New sidewalks laden with hundreds of crushed toilets—yes, toilets—have earned the world’s very first Greenroads certification in Bellingham, WA.
The pavement material, called Poticrete (potty crete), was used to build the Meador Kansas Ellis Trail, which spans six blocks of downtown Bellingham and represents the final link in the popular Whatcom Creek recreational trail.
Photos: City of Bellingham
|The Meador Kansas Ellis Trail has earned the world’s first “Greenroads” certification.|
The Poticrete project is the first to be awarded certification by the Greenroads Foundation, a nonprofit, third-party corporation established in 2010 to oversee the Greenroads Rating System for sustainable road and bridge design.
Poticrete earned Greenroads Silver certification, whose standards “represent a significantly higher level of sustainability than typical road projects of today,” officials said.
The Poticrete material used more than 400 toilets that were diverted from a landfill, crushed and then tested as an alternative to virgin aggregate. Test results showed that Poticrete met city requirements for flatwork concrete.
The final mix contained about 20 percent crushed toilets by volume and represented about five tons of material diverted from a landfill and into a sidewalk, the city said. Crushing the toilets cost about the same as using virgin aggregate from regional gravel pits, officials said.
Beginning in August, 2011, the city used 250 square yards of Poticrete on its Ellis Street as part of the $850,000 trail project. The project also used asphalt with 30 percent recycled content and recycled concrete aggregates, porous pavements and other environmentally conscious elements.
The Bellingham Housing Authority, Dawson Construction, and Cowden Gravel and Ready Mix Inc. collaborated on the project. The contractor was Larry Brown Construction (LBC).
The world’s first certified Greenroad represented a milestone for both Bellingham and the Greenroads Foundation, officials said.
“Working with the Greenroads system has helped us to add key content to our specifications for more sustainable project delivery, as well as getting our department to design more holistically,” said Freeman Anthony, Bellingham’s project manager.
|Hundreds of crushed toilets are mixed with the other components of Poticrete, a new pavement material pioneered in Bellingham, WA.|
City officials said they hoped to revise the municipal concrete specification to allow the use of similar materials, including crushed concrete, for flatwork concrete aggregate in city projects.
‘Not Just a Dream’
For the foundation, the certification capped a five-year process to research, develop and implement a sustainability rating system for the roadway industry. The Greenroads Rating System began as a research project at the University of Washington in 2007 and has involved more than 20,000 hours of work and more than 100 roadway project case studies since then.
“Sustainable roadways are not just a dream,” said Jeralee Anderson, the foundation’s executive director. “This certification means that Greenroads’ five years of research and development has finally become a reality.”
Anderson called the Poticrete project “a great example of the mission of the organization” that “further defines the practical steps that can be taken to green our roads—both nationally and internationally.”
An international standard, the Greenroads Rating System is a collection of sustainable roadway design and construction best practices that address water, environment, access, community impact, construction practices and materials.
Project teams must satisfy 11 Project Requirements for a roadway to be considered a Greenroad and may choose from 37 Voluntary Credits. The foundation then assigns a project score that translates to one of four certification levels: Certified, Silver, Gold and Evergreen.
Globally, 12 projects are currently pursuing Greenroads certification. Those projects include new construction, reconstruction, overlay and bridge projects.
“The Greenroads Rating System can be used to help manage, improve and communicate sustainability,” said Steve Muench, a Greenroads founder and board member. “It represents an independent verification of sustainable features that truly matter and make a difference.”