Full opinion text
ROBB, Circuit Judge: These consolidated cases present challenges to regulations and actions of the Environmental Protection Agency and its Administrator pursuant to the Federal Water Pollution Control Act Amendments of 1972 (FWPCA), 33 U.S.C. § 1251 et seq. (Supp. IV). In No. 74-1967 American Paper Institute (API), joined by eight companies engaged in the production of pulp, paper and paperboard, challenged the EPA regulations by way of a suit in the United States District Court for the District of Columbia. The court held that under Section 509(b)(1) of the FWPCA jurisdiction to review these regulations was in a United States Court of Appeals and not in the District Court; accordingly the court granted EPA’s motion to dismiss for lack of subject matter jurisdiction. American Paper Institute v. Train, 381 F.Supp. 553 (D.D.C.1974). The plaintiffs appeal. The appeal from this dismissal has been consolidated here with petitions for review filed by API and the eight paper manufacturing companies. For convenience we shall refer to the appellants and the petitioners collectively as API. The petitions for review challenge both the regulations and the implementation of the FWPCA by EPA. These regulations were promulgated May 29, 1974 and establish effluent limitations guidelines and new source performanee standards for five subcategories of the pulp, paper and paperboard industries. We affirm the District Court’s dismissal, uphold as valid the Agency’s promulgated regulations and dismiss the various petitions for review. I. THE STATUTE The FWPCA establishes a comprehensive scheme for federal regulation of water pollution. The ultimate objective of the Act is to eliminate completely the discharge of pollution into navigable waters by 1985. The Act seeks to accomplish this by means of phased reductions in the amounts of pollutants which are discharged from municipal and industrial sources. Recently, in a lengthy and detailed opinion by another panel, this court reviewed and interpreted certain provisions of the Act which play a key role in this process. American Frozen Food Institute v. Train, 176 U.S.App.D.C. 105, 539 F.2d 107, No. 74-1464 (1976). Because the present case involves a discussion of these same statutory provisions, we dispense with an elaborate analysis of what is indeed a “complicated and lengthy statute,” AFFI v. Train, supra, 539 F.2d at 115, and simply sketch, in abbreviated fashion, those sections of the Act with which we must deal. Section 301, entitled “Effluent Limitations”, requires all existing point source dischargers of pollution to meet two levels of effluent standards: one level by July 1, 1977, and the other by July 1, 1983. 33 U.S.C. § 1311. The 1977 level requires the application of the “best practicable control technology currently available” for point sources other than publicly owned treatment works. (BPCTCA or “best practicable”) Section 301(b)(1)(A). The 1983 level requires the application of the “best available technology economically achievable” for these same sources. (BATEA or “best available”) Section 301(b)(2)(A). These same provisions of Section 301 also state that the defined levels of technology are to be given more specific meaning in regulations issued by the EPA pursuant to Section 304. Section 304, entitled “Information and Guidelines”, indicates the method by which precise definitions for the two standards are to be achieved. 33 U.S.C. § 1314. Under Section 304(b)(1), which applies to the 1977 BPCTCA standard, the Administrator is to establish guidelines for effluent limitations. These regulations are to (1) identify the degree of effluent reduction attainable through best practicable control technology currently available for classes and categories of point sources, other than publicly owned treatment works, and (2) specify factors to be taken into account in determining the control measures and practices applicable to such point sources. Section 304(b)(1)(A) & (B). Under Section 304(b)(2), which applies to the 1983 BATEA standard, the Administrator is to publish regulations which take into account similar considerations. Thus, the effluent limitations required under Section 301 are to be achieved pursuant to guidelines established by EPA under Section 304. Another section of importance in this case is Section 306. 33 U.S.C. § 1316. Unlike Sections 301 and 304 which pertain to effluent standards required for existing sources, Section 306 governs the standard for new sources of pollution discharge. This section specifies twenty-seven industries for which standards for new sources must be set, including the pulp, paper and paperboard industry. The standard for new sources must reflect the greatest degree of effluent reduction achievable through application of the “best available demonstrated control technology” (BADCT), including where practicable, a standard permitting no discharge of pollutants. Hence, under Sections 301, 304 and 306 of the FWPCA the Administrator is responsible for regulations which define three separate levels of pollution control: (a) the 1977 “best practicable” (BPCTCA) standard for existing sources; (b) the 1983 “best available” (BATEA) standard for existing sources; (c) the “best available demonstrated” (BADCT) standard for new sources. In general, the statute envisions the 1977 standard as a minimum level of control, the 1983 standard as more stringent, and the new source performance standards as the most stringent. Primary enforcement of these standards is to be accomplished under Section 402 of the Act. 33 U.S.C. § 1342. This section establishes a permit system as the basic mechanism for enforcing the effluent limitations established under Section 301. Permits for pollutant discharge may be issued by the Administrator or by a state which has adopted a permit program approved by the Administrator. Section 402(a) and (b). The function of the permit is to define precisely each individual discharger’s obligations under the Act. EPA retains authority to review operation of a state's permit program and may withdraw approval of a program which is not being administered in compliance with this section. Section 402(c) and (d). The final statutory provision that is important here is Section 509. 33 U.S.C. § 1369. This section, entitled “Administrative Procedure and Judicial Review”, establishes that the United States courts of appeal have exclusive jurisdiction to review the Administrator’s actions in promulgating effluent limitations under Section 301. Section 509(b)(1)(E). II. EPA PROCEEDINGS In January 1973 EPA contracted with a private engineering consultant firm, Wapora, Inc., to make an analysis of the pulp and paper industry to aid EPA in developing effluent limitations and new source performance standards. The Wapora study concentrated only on that portion of the industry involved in unbleached pulp and paper (Phase I), and the regulations at issue here are only these Phase I regulations. The Wapora study resulted in a 245-page draft report which was submitted to EPA in June 1973. The draft report stated that as a result of various factors this Phase I category of the paper industry should be subdivided into five subcategories: unbleached kraft, sodium base neutral sulfite semi-chemical, ammonia base neutral sulfite semi-chemical, unbleached kraft-NSSC (cross recovery), and waste paperboard. (App. 41) The report then discussed water use and waste characterization, selection of various pollutants, control and treatment technologies, costs, energy, non-water quality aspects, and implementation requirements. (App. 44-162) This information was then evaluated to make a preliminary determination of the effluent limitations and new source performance standards for each subcategory. (App. 162-180) In July 1973 copies of the contractor’s draft report were circulated and comments solicited from 160 government, state, industry, and private institutions. Twenty-five organizations, including API, responded. Their comments resulted in changes being made in the draft report and in the forthcoming proposed regulations. (App. 1335) On August 6, 1973 EPA published an “Advance Notice of Public Review Procedures” which set out EPA’s general course in developing the regulations for the effluent limitations and new source performance standards. (App. 730) The notice explained the legal authority for the regulations, the general methodology employed in their development, and the means by which EPA would facilitate comment on them. (App. 730-734) On January 15, 1974 the proposed guidelines and standards were published in the Federal Register. (App. 1331) The proposed regulations were supported by the contractor’s draft report in its proposed form — known formally as the Development Document for Proposed Effluent Limitations Guidelines and New Source Performance Standards for the Unbleached Kraft and Semichemical Pulp Segment of the Pulp, Paper and Paperboard Mills Point Source Category. [Draft Development Document] (App. 956-1330) In addition, a second document concerning economic analysis and entitled Economic Analysis of Proposed Effluent Guidelines, Pulp, Paper and Paperboard Industry was made available to the public and circulated along with the Draft Development Document. (App. 735-955) Once again comments were solicited; thirty-seven parties, including API, responded and additional changes were made in the regulations. (App. 2199, 2203) A technical hearing on the regulations was held on April 15, 1974. This hearing was in response to API’s request, after the two comment periods, for an additional opportunity to comment on the regulations. (App. 1935-36) A transcript of this hearing may be found at App. 1937-2185. On May 29, 1974 EPA promulgated final regulations setting forth “final effluent limitations guidelines for existing sources and standards of performance and pretreatment standards for new sources in the pulp, paper, and paperboard category of point sources.” (App. 2199) These are the regulations at issue on this appeal. They are supported by a 340-page final development document which bears substantially the same title as the earlier draft: Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Unbleached Kraft and Semichemical Pulp Segment of the Pulp, Paper, and Paperboard Mills Points Source Category. [Final Development Document] (App. 2210-2565) The promulgated regulations are divided into the five subcategories previously mentioned. See p. 9 supra. In comments preceding the promulgated regulations EPA alluded to the flexibility provision contained within each of the five subcategories. Comment (7) states: Section 304(b)(1)(B) of the Act provides for “guidelines” to implement the uniform national standards of section 301(b)(1)(A). Thus Congress recognized that some flexibility was necessary in order to take into account the complexity of the industrial world with respect to the practicability of pollution control technology. In conformity with the Congressional intent and in recognition of the possible failure of these regulations to account for all factors bearing on the practicability of control technology, it was concluded that some provision was needed to authorize flexibility in the strict application of the limitations contained in the regulation where required by special circumstances applicable to individual dischargers. Accordingly, a provision allowing flexibility in the application of the limitations representing best practicable control technology currently available has been added to each subpart, to account for special circumstances that may not have been adequately accounted for when these regulations were developed. (App. 2203) (Emphasis added.) The flexibility provision incorporated into each of the five subcategories reads as follows: In establishing the limitations set forth in this section, EPA took into account all information it was able to collect, develop and solicit with respect to factors (such as age and size of plant, raw materials, manufacturing processes, products produced, treatment technology available, energy requirements and costs) which can affect the industry subcategorization and effluent levels established. It is, however, possible that data which would affect these limitations have not been available and, as a result, these limitations should be adjusted for certain plants in this industry. An individual discharger or other interested person may submit evidence to the Regional Administrator (or to the State, if the State has the authority to issue NPDES permits) that factors relating to the equipment or facilities involved, the process applied, or other such factors related to such discharger are fundamentally different from the factors considered in the establishment of the guidelines. On the basis of such evidence or other available information, the Regional Administrator (or the State) will make a written finding that such factors are or are not fundamentally different for that facility compared to those specified in the Development Document. If such fundamentally different factors are found to exist, the Regional Administrator or the State shall establish for the discharger effluent limitations in the NPDES permit either more or less stringent than the limitations established herein, to the extent dictated by such fundamentally different factors. Such limitations must be approved by the Administrator of the Environmental Protection Agency. The Administrator may approve or disapprove such limitations, specify other limitations, or initiate proceedings to revise these regulations. (App. 2204-8) (Emphasis added.) These, then, are the final regulations promulgated by EPA and challenged by API in the District Court, and on these petitions for review. The only issue before the District Court was whether it had jurisdiction to review the regulations. The court held that Section 509 of the FWPCA provides for review by a United States Court of Appeals and not by a United States District Court. American Paper Institute v. Train, 381 F.Supp. 553 (D.D.C.1974). Before we turn to the merits of the challenged regulations, three preliminary matters must be addressed. These are the questions of our jurisdiction under Section 509, the Administrator’s implementation of the Act under Sections 301 and 304, and the “range” of effluent limitations for this industry. All three are issues raised by API and recently resolved by this court in American Frozen Food Institute v. Train, 176 U.S.App.D.C. 105, 539 F.2d 107, No. 74-1464 (1976). Accordingly, our discussion will be brief. III. RECENTLY RESOLVED ISSUES A. Jurisdiction API contends that the regulations promulgated by EPA are Section 304 guidelines reviewable by the District Court under the Administrative Procedure Act, 5 U.S.C. § 551 et seq. (1970). EPA argues that the Section 304 guidelines are inextricably intertwined with the Section 301 effluent limitations and that the regulations are therefore effluent limitations guidelines promulgated pursuant to both Sections 301 and 304. Thus, argues EPA, review is lodged exclusively in the courts of appeal under Section 509 which states in pertinent part: (b)(1) Review of the Administrator’s action ******„ (E) in approving or promulgating any effluent limitation or other limitation under section 301, 302, or 306 . may be had by any interested person in the Circuit Court of Appeals of the United States . Because Section 509 makes no mention of judicial review of Section 304 guidelines, Section 509 will not apply and review is not lodged exclusively in this court unless we determine that the regulations published by EPA are effluent limitations guidelines under Sections 301 and 304. In AFFI v. Train, supra, this court analyzed the language and legislative history of the FWPCA in detail and resolved this question in favor of the Agency. We note that the Eighth Circuit takes a contrary view, CPC International, Inc. v. Train, 515 F.2d 1032 (8th Cir. 1975), but that the Second, Third, Fourth, Seventh and Tenth Circuits are in agreement with us. Hooker Chemicals & Plastics Corp. v. Train, 537 F.2d 620 (2d Cir. 1976); American Iron & Steel Institute v. EPA, 526 F.2d 1027 (3rd Cir. 1975); E. I. duPont de Nemours & Co. v. Train, 528 F.2d 1136 (4th Cir. 1975), cert. granted, 425 U.S. 933, 96 S.Ct. 1662, 48 L.Ed.2d 174 (1976) (No. 75-978) (duPont I); American Meat Institute v. EPA, 526 F.2d 442 (7th Cir. 1975); American Petroleum Institute v. EPA, 526 F.2d 1343 (10th Cir. 1975). Accordingly, we reaffirm the view expressed in AFFI v. Train, supra, 539 F.2d at 129-30, that this court has jurisdiction under Section 509 of the FWPCA to review the effluent limitations guidelines which have been promulgated by the Administrator pursuant to Sections 301 and 304 of the Act. B. Implementation The question presented here is whether the effluent limitations guidelines published by EPA pursuant to Sections 301 and 304 reflect a proper implementation of the FWPCA. API contends that EPA should merely publish guidelines to assist the Section 402 permit-granting authorities, which in turn will establish effluent limitations on an individual, plant-by-plant basis. EPA says it must promulgate effluent limitations which shall be nationally uniform. In AFFI v. Train, supra, this court examined the language of the Act and its legislative history and again resolved this issue in favor of the Agency. The court said: As we have pointed out in Parts I and II, both the legislative history of the Act and its statutory structure and language mandate our rejecting the argument that the Act required the Administrator to set “guidelines” and “effluent limitations” for individual plants. We believe that Congress intended individual plant considerations to be taken into account within the nationally set effluent limitations in the granting of state permits under § 402(b) and (c). ... at 131. Although once again at odds with the view expressed by the Eighth Circuit in CPC International, supra, strong support for our position is found in similar holdings by the Second, Third, Fourth and Seventh Circuits. Hooker Chemicals & Plastics Corp. v. Train, supra; American Iron & Steel Institute v. EPA, supra, E. I. duPont de Nemours & Co. v. Train, 541 F.2d 1018, No. 74-1261 (4th Cir. 1976), cert. granted, - U.S. -, 96 S.Ct. 3165, 49 L.Ed.2d 1183 (1976) (Nos. 75-1473 & 75-1705) (duPont II); American Meat Institute v. EPA, supra. See also EPA v. State Water Resources Control Board, 426 U.S. 200, 96 S.Ct. 2022, 48 L.Ed.2d 578 (1976). Contrary to API’s fears, this interpretation will not reduce the function of the permit-granting authorities to that of a “clerical rubber stamping exercise.” As noted earlier in our discussion, there is a flexibility provision incorporated into the regulations for establishing effluent limitations guidelines for each of the five subcategories. This provision has recently been upheld by this circuit and two others. See AFFI v. Train, supra, E. I. duPont de Nemours & Co. v. Train (duPont II), supra, and Natural Resources Defense Council v. EPA, 537 F.2d 642 (2d Cir. 1976). Under the provision, the permit-granting authorities have a critical role to play: to define precisely the discharger’s obligations under the Act where “fundamentally different factors” require an adjustment in the effluent limitations established for the particular subcategory. As stated by the Second Circuit: Not all of the thousands of plants in operation can be expected to fit into prefabricated molds or templates. By specifying a permit procedure, Congress implicitly conferred on the permit-grantor the privilege of construing the broader regulations in light of the specific type of plant applying for the permit. Without variance flexibility, the program might well founder on the rocks of illegality. Natural Resources Defense Council v. EPA, supra, at 647. Accordingly, we reaffirm the view expressed in AFFI v. Train, supra, 539 F.2d at 131, that the EPA is to promulgate effluent limitations guidelines of a nationally uniform nature. C. Range API argues that the entire set of regulations is invalid because the Agency has established single number effluent limitations for each subcategory instead of a range of numeric values. In support of its “range” argument petitioners refer to the following statement in the Senate Report on the 1972 FWPCA amendments: In effect, for any industrial category, the Committee expects the Administrator to define a range of discharge levels, above a certain base level applicable to all plants within that category. EPA’s response is that it has fulfilled the Committee’s expectation. The Administrator has taken the pulp, paper and paperboard industrial category, divided it into two phases, and established five subcategories for the first phase. He has then assigned separate effluent limitations for each subcategory in Phase I. Thus, the individual numerical limitations for the five subcategories provide the “range” for Phase I of the pulp, paper and paperboard industrial category. In AFFI v. Train, supra, this court considered and rejected API’s argument. We approved EPA’s method of establishing single number effluent limitations because “the permit issuing authority under § 402 (state or federal) will clearly be able to employ any limitation it finds appropriate for a specific plant which falls between a ‘range’ of zero pollutant discharge and the nationally set .effluent limitations.” 539 F.2d at 140. On the facts presented to us, we add only that the Administrator has exercised reasonable discretion in subcategorizing the industry and establishing separate effluent limitations for the five subcategories of this phase of the industry. Although the Third Circuit has disapproved of this approach in American Iron & Steel Institute v. Train, supra, the Second and Fourth Circuits are in agreement with us. Hooker Chemicals & Plastics Corp. v. Train, supra, and E. I. duPont de Nemours & Co. v. Train (duPont II), supra. We affirm the Agency’s method of establishing single number discharge limitations for each subcategory of this industry. IV. SCOPE OF REVIEW [5,6] This court's authority to set aside agency action is governed by Section 10(e)(2)(A) of the Administrative Procedure Act, 5 U.S.C. § 706(2)(A) (1970). We may not interfere unless the agency’s action is “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law”. We may not substitute our judgment for that of the agency. Citizens to Preserve Overton Park v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814, 28 L.Ed.2d 136 (1971). We must ensure that a rational basis exists for the agency’s decision. Bowman Transportation, Inc. v. Arkansas-Best Freight Systems, Inc., 419 U.S. 281, 95 S.Ct. 438, 42 L.Ed.2d 447 (1974). This does not mean however that we must rubber-stamp agency decision-making. It is our duty to ensure that the agency’s decision is based on a consideration of all relevant factors. Our inquiry must be searching and careful, especially in highly technical cases such as the present one. Ethyl Corp. v. EPA, 176 U.S. App.D.C. 373, 541 F.2d 1 (1976) (en banc), cert. denied, 426 U.S. 941, 96 S.Ct. 2663, 49 L.Ed.2d 394 (1976). On this basis we proceed to an examination of the specific regulations being challenged. V. GENERAL VALIDITY OF REGULATIONS A. Cost Cost is one of the factors which the Administrator must consider in setting standards under the Act. Section 304(b)(1)(B) requires that he consider “the total cost of application of technology in relation to the effluent reduction benefits to be achieved” by the 1977 BPCTCA standard. This requires a cost-benefit analysis. Sections 304(b)(2)(B) and 306 mandate no such balancing. Under these sections the Administrator must consider only “the cost of achieving such effluent reduction” in establishing the 1983 effluent limitations guidelines and the new source performance standards. API contends that EPA’s assessment of the costs involved in setting these standards is inadequate in two respects: first, that the cost analysis undertaken by EPA is perfunctory and ignores economic considerations; and second, that the Agency has not engaged in a cost-benefit analysis for the 1977 standard as required by Section 304(b)(1)(B). We perceive no merit in either charge. The bulk of EPA’s cost analysis is contained in Section VIII and Appendix III of the Final Development Document. (App. 2409-2426; 2519-2548) Section VIII summarizes the costs of internal and external effluent treatment associated with the three technological levels prescribed by the Act — the 1977 BPCTCA, the 1983 BATEA and the new source performance standards. For each technology the cost of effluent treatment has been determined for the five subcategories established in this phase of the paper industry. (App. 2448, 2469, 2477) Tables showing internal and external controls for the five subcategories also indicate the investment costs, total annual costs, interest cost plus depreciation cost at 15% per year, and operating and maintenance costs. (App. 2419-2423) Appendix III of the Final Development Document presents a detailed description of the basis of the costs presented in the Section VIII tables. (App. 2519-2548) In addition, the Appendix delineates the internal and external technologies identified by the three levels of technology in terms of design limitations, unit processes and costs. Our study of these portions of the Final Development Document leads us to conclude that the Administrator’s analysis is neither arbitrary nor capricious. API’s second contention is that the Administrator has not engaged in a cost-benefit analysis for the 1977 BPCTCA as required by Section 304(b)(1)(B). Our examination of the record however negates this charge. In a 240-page report entitled Economic Analysis of Proposed Effluent Guidelines, Pulp, Paper and Paperboard Industry, the Agency, assisted by Arthur D. Little, Inc., engaged in a careful analysis of the total cost effects of the regulations and their impact on prices, production, employment, community, balance of payments and growth. (App. 735-955) As noted in the preamble to the published regulations, the total projected impact of 1977 BPCTCA technology includes 3%-6% price increases, 7 — 10 potential closures out of 188 mills, and 810-1,250 potential unemployed persons (representing 1.1%-1.6% of total employment for these mills). (App. 2203) In that portion of the preamble entitled “Cost-benefit analysis”, the Administrator concludes with this statement: The Agency believes that the benefits of thus reducing the pollutants discharged justify the associated costs which, though substantial in absolute terms, represent a relatively small percentage of the total capital investment in the industry. (App. 2203) Our review of the costs identified in Section VIII of the Final Development Document and the discussion of their impact in the Economic Analysis convinces us that there is firm record support for the Administrator’s conclusions. B. Non-water Environmental Impact and Energy Requirements Sections 304 and 306 of the Act require the Administrator to consider non-water quality environmental impact and energy requirements in establishing effluent limitations guidelines and new source performance standards. API argues that EPA has failed to fulfill this statutory obligation because it did not analyze energy costs and omitted consideration of certain environmental impacts. The Final Development Document shows that EPA did analyze the energy costs and requirements of the industry. (App. 2424-2426, 2448, 2469) After establishing both the power costs and energy requirements for all five subcategories under the 1977 BPCTCA standard, the 1983 BATEA standard, and the new source performance standard, (App. 2425-2426) the Administrator concluded that these energy considerations “are not substantial (less than 1 per cent [in the case of BPCTCA]) and should not be great enough to warrant concern on either a national or regional basis.” (App. 2448, 2469) In view of this assessment, the Administrator cannot be charged with failing to perform his statutory duty. We reach the same conclusion regarding the Agency’s consideration of the non-water environmental impact of these regulations. We note in the Final Development Document that the Administrator discusses air pollution, noise potential, solid waste disposal and by-product recovery. (App. 2427-2432) API takes the Administrator to task for failing to consider the impact of increased lime treatment and the implications of reuse of condensate streams. Our review of the Administrator’s discussion of non-water environmental impact does not convince us that his treatment of these issues constitutes arbitrary or capricious action. There is no indication that increased lime treatment is a significant factor or that the Administrator’s discussion of the air pollution problems does not encompass the problems inherent in reuse of condensate streams. Accordingly, we decline to find invalid this portion of his analysis. VI. THE 1977 EFFLUENT LIMITATIONS GUIDELINES EPA must establish effluent limitations guidelines for 1977 which reflect the application of “the best practicable control technology currently available (BPCTCA).” In the establishment of BPCTCA standards, Section 304(b)(1)(B) of the Act requires the Administrator to consider the following factors: (1) the total cost of application of technology in relation to the effluent reduction benefits to be achieved from such application; (2) the age of equipment and facilities involved; (3) the processes employed; (4) the engineering aspects of the application of various types of control techniques; (5) process changes; (6) non-water quality environmental impact (including energy requirements); and (7) such other factors as the Administrator deems appropriate. BPCTCA limitations will normally be established on the basis of the average performance of the best existing plants in each subcategory. Although the BPCTCA effluent standards will rely primarily on external (or “end of pipe”) treatment, internal control measures may be required if they are considered normal practice within the industry. As noted earlier, this unbleached phase of the pulp, paper and paperboard industry has been subdivided into five subcategories: unbleached kraft, sodium base neutral sulfite semi-chemical, ammonia base neutral sulfite semi-chemical, unbleached kraft— NSSC (cross recovery), and waste paperboard. For existing sources in each subcategory, the 1977 effluent limitations guidelines limit the discharge of three pollutants: “BOD5”, “TSS”, and “pH”. These terms require explanation: (a) BOD5. The initials “BOD” stand for “biochemical oxygen demand”. This is a measure of the oxygen consuming capabilities of organic matter. Dissolved oxygen in the water is consumed during decomposition of organic pollutants. Biochemical oxygen demand is commonly termed “BOD5” because the analytical techniques utilized for measurement involve a five-day period. (b) TSS. The initials “TSS” stand for “total suspended solids”. This is a measure of the materials suspended in a sample of water. Suspended solids in pulp and paper mill effluents are generally fibrous materials lost in the pulping of wood and the production of paper. (c) pH. This is a logarithmic expression of the concentration of hydrogen ions in a sample of waste water. It essentially describes the acidity or alkalinity of a water sample. At a pH of 7, the hydrogen and hydroxyl ion concentrations are approximately equal and the water is neutral. Lower pH values indicate acidity-while higher values indicate alkalinity. Final Development Document at 83-86. (App. 2309-2312) The 1977 effluent limitations guidelines permit the discharge of certain amounts of BOD5 and TSS expressed in pounds per ton of product (and kilograms per 1,000 kilograms of product) and the presence of a certain amount of pH for each subcategory. These limitations are set out in the following table. BPCTCA Effluent Limitations Values in kg/kkg (Ibs/ton) BOD5 TSS Subcategory 30 Day Daily Max 30 Day Daily Max Unbleached Kraft 2.8 (5.6) 5.6(11.2) 6.0 (12.0) 12.0(24.0) NSSC-Ammonia 4.0 (8.0) 8.0(16.0) 5.0 (10.0) 10.0(20.0) NSSC-Sodium 4.35(8.7) 8.7(17.4) 5.5 (11.0) 11.0(22.0) Unbleached Kraft-NSSC 4.0 (8.0) 8.0(16.0) 6.25(12.5) 12.5(25.0) Paperboard from Waste Paper 1.5 (3.0) 3.0( 6.0) 2.5 ( 5.0) 5.0(10.0) pH for all subcategories shall be within the range of 6.0 to 9.0. Final Development Document at 216 (App. 2442). A. Internal Control Measures API’s first challenge to the 1977 effluent limitations is that in order to meet the BOD5 limitations, the majority of mills in the industry will be required to make extensive internal changes in their equipment. This, API argues, contravenes the Act, which limits the 1977 standards to external treatment measures. API errs in believing that the FWPCA precludes in-plant control measures as part of the 1977 BPCTCA standard. The statute and the legislative history make clear that although BPCTCA standards are to rely principally on end-of-pipe treatment of waste water, internal control measures may be included if these measures are considered normal practice within the industry. The Final Development Document establishes that the in-plant changes which have been identified as available in 1977 are practices which are in common use in the pulp and paper industry. (App. 2443) Fully 60-100% of the mills within the five subcategories use some or all of the identified internal controls. Id. Moreover, the record discloses that at a technical meeting on April 4, 1974, API informed EPA that various in-plant control measures specifically identified by the Agency as BPCTCA were then common practices in the industry. (App. 2019-2025) Finally, we note that the Second and Fourth Circuits are in agreement with our position that internal control measures are permissible under the 1977 standard if they are considered normal practices within the industry. See Hooker Chemicals & Plastics Corp. v. Train, supra, 537 F.2d 620, as modified by Memorandum of June 14, 1976; duPont II, supra, 541 F.2d 1018; Tanners’ Council v. Train, 540 F.2d 1188, at 1191 (4th Cir. 1976); FMC Corp. v. Train (4th Cir. 1976) 539 F.2d 973, 981. B. Basis for 1977 Effluent Limitations Guidelines API’s second challenge to the 1977 effluent limitations is that they may not be based upon the average of the best performing mills in each subcategory, but must reflect only the average of the industry’s current performance. This argument is unpersuasive in light of the following statement by Senator Muskie in his discussion of the Conference Report: In defining “best practicable” for any given industrial category, the Committee expects the Administrator to take a number of factors into account. These factors should include the age of the plants, their size, the unit processes involved, and the cost of applying such controls. The Administrator should establish the range of “best practicable” levels based upon the average of the best existing performance by plants of various sizes, ages, and unit processes within each industrial category. In those industrial categories where present practices are uniformly inadequate, the Administrator should interpret “best practicable” to require higher levels of control than any currently in place if he determines that the technology to achieve those higher levels can be practicably applied. “Best practicable” can be interpreted as the equivalent of secondary treatment for industry, but this interpretation should not be construed to limit the authority of the Administrator. Leg.Hist. at 169-70. (Emphasis added.) Accord, American Meat Institute v. EPA, 526 F.2d 442, 453 (7th Cir. 1975); Hooker Chemicals & Plastics Corp. v. Train, supra, 537 F.2d at 633; Tanners’ Council v. Train, supra, 540 F.2d at 1191. We find no merit in API’s remaining contentions that EPA improperly used data showing maximum calendar month discharges to set effluent limitations and that unexplained discrepancies between the Draft and Final Development Document render the regulations invalid. On the first point, there is no inconsistency between the data and the regulations because both use twelve fixed-period daily averages per year. On the second point, because the Draft Development Document represents only a stage in the rulemaking process, subject to comment and change, there is no requirement that the Agency explain minor changes and refinements which inevitably result during such a process. C. Identification of Effluent Reduction API’s third challenge to the 1977 effluent limitations is that, contrary to the requirement of Section 304, EPA has failed to identify the degree of effluent reduction attainable through application of the best practicable control technology currently available. EPA contends that it has fully complied with Section 304 by establishing for each subcategory the quantity or quality of the various pollutants which may be discharged after application of the BPCTCA standard. We believe petitioners’ argument is more a matter of semantics than one of substance. Section 304(b)(1)(A) requires the Administrator to publish regulations providing guidelines for effluent limitations which identify, in terms of amounts of constituents and chemical, physical, and biological characteristics of pollutants, the degree of effluent reduction attainable through the application of the best practicable control technology currently available for classes and categories of point sources . . (Emphasis added.) This is precisely what EPA has done. It has (1) identified the three types of pollutants whose discharge must be limited under the 1977 standard (BOD5, TSS and pH), and (2) established in the regulations themselves the amounts of these pollutants which may be discharged in the five subcategories of this phase of the paper industry. We think this is a reasonable response to the statutory requirements and we reject the contention that EPA is also required to furnish data as to the pollution reduction which can be expected from the technologies which comprise the 1977 BPCTCA standard. If the Agency chooses to promulgate effluent limitations in the form of percentage removals, as it has done in the case of two subcategories of the 1983 color limitations, we would find this alternate method of establishing effluent limitations guidelines acceptable under the language of Section 304. However we do not believe that the above-quoted portion of Section 304(b)(1)(A) dictates to the Administrator that in adopting one or the other of these two methods he must also estimate how much reduction in pollution will be achieved as a result of the enunciated standard. D. 1977 BOD5 and TSS Limitations API’s fourth and final challenge to the 1977 effluent limitations is directed at the permissible amounts of B0D5 and TSS which may be discharged by mills under the BPCTCA standard. API contends that the 1977 BOD5 and TSS limitations cannot be met by the majority of mills performing at the “best practicable” level and therefore these limitations are invalid. In weighing petitioner’s argument, we must examine the method employed by EPA to establish these limitations. EPA’s technique for developing effluent limitations guidelines and new source performance standards is set out in the Agency’s notice of August .6, 1973. (App. 730) for 64 milis. Final effluent data from mill 30, 18 mills were finally chosen as best records was available for 30 mills. Of these performers. [T]he development of regulations for effluent limitations guidelines and standards of performance [is] undertaken in the following manner. The point source category is first studied for the purpose of determining whether separate limitations and standards are appropriate for different segments within the category. This analysis includes a determination of whether differences in raw material used, product produced, manufacturing process employed, age and size of plants, waste water constituents and other factors require development of separate limitations and standards for different segments of the point source category. The raw waste characteristics for each such segment are then identified. This includes an analysis of (1) the source, flow and volume of water used in the process employed and the sources of waste and waste waters in the plant; and (2) the constituents of waste waters. The constituents of the waste waters which should be subject to effluent limitations guidelines and standards of performance are then identified. Next, the control and treatment technologies existing within each segment are identified. This includes an identification of each distinct control and treatment technology, including both in-plant and end-of-process technologies, which exists or is capable of being designed for each segment. It also includes an identification of the effluent level resulting from the application of each of the treatment and control technologies, in terms of the amount of constituents and the chemical, physical, and biological characteristics of pollutants. The problems, limitations and reliability of each treatment and control technology are also identified. In addition, any non-water quality environmental impact, such as the effects of the application of such technologies upon other pollution problems, including air, solid waste, noise and radiation is examined. Finally, the energy requirements of each control and treatment technology are determined, as well as the cost of the application of such technologies. This information is then evaluated in order to determine what levels of technology constitute the “best practicable control technology currently available”, “best available technology economically achievable” and the “best available demonstrated control technology, processes, operating methods, or other alternatives.” In identifying such technologies, various factors are considered including the total cost of the application of technology in relation to the effluent reduction benefits to be achieved from such application, the age of equipment and facilities involved, the process employed, the engineering aspects of the application of various types of control techniques, process changes and non-water quality environmental impact (including energy requirements). (App. 731) The accumulation of information from this process resulted in a large data base. As shown in the following table, the total number of mills included in the subcategories under study was 218 of which 84 discharged to municipal systems. Of the 134 mills discharging to receiving waters, raw waste data from mill records was available NUMBER OF MILLS PER SOURCE OF INFORMATION Subcategory m . . Mill Records, NCASI Total Discharging Discharging --- Number To To Receiving Raw of Mills Municipal Waters Final Best Waste Effluent (a) Performers Unbleached Kraft 27 0 27 24 12 NSSCSodium 14 1 13 6 3 NSSCAmmonia 2 0 2 1 1 Kraft-NSSC 10 0 10 10 4 Paperboard-Waste Paper 165 83 82 23 9(b) Totals 218 134 30 18 (a) Effluents from biological treatment (b) One of the nine mills only had primary treatment (App. 2242) EPA’s method of choosing “best performers” for each subcategory is based on data contained in Sections III, V, VII and VIII and in the Appendices of the Final Development Document. Following the accumulation and analysis of information and data from every available source, best performing mills were chosen on the basis of those mills in each subcategory with the lowest current levels of pollution discharge. This is best illustrated by the following example. In the unbleached kraft subcategory, raw waste data were available for 24 of the 27 mills. Final effluent data were available for 12 of these 27. After these data were examined six of the seven unbleached kraft mills achieving the best final effluent qualities in the country were selected as best performers. (App. 2450-2451) (The mill achieving the best final effluent quality in this subcategory, mill UK-3, was not included as a best performer because its external treatment system was judged to be atypical of the subcategory.) (App. 2449) The best performers in this subcategory are found in Tables 61 and 62 of the Final Development Document. (App. 2450 — 2451) Once the Agency had selected its “best performers” it was in position to determine the effluent limitations guidelines for the 1977 BPCTCA standard. As previously mentioned, the legislative history demonstrates that Congress required EPA to establish 1977 effluent limitations based on “the average of the best existing performance by plants of various sizes, ages, and unit processes within each industrial category.” Leg.Hist. 169, 1468. (Emphasis added.) To continue our example of the unbleached kraft subcategory, Tables 61 and 62 provide us with the following information about the six best performers: Final Effluent Data Showing Maximum Monthly Discharges of BOD5 and TSS in kg/kkg (lbs/ton) Mill BOD5 TSS UK-1 2.3 (4.6) 6.1 (12.1) UK-2 1.3 (2.7) 3.8 ( 7.6) UK-5 3.1 (6.1) 7.1 (14.2) UK-6 3.7 (7.4) 3.9 ( 7.9) UK-7 3.1 (6.2) 4.6 ( 9.3) UK-8 3.3 j6.6) 3.5 ( 7.0) Average 2.8 (5.6) 4.8 ( 9.7) (App. 2450-2451) The 1977 BOD5 limitation finally established by EPA for the unbleached kraft subcategory was the figure derived from averaging the B0D5 figures from the six best performers: 2.8 (5.6). Ordinarily the 1977 TSS limitations would have been the average of the TSS discharge figures from these same six dischargers, but in this particular subcategory a less stringent limitation was finally selected because of practical considerations. (1) BOD5 API’s attack on the 1977 BOD5 limitations is based on a discussion of “percentage removals”. API equates the 1977 BPCTCA for removal of BOD5 at 85% and then presents calculations to show that in reality EPA is requiring treatment systems which must be capable of removing 92% of the annual average BOD5. This, API argues, exceeds what EPA has identified as BPCTCA. The flaw in petitioners’ argument is that the 85% figure has not been used by the Agency to define the 1977 BOD5 limitation. It is not in the regulation establishing the effluent limitations guidelines for BOD5 and does not appear in that section of the Final Development Document discussing the BPCTCA standard. Although there is one reference to an 85% BOD, removal figure in a discussion of secondary treatment systems in Appendix III of the Final Development Document, four district biological units are analyzed there and in the analysis of only one — natural oxidation ponds — does this figure appear. (App. 2536) It appears that API has taken this figure out of context, misapplied it, and now criticizes the Agency for requiring limitations which exceed it. We therefore regard petitioners’ discussion of percentage removals as irrelevant in the context of the 1977 BOD5 limitations and uphold these regulations as promulgated. (2) TSS API says the 1977 TSS limitations are invalid because the Agency has failed to specify technology capable of removing “non-settleable biological solids” and has not stated what “percentage of reduction” of this material can be achieved by the operations EPA describes. EPA responds that these allegations are irrelevant: because the TSS limitations are based on actual waste water treatment performance data, the settleability of biological solids and the reduction capabilities of the identified technologies are included in the final effluent TSS levels. Although EPA’s response is satisfactory to us on both points, we are unpersuaded by API’s arguments for additional reasons. First, we find unsound petitioners’ method of framing an argument on the basis of definitions not employed by the Agency and not found in the record. The absence of any discussion of the “non-settle-able” nature of biological solids reinforces our view of the validity of the TSS limitations as promulgated. Second, we have already considered and rejected API’s “percentage reduction” argument. As we said in discussing API’s third challenge to these effluent limitations guidelines, EPA is in full compliance with Section 304(b)(1)(A): it has (1) identified the pollutants whose discharge must be limited under the 1977 standard (BOD5, TSS and pH), and (2) established in the regulations themselves the amounts of these pollutants which may be discharged in the five subcategories of this phase of the paper industry. EPA is not required to furnish data as to the pollution reduction or “percentage reduction” which can be expected from the technologies which comprise the 1977 BPCTCA standard. Finding no merit in any of petitioners’ challenges to the 1977 effluent limitations guidelines, we uphold these limitations. VII. THE 1983 EFFLUENT LIMITATIONS GUIDELINES EPA must establish 1983 effluent limitations guidelines which reflect application of “the best available technology economically achievable (BATEA).” In establishing BATEA standards, Section 304(b)(2)(B) of the Act, 33 U.S.C. § 1314(b)(2)(B), requires the administrator to consider the following factors: (1) the age of equipment and facilities involved; (2) the process employed; (3) the engineering aspects of the application of various types of control techniques; (4) process changes; (5) the cost of achieving such effluent reduction; (6) non-water quality environmental impact (including energy requirements); and (7) such other factors as the Administrator deems appropriate. The distinction between the 1977 BPCTCA standard and the 1983 BATEA standard is explained succinctly by Senator Muskie in his discussion of the Conference Report: In making the determination of “best available” for a category or class, the Administrator is expected to apply the same principles involved in making the determination of “best practicable” (outlined above), except as to cost-benefit analysis. Also, rather than establishing the range of levels in reference to the average of the best performers in an industrial category, the range should, at a minimum, be established with reference to the best performer in any industrial category. The distinction between “best practicable” and “best available” is intended to reflect the need to press toward increasingly higher levels of control in six-year stages. Through the research and development of new processes, modifications, replacement of obsolete plans and processes, and other improvements in technology, it is anticipated that it should be possible, taking into account the cost of controls, to achieve by 1983 levels of control which approach and achieve the elimination of the discharge of pollutants. As to the cost of “best available” technology, the Conferees agreed upon the language of the Senate Bill in Section 304(b)(2). While cost should be a factor in the Administrator’s judgment, no balancing test will be required. The Administrator will be bound by a test of reasonableness. In this case, the reasonableness of what is “economically achievable” should reflect an evaluation of what needs to be done to move toward the elimination of the discharge of pollutants and what is achievable through the application of available technology — without regard to cost. Leg.Hist. at 170. To a certain extent, the 1983 limitations must be anticipatory because no one can possibly know with certainty what will be “the best available technology economically achievable” in 1983. But we do know that the 1983 level of pollution control must be stringent enough to make possible the attainment of the ultimate goal of the Act: the complete elimination of pollution discharges to the Nation’s waters by 1985. In light of this, EPA’s 1983 effluent limitations guidelines must be upheld if the Agency can demonstrate that by 1983 there will be a technology which, if implemented, may reasonably be expected to achieve the standard. For existing sources in each subcategory of this phase of the pulp and paper industry the 1983 effluent limitations guidelines seek to regulate the discharge of four pollutants: BOD5, TSS, pH and “color”. The “color” pollutant results from the various chemical pulping processes of the industry. Spent cooking liquors containing highly colored compounds are removed from the pulp in a washing sequence following the cooking process. The wash water is highly colored and large amounts of color are ultimately discharged into receiving streams. This color ranges from brown to black. EPA seeks to regulate the discharge of this pollutant for four of the five subcategories. For two subcategories (unbleached kraft and unbleached kraft — NSSC (cross recovery)) specific color controls are set in terms of pounds of color per ton of production (and its metric counterpart). For the other two subcategories (ammonia base neutral sulfite semi-chemical and sodium base neutral sulfite semi-chemical) color control is expressed in terms of percentage removal rather than maximum allowed mass units. The 1983 point source discharge limitations for each of the four pollutants for this unbleached phase of the pulp and paper industry are set out in the following table, found in the Final Development Document. (App. 2464) BATEA Effluent Limitations Values in kg/kkg (Ibs/ton) BOD5 TSS Subcategory 30 Day Daily Max 30 Day Daily Max Unbleached Kraft 1.35(2.7) 2.7 ( 5.4) 1.85 ( 3.7) 3.7 ( 7.4) NSSC-Ammonia 3.2 (6.4) 6.4(12.8) 2.6 ( 5.2) 5.2(10.4) NSSC-Sodium 2.25(4.5) 4.5 ( 9.0) 2.5 ( 5.0) 5.0(10.0) Unbleached Kraft-NSSC 1.6 (3.2) 3.2 ( 6.4) 2.1 ( 4.2) 4.2 ( 8.4) Paperboard from Waste Paper 0.65(1.3) 1.3 ( 2.6) 0.8 ( 1.6) 1.6 ( 3.2) Color Subcategory 30 Day Daily Max Unbleached Kraft 10 (20) 15 (30) NSSC-Ammonia 75% removal NSSC-Sodium 75% removal Unbleached Kraft-NSSC Paperboard from Waste Paper 12.5 (25) 25.0 (37.5) pH for all subcategories shall be within the range of 6.0 to 9.0 A. 1983 BOD5 Limitations API’s first challenge is directed at the 1983 BOD5 limitations. These limitations are based on a specific achievable raw waste load for each subeategory. Final limitations are derived by applying to the raw waste load for each subcategory percentage reductions currently achievable by identified external treatment technologies. API’s challenge to these limitations is that there is no rational basis to support the raw waste loads for each subcategory. Table 71 of the Final Development Document (App. 2471) provides the figures being challenged by API. The raw waste loads for the five subcategories are as follows: Subcategory Raw Waste kg/kkg (Ibs/ton) Unbleached Kraft 12.5 (25) Sodium-NSSC' 17.5 (35) Ammonia-NSSC 25 (50) Kraft-NSSC 15 (30) Paperboard-Waste Paper 10 (20) (App. 2471) API takes the unbleached kraft subeategory as an example and argues that there is no support in the Final Development Document for the BOD5 waste load figure of 25 pounds per ton of production. In this we think they err. EPA projected the raw waste loads, upon which the 1983 limitations are based, on actual raw waste data for mills operating today. As shown in Table 13 of the Final Development Document (App. 2282) the raw waste load used as a basis for the 1983 limitation for the unbleached kraft subcategory is that load currently being attained by Mill UK-2. The raw waste BOD for this mill is 24.5 pounds per ton, which EPA rounded up to 25. The raw waste loads for the other four subcategories were derived from similar tables showing mills presently achieving comparable or in some cases lower amounts of raw waste loads. See Tables 14, 18, 19 and 21, Final Development Document. (App. 2288, 2296, 2299-2302) Thus contrary to petitioners’ assertions, the Agency evidences a rational basis for selecting raw waste loads for each subcategory. In light of this we conclude that API’s challenge to the 1983 BOD5 limitations is without merit and we uphold these regulations as promulgated. B. 1983 TSS Limitations API challenges the 1983 TSS limitations on two grounds. First, says API, the technology of mixed media filtration has not been demonstrated in actual paper mill waste treatment systems and therefore should not be included as technology for the 1983 standard. Second, API says the Agency has failed to explain its method of calculating final TSS limitations and thus its action is arbitrary and capricious. In light of our examination of the record we reject both contentions. As explained in Section X of the Final Development Document the 1983 limitations guidelines were determined by using the 1977 TSS limitations as a base and then applying a reduction figure of 60%. This figure was derived from Agency estimates that application of coagulation and filtration technology, including mixed media filtration, would remove 60% of the TSS from biological treatment effluent. Final Development Document at 244. (App. 2470) Although petitioners now contend that mixed media filtration technology has not been actually demonstrated, statements by industry representatives and reports from industry sources contradict this assertion. The first item in the record which contradicts API is a technical bulletin by the National Council of the Paper Industry for Air and Stream Improvement (NCASI) dated May 1973. (App. 1728) This industry bulletin contains the results of a NCASI study of mixed media filtration at three different mills. The study indicates that the three different types of mills were successful in removing significant amounts of TSS effluents with mixed media filtration. With the use of chemical additives, two of the three systems were able to remove as much as 96% and 97% of the TSS material present. (App. 1740) The. second record item refuting petitioners’ contention that mixed media filtration is not a demonstrated technology is a statement by Peter Wrist, Vice President of the Mead Corporation (one of the petitioners) and Chairman of the Board of NCASI, acknowledging that mixed media filtration has shown the potential of removing the TSS material in the amounts estimated by EPA. At an EPA technical hearing on April 4, 1974, following publication of the proposed limitations, Mr. Wrist stated: I would like to comment now on the advanced biological solids treatment techniques. The document indicates that in the proposed standards for BATEA and NSPS that there will be the use of mixed media filters for post-clarification of biological solids. It is further indicated that with the use of this technique a further reduction of sixty percent of the level leaving the secondary basis is achievable. The industry has been experimenting with this technique in a number of locations on a pilot-plant scale. We would agree that based on the very limited testing that we have seen, that this level of percentage reduction is achievable. (App. 1971-1972) This evidence effectively rebuts API’s argument that mixed media filtration is not a demonstrated technology. We believe the Administrator, in selecting this particular technology, has shown that mixed media filtration may reasonably be expected to achieve the 1983 TSS standard. We turn to API’s second argument on the invalidity of these TSS limitations. API argues that the Agency has failed to explain its method of calculating final TSS limitations. Once again, taking the unbleached kraft subcategory as an example, API contends that it is not apparent how the Agency arrived at 3.7 pounds of TSS per ton. EPA’s calculations, as set out in the record (App. 3545 et seq.) and as explained in its brief, (pp. 86 et seq.) are as follows: First, in the unbleached kraft subcategory, reduce the 1977 TSS limitations (12.0) by 60% to account for the predictable effect of filtration and coagulation. This yields 4.8 pounds per ton. Second, determine fr