Windham Man Sentenced for Clean Air Act Conspiracy and Obstructing EPA’s Investigation

PORTLAND, Maine: A Windham man was sentenced on Wednesday in U.S. District Court in Portland for conspiring to tamper with environmental monitoring devices on diesel vehicles, in violation of the Clean Air Act, and for obstructing the investigation of the Environmental Protection Agency (EPA) into those violations.

U.S. District Judge Nancy Torresen sentenced Isaac Allen, 35, to a three-year term of probation and a $40,000 criminal fine, the maximum amount recommended by the advisory United States Sentencing Guidelines for Allen’s offense level. As a term of his probation, Allen must ensure that all vehicles he owns directly or through any associated company are in compliance with the Clean Air Act by having all required emissions controls and an on-board diagnostic system (OBD) functioning within its original parameters. Allen pleaded guilty on November 20, 2024.

The purpose of the Clean Air Act, among other things, is “to protect and enhance the quality of the Nation’s air resources so as to promote the public health and welfare and the productive capacity of its population.” Under the Clean Air Act, diesel trucks are required to have working systems and components that limit harmful emissions of pollutants which may endanger public health. The Clean Air Act also requires that those systems be monitored by an OBD that will detect if an emissions control component is not working or has been removed. It is a felony to tamper with the OBD.

On multiple occasions between January 2017 and September 2020, a co-conspirator, Company A, which disabled emissions controls systems on diesel engine vehicles, referred its customers to Allen to download and install illegal software. The illegal software, known as “tunes,” was designed to prevent the vehicles’ OBDs from recognizing the disabling of the emissions controls. Allen would plug into vehicles’ OBD ports and download illegal software tunes through the internet onto the OBD. In response to a Clean Air Act Request for Information by EPA, Allen submitted a false document that materially underrepresented the number of illegal tunes he had installed.

EPA estimates that the installation of emissions control defeat devices can result in an increase of 10-100 times more air pollution emissions from a single diesel pickup truck. Diesel exhaust contains a mix of acidic and hydrocarbon gases that are harmful to human health. Those emissions cause a variety of adverse health effects, including eye, nose, and throat irritation; inflammation and irritation of the respiratory system; difficulty breathing; reduction in lung function; susceptibility to respiratory infection; and aggravation of asthma.

This case was referred to EPA by the Maine State Police and investigated by EPA’s Criminal Investigation Division.   

###