proceedings to a trial examiner to determine if the certificate should be granted under the "public convenience and necessity" standard of § 7. The Court of Appeals' reversal of the District Court 10 on the curtailment issue rested on its view that under the Natural Gas Act ". . . FPC has no form of continuing certificate jurisdiction over direct sales to customers of interstate pipeline companies. It has the initial right to issue or veto a certificate of public convenience and necessity and it must give its approval to the abandonment of the use of the certificated facilities, but between the two functions the express exemption [in the proviso of § 1 (b)] of regulatory power over such consumptive sales bars agency intervention." 456 F. 2d, at 338. The Court of Appeals' holding that United's injection of interstate gas from its Black System into the theretofore intrastate Green System did not establish FPC jurisdiction to certificate the Green System, rested on its finding that the record showed that "the flow of gas from the Black system into the Green system in the case at bar is occasional and irregular, as well as minimal. The Green system, as an entire and separate unit, is physically located and functions entirely in Louisiana. Therefore, the undisputed facts show that the channel of constant flow is an intrastate and not an interstate channel. The regulation of the Green system is substantially and essentially a localized matter committed to Louisiana's jurisdiction." 456 F. 2d, at 339-340. 10 Argument was heard in the Fifth Circuit in November 1971, one month after the FPC decision in No. 606. The Court of Appeals decision was announced in January 1972, one month before the FPC decision in No. 610. 621 Opinion of the Court III The Natural Gas Act of 1938 granted FPC broad powers "to protect consumers against exploitation at the hands of natural gas companies." FPC v. Hope Natural Gas Co., 320 U. S. 591, 610 (1944). See FPC v. Transcontinental Gas Pipe Line Corp., 365 U. S. 1, 19 (1961); Sunray Mid-Continent Oil Co. v. FPC, 364 U. S. 137, 147 (1960). To that end, Congress "meant to create a comprehensive and effective regulatory scheme," Panhandle Eastern Pipe Line Co. v. Public Service Comm'n, 332 U. S. 507, 520 (1947), of dual state and federal authority. Although federal jurisdiction was not to be exclusive, FPC regulation was to be broadly complementary to that reserved to the States, so that there would be no "gaps" for private interests to subvert the public welfare. This congressional blueprint has guided judicial interpretation of the broad language defining FPC jurisdiction, and "when a dispute arises over whether a given transaction is within the scope of federal or state regulatory authority, we are not inclined to approach the problem negatively, thus raising the possibility that a 'no man's land' will be created. Compare Guss v. Utah Labor Board, 353 U. S. 1. That is to say, in a borderline case where congressional authority is not explicit we must ask whether state authority can practicably regulate a given area and, if we find that it cannot, then we are impelled to decide that federal authority governs." FPC v. Transcontinental Gas Pipe Line Corp., supra, at 19-20. This litigation poses the question whether FPC has authority to effect orderly curtailment plans involving both direct sales and sales for resale. LP&L insists that Opinion of the Court 406 U.S. the FPC has no power to include direct sales in these plans. Transcontinental counsels inquiry into the necessary consequences of that contention in terms of the scope of federal and state regulatory authority in the premises. Thirty-seven percent of United's total sales in 1970 were direct industrial sales. Under LP&L's argument, this volume would be wholly exempt from any curtailment plan approved by the FPC and thus United's resale customers would be forced to accept the entire burden of sharply reduced volumes while direct-sales customers received full contract service. The ultimate consumers thus affected include schools, hospitals, and homes completely dependent on a continued natural gas supply for heating and other domestic uses. These resale consumers could be curtailed by as much as 560,000 Mcf on cold days without dire consequences, but burdening them with the full curtailment volume would deprive them of up to 1,500,000 Mcf. From a practical point of view, LP&L's position may thus produce a seriously inequitable system of gas distribution. Many direct industrial users of gas require only "interruptible services," which by the terms of their contracts are recognized to be of such minimal importance to the user that, upon the happening of certain events, the supply can be shut off on little or no notice. Nevertheless, the need for curtailment may not be sufficient to trigger these provisions of the contract and interruptible service customers may be able to demand full contract gas while resale consumers are being drastically curtailed. Many other direct industrial sales customers have alternative means available at little or no additional cost, yet under LP&L's contention will be able to demand their contract volumes while homes, hospitals, and schools suffer from lack of adequate service. Can state authority practicably regulate in this area to prevent this inequity and hardship? Insofar as state 621 Opinion of the Court plans purport to curtail deliveries of interstate gas, Pennsylvania v. West Virginia, 262 U. S. 553 (1923), is authority that such plans, when they operate to withdraw a large volume of gas from an established interstate current whereby it is supplied to customers in other States, would constitute a prohibited interference with interstate commerce. But even to the extent the States may constitutionally promulgate curtailment plans, the inevitable result would be varied regulatory programs of state courts and agencies, interpreting a countless number of different contracts and applying a variety of state agency rules. The conflicting results would necessarily produce allocations determined simply by the ability of each customer to pump its desired volume from a pipeline. Moreover, in some States, Louisiana for example, the state regulatory agency is forbidden to regulate direct-sales contracts." Besides, a state agency empowered to regulate these contracts would be obliged to regulate in the State, not the national interest. Cf. Pennsylvania v. West Virginia, supra. The unavoidable conflict between producing 12 11 La. Const., Art. 6, § 4. 12 The conflict between producing and consuming States over state or federal regulatory authority is highlighted in the contrast between Louisiana's amicus brief in this litigation and the statement of the Chairman of the New York Public Service Commission in another case. Louisiana, a producing State, submits: "Historically, gas producing states have certain advantages over states which do not have their own gas supply. Their very proximity to the source of production attracts industries which use gas as the raw material without which their plants could not operate. The lower transportation costs of delivering gas to other industrial and commercial users within the state makes its use particularly attractive for such applications. It is not surprising, therefore, that producing states have a higher proportion of industrial-commercial consumption of total gas consumed and of firm gas than consuming states. Louisiana utilizes 84% of the total quantity of firm gas sold Opinion of the Court 406 U.S. States and consuming States will create contradictory regulations that cannot possibly be equitably resolved by the courts. With these problems in mind, the de in the state for industrial and power plant generation purposes, in comparison to a national average of only 37%. "Louisiana's economy is heavily dependent upon the availability of a firm, reliable and uninterrupted supply of natural gas. Statewide investment by industrial category clearly reflects the predominance of petroleum, refineries and chemicals which represented $465,297,370 or 76% of a total industrial investment of $609,578,850 in 1970. Apart from these industries which use natural gas as process gas without which their plants cannot function, the state's electric utilities are completely dependent upon natural gas as fuel for electric generators. "Thus, the economic welfare of the state hinges upon the continued delivery of the volumes of gas it received and used prior to United's curtailment and upon the ability to draw upon greater volumes. Otherwise, its economy will be frozen at or below its present level. This is not true of other states in which natural gas plays a subsidiary rather than a dominant role in the overall economy of the state and in which the electrical utilities have alternate power sources such as coal, imported liquefied natural gas and inexpensive hydroelectric power." Brief of State of Louisiana Amicus Curiae 2-3. As observed in FPC v. Transcontinental Gas Pipe Line Corp., 365 U. S. 1 (1961), consuming States prefer federal regulation. The Chairman of the New York Public Service Commission summed up this position in In re Cabot Gas Corp., 16 P. U. R. (N. S.) 443 (1936): "There can be but one opinion among those who believe in the conservation of natural resources. They should be developed not to benefit a few individuals but in the interests of public welfare present and future. Our natural gas resources ought to be conserved and there is probably no field where the Federal government acting in the interests of the entire country and to protect the welfare of the future could accomplish more than in the natural gas industry. From a conservation viewpoint, I thoroughly agree with Commissioner Burritt, and if I could see how a denial of the present petition. would work to this end, I would vote to refuse the application; but will such denial produce the desired results? "The field from which gas is to be taken by the petitioner is in |