Commercial water use last frontier in conservation

Jun. 21—As New Mexico's climate grows hotter and drier, it will be vital for commercial and municipal users — the biggest water consumers — to be more efficient, water experts say.

That can be achieved through conservation measures, some as simple as turning off a hose and others requiring a hefty investment in systems that capture, filter and reuse water.

It all starts with thinking differently about how not to waste water, a resource that is growing more precious in the arid Southwest, two experts said Thursday at the Next Generation Water Summit in Santa Fe.

One way to greatly improve water conservation is to install systems that can help achieve net-zero water use in public buildings, said Shayla Woodhouse, a project engineer for Biohabitats.

She was referring to the concept of balancing water use and supply, while at the same time not degrading water quality. It's similar in principle to net-zero energy, in which the carbon emitted doesn't exceed the amount removed from the atmosphere.

The idea is to return as much or more water than was used to the watershed with no pollutants that can cause harm downstream, Woodhouse said. Making a reasonable effort at net zero will enhance important water resources in a changing climate, even if a user doesn't reach the ambitious goal, she said.

"We are seeing megadroughts," Woodhouse said. "Reservoirs are dropping. Having those systems can overcome those climate events."

An incalculable amount of water is lost in the network of aging pipes and collection systems, she said, so it's crucial to install infrastructure that collects, treats and distributes water more effectively.

One way is to combine old and new techniques, Woodhouse said.

She showed a slide of traditional methods, dating back hundreds of years in New Mexico: waffle gardens, acequias, adobe construction and rainwater collection. These age-old models that use the landscape and nature to enhance water delivery and energy efficiency can be incorporated into modern net-zero systems, she said.

Rainwater is key to reaching net zero in the Southwest, whether it's capturing it on rooftops or in fields, and then storing it in cisterns, she said. It also offers the chance to achieve "net positive," or giving more to the watershed than was taken, she added.

Woodhouse discussed several projects in the West in which elaborate systems installed in public buildings bolster water reuse.

At a building in Portland, Ore., that houses Pacific Architects and Engineers, a multifaceted system is at work. It drains water from between rooftop solar panels to a 7,000-gallon cistern, which then pipes it as potable water to sinks and showers.

A second-stage system diverts the water draining from the sinks and showers, known as gray water, to irrigate vegetation and flush toilets.

At the federal courthouse in Albuquerque, the emphasis is more on landscaping, Woodhouse said. The purpose was to transform the concrete, turf-heavy ground to a more vegetative surface tied to rainwater systems, she said, which include swales, rock gardens and biofiltration beds.

Aside from conserving and reusing water, this natural filtering offers ecological benefits, Woodhouse said. "So by cleaning that water before it leaves the site, we're protecting our downstream resources and protecting our watershed."

Conserving and recycling water gives people the sense of doing the right thing, both for the environment and their operations, said Michelle Maddaus, president of Maddaus Water Management, based in California.

Large-scale water use was traditionally put into three categories: commercial, industrial and institutional. In recent years, it's been broken down into many subcategories, such as hotels and restaurants or specific facilities within an institution, she said.

Maddaus presented a half-dozen examples of how her firm assisted large entities in conserving water.

At Salt Lake City, a team found three operations with enormous water waste and advised how to fix it.

Among the findings were malfunctioning cooling towers that needed to be upgraded or replaced. They were losing an estimated 4 million to 7 million gallons of water per year.

Another was firefighters spraying 2 million to 4 million of gallons of water onto the ground yearly during training. Crews began spraying the water into large truck containers, where it could be captured and recycled.

The third culprit was at a fleet car wash, where the hose was set to trickle water nonstop to avoid the water from freezing, even during warmer months. The solution was to store the hose in an insulated container to prevent freezing.

Maddaus spent much of her presentation giving advice to consultants and others on how to sell water conservation to large-scale users.

One way is to clearly lay out the benefits of cutting waste, she said. Another is to make a proposal as simple and accessible as possible, she said, recalling how the 20-page reports and in-depth analyses her firm diid two decades ago was off-putting to water managers.

Guiding them to incentives, especially grants, can inspire them to improve water use, she said, but it's also necessary to point out regulatory hassles they can avoid.

Reusing water is important but only part of the equation, she said, noting that a 20-year project her firm was involved in at Stanford University employed a lot of water-recycling systems.

"Reuse is moving forward, it's getting some attention," Maddaus said. "It's always easier to do it when you first build a facility than to do retrofits."

Woodhouse said systems designed to reuse water, especially with a net-zero goal, can be complex and expensive. On a smaller scale, they can be as simple as installing cisterns, new pipes and basic filtration.

Adding the systems to commercial buildings requires owners or public officials willing to make the investment, Woodhouse said. Regulatory barriers also must be reduced or removed to encourage the upgrades, she said.

With the climate changing, the political will seems to be shifting to foster net-zero efforts, she said.

"I think it's leaning in that direction," Woodhouse said.