The city of Bothell was awarded two certifications from Greenroads at the Dec. 8 Bothell City Council meeting for implementing environmentally sustainable practices in the Crossroads and Multiway Boulevard construction projects.

Greenroads is an independent nonprofit which cities hire to monitor and certify projects. Certification can lend validation to green policy commitments the city makes, as well as helps them monitor sustainability milestones such as using recycled material or using long-lasting materials, Greenroads director Jeralee Anderson said.

“With a little bit of an up front investment, there’s a lot of payback,” she said.

Bothell entered into construction with the goal of becoming certified, Anderson said, which made it easier for the Crossroads project, encompassing State Route 522 improvements, to receive a Silver rating. The boulevard along State Route 527 received a Bronze rating.

Anderson said both projects were different, and both scored highly as no project to date has gotten a Gold or Evergreen certification.

The Crossroads project scored 43, only three points below the highest ranked project statewide in Kirkland.

“It’s still really difficult to get certified, it’s a major, major milestone for the city,” Anderson said.

Scores are calculated by receiving points in categories ranging from environment and water guidelines to materials used and pavement technologies.

Some positive developments included opening up, or ‘sunlighting,’ the fish-friendly Horse Creek after 50 years of it being buried.

Another was installing water runoff filtration systems using trees planted in soil under the storm drain. As water runs into the drain, it is slowed and cleaned as it passes through layers of soil, and toxins are sucked out by the planted tree.

The water then drains into underground holding chambers where it is slowed once again and allows contaminants to settle in a series of tiered pipes and vats.

“You don’t really think about roads as something that can clean water,” Anderson said. “The road itself is performing an environmental function.”

For the boulevard project, points were awarded for water filtration as well as incorporating mass transit design. Bus lanes which facilitate and ease public transit count in the city’s favor.

Recycled asphalt makes up 20 percent of pavement on the Crossroads project, which is anticipated to last 40 years.

A one mile stretch of single-lane road, Anderson said, requires enough energy to construct as it would to power 100 homes for a year. Using recycled material, she said, saves upwards of 20-homes-worth of energy.

LED lights along the road also save some energy.

The city will be seeking certification in upcoming projects, such as the Downtown Revitalization Phases Two and Three, Anderson said.

The Crossroads project began in 2010 with the demolition of 14 buildings as the city embarked on a mandate to revamp downtown Bothell.