California has designated diesel particulate matter (DPM) a carcinogen. To address this issue, the California Air Resources Board developed its Diesel Risk Reduction Plan which is designed to reduce DPM emissions 75% by 2010 and 85% by 2020 versus the year 2000 baseline.
Since 2000, CARB has promulgated in-use diesel rules targeting both on-road and off-road fleets including heavy-duty trucks, buses, public fleets, refuse trucks, cargo handling equipment, marine engines, stationary engines, portable engines and construction/mining equipment. A rule on agricultural equipment is in draft form.
California is the only state regulating in-use engines but other states may opt into the California program. States likely to adopt the California diesel rules include New York, New Jersey, Massachusetts, Connecticut, Vermont, Rhode Island, Maine, Maryland, New Mexico, Pennsylvania, Florida, Arizona, Oregon, Washington, Colorado and Utah.
The number of diesel engines targeted by these rules approaches 1 million in California alone.
Currently, CARB has focused on exhaust treatment systems to reduce DPM. All exhaust treatment systems, especially particulate filters, reduce engine efficiency thereby increasing fuel consumption. A way around this problem is to introduce a pre-combustion product into the engine. Engine dynamometer results at California Environmental Engineering in Santa Ana, California show significant reduction in both exhaust emissions and fuel consumption using combinations of pre-combustion and post-combustion systems on heavy duty diesel engines.
