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DEEP Releases Report On Public Health and Air Quality Benefits of Reducing Pollution from Medium and Heavy-Duty Trucks

(HARTFORD)—The Connecticut Department of Energy and Environmental Protection (DEEP) announced today the release of a report issued under Gov. Lamont’s Executive Order 21-3 finding that Connecticut can significantly improve air quality and public health by adopting new emission standards for medium and heavy-duty (MHD) vehicles offered for sale in Connecticut beginning in 2026.


Public Health Impacts of Poor Air Quality:

For almost forty-five years, Connecticut has failed to meet federal health-based air quality standards for ground-level ozone (smog), subjecting generations of Connecticut residents to adverse health and economic impacts.Poor air quality exposure worsens acute and chronic respiratory problems such as asthma, Chronic Obstructive Pulmonary Disease, and other lung diseases.  This past year, Connecticut experienced twenty-one days of unhealthy levels of ozone, and documented some of the highest monitored values on the east coast. A recent national report, Asthma Capitals 2021, ranked New Haven (#5) and Hartford (#17) among the 100 largest U.S. cities where it is most challenging to live with asthma. 

Transportation Sector Contributions to Poor Air Quality:  

The transportation sector is responsible for 67% of the emissions of nitrogen oxides (NOx), a key component of smog. MHD vehicles—which include trucks, buses, and smaller delivery vehicles—account for as much as 53% of NOx emissions, despite being only 6% of the on-road vehicle fleet. The transportation sector is also the largest source of statewide greenhouse gas (GHG) emissions at 37%, and as DEEP’s most recent GHG Emissions Inventory found, emissions from that sector are increasing, when they must decline by roughly one-third in this decade if the State is to meet its GHG emissions reduction target for 2030. MHD vehicles are responsible for 25% of the greenhouse gas emissions from the transportation sector.   

“The choice is clear, adopting the California framework, as most of our neighboring states have already done, will significantly reduce harmful emissions, improve air quality and make significant progress toward achieving our GHG reduction targets,”Gov. Lamont said.  “The gravity of Connecticut’s non-compliance with federal health-based clean air standards requires these reductions now. The protection of residents’ public health and welfare, particularly in our overburdened communities across Connecticut, demands it.” 

“All of us are aware of the current climate crisis we are facing, and without swift and bold action, we will be too late to combat it with real solutions,” said Lt. Governor Susan Bysiewicz. “The protection of public health and welfare, particularly in overburdened communities across Connecticut, is most important. It is imperative that we adopt these standards today to protect our futures.”

About the California Emissions Standards: 

Using a successful model established almost twenty years ago for passenger cars and light trucks, DEEP’s report recommends that Connecticut join several nearby states including New York, New Jersey and Massachusetts in adopting clean truck standards based on those recently adopted by the state of California.  

Adopting the California standards will ensure manufacturers are producing cleaner vehicles and offering them for sale in Connecticut, giving prospective consumers more options. Adoption of these standards would not mandate that Connecticut businesses purchase these vehicles, nor would it place affirmative requirements on those businesses.  The standards apply solely to the Original Equipment Manufacturers (OEMs). The engines produced by OEMs subject to the regulations must be up to 90% cleaner than current standards and they must deliver advanced technology zero emission MHD vehicles to Connecticut.   

Under the federal Clean Air Act, Connecticut cannot independently set its own new vehicle emission standards and has only two options to reduce air pollution from these vehicles: adopt California’s vehicle emission standards, which were formally adopted last year in California, and will go into effect as early as 2025; or wait for the EPA’s recently announced federal standards to take effect, which will likely not occur until 2027 at the earliest. The existing federal standards are over two decades old and do not meet Connecticut’s air quality, climate mitigation, and public health needs.

Benefits to Connecticut Residents:

A review of economic, air quality and public health impacts associated with reducing air pollution from new medium and heavy-duty (MHD) vehicles shows that proactively implementing the suite of California emission standards for new MHD vehicles rather than relying on outdated federal regulations will yield significant benefits in Connecticut, including: 

  • Adopting the California standards will reduce carbon emissions by over 350,000 tons per year in 2050.
  • Adopting the California standards will reduce smog-forming air pollution by over 750 tons per year in 2035 and over 900 tons per year by 2050.
  • NOx and PM emissions reductions associated with MHD EV deployment will save Connecticut $270 million dollars in avoided health care costs over the period of 2020-2040, but could be as much as $500 million to $1.4 billion by 2050.
  • Growing the EV market through complimentary policies designed to support early adoption will lower initial cost of entry to this market and create economic opportunities in MHD EV sales, service and infrastructure support.
  • Increased market penetration of MHD EVs will create greater demand, and consequent investment, in Connecticut’s EV charging network.
  • Adopting the California standards lays the foundation for further regional success, as Connecticut will work with other states who have adopted the standards to identify and implement policies that reduce MHD emissions, aid the adoption of advanced technology vehicles, and improve regional pollution and economic outcomes.
  • Adopting the California standards is a meaningful step toward addressing disproportionate impacts on communities of color and other vulnerable populations located near transportation corridors.

“Cleaner air, better health outcomes, and reductions in our greenhouse gas emissions are all possible if we adopt California’s MHD standards,”DEEP Commissioner Katie Dykes said. “Clean air is a policy choice, and adopting these standards means telling auto manufacturers that Connecticut residents want more options for cleaner operating vehicles that will lead to cleaner air and less money spent on healthcare costs associated with lung diseases aggravated by air pollution from the transportation sector. The consequences of not taking this action are real and immediate- several Connecticut counties face reclassification in the eyes of the EPA, which could meannew and more stringent requirements on stationary sources of air pollution that could affect many large and small businesses in these areas, and continue to take us further away from our GHG emissions reduction goals to mitigate the impacts of the climate crisis. This is an easy choice for Connecticut.”  

Go here to view the report. More information on medium and heavy-duty vehicles available here

Go here to view the fact sheet in support of House Bill 5039, the Governor’s Bill proposing adoption of the California standards.

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DEEP Communications