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By Michael Kanellos

Leakage stands as one of the primary challenges and primary opportunities for water utilities. Globally, the World Bank Estimates that we collectively lose 32.6 trillion liters a year, or nearly enough to fill China’s Three Gorges Dam, through leaks. In some cities, leakage can consume 35 to 50% of the water produced. Lost water, of course, means more than wasting a valuable commodity. Because power can be 30% of the cost of producing water, leakage can artificially raise greenhouse gas emissions and prevent communities from reaching their sustainability goals.

Similarly, leaks in wastewater networks, meanwhile, can be a source of health problems and legal violations.

On the other hand, the volume of water being lost – combined with advances in software and sensors for detecting and monitoring leaks – has effectively made leakage one of the most, if not most, economical source of water available to a community. In the U.S., for example, recovering water from leaks costs on average USD 1.21 per 1,000 gallons, according to data from Bluefield Research, or less than half the cost of traditional water (USD 3.90 per 1,000) and far less than newer solutions like desalination, which averages over USD 8.00. Leakage control is even less expensive than encouraging consumers to conserve, according to data from the California Public Utilities Commission.

Maynilad, the privatized water authority for Manila, serves millions of customers over 540 square kilometers: it manages nearly 7,500 kilometers of water and sewer pipes and 19 reservoirs.In 2007, nearly 20% of the citizens in its service territory could not even get service, roughly had did not have 24-hour service and over half did not have sufficient pressure.

As part of an operational overhaul, the company pursued an aggressive program to monitor metrics like water flows while mapping consumption against its geographies.By 2013, it was servicing 94.7% percent of its customers, 97% had a 24-hour service and 99% had sufficient pressure. At the same time, Maynilad recovered 640 million liters of treated water, thereby reducing losses by 27%, while increasing its customer base from 6.4 million to 9 million.

But what about small cities with relatively modest budgets and small staffs? White House Utility District (WHUD), Tennessee’s largest geographic water utility serving approximately 90,000 consumers and businesses, is using data to stem water loss and create savings for its customers. Detailed in a newly published paper, the District’s work began in 2015 with a dilemma: how to meet growing demand for water within the budget and capital constraints faced by municipal and mid-sized utilities everywhere?

Early projections indicated that WHUD might need to invest up to USD 15 million to USD 20 million in transmission upgrades and treatment plant expansions to meet its service commitments.Expanded capacity would also mean higher expenses in terms of energy -approximately 30% of the cost of producing water – employees, chemicals, and maintenance.

Rather than launch an expensive construction project, WHUD opted to develop a system to pinpoint underground leaks through software and smart meters. First, WHUD segmented its service territory into 33 district metered areas (DMAs). Data from this network of meters was then delivered to OSIsoft’s PI System, a software platform that collects, cleans, and structures data from different devices to give engineers and technicians real-time insight into their overall operations and asset health.

To understand consumption patterns, WHUD monitored water consumption rates between 1:00 a.m. and 4:00 a.m., when few consumers would be awake and legitimate consumption would be at the lowest level within a DMA. If a DMA exceeded a threshold value of 0.5 gallons per minute per household during this time period, PI System data would be employed to narrow down the location of a potential leak. The data would then be placed on an ESRI ArcGIS map so maintenance crews could prioritize repairs.

The Results

In 2015, the first year of the program, WHUD found and sealed leaks losing USD 400,000 worth of water. In the second year, it found another USD 500,000 worth of leaks, resulting in USD 900,000 of saving in 2016 and the cumulative savings to USD 1.3 million, thereby paying off the budget of the project. (Remediated leaks become a recurring revenue stream: The USD 400,000 worth of water recovered by fixing the 2015 was repeated in 2016 and every year thereafter.)

In 2017, WHUD found USD 350,000 more leaks, raising the total water recovered or not lost in that year to USD 1.65 million and the cumulative total to nearly USD 3 million.

  • WHUD had an infrastructure leakage index (ILI) of 2.86 in 2012, which meant it was losing approximately 32% of its water through water main leaks.
  • In less than four days, WHUD discovered what local residents believed was a stream was, in fact, a water main leak spilling approximately 147 million gallons a year, or enough for 2,239 homes in the area.
  • WHUD later discovered another “stream” created by a leak that had spilled 500 million to 1 billion gallons since the late 1980s.
  • The ‘smart meter’ approach also allowed WHUD to avoid USD 200,000 worth of SCADA upgrades and recover USD 30,000 in employee time and productivity.
  • The time needed to prepare reports on potential problems dropped from six hours to ten minutes.
  • Perhaps most importantly, WHUD avoided the multi-million capital expansion. WHUD estimates that the interest payments on the bond payments alone would have come to USD 600,000 per year. WHUD predicts it will not need a major capital expansion until 2028.

“Without us knowing there was a problem in that area, we would have never been able to stumble upon that leak,” said Carl Alexander, GIS Director at WHUD. “Since implementation, this has held true with potential leaks being found daily, some so small they could have gone undetected for years. We have also been able to proactively notify customers that they may have a leak, so it has really been win-win.”

White House Utility District has demonstrated what can be accomplished through digital technology. Just as important, WHUD has shown that analytics and Big Data aren’t just for large utilities with extensive engineering departments.

And, while water utilities are often very conservative organizations, results like this show that the industry could become one of the most important test beds for analytics.

About the Author
Michael Kanellos is the Industry Champion, Water, for OSIsoft.

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