Credit: © Jeff Goldberg/Esto for Ennead Architects
Since the 1970s, the federal government has spent billions of dollars on wastewater-treatment plants to bring them up to snuff, or at least to meet federal mandates. Much of this money has come in the form of Clean Water Act grants for states, municipalities, universities, and nonprofits. No amount of money, however, can change the perception that wastewater treatment belongs out of sight and out of mind.
Architects have taken up the unlikely burden of making water treatment more visible—as treating wastewater and returning clean water to users, or “closing the loop” in technical parlance, is a critical way to preserve freshwater and protect headwaters. Three recent projects of different scales demonstrate not only progress in the treatment of wastewater, but also new opportunities in the design of treatment plants.
Regulation, as it turns out, can serve as a source of inspiration. The U.S. Environmental Protection Agency has tightened regulatory limits on nutrient discharge levels, prompting municipalities on sensitive watersheds to overhaul their water-treatment procedures. For example, a nonprofit consortium of municipalities in Washington state—the cities of Lacey, Olympia, and Tumwater, as well as Thurston County (LOTT)—was required to add nutrient removal to its wastewater treatment program before discharging into Budd Inlet, part of the Puget Sound, in the ’90s; the regulations were tightened in 2005 and Budd Inlet was deemed impaired for aquatic life.
Under the new dispensation, the LOTT Treatment Alliance commissioned Seattle’s Miller Hull Partnership to design the new 32,000-square-foot Regional Services Center—which was built in 2010 and has since earned LEED Platinum certification—as part of the existing treatment plant on site. For the plant, Scott Wolf, FAIA, and Robert Hull, FAIA, converted an older lab and administration building into a state-of-the-art water-quality testing lab.
LOTT managers further decided to produce and sell Class A recycled water. Class A recycled water is treated to a high safety standard: It can be used to irrigate crops for human consumption. Their first customer for that water is the plant’s service center, which is just downstream of the plant and consolidates all of LOTT’s administration and operations staff (formerly spread out between two buildings in different locations) in one building.
Miller Hull helped LOTT install a cogeneration plant within the wastewater-treatment plant, which also serves the Regional Services Center. It takes another waste product of the treatment plant—methane—and uses it as fuel to fire generators. The cogen plant produces additional electricity and helps fire the boilers that in turn produce additional heat for the low-temperature water loop. “We recognized that there was this waste product amenity on the site such that we were able to pull off another line from that loop to serve a new children’s museum on an adjacent parcel,” Wolf says.
The services center building also houses the Water Education Technology Center (WET). WET is an interactive museum focused on water use and conservation. One computer-assisted map encourages visitors to “flush” toilets on site and see how far wastewater travels from their home to the treatment plant. “To a lot of people, water and wastewater systems are invisible—water is the 6 inches between the faucet and the drain,” Wolf says. “We’re making the invisible visible.”
On a smaller scale, the San Francisco Public Utilities Commission (SFPUC) decided that its new headquarters—still under construction in the city’s Civic Center area—should practice what the agency preaches. “We’re asking our customers in a big way to conserve water,” says Rosey Jencks, who is with the SFPUC’s Urban Watershed Management Program. “Our commissioners wanted us to walk the talk.”
In 2001, KMD Architects, working then with Stevens & Associates, had originally won a request for proposals in San Francisco to design a 227,500-square-foot public building that met LEED Silver requirements; however, the project was put on hold in 2002 as a result of the dot-com bust. In 2006, when the San Francisco PUC began looking for a new headquarters building of that same size, the project was reborn. The 15-story building, which won an AIA San Francisco 2010 Excellence in Unbuilt Design award, features built-in wind turbines and solar panels and is predicted to use 55 percent less energy than a building of a comparable size. An almost completely closed-loop water system will treat close to 5,000 gallons per day of wastewater generated by the building.
The SFPUC headquarters becomes a treatment plant in itself. The building’s wastewater is collected from throughout the building and stored in a below-grade primary tank. “That tank is really meant for screening foreign objects like plastic that people may flush down the toilets, to give them a chance to settle out,” explains KMD designer and project lead Michael Rossetto. From there, the water is pumped into the so-called Living Machine system for treatment.
The Living Machine system, which has also been installed recently at the Port of Portland, is an engineered acceleration of natural tidal wetlands processes, Rossetto says. Wastewater is piped up into a series of divided cells, or planters, containing treatment wetlands. Bacteria and microcrustaceans in the aggregate consume the wastewater products, says Rossetto, “converting nasties to non-nasties” (e.g., converting ammonia to nitrogen to nitrogen gas, completing the natural nitrogen cycle). Each time the wastewater is pumped from one cell to another, the water gets a little cleaner. “Out in the marshes, the tides go up and down, oxygenating the soil several times a day,” Rossetto says. “This system accelerates that—pumps will raise and lower the level of the wastewater in the treatment cells several times a day, oxygenating it.”
On the other end of the scale is a plant that opened recently in Brooklyn, N.Y. There, architect Richard Olcott, FAIA, of Ennead Architects has been working with the New York City Department of the Environment since 1991 on a $4.5 billion phased upgrade of nine different buildings that make up the Newtown Creek Wastewater Treatment Plant. A 53-acre site, the Newtown Creek plant treats wastewater from a staggering 1.5 million people per day, discharging the effluent into the East River. Like many older treatment plants around the country, this one (built in the late 1960s) had not been meeting Clean Water Act requirements for many years. Plant superintendent Jim Pynn explains that the plant was only removing 65 percent of the pollutant load coming into it; the Clean Water Act requires at least 85 percent of the load to be treated.
In 1990, a master facility plan was drawn up that called for a design that would bring treatment up to the 85 percent load requirement. New York City’s then-chief-architect for the Department of Environmental Conservation, Michael Cetera, recommended Olcott, James Polshek, FAIA, and Timothy Hartung, FAIA, of Ennead Architects—then known as the Polshek Partnership—as the architectural team that would work on the project with three engineering firms.
The designers are renovating the buildings on a phased schedule, as the plant must remain operational—an unusual challenge. “You can’t turn this plant off,” Olcott says. “The project has required a whole game of musical chairs where you build a part of the system and put it online, then shut down an old part and take down a building.”
The plant’s large, egg-shaped digesters, which treat the residual material that is removed from the wastewater—also known as sludge—are a signature feature of the building design. But the design for them wasn’t obvious, in particular the enclosures and catwalks connecting them. “We knew there was going to be an egg,” Olcott says. “We had to figure out what it would look like, the enclosure and the catwalks connecting the eggs.”
Today, the Newtown Creek plant is averaging removal of 93 percent of its pollutant loads—more than that required by the Clean Water Act, Pynn says. Unlike the San Francisco or Washington State projects, Newtown Creek does not produce gray- or recycled water. Pynn says that it would be extremely expensive to retrofit an older city such as New York to use gray- or recycled water.
Olcott says that designing wastewater infrastructure represents a huge opportunity for architects. “Wastewater treatment has always been a neglected part of our culture that no one wants to think about. But, one by one, these plants are all going to have to get fixed.”
In the long run, Miller Hull’s Wolf says, the ultimate goal of all new wastewater-treatment projects—and where technology will lead in the future—is water treatment and reuse. “We have the technology to do it, but the public health agencies are not quite there yet. With all of the pressures on global resources, closing the loop is going to be essential.”