Under the direction of Fleet Manager Allen Mitchell, the Snohomish County Public Works Department has implemented a number of strategies outlined in an initiative designed to create a voluntary certification program. Mitchell serves on the Puget Sound Green Fleets Standard Advisory Committee; his operation was recently honored as the third-best government green fleet in North America by100 Best Fleetsmagazine.
Developed in the 1970s, “canola” stands for “CANadian Oil, Low Acid.” So far, a 15-ton/hour Mathews Co. Model 675 continuous flow dryer (center, red) has processed 350 tons of the seed, 40% of which is oil, using 25% of the available BTUs from the gas stream. Snohomish County is awaiting the arrival of a 24-ton crusher to extract oil from the dried seed for biodiesel. The white propane tank stores gas for the ignition sequence. Photos: Snohomish County Public Works Department

In Snohomish County, Wash., just north of Seattle, efforts to reduce pollution have gone beyond forging and strengthening connections among local agencies and businesses. The county's goal to convert its diesel vehicles to B20 biodiesel by 2010 and B40 by 2014 is pulling local farmers into the action as well.

While the transition has gone smoothly, several factors were threatening the timetable.

About two-thirds of the county's fleet — mostly larger pickup trucks, dump trucks, and off-road equipment — already is running on B20, using 25,000 to 30,000 gallons/month and cutting the county's carbon emissions by 925,000 pounds.

“We did some research before making the change, and found no records of damage claims resulting from the use of biodiesel or any cases where warranty coverage was denied on account of its use,” says Department of Public Works Fleet Manager Allen Mitchell. “Changing to B20 hasn't required any real modification of the equipment, but we've had to adjust maintenance procedures. Bio-diesel fuel has a solvent effect that loosens deposits in the engine that then get trapped in filters, so we have to check and change filters more often.”

But while ASTM standards have been established for B20 and B100 (100%) biodiesel, there aren't any for intermediate grades like B40. Another stumbling block was the available supply of biofuels. To address the latter, the county has embarked on an ambitious program to encourage local production of viable feedstock crops.


In 2005, local farmers approached County Executive Aaron Reardon in hopes of developing markets for locally grown products. As luck would have it, these discussions coincided with the county's search for ways to reduce its use of foreign oil and cut down its petroleum-based diesel emissions.

The county provided initial funding worth about $80,000 to develop trial runs for canola during a two-year period. Within months, local farmers were growing biodiesel seed crops to test their viability. Canola seed produces oil that can be used for a bio-fuel, but canola seed grown in western Washington must be dried to reduce its moisture content before storage or processing. With help from local, state, and federal funding sources, the county also began building infrastructure to process canola and other crops locally.

After the trials proved successful, another $410,000 of county money plus federal appropriations worth $344,400 were made available last year to buy a seed dryer. The dryer was installed at the county's Cathcart Operations Center, adjacent to a closed landfill, so that landfill gas that had been previously just flared off can fuel the dryer. Using landfill gas rather than traditional fuels such as natural gas or propane significantly reduces the cost to dry the seed. It also provides obvious environmental and social benefits.

A seed crusher purchased with $500,000 in state Energy Freedom funds was also installed at the Cathcart site. Crushing extracts the canola oil so it can be processed as biofuel. The resultant seed hulls are being used by Wolfkill Feed and Fertilizer Inc. of Monroe, Wash. — another project stakeholder — to produce cattle feed.

Whole Energy Fuels of Bellingham, Wash., converts the extracted oil to biodiesel before transporting it to a refinery in nearby Anacortes, where it's blended with petrodiesel to B20 specifications. The fuel is then supplied to Pacific Pride “Petrocard” stations where drivers and operators refill their vehicles. The electronic card system allows the county to manage and monitor fuel use.