26 June 2003
The San Francisco Bay Area’s Metropolitan Transportation Commission (MTC) has allocated funding to help finance the purchase of nearly 1,700 retrofit emission control systems that will be installed on diesel buses operated by 12 Bay Area transit agencies. The funding, which will be spread over the 2003-04 and 2004-05 fiscal years, comes from the federal Congestion Mitigation and Air Quality (CMAQ) program ($13.8 million) and from local matching funds allocated by MTC ($1.8 million).
The buses will be retrofitted with the Longview emission control system supplied by Cleaire Advanced Emission Controls of San Leandro. The Longview device is a combination of an active lean NOx catalyst—using diesel fuel, injected upstream of the system, as a NOx reductant—with a catalyzed, silicon carbide diesel particulate filter. Fuel injection and other functions of the system are controlled by an electronic control unit called the "monitor-logger-controller" (MLC), based on the measured exhaust gas temperature, system pressure drop, and signals from engine sensors.
The Cleaire Longview system was recently verified by the California Air Resources Board to provide 85% reduction of PM emission and a 25% reduction of NOx.