The eyes of the world understandably are focused on the oil crisis, but another potentially devastating shortage looms large: water. The U.S. government predicts at least 36 states will face water shortages within the next five years due to rising temperatures, drought, inefficient use of resources, and increased demand from population growth and urban sprawl.
Georgia already is in the midst of an extreme drought, reservoirs in upstate New York are at record lows and Florida is far from prepared for its pending population boom. The Great Lakes are shrinking, the Sierra Nevada snowpack is melting faster each year, and researchers at the Scripps Institution of Oceanography at the University of California San Diego project Lake Mead—the primary source of water for Las Vegas—will dry up in 13 years unless usage is curtailed.
While much deserved attention has been given to improving buildings’ energy efficiency through photovoltaics, daylighting and zoned HVAC systems, the smart use—and reuse—of water plays an equally valuable role in sustainable development.
The RAND Corporation, a nonprofit research organization, estimates commercial buildings expend about 17 percent of the total public water supply in the United States.
To help curb consumption, construction professionals increasingly are seeking ways to conserve and more efficiently utilize water on both ground-up and renovation projects. New products and technologies are being implemented with calculable, exciting results.
No Excuses
Hoffman LLC, a 116-year-old planning, design and construction management firm in Appleton, Wis., is wholly dedicated to delivering sustainable projects that, whether certified or not, meet LEED Silver standards. Through its company motto, TPMg (total project management to the power of green), Hoffman infuses sustainability into each job from start to finish.
Preserving water is just the right thing to do, says Mark Hanson, the company’s director of sustainable services.
"Look at what you pay per year for water—pumping, storing, delivering," he adds. "It’s not as large as energy costs, but it’s still an appreciable cost and it’s very easy to bring that cost way down."
One way to slash water usage is through efficient irrigation systems; or, better yet, through selecting plants that thrive without an in-ground irrigation system. These types of grasses, flowers, shrubs and trees also tend to require less fertilization and care. Effective designs also manage stormwater by retaining water onsite and filtering it back down to groundwater.
"Inside a building, there are a rich set of options for lower-flow plumbing fixtures," Hanson says. "We’re routinely getting 40 percent water savings on inside water use."
Some of these options include waterless urinals, dual-flush toilets and low-flow shower heads—all of which are being adopted more regularly, according to Brewster Earle, senior vice president of energy services for Comfort Systems USA, Hartford, Conn.
Hanson says manufacturers increasingly are offering attractive, serviceable products that don’t sacrifice performance for efficiency. Price points are improving, too.
"We can deliver green projects at conventional cost. They can cost more, but it need not be that way,"” Hanson says. "I think the marketplace over time will get even more sophisticated in buying green at an affordable cost."
When it comes time to replace a building’s toilets, and low-flush versions are comparable to traditional models, “there really are no excuses for not saving water,” he says.
Of course, this doesn’t mean every possible solution is appropriate for every project. Earle says many owners are still learning about graywater and rainwater collection systems, so large-scale adoption has been slow.
Adds Hanson: "If you eliminate outdoor irrigation and cut inside use in half, is it worth the extra resources to take on another system?" He encourages designers and builders to determine the added value of taking that next step.
A Natural FitTaking that next step made sense for the Alabama 4-H Environmental Science Education Center, completed last November in Columbiana, Ala. Because the two-story, 17,500-square-foot facility teaches students about the importance of conserving resources and protecting the environment, a rainwater collection system seemed a natural fit.
In addition to a stone façade accented by wood siding and storefront windows, Davis Architects, Birmingham, Ala., designed a sloped metal roof that rises 42 feet on the north side of the building and ranges from 15 feet to 29 feet on the south side. The roof, which incorporates high reflectivity and emissivity, guides rainwater through a two-stage filtration system.
"The first stage filter is connected to the end of a typical rainwater downspout where leaves and larger debris are filtered," says Chuck Roberts, project superintendent with B.L. Harbert International, LLC, a Birmingham-based general contractor with $260 million of green building projects under its belt. "From there, the rainwater is piped to a gravity-driven 12-inch collection pipe. The rainwater then flows through a larger Vortex filter that removes any remaining debris and contaminants."
Once the filtration process is complete, the rainwater is stored in an 11,000-gallon tank from which it can be pumped into the mechanical room and redirected to the non-potable domestic water system and the fire suppression system. The non-potable system serves the toilets and feeds the exterior hose bibs.
"The biggest challenge we experienced during the construction phase had to do with the location of the tank," Roberts says. "The dimensions of the tank are fairly large—13 feet tall with a 12-foot diameter and weighing 12,000 pounds. Special care was taken to get the crane set up and the tank set without damaging any of the existing trees and foliage."
Crews were allowed only within 40 feet of the building footprint in order to minimize the impact of construction activities on the natural setting. Aiding B.L. Harbert in the process were Birmingham-based subcontractors RJ Mechanical, Inc., Fire Sprinkler Contractors, Quality Roofing and Excelsior Construction.
The $7.5 million education center—which also features waterless urinals, low-volume toilets, minimal irrigation and pervious paving for stormwater management—is awaiting LEED Gold certification. It’s designed to qualify for 45 points (only 39 are necessary for LEED Gold)—four of which stem from the rainwater collection system: one point for innovative wastewater technologies, two points for water use reduction and one point for an innovation and design credit for exemplary performance in water efficiency.
"Rainwater collection, along with water-efficient fixtures, allowed the project to obtain an 86 percent reduction in potable water use and a 92 percent reduction in wastewater generation," Roberts reports. "A typical design would use 372,993 gallons of potable water a year, but the 4-H center has cut that down to 55,493 gallons per year."
The building saves 168,366 gallons of potable water each year by using the captured rainwater to flush the toilets. Additionally, B.L. Harbert cut more than $1 million from the 4-H project’s initial budget and realized a savings of approximately 3.5 percent of the final budget.
B.L. Harbert increasingly is finding opportunities to utilize water-saving technologies in its work. Designed for LEED Silver certification, the Auburn Research Park, Building One in Auburn, Ala., will incorporate a building perimeter drain system that collects and diverts rainwater into a bio-retention pond, which in turn reduces the amount of water introduced into the facility’s stormwater system. Other features include low-volume toilets, waterless urinals and a bioswale filtering system in parking lot areas.
"Green building and sustainable architecture has certainly become more than a fad," Roberts says. "“We are seeing more and more environmentally conscious projects being built in this area, around the country and around the world."
Comfort Systems USA, a mechanical systems installer and service provider with more than 40 locations nationwide, is embarking on a new challenge to bolster its presence in the green building market.
"We have made a strategic decision to have green building expertise in each of our operations so that customers identify us with a high level of energy efficiency and sustainable literacy," says Brewster Earle, vice president of the company’s energy services operation in Hartford, Conn.
Comfort Systems USA is developing this expertise by investing in training. The goal is to have at least one LEED Accredited Professional in each of the firm’s operations.
"We provide regional workshops to support that goal," Earle says. "We had 57 employees in the first two workshops and expect similar numbers for our next two workshops to be held in the third and fourth quarter."
A month prior to the workshops, which are conducted at a LEED certified building, attendees receive a study package that serves as a primer for the LEED Professional Accreditation exam. An architect from a firm with which Comfort Systems has a good relationship facilitates each workshop, going through the study materials point by point to clarify details and discuss practical applications and administrative aspects of certifying buildings under the LEED program.
Participants also tour the LEED building to see sustainable applications up close, and personnel responsible for the operation, construction or certification of the building give presentations.
"Our intent is that this type of intensive approach of point-by-point review and discussion along with a visual tour of a LEED project will prepare our team members to understand the process and take and pass the exam," Earle says.
Training is open to most employees; so far company presidents, estimators, sales managers, business development professionals, project managers and corporate staff have participated.
Earle estimates about 40 employees have achieved LEED professional accreditation and expects that number to double by the end of the year.