Whether decision-makers consider it ultimately attainable or not, there is something positive to be said about striving toward ‘net zero leakage’ in water distribution systems saddled with high non-revenue-water (NRW) losses. The key is taking affordable steps — like those described below — toward identifying and mitigating the most egregious water loss locations in a distribution system, based on readily accessible data.

Take Stock Of The Situation

Water loss that is not monitored cannot be measured. And if it is not measured, it cannot be managed efficiently. But don’t let ‘perfection become the enemy of good’. With increased concerns about water scarcity and the cost of water, and with affordable monitoring options that can be employed selectively, now is a good time to focus on water leak data collection that can have both immediate and long-term benefits. Look for incremental steps that can help utilize limited resources more efficiently and whittle down NRW loss rates on the way toward net zero leakage.

The concept of reducing water losses has been advocated by the International Water Association for some time, and various water distribution companies in Europe have already taken steps toward monitoring it. But much of the U.S. and the rest of the world still has plenty of potential for addressing the interrelated issues of water scarcity, revenue loss, and capital budgets through better control over NRW losses attributed to leaks. Having the data to quantify an economic level of leakage (ELL) enables utilities to make more informed decisions on water losses and leak repairs, even if the ELL changes.

One of the biggest barriers in the migration toward net zero leakage is a lack of urgency driven by fears that the solution can be more costly than the problem. Perhaps that is a reason why the most recent AWWA Executive Report on the State Of The Water Industry cites aging infrastructure as the #1 concern, yet ranks water loss down at #20.

As with so many other managerial decisions in utility operations, the key comes down to the affordable collection of appropriate data.

Divide And Conquer — Identifying Biggest Problems, Quickest Solutions First

The first steps toward minimizing water loss are knowing:  

a.) that water is being lost,

b.) how much of it is being lost, and

c.) where it is being lost.

Monitoring water inputs vs. water consumption on an area-by-area basis is a good way to identify the most problematic areas where informed repair vs. replace decisions can result in the most financially viable water and cost savings. Gathering key distribution system operating data through appropriate smart water and IoT investments in flow monitoring, pressure logging, and data management systems can provide the insights needed to lower water losses incrementally, step by step, en route to a net zero leakage goal.

But don’t expect to achieve total net zero leakage in one fell swoop. Small steps that can pay for themselves along the way are a more realistic approach. Those savings include both short-term loss reduction of treated water and long-term savings on treatment chemicals and energy spent by continuing to pump treated water through unrepaired leaks.

Finally, do not expect to solve all leakage problems by using just a single technology alone (i.e., leak detection, flow metering, or pressure monitoring). Analyzing interrelated flow and pressure data in modeling systems — especially with respect to their impacts on aging infrastructure — can illustrate cause-and-effect relationships. That can help in refining ideal monitoring locations and in providing a basis for conducting a water balance to quantify NRW losses.

Even a basic district metered area (DMA) approach using highly accurate, easy-to-retrofit flow meters (Figure 1) can empower some simple strategies that can be applied for better quantification of water use:

• Establish Better Baselines, Better Understanding. Using just a few well-placed flow meters in small utility systems (Figure 2) can help to establish baseline consumption during overnight hours. A high nocturnal baseline flow can indicate where to deploy water loss technicians to search for active leaks. Sharp peaks in flow during daylight hours can indicate where utility analysts might want to study consumer behaviors to spot exceptional consumption patterns in that area.

• Spot Exceptional Usage. By analyzing smaller segments of the overall system, it is practical to analyze per-capita consumption rates, by dayparts, in different areas of a city. This can spur further study to determine whether that water volume is due to leakage or to consumer practices (e.g., watering lawns) that might need to be managed more closely during periods of water shortages.

• Ease The Strain On Aging Infrastructure. Comparing system pressures against flow demands can identify when and where elevated pressures are putting unnecessary stress on aging infrastructure and forcing an extra volume of water through existing leaks. In many cases, those pressures can be reduced at least part of the day without noticeable impact on consumer satisfaction.

Figure 1. Easy-to-retrofit metering solutions that can be hot-tapped into operating water distribution systems without shutting down or dewatering the system make it easier to create district metered areas (DMAs) as a retrofit application. This download demonstrates how that makes is easier to obtain the flow measurement where it is most needed in a water distribution system.

Figure 2. Adding IoT-ready, flange-mount, full-bore electromagnetic (mag) meters compatible with popular communications protocols — such as Verizon, AT&T, Sensus, and Itron — to new or upgraded areas of water distribution infrastructure can help even small utilities set up DMAs to identify NRW losses.

Make NRW Loss Reduction A Team Effort

A quick, economical front line of defense against water loss is to heighten public awareness and involvement. Educating customers on the economic relationships among leak reporting, utility efficiency, and consumer water rates can motivate them to report visible leaks — even those not directly associated with the individual customer’s residence.

Communicating both NRW detection and remediation efforts can go a long way toward improving customer understanding and empathy for water conservation and the true value of water.

Having reliable data collected from newly installed flow- and pressure-sensing technology can also help to justify needed utility repair efforts and document successes.

In addition to having reliable data for better decision-making, using that collected data to document infrastructure leaks and repair efforts for periodic customer communications can improve customer appreciation for the realities of aging infrastructure issues.

That can pay dividends in terms of reduced complaints about street excavations and detours for repairs and pave the way for better justification of rate increases where needed to maintain regulatory compliance and expected levels of customer service.