EPA's Letter to Transport Topics
This letter is in response to Transport Topics’ front-page articles ("EPA Knew Its Engine Tests Were Flawed, Volvo Says," Nov. 23, and "Evidence Grows That EPA Knew About Diesel Engine Test Flaws," Dec. 21) and accompanying editorials ("Clearing the Air?" Nov. 23, and "The EPA and Accountability," Dec. 21) on the recent settlements between the United States and several diesel engine manufacturers.
In both editorials, Transport Topics asked EPA to respond to claims made by representatives from Volvo Truck Corp. that the agency had known for years, without taking any action, that its emissions tests did not properly measure emissions of oxides of nitrogen (NOx) under highway operating conditions. The articles and editorials, suggested, therefore, that the environmental problem caused by the engines in question was the result of EPA’s flawed emission test procedures and not the actions of the engine manufacturers.
Volvo’s assertion that EPA has known for years that its emissions tests did not properly measure NOx emissions when a truck is driven on the highway is simply not true. Volvo apparently bases its claim on the fact that, several years ago, EPA received information indicating that individual engines might have contained emission control strategies that increased NOx emissions during steady state operation, such as highway driving, but not during EPA’s official emission test. This information was not provided to EPA by the engine manufacturers involved in the recent settlement, but instead was submitted as comments by interested parties during various rulemaking proceedings, and in contacts with the agency from individual parties. EPA investigated these claims, but did not find indications of the widespread use of these strategies until 1997.
EPA’s inability to substantiate the use of these illegal emission control strategies until 1997 is not surprising given the facts of the situation. First, at no time before EPA’s discovery of their use in 1997, did any of the engine manufacturers involved in the recent settlements notify EPA of the existence or true nature of the illegal emission control strategies in question. Second, the illegal strategies are specifically designed not to operate during EPA’s official emission tests, making detection of the strategies very difficult. Third and finally, the illegal strategies are complicated software programs, requiring lengthy and burdensome review of computer codes and unconventional test methods to determine how they work.
The suggestion that the environmental problem caused by the engines in question was the result of EPA’s flawed emission test procedures and not the actions of the engine manufacturers misses the point that the engine manufacturers com-mitted serious violations of the Clean Air Act’s prohibition against defeat devices. Simply stated, a defeat device is a part (including software) installed on an engine by a manufacturer that renders the emission control system inoperative under driving conditions that are not substantially included in EPA’s official emission test. The emission control strategies in question were specifically designed not to operate during EPA’s emission tests, but to turn off a truck engine’s NOx control system during extended highway driving. These strategies clearly fall within the Clean Air Act’s prohibition against such devices. These are the same types of violations for which General Motors paid an $11 million penalty and recalled more than 500,000 Cadillacs in 1995 and Ford Motor Company paid a $2.5 million penalty and recalled 60,000 Econoline vans in June of this year.
iven the nature of the violations and the magnitude of the excess emissions involved, we believe the recent settlements with several truck engine manufacturers are appropriate, fair and in the public interest.
