On Monday, January 4, 2016, the U.S. Department of Justice, acting on behalf of the U.S. Environmental Protection Agency, filed a civil lawsuit in federal district court against Volkswagen, Audi and Porsche (collectively referred to as Volkswagen). The lawsuit alleges that Volkswagen violated the Clean Air Act by installing defeat devices in approximately 580,000 diesel vehicles in the U.S. The defeat devices allegedly detected when vehicles were undergoing EPA emissions tests and turned on emissions controls during the tests so that emissions were reduced to permissible levels, but then turned off emissions controls during normal driving conditions on the road. The lawsuit seeks injunctive relief - including mitigation of excess NOx emissions - and civil penalties up to $60 billion.

The lawsuit contains only civil charges; the Clean Air Act does not provide for criminal penalties. However, as EPA noted in its news release, "A civil complaint does not preclude the government from seeking other legal remedies," and federal prosecutors are continuing their investigation into Volkswagen's actions related to the defeat devices. EPA also stated that it is in discussions with Volkswagen regarding potential remedies and recalls to fix the emissions controls in its diesel vehicles, but those discussions are still ongoing.