Unless your commercial building has a cooling tower, most of the water used there is in the loo. According to Jim Keller, partner for Sustainable Design at Gausman & Moore, an engineering firm in St. Paul, Minnesota, about 60% of water used in an office building goes through “restroom plumbing.” Here’s how to save water while people are, ahem, producing it.
As an added benefit, all of these technologies—with the exception of the waterless urinal—are good to have at home, too.
Low-flow faucet aerators: The easiest way to conserve water is to limit the amount that comes out of the faucet. People should wash their hands in the loo, but aerators let them do it with up to 50% less water than conventional faucets. Conventional faucet aerators deliver 2.5 to 5 gallons of water per minute. Low-flow aerators deliver 0.5 to 1.0 gallons. Low-flow aerators are easy to install and have a swift payback period.
High-efficiency and ultra-low flush toilets: Both of these use about half of the water of conventional models, averaging 1.6 gallons per flush instead of 3.5. Ultra-low flush models are the more efficient of the two, using only 6 of the tank’s 13 liters per flush. An ultra-low flush model can be fitted with a dual-flush valve (see below) for even greater efficiency.
Dual-flush valves: Dual flush valves save water by offering two different water closet options: one for liquids and the other for solids. The real saving comes in the liquid option: it uses 0.8 gallons per flush, as opposed to 3.5 in a conventional commode or 1.6 in a high-efficiency version. Dual-flush valves can be easily retrofitted onto existing toilets.
Waterless urinals: Even though waterless urinals were introduced as early as 1992, they’ve since been refined, and interest in them has grown as building engineers and managers become more conscious about conserving water.
Waterless urinals use a sealing liquid—typically an oil, which is less dense than urine—that lets urine flow through and sink beneath. The oil traps any odor. There are two types of waterless urinals, one that uses a cartridge, which encases the sealing liquid, and non-cartridge systems, which put the sealing liquid directly into the drain hole. Waterless urinals don’t need piping, flush controls, or sensors. They greatly reduce maintenance and installation costs.
Despite the benefits, many people—plumbers, building engineers, and lavatory users—are resistant to the idea of waterless urinals. Plumbing codes in many cities prohibit their use. Success in installing a waterless urinal is likely to require 1) big increases in water costs; 2) significant commitment to water conservation; 3) education on the part of anyone who uses the lavatory.