Portland’s porous pavement a prize

By Public Works Magazine
Portland, OR (January 1, 2007)- Sustainable design has been a buzzword for the past few years, but the Port of Portland (Ore.) has taken it to a new level with a porous pavement project. Built in 2006, the Port installed 35 acres of porous asphalt, along with 15 acres of impervious pavement, at one of its automotive-import facilities. The Terminal 6 project provides a model of environmental stewardship and smart business, balancing benefits to the community, the economy, and the environment.

In combination with the porous asphalt pavement, rain gardens in swales can manage 100 percent of a site’s stormwater.- Matt Rogers, Century West Engineering.
At an estimated construction cost of $6.45 million, the developed area will save the Port money in the short and long run. The agency saved $250,000-and nearly a year of time-on its National Pollutant Discharge Elimination System permit, which regulates and keeps tabs on stormwater runoff for a given area. “Since there were no assets to build underground, it was faster and cheaper,” says Dave Dittmer, engineering project manager at the Port.
The Port also receives a discount on the city’s storm sewer fee for using porous pavement. The area has unique sub-surface conditions; it is mostly sand, which allows for better infiltration. This sub-surface eliminates the need for underground piping systems to remove the stormwater runoff-another cost savings.
Maintenance includes sweeping the area a couple of times per year, which is typical for porous pavement. Since the facility is for new cars, there are no fluid leaks to worry about. “This is a unique situation,” Dittmer says. “It’s not common for other public works departments to have a situation like this where no containment is needed.”
Porous asphalt allows for a great deal of infiltration, providing onsite storm-water management and reducing storm surge into adjacent waterways.- Matt Rogers, Century West Engineering.
The Oregon chapter of the American Public Works Association recently awarded the project a Julian Prize for Sustainability. The Port hired Portland-based Century West Engineering and landscape architecture firm GreenWorks, along with stormwater management firm Cahill Associates, West Chester, Pa., to complete the project.
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