Task: songer_casetyp1_7-2

What follows is an opinion from a United States Court of Appeals.
Your task is to identify the issue in the case, that is, the social and/or political context of the litigation in which more purely legal issues are argued. Put somewhat differently, this field identifies the nature of the conflict between the litigants. The focus here is on the subject matter of the controversy rather than its legal basis.
Your task is to determine the specific issue in the case within the broad category of "economic activity and regulation". 

LEVIN H. CAMPBELL, Circuit Judge.
We are asked to review the Metropolitan Boston Air Quality Transportation Control Plan (theplan).
The plan is aimed at keeping two types of air-borne pollutants, photochemical oxidants and carbon monoxide, from exceeding within Greater Boston the national primary and secondary ambient air quality standards prescribed by the Environmental Protection Agency (EPA) under authority of the Clean Air Act. In the Act, Congress has directed EPA, using latest scientific knowledge, to establish nationwide air-quality standards for each pollutant having an adverse affect upon the public health or welfare. 42 U.S.C. § 1857c-4. It has further directed each state to have a plan to “implement” those standards— that is, to see that within the state the level of each such pollutant does not exceed limits prescribed in the national standards.
The present plan (termed a “transportation” control plan because it focuses upon pollutants caused mainly by vehicles rather than by “stationary sources” like factories, incinerators, and power plants) has been recognized from the outset to present delicate problems; inevitably it seems bound to come between the citizen and his automobile. Indeed the problems were seen to be so novel and difficult, that the EPA Administrator initially postponed compliance dates from mid-1975 to 1977; however, it was held that he lacked authority to do so. See Natural Resources Defense Council, Inc. v. EPA, 154 U.S.C.App.D.C. 384, 475 F.2d 968 (1973).
The Administrator finally ordered Massachusetts to submit its transportation control plan by April 15, 1973. When Massachusetts did not submit an acceptable plan, the Administrator, as he is obliged to do under such circumstances, promptly proposed a plan of his own for the state, held a public hearing and, after making changes in the plan he had first proposed, promulgated regulations embodying the final plan before us.
The plan is designed, by May 31, 1975, to reduce the expected emission of hydrocarbons in the Metropolitan Boston Intrastate Region by 58 percent, and of carbon monoxide in the Boston core and East Boston area of the region by about 40 percent. The Administrator has determined that reductions of this magnitude are necessary if the region’s air is to conform to national standards by that date, which is the compliance date set by Congress.
At the heart of the plan is a strategy of cutting down emissions by discouraging the use of vehicles. Off-street and on-street parking spaces are to be “frozen” or cut back, and the construction of new parking facilities is regulated. There are to be special bus and car pool lanes, and a computer car pool matching system. There is also to be a program of vehicle inspection and maintenance and emission exhaust controls, including oxidizing catalysts, air bleed emission controls and a vacuum spark disconnect. Finally, there are controls on some stationary sources, including gasoline sales outlets, to prevent hydrocarbon emission.
Many aspects of the plan are attacked by affected entities and individuals, although we note that the City of Boston registers its support. The separate petitions for review were consolidated and are herein decided together.
I
STANDARD OF REVIEW
In providing for review of an implementation plan under the Clean Air Act by courts of appeals, Congress did not lay down standards beyond those already established in the Administrative Procedure Act (APA). The latter standards, appearing in 5 U.S.C. § 706, are controlling. See Citizens to Preserve Overton Park v. Volpe, 401 U.S. 402, 413, 91 S.Ct. 814, 28 L.Ed.2d 136 (1970); Texas v. EPA, 499 F.2d 289, at 296 (5th Cir. 1974). Under § 706, we must determine whether EPA followed lawful procedures in evolving its plan; whether it acted within its statutory authority; and whether the plan is constitutional. If so, we must set aside the plan only if it is found to be “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law ’. 5 U.S.C. § 706(2) (A).
In the following parts of this opinion we deal first with the procedural objections to the plan and later with the constitutional ones. In between we consider statutory objections and, most difficult of all, those objections addressed to the merits of the plan. The last objections, it is clear, are outside our province unless they show that EPA’s decision was not based on consideration of relevant factors or else included. a “clear error of judgment”. Overton Park, supra, 401 U.S. at 416, 91 S.Ct. 814. We are not empowered to substitute our judgment for that of the agency.
The questions about the plan on review are of two types: the rationality of EPA’s technical decisions (such as its determinations of local photochemical oxidant and carbon monoxide levels and the amount of reductions required to meet national standards), and the rationality of EPA’s “control strategy”, that is, the measures adopted to reduce emissions. The former present peculiar difficulties for nonexperts to evaluate. Yet “[our] inquiry into the facts is to be searching and careful”, id., and we must assure ourselves as best we can that the Agency’s technical conclusions no less than others are founded on supportable data and methodology and meet minimal standards of rationality. See Section III infra.
Assuming EPA’s technical determinations are reasonably based,' we must decide whether the selected controls are arbitrary or capricious. In so doing, we must bear in mind that Congress lodged with EPA, not the courts, the discretion to choose among alternative strategies. Unless demonstrably capricious — such as much less costly but equally effective alternatives were rejected or the requisite technology is unavailable — the Administrator’s choices may not be overturned. See Friends of the Earth v. EPA, 499 F.2d 1118, at 1123 (2d Cir. 1974); Delaware Citizens for Clean Air, Inc. v. EPA, 480 F.2d 972, 975-976 (3d Cir. 1973). Of course neither EPA nor this court has any right to decide that it is better to maintain pollutants at a level hazardous to health than to require the degree of public sacrifice needed to reduce them to tolerable limits.
We now turn to the objections.
II
PROCEDURAL OBJECTIONS
A. Notice
Several petitioners charge that the final plan differed so radically from the one proposed in the Administrator’s published notice that they had no meaningful forewarning of its substance.
Notice of a proposed rulemaking must be published in the Federal Register. It must include “either the terms or substance of the proposed rule or a description of the subjects and issues involved.” 5 U.S.C. § 553(b)(3). The Administrator published notice on July 2, 1973. 38 Fed.Reg. 17689 (1973). Two days of public hearings were then held in Boston on July 19 and 20, 1973, after which the record remained open for submission and public inspection of written comments until August 1, 1973. The final plan was published November 8, 1973.
In his notice, the Administrator asserted that levels of photochemical oxidants and carbon monoxide in parts of the Boston region already exceeded on many days the national primary standards promulgated as necessary to public health, and concluded that,
“it will be necessary to reduce projected total emissions of hydrocarbons within the area encompassed by Route 128 by approximately 58 percent and to reduce projected emissions of carbon monoxide in the Boston core and East Boston areas of the Region by amounts approximating 40 percent in each area....”38 Fed.Reg. 17691 (1973).
The. Administrator wrote that carbon monoxide emissions came almost entirely from motor vehicle sources and that most hydrocarbons which make up photochemical oxidants came from the same source. Analyzing transportation control alternatives — reducing vehicular emissions or reducing vehicle miles of travel (VMT) — the Administrator outlined a policy also supported by the Governor of Massachusetts “to discourage continued heavy reliance on the automobile”. Thus the proposed, as well as final, regulations stress VMT reducing controls.
The Administrator’s specific proposals first included a ban on on-street parking in the Boston core area from 6 to 10 a. m. and 4 to 6 p. m. on weekdays, and a $5 surcharge on off-street parking from 6 to 10 a. m. in the core area and from 6 a. m to 10 p. m. at Logan International Airport (Logan). To reduce photochemical oxidants he proposed prohibiting travel within Route 128 (an expressway circling Boston) one day out of five, by a sticker system. However, the Administrator noted that there was a legal question concerning EPA’s authority to propose regulatory fees, and also said that the sticker system might be replaced if preferable measures were suggested. He warned that alternatives were being considered including:
“Making effective reductions in the number of parking spaces available for use in downtown Boston between 6 a. m. and 10 a. m., and at Logan airport between 6 a. m. and 10 p. m.
“Making a similar reduction in the number of available parking spaces (both on- and off-street) in parking facilities at other trip-attraction center throughout the Metropolitan area.” 38 Fed.Reg. 17692 (1973).
Interested persons were notified that a technical support document was available. Finally, the Administrator said the final plan should reflect local needs and, therefore,
“particularly invited [comments] pertaining to the other measures that may be taken by Federal, State, or local authorities to support or supplement the proposed air pollution control measures.... The Administrator’s final promulgation of transportation controls... will be influenced by the comments and testimony he receives, as well as by any further approvable strategies submitted by the State as part of the State Implementation Plan. These influences, and the additional analysis of alternative strategies that can be made in the time between this proposal and final promulgation, may lead the Administrator to adopt final regulations that differ in important ways from this proposal.” Id. at 17694.
When the final plan emerged, it was, indeed, much influenced by the public hearing. The $5 surcharge and the sticker system, both of which had been sharply criticized, were dropped, as was a proposal to limit the supply of gasoline. Substituted were a much smaller surcharge and an egress toll on vehicles leaving Logan; pre-construction review of new parking facilities throughout the region; a freeze on parking spaces in selected portions of the metropolitan region; reduction in employee parking spaces; and reductions in the number of off-street parking spaces available in the Boston core during morning rush hours. The parking surcharge and egress toll were subsequently deleted. 39 Fed.Reg. 1848 (1974)..
The final plan added regulations for computer car pool matching and preferential treatment throughout the region for bus/car pools. It made changes in the- controls on mobile source emissions, and required vehicles to be inspected twice a year instead of once.
Although the changes were substantial, they were in character with the original scheme and were additionally foreshadowed in proposals and comments advanced during the rulemaking. Parties had been warned that strategies might be modified in light of their suggestions. When the hearing opened, the Regional Administrator said,
“if you suggest any part of the plan be eliminated, then we are going to have to make that emission reduction by some other kind of control, and we are anxious to receive your recommendation as to what that could be.”
Governor Sargent, speaking first, advocated freezing the number of parking spaces, mentioning Logan Airport. But the Governor would have let the new South Terminal parking garage at Logan and other new projects go forward if the Massachusetts Port Authority (Massport) and Boston phased out “older, less efficient and less conveniently situated spaces in equivalent number to the new spaces being created.” He also recommended a 10 to 20 percent parking vacancy rate before 10 a. m. and a 10 to 20 percent reduction in the ratio of parking spaces to employees.
One state representative suggested banning further construction of parking garages and reducing the surcharge to $2. The Chairman of the City of Boston Air Pollution Control Commission advocated both a parking freeze on commuter spaces with new parking only if an equal number of other spaces are eliminated, and a rollback of commuter parking before 10 a. m. The Regional Administrator expressed interest in his proposals. The Commission’s Executive Director also suggested a parking freeze in the downtown area and at related locations. The Boston Redevelopment Authority proposed replacing the surcharge with an early morning vacancy rate. The possibility of pegging this figure at 40 percent, as later decided, was discussed. One of the petitioners, Mr. Meyers, President of the New England Parking Association, was asked by the Regional Director which alternative — $5 surcharge or “restricting parking spaces utilized during the day, say 6 a. m. to 10 a. m.” — was considered most equitable from the standpoint of the parking facilities industry. Throughout the hearing, that choice was repeatedly explored. Other persons suggested eliminating all open-air parking lots, a “head on assault on the availability of parking spaces, particularly in open-air parking lots and older garages”, and reducing parking facilities where plants can be served by mass transit. One City Councillor suggested that no parking facility be allowed to park ears between 6 and 10 a. m.
We conclude that interested persons were sufficiently alerted to likely alternatives to have known what was at stake. In the published notice, mention had been made of alternative measures for “effective reductions” in the number of parking spaces in downtown Boston, Logan Airport and “other trip attraction centers throughout the metropolitan area”. EPA made plain its intention to adopt “stringent controls”. South Terminal is unconvincing when it argues that the “effective” reduction at Logan (from 6 a. m. to 10 p. m.) applied only to “limited periods of the day” and did not, therefore, give notice that anything as drastic as a freeze might be adopted. The proposed surcharge was expected to reduce South Terminal’s parking by 35 percent. The final plan was in some ways more moderate than the original. Cf. California Citizens Band Ass’n v. United States, 375 F.2d 43 (9th Cir. 1967).
A hearing is intended to educate an agency to approaches different from its own; in shaping the final rule it may and should draw on the comments tendered. The plan seems a logical outgrowth of the hearing and related procedures. Cf. Mt. Mansfield Television, Inc. v. FCC, 442 F.2d 470 (2d Cir. 1971). Parties have no right to insist that a rule remain frozen in its vestigal form. See Pacific Coast European Conference v. United States, 350 F.2d 197, 205 (9th Cir. 1965). As the Court of Appeals for the District of Columbia Circuit recently said:
“The requirement of submission of a proposed rule for comment does not automatically generate a new opportunity for comment merely because the rule promulgated by the agency differs from the rule it proposed, partly at least in response to submissions.
International Harvester Co. v. Ruckelshaus, 155 U.S.App.D.C. 411, 478 F.2d 615, 632 n. 51 (1973). See also Owensboro on the Air, Inc. v. United States, 104 U.S.App.D.C. 391, 2'i2 F.2d 702, 708 (1958).
Cases cited by petitioners in which there was no notice or opportunity to comment or submit evidence are not in point, nor is their reliance on Wagner Electric Corp. v. Volpe, 466 F.2d 1013 (3d Cir. 1972). A circumscribed announcement, as in the latter case, that standards for testing an automotive product would be revised, is not to be compared to EPA’s comprehensive notice. The former did not make it clear that interrelated aspects, such as performance criteria, would also be considered. The instant notice left no doubt that EPA would consider all reasonable alternatives for cutting down vehicle use.
Some petitioners also claim inadequate notice of technical documents upon which EPA relied. Yet save for South Terminal and Massport, they do not point to specific information not available before the hearing which they now dispute. EPA stated in its published notice that a technical support document was available. That referred to previous studies which, had they been sought out, would have been found to include consultants’ technical reports. There is no evidence that access to any of this material was ever requested or, having been requested, was denied by EPA. Portland Cement Ass’n v. Ruckelshaus, 158 U.S.App.D.C. 308, 486 F.2d 375, 392 (1973), cert. denied, 417 U.S. 921, 94 S.Ct. 2628, 41 L.Ed.2d 226 (1974), upon which petitioner relies, deals with an entirely different set of facts — critical test results were not available, and the Agency refused to respond to legitimately voiced problems with its methodology. The present technical support document explained in some depth the basis for the Agency’s conclusion that emission reductions were necessary. Post-hearing documents furnished by EPA 'were in response to issues there raised by the public and, except for new information on Logan, supply no data petitioners would have needed to raise the questions they now pose.
We thus reject petitioners’ contentions both of inadequate notice and of inadequate disclosure of underlying technical data.
B. Adjudicatory Hearings
A further procedural contention is that “adjudicatory” rather than “informal rulemaking” hearings should have been held. The APA calls for an adjudicatory hearing only when the statute requires rules to be “made on the record” after an agency hearing. 5 U. S.C. § 553(c). Statutes which merely authorize rulemaking “after hearing” do not trigger all the procedures of §§ 556 and 557. United States v. Florida East Coast R.R., 410 U.S. 224, 93 S.Ct. 810, 35 L.Ed.2d 223 (1973); United States v. Allegheny-Ludlum Steel Corp., 406 U.S. 742, 92 S.Ct. 1941, 32 L.Ed.2d 453 (1972). A “public hearing” is to be held before a state implementation plan is promulgated by the Administrator. 42 U.S.C. § 1857c-5(c). But there is no indication that Congress intended the words “public hearing” to be tantamount to “on the record”.
Petitioners concede that the language in the Clean Air Act does not trigger the APA’s adjudicatory guidelines. They contend, however, that the due process clause requires a full evidentiary hearing because the plan affects “vital, clearly identifiable economic interests” and is “condemnatory in purpose”. At such a hearing, petitioners say, they would present evidence refuting the plan’s technological and economic feasibility, as well as the underlying scientific data.
The opportunity for oral as well as written comment was granted here. Cf. Walter Holm & Co. v. Hardin, 145 U.S.App.D.C. 347, 449 F.2d 1009 (1971). Petitioners did not at the hearing demand any more expansive procedures. Moreover, economic and technical factors pertaining to the creation of a regional plan are not usually “adjudicative” facts. See, e. g., O’Donnell v. Shaffer, 491 F.2d 59 (D.C. Cir. 1972); American Airlines, Inc. v. CAB, 123 U.S.App.D.C. 310, 359 F.2d 624, 633 (D.C. Cir.), cert. denied, 385 U.S. 843, 87 S.Ct. 73, 17 L.Ed.2d 75 (1966). See generally 1 K. C. Davis, Administrative Law Treatise ft 7.02 (1958). The end product was to be a rule of general application; like legislation (which may also have severe impact) such a rule need not be conceived in a trial-type proceeding. Courts have unanimously rejected the argument that EPA must provide full adjudicatory hearings simply because cost and technological feasibility are disputed. See International Harvester Co. v. Ruckelshaus, supra, 478 F.2d at 629; Anaconda Co. v. Ruckelshaus, 482 F.2d 1301, 1306-1307 (10th Cir. 1973); Buckeye Power, Inc. v. EPA, 481 F.2d 162, 172 (6th Cir. 1973); Duquesne Light Co. v. EPA, 481 F.2d 1, 6-7 (3d Cir. 1973).
Any rulemaking should, of course, be tailored to elicit maximum information and input consistent with the agency’s aims and timetable. Cf. International Harvester Co., supra, 478 F.2d at 630-631. But petitioners are poorly situated to complain now of procedural details. They did not do so before or during the hearing, and few even availed themselves fully of the opportunities for comment that were tendered. They made no request to call or examine witnesses. Had they done so, we would not have required EPA to recognize such requests as of right; but the Agency itself in its own discretion might have thought it sensible to afford the privilege upon a “circumscribed and justified request.” Id. at 631.
. South Terminal, being the only facility in construction which may increase parking spaces in a freeze zone by more than 10 percent, is uniquely affected by part of the plan. But there is no evidence that the decision to treat Logan separately from Boston was anything but a genuine “legislative” judgment by the Agency. [I]n no sense [is the regulation] a punishment for sins of commission or omission” by South Terminal; it bears all the indicia of a good faith attempt to deal with what the Agency considered a serious pollution problem over East Boston, of which the airport is a key part. A similar claim was rejected in Anaconda Co., supra, 482 F.2d at 1306-1307, in which part of a state implementation plan written in general terms resulted in a duty upon only one plant — the area’s major source of pollution. Because both the rule and the pollutants affected many persons beyond the solitary polluter, the court concluded that an adjudicatory hearing was not required nor even manageable in view of the many possible interested parties.
The present rule does not deal with named parties and had, as its focus, an appropriate general, regulatory purpose. We agree that,
“[The] Constitution should not be held to require participatory rights for persons affected by agency rule-making but not named as parties, unless the agency adopted a rule without a general purpose and with the intent of affecting only a specific person.
Note, The Judicial Role in Defining Procedural Requirements for Agency Rule-making, 87 Harv.L.Rev. 782, 788, n. 40 (1974). We hold that rulemaking rather than adjudication proceedings were in order.
C. Impact Statement
Since oral argument the Energy Supply and Environmental Coordination Act of 1974 has become law, providing, “No action taken under the Clean Air Act shall be deemed a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969.” Pub. L.No. 93-319, § 7(c)(1) (June 22, 1974). This nullifies petitioners’ claim that EPA • was required to prepare a NEPA environmental impact statement pursuant to 42 U.S.C. § 4332(2) (C).
III
WHETHER EPA COMMITTED A CLEAR ERROR OF JUDGMENT IN COMPUTING THE NEED FOR EMISSION REDUCTIONS
Petitioners challenge both EPA’s conclusion that emission reductions are necessary to meet national air quality standards and the magnitude of the reduction said to be required. Their arguments can be divided into attacks on EPA’s data and methodology as to (1) photochemical oxidants in the Metropolitan Boston Intrastate Region; (2) carbon monoxide in the Boston core; (3) carbon monoxide at Logan Airport (East Boston).
1. EPA is said to have overestimated the photochemical oxidant problem in the Boston region. Most pertinent are petitioners’ arguments that the key ambient air quality reading taken on one day at a monitoring device located at Wellington Circle must have come from a defective instrument. This single reading, inserted by EPA in its so-called rollback formula (or “model”), was the basis for a region-wide estimate of the amount of hydrocarbon reduction required. If it was incorrect, so were the conclusions about how much reduction was necessary to achieve the primary standard. Petitioners point to a computer printout taken at that monitoring station; it contains a high number of “9999” readings which may indicate instrument malfunction. EPA’s response is that the designations may also result from “instrument calibration, instrument zeroing, transmissions loss and depletion of span gas, all of which causes are unrelated to any malfunction.” But petitioners contend that the irregular readings occurred too often to be attributable solely to innocent causes. On the present record, we cannot say with confidence that the use of a single reading from a machine as to which objective readings suggest a substantial possibility of malfunction is sufficient to support EPA’s photochemical oxidant determination.
We find less persuasive petitioners’ attack upon the accuracy of the rollback model itself because of its purported failure to take account of local topography and meteorology. EPA’s technical support document appears to consider these influences, and the only expert to stress Boston’s unique features did not include gasoline in his analysis. Petitioners further claim that EPA incorrectly related oxidant concentrations directly to emission of hydrocarbons, relying in part on an extra record document never brought to the Agency’s attention. Photochemical oxidants are a secondary pollutant derived from the reaction of two primary pollutants, hydrocarbons and nitrogen. To reduce oxidant concentrations, it is therefore necessary to control hydrocarbon emission and EPA has advanced plausible reasons for choosing the ratio that it did. See Texas v. EPA, supra, 499 F.2d at 306-308. Finally, petitioners object to the determination that regionwide controls, rather than controls in only a few heavily polluted sections, were necessary to bring oxidants down to a reasonable level. But background reports indicate that automobile use is heavy, particularly in the outlying manufacturing areas. The technical support document presents the view that the necessity for region-wide controls stems from the nature of the pollutant; petitioners’ contention that contrary conclusions can be drawn from the data does not lead us to suspect that EPA committed clear error. To the extent different conclusions could be drawn the Agency was entitled to draw its own.
2. Carbon monoxide data is attacked as unreliable. EPA determined that its national primary standard requiring the average amount of carbon monoxide in the air over an eight hour period,not to exceed 9 p. p. m. is not being met in the Boston core and will not be met by mid-1975. It did this by a series of calculations which have as their essential element an ambient air quality reading obtained on one day in 1970 from a monitor at Kenmore Square. Although petitioners attack use of the rollback model itself as unsophisticated, we are mainly impressed by the contention that the crucial figure for determining required emission reduction may be unrepresentative. At the time the plan was designed the next highest reading at Kenmore Square was nearly 50 percent lower than that utilized. EPA points to readings elsewhere even higher than that used in the rollback model, recorded after the plan was announced, as evidence that it may have “underestimated the extent of the CO problem". But petitioners claim these high readings are also freak events.
Petitioners also seek to discredit the Kenmore Square reading by pointing to EPA guidelines from which it may be inferred that the Kenmore monitor was located too close to the street curb. The guidelines do state that “for practical considerations it may not be feasible to select sampling sites that meet all of the specific and general guidelines”, and EPA asserts that use of the “Kenmore data is completely appropriate for Boston because in an older city like Boston, the streets are narrow, and many more people live and work close to heavily traveled roadways where they are exposed to high one-hour and eight-hour CO concentrations than in the case of newer cities designed with more open spaces like Phoenix, Houston, and even Washington, D.C.” But the guidelines warn that when there are deviations it is important that there also be comparisons with results from other stations; in 1970, the year the critical reading was recorded, Kenmore Square was the only operating monitoring site. Here again, on the present record, we have no basis to say with judicial conviction that such a slender base, without further justification, is sufficient to support EPA’s conclusion as to carbon monoxide in the Boston core.
3. In the best documented of the challenges to EPA technical data, South Terminal and Massport attack the carbon monoxide determinations at Logan Airport (East Boston). The preamble to the plan refers generally to the need to reduce pollution in East Boston, but the strictures fall on Logan Airport, the only part of East Boston to be controlled. The Administrator concluded that the “carbon monoxide problem is concentrated in two relatively small areas — Logan Airport and the Boston core area.” 38 Fed.Reg. 20961 (1973). He also stated that the “overwhelming majority of the vehicle miles of travel in East Boston is generated by a single source: Logan International Airport. Consequently, transportation control strategies aimed at reducing VMT generated by Logan Airport are necessary for attaining the carbon monoxide standard in that portion of Boston.” Id. Massport, the operator of Logan, complained after the official period for comment had expired, but before the plan was published in the Federal Register, that no air quality monitoring had been performed at Logan to substantiate that the 8 hour carbon monoxide standard was exceeded there. South Terminal had earlier complained that what it considered more stringent controls on Logan than elsewhere were not justified by any technical data. In the preamble to the final plan, responding to the public comments it had received, EPA answered Massport’s criticism by referring to a report which had concluded that 8 percent of the carbon monoxide readings on-airport exceeded EPA’s primary standard and 6 percent of the off-airport readings exceeded standards. 38 Fed.Reg. 30963 (1973). However, this study used “grab sample” spot readings, not EPA’s suggested method for the determination and sampling of carbon monoxide, 40 C.F.R. § 50.8, Appendix C.
More significantly, Massport has had the record supplemented with the results of its own testing at a Logan site which EPA has conceded “meets the criteria for the eight hour standard”. These data show that carbon monoxide levels at Logan are strikingly lower than at other Boston sites and that the federal primary eight hour air quality standard has never been exceeded. To counter the submission of this data, EPA points to a report in the record that a maximum 8 hour concentration of 19 p. p. m. was recorded at Logan and that in a six day period the primary air quality standard was exceeded on five days. The report also concluded that the concentrations of carbon monoxide at Logan were roughly equivalent to those measured elsewhere in the metropolitan Boston region. However, the author of the study expressed doubts whether it was accurately reporting on “ambient air” as that term is defined in 40 C.F.R. § 50.-1(e). Moreover, it was published after the plan was announced and interested parties have not had an opportunity to criticize the findings. We conclude that it is not yet clear whether or not the ambient air at Logan meets, or will without controls by mid-1975 meet, the national primary standard.
Logan might have lower pollutant levels than those recorded outside its boundaries in East Boston, but nonetheless be responsible for excess levels of carbon monoxide in East Boston. If so, it would not be arbitrary for EPA to force reductions in vehicle miles traveled to the airport. But the record does not sufficiently demonstrate the degree to which East Boston’s air is affected by Logan traffic. The same Kenmore Square air quality figure, inserted in the rollback formula, was used to project the required reduction in East Boston; there was no actual monitoring anywhere in East Boston. South Terminal claims that Kenmore data should not be the basis for air quality predictions near Logan given the jetport’s unique configuration and air patterns as contrasted with those of the Boston core. EPA record materials suggest that the rollback formula is most reliable when applied in areas having similar characteristics. Moreover, the traffic generated by Logan utilizes main arteries, not local East Boston streets. A report in the record indicates that 80 percent of the traffic enters and leaves the airport via Route US-1 North and South. The record does not indicate whether people work or live sufficiently close to the tunnel connecting Boston and East Boston or to Route 1 to justify controlling this traffic. The primary air quality standard applies only to ambient air— “that portion of the atmosphere, external to buildings, to which the general public has access”. 40 C.F.R. § 50.1(e). The special qualities of carbon monoxide, as compared to photo-chemical oxidants, make the absence of such data critical to any argument that Logan traffic should be controlled to protect East Boston. The EPA engineer states that “carbon monoxide is a highly localized pollutant which tends to stay fairly close to where it was emitted,” and a report in the record indicates that “due to the localized nature of the problem, carbon monoxide concentrations need to be controlled within areas of blocks, not entire regions”.
The method of sampling at Logan, Massport’s own testing, and the lack of monitoring in East Boston, collectively, on the present record, prevent us from holding that the data is sufficient to support EPA’s conclusion as to carbon monoxide in East Boston.
4. While for reasons stated in items (1), (2), and (3), swpra, we are unable at this time to uphold EPA’s conclusions as to photochemical oxidant and carbon monoxide levels and reductions, we do not say that they are necessarily incorrect. Petitioners forcefully contend that the Agency’s measurements are without reliable foundation, and hence, in effect, arbitrary and capricious. See Section I supra. But as laymen we are in no position to know how much ultimate weight to give to these arguments, based as they are on technical assumptions. We can only say that the objections as to data and methodology seem too serious to us simply to pass by; they demand investigation and answer. While reviewing courts are not to substitute their judgment for an agency’s, they are to establish parameters of rationality within which the agency must operate. A court would abdicate its function were it, when confronted with important and seemingly plausible objections going to the heart of a key technical determination, to presume that the agency could never behave irrationally. It has a duty to see that the objections are faced in a proper procedural setting and satisfactory answers provided demonstrating careful agency consideration.
The normal way courts evaluate a technical issue is through proceedings attended by expert witnesses. Yet as an appellate court, we cannot conduct such fact-finding proceedings on our own. Congress has not interposed a district court in the chain of review, so we cannot remand for clarifying findings of fact based, perhaps, on testimony by Agency and private experts. Cf. Camp v. Pitts, 411 U.S. 138, 142-143, 93 S.Ct. 1241, 36 L.Ed.2d 106 (1972). We are left — when confronted with objections which, on the one hand, seriously call into question the rationality of Agency action, but on the other require expertise to resolve — no alternative but to remand the matter to the Agency itself. In many circumstances such a limited remand could be for a unilatreal “explanation” or “clarification” of the Agency’s views. See, e. g., Natural Resources Defense Counsel, Inc. v. EPA, 478 F.2d 875, 881-882 (1st Cir. 1973); Kennecott Copper Corp. v. EPA, 149 U.S.App.D.C. 231, 462 F.2d 846, 848-851 (1972). See also Overton Park, supra, 401 U.S. at 420-421, 91 S.Ct. 814, 28 L.Ed.2d 136. If the adequacy of the Agency’s measurement had been raised at the hearing, then such a remand-for-explanation might be sufficient. But when the question is one which the Agency may never have fully confronted and which may deserve further input both from Agency and outside sources, only a remand for further hearings and an extended record seems adequate. Cf. Portland Cement Ass’n v. Ruckelshaus, 158 U.S.App.D.C. 308, 486 F.2d 375, 393-394 (1973), cert. denied, 417 U.S. 921, 94 S.Ct. 2628, 41 L.Ed.2d 226 (1974). EPA should be in a position to hear the same arguments presented to us in a setting conducive to the exchange of ideas and data. If, after resolution of the issue by the Agency, the issue is returned to us, we will be able to rule expeditiously on the rationality of the Agency’s measurements with assurance that EPA-has fully confronted the objections and that its explication is more than a post hoc rationalization.
It is perhaps paradoxical that the necessity of a further hearing

Question: What is the specific issue in the case within the general category of "economic activity and regulation"?
A. taxes, patents, copyright
B. torts
C. commercial disputes
D. bankruptcy, antitrust, securities
E. misc economic regulation and benefits
F. property disputes
G. other
Answer:

Answer: E