Page 32 - Green Builder May-June 2017 Issue

CREDIT: GBD ARCHITECTS

Going with the flow. Stormwater planters and a water feature that uses treated rainwater help create a peaceful atmosphere in an urban setting.

from the Oregon Department of Environmental Quality (DEQ) and
one from the City of Portland Bureau of Environmental Services.
“It was invaluable to have that sort of clarity right away,” says Project Stats
Muñoz.
NAME: Hassalo on Eighth
CREDIT: BIOHABITATS
OWNER/DEVELOPER: American Assets Trust
THE NEW NORMAL
The onsite treatment system has a name: NORM, or Natural Organic GENERAL CONTRACTOR: Turner Construction
Recycling Machine. A multi-stage treatment train uses natural ARCHITECT: GBD Architects
biological processes to treat 100 percent of the wastewater from LANDSCAPE ARCHITECT: Place Studio
all three new buildings (see “How NORM Works,” p. 19). The most NORM TEAM LEAD: Biohabitats
prominent feature is the trickling filters, which are housed in four GREEN ROOF INSTALLATION: Teufel Landscape
red tanks at the north end of the pedestrian corridor. Wastewater is GREEN ROOFS: Columbia Green Technologies
pumped to the top of the filters, where it flows—or “trickles”—down MECHANICAL/ELECTRICAL/PLUMBING: Glumac
media that supports bacteria growth. The bacteria feed on nutrients
in the wastewater.
From there, the wastewater flows through a pair of tidal wetlands. groundwater via recharge wells located next to the trickling filter
Every two hours, as the first cell fills, the second empties. This ebbing tanks.
and flowing promotes bacteria growth on the gravel; the bacteria and The system is monitored continuously and must meet strict
plant roots take up nitrogen and phosphorus from the wastewater. criteria for turbidity (cloudiness) and pathogens. If turbidity exceeds
The tidal cells are 14 feet deep. standards, the treated water is automatically sent to the city sewer
“This is unique,” says Muñoz. “The cells are much deeper than the instead of to the reuse tanks. The system also monitors nitrogen
typical constructed wetland.” levels to ensure treated wastewater does not contribute excess
Next, the wastewater flows through “wood chip” wetlands, a nutrients to the groundwater.
denitrification reactor and a second set of tidal wetlands. Finally, NORM saves energy, improves water quality and cuts potable
the water is filtered and disinfected with UV light and ozone before water use by over 20,000 gallons per day. But the system also makes
being sent to the reuse tank. sense economically.
The wastewater is treated to Class A standards, as defined by The project has meters installed which monitor water coming
the Oregon DEQ. This most stringent classification also allows the in and the water coming out of the buildings, to prove they aren’t
most uses. At Hassalo on Eighth, the treated water is used to flush contributing wastewater to the sewer system. This way, Hassalo on
toilets, irrigate landscaping, resupply the cooling tower and recharge Eighth avoids sanitary sewer charges.

30 GREEN BUILDER May/June 2017 www.greenbuildermedia.com

28-33 GB 0517 Hassalo on 8th.indd 30 5/25/17 11:07 AM