Tenth Circuit Grants Standing to NonProfit Seeking to Enforce Clean Air Act Tampering Provisions

January 26, 2022

A unanimous three-judge panel in the US Court of Appeals for the Tenth Circuit affirmed on December 28, 2021 that private citizens and environmental groups have the right to seek enforcement of the Clean Air Act’s anti-tampering provisions under its citizen-suit provision, 42 USC § 7604.

The ruling involves an action brought by an environmental nonprofit group, the Utah Physicians for a Healthy Environment (UPHE), against the celebrity mechanics known as the Diesel Brothers, alleging that the Diesel Brother’s removal and modification of emission-regulating products in vehicles led to harmful emissions and adverse health effects for residents of northern Utah. This decision addresses both Article III standing and statutory standing requirements for citizen suits brought under the Clean Air Act (CAA).

The Tenth Circuit Rejects the “Meaningful Contribution” Standard in Favor of a More Relaxed Article III Causation Standard

The Diesel Brothers attempted to argue that UPHE did not satisfy Article III standing on two grounds, which the court referred to as a factual and legal ground. The factual ground was based on the Diesel Brothers’ assertion that UPHE had not shown that the Diesel Brothers’ actions had caused UPHE’s injury in fact. The Diesel Brothers argued that the diesel truck modifications at issue did not cause UPHE’s alleged injuries as they contributed “a negligible fraction of the total pollution that comes from a myriad of sources.” Rejecting this reasoning, the court noted that adopting the proposed causation requirement would limit the availability of citizens suits to cases involving only the largest polluters, cutting against what Congress likely intended when implementing the CAA.

The court also rejected the Diesel Brother’s legal argument asserting that UPHE did not have standing under the US Supreme Court’s “meaningful contribution” standard as articulated in Massachusetts v. EPA, 549 US 497 (2007). Under this standard, Article III standing does not arise unless the regulation sought to be enforced is shown to have a substantial causal connection with the harm sought to be avoided. This argument was also rejected given the court’s doubts that the Supreme Court “was instituting a general meaningful-contribution requirement that would apply even when the causal link is merely between the emission of noxious gases and harm to those who breathe the air into which the gases are emitted.” The court therefore held that UPHE had Article III standing to challenge the Diesel Brothers’ violations “that contributed to unhealthy air in the Wasatch Front.”

The Tenth Circuit Adopts a Broad Reading of “Emission Standard or Limitation” for the Purpose of Statutory Standing Under the CAA

The Diesel Brothers also argued that UPHE did not have statutory standing under CAA’s citizen suit provision. They noted that the CAA and Utah’s Clean Air Act state implementation plan provide that citizens suits may only be brought as enforcement actions against violations of “an emission standard or limitation” under the CAA or an order “with respect to such a standard or limitation.” Defendants therefore argued that suits brought because of the distribution or manufacture of emission-control and defeat devices are unrelated to violations of emission standards as defined under the CAA or state implementation plan, and therefore create an improper basis for citizens suits. The court instead read the definition of “emission standard or limitation” more broadly, as encompassing “any requirement relating to the operation or maintenance of a source to assure continuous emission reduction,” to be more in line with what the CAA citizen suit’s provision seeks to authorize.[1] By adopting this broader reading, citizens in the Tenth Circuit now have standing to bring suits under the CAA against defendants allegedly involved in the in-state sale and production of emission-control or defeat devices.

The Tenth Circuit Limits the Scope of Civil Penalties

While this decision may embolden private citizens and groups to bring enforcement actions under the CAA’s citizen suit provision in the Tenth Circuit, the court provided a limiting principle based on Fifth, Seventh, and DC Circuit precedents. The court noted that future plaintiffs may lack standing if their claims are related to the actions of a “too-distant polluter.” More specifically, where a defendant does not violate the CAA within the community where a harm is alleged to have occurred, standing requirements will not be met. Therefore, the Tenth Circuit concluded that the Diesel Brother’s conduct resulting in out-of-state emissions or the marketing of defeat devices that were never sold, was not enough to satisfy standing requirements under the CAA citizen suit provision. As such, the issue of civil penalties levied against the Diesel Brothers for CAA violations occurring out of state was remanded to recalculate what is owed, based solely on violations whose negative impact occurred within the community identified in the complaint.


If you have any questions or would like more information on the issues discussed in this LawFlash, please contact any of the following Morgan Lewis lawyers:

Los Angeles
James J. Dragna
Rick R. Rothman
David K. Brown
David S. Yates 

John McGahren
Christopher J. McAuliffe

San Francisco
Ella Foley Gannon

Washington, DC
Duke K. McCall, III
Bryan M. Killian

[1] The court noted and rejected the Ninth Circuit’s narrow interpretation of the term “emission standard or limitation” in the context of the CAA’s citizen-suit provision.