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Detroit Diesel Corp Clean Air Act

(WASHINGTON, D.C. - October 6, 2016) - The U.S. Environmental Protection Agency (EPA) and the U.S. Department of Justice (DOJ) today announced a settlement with Detroit Diesel Corp. that resolves alleged violations of the Clean Air Act for selling heavy-duty diesel engines that were not certified by EPA and did not meet applicable emission standards. Under the settlement, Detroit Diesel will spend $14.5 million on projects to reduce nitrogen oxide and other pollutants, including replacing high-polluting diesel school buses and locomotive engines with models that meet current emissions standards. Detroit Diesel will also pay a $14 million civil penalty.

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Detroit Diesel Corp. manufactures heavy duty diesel engines, axles, and transmissions for the on-highway and vocational markets. The company is a wholly-owned subsidiary of Daimler Trucks North America and is incorporated in the state of Delaware. 

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The settlement resolves a U.S. EPA enforcement action against Detroit Diesel Corp. for alleged Clean Air Act violations for introducing into commerce 7,786 heavy duty diesel engines in model year 2010 that did not have valid EPA-issued certificates of conformity as required by Section 203(a)(1) of the Clean Air Act, 42 U.S.C. § 7522(a)(1) and that failed to meet 2010 emissions standards.  

The Clean Air Act (CAA) requires manufacturers to obtain a certificate of conformity demonstrating compliance with emission standards before introducing an engine into commerce. Certificates of conformity cover only those engines produced within a single model year. A model year for an engine family of engines ends either when the last such engine is produced, or on December 31 of the calendar year for which the model year is named, whichever date is sooner.

Detroit Diesel commenced construction of the heavy duty diesel engines during model year 2009 but did not complete construction of the engines until calendar year 2010. Because Detroit Diesel completed all manufacturing and assembling processes for the engines in 2010, the engines required a certificate of conformity demonstrating compliance with 2010 emission standards.

From approximately January 5, 2010 through approximately June 1, 2010, Detroit Diesel sold the engines for on-highway use in heavy duty vehicles. Because the engines were not certified to the more stringent 2010 emission standards, Detroit Diesel’s sale of these engines resulted in excess emissions. The engines were manufactured in Detroit, Michigan, but were introduced into commerce across the country. 

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Injunctive Relief

The consent decree requires Detroit Diesel to spend a total of $14.5 million on clean diesel projects. These clean diesel projects include:

  1. Replacing older, high-polluting school buses with new school buses that meet current, more-protective emissions standards. The amount to be spent on this project is $10.875 million.
  2. Replacing or repowering high-polluting switch locomotives, which are locomotives used in ports to move goods short distances. The amount to be spent on this project is $3.625 million.

In addition, Detroit Diesel will be required to post information about these projects on a public website in order to inform the public of actions taken under this settlement. Expanding transparency by making information more accessible to the public is one component of EPA’s Next Generation Compliance

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Pollutant Impacts

The clean diesel school bus and locomotive projects will reduce diesel emissions, which include nitrogen oxide (NOx), particulate matter, hazardous air pollutants and other pollutants. Nitrogen oxide is a precursor to ozone and can lead to acid rain. Diesel exhaust poses a lung cancer hazard for people and can cause respiratory effects such as asthma, and these risks can disproportionately impact sensitive populations such as children.  

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Health and Environmental Benefits

The EPA estimates that each dollar spent to reduce diesel emissions results in $13 of public health benefits. Thus, EPA estimates that $14.5 million spent on clean diesel projects could provide $188.5 million in public health benefits as the result of ambient air pollutant reductions. Also, the indoor air quality improvements (i.e., reduced exposure to diesel exhaust inside of school buses) associated with retiring high-polluting diesel school buses are expected to result in significant additional health benefits.

The projects are expected to be implemented by Detroit Diesel in a manner that seeks projects across many geographic areas, emphasizes project options that reduce cost and maximize environmental benefit and prioritizes areas that are non-attainment for any pollutant or are potential low income areas. 

This enforcement action is part of an ongoing effort by the EPA to protect the public from harmful air pollution by ensuring that all vehicles and engines meet federal emission limits. 

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Environmental Justice Benefits

Vehicles containing the heavy duty diesel engines that failed to meet 2010 emissions standards are mobile sources of emissions, and the emissions produced do not present any unique environmental justice concerns. However, Detroit Diesel’s implementation of the clean diesel projects is expected to reduce NOx and other pollutants in areas disproportionally impacted by mobile source air pollution.

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Civil Penalty

Detroit Diesel Corp. will pay a $14,000,000 civil penalty.

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Comment Period

The proposed settlement, lodged in the U.S. District Court for the District of Columbia, is subject to a 30-day public comment period and final court approval.  During the public comment period, the consent decree may be examined and downloaded at Department of Justice website

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For more information, contact:

Christopher Thompson
Air Enforcement Division
U.S. Environmental Protection Agency
1595 Wynkoop Street (8MSU)
Denver, CO 80202-1129
(303) 312-7156

James Van Orden
U.S. Environmental Protection Agency - Region III
1650 Arch Street (3RC42)
Philadelphia, PA  19103
(215) 814-2693