The issue in this case is whether operating a dam to produce hydroelectricity "may result in any discharge into the navigable waters" of the United States. If so, a federal license under § 401 of the Clean Water Act requires state certification that water protection laws will not be violated. We hold that a dam does raise a potential for a discharge, and state approval is needed.
The Presumpscot River runs through southern Maine from Sebago Lake to Casco Bay, and in the course of its 25 miles petitioner, S. D. Warren Company, operates several hydropower dams to generate electricity for its paper mill. Each dam creates a pond, from which water funnels into a "power canal," through turbines, and back to the riverbed, passing around a section of the river just below the impoundment.
It is undisputed that since 1935, Warren has needed a license to operate the dams, currently within the authority of the Federal Energy Regulatory Commission (FERC) under the Federal Power Act. 16 U. S. C. §§ 817(1), 792; see also Public Utility Act of 1935, § 210, 49 Stat. 846. FERC grants these licenses for periods up to 50 years, 16 U. S. C. § 799,
Over 30 years ago, Congress enacted a specific provision for licensing an activity that could cause a "discharge" into navigable waters; a license is conditioned on a certification from the State in which the discharge may originate that it will not violate certain water quality standards, including those set by the State's own laws. See Water Quality Improvement Act of 1970, § 103, 84 Stat. 108. Today, this requirement can be found in § 401 of the Clean Water Act, 86 Stat. 877, 33 U. S. C. § 1341: "Any applicant for a Federal license or permit to conduct any activity . . . which may result in any discharge into the navigable water[s] shall provide the licensing or permitting agency a certification from the State in which the discharge originates . . . ." § 1341(a)(1).
In 1999, Warren sought to renew federal licenses for five of its hydroelectric dams. It applied for water quality certifications from the Maine Department of Environmental Protection
The Maine agency issued certifications that required Warren to maintain a minimum stream flow in the bypassed portions of the river and to allow passage for various migratory fish and eels. When FERC eventually licensed the five dams, it did so subject to the Maine conditions, and Warren continued to deny any need of § 401 state certification. After appealing unsuccessfully to Maine's administrative appeals tribunal, the Board of Environmental Protection, Warren filed this suit in the State's Cumberland County Superior Court. That court rejected Warren's argument that its dams do not result in discharges, and the Supreme Judicial Court of Maine affirmed. 2005 ME 27, 868 A.2d 210. We granted certiorari, 546 U.S. 933 (2005), and now affirm as well.
The dispute turns on the meaning of the word "discharge," the key to the state certification requirement under § 401.
When it applies to water, "discharge" commonly means a "flowing or issuing out," Webster's New International Dictionary 742 (2d ed. 1954); see also ibid. ("[t]o emit; to give outlet to; to pour forth; as, the Hudson discharges its waters into the bay"), and this ordinary sense has consistently been the meaning intended when this Court has used the term in prior water cases. See, e. g., Marsh v. Oregon Natural Resources Council, 490 U.S. 360, 364 (1989) (describing a dam's "`multiport' structure, which will permit discharge of water from any of five levels"); Arizona v. California, 373 U.S. 546, 619, n. 25 (1963) (Harlan, J., dissenting in part) (quoting congressional testimony regarding those who "`take . . . water out of the stream which has been discharged from the reservoir'"); United States v. Arizona, 295 U.S. 174, 181 (1935) ("Parker Dam will intercept waters discharged at Boulder Dam").
In fact, this understanding of the word "discharge" was accepted by all Members of the Court sitting in our only other case focused on § 401 of the Clean Water Act, PUD No. 1 of Jefferson Cty. v. Washington Dept. of Ecology, 511 U.S. 700 (1994). At issue in PUD No. 1 was the State of Washington's authority to impose minimum stream flow rates on a hydroelectric dam, and in posing the question presented, the Court said this:
The Pud No. 1 petitioners claimed that a state condition imposing a stream flow requirement on discharges of water from a dam exceeded the State's § 401 authority to prevent degradation of water quality, but neither the parties nor the Court questioned that the "discharge of water" from the dam was a discharge within the ambit of § 401. Ibid. And although the Court's opinion made no mention of the dam as adding anything to the water, the majority's use of the phrase "discharge of water" drew no criticism from the dissent, which specifically noted that "[t]he term `discharge' is not defined in the [Clean Water Act] but its plain and ordinary meaning suggests `a flowing or issuing out,' or `something that is emitted.'" Id., at 725 (opinion of Thomas, J.) (quoting Webster's Ninth New Collegiate Dictionary 360 (1991)).
In resort to common usage under § 401, this Court has not been alone, for the Environmental Protection Agency (EPA) and FERC have each regularly read "discharge" as having its plain meaning and thus covering releases from hydroelectric dams. See, e. g., EPA, Water Quality Standards Handbook § 7.6.3, p. 7-10 (2d ed. 1994) ("EPA has identified five Federal permits and/or licenses that authorize activities that may result in a discharge to the waters[, including] licenses required for hydroelectric projects issued under the Federal Power Act"); FPL Energy Maine Hydro LLC, 111 FERC ¶ 61,104, p. 61,505 (2005) (rejecting, in a recent adjudication, the argument that Congress "used the term `discharge' as nothing more than a shorthand expression for `discharge of a pollutant or pollutants'").
Warren makes three principal arguments for reading the term "discharge" differently from the ordinary way. We find none availing.
The first involves an interpretive canon we think is out of place here. The canon, noscitur a sociis, reminds us that "a word is known by the company it keeps," Gustafson v. Alloyd Co., 513 U.S. 561, 575 (1995), and is invoked when a string of statutory terms raises the implication that the "words grouped in a list should be given related meaning," Dole v. Steelworkers, 494 U.S. 26, 36 (1990) (internal quotation marks omitted); see also Beecham v. United States, 511 U.S. 368, 371 (1994) ("That several items in a list share an attribute counsels in favor of interpreting the other items as possessing that attribute as well").
The problem with Warren's argument is that it purports to extrapolate a common feature from what amounts to a single item (discharge of a pollutant plus the plural variant involving more than one pollutant). See Beecham, supra, at 371. The argument seems to assume that pairing a broad statutory term with a narrow one shrinks the broad one, but there is no such general usage; giving one example does not convert express inclusion into restrictive equation, and noscitur a sociis is no help absent some sort of gathering with
Regardless, Warren says the statute should, and even must, be read its way, on the authority of South Fla. Water Management Dist. v. Miccosukee Tribe, 541 U.S. 95 (2004). But that case is not on point. Miccosukee addressed § 402 of the Clean Water Act, not § 401, and the two sections are not interchangeable, as they serve different purposes and use different language to reach them. Section 401 recast pre-existing law and was meant to "continu[e] the authority of the State . . . to act to deny a permit and thereby prevent a Federal license or permit from issuing to a discharge source within such State." S. Rep. No. 92-414, p. 69 (1971). Its terms have a broad reach, requiring state approval any time a federally licensed activity "may" result in a discharge ("discharge" of course being without any qualifiers here), 33 U. S. C. § 1341(a)(1), and its object comprehends maintaining state water quality standards, see n. 1, supra.
Section 402 has a historical parallel with § 401, for the legislative record suggests that it, too, was enacted to consolidate and ease the administration of some predecessor regulatory schemes, see H. R. Rep. No. 92-911, at 124-125. But it contrasts with § 401 in its more specific focus. It establishes what Congress called the National Pollutant Discharge Elimination System, requiring a permit for the "discharge of any pollutant" into the navigable waters of the United States, 33 U. S. C. § 1342(a). The triggering statutory
The question in Miccosukee was whether a pump between a canal and an impoundment produced a "discharge of a pollutant" within the meaning of § 402, see 541 U. S., at 102-103, and the Court accepted the shared view of the parties that if two identified volumes of water are "simply two parts of the same water body, pumping water from one into the other cannot constitute an `addition' of pollutants," id., at 109. Miccosukee was thus concerned only with whether an "addition" had been made (phosphorous being the substance in issue) as required by the definition of the phrase "discharge of a pollutant"; it did not matter under § 402 whether pumping the water produced a discharge without any addition. In sum, the understanding that something must be added in order to implicate § 402 does not explain what suffices for a discharge under § 401.
Warren's third argument for avoiding the common meaning of "discharge" relies on the Act's legislative history, but we think that if the history means anything it actually goes against Warren's position. Warren suggests that the word "includes" in the definition of "discharge" should not be read with any spacious connotation, because the word was simply left on the books inadvertently after a failed attempt to deal specifically with "thermal discharges." As Warren describes it, several Members of Congress recognized that "heat is not as harmful as what most of us view as `pollutants,' because it dissipates quickly in most bodies of receiving waters," 1 Legislative History of the Water Pollution Control Act Amendments of 1972 (Committee Print compiled for the Senate Committee on Public Works by the Library of Congress), Ser. No. 93-1, p. 273 (1973) (remarks of Rep. Clark), and they proposed to regulate thermal discharges less stringently than others. They offered an amendment to exclude thermal discharges from the requirements under § 402, but they also wanted to ensure that thermal discharges remained within the scope of § 401 and so sought to include them expressly in the general provision covering "discharge." See id., at 1069-1070, 1071. The proposed definition read, "[t]he term `discharge' when used without qualification includes a discharge of a pollutant, a discharge of pollutants, and a thermal discharge." Id., at 1071.
Of course, Congress omitted the reference to "thermal discharge," and settled on the definition we have today. See Federal Water Pollution Control Act Amendments of 1972, § 502(16), 86 Stat. 887. Warren reasons that once Congress abandoned the special treatment for thermal pollutants, it merely struck the words "thermal discharge" from 33 U. S. C. § 1362(16) and carelessly left in the word "includes."
This is what might be called a lawyer's argument. We will assume that Warren is entirely correct about the impetus behind the failed attempt to rework the scope of pollutant discharge under § 402. It is simply speculation, though, to say that the word "includes" was left in the description of a "discharge" by mere inattention, and for reasons given in Part IV of this opinion it is implausible speculation at that. But if we confine our view for a moment strictly to the drafting history, the one thing clear is that if Congress had left "thermal discharge" as an included subclass of a "discharge" under § 502(16), Warren would have a stronger noscitur a sociis argument. For a thermal discharge adds something, the pollutant heat, see n. 3, supra. Had the list of examples of discharge been lengthened to include thermal discharges, there would have been at least a short series with the common feature of addition. As it stands, however, the only thing the legislative history cited by Warren demonstrates is the congressional rejection of language that would have created a short series of terms with a common implication of an addition.
Warren's theory, moreover, has the unintended consequence of underscoring that Congress probably distinguished the terms "discharge" and "discharge of pollutants" deliberately, in order to use them in separate places and to separate ends. Warren hypothesizes that Congress attempted to tinker with the definition of "discharge" because it wanted to subject thermal discharges to the requirements of § 401, but not § 402. But this assumption about Congress's
Warren's arguments against reading the word "discharge" in its common sense fail on their own terms.
The alteration of water quality as thus defined is a risk inherent in limiting river flow and releasing water through turbines. Warren itself admits that its dams "can cause changes in the movement, flow, and circulation of a river . . . caus[ing] a river to absorb less oxygen and to be less passable by boaters and fish." Brief for Petitioner 23. And several amici alert us to the chemical modification caused by the dams, with "immediate impact on aquatic organisms, which of course rely on dissolved oxygen in water to breathe." Brief for Trout Unlimited et al. as Amici Curiae 13; see also, e. g., Brief for National Wildlife Federation et al. as Amici Curiae 6 (explaining that when air and water mix in a turbine, nitrogen dissolves in the water and can be potentially lethal to fish). Then there are the findings of the Maine Department of Environmental Protection that led to this appeal:
Changes in the river like these fall within a State's legitimate legislative business, and the Clean Water Act provides for a system that respects the States' concerns. See 33 U. S. C. § 1251(b) ("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"); § 1256(a) (federal funds for state efforts to prevent pollution); see also § 1370 (States may impose standards on the discharge of pollutants that are stricter than federal ones).
State certifications under § 401 are essential in the scheme to preserve state authority to address the broad range of pollution, as Senator Muskie explained on the floor when what is now § 401 was first proposed:
These are the very reasons that Congress provided the States with power to enforce "any other appropriate requirement of State law," 33 U. S. C. § 1341(d), by imposing conditions on federal licenses for activities that may result in a discharge, ibid.
It is so ordered.
Briefs of amici curiae urging affirmance were filed for the State of New York et al. by Eliot Spitzer, Attorney General of New York, Caitlin J. Halligan, Solicitor General, Robert H. Easton, Deputy Solicitor General, Peter H. Lehner, Gregory Silbert, Assistant Solicitor General, and James M. Tierney, Assistant Attorney General, by Rob McKenna, Attorney General of Washington, and Brian Faller and Ron Lavigne, Assistant Attorneys General, by Roberto J. Sánchez Ramos, Secretary of Justice of Puerto Rico, by Susan Shinkman, and by the Attorneys General for their respective States as follows: David W. Márquez of Alaska, Terry Goddard of Arizona, Bill Lockyer of California, Richard Blumenthal of Connecticut, Carl C. Danberg of Delaware, Mark J. Bennett of Hawaii, Lisa Madigan of Illinois, Thomas J. Miller of Iowa, Gregory D. Stumbo of Kentucky, Charles C. Foti, Jr., of Louisiana, J. Joseph Curran, Jr., of Maryland, Thomas F. Reilly of Massachusetts, Michael A. Cox of Michigan, Mike Hatch of Minnesota, Jeremiah W. (Jay) Nixon of Missouri, Mike McGrath of Montana, George J. Chanos of Nevada, Kelly A. Ayotte of New Hampshire, Peter C. Harvey of New Jersey, Patricia A. Madrid of New Mexico, Roy Cooper of North Carolina, W. A. Drew Edmondson of Oklahoma, Hardy Myers of Oregon, Patrick C. Lynch of Rhode Island, Henry Mc-Master of South Carolina, Lawrence E. Long of South Dakota, Paul G. Summers of Tennessee, Mark L. Shurtleff of Utah, William H. Sorrell of Vermont, Darrell V. McGraw, Jr., of West Virginia, and Peggy S. Lautenschlager of Wisconsin; for Friends of the Everglades by John E. Childe; for Former Assistant Administrators of the United States Environmental Protection Agency by Robert G. Dreher, Jennifer Chavez, and Howard I. Fox; for the Hoopa Valley Tribe et al. by Thomas P. Schlosser, Carl Ullman, and Daniel A. Raas; for the Miccosukee Tribe of Indians of Florida by Dexter W. Lehtinen, Claudio Riedi, Sonia Escobio O'Donnell, and Enrique D. Arana; the National Wildlife Federation et al. by David K. Mears; for Trout Unlimited et al. by James B. Dougherty; for Water Quality and Riverine Scientists by Richard Roos-Collins and Steven P. Malloch; and for Senator James M. Jeffords by Mr. Jeffords, pro se.
Benjamin S. Sharp, Guy R. Martin, and Karen M. McGaffey filed a brief for the Western Urban Water Coalition as amicus curiae.
Likewise, we are not persuaded by Warren's claim that the word "into" somehow changes the meaning of the word "discharge" so as to require an addition. See Reply Brief for Petitioner 1-2 ("However one might read the lone word `discharge' by itself, the complete statutory phrase `discharge into the navigable waters' entails the introduction of something into the waters"). The force of this argument escapes us, since one can easily refer to water being poured or discharged out of one place into another without implying that an addition of some hitherto unencountered mixture or quality of water is made. Indeed, the preposition "into" was used without connoting an addition in the Miccosukee analogy cited by Warren. See 541 U. S., at 110 ("[I]f one takes a ladle of soup from a pot . . . and pours it back into the pot, one has not `added' soup or anything else to the pot" (internal quotation marks and brackets omitted)).
But Warren overlooks the fact that "discharge of a pollutant" is used in § 511(c)(2) in the course of identifying the agency, not the activity to be certified. Whether a § 401 certification involves an activity that discharges pollutants or one that simply discharges, FERC (as an agency that may be described, always, as one with "author[ity] to license or permit the conduct of any activity which may result in the discharge of a pollutant," ibid.) may not review it. Thus, nothing in § 511(c)(2) is disturbed by our holding that hydroelectric dams require § 401 state certifications. It is still the case that, when a State has issued a certification covering a discharge that adds no pollutant, no federal agency will be deemed to have authority under NEPA to "review" any limitations or the adequacy of the § 401 certification.