Steven G. Bradbury is a Distinguished Fellow at The Heritage Foundation. Mr. Bradbury previously served as general counsel of the U.S. Department of Transportation (DOT) from November 2017 until January 2021 and in the Justice Department’s Office of Legal Counsel from 2005 to 2009 as Principal Deputy and Acting Assistant Attorney General.

Following up on my September 7th WLF Legal Backgrounder, California’s Attempt to Dictate Locomotive Technology for our National Rail System Unlawfully Conflicts with Federal Law, there’s been an important (though perhaps not surprising) development: The Environmental Protection Agency has decided to sacrifice the consistency of federal environmental rules in favor of accommodating California’s aggressive plan to transform the rail industry.

In a final rule entitled “Locomotives and Locomotive Engines; Preemption of State and Local Regulations,” the EPA has amended its Clean Air Act regulations to narrow dramatically the effective scope of federal preemption of state efforts to control locomotive emissions.

The Clean Air Act preempts states from regulating the emissions of “new” locomotives or locomotive engines and allows EPA to authorize California (and only California) to set its own emissions limits for non-new locomotives and engines (which other states may then follow). See 42 U.S.C. § 7543(e)(1) & (2).

For many years, EPA’s rules have defined a locomotive or locomotive engine to be “new” for preemption purposes (thus free from potential state regulation) until it reaches 133 percent of its useful life following original manufacture or remanufacture. See 40 CFR § 1074.12(b) (former rule still in effect as of November 6, 2023). This extended period of preemption has ensured consistency, predictability, and certainty in environmental regulation of locomotives, as Congress intended.

Now EPA is doing away with this preemption period entirely and thus purports to allow California potentially to impose environmental emissions requirements on locomotives and locomotive engines immediately upon their transfer to an operator after original manufacture or remanufacture.

The rule change does not by itself authorize the In-Use Locomotive Regulation issued by the California Air Resources Board (CARB), but it represents an obvious and intentional step in that direction by the Biden administration. The Biden EPA has shown no reluctance in authorizing California to impose ultra-aggressive climate change regulations on new cars and trucks, including zero-emission vehicle mandates, under a parallel preemption-waiver provision of the Clean Air Act—which EPA has interpreted to render such authorizations virtually automatic.

There are still substantial legal impediments, however, to the EPA’s greenlighting of CARB’s locomotive regulation and to California’s ability to enforce it.

Even if the Clean Air Act allowed CARB to impose emissions limits on all in-use locomotives, as EPA’s new rule change seems to contemplate, the Spending Account obligation in CARB’s regulation and the provisions requiring locomotive operators to purchase or lease only zero-emission locomotives going forward would still fall within the plain terms of Clean Air Act preemption. These requirements are designed to ensure that all new locomotives purchased or leased for use in California will satisfy CARB’s preferred emissions standard (zero emissions), and thus they clearly relate to the control of emissions from new locomotives. Congress has given EPA no authority to waive Clean Air Act preemption as applied to these requirements, no matter how narrowly EPA defines “new.”

Moreover, of course, EPA does not administer and cannot alter the scope of preemption under the Interstate Commerce Commission Termination Act, which covers the economics and business practices of railroads, and the Locomotive Inspection Act, which governs the safety of all rail equipment and operations. As I explained in the WLF Legal Backgrounder, the preemptive sweep of these other federal statutes is quite broad: The former would invalidate the entirety of CARB’s locomotive regulation as applied to railroads, regardless of what EPA does, and the latter would certainly bar the idling restrictions CARB hopes to impose on locomotive operators.

Perhaps the most significant thing about EPA’s decision to surrender so much of its regulatory mandate to California is what it says about the Biden administration’s willingness to overthrow Congress’s carefully crafted system of uniform federal rail regulation in common pursuit with CARB of unrestrained climate activism.