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Navigate sustainability challenges to bring value to clients

Portland, Ore.’s Twelve West, designed by ZFG Architects, incorporates a graywater system that filters rooftop stormwater runoff and mechanical system condensation for fire suppression, green-roof irrigation and 90 percent of office toilet flushing. The city’s reduced systems development charge paid for 90 percent of the system’s initial cost.

Photo by Eckert & Eckert.

Your clients may be changing their approach to green building, but the trend toward sustainability is here to stay. According to study results released by Turner Construction Company last fall, 50 percent of respondents are pursuing LEED certification, and green initiatives remained strong across the board. “Overall, sustainability goals are high,” remarks Michael Deane, Turner’s vice president and chief sustainability officer. “It’s in the professional’s best interest to get educated and promote water efficiency as more people are realizing water is a finite resource.”

Water-efficiency measures sometimes get value engineered out of projects because initial costs become too high and owners prefer a quick payback on investment. That’s where your expertise can shine. Water-efficiency goals can be accomplished through a variety of measures within the client’s budget,from low-flow fixtures to state-of-the-art blackwater systems.

Combining strategies,such as graywater treatment systems that capture rainwater for reuse and divert it to low-flow fixtures,can produce synergies, Deane says. “By leveraging systems to conserve water, engineers deliver both financial and sustainable benefits.”

For example, at the University of Washington’s Seattle campus,the new Mercer Hall will collect rainwater and heat it with a solar hot water system for laundry facilities that serve 900 students.

“Technologies have gotten better,” asserts mechanical engineer Matthew Ferguson, P.E. of Syska Hennessy Group in New York. “New sewer lining membrane technology reduces first costs, and self-sustaining decentralized engineered systems that utilize pumps and organic matter to treat the affluent have smaller footprints than a septic system,” he notes. In fact, the Flemington racecourse in Melbourne, Australia, uses localized filtration of sewage with standard membranes that extract water for landscape irrigation.

Some engineering firms still conduct a great deal of LEED projects, since some agencies and institutions mandate the sustainability certification. That’s true of Glumac’s Portland, Ore., office, according to Geoff Winslow, P.E., senior associate. He specifies low-flow fixtures as a matter of course and sees only occasional challenges when retrofitting older buildings with oversize pipes. “With right-size pipes and steeper slopes, the early challenges with low-flow fixtures are disappearing,” he says.

Manufacturers are also currently delivering much higher-performing low-flow fixtures, and the industry has learned that increased slopes can have a significant impact on the fixtures’ success.

Where’s the Money?

Creative approaches can show your clients where to find the funds to retain water-efficiency measures in their projects by offsetting initial costs and offering a faster return on investment. Factoring rising water costs into cost-benefit analyses, for example, can shorten the payback timeline. Deane says that the increase in municipal water costs over time reduced a graywater project’s payback from 10 to seven years in one 350,000-square-foot New York project.

Winslow notes that system development charges can garner savings. For example, the city’s initial system development connection fee was dropped by approximately $205,000 at Twelve West, a mixed-use high-rise in Portland, thanks to water-efficiency measures. Those savings covered 90 percent of the rainwater collection system’s initial cost. “If you can tell the city you are going to save a certain number of gallons of water annually, their reduced fee often pays for much of the system upfront,” Winslow explains. “But be aware that they assess your water bill after a year or two and will require the full fee if your savings aren’t as promised.”

Another way to save money is to capitalize on project requirements. The mandated fire-suppression tank in the basement of a commercial Portland retrofit was increased in size to 140,000 gallons to supply virtually all toilet flushing and irrigation.

Analyses show graywater and blackwater treatment systems cost about the same, which can lead owners to aim higher. Ferguson says owners of The Solaire apartment building in New York City opted for a 25,000-gallon-per-day blackwater recycling system that cuts potable water needs in half and reduces wastewater discharge by 56 percent.

The building uses plumbing designed to accommodate graywater separation and an onsite blackwater treatment system that recycles 100 percent of the building’s wastewater for use in cooling towers, toilets and landscape irrigation.