Metro celebrates Earth Day by 'closing the loop'

By the end of the month, King County Metro Transit will receive its first shipment of fuel made from crops grown by Eastern Washington farmers. The biodiesel is made from canola seed grown on Yakima County farms and fertilized with biosolids from King County's two wastewater treatment plants.

King County Executive Ron Sims speaks at the Earth Day event.

It will be a groundbreaking delivery closing the loop in a cycle that turns waste into resources.

"This ultimate act of recycling shows how far we've come in developing new approaches to creating energy independence while reducing our carbon footprint,” said King County Executive Ron Sims.

The canola-based biodiesel purchase was announced last week at King County’s annual Earth Day Expo. Another part of the Earth Day celebration came two days later, when Metro and other local transit agencies, hosted a free-ride day on all buses in a three-county area.

The invitation to ride the bus was well received by both transit-savvy customers and brand-new riders. Many said they were riding on Sunday because it was Earth Day and they wanted to make a difference. And, all said they appreciated Metro sponsoring a fare-free day.

Sample canola seeds used to make biodiesel.

Metro has committed to purchase 2 million gallons of canola-based biodiesel, which will be mixed with Ultra Low Sulfur Diesel to produce a 20 percent blend for use in Metro diesel-powered buses. This will result in nearly a year’s supply for Metro.

The purchase of canola-based biodiesel will further King County’s global warming reduction goals. Metro’s use of biodiesel is expected to remove an estimated 22,000 metric tons of carbon dioxide from the air, or the equivalent of removing 2,800 vehicles from King County roadways. More than 6,628 trees would have to be planted to offset the same amount of carbon dioxide that’s being eliminated through this use of biodiesel.

Using the canola crop grown in Yakima County completes a waste-to-resources loop that starts and ends in King County. The cycle includes:

• Biosolids, a by-product of the sewage-treatment process at King County’s wastewater treatment plants, are sent to farmers to be used as fertilizer.
• Some of those biosolids are used to grow canola crops in Yakima County.
• The canola seeds are sold to Natural Selection Farms for crushing into canola oil.
• The oil is then brought to Seattle Biodiesel (Imperium) and refined into biodiesel.
• The biodiesel is taken to Associated Petroleum Products, where it is blended with Ultra Low Sulfur Diesel.
• The fuel is then delivered to Metro to fuel its diesel-powered buses.