In one session at the 2010 GreenBuild, Greg Sparks, Port of Portland, Will Kirksey, Worrell Water Technologies, and Doug Sams, Zimmer Gunsul Frasca Architects outlined how the new Portland port headquarters building applied a cutting-edge “Living Machine” to treat wastewater on site and reuse for toilets and building cooling systems. Jon Gray, who works for the Oregon Sustainability Center, which will soon move into the first large-scale net-zero “Living Building” in the U.S., then described another iteration of the Living Machine.
The Port of Portland is a public agency that views itself as a key driver of economic activity in the city. Also, its environmental programs have made it very progressive on this front — the port is a founding member of the climate registry, top 50 purchaser of green energy in the U.S., and part of the EPA’s climate leadership program.
On water conservation, the port aims to conserve, sustainably reclaim and reuse water, limit its potable water use, and store stormwater. To conserve water, it uses dual-flush toilets, irrigation controls, and the Living Machine. To mitigate its own development the port constructed a new wetland.
New Headquarters Building’s Living Machine
The new headquarters, which brings all employees into one large building with three floors of offices and seven floors of parking space, was designed to help create “one port.” The building’s Living Machine is an ”ecosystem approach for treating wastewater,” said Kirksey, a civil and environmental engineer. “With next-generation technology, we can actually return to nature.” The system is made possible by combining “ecology, information technologies, and engineering.”
The port building captures water from faucets, showers, and toilets, which is then funneled into the system. “There’s a screen that captures large particulates, then the Living Machine does its work.” Influent blackwater or greywater is sent to a primary tank, then the ”tidal wetland cells” which contain a gravel medium that harnesses micro-ecosystems (micorganisms, snails, and other critters) and cleans the water. “The cells fill with water and remain wet for 45 minutes, then drain.” The water drains out into “a set of polishing cells” that trickle down into the reuse systems. Treated water is sent to toilets and AV cooling systems, improving overall building water efficiency by 70 percent, said Sams.
Kirksey said the system was also more energy efficient than aerated wetlands, which require higher-maintenance. Another plus: the portland facility was built on-site with local labor. “This is not a factory-built system, so it creates local green jobs.”
The Living Machine and Building Systems
The machine was selected because the port needed to meet its own stringent environmental requirements. (The building eventually went on to certify as LEED Gold). For example, water use couldn’t exceed annual rainfall on site. Local native plants needed to be used. Surrounding air quality needs to be high. Energy use needed to equal on-site solar capacity. Also, the site could only incorporate non-toxic, recycled, reused or renewable materials.
The average rainfall in the area is 36 inches, which means the site needed to capture 12 million gallons each year. The architects explored a variety of options, including capturing water on site and creating a distribution network that can drive water to the rental car washing facilities (which use 14 million gallons per year), the CUP systems (which use 8 million gallons per year), as well as the building (estimated at 1.45 million gallons per year). Sams said “we couldn’t afford to do this. We would need a huge storage tank and there was no place to bury this on site.”
Instead the architects decided to add a set of green roofs that store the annual rainfall on site (but don’t transfer the water to those water use systems), and 1,500 square feet of the Living Machine system, 700 square feet of which is in the indoor lobby and the rest at the front of the building.
To deal with odors from the machine, the team had to install odor cleansers. “We couldn’t have strong odors entering the lobby.” Also, there were some challenges in finding plants that could be used given the port has a “restrictive list.”
Adding the Living Machine to a Living Building
Grey said the Oregon Sustainability Center will be the largest net-zero “Living Building” in the U.S. when its completed (see earlier post). The seven-story building will house public, private, and non-profit organizations focused on “growing the green economy” in Portland. The building will produce 100 percent of its energy on site and use the Living Machine integrated water re-use system to capture, cleanse and create potable water on site.
The rooftop Living Machine will be 1,600 square feet. Translucent solar panels will cover parts of the system, creating addtional efficiencies.
“Some 20 percent of the effluent needs to be removed from the Living Machine or it will poison the plants,” said Grey. So, the idea is to move this mineral effluent to bioswales along the front of the building, which can then return cleansed water to the acquifer. “Also, I can’t discharge any water on site, so the bioswales will also deal with excess rainwater.”
The total rain collection area in the building’s green roofs and swales is expected to be 22-27,000 square feet, which will capture more than 300,000 gallons of water. While the green roofs and swales will catch much of the rainfall, Portland has variable weather so a new approach to stormwater management is needed. Some seasons, the city gets a lot of rainfall and during others, the city is very dry. So, underneath the building, there will be a 250,000 gallon stormwater catchement cistern.”We had to create a storage tank sized using the five driest years in the past 50.”
In all, the new building is expected to achieve 100 percent water efficiency gains through the Living Machine, new fixtures, and other greywater reuse. Grey said the big plus of doing this innovative water reuse project in Portland was that the “regulator wanted to cooperate. We also consulted with the local health department and they want to make this work. In how many places can you say that is true?”