How to Conduct a Water Audit to Save Your Facility Money

Cutting back on water usage can seem like an overwhelming task. Where do you begin? What do you prioritize?

The most effective way to achieve water efficiency is to conduct a comprehensive water audit to identify potential areas of improvement. We've enlisted the help of experts to simplify the process into a few key steps and identify common issues along the way.

Sustainable investigating

The first step in any water audit is to gather as much information as you can about the site, including past water use patterns. "I consider doing an audit a little bit like you're a detective," says Peter Mayer, principal and founder of Water Demand Management, a Boulder, Colo.–based engineering consulting firm specializing in water resource management. "You're going to some place you don't know a lot about, trying to understand where water is used and how it can be used more efficiently, and what can be done in terms of hardware and fixture modifications and changes."

The discovery stage should go well beyond looking at a water bill for annual consumption. It should take into account patterns of use (when water demand peaks and when it's lowest), the building's occupancy rate and density and distribution of occupants, and how and where water is used in the facility. Gathering several years of monthly usage data is ideal.

Unlike an outside expert, an on-site facilities manager or building engineer conducting an audit may already be privy to many of these details, but some sleuthing or information gathering is likely still in order. Water usage patterns can easily be decoded by walking down the hall to accounts payable to talk seasonal fluctuations in billing, interviewing a surgeon about water use in different medical procedures, or roaming the campus with the grounds crew to discuss irrigation.

Trust but verify

After determining usage patterns, the next step is to walk through the facility and inventory all fixtures, looking for leaks and inefficiencies, such as unnecessarily high flow rates. Most commercial fixtures have flow rates etched onto the product, as mandated by code. However, what you see isn't always what you get, points out Bill Hoffman, principal and founder of Water Demand Management, an engineering consulting firm focused on demand-side management of water resources in Boulder, Colorado. A toilet might be labeled as a 1.6-gpf fixture, but if someone retrofitted it with the wrong valve, it could suddenly become a 3.5-gpf toilet. His rule of thumb: If it takes more than three seconds to flush, it's more than a 1.6-gallon toilet.

Inexpensive and low-tech ways of checking flow rate accuracy include flow meter bags, which are available online, and the old fashioned bucket-and-stopwatch test. However, installing actual flow meters is a higher-tech and more dependable approach. It might be inefficient—or even impossible—to test every single fixture in a facility. In a 200-room hospital, for example, Hoffman would test 5 to 10 percent of rooms to get a sense of overall efficiency. During this testing, he advises, also note any leaks or running toilets to fix.

Walk through the facility and inventory all fixtures, looking for leaks and inefficiencies

Procedures and processes

In commercial kitchens, it's not enough to measure flow rates—you should observe how kitchen or building staff utilize the space. Garbage disposals are notorious water guzzlers, Hoffman says, with water flowing into them at rates of 6 to 10 gallons per minute. Mechanical strainer systems are much more efficient and use only about two gallons per minute. It's also important to double-check frequently used fixtures like pre-rinse faucets for leaks.

Kitchen hand-washing sinks should be fitted with faucet aerators to eliminate waste. Conversely, large industrial sinks, which lack aerators, should not be used for hand-washing. "Thawing stuff out in the sink [with water] should be discouraged in all cases," Hoffman adds. Running water over an item to thaw it out can cause water bills to rapidly escalate.

Limit garbage disposal usage; install faucet aerators

In many cases, however, eliminating inefficient processes can be as effective in reducing water waste as replacing fixtures. For example, cleaning procedures can make or break efficient water usage in the kitchen. Hoffman recalls one restaurant using a high-pressure spray to wash floors near clean dishes—and having to rewash dishes frequently as a result. "Use common sense when cleaning," he says. "Don't let water overflow," and don't overspray.

The final step of an effective water audit is to create a new water budget for the site. Fixing leaks and problems, investing in low-flow fixtures and appliances, and implementing smarter procedures are all effective ways to reduce consumption and stay within budget.

A path forward

A variety of tools and resources are available to help in the construction of an efficient water plan and budget. Start reducing wasted water with these resources:

The American Water Works Association published a manual offering guidance on water audits, leak detection and loss control programs. Buy it here.
The Water Research Foundation put out this booklet on Commercial and Institutional End Uses of Water, published in 2019.
Sometimes a fresh set of eyes also can provide helpful guidance or validation of findings. Commercial water savings experts are available to conduct an audit or to serve as a guide when analyzing findings. "A facilities manager doing it himself may not have the perspective of what's going on at other buildings," Mayer says. "They may be using 10 gallons per square foot or 30 and may not know if that's good or bad." Experts can offer valuable industry perspective.