Tag: m36

Identifying Non-Revenue Water — And Why It Matters

In the United States, there are approximately 170,000 public drinking water systems, with 54,000 of them collectively delivering water to more than 264 million people, more than half of the country’s population. Unfortunately, due to the state of our nation’s drinking water system, limited infrastructure funds, and climate change, we are losing approximately seven billion gallons of water a day.

So where exactly is that water going?

Non-Revenue Water Crisis

Non-revenue water (NRW) is water that has been, essentially, dined and dashed, or water that has been consumed but not paid for by way of inaccurate meter reads or theft. Additionally, leaks in the system can be a major contributor to NRW.

With NRW comes two main types of loss: apparent and real loss. Apparent losses occur when water is delivered to the consumer but is either measured or metered incorrectly. Real losses occur when water is physically lost and never makes it to the consumer. While a very small amount of NRW comes from firefighting, hydrant flushing, municipal construction, and street sweeping, this is considered to be an “unbilled metered” source of NRW and is not considered a part of the “real loss” crisis. (You can find more information on different forms of NRW here.)

So, how does this affect the general public? Well, if you use less water, your monthly bill will go down, as with any typical utility. However, if water is being lost within the plumbing in your house, and there is a higher demand, your monthly bill will be raised. In fact, the average household in the US loses approximately 10,000 gallons of water a year, meaning NRW affects, quite literally, everyone.

Hundred-Year-Old Pipes

In the United States, there are an average of 240,000 water main breaks every year, with approximately 650 to 700 happening per day. Unfortunately, this information isn’t entirely shocking given that a large amount of our nation’s pipes and mains are over a hundred years old and in need of critical replacement in order to prevent further breaks. As it turns out, 75% of drinking water investment needs are for repairing and replacing leaky pipes.

Drinking water system component parts have an average life expectancy of fifteen to ninety-five years, so while new pipes are being added to expand our current systems, other parts are continuing to degrade. Degrading leads to water main and pipe leaks, which not only disrupt service to customers, but can also cause the subsurface of our roads and public infrastructures to erode which, when untreated, can eventually lead to road collapses and deteriorating building foundations. Just as concerning, broken or leaking pipes invite the potential for toxins and disease-causing pathogens to enter the water supply, causing water quality issues that require mitigation — yet another expense.

Why Water Audits?

To fix all of our water distribution systems, it would cost the United States approximately $200 billion, and almost half of that money would be allocated for water loss control. With water audits, the most critical areas can be identified first so the (already limited) funds can be dedicated solely to repairing the infrastructure. From there, water audits can help municipalities develop strategies and courses of action for future problem areas; recapture lost water; decrease the need for new sources, treatment plants, facility upgrades and expansions; and reduce the number of entry points to disease-causing pathogens.

Water audits follow the M36 Water Audit methodology from American Water Works Association (AWWA) and are an affordable and efficient solution to increasing water availability and helping to identify the costs and causes of water loss. In the past, Tata & Howard has been retained by the Towns of Wayland and Grafton, MA, and South Central Connecticut Regional Water Authority (SCCRWA) to complete water audits to determine the volume at which NRW is occurring, potential sources of the lost water, and make recommendations on how to reduce future water loss.

For more information on water loss control and the M36 methodology, take a look at our webinar here.

The Real Cost of Non-Revenue Water and How a Water Audit Can Help

Physical losses such as leaking or broken water mains are known as real losses. There are about 240,000 water main breaks per year in the US.
Physical losses such as leaking or broken water mains are known as real losses. There are about 240,000 water main breaks per year in the US.

Every day, United States utilities lose around seven billion gallons of clean, treated drinking water. This “lost” water, referred to as non-revenue water (NRW), is caused by a number of factors, including leaking pipes, water main breaks, theft, and improper accounting of water. In fact, we lose enough water each year to supply our ten largest cities. Of the estimated $200 billion needed over the next 20 years to upgrade our water distribution systems, $97 billion is needed for water loss control. With water crises occurring throughout the country, NRW is a big deal.

How NRW Affects You

Non-revenue water affects everyone in a water distribution system. Although it is considered “non-revenue” water, many utilities include these costs in their rates, which is reflected in your bill. The less NRW a water utility produces, the lower its total costs will be. And let’s face it: no one wants to pay for things they don’t use. Also, a lower percentage of NRW reflects positively on your local water utility’s performance. Utilities with low NRW percentages typically perform well at replacing broken water mains and meters, and defending against theft.

Metering errors, theft, and billing errors result in water "appearing" to be lost. These non-physical losses are called apparent losses.
Metering errors, theft, and billing errors result in water “appearing” to be lost. These non-physical losses are called apparent losses.

When water leaks from pipes, it can erode the subsurface underneath roads and other public
infrastructure. When the erosion reaches a critical point, the road collapses or a building’s foundation can fail. The better your water utility performs in NRW reduction, the less likely your community will need to replace its public infrastructure, especially roads. Our population is continuously growing and without improved efficiency, water supply expansion and treatment projects will be necessary — significantly increasing the cost of water. Improving water use efficiency by reducing NRW defers the expense of water supply expansion and treatment. If we can prevent clean, treated water from getting “lost,” there will be less of a need to find new sources or increase capacity.

Leaking pipes contributing to non-revenue water also can pose a health risk to communities. Contaminated groundwater from leaking sewage or pollution can find its way into drinking water pipes during low pressure events. Contaminated drinking water then has the potential to spread disease and other harmful substances.

Water Audits and NRW

Non-Revenue Water infographic 11x17
Infographic of the high costs of NRW. Click the image to see it full size.

The best way to reduce a utility’s NRW is through routine water audits. Most utilities in the U.S. conduct infrequent water audits and, therefore, are likely suffering substantial losses without even being aware of it. Since 2005, a number of state and regional water resource agencies in the United States have established water audit reporting requirements for water utilities. In addition, the American Water Works Association (AWWA) has developed and published a methodology for identifying and controlling NRW, M36 Water Audits and Loss Control Programs, now in its fourth edition. Tata & Howard Vice President Steve Rupar, P.E. co-authored chapters 4 and 5 of the new M36 manual, which focus on the causes of apparent loss and what can be done to control it. An expert in water loss control, Steve has also given presentations and a webinar on the subject, which can be found here. Water audits help utilities identify the causes and costs associated with water loss, and develop strategies to avoid NRW. They also help to identify areas of a distribution system requiring repairs or maintenance. Water audits are important, especially in the northeast, where some infrastructure is over 100 years old. Preventing NRW helps save our infrastructure, our money, and most importantly, our water.

In Conclusion

NRW affects everyone, and it’s important to monitor and continuously improve water Dripping-Faucet-300x225distribution systems. Water audits are a vital step toward reducing lost water while improving water infrastructure. We lose billions of dollars every year to NRW — money that could be used to improve our infrastructure or to support other clean water initiatives. Water lost is water and money wasted, and the less NRW a utility has, the better off it — and its customers — will be.