The U.S. Geological Survey estimates that water lost from water distribution systems amounts to 1.7 trillion gallons per year. That’s a national cost of $2.6 billion per year.

MORE THAN A DRIP: Between California's drought and Flint's contaminated water supply, water loss prevention is crucial and calls for audits to track just where that water usage is flowing.

Setting the guidelines

A number of states—Georgia, Texas, Tennessee, California, and member states of the Delaware River Basin Commission—have instituted guidance or requirements in recent years for water loss reporting. Initially, only Georgia required comprehensive data validation, which includes validation by a third-party.

In October 2015, lawmakers in California passed legislation that requires all state urban water suppliers to conduct annual water loss audits and submit the results to the Department of Water Resources for public review.

“Water audits are a first step in developing a comprehensive water loss control program,” says Rob Renner, CEO of the Water Research Foundation (WRF). “Therefore having sound audits is of the utmost importance to both the water industry and local communities they support.”

Gauging water’s efficiency

However, many water suppliers have not been provided guidance on how to validate water audits, nor have they been provided strategies for managing leakage. Fortunately, innovative research has emerged that will help water utilizers better understand the sources of their leakage losses, analyze their economic intervention strategies, and validate water audits.

“‘Water audits are a first step in developing a comprehensive water loss control program.’”

Anyone attempting to manage leakage must start by performing a “top-down” water audit, which calculates water losses, as well as water provision that did not generate revenue. Water industry groups recommend using a relatively new, top-down water audit that is very thorough.

However, research of the first wave of top-down water audits recently found that more than 20 percent of audits present an implausible water loss scenario, suggesting that the data may not be accurate. The research showed that more training and education is needed to improve confidence in water loss reporting.

Keeping better track

In response, WRF is working on a guidance manual that will help utilities and regulatory entities double check or “validate” the water audits to ensure that realistic results are reported. The foundation has also created an innovative tool that helps water utilities understand leakage even further. Leaks from the distribution system include main breaks and then the less obvious slow leaks and weeps from cracks in pipes or joints. Some of that leakage can easily be found because it surfaces to the ground level. Leaks that don’t surface— typically smaller flowing leaks—can run unseen or undetected for long periods.

Some leaks can be detected using acoustic equipment but that doesn’t work in all situations. For example, acoustics don’t travel well along plastic pipes. Utilities can also reduce leaks by optimizing their pipe pressure, such as lowering it during low use.

“The hope is that this new approach will allow utilities to employ a proactive rather than a reactive approach to leak management,” sums Renner. “Doing so will not only result in financial savings, but also a more cost-effective and efficient consumption of our valuable, and finite, water resources.”