Multiple coalitions of industry groups have recently filed lawsuits seeking to block California’s new “Omnibus” Low-NOx regulation, which affects businesses across the country that use heavy-duty diesel trucks. The suits, filed in the U.S. Court of Appeals for the Ninth Circuit, challenge the EPA’s decision to rubber stamp the regulation, which sets record-low thresholds for emissions from new heavy-duty vehicles and engines. 

The Clean Air Act generally gives the EPA the power to set vehicle emissions standards for the country, while forbidding states from creating their own alternative standards. But the Act exempts California (and only California) from that prohibition, allowing it to craft its own vehicle emission standards. Once the EPA approves California’s standards, every state must choose either the EPA’s standards or California’s standards. To date, 17 states (including Pennsylvania) and D.C. have implemented standards created by California under this federal regime. 

Many of PMTA’s members are all too familiar with California’s burdensome emissions regulations, since Pennsylvania adopts California’s standards for emissions for heavy diesel engines on a rolling basis. PMTA is a named plaintiff in a separate lawsuit, filed in the Commonwealth Court of Pennsylvania, challenging the state regulations that purportedly permit this rolling incorporation of California law in the Commonwealth of Pennsylvania.  

The petitions for review filed in the U.S. Court of Appeals for the Ninth Circuit are available here and here.