Western States Trucking Association, Inc. v. EPA

The trade association petitioners submitted a statement of issues listing four issues they plan to raise: (1) whether carbon dioxide is an “air pollutant” under the Clean Air Act; (2) whether the final rule violates the nondelegation doctrine; (3) whether the rule violates the major questions doctrine: and (4) whether the rule is arbitrary, capricious, or otherwise contrary to law or fact.

Two trade associations—Western States Trucking Association, Inc. and Construction Industry Air Quality Coalition, Inc.—filed a challenge to EPA's Phase 3 greenhouse gas emissions standards for heavy-duty vehicles.