Editor’s note: The authors served as counsel for East Buffalo Township in Gallagher v. East Buffalo Township.

Stormwater is a significant contributor to water pollution across the United States. This is because stormwater is an inherently polluted substance, which invariably collects debris, pesticides and other contaminants from the ground before flowing into streams, rivers and lakes. Given its unique nature, stormwater runoff has presented a series of problems since the adoption of the federal Clean Water Act (CWA), 33 U.S.C. §1251-1387, in 1972.

The CWA was passed to restore and maintain the integrity of the nation’s waters and typically prohibits the discharge of any “pollutant” from a “point source” into the waters of the United States without a National Pollutant Discharge Elimination System (NPDES) permit. Recently, however, the U.S. District Court for the Middle District of Pennsylvania ruled in Gallagher v. East Buffalo Township, No. 4:12-cv-00777 (M.D. Pa. Aug. 29, 2013), that the operator of a small municipal separate storm sewer system (or small MS4) is not required to obtain an NPDES permit for “discharges composed entirely of stormwater,” where the operator is not actively adding pollutants to the stormwater handled by its MS4.

Gallagher is the first decision to address the issue in the Third Circuit, and only the fourth court nationally to tackle the meaning of the statutorily-undefined term. Because of its exhaustive reasoning, however, Gallagher will likely become the authoritative opinion on the matter, and in the process, impact many municipalities in the state and across the country.

By way of background, the CWA generally prohibits the discharge of any “pollutant” from a “point source” into the waters of the United States without an NPDES permit. For purposes of the CWA, “point source” means “any discernible, confined and discrete conveyance … from which pollutants are or may be discharged,” while a “pollutant” broadly includes “dredged spoil, solid waste … sewage, garbage, rock [and] sand.” Thus, on its face, the CWA seemingly prohibits the unpermitted discharge of stormwater from a point source into the nation’s waters.

Under the CWA and its implementing regulations, however, an operator of a small MS4 is exempt from the NPDES permitting scheme for “discharges composed entirely of stormwater,” subject to certain limited exceptions. Neither authority, though, defines the phrase.

Prior to Gallagher, three federal district courts in the Ninth Circuit had addressed the term’s meaning, with two holding that “discharges composed entirely of stormwater” means what it says — i.e., discharges composed completely of stormwater — and the other concluding that the phrase denotes stormwater runoff plus those pollutants that are introduced to runoff by incidental means. (Compare Environmental Protection Information Center v. Pacific Lumber, 301 F. Supp. 2d 1102 (N.D. Cal. 2004), and Humboldt Baykeeper v. Union Pacific Railroad, No. 06-02560 JSW WDB (N.D. Cal. Oct. 16, 2008), with Rosemere Neighborhood Association v. City of Vancouver, (W.D. Wash. Oct. 18, 2005).)

Amid this backdrop, the plaintiff in Gallagher instituted a citizen suit against the township, alleging, inter alia, that it violated the CWA by discharging stormwater from a drainage pipe onto her property and into an unnamed tributary of the Susquehanna River without an NPDES permit. Following the close of discovery, the parties filed cross-motions for summary judgment. The district court granted the township’s motion, entered judgment in its favor on the CWA claim, and relinquished jurisdiction over the remaining state-law claims.

Initially, the district court observed that the parties’ motions turned on whether the discharges from the township’s MS4 are “composed entirely of stormwater.” The court noted, however, that the term is not defined by law or regulation, and that the parties disagreed as to its meaning. According to the court, the plaintiff, Violet Gallagher, had argued that the relevant language means stormwater, not pollutants, while the township had contended that a discharge meets the definition even if it includes pollutants that are incidental to stormwater runoff.

The district court acknowledged that Gallagher’s interpretation is “appealing in its simplicity,” but concluded that such an interpretation “makes little sense when viewed in the context of the statutory scheme.” The court also determined that Gallagher’s position is “at odds with the limited legislative history behind the Water Quality Act of 1987,” which amended the CWA.

On this point, the court reasoned:

“A major goal of the legislation was to substantially reduce stormwater-related permit applications by limiting the description of point sources required to obtain permits. But if every discharge of stormwater containing pollutants was ineligible for the permit exemption because … the discharge was not ‘composed entirely of stormwater,’ the legislation would do no such thing. … It is hard to imagine legislators defining ‘discharges composed entirely of stormwater’ as ‘stormwater, not pollutants,’ when doing so would have undermined a major purpose of the relevant provision.”

The district court thus held that an otherwise exempt operator of a small MS4 is not required to obtain a permit, where its MS4 “discharges pollutants collected and conveyed solely as an incident to the collection and conveyance of stormwater.”

While still in its infancy, it stands to reason that Gallagher will have far-reaching consequences in the Third Circuit and beyond. This is because the universe of small MS4s includes every MS4 in the United States except the approximately 900 medium and large MS4s. Thus, assuming that future courts adopt Gallagher‘s holding, the decision will insulate the vast majority of municipalities from liability under the CWA, where, as in Gallagher, a plaintiff institutes a citizen suit against the municipality for damages resulting from stormwater runoff. Gallagher therefore could represent a majority victory for municipalities nationwide.

Paul J. Bruder Jr. is a partner at Rhoads & Sinon and serves as the chair of the firm’s environmental law and natural resources practice group.

Casey A. Coyle is an associate at the firm, a member of its appellate, business litigation, environmental law and natural resources practice groups, and former law clerk to Pennsylvania Supreme Court Justice Thomas G. Saylor.