Circuit Judge:

Petitioners Chemical Waste Management, Inc. and Waste Management of North America seek review of Environmental Protection Agency regulations, 40 C.F. R. Part 24 (1988), that establish informal procedures for administrative hearings concerning the issuance of corrective action orders under § 3008(h) of the Resource Conservation and Recovery Act (RCRA), as modified by the Hazardous and Solid Waste Amendments of 1984. 42 U.S.C. § 6928(h) (1982 & Supp.1985). We conclude that the regulations represent a reasonable interpretation of an ambiguous statutory provision and are not, on their face, inconsistent with the requirement of due process. Accordingly, we deny the petition for review.

I. Background

Congress enacted RCRA in 1976 to establish a comprehensive program for regulation of hazardous waste management and disposal. The statute requires generally that the operator of any hazardous waste treatment, storage, or disposal facility obtain a permit, RCRA § 3005, 42 U.S.C. § 6925, but facilities in existence as of 1980 may continue to operate as “interim facilities” pending agency action on their permit applications, RCRA § 3005(e), 42 U.S.C. § 6925(e).

A. Formal Adjudication under Part 22.

Subsection (a) of RCRA § 3008 authorizes EPA to enter orders assessing civil penalties, including suspension or revocation of permits, for violation of RCRA regulations. 42 U.S.C. § 6928(a). Subsection (b) provides that, upon request made within thirty days of the issuance of a subsection (a) order, EPA “shall promptly conduct a public hearing.” Accordingly, the agency is authorized to “issue subpoenas for the attendance and testimony of witnesses and the production of relevant papers, books, *222and documents, and may promulgate rules for discovery procedures.” RCRA § 3008(b), 42 U.S.C. § 6928(b).

In 1978, EPA promulgated procedural regulations to implement the “public hearing” provision of subsection (a). 40 C.F.R. Part 22. These procedures conform to the provisions of the Administrative Procedure Act for formal adjudication. 5 U.S.C. §§ 556 & 557. For example, an Administrative Law Judge presides at the hearing, 40 C.F.R. § 22.03(a), and each party has the right to call and to cross-examine witnesses, 40 C.F.R. § 22.22(b).

In the preamble accompanying these regulations, EPA explained its selection of formal adjudicatory procedures. Although, in EPA’s view, there are “many cases” in which the term “public hearing” should not be read to require formal adjudicatory procedures, EPA concluded that “the nature of the decision at issue in [subsection (a) ] cases indicates ... that such formal procedures were probably intended.” 43 Fed. Reg. 34738 (1978). In such cases, the agency “will be accusing someone of violating established legal standards through their past conduct, and will be seeking to impose a sanction for it____ In addition, the facts at issue will be specific ones involving the past conduct of regulated persons.” Id.

B. Informal Adjudication Under Part U

In the Hazardous and Solid Waste Amendments of 1984, Congress added to § 3008 a new subsection (h), authorizing the Administrator of EPA to issue “an order requiring corrective action” whenever he “determines that there is or has been a release of hazardous waste into the environment” from an interim facility. RCRA § 3008(h)(1), 42 U.S.C. § 6928(h)(1). Such orders must indicate “the nature of the required corrective action or other response measure, and ... specify a time for compliance,” and may include suspension or revocation of the facility’s authorization to operate as an interim facility. RCRA § 3008(h)(2), 42 U.S.C. § 6928(h)(2). The Administrator may assess a civil penalty of up to $25,000 per day for noncompliance with a corrective action order. Id. The 1984 Amendments also modified subsection (b) to make it clear that those subject to corrective action orders under the new subsection (h) have the right to a “public hearing.”

To govern subsection (h) hearings, EPA promulgated the procedural regulations here under review, 40 C.F.R. Part 24. Those rules specifically provide that the formal adjudicatory procedures of Part 22 shall be applicable only to challenges to subsection (h) corrective action orders that include a suspension or revocation of interim status or an assessment of civil penalties for noncompliance. 40 C.F.R. § 24.01. If the order calls upon the interim facility operator merely to undertake an investigation or to do so in combination with interim corrective measures, then, depending upon the burden entailed by such measures, the agency will use either the informal adjudicatory procedures provided in Subpart B of Part 24 (for interim corrective measures that are “neither costly nor technically complex,” 40 C.F.R. § 24.80) or those in Subpart C of Part 24.

The procedures in Subparts B and C are substantially similar insofar as is relevant to this case. The crucial point is that both subparts set forth informal rather than formal adjudicatory procedures. Under either subpart, the operator of a hazardous waste facility may submit written information and argument for inclusion in the record, 40 C.F.R. §§ 24.10(b) & 24.14(a)(1); make an oral presentation at the hearing itself, 40 C.F.R. §§ 24.11 & 24.15(a); and be assisted at hearing by legal and technical advisors, id. Direct examination and cross-examination of witnesses is not permitted, but the Presiding Officer may direct questions to either party. Id. The Presiding Officer is to be either “the Regional Judicial Officer ... or another attorney employed by the Agency, who has had no prior connection with the case, including performance of any investigative or prosecuting functions.” 40 C.F.R. §§ 24.09 & 24.13(a). With respect to both Subpart B and Subpart C proceedings, EPA, when issuing a corrective action order, shall deliver to the operator “all relevant doc*223uments and oral information (which has been reduced to writing), which the Agency considered in the process of developing and issuing the order, exclusive of privileged internal communications.” 40 C.F.R. § 24.03(b).

The Presiding Officer is to review the record and to file a recommended decision with the EPA Regional Administrator, 40 C.F.R. §§ 24.12 & 24.17. The Regional Administrator, in turn, is to receive comments from the parties and to render a final decision, 40 C.F.R. § 24.18, from which an aggrieved party may seek judicial review under the APA.

II. Chevron Analysis

Petitioners argue initially that the informal procedures of Part 24 are inconsistent with the intent of Congress in enacting and amending § 3008. To this end, petitioners make three specific contentions: first, that the language of subsection (b), as interpreted by EPA in its 1978 implementing regulations, requires formal procedures in all subsection (h) adjudications; second, that the legislative history of the 1984 Amendments demonstrates Congress’s intention that EPA use the same formal procedures for the issuance of the new subsection (h) orders as the agency had theretofore established for the issuance of subsection (a) orders; and, third, that precedent in this circuit erects a presumption that when Congress refers to an adjudication as a “hearing,” it intends that formal procedures be used.

We approach petitioners’ arguments within the framework that the Supreme Court decreed in Chevron U.S.A. v. Natural Resources Defense Council, 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984), for judicial review of an agency’s interpretation of a statute under its administration. At the outset, we ask whether “Congress has directly spoken to the precise question at issue,” id. at 842, 104 S.Ct. at 2781; if so, then we “must give effect to the unambiguously expressed intent of Congress” and may not defer to a contrary agency interpretation, id. at 842-43, 104 S.Ct. at 2781-82. If the statute is “silent or ambiguous with respect to the specific issue,” however, we proceed to ask “whether the agency’s answer is based on a permissible construction of the statute,” id. at 843, 104 S.Ct. at 2782; if so, then we must defer to the agency’s construction.

A. Chevron Step One.

Before turning to petitioners’ principal arguments based on the requirement of a “public hearing,” we may briefly dispose of a related argument based on the provision in subsection (b) that the EPA “may promulgate rules for discovery procedures.” According to petitioners, this nominally permissive statement implies that Congress contemplated, and that the agency must therefore provide, formal procedures in which discovery plays a part. In response to a similar contention at the rule-making stage, EPA read subsection (b) to “suggest[] that [a] hearing which did not contain this feature most commonly associated with adjudicatory hearings would also be acceptable.” 53 Fed.Reg. at 12258. Given the implicit but presumably intentional distinction in the statute between things that the agency “shall” do (initiate a “public hearing” upon request) and those that it “may” do (promulgate discovery rules), we reject the argument that the statute compels the use of procedures involving discovery and do not reach the suggested inference from discovery to formal hearing procedures generally.

1. Prior Agency Interpretation. As to petitioners’ argument based upon the hearing requirement, we observe initially that the statutory language, taken alone, does not show that Congress “has directly spoken to the precise question at issue.” Subsection (b) requires a “public hearing” but does not, by its terms, indicate whether Congress intended that formal or informal hearing procedures be used. Petitioners claim, however, that in 1978 EPA interpreted the phrase “public hearing” to require formal adjudication when it promulgated procedures to govern hearings on orders issued under subsection (a). We think they misread the record in this regard.

*224Although EPA did believe that Congress “intended” it to use formal procedures for hearings on orders under subsection (a), the agency made clear that this conclusion rested upon the particular nature of the issues raised by such orders, not upon the force of the statutory language alone. 43 Fed.Reg. 34738 (1978). EPA thus did not adopt the view that the reference to a “public hearing” in subsection (b) necessarily or always imposes a requirement of formal procedures. Even if EPA had taken that position, moreover, it would remain free to change its interpretation in order to permit the use of informal procedures to implement the 1984 Amendments, provided that its new interpretation is otherwise legally permissible and is adequately explained. See United Technologies Corp. v. EPA, 821 F.2d 714, 723 (D.C.Cir.1987). We therefore turn to petitioners’ argument based upon the 1984 Amendments.

2. The 1984 Amendments. When Congress authorized EPA to issue corrective action orders under subsection (h), it also extended the right to a “public hearing” under subsection (b) to encompass such orders. According to petitioners, Congress’s decision to apply the existing hearing provision of subsection (b) — at a time when EPA had only formal adjudicatory procedures in effect — shows that Congress wished also to apply those formal procedures to hearings on orders issued pursuant to the new subsection (h). To support this inference, petitioners rely heavily on a statement by Senator Chafee, a sponsor of the 1984 Amendments, indicating that the “procedures set forth in subsection (b) are made applicable to orders issued under this new subsection [ (h) ].” 130 Cong.Rec. S39175 (daily ed. July 15, 1984) (emphasis added).

The short answer to petitioners’ argument is that the Senator referred not to the procedures set forth in Part 22 of EPA’s regulations implementing subsection (b), but to the “procedures set forth in” the statutory subsection itself. Absent a more specific reference to the formal procedures of Part 22, we may not infer that Senator Chafee and his colleagues intended to en-graft those regulations onto § 3008. See AFL-CIO v. Brock, 835 F.2d 912, 915 (D.C. Cir.1987) (“express congressional approval of an administrative interpretation [required] if it is to be viewed as statutorily mandated”).

Without distinguishing the AFL-CIO case, petitioners maintain that Senator Chafee’s failure to refer expressly to Part 22 is “immaterial,” since he did cite “the dispositive statutory [subjection.” This contention would be relevant if the language of the statute made clear the type of procedures intended. As we have seen, however, that is not the case. Absent a reference to Part 22, Senator Chafee’s statement remains, at best, ambiguous.

3. Circuit Precedent. Petitioners point to our statement in a footnote in Union of Concerned Scientists v. U.S. NRC, 735 F.2d 1437, 1444 n. 12 (D.C.Cir.1984) (UCS), that “when a statute calls for a hearing in an adjudication the hearing is presumptively governed by ‘on the record’ procedures,” notwithstanding omission of the phrase “on the record” in the statute. See also Seacoast Anti-Pollution League v. Costle, 572 F.2d 872, 877 (1st Cir.1978); Marathon Oil v. EPA, 564 F.2d 1253, 1264 (9th Cir. 1977). For the reasons set out below, however, we decline to adhere any longer to the presumption raised in UCS.

For perspective, we note first that the very footnote cited by petitioners makes clear that the issue in that case was “whether the NRC can, in its discretion, bypass [a statutory] hearing requirement altogether on issues material to its licensing decisions,” and that “we refrain[ed] from holding outright that [the hearing provision in question there] requires ‘on the record’ hearings.” 735 F.2d at 1444 n. 12. Our statement about the presumption to that effect was therefore dicta. We did not actually rely on the presumption we announced, but rather inferred that Congress intended the use of formal adjudicatory procedures based both upon NRC’s unsuccessful efforts to convince Congress to do away with such procedures and upon NRC’s consistent position, over a twenty year period, that the statute required for*225mal procedures. Id. No such contextual circumstances exist here.

More important, UCS and its kin, Seacoast and Marathon, all predate the Supreme Court's decision in Chevron. Under that decision, it is not our office to presume that a statutory reference to a “hearing,” without more specific guidance from Congress, evinces an intention to require formal adjudicatory procedures, since such a presumption would arrogate to the court what is now clearly the prerogative of the agency, viz., to bring its own expertise to bear upon the resolution of ambiguities in the statute that Congress has charged it to administer. In effect, the presumption in UCS truncates the Chevron inquiry at the first step by treating a facially ambiguous statutory reference to a “hearing” as though it were an unambiguous constraint upon the agency. We will henceforth make no presumption that a statutory “hearing” requirement does or does not compel the agency to undertake a formal “hearing on the record,” thereby leaving it to the agency, as an initial matter, to resolve the ambiguity.*

While an agency might not be able reasonably to read a requirement that it conduct a “hearing on the record” to permit informal procedures in the converse situation to that presented here, an agency that reasonably reads a simple requirement that it hold a “hearing” to allow for informal hearing procedures must prevail under the second step of Chevron. As usual in cases involving Chevron’s second step, the court will evaluate the reasonableness of the agency’s interpretation using the normal tools of statutory interpretation — such as legislative history, structural inferences, or exceptional circumstances of the type presented in UCS.

B. Chevron Step Two.

In the alternative, petitioners contend that EPA failed to provide a reasoned explanation, as required under the “arbitrary or capricious” standard of APA § 706, 5 U.S.C. § 706(2)(A), to support its conclusion that corrective action orders under subsection (h) are amenable to informal adjudicatory procedures. Since it would clearly be unreasonable for the agency to resolve a statutory ambiguity to support an arbitrary result, petitioners’ position is functionally a Chevron step two contention that EPA’s interpretation of the statute is unreasonable. This is the issue joined.

Specifically, petitioners attack EPA’s claims that subsection (h) orders will pose fewer factual issues than do subsection (a) orders; that any factual issues that do arise can be resolved by considering documents and oral statements without need of trial-type examination of witnesses; and that informal procedures will allow the agency to respond more quickly to releases of hazardous waste.

1. The Number and Nature of Factual Issues. In its preamble accompanying the Part 24 regulations, EPA predicts that “[subsection] (h) cases will present fewer factual issues than the typical case involving an RCRA [subsection] (a) compliance order,” since “questions as to whether certain events or violations occurred, the timing of certain events/violations, the seriousness of the violation, [and] the economic benefit to respondent of the violation” will arise less frequently. 53 Fed.Reg. at 12257. In addition, EPA said that those factual issues that do arise “will relate almost entirely to technical (or policy) matters” that create “little need to establish witness veracity or credibility through observation of a witness’s demeanor on cross-examination” and therefore “can just as easily (perhaps more effectively) be resolved through analysis of the administrative record and the written submissions and oral statements of the parties.” Id.

Petitioners argue first that EPA has ignored the additional benefits — in terms of increased accuracy, for example — that formal procedures may bring to fact finding. Second, petitioners observe that some subsection (h) orders may involve issues that *226could be “susceptible to varying interpretations.” The agency may safely demur to these charges; neither of them undercuts the validity of its decision to establish procedures based on the typical subsection (h) order. The Part 24 regulations, furthermore, leave the Presiding Officer with a degree of discretion to tailor hearing procedures to the needs of the particular case, see, e.g., 40 C.F.R. §§ 24.11 & 24.15(a) (Sub-parts B & C) (Presiding Officer “may address questions” to either party); § 24.11 (Subpart B) (Presiding Officer “may ... allow technical and legal discussions and interchanges between the parties, including responses to questions to the extent deemed appropriate”); § 24.24(d) (Subpart C) (respondent may request permission to submit up to 25 written questions to EPA “concerning issues of material fact”), which should be adequate to meet precisely the problems petitioners anticipate, in the event that they ever arise.

2. Necessity for Prompt Response. The preamble to the notice promulgating Part 24 also refers to the seemingly obvious “need to respond quickly to releases of hazardous waste.” 53 Fed.Reg. at 12257. More specifically, in its brief to this court, EPA also quotes Senator Chafee’s statement, introducing the 1984 Amendments, that “[sjince there are some 8,000 interim facilities, compared to 115 permitted facilities, it is most appropriate and necessary to extend the corrective action requirement to interim status facilities and to provide the Administrator with the authority to impose such requirements quickly.” 130 Cong. Rec. S9175 (daily ed. July 25, 1984).

As petitioners point out, however, Senator Chafee and his colleagues were concerned not with delays in the adjudication of corrective action orders but, instead, with impediments to EPA’s regulation of interim facilities; prior to the 1984 Amendments, EPA was authorized to order corrective action only with respect to permitted facilities. See id.; H.R.Conf.Rep. No. 1133, 98th Cong. 110 (1984), U.S.Code Cong. & Admin.News 1984, pp. 5576, 5681. Subsection (h) was intended to allow EPA to order corrective action with respect to an interim facility without having to wait for it to complete the permitting process, which Senator Chafee expected would take ten years to cover all interim facilities. 130 Cong.Rec. S9175. Accordingly, EPA cannot rely upon the need for swift adjudication to justify its use of informal hearing procedures.

Nonetheless, we conclude that the agency has provided a reasonable explanation for its choice of informal procedures in Part 24, based on the number and nature of factual issues expected in a typical subsection (h) proceeding.

III. Due Process

Finally, petitioners contend that Part 24 on its face denies them due process of law, in violation of the Fifth Amendment to the Constitution. When evaluating such an attack on the procedures used by an administrative agency to deprive a person of property, we must consider: (1) “the private interest that will be affected by agency action”; (2) “the risk of an erroneous deprivation of such interest through the procedures used, and the probable value, if any, of additional or substitute procedural safeguards”; (3) “the Government’s interest including the function involved and the fiscal and administrative burdens that the additional ... procedural requirement would entail.” Mathews v. Eldridge, 424 U.S. 319, 335, 96 S.Ct. 893, 903, 47 L.Ed.2d 18 (1976). In short, the Supreme Court directs us to analyze the anticipated benefits to private interests and costs to the Government of the procedures allegedly required by the Due Process Clause.

A. Private Interests.

Petitioners claim that subsection (h) orders may, in some instances, require the operator of an interim facility to undertake investigations and corrective measures that can have “a multi-million dollar impact.” Petitioners offer no response, however, to EPA’s observation that, over the run of orders issued under subsection (h), the costs of corrective action will vary widely. 53 Fed.Reg. at 12257. In light of this variance, we find no fault in EPA’s decision *227to design its Part 24 procedures based on the stakes that it expects will be involved in the great majority of corrective action proceedings that entail neither suspension of interim authorization nor assessment of civil penalties. The possibility that these procedures might prove inadequate to safeguard the interest of the operator in a particular case involving costly investigations or corrective measures does not count for much in the calculus of benefits and costs we make when asked to strike down administrative procedures in a facial due process challenge.

B. Risk of Error.

Under the second Eldridge factor, petitioners point to two distinct sources of error in the new procedural regulations.

1. Lack of Substantive Standards. Petitioners initially observe that the 1984 Amendments to RCRA require EPA to develop standards for corrective action, RCRA § 3004(u), 42 U.S.C. § 6924(u), and that the agency has not yet done so. From this, petitioners infer that the Presiding Officer in a subsection (h) hearing will lack any substantive standards to guide his decision. EPA, on the other hand, points to three available sources of guidance: (1) regulations for corrective action upon the release of hazardous waste from land disposal units, 40 C.F.R. Part 264, Subpart F; (2) various agency “guidance documents to aid decisions on RCRA corrective action”; and (3) regulations for remedial actions under the Comprehensive Environmental Response, Compensation, and Liability Act, 40 C.F.R. Part 300. Since, in reply, petitioners do not question the utility of these sources, we accept EPA’s representation that, until such time as the agency promulgates standards specifically for corrective actions pursuant to § 3004(u), Presiding Officers will find in these sources standards adequate to guide their decisions.

2. Lack of Formal Adjudicatory Procedures. Petitioners renew their claim, this time as a matter of due process, that EPA must use formal adjudicatory procedures. Petitioners fail to explain how such procedures will significantly advance the accuracy of an adjudicative process in which the issues typically do not require determinations of witness credibility but turn instead upon technical data and policy judgments. In Eldridge itself, the Court states that such proceedings present less of a need for trial-type procedures. 424 U.S. at 343-44, 96 S.Ct. at 906-07.

According to petitioners, due process requires that an ALJ conduct a subsection (h) hearing. Petitioners are particularly critical of the provisions of Part 24 that allow agency attorneys to serve as Presiding Officers, provided only that they have “had no prior connection with the case, including the performance of any investigative or prosecuting functions.” 40 C.F.R. §§ 24.09 & 24.13(a). Petitioners fear that even a Presiding Officer who meets this condition may be influenced by “institutional biases and prosecutorial zeal”; indeed, the Presiding Officer might, for all that the regulation requires, be a subordinate of the prosecuting attorney within EPA’s internal hierarchy.

The Supreme Court has held that even the combination, in a single administrative decision maker, of investigative and adjudicative functions — which the EPA regulations plainly forbid — “does not, without more, constitute a due process violation”; rather, “the special facts and circumstances of the case ... [must indicate] that the risk of unfairness is intolerably high.” Withrow v. Larkin, 421 U.S. 35, 58, 95 S.Ct. 1456, 1470, 43 L.Ed.2d 712 (1975). Moreover, in challenging a particular adjudication on this ground, the complaint must “overcome the presumption of honesty and integrity in those serving as adjudicators” by showing “a risk of actual bias or prejudgment.” Id. at 47, 95 S.Ct. at 1464. In light of Withrow’s stringent standard for an “as applied” attack on procedures that allow the combination of investigative and adjudicative functions, we find no basis for petitioners’ broad facial challenge, which by its nature deprives us of the particularized information necessary to evaluate a claim of probable bias.

Finally, petitioners attack the regulations on the ground that the Presiding Officer will be unable to resolve the intricate tech*228nical issues that may arise in a subsection (h) proceeding. They do not, however, explain why an agency attorney would be any less equal to that task than would be the ALT they prefer.

In sum, petitioners have shown little if any avoidable risk of error arising from the procedural regulations they challenge.

C. The Government’s Interest.

On the Government’s side of the Eldridge ledger, EPA estimates that “roughly half of the cost to the Agency of participating in full adjudicatory hearings will be saved by holding hearings under the [informal Part 24] procedures.” 53 Fed.Reg. at 12257. By contrast, the cost of formal procedures, according to EPA, would “significantly impair [its] ability to enforce” subsection (h). Id. at 12258.

Petitioners counter that the failure to use formal procedures will increase the risk that a court will subsequently find the administrative record inadequate for judicial review, thereby necessitating a costly remand for additional proceedings. Along similar line, petitioners claim that technical personnel involved in the hearing will produce “better” reports when they “know that their work may be tested” by formal procedures. Petitioners neglect, however, to compare the asserted increase in the cost of occasional remands against the substantial (and undisputed) savings to the agency that will accrue in all other cases. Without any experience to go by, we cannot infer that the effects described by petitioners will be more than a modest offset to the savings EPA will achieved by using informal procedures.

******

In sum, the cost-benefit analysis mandated by Eldridge indicates that, to the modest extent that EPA’s Part 24 regulations do implicate the private interest in avoiding the expense of unnecessary corrective actions, formal procedures do not promise a sufficient lowering of the risk of error to justify their significant expense to the Government. We therefore hold that the Part 24 regulations are not inconsistent on their face with the requirements of due process.

We suppose that the absence of formal safeguards could prove troublesome in a case that involved both high financial stakes to the operator and either substantive issues that would benefit greatly from development through trial-type procedures, or a Presiding Officer with “actual bias.” That case has not yet arisen, however. From the face of the Part 24 regulations, neither petitioners nor we have any indication of how the agency will apply them in particular instances. There is no reason to doubt, however, that by being reasonably sensitive to the needs of each case, EPA can avoid the problems posited by petitioners.

IV. Conclusion

Because we conclude that the procedures for hearings on corrective action orders under subsection (h) reflect a reasonable interpretation of . an ambiguous statutory mandate and are not, on their face, inconsistent with the constitutional requirement of due process, the petition for review is

Denied.

SELYA, Circuit Judge.

USGen New England, Inc., now Dominion Energy Brayton Point, LLC (Dominion), filed suit against the U.S. Environmental Protection Agency, its administrator, and its regional office (collectively, the EPA), alleging that the EPA failed to perform a non-discretionary duty when it refused to grant Dominion’s request for a formal evidentia-ry hearing after issuing a proposed final National Pollution Discharge Elimination System (NPDES) permit. The district court dismissed the case for want of subject matter jurisdiction. On appeal, the central question presented concerns the effect of this court’s decision in Seacoast Anti-Pollution League v. Costle, 572 F.2d 872 (1st Cir.1978), in light of the Supreme Court’s subsequent decision in Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984). Concluding, as we do, that Seacoast does not control, we affirm the judgment below.

I. BACKGROUND

Dominion owns an electrical generating facility in Somerset, Massachusetts (the station). The station opened in the 1960s and, like most power plants of its era, utilizes an “open-cycle” cooling system. Specifically, the station withdraws water from the Lees and Taunton Rivers, circulates that water through the plant’s generating equipment as a coolant, and then discharges the water (which, by then, has attained an elevated temperature) into Mount Hope Bay.

The withdrawals and discharges of water are regulated by the Clean Water Act (CWA), 33 U.S.C. §§ 1251-1387. For the last three decades, these actions have been authorized by a series of NPDES permits issued by the EPA pursuant to section 402(a) of the CWA. See id. § 1342(a). The standards incorporated into those permits are determined under the thermal variance procedures laid out in section 316(a). See id. § 1326(a).

In 1998, the station applied for renewal of its NPDES permit and thermal variance authorization. The EPA issued a proposed final permit on October 6, 2003, in *14which it rejected the requested thermal variance. On November 4, Dominion sought review before the Environmental Appeals Board (the Board), see 40 C.F.R. § 124.19(a) (authorizing Board review), and asked for an evidentiary hearing. The Board accepted the petition for review but declined to convene an evidentiary hearing. See In re USGen New Eng., Inc. Brayton Point Station, 11 E.A.D. 525, 525 (EAB July 23, 2004).

On August 11, 2004, Dominion notified the EPA of its intent to file a citizen’s suit under section 505(a)(2) of the CWA, 33 U.S.C. § 1365(a)(2), to compel the Board to hold an evidentiary hearing. Receiving no reply, Dominion proceeded to file its complaint in the United States District Court for the District of Massachusetts. The EPA moved to dismiss.

The district court granted the motion on jurisdictional grounds. See Fed.R.Civ.P. 12(b)(1). In a bench decision, it concluded that it was without subject matter jurisdiction because the suit, though billed as a citizen’s suit, constituted a direct challenge to the EPA’s hearing rule and, thus, came within the exclusive jurisdiction of the circuit court under 33 U.S.C. § 1369(b)(1)(E). This timely appeal followed.1

II. THE LEGAL LANDSCAPE

We set the stage for our substantive discussion by undertaking a brief review of the legal rules that frame the controversy at hand.

Before the EPA either issues an NPDES permit or authorizes a thermal variance,2 it must offer an “opportunity for public hearing.” 33 U.S.C. §§ 1326(a), 1342(a). No definition of “public hearing” is contained within the four corners of the CWA.

The Administrative Procedure Act (APA), 5 U.S.C. § 551 et seq., is also part of the relevant legal landscape. Most pertinent here are those sections that combine to describe the procedures for formal administrative adjudications. See id. §§ 554, 556, 557.. These procedures apply “in every case of adjudication required by statute to be determined on the record after opportunity for an agency hearing.” Id. § 554(a). The APA does not directly address whether these procedures apply when a statute simply calls for an “opportunity for public hearing” without any specific indication that the hearing should be “on the record.”

In Seacoast, this court interpreted “public hearing” (as used in sections 402(a) and 316(a) of the CWA) to mean “evidentiary hearing” — in other words, a hearing that comports with the APA’s requirements for a formal adjudication. 572 F.2d at 878. Examining the legislative history of the APA, we adopted a presumption that “unless a statute otherwise specifies, an adjudicatory hearing subject to judicial review must be [an evidentiary hearing] on the record.” Id. at 877. Applying that presumption to the CWA, we concluded that “the statute certainly does not indicate *15that the determination need not be on the record.” Id. at 878 (emphasis in original).

So viewed, Seacoast established a rebut-table presumption that, in the context of an adjudication, an organic statute that calls for a “public hearing” should be read to require an evidentiary hearing in compliance with the formal adjudication provisions of the APA. Two other circuit courts reached the same conclusion, albeit through different reasoning. See Marathon Oil Co. v. EPA, 564 F.2d 1253, 1264 (9th Cir.1977); U.S. Steel Corp. v. Train, 556 F.2d 822, 833-34 (7th Cir.1977). Acquiescing in this construction, the EPA promulgated regulations that memorialized the use of formal evidentiary hearings in the NPDES permit process. See NPDES; Revision of Regulations, 44 Fed.Reg. 32,-854, 32,938 (June 7,1979).

In 1984, a sea change occurred in administrative law and, specifically, in the interpretation of organic statutes such as the CWA. The Supreme Court held that “[w]hen a court reviews an agency’s construction of the statute which it administers,” the reviewing court first must ask “whether Congress has directly spoken to the precise question at issue.” Chevron, 467 U.S. at 842, 104 S.Ct. 2778. If Congress’s intent is clear, that intent governs — both the court and the agency must give it full effect. Id. at 842^13, 104 S.Ct. 2778. If, however, Congress has not directly addressed the question and the agency has stepped into the vacuum by promulgating an interpretive regulation, a reviewing court may “not simply impose its own construction on the statute,” but, rather, ought to ask “whether the agency’s answer is based on a permissible construction of the statute.” Id. at 843, 104 S.Ct. 2778.

This paradigm, sometimes called the Chevron two-step, increases the sphere of influence of agency action. If congressional intent is unclear and an agency’s interpretation of a statute that it administers is reasonable, an inquiring court must defer to that interpretation. See id. at 843-44, 104 S.Ct. 2778. That is so even if the agency’s interpretation is not the one that the court considers to be the best available interpretation. See id. at 843, 104 S.Ct. 2778.

Armed with the Chevron decision and a presidential directive to streamline regulatory programs, see Remarks on Regulatory Reform, 31 Weekly Comp. Pres. Doc. 278 (Feb. 21, 1995), the EPA advanced a proposal to eliminate formal evidentiary hearings from the NPDES permitting process. See Amendments to Streamline the NPDES Program Regulations: Round Two, 61 Fed.Reg. 65,268, 65,276 (Dec. 11, 1996). In due course, the EPA adopted that proposal as a final rule. See Amendments to Streamline the NPDES Program Regulations: Round Two, 65 Fed.Reg. 30,-886, 30,900 (May 15, 2000).

This revision depended heavily on a Chevron analysis. The agency began by “finding no evidence that Congress intended to require formal evidentiary hearings or that the text [of section 402(a) ] precludes informal adjudication of permit review petitions.” Id. at 30,896. Then, it weighed the risks and benefits of employing informal hearing procedures for NPDES permit review, “determining that these procedures would not violate the Due Process Clause.” Id. Finally, it “concluded that informal hearing procedures satisfy the hearing requirement of section 402(a).” Id.

It was under this new regulatory scheme that the EPA considered Dominion’s request to renew its NPDES permit and to authorize a thermal variance. Thus, it was under this scheme that the EPA denied Dominion’s request for an evidentiary hearing.

*16III. ANALYSIS

The court of appeals reviews a dismissal for want of subject matter jurisdiction de novo. Gabriel v. Preble, 396 F.3d 10, 12 (1st Cir.2005). In doing so, the court accepts the well-pleaded factual allegations of the plaintiffs complaint and indulges all reasonable inferences in the plaintiffs favor. Muniz-Rivera v. United States, 326 F.3d 8, 11 (1st Cir.2003). The appellate court is not wedded to the lower court’s reasoning, but may affirm the order of dismissal on any ground fairly presented by the record. See InterGen N.V. v. Grina, 344 F.3d 134, 141 (1st Cir.2003).

Here, Dominion’s claim on appeal rests on the premise that it has satisfied the jurisdictional requirements for a citizen’s suit under section 505(a)(2) of the CWA. Subject to a notice requirement— suit may not be commenced “prior to sixty days after the plaintiff has given notice of such [proposed] action,” 33 U.S.C. § 1365(b)(2) — the statute invoked by Dominion grants federal district courts jurisdiction over any citizen’s suit brought “against the Administrator [of the EPA] where there is alleged a failure of the Administrator to perform any act or duty under [the CWA] which is not discretionary,” id. § 1365(a)(2). There is no question but that Dominion satisfied the applicable notice requirement. The crux of the case, therefore, is whether Dominion has pleaded the flouting of a non-discretionary duty.

One thing is crystal clear: on their face, the current EPA regulations do not establish a non-discretionary duty to provide the evidentiary hearing that Dominion seeks. Prior to the date of Dominion’s request, the EPA vitiated the preexisting rule introducing evidentiary hearings into the NPDES permitting process. See 40 C.F.R. § 124.21(b) (explaining that the “EPA eliminated the previous requirement for NPDES permits to undergo an eviden-tiary hearing after permit issuance ... on June 14, 2000”). Dominion concedes this fact, but nonetheless relies on Seacoast as the source of a non-discretionary duty to convene an evidentiary hearing.

This reliance is misplaced. Even if Seacoast established a non-discretionary duty for section 505(a)(2) purposes when it was decided' — a matter upon which we need not opine — Dominion’s position ignores two important post-Seacoast changes in the legal landscape: the Supreme Court’s decision in Chevron and the agency’s subsequent promulgation of the current “no evidentiary hearing” rule.

We anticipated this situation in Citizens Awareness Network, Inc. v. United States, 391 F.3d 338 (1st Cir.2004), in which we noted that “while the type of hearing required by a statute turns on congressional intent, Chevron adds a new dimension, requiring that the agency’s reasonable interpretation be accorded deference if there is any ambiguity as to that intent.” Id. at 348 n. 4. We also recognized Chevron’s possible ramifications for Seacoast, but did not have the occasion to confront the issue squarely. See id. (reserving the question “[t]o what extent (if at all) [Chevron ] erodes Seacoast’s rationale”). Now, with guidance from the Supreme Court’s last term lighting our path, we address the matter and conclude that, as to the CWA’s public hearing language, the Chevron doctrine trumps the potential application of stare decisis principles.

For present purposes, the critical precedent is National Cable & Telecommunications Ass’n v. Brand X Internet Services, — U.S. -, 125 S.Ct. 2688, 162 L.Ed.2d 820 (2005). There, the Court examined the relationship between the stare decisis effect of an appellate court’s statutory interpretation and the Chevron deference *17due to an administrative agency’s subsequent, but contrary, interpretation. Echoing Chevron, the Court reiterated that “Hilling [statutory] gaps ... involves difficult policy choices that agencies are better equipped to make than courts.” Id. at 2699. Then, concluding that Chevron’s application should not turn on the order in which judicial and agency interpretations issue, the Justices held squarely that “[a] court’s prior judicial construction of a statute trumps an agency construction otherwise entitled to Chevron deference only if the prior court decision holds that its construction follows from the unambiguous terms of the statute and thus leaves no room for agency discretion.” Id. at 2700. This approach “hold[s] judicial interpretations contained in precedents to the same demanding Chevron ... standard that applies if the court is reviewing the agency’s construction on a blank slate.” Id.

Brand X demands that we reexamine pre-Chevron precedents through a Chevron lens. The Chevron two-step applies. At the first step, a court “must look primarily to the plain meaning of the statute, drawing its essence from the particular statutory language at issue, as well as the language and design of the statute as a whole.” Strickland v. Comm’r, Me. Dep’t of Human Servs., 48 F.3d 12, 16 (1st Cir. 1995) (citation and internal quotation marks omitted). At this step, the court may “examine the legislative history, albeit skeptically, in search of an unmistakable expression of congressional intent.” Id. at 17. If the precedent at issue finds clarity at step one — that is, if the holding of the case rests on a perception of clear and unambiguous congressional intent — that precedent will govern. See Brand X, 125 S.Ct. at 2700. If, however, the precedent operates at Chevron step two — that is, if the case holds, in effect, that congressional intent is less than pellucid and proceeds to choose a “best reading” rather than “the only permissible reading,” id. at 2701 (emphasis in original) — its stare decisis effect will, through Chevron deference, yield to a contrary but plausible agency interpretation, see id. at 2700.

Once this mode of analysis is understood and applied, Dominion’s argument collapses. Seacoast simply does not hold that Congress clearly intended the term “public hearing” in sections 402(a) and 316(a) of the CWA to mean “evidentiary hearing.” To the contrary, the Seacoast court based its interpretation of the CWA on a presumption derived from the legislative history of the APA — a presumption that would hold sway only in the absence of a showing of a contrary congressional intent. Seacoast, 572 F.2d at 877-78. In other words, the court resorted to the presumption only because it could find no sign of a plainly discernible congressional intent. Id. at 878. A statutory interpretation constructed on such a negative finding is antithetic to a conclusion that Congress’s intent was clear and unambiguous.

The short of it is that the Seacoast court, faced with an opaque statute, settled upon what it sensibly thought was the best construction of the CWA’s “public hearing” language. Such a holding is appropriate at step two of the Chevron pavane, not at step one. Consequently, under Brand X, Seacoast must yield to a reasonable agency interpretation of the CWA’s “public hearing” requirement. See Brand X, 125 S.Ct. at 2700.

The only piece left to this puzzle is to confirm that the EPA’s new regulations are, in fact, entitled to Chevron deference. This inquiry is a straightforward one. As our earlier discussion suggests (and as the Seacoast court correctly deduced), Congress has not spoken directly to the precise question at issue here. See, e.g., United States v. Fla. E. Coast Ry. Co., 410 U.S. *18224, 239, 93 S.Ct. 810, 35 L.Ed.2d 223 (1973) (“The term ‘hearing’ in its legal context undoubtedly has a host of meanings.”); Chem. Waste Mgmt., Inc. v. U.S. EPA 873 F.2d 1477, 1480-82 (D.C.Cir. 1989) (concluding that Congress’s intent behind the words “public hearing” in section 3008 of the RCRA was ambiguous for Chevron purposes). Accordingly, we must defer to the EPA’s interpretation of the CWA as long as that interpretation is reasonable. See Chevron, 467 U.S. at 843-44, 104 S.Ct. 2778.

In this instance, the administrative interpretation took into account the relevant universe of factors. See 65 Fed.Reg. at 30,898-30,900 (considering “(1) [t]he private interests at stake, (2) the risk of erroneous decision-making, and (3) the nature of the government interest,” and concluding that its new regulation was a reasonable interpretation of the CWA); see also Chem. Waste Mgmt., 873 F.2d at 1483 (concluding that the EPA’s choice of informal adjudicatory procedures under RCRA was reasonable). The agency’s conclusion that evidentiary hearings are unnecessary and that Congress, in using the phrase “opportunity for public hearing,” did not mean to mandate evidentiary hearings seems reasonable — and Dominion, to its credit, has conceded the point.

Dominion makes two final attempts to resuscitate Seacoast. First, it asseverates that a refusal to follow Seacoast offends the “law of the circuit” rule. That rule (a branch of the stare decisis doctrine) holds that, “[ojrdinarily, newly constituted panels in a multi-panel circuit should consider themselves bound by prior panel decisions” closely on point. Eulitt v. Me., Dep’t of Educ., 386 F.3d 344, 349 (1st Cir.2004). However, the “law of the circuit” rule, like most rules of general application, is subject to exceptions. One such exception “comes into play when a preexisting panel opinion is undermined by subsequently announced controlling authority, such as a decision of the Supreme Court.” Id. In this instance, the Supreme Court’s decisions in Chevron and Brand X counsel against a mechanical application of Seacoast.

Second, Dominion exhorts us to find that Seacoast’s holding is actually an interpretation of the APA, not the CWA (and, therefore, the EPA’s regulation is also an interpretation of the APA, not entitled to Chevron deference). See, e.g., Metro. Stevedore Co. v. Rambo, 521 U.S. 121, 137 n. 9, 117 S.Ct. 1953, 138 L.Ed.2d 327 (1997) (noting that Chevron deference is inappropriate vis-á-vis an agency interpretation of the APA’s burden-of-proof provision). Such a reading of Seacoast is plainly incorrect. While the Seacoast court relied on a presumption borrowed from the APA, the court’s holding is an interpretation of the CWA and, specifically, of the term “public hearing” contained in sections 402(a) and 316(a). The EPA’s regulations are also derived from the CWA. See 40 C.F.R. § 122.1(a) (explaining that 40 C.F.R. § 124 implements sections of the CWA). Because those changes implicate the statute that the EPA administers (i.e., the CWA), Chevron deference is appropriate. See Chevron, 467 U.S. at 842-43, 104 S.Ct. 2778.

IV. CONCLUSION

We summarize succinctly. Although we in no way disparage the soundness of Seacoast’s reasoning, the Chevron and Brand X opinions and the interposition of a new and reasonable agency interpretation of the disputed statutory language have changed the picture. Because we, like the Seacoast court, cannot discern a clear and unambiguous congressional intent behind the words “public hearing” in the CWA and because the EPA’s inter*19pretation of that term constitutes a reasonable construction of the statute, deference is due. It follows inexorably that no non-discretionary duty to grant Dominion an evidentiary hearing on its permit application exists. Consequently, the jurisdictional requirements of section 505(a)(2) have not been satisfied.

We need go no further.3 For the reasons elucidated above, we conclude that the district court did not err in dismissing Dominion’s action.

Affirmed.

*471Mr. Chief Justice Hughes

delivered the opinion of the Court.

These are fifty suits, consolidated for the purpose off trial, to restrain the enforcement of an order of the Secretary of Agriculture, fixing the maximum rates to be charged by market agencies for buying and selling livestock at the Kansas City Stock Yards. Packers and Stockyards Act, 1921, 42 Stat. 159, 7 U. S. C. 181-229.

*472The proceeding was instituted by an order of the Secretary of Agriculture in April, 1930, directing an inquiry into the reasonableness of existing rates. Testimony was taken and an order prescribing- rates followed in May, 1932. An application for rehearing, in view of changed economic conditions, was granted in July, 1932. After the taking of voluminous testimony, which was concluded in November, 1932, the order in question was made on June 14, 1933. Rehearing was refused on July 6, 1933.

Plaintiffs then brought these suits attacking the order, so far as it prescribed maximum charges for selling livestock, as illegal and arbitrary and as depriving plaintiffs of their property without due process of law in violatiqn of the Fifth Amendment of the Constitution. The District Court of three judges entered decrees sustaining the order and dismissing the bills of complaint. 8 F. Supp. 766. Motions for rehearing were denied and, by stipulation, the separate, decrees were set aside and a joint ¿nd final decree was entered to the same effect. Plaintiffs bring this direct appeal. 7 U. S. C. 217; 28 U. S. C. 47.

On- the merits, plaintiffs assert that the ultimate basis for the reduction, in commission rates is the Secretary’s opinion that there are too many market agencies, too many salesmen, and too much competition in the business; that the Secretary has departed entirely from the evidence as to the actual cost of employing salesmen in selling cattle at these yards and has made an allowance for salaries which is based on pure speculation and is wholly inadequate to meet the cost of the service; that he has substituted in place of his accountants’ figures as to actual expenditures, with respect to the item entitled “Business Getting and Maintaining Expense,” a hypothetical allowance greatly less than actual cost; and that the Secretary has thus made findings without evidence and an order, essentially arbitrary, which prescribes *473unreasonable rates. The Government answers that, while the Secretary is not authorized expressly to prescribe or limit the number of firms that may engage in the market agency business, he is under a duty to take cognizance of evidence tending to show that, under present competitive conditions, certain costs actually incurred are unreasonable; that in determining what are just and reasonable rates, he must give consideration to evidence of the excessiveness of costs and if such evidence shows that there are many market agencies not receiving a sufficient volume of business to entitle their costs to be regarded as reasonable, the Secretary must take cognizance of that fact; that it was in this view that the -Secretary made certain findings as to the inadequacy of the present business at the stockyards to support economically all the firms now striving to make a profit; that his findings, supported by evidence, were directly pertinent to the determination of reasonable costs, and so determining the Secretary was authorized to fix the rates prescribed in his order.

Before reaching these questions we meet at the threshold of the controversy plaintiffs’ additional contention that they have not been accorded the hearing which the statute requires. They rightly assert that the granting of that hearing is a prerequisite to the making of a valid order. The statute provides (42 Stat. 159, 166, § 310; 7 U. S. C. 211):

“Sec. 310. Whenever after full hearing upon a complaint made as provided in section 309, or after full hearing under an order for' investigation and hearing made by the Secretary on his own initiative, either in extension of any pending complaint or without - any complaint whatever, the Secretary is of the opinion that any rate, charge, regulation, or practice of a stockyard owner or market agency, for or in connection, with the furnishing of stockyard services, is or will be unjust, unreasonable, or discriminatory, the Secretary—

*474(a) May determine and prescribe what will be the just and reasonable rate or charge, or rates or charges, to be thereafter observed in such case, or the maximum or minimum, or maximum and minimum, to be charged, and what regulation or practice is or will be just; reasonable, and non-discriminatory to be thereafter followed; . .

The allegations as to the failure to give a proper hearing are set forth in Paragraph IV of the bill of complaint, quoted in full .in the margin.1 The allegations in substance are: That separate hearings were not accorded tó the respective respondents (plaintiffs here). That at the *475conclusion of the taking of the testimony before an examiner, a request was made that the examiner prepare a tentative report, which should be subject to oral argument and exceptions, so that a hearing might be had before the Secretary without undue inconvenience to him, but that the.request was denied and no tentative report was exhibited to plaintiffs and no oral argument upon the issues presented by the order of inquiry and the evidence was at any time had before the Secretary. That the Secretary) without warrant of law, delegated to Acting Secretaries the determination of issues *476with respect to the reasonableness of the rates involved. That when the oral arguments were presented after the original.hearing, and after the'rehearing, the Secretary was neither sick, absent, nor otherwise disabled, -but was at his office in the Department of Agriculture and the appointment of - any other person as Acting Secretary was illegal. That the Secretary at the time he signed the order in question had not personally heard or read any of the evidence presented at any hearing in connection with the proceeding and had not heard or considered oral arguments relating thereto or briefs submitted on behalf of the plaintiffs, but that the sole information of the Secretary with respect to the proceeding was derived from consultation with employees in the Department of Agriculture out of the presence of the plaintiffs or any of their representatives.

On motion of the Government, the District Court struck out all the allegations in Paragraph IV of the bill of complaint and the plaintiffs were thus denied opportunity to require an answer to these allegations or' to prove the facts alleged.

Certain facts appear of record. The testimony was taken before an examiner. At its conclusion, counsel for respondents stated “that he would continue to demand that the Secretary hear personally the argument off the evidence in behalf of the individual respondents, or at íeast have some definite course of procedure adopted whereby the examiner, or some one else, should formulate a report on the evidence '.so that the respondents could have the character of hearing and right to present their side of the issues in this case, which they believe the law entitles them to.” The Government does not suggest that this request was granted and plaintiffs say . that it was denied. Oral argument upon the evidence was had before the Acting Secretary of Agriculture. Subsequently, brief was filed on plaintiffs’ be*477half. Thereafter, reciting “careful consideration of .the entire record in this proceeding,” findings of fact and conclusions, and an order prescribing rates, were signed by the Secretary of Agriculture.

First.—The Packers and Stockyards Act makes the provisions of all laws relating to the “suspending or restraining the enforcement”, or the “setting aside” of the orders of the Interstate Commerce Commission applicable to the “jurisdiction, powers and duties of the Secretary” in enforcing the provisions of the Act. § 316; 7 U. S. C. 217. These suits for the review of the administrative action were thus directly authorized and appeal lies under the Urgent Deficiencies Act of October 22, 1913. 38 Stat. 219, 220; 28 U. S. C. 47. Tagg Bros. & Moorhead v. United States, 280 U. S. 420, 443; Acker v. United States, ante, p. 426. All questions touching the regularity and validity of the proceeding before the Secretary are open to review. United States v. Abilene & Southern Ry. Co., 265 U. S. 274, 286-290; Florida v. United States, 282 U. S. 194, 212-215. When the Secretary acts within the authority conferred by the statute, his findings of fact are conclusive. Tagg Bros. & Moorhead v. United States, supra; St. Joseph Stock Yards Co. v. United States, ante, p. 38; Acker v. United States, supra. But, in determining whether in conducting an administrative proceeding of this sort the Secretary has complied with the statutory prerequisites, the recitals of his procedure cannot be regarded as conclusive. Otherwise the statutory conditions could be set at naught by mere assertion. If upon the facts alleged, the “full hearing” required by the statute was not given, plaintiffs were entitled to prove the facts and have the Secretary’s order set aside. Nor is it necessary to go beyond-the terms of the-statute in order to consider the constitutional requirement of due process as to notice and hearing. For the statute itself demands a full hearing and the order is void if such a .hearing was *478denied. Interstate Commerce Comm’n v. Louisville & Nashville R. Co., 227 U. S. 88, 91; United States v. Abilene & Southern Ry. Co., supra; Florida v. United States, supra; United States v. B. & O. R. Co., 293 U. S. 454, 464.

Second.—The outstanding allegation, which thé District Court struck out, is that the Secretary made the rate order without having heard or read any of the evidence, and without having heard the oral arguments or having read or considered the briefs which the plaintiffs submitted. That the only information which the Secretary had. as to the proceeding was what he derived from consultation with employees of the Department.

The other allegations of the stricken paragraph do not go to the root of the matter. Thus, it cannot be said that the failure to hear the respondents separately was' an abuse of discretion. Again, while it would have been good practice to have the examiner prepare a report and submit it to the Secretary and the parties, and to permit exceptions and arguments addressed to the points thus presented,—a practice found to be of great value in proceedings before the Interstate Commerce Commission— we cannot say that , that particular type of procedure was essential to the validity of the hearing. The. statute does not require it and what the statute does require relates to substance and not form.

Nór should the fundamental question be confused with one of mere delegation of authority. The Government urges that the Acting Secretary who heard the oral argument was in'fact the Assistant. Secretary of Agriculture whose duties are prescribed by the Act of February 9, 1889 (5 U. S. C. 517), providing for his appointment and authorizing him to perform such duties in the conduct of the business of the Department of Agriculture as may be assigned to him by the Secretary. If 'the Secretary had assigned to the Assistant Secretary the duty of holding the hearing, and the Assistant Secretary accordingly *479had received the evidence taken by the examiner, had heard argument thereon and had then found the essential facts and made the order upon his findings, we should have had simply the question of delegation. But while the Assistant Secretary heard argument he did not make the decision. The Secretary who, according to the allegation. had neither heard nor read evidence or argument, undertook to make the findings and fix the rates. The Assistant Secretary, who had heard, assumed no responsibility for the findings or order, and the Secretary, who had not heard, did assume that responsibility.

We may likewise put aside the contention as to the circumstances in which an Acting Secretary may take the place of his chief. In the course of administrative routine, the disposition of official matters by an Acting. Secretary is frequently necessary and the integrity of administration demands that credit be given to his action in that capacity. We have no such question here. The Acting Secretary did not assume to make the order.

Third.—What is the essential quality of the proceeding under review, and what is the nature of the hearing which the statute prescribes?

The proceeding is not one of ordinary administration, conformable to the standards governing duties of a purely executive character.' It is a proceeding looking to legislative action in the fixing of rates of market agencies. And, while the order is legislative and gives to the proceeding its distinctive character (Louisville & Nashville R. Co. v. Garrett, 231 U. S. 298, 307), it is a proceeding which by virtue of the authority conferred has special attributes. The Secretary, as the agent of Congress in making the rates, must make them in accordance with the standards and under the limitations which Congress has prescribed. Congress has required the Secretary to determine, as a condition of his action, that the existing rates are or will be “unjust, unreasonable, or discrimina *480tory.” If and when he so finds, he may “determine and prescribe” what shall be the just and reasonable rate, or the maximum or minimum rate, thereafter to be charged. That duty is widely different from ordinary .executive action. It is a duty which carries with it fundamental procedural requirements. There must be a full hearing. There must be evidence adequate to support pertinent and necessary findings of fact. Nothing can be treated as evidence which is not introduced as such. United States v. Abilene & Southern Ry. Co., supra. Facts and circumstances which ought to. be considered must not be excluded. Facts and circumstances must not be considered which should not legally influence the conclusion. Findings based on the evidence must embrace the basic, facts which are needed to sustain the order. Interstate Commerce Comm’n v. Louisville & Nashville R. Co., supra; Chicago Junction Case, 264 U. S. 258, 263; Unite-States v. Abilene & Southern Ry. Co., supra; Florida v. United States, supra; United States v. B. & O. R. Co., supra.

A proceeding of this sort requiring the taking and weighing of evidence, determinations of fact based upon the consideration of the evidence, and the making of an order supported by such findings, has a quality resembling that of a judicial proceeding. Hence it is frequently described as a proceeding of a quasi-judicial character. The requirement of a “full hearing” has obvious reference to the tradition of judicial proceedings in which evidence is received and weighed by the trier of the facts. The “hearing” is designed to afford the safeguard that the one who decides shall be bound in good conscience to consider the evidence, to be guided by that alone, and to reach his conclusion uninfluenced by extraneous considerations which in other fields might have play in determining purely executive action. The “hearing” is the hearing of evidence and argument. If the one who de*481termines the facts'which underlie the order has not considered'evidence or argument, it is manifest that the hearing has'not been given.

There is thus no basis for the contention that the authority conferred by § 310 of the Packers and Stockyards Act is given to the Department of Agriculture, as a department in the administrative sense, so that One official may examine evidence, and another official who has not considered the evidence may make the findings and order. In such a view, it would be possible, for example, for one official to hear the evidence and argument and arrive at certain conclusions of fact, and another official who had not heard or ^considered either evidence or argument to overrule those conclusions and for reasons of policy to announce entirely different ones; It is no answer to say that the question for the court is whether the evidence supports the findings and the findings support the order. For the weight ascribed by the law to the findings—their coneíusiveness when made within the sphere of the authority conferred—rests upon the assumption that the officer who makes .the findings has addressed himself to the evidence and upon that evidence has conscientiously reached the. Conclusions which he deems it to justify. That duty cannot be performed by one who has not considered evidence or argument. It is not an impersonal obligation. It is a duty akin to that of a judge. The one who decides must hear.

This necessary rule does not preclude practicable administrative procedure in' obtaining the aid of assistants in the department. Assistants may prosecute inquiries. Evidence may be taken by an examiner. Evidence thus taken may be sifted and analyzed by competent subordinates. Argument may be oral or written. The requirements are not technical. But there must be a hearing in a substantial sense. And to give the substance of a''hearing, which is for the purpose of making deter*482minations upon evidence, the officer who makes the determinations must consider and appraise the evidence which justifies them. That duty undoubtedly may be an onerous one, but the performance of it in a substantial manner is inseparable from the exercise of the important authority conferred.

The Government presses upon our attention the case of Local Government Board v. Arlidge [1915] A. C. 120, reversing King v. Local Government Board [1914] 1 K. B. 160. That ease has provoked much discussion, but we do not think it necessary to review it, as it relates to a different sort of administrative action and is not deemed to be pertinent to a proceeding under the statute before us and to the hearing which is required by the- principles established by our decisions.

Our conclusion is that the District Court erred in striking out the allegations of Paragraph IV of the bill of complaint with respect to the Secretary’s action. The defendants should be required to answer these allegations and the question whether plaintiffs had a proper hearing should be determined.

The decree is reversed and the cause is remanded for further proceedings in conformity, with this opinion.

Reversed.

MEMORANDUM OPINION

JOHN M. FACCIOLA, United States Magistrate Judge.

This matter was assigned to me for all purposes. Before me is the remaining issue in the Petition of the Federal Trade Commission for an Order Enforcing a Subpoena Duces Tecum [# 1], I resolved the privilege issues presented in that petition and subsequent status reports in my recent Memorandum Opinion [# 69]. Federal Trade Commission v. Boehringer Ingelheim Pharmaceuticals, Inc., 286 F.R.D. 101 (D.D.C.2012). I will now turn to the FTC’s argument that Boehringer Ingelheim Pharmaceuticals, Inc. (“BIPI”) did not conduct an adequate search of its electronically stored information because it refused to search back-up tapes in accordance with the subpoena’s demands.

I. Background

BIPI first filed the executed settlement agreements from the Barr-BIPI litigation 1 with the Department of Justice and *173the Federal Trade Commission in August of 2008. Response of Boehringer Ingelheim Pharmaceuticals, Inc. to the Order to Show Cause [# 34] at 5. Five months later, on February 9, 2009, the FTC served BIPI with the subpoena at issue in this case. Id. BIPI responded to the subpoena by initiating a custodian-directed search, “whereby the inside legal department and outside counsel [were directed to] review the subpoena, identify potentially relevant custodians, ask them about their files, gather potentially responsive files both in electronic and hard copy as appropriate, and review the fruits of the search.” Id. BIPI also “instituted a document preservation notice for persons who were deemed likely to have any responsive documents,” which included placing responsive e-mails in a “hold file” to be “retained indefinitely until the legal hold is lifted.” Id. at 5-6. BIPI identified “over 66 employees” who received the document preservation notice. Id. at 7.

The e-mail system used by BIPI “automatically deleted emails from its employees’ inboxes 90 days after the email was sent or received,” and the FTC argues that this automatic deletion feature was not turned off once the subpoena was served. Reply of the Federal Trade Commission In Further Support of Status Memorandum Advising the Court of New Developments [# 33] at 19. The FTC also complains that some relevant e-mails were inappropriately deleted manually or otherwise lost. Id. at 20. As a whole, argues the FTC, BIPI’s efforts to retain documents through manual archiving of relevant e-mails was not sufficient to prevent all relevant e-mails from being deleted under the 90-day automatic deletion program. Id. Consequently, the FTC requests a search of the back-up tapes “due to the document preservation obligations in this investigation and other litigations.” Id.

Originally, the FTC requested that BIPI search “all of Boehringer’s Electronically Stored Information,” including backup tapes and servers dating back to 2003. See [# 1] at 8-12. BIPI, however, maintains that the “disaster recovery backup tapes ... do not separate [ ] working documents such as spreadsheets, documents, PowerPoints, and other types of materials ... [n]or are' they easily segregable by author or custodian.” [# 34] at 20-21. As such, BIPI estimated that a search of all the backup tapes from January 2003 to October 2010 would cost over $25 million dollars. Id. at 21. This estimate did not include the cost of searching hard drives, which also fell under the FTC’s request that BIPI search “all” databases and archives. Id. at 19-20. During oral argument, however, the FTC conceded that it is “willing to forgo the F & G drive at this point, in favor of the backup tapes.” See Transcript of Status Hearing [# 59] at 70. The FTC also noted that the relevant period for which backup tapes must be searched is February through August, 2008, [#59] at 70, and that a search of four tapes would be sufficient, rather than the 24 originally subpoenaed, id. at 52.

Despite the concessions at oral argument, the FTC retains its position that BIPI did not conduct an adequate search of its records, in that it declined to search any server back-up tapes for responsive documents. See Status Report of the Federal Trade Commission [# 41] at 12-13. BIPI, on the other hand, contends that it has done a full and thorough search and that the FTC’s request for additional electronic searches remains “unnecessary and unduly burdensome.” Response of Boehringer Ingelheim Pharmaceuticals, Inc. to *174the Federal Trade Commission’s Status Report [# 44] at 13.

Fueling this disagreement is a debate among the parties regarding the standard of review for the FTC’s request. The FTC asserts that its request for a search of the backup tapes should be analyzed under the standards of FTC v. Texaco, Inc., 555 F.2d 862 (D.C.Cir.1977). [# 41] at 13. BIPI, on the other hand, points to the “good cause” standard set forth in Federal Rule of Civil Procedure 26(b)(2)(B). [# 44] at 13. This opinion, therefore, must resolve two distinct issues: 1) what law governs requests submitted via administrative subpoena to search information stored on backup tapes; and 2) whether BIPI should be required to conduct a search of the backup tapes, and, if so, under what terms.

II. Legal Standard

Under Federal Rule of Civil Procedure 26(b)(2)(B), “[a] party need not provide discovery of electronically stored information from sources that the party identifies as not reasonably accessible because of undue burden or cost.” Fed. R.Civ.P. 26(b)(2)(B). If the producing party can make such a showing, the court may “nonetheless order discovery from such sources if the requesting party shows good cause.” Fed.R.Civ.P. 26(b)(2)(B). It follows, therefore, that the court will not consider a requesting party’s “good cause” unless the producing party has first met her burden of showing “undue burden or cost.”

In the administrative subpoena context, however, a much stronger showing of “undue burden” is required. See Texaco, 555 F.2d at 882. When evaluating an administrative subpoena enforcement petition, the court should enforce the subpoena “if the inquiry is within the authority of the agency, the demand is not too indefinite and the information sought is reasonably relevant.” Id. at 872 (citing United States v. Morton Salt Co., 338 U.S. 632, 652, 70 S.Ct. 357, 94 L.Ed. 401 (1950)). See also Linde Thomson Langworthy Kohn & Van Dyke, P.C. v. Resolution Trust Corp., 5 F.3d 1508, 1517 (D.C.Cir.1993) (“The burden of proving undue hardship ‘is not easily met where ... the agency inquiry is pursuant to a lawful purpose and the requested documents are relevant to that purpose.’ ”).2

To that end, to reject a petition to enforce an administrative subpoena, this Circuit requires a showing that compliance with the subpoena “threatens to unduly disrupt or seriously hinder normal operations of a business.” Texaco, 555 F.2d at 882. “The burden of showing that the request is unreasonable is on the subpoenaed party.” Id. This does not mean the Court’s hands are tied to the exact terms of the subpoena request; indeed, “in formulating protective conditions for administrative subpoenas, courts may resort analogously to techniques conventional to judicial subpoenas.” Sec. & Exch. Comm’n v. Arthur Young & Co., 584 F.2d 1018, 1033 (D.C.Cir.1978) (citing the- Federal Rules of Civil Procedure as one such technique).

III. Analysis

There is no doubt that the breadth of the search requested in the FTC’s original subpoena would have consumed much of BIPI’s time and money. Many of the *175status updates and other submissions to the Court on this issue addressed whether the search, as requested, constituted an undue burden on BIPI. Although both sides raised interesting arguments in this regard, the request as it stands today is on a different scale. Developments between the parties, both on their own and before me during the last status conference, indicate that the scope of the search requested by the FTC has been narrowed significantly, and as a result, it appears that the request is, in its modified form, not unduly burdensome for BIPI. See Texaco, 555 F.2d at 882-83.

I am not convinced, having reviewed the status reports of both the FTC and BIPI, that such a limited search would be the kind of burden upon BIPI described in the Texaco case — “threaten[ing] to unduly disrupt or seriously hinder normal operations of a business.” Texaco, 555 F.2d at 882. BIPI bears the burden of establishing such a disruption and it has not demonstrated to the Court, either through filings or during the November 2011 status conference, that complying with this request, as modified, would meet that burden. Instead, “some burden on the subpoenaed party is to be expected.” Federal Trade Commission v. Church & Dwight Co., Inc., 747 F.Supp.2d 3, 8 (D.D.C.2010), aff'd 665 F.3d 1312 (D.C.Cir.2011). BIPI is a large pharmaceutical company, and, although it does not have unlimited resources, it certainly has the ability to conduct the limited search requested here.

More to the point, the burden or lack thereof in doing the search is a function of how efficiently it is conducted. Obviously, to the extent that documents found on the backup tapes are duplicative or near-duplicative of documents already disclosed or deemed privileged, production is unnecessary and unwarranted. The parties should meet and confer to determine the appropriate method of searching the relevant backup tapes to render the process as efficient as possible. Additionally, if they deem it appropriate, I will ask the mediator who assisted them previously to meet with them again to guide their discussions as to how to conduct the search. If the parties still cannot agree, they will have to submit their disagreement to me for resolution.

Additionally, any documents produced by this search and claimed to be privileged will be subject to the same principles and holdings laid out in my recent opinion in this case. See Memorandum Opinion [# 69]. Thus, to the extent that the documents produced in the backup tape search fall under the work product or attorney-client privileges, as I have interpreted them in that opinion, they would be protected from disclosure. Searching for them again would result in a needless expenditure of resources.

Any documents found on the backup tapes that are responsive and not privileged must be turned over immediately. As stated previously, however, if a document contains some factual work product and some opinion work product, and the opinion work product can be excised from the rest of the document, BIPI should redact the privileged material and disclose the rest. If, at the end of this process, there remains a dispute as to whether any of these documents may be privileged, they may be submitted to me for in camera review.

An Order accompanies this Memorandum Opinion.

Justice Powell

delivered the opinion of the Court.

The issue is whether the Secretary of Health and Human Services may rely on published medical-vocational guidelines to determine a claimant’s right to Social Security disability benefits.

I

The Social Security Act defines “disability” in terms of the effect a physical or mental impairment has on a person’s abil*460ity to function in the workplace. It provides disability benefits only to persons who are unable “to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment.” 81 Stat. 868, as amended, 42 U. S. C. § 423(d)(1)(A). And it specifies that a person must “not only [be] unable to do his previous work but [must be unable], considering his age, education, and work experience, [to] engage in any other kind of substantial gainful work which exists in the national economy, regardless of whether such work exists in the immediate area in which he lives, or whether a specific job vacancy exists for him, or whether he would be hired if he applied for work.” 42 U. S. C. § 423(d)(2)(A).

In 1978, the Secretary of Health and Human Services promulgated regulations implementing this definition. See 43 Fed. Reg. 55349 (1978) (codified, as amended, at 20 CFR pt. 404, subpt. P (1982)). The regulations recognize that certain impairments are so severe that they prevent a person from pursuing any gainful work. See 20 CFR § 404.1520(d) (1982) (referring to impairments listed at 20 CFR pt. 404, subpt. P, app. 1). A claimant who establishes that he suffers from one of these impairments will be considered disabled without further inquiry. Ibid. If a claimant suffers from a less severe impairment, the Secretary must determine whether the claimant retains the ability to perform either his former work or some less demanding employment. If a claimant can pursue his former occupation, he is not entitled to disability benefits. See §404.1520(e). If he cannot, the Secretary must determine whether the claimant retains the capacity to pursue less demanding work. See §404.1520(f)(1).

■ The regulations divide this last inquiry into two stages. First, the Secretary must assess each claimant’s present job qualifications. The regulations direct the Secretary to consider the factors Congress has identified as relevant: physical ability, age, education, and work experience.1 See 42 *461U. S. C. § 423(d)(2)(A); 20 CFR § 404.1520(f) (1982). Second, she must consider whether jobs exist in the national economy that a person having the claimant’s qualifications could perform. 20 CFR §§ 404.1520(f), 404.1566-404.1569 (1982).

Prior to 1978, the Secretary relied on vocational experts to establish the existence of suitable jobs in the national economy. After a claimant’s limitations and abilities had been determined at a hearing, a vocational expert ordinarily would testify whether work existed that the claimant could perform. Although this testimony often was based on standardized guides, see 43 Fed. Reg. 9286 (1978), vocational experts frequently were criticized for their inconsistent treatment of similarly situated claimants. See Santise v. Schweiker, 676 F. 2d 925, 930 (CA3 1982); J. Mashaw, C. Goetz, F. Goodman, W. Schwartz, P. Verkuil, & M. Carrow, Social Security Hearings and Appeals 78-79 (1978). To improve both the uniformity and efficiency2 of this determination, the Secretary promulgated medical-vocational guidelines as part of the 1978 regulations. See 20 CFR pt. 404, subpt. P, app. 2 (1982).

These guidelines relieve the Secretary of the need to rely on vocational experts by establishing through rulemaking the types and numbers of jobs that exist in the national economy. They consist of a matrix of the four factors identified by Con*462gress — physical ability, age, education, and work experience3 — and set forth rules that identify whether jobs requiring specific combinations of these factors exist in significant numbers in the national economy.4 Where a claimant’s qualifications correspond to the job requirements identified by a rule,5 the guidelines direct a conclusion as to whether work exists that the claimant could perform. If such work exists, the claimant is not considered disabled.

t — I HH

In 1979, Carmen Campbell applied for disability benefits because a back condition and hypertension prevented her from continuing her work as a hotel maid. After her application was denied, she requested a hearing de novo before an Administrative Law Judge.6 He determined that her back *463problem was not severe enough to find her disabled without further inquiry, and accordingly considered whether she retained the ability to perform either her past work or some less strenuous job. App. to Pet. for Cert. 28a. He concluded that even though Campbell’s back condition prevented her from returning to her work as a maid, she retained the physical capacity to do light work. Ibid. In accordance with the regulations, he found that Campbell was 52 years old, that her previous employment consisted of unskilled jobs, and that she had a limited education. Id., at 28a-29a. He noted that Campbell, who had been born in Panama, experienced difficulty in speaking and writing English. She was able, however, to understand and read English fairly well. App. 42. Relying on the medical-vocational guidelines, the Administrative Law Judge found that a significant number of jobs existed that a person of Campbell’s qualifications could perform. Accordingly, he concluded that she was not disabled.7 App. to Pet. for Cert. 29a.

This determination was upheld by both the Social Security Appeals Council, id., at 16a, and the District Court for the Eastern District of New York, id., at 15a. The Court of Appeals for the Second Circuit reversed. Campbell v. Secretary of Dept. of Health and Human Services, 665 F. 2d 48 (1981). It accepted the Administrative Law Judge’s determination that Campbell retained the ability to do light work. And it did not suggest that he had classified Campbell’s age, *464education, or work experience incorrectly. The court noted, however, that it

“has consistently required that ‘the Secretary identify specific alternative occupations available in the national economy that would be suitable for the claimant’ and that ‘these jobs be supported by “a job description clarifying the nature of the job, [and] demonstrating that the job does not require” exertion or skills not possessed by the claimant.’” Id., at 53 (quoting Decker v. Harris, 647 F. 2d 291, 298 (CA2 1981)).

The court found that the medical-vocational guidelines did not provide the specific evidence that it previously had required. It explained that in the absence of such a showing, “the claimant is deprived of any real chance to present evidence showing that she cannot in fact perform the types of jobs that are administratively noticed by the guidelines.” 665 F. 2d, at 53. The court concluded that because the Secretary had failed to introduce evidence that specific alternative jobs existed, the determination that Campbell was not disabled was not supported by substantial evidence. Id., at 54.

We granted certiorari to resolve a conflict among the Courts of Appeals.8 Schweiker v. Campbell, 457 U. S. 1131 (1982). We now reverse.

*465III

The Secretary argues that the Court of Appeals’ holding effectively prevents the use of the medical-vocational guidelines. By requiring her to identify specific alternative jobs in every disability hearing, the court has rendered the guidelines useless. An examination of both the language of the Social Security Act and its legislative history clearly demonstrates that the Secretary may proceed by regulation to determine whether substantial gainful work exists in the national economy. Campbell argues in response that the Secretary has misperceived the Court of Appeals’ holding. Campbell reads the decision as requiring only that the Secretary give disability claimants concrete examples of the kinds of factual determinations that the administrative law judge will be making. This requirement does not defeat the guidelines’ purpose; it ensures that they will be applied only where appropriate. Accordingly, respondent argues that we need not address the guidelines’ validity.

A

The Court of Appeals held that “[i]n failing to show suitable available alternative jobs for Ms. Campbell, the Secretary’s finding of ‘not disabled’ is not supported by substantial evidence.” 665 F. 2d, at 54. It thus rejected the proposition that “the guidelines provide adequate evidence of a claimant’s ability to perform a specific alternative occupation,” id., at 53, and remanded for the Secretary to put into evidence “particular types of jobs suitable to the capabilities of Ms. Campbell,” id., at 54. The court’s requirement that additional evidence be introduced on this issue prevents the Secretary from putting the guidelines to their intended use and implicitly calls their validity into question.9 Accord*466ingly, we think the decision below requires us to consider whether the Secretary may rely on medical-vocational guidelines in appropriate cases.

The Social Security Act directs the Secretary to “adopt reasonable and proper rules and regulations to regulate and provide for the nature and extent of the proofs and evidence and the method of taking and furnishing the same” in disability cases. 42 U. S. C. § 405(a). As we previously have recognized, Congress has “conferred on the Secretary exceptionally broad authority to prescribe standards for applying certain sections of the [Social Security] Act.” Schweiker v. Gray Panthers, 453 U. S. 34, 43 (1981); see Batterton v. Francis, 432 U. S. 416, 425 (1977). Where, as here, the statute expressly entrusts the Secretary with the responsibility for implementing a provision by regulation,10 our review is limited to determining whether the regulations promulgated exeeded the Secretary's statutory authority and whether they are arbitrary and capricious. Herweg v. Ray, 455 U. S. 265, 275 (1982); Schweiker v. Gray Panthers, supra, at 44.

*467We do not think that the Secretary’s reliance on medical-vocational guidelines is inconsistent with the Social Security Act. It is true that the statutory scheme contemplates that disability hearings will be individualized determinations based on evidence adduced at a hearing. See 42 U. S. C. § 423(d)(2)(A) (specifying consideration of each individual’s condition); 42 U. S. C. § 405(b) (1976 ed., Supp. V) (disability determination to be based on evidence adduced at hearing). But this does not bar the Secretary from relying on rulemaking to resolve certain classes of issues. The Court has recognized that even where an agency’s enabling statute expressly requires it to hold a hearing, the agency may rely on its rulemaking authority to determine issues that do not require case-by-case consideration. See FPC v. Texaco Inc., 377 U. S. 33, 41-44 (1964); United States v. Storer Broadcasting Co., 351 U. S. 192, 205 (1956). A contrary holding would require the agency continually to relitigate issues that may be established fairly and efficiently in a single rulemaking proceeding. See FPC v. Texaco Inc., supra, at 44.

The Secretary’s decision to rely on medical-vocational guidelines is consistent with Texaco and Storer. As noted above, in determining whether a claimant can perform less strenuous work, the Secretary must make two determinations. She must assess each claimant’s individual abilities and then determine whether jobs exist that a person having the claimant’s qualifications could perform. The first inquiry involves a determination of historic facts, and the regulations properly require the Secretary to make these findings on the basis of evidence adduced at a hearing. We note that the regulations afford claimants ample opportunity both to present evidence relating to their own abilities and to offer evidence that the guidelines do not apply to them.11 The sec*468ond inquiry requires the Secretary to determine an issue that is not unique to each claimant — the types and numbers of jobs that exist in the national economy. This type of general factual issue may be resolved as fairly through rulemaking as by introducing the testimony of vocational experts at each disability hearing. See American Airlines, Inc. v. CAB, 123 U. S. App. D. C. 310, 319, 359 F. 2d 624, 633 (1966) (en banc).

As the Secretary has argued, the use of published guidelines brings with it a uniformity that previously had been perceived as lacking. To require the Secretary to relitigate the existence of jobs in the national economy at each hearing would hinder needlessly an already overburdened agency. We conclude that the Secretary’s use of medical-vocational guidelines does not conflict with the statute, nor can we say on the record before us that they are arbitrary and capricious.

B

We now consider Campbell’s argument that the Court of Appeals properly required the Secretary to specify alternative available jobs. Campbell contends that such a showing informs claimants of the type of issues to be established at the hearing and is required by both the Secretary’s regulation, 20 CFR §404.944 (1982), and the Due Process Clause.

By referring to notice and an opportunity to respond, see 665 F. 2d, at 53-54, the decision below invites the interpretation given it by respondent. But we do not think that the decision fairly can be said to present the issues she raises.12 *469The Court of Appeals did not find that the Secretary failed to give sufficient notice in violation of the Due Process Clause or any statutory provision designed to implement it. See 42 U. S. C. §405(b) (1976 ed., Supp. V) (requiring that disability claimants be given “reasonable notice and [an] opportunity for a hearing”). Nor did it find that the Secretary violated any duty imposed by regulation. See 20 CFR § 404.944 (1982) (requiring the administrative law judge to “loo[k] fully into the issues”). Rather the court’s reference to notice and an opportunity to respond appears to be based on a principle of administrative law — that when an agency takes official or administrative notice of facts, a litigant must be given an adequate opportunity to respond.13 See 5 U. S. C. § 556(e); McDaniel v. Celebrezze, 331 F. 2d 426 (CA4 1964).

*470This principle is inapplicable, however, when the agency has promulgated valid regulations. Its purpose is to provide a procedural safeguard: to ensure the accuracy of the facts of which an agency takes notice. But when the accuracy of those facts already has been tested fairly during rulemaking, the rulemaking proceeding itself provides sufficient procedural protection.14 See, e. g., Rivers v. Schweiker, 684 F. 2d 1144, 1156 (CA5 1982); Broz v. Schweiker, 677 F. 2d 1351, 1362 (CA11 1982); Torres v. Secretary of Health and Human Services, 677 F. 2d 167, 169 (CA1 1982).

> HH

The Court of Appeals’ decision would require the Secretary to introduce evidence of specific available jobs that respondent could perform. It would limit severely her ability to rely on the medical-vocational guidelines. We think the Secretary reasonably could choose to rely on these guidelines in appropriate cases rather than on the testimony of a vocational expert in each case. Accordingly, the judgment of the Court of Appeals is

Reversed.

Justice Brennan,

concurring.

I join the Court’s opinion. It merits comment, however, that the hearing respondent received, see ante, at 462-463, if it is in any way indicative of standard practice, reflects *471poorly on the Administrative Law Judge’s adherence to what Chief Judge Godbold has called his “duty of inquiry”:

“[T]here is a ‘basic obligation’ on the ALJ in these nonadversarial proceedings to develop a full and fair record, which obligation rises to a ‘ “special duty ... to scrupulously and conscientiously explore for all the relevant facts’” where an unrepresented claimant has not waived counsel. This duty of inquiry on the ALJ would include, in a case decided under the grids, a duty to inquire into possible nonexertional impairments and into exertional limitations that prevent a full range of work.” Broz v. Schweiker, 677 F. 2d 1351, 1364 (CA11 1982).1

In her brief to this Court, the Secretary acknowledges that the Social Security regulations embody this duty and relies upon it in answering respondent’s due process contentions. Brief for Petitioner 42 (citing Broz v. Schweiker, supra)] see 20 CFR § 404.944 (1982); ante, at 468, and n. 12. The Administrative Law Judge’s “duty to inquire” takes on special urgency where, as here, the claimant has little education and limited fluency in English, and, given that the claimant already has a right to a hearing, the additional cost of pursuing relevant issues at the hearing is minimal.

*472In order to find that respondent was not disabled, the Secretary had to determine that she had the physical capacity to do “light work,” compare 20 CFR pt. 404, subpt. P, app. 2, §201.10 (1982), with id., §202.10, a determination that required a finding that she was capable of frequent lifting or carrying of objects weighing up to 10 pounds and sometimes lifting up to 20 pounds, 20 CFR §404.1567(b) (1982). The hearing record included one disinterested doctor’s report of a medical examination of respondent that concluded with the unexplained statement “Patient may return to light-duty work,” App. 11, and a subsequent report by a second disinterested doctor stating that respondent could lift and carry only “up to 10 pounds,” id., at 32. In finding that respondent could perform “light work,” the Administrative Law Judge rejected the second doctor’s report as “without basis.” App. to Pet. for Cert. 23a-25a. Yet he failed entirely to adduce evidence relevant to this issue at respondent’s hearing. At several points during the hearing, respondent stated that she could not lift things, but the Administrative Law Judge did not question her on the subject at all,2 nor did he make any inquiry whether by “light-duty work” the first doctor meant the same thing as the Secretary’s term “light work.”

The Administrative Law Judge further failed to inquire whether factors besides strength, age, or education, combined with her other impairments, rendered respondent disabled. See 20 CFR pt. 404, supra, § 200.00(e)(2); ante, at 462, n. 5. Apparently such factors could have been dispositive of *473the case before us: The Secretary has since determined that respondent is in fact disabled, see ante, at 463, n. 7, based on consideration of severe emotional complications not explored at all by the Administrative Law Judge in the hearing that led to her petition for review in this case.3

This issue was not presented to the Court of Appeals, nor passed upon by it. See ante, at 468-469, n. 12. In terms of ensuring fair and accurate determinations of disability claims, the obligation that the Court of Appeals would have placed on administrative law judges was a poor substitute for good-faith performance of the “duty of inquiry” they already have. The federal courts have been successful in enforcing this duty in the past, see n. 1, supra, and I respectfully suggest that the Secretary insist upon its faithful performance in future cases.

Justice Marshall,

concurring in part and dissenting in part.

While I agree that the Secretary’s medical-vocational guidelines are valid, I believe that this case presents the additional question whether the Administrative Law Judge fulfilled his obligation to “loo[k] fully into the issues.” 20 CFR §404.944 (1982). See Richardson v. Perales, 402 U. S. 389, 410 (1971) (at the hearing the administrative law judge is required to “ac[t] as an examiner charged with developing the facts”). I would therefore remand this case for further proceedings.

I do not agree with the Court, ante, at 468-469, that the decision below does not question the adequacy of the Administrative Law Judge’s inquiry at the hearing. Although the Court of Appeals’ opinion is not entirely clear, the court ap*474pears to have concluded that Campbell was not given an adequate opportunity to demonstrate that she was unable to perform “light work.” The court explained as follows:

“ ‘The key consideration in the administrative proceeding must be that the claimant be given adequate opportunity to challenge the suitability ... of the jobs noticed. . . .’ [0]ur major concern is that the claimant be given adequate notice of the nature and demands of the types of jobs allegedly available. Absent sufficient notice, the claimant is deprived of any real chance to present evidence showing that she cannot in fact perform the types of jobs that are administratively noticed by the guidelines. This is particularly true in Ms. Campbell’s case where the ALJ gave no indication of any specific ‘light work’ jobs that she was capable of performing . . . .” Campbell v. Secretary of Dept. of Health and Human Services, 665 F. 2d 48, 53-54 (CA2 1981), quoting Decker v. Harris, 647 F. 2d 291, 298 (CA2 1981).1

The Court of Appeals remanded the case for further administrative proceedings at which Campbell would be given “a listing of particular types of jobs suitable to the capabilities of Ms. Campbell.” 665 F. 2d, at 54.

The Court of Appeals’ concern was amply justified in light of the hearing that was conducted in this case. The central *475issue at respondent’s hearing was whether she was capable of performing “light work.”2 If Campbell had shown that she was unable to perform “light work,” she would have been entitled to disability benefits under the Secretary’s guidelines. Although Campbell was afforded a hearing to determine whether she was disabled, she was never apprised of this central issue either in advance of or during the hearing. She was not represented by counsel, and the Administrative Law Judge who conducted the hearing never explained to her what “light work” entailed. Moreover, although the judge inquired at length into respondent’s medical problems, he conducted little inquiry into the effect of her medical problems on her capacity to perform work. Yet reasonably complete questioning concerning the claimant’s ability to function in her daily activity was essential to resolving this question in a fair manner.3

*476The above-quoted portions of the Court of Appeals’ decision demonstrate to my satisfaction that the question whether respondent received an adequate hearing is fairly raised by the decision below. It would have been well within the Court of Appeals’ authority under 42 U. S. C. § 405(g) (1976 ed., Supp. V) to order a new hearing if the court concluded that the Administrative Law Judge failed to conduct an adequate inquiry.4 That appears to be just what the court did when it remanded the case. The court required the judge to fulfill his obligation to elicit testimony concerning respondent’s capacity to perform “light work” by giving her a few examples of specific types of “light work” and allowing her to explain why she is unable to perform such work.