Montana District Court Vacates EPA's 'Secret Science' Rule

The Environmental Protection Agency’s (EPA’s) “Secret Science” rule establishing new standards for consideration of certain “pivotal” scientific studies, which was slated to go into effect on Jan. 6 of this year, has been vacated and remanded by the U.S. District Court for the District of Montana.

The decision reached Feb. 1 impacts the power generation industry, particularly as it concerns the use of scientific data to help with regulatory issues about pollutants and air quality.


The decision follows one from a few days prior in which the court rejected EPA’s attempt to make the rule immediately effective. Notably, both decisions rely on the same basic principle—that the rule is not merely procedural, as EPA claimed, but substantive. That determination could be important for other rules the Trump administration’s EPA characterized as procedural in nature, but that have been challenged as having substantive effect.

Mack McGuffey

Originally, the so-called “Secret Science” rule was slated to go into effect immediately upon publication in the Federal Register, based on EPA’s claim that it was only an administrative rule that should be exempt from notice-and-comment procedures under the Administrative Procedure Act (APA). The court rejected this argument in an initial decision issued Jan. 27 that delayed the rule’s implementation, granting a motion for summary judgment by environmental groups challenging the rule. In that decision, the court held that the rule is no mere housekeeping measure because it directed EPA on how to weigh evidence, and thus had important substantive implications for future rule-making actions.

The court’s ruling Monday applies that same thinking—that the rule is not merely administrative in nature, but substantive—to vacate it entirely. Since the court had already held in its Jan. 27 opinion that the rule was too substantive to fall within the exception to the APA, the court likely concluded that it also exceeded EPA’s “housekeeping” authority under 5 U.S.C. 301, which EPA had originally identified as the legal foundation for the rule.

Louise Dyble

Notably, it wasn’t the challengers to the rule that asked for vacatur, but EPA itself. While the first decision in late January, which held that the rule did not qualify to go into effect immediately, granted a motion filed by challengers, the second motion to vacate the rule granted EPA’s own motion for vacatur and remand. The fact that EPA filed a motion to seek vacatur of its own rule just days after inauguration shows the Biden administration EPA has hit the ground running in trying to reverse highly controversial policies from the Trump administration.

The district court’s decision could have implications for several EPA measures adopted to improve transparency during the Trump administration that were based on the agency’s housekeeping authority, including a rule governing the adoption and rescission of significant guidance issued in September 2020.

These two decisions could impact the power industry in few ways.  First, and most directly, the loss of the “Secret Science” rule means that EPA may consider a broader range of scientific studies, even if the underlying data is not readily available for analysis by all stakeholders and the public. That result is relevant for the power industry because many of the air rules affecting the power sector are highly technical and lean on reams of scientific studies about the effect of air pollutants on human health and the environment. 

Second, the air rules affecting the power industry are also often the subject of hundreds or even thousands of guidance documents, which can affect how the rules are applied in individual cases.  If the downfall of the “Secret Science” rule foreshadows a similar fate for EPA’s attempt to simplify  the process for developing and issuing agency guidance as well as to reduce contradictory or outdated analysis, it could lead to less regulatory certainty.

Mack McGuffey is a partner with Troutman Pepper, specializing in the Clean Air Act. Louise Dyble is an associate with Troutman Pepper, focused on the environment. For more details on the substance of the “Secret Science” rule, see Troutman’s previous blog post on the rule. For more information on the rule, or for updates on pending legal challenges, please contact Mack McGuffey at [email protected], or Louise Dyble at [email protected].

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