A Windham resident has been sentenced in Portland, Maine, for conspiring to tamper with environmental monitoring devices on diesel vehicles and obstructing an Environmental Protection Agency (EPA) investigation. Isaac Allen, 35, received a three-year probation sentence and a $40,000 fine from U.S. District Judge Nancy Torresen. This penalty aligns with the maximum amount recommended by the United States Sentencing Guidelines for his offense level.
As part of his probation terms, Allen must ensure compliance with the Clean Air Act for all vehicles he owns or operates through any associated company. These vehicles must have all required emissions controls and an operational on-board diagnostic system (OBD). Allen pleaded guilty to these charges on November 20, 2024.
The Clean Air Act aims "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." It mandates that diesel trucks maintain systems limiting harmful emissions. Additionally, these systems should be monitored by an OBD capable of detecting non-functional or removed emissions control components. Tampering with the OBD is considered a felony.
Between January 2017 and September 2020, Company A—a co-conspirator—referred customers to Allen for downloading illegal software known as "tunes" onto their vehicles' OBDs. This software prevented detection of disabled emissions controls. In response to an EPA information request under the Clean Air Act, Allen submitted false documentation understating the number of illegal tunes installed.
The EPA estimates that using emissions control defeat devices can increase pollution emissions from a single diesel pickup truck by up to 100 times. Diesel exhaust contains harmful acidic and hydrocarbon gases linked to various adverse health effects such as respiratory irritation and aggravated asthma.
This case was referred by Maine State Police and investigated by EPA's Criminal Investigation Division.
