Colorado is the latest state to adopt California’s Advanced Clean Trucks rule, as well as its low-NOx regulations. On April 21, Colorado’s Air Quality Control Commission adopted new rules to promote access to zero-emissions trucks.

It says these new measures will:

• Give Colorado businesses and consumers more options when buying zero-emission trucks.

• Reduce maintenance, operating, and fuel costs for zero-emission-truck owners.

• Dramatically reduce greenhouse gas emissions

• Reduce air pollution emissions, such as nitrogen oxides and particulate matter, that lead to the formation of harmful ground-level ozone pollution. 

The state health department’s Air Pollution Control Division developed the rules and proposed them to the commission. After a multi-day hearing with public comment, the commission voted to adopt two of the rules as the division proposed them, the Advanced Clean Trucks rule and the Low NOx Truck rule.

The Advanced Clean Trucks rule sets a sales standard for manufacturers to make more zero-emission trucks available in Colorado. It takes effect for trucks starting with model year 2027, and the sales standard percentage grows incrementally through model year 2035. This rule will only apply to manufacturers of medium- and heavy-duty trucks. It does not require Colorado businesses or consumers to purchase a zero-emission truck.

Colorado is the eighth state to adopt the ACT rule and the first interior state to adopt it, according to Ceres. Other states that have finalized the rule are all on the coast, include California, Massachusetts, New Jersey, New York, Oregon, Vermont, and Washington. North Carolina and Maryland are also in the process of adopting the policy.

The Low-NOx Truck rule sets more stringent air pollution emissions standards for heavy-duty vehicles, improves testing requirements for engines, and extends warranties. It takes effect for trucks starting with model year 2027. NOx refers to nitrogen oxides, which form ground-level ozone pollution when they react with other pollutants in heat and sunlight. The rule will lower the nitrogen oxide emissions standard for new vehicles by 90% compared to the current standard.

The commission made some changes to the division’s proposal for a third rule, the Large Entity Reporting rule. It will still only apply to operators with a fleet of 20 or more trucks. However, as the Public Service Company of Colorado suggested, the division will collect this information twice, instead of once. The first reporting deadline is Nov. 30, 2024. The second reporting deadline is Dec. 31, 2027. As the Environmental Justice Coalition suggested, the division will also make all of this data publicly available. 

The division proposed the clean trucking rules to help meet goals in the Colorado Greenhouse Gas Pollution Reduction Roadmap. The roadmap directed the division to develop a holistic Clean Truck Strategy and to consider proposing these rules as part of that effort. 

To help cover up-front costs, the division recently opened two grant programs for applications to fund clean vehicles. The federal Inflation Reduction Act created significant incentives for zero-emission trucks. These include up to $40,000 off the purchase price of clean trucks through a new federal tax credit. Colorado is also positioned to access significant federal funding to assist in deployment and reduce up-front costs for zero-emission trucks.

Ceres issued a statement praising the action, saying, “The ACT rule has garnered widespread support from major business interests, including more than 85 companies that signed a letter urging governors across the country to adopt the policy. Companies are eager to electrify their fleets to save on fuel and maintenance costs and meet their own climate goals. The ACT rule will help ensure sufficient supply for zero-emission trucks and vans to meet this growing demand from businesses in Colorado.”

“The ACT rule is a critical precondition for a smooth transition to a zero-emission medium- and heavy-duty market. It will also go a long way toward advancing Colorado’s climate objectives for net-zero greenhouse gas emission reductions, improving air quality, and providing high-quality jobs for Coloradans,” said Alissa Burger, regional policy director for Calstart.