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Press Release

Diesel Trucking Companies Conspire to Violate Clean Air Act

For Immediate Release
U.S. Attorney's Office, District of Colorado

Denver – The United States Attorney’s Office for the District of Colorado announces that Pro Diesel Inc. and Endrizzi Diesel, LLC were sentenced this month for conspiring with a Colorado-based diesel shop to tamper with the computers that monitor emissions control systems on Class 8, commercial heavy-duty diesel trucks.

Both diesel shops previously pled guilty to conspiring with a Colorado diesel shop identified as “E.D.” to disable the vehicles’ on-board diagnostic systems (“OBDs”) software programming, in violation of Title 18, United States Code, Section 371. The diesel shops deleted emission controls on the vehicles and hired E.D. to disable the OBDs so they would no longer detect the malfunctions in the emissions control systems, allowing the vehicles to run seemingly normally. This tampering enabled the vehicle owners to avoid maintenance costs. However, as a result of removing the emission controls, the vehicles release tons of excess nitrogen oxides, carbon monoxide, non-methane hydrocarbons, and particulate matter. The excess pollutant load is particularly substantial because Class 8 vehicles are the heaviest class of vehicle and include the semi-tractor trailers that were tampered with in this case. These toxic pollutants contribute to high levels of ozone and smog and present a danger to public health.

Missouri-based Endrizzi Diesel, LLC admitted to paying E.D. more than $149,000 to disable the OBDs on approximately 60 Class 8 heavy-duty trucks, and Iowa-based Pro Diesel Inc. admitted to paying E.D. more than $76,000 to disable the OBDs on 34 Class 8 heavy-duty trucks. A third diesel shop, Wisconsin-based McDermid Sales & Service, Inc., pled guilty on May 26, 2022 to conspiring with E.D. to violate the Clean Air Act. McDermid admitted to paying E.D. more than $71,000 to disable the OBDs on approximately 32 Class 8 heavy-duty trucks. 

Both Endrizzi Diesel and Pro Diesel were sentenced to three-year terms of probation that include stringent monitoring, compliance, and reporting requirements to ensure that neither shop engages in further emissions tampering. Both shops also agreed to pay fines, with a portion of the penalty directed towards community service projects designed to address the environmental harms that resulted from each defendant’s conduct. Endrizzi Diesel was ordered to pay $110,000 to the Walnut Grove, Missouri school district to help purchase cleaner school buses, as well as a fine of $55,000 to the general court fund. Pro Diesel was ordered to pay $77,500 to the Des Moines Area Community College to develop a curriculum to teach diesel mechanic students about emission controls on diesel engines, how to detect tampering, how to restore tampered vehicles, and the legal ramifications of tampering violations. Pro Diesel was also ordered to pay a fine of $38,750 to the general court fund. 

“The primary purpose of the Clean Air Act is to protect the quality of the nation’s air resources. When companies or individuals conspire to violate this federal law, they must be held accountable,” said U.S. Attorney Cole Finegan.

“By deleting the emission controls from heavy duty Class 8 vehicles and overriding the on-board diagnostics system that monitors these controls, the defendants are responsible for the release of tons of excess pollutants,” said Lance Ehrig, Special Agent in Charge of the Environmental Protection Agency’s Criminal Enforcement Program, West-Central Region. “This illegal practice and the excess pollutants emitted have serious consequences for air quality and public health. These sentencings clearly demonstrate the EPA’s commitment to vigorously enforce laws designed to protect public health and the environment.”  

Pro Diesel, Inc. was sentenced by Judge Daniel Domenico on June 14, 2022. Endrizzi Diesel was sentenced by Judge Regina Rodriguez on June 29, 2022. McDermid Sales & Service, Inc. will be sentenced by Judge Philip A. Brimmer on August 5, 2022.

These cases are being prosecuted by Assistant United States Attorney Rebecca Weber and Special Assistant United States Attorney Linda Kato.

Case numbers: 22-cr-00064-RMR, 22-cr-00062-DDD, 22-cr-00065-PAB.

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Deborah Takahara
Public Affairs Specialist

Updated June 30, 2022