should have the capacity to determine those levels of control which can be achieved for nuclear fuels processing plants. If they do not, such a capability should be developed and this particular source should be added to the list of new sources as soon as possible." Ibid.

Petitioners assert that this statement by the Committee has no bearing on the question before the Court. The statement, petitioners suggest, reflects no more than a recognition, shared by them, that the plants referred to were not intended to be wholly excluded from the reach of the FWPCA-a recognition that in their view means that the EPA can control the discharge from such plants of polluting materials other than source, byproduct, and special nuclear materials. In short, petitioners contend that the statement sheds no light on the question whether source, byproduct, and special nuclear materials are pollutants under the FWPCA.

We agree with the petitioners that the Senate Committee statement is addressed to the inclusion of nuclear fuels processing plants in the category of sources subject to the EPA's control, not to the inclusion of any particular materials within the definition of "pollutant." It is true that the reference to the development of control levels by the Bureau of Radiological Health " does permit the inference that the Committee was contemplating controls over the discharge of AEA-regulated radioactive materials. Still, we are not prepared to attribute greater significance to this inference than to the more explicit statement contained in the House Committee Report, a statement that, as we shall see, is amply

11 The Bureau of Radiological Health was transferred to the EPA from the Department of Health, Education, and Welfare pursuant to §2 (a) (3) (ii) (C) of Reorganization Plan No. 3 of 1970, which established the EPA. 84 Stat. 2087, 5 U. S. C. App., p. 610.

supported by the discussion on the floors of the House and the Senate.

A colloquy on the Senate floor between Senator Pastore, the Chairman of the Joint Committee on Atomic Energy, and Senator Muskie, the FWPCA's primary author, provides a strong indication that Congress did not intend the FWPCA to alter the AEC's control over the discharge of source, byproduct, and special nuclear materials. Senator Pastore, referring to the need to define what materials are "subject to control requirements" under the FWPCA, noted that the definition of "pollutant" included the words "radioactive materials." 2 Leg. Hist. 1265. The following exchange then took place:

"My question is this: Does this measure that has been reported by the committee in any way affect the existing law, that is, the existing Atomic Energy Act of 1954, insofar as the regulatory powers of the AEC are concerned with reference to radioactive material?

"MR. MUSKIE. It does not; and it is not the intent of this act to affect the 1954 legislation.

"MR. PASTORE. In other words, this bill does not change that feature of the Atomic Energy Act in any regard?

"MR. MUSKIE. That is correct.

"MR. PASTORE. I thank the Senator.

"MR. MUSKIE. May I say in addition, that legislation dealing with the setting of effluent limitations as they involve nuclear powerplants is now pending in the courts. The Senator is aware of that litigation.

"For example, a recent decision of the U. S. Court

of Appeals for the Eighth Circuit, in the case of Northern States Power and Light versus Minnesota, raises the issue. I would like to point out that the committee considered speaking specifically to that decision, but chose to remain silent so as not to prejudice the decision or any appeal from it.

"MR. PASTORE. Yes. As a matter of fact, that decision held that the Federal Government did preempt in this field under existing law. That is the opinion, and we hope this legislation does not change that opinion in any way, and does not affect existing law. That is all I am concerned with.

"MR. MUSKIE. The Senator is correct in his evaluation of the legislation on that point." Id., at 1265-1266.

Respondents contend that this colloquy "merely reiterates that the FWPCA does not alter the regulatory authority of the AEC" over source, byproduct, and special nuclear materials. Brief for Respondents 40-41. The exchange, they assert, says nothing about the EPA's authority to regulate the same materials. The discussion is consistent, they claim, with their position that the AEC must defer to the EPA in the setting of effluent limitations for AEA-regulated materials-that, for example, NRC licenses must conform to permits issued under the FWPCA. We disagree.

The thrust of Senator Muskie's assurances that the FWPCA would not "in any way affect" the regulatory powers of the AEC was, we think, that the AEC was to retain full authority to regulate the materials covered by the AEA, unaltered by the exercise of regulatory authority by any agency under the FWPCA. This conclusion is reinforced by Senator Muskie's reference to the case of Northern States Power Co. v. Minnesota, 447 F.2d 1143 (CA8 1971). In that case, which was subse

12

quently affirmed summarily by this Court, 405 U. S. 1035 (1972), the Eighth Circuit had held that the AEA created a pervasive regulatory scheme, vesting exclusive authority to regulate the discharge of radioactive effluents from nuclear power plants in the AEC, and pre-empting the States from regulating such discharges. The absence of any room for a state role under the AEA in setting limits on radioactive discharges from nuclear power plants stands in sharp contrast to the scheme created by the FWPCA, which envisions the development of state permit programs, 33 U. S. C. §§ 1342 (b), (c) (1970 ed., Supp. IV), and allows the States to adopt effluent limitations more stringent than those required or established under the FWPCA. 33 U. S. C. § 1370 (1970 ed., Supp. IV). See also 33 U. S. C. §§ 1311 (b)(1)(C), 1314 (b), 1316 (c), 1341 (a) (1) (1970 ed., Supp. IV). Senator

13

12 The AEA, as amended in 1959, 73 Stat. 688, 42 U. S. C. § 2021, does permit the States to assume, pursuant to agreements with the AEC, a limited role in regulating source and byproduct materials, and special nuclear materials in quantities not sufficient to form a critical mass. But state regulatory programs must be compatible wth the AEC's regulatory program, § 2021 (d)(2), and States are precluded from playing any role in several significant areas of regulation-including the setting of limitations on radioactive discharges from nuclear power plants. § 2021 (c) (1); Northern States Power Co. v. Minnesota, 447 F: 2d 1143, 1149 n. 6 (CA8 1971).

13 Section 101 (b) of the FWPCA, 33 U. S. C. § 1251 (b) (1970 ed., Supp. IV), provides generally:

"It is the policy of the Congress to recognize, preserve, and protect the primary responsibilities and rights of States to prevent, reduce, and eliminate pollution, to plan the development and use (including restoration, preservation, and enhancement) of land and water resources, and to consult with the Administrator in the exercise of his authority under this chapter. It is further the policy of the Congress to support and aid research relating to the prevention, reduction, and elimination of pollution and to provide Federal technical services and financial aid to State and interstate

1

Opinion of the Court

Muskie's specific assurance to Senator Pastore that the FWPCA would not affect existing law as interpreted in Northern States can only be viewed, we think, as an indication that the exclusive regulatory scheme created by the AEA for source, byproduct, and special nuclear materials was to remain unaltered.11

In the course of the House's consideration of the FWPCA, an unsuccessful attempt was made to alter the AEA's scheme for regulating the discharge of the radioactive materials involved in this case. Representative Wolff proposed to amend what is now 33 U. S. C. § 1370 (1970 ed., Supp. IV), which gives States the authority to set more stringent limits on the discharge of pollutants, by adding a paragraph giving the States the authority to regulate the discharge of radioactive wastes from nuclear power plants. The debate on that amendment and its defeat by a 3-to-1 vote provide solid

agencies and municipalities in connection with the prevention, reduction, and elimination of pollution."

14 Respondents contend that a discussion between Senator Buckley and Senator Muskie on the Senate floor is indicative of an intent to permit the EPA to regulate the discharge of AEA-regulated radioactive materials. Senator Buckley expressed concern about § 511 (c) (2) (B) of the FWPCA, 33 U. S. C. § 1371 (c)(2)(B) (1970 ed., Supp. IV), which precludes agencies other than EPA from "impos[ing], as a condition precedent to the issuance of any license or permit, any effluent limitation other than any such limitation established pursuant to this chapter." Referring to recent action by the AEC to control thermal pollution of the Hudson River, Senator Buckley asked Senator Muskie whether § 511 (c) (2) (B) would bar AEC decisions "of this type" setting tougher limitations than those prescribed by the EPA. Senator Muskie's response was that the AEC would be required to abide by EPA effluent limitation controls "with respect to the subject matter which the Senator has raised." 1 Leg. Hist. 198. The subject matter raised was thermal pollution, and we do not interpret Senator Muskie's response as suggesting that a similar conclusion would be reached with respect to pollution by AEA-regulated radioactive materials.