Sustainability is one of the most important issues facing municipalities today. City and state governments are investigating and implementing various energy-saving measures to improve aging infrastructure and draw closer to energy independence. From renewable energy technology like solar photovoltaic systems to lighting and cooling retrofits, myriad options exist for utility managers to reduce overall energy usage, be better stewards of taxpayer dollars, and lower their carbon footprint.
The City of Kingsport, located in the northeast corner of Tennessee, is taking an innovative approach to building a more sustainable community by improving its water distribution system. The city has long been a pioneer in innovation; it was one of the first municipalities to adopt the city manager form of government, and was the 2009 recipient of the prestigious Innovations in American Government Award from Harvard University.
Building on this legacy, Kingsport became Tennessee?s first city to upgrade its municipal water infrastructure with automated meter reading (AMR) and leak detection systems using performance contracting as its procurement strategy. In the fall of 2008, city leadership turned to Johnson Controls to implement the system-wide utility improvements that would save Kingsport valuable water resources and reduce operational costs.
Comprehensive Water Solutions Identify Leaks
As the City considered the upgrades, it estimated it was losing more than 1.2 million gallons of water per year due to leaks. City leadership turned to Johnson Controls to help identify and manage water loss with targeted solutions that provide a comprehensive water loss management program. The solution also provides Kingsport with the technology to lower operating expenses and save valuable resources, all while practicing fiscal responsibility.
Water loss is grouped into two categories ? real losses and apparent losses. Real losses constitute water that physically escapes the distribution system and does not reach the end user. Apparent losses are essentially accounting errors, where water reaches the customer but the utility is unable to bill for it. This could be due to a number of reasons, including inaccurate meters, inaccurate meter reading as a result of human error, improperly sized and typed meters, billing system errors, and theft of service. These two categories can be mitigated through leak detection and AMR systems.
Leak Detection System
To minimize real water losses, Kingsport implemented a leak detection system designed to identify and prioritize leaks for repair in the least disruptive manner. Electronic sensors were placed on service lines immediately upstream of the water meter. These sensors detect leaks by recording the frequency of vibrations that are transmitted through the service lines. The leak detection sensors are turned on each morning from midnight until 4:30 a.m. The leak detection system is most effective during this timeframe for three reasons. First, municipal water usage is at its minimum level. Second, system pressure is at its highest, and third, the background noise is also at its lowest level of the day.
The leak detection data is then stored internally until city staff retrieves it via a mobile collector. The data is then uploaded to a customized website for analysis. Once the data has been reviewed, the secure website will display a map of the city that is populated with colored balloons that indicate the leak status for a particular sensor. A red balloon indicates a probable leak site, a yellow balloon denotes a possible leak site, and a green balloon indicates that no leak is present. This data is also prioritized according to apparent severity of the leak, and the analysis results can be exported into a spreadsheet.
Equipped with the prioritized list, the leak repair crew can locate the site of the leak or break using a correlator. The results of the correlation are confirmed by listening through a ground microphone. Using a correlator and a ground microphone allows the leak repair crew to excavate only a small area, ensuring that traffic is minimally disrupted, fewer resources are used, and the leak is repaired more quickly.
Since Kingsport installed the new leak detection system, 55 leaks and breaks have been found, enabling repairs that now prevent the loss of nearly 620 gallons of treated water per minute. The system has been online and operational for nearly 18 months, and the amount of water and money that the city has been able to recoup is making a significant impact on the city?s budget.
Automated Meter Reading System
Johnson Controls worked to reduce apparent water losses by replacing inaccurate water meters with new water meters that were also equipped with encoding registers and an AMR system. The mobile AMR system allows city workers to read meters remotely from their vehicles, increasing the accuracy of meter readings and improving customer service. This allows for proactive management of billing issues and helps to keep the distribution system in peak condition.
As part of their project with the city, Johnson Controls provides Business Review Services, which reviews system data on a quarterly basis. A Johnson Controls performance assurance engineer monitors and reports on the status of critical accounts, the accounts that had abnormally high or low billed usage, and the accounts that generated conditional alarms.
Performance Contracting Funds the Program
Implementing a robust water loss management system in a municipality provides efficiency, and offers environmental, operational and maintenance cost savings benefits for a community, but it can be an expensive endeavor. Many cities explore federal funding programs, bonds, grants and other funding mechanisms that can help defer costs. Performance contracting is a unique funding concept that continually has gained traction with municipalities interested in increasing efficiency, improving customer service, conserving both energy and water, and reducing operational and maintenance expenditures. ?
The City of Kingsport chose performance contracting to finance its water infrastructure improvements. This solution provided the city flexibility to utilize existing budgets in the most beneficial ways possible.
Performance contracting allows the city to reduce its utility costs and carbon footprint. Cost savings and improved billables generated through reducing real and apparent water losses will repay the project investment over the term of the contract.
The two systems are expected to reduce the city?s costs and improve overall billables over a 17-year period. These savings are guaranteed through the energy services provider, who will repay the customer for any savings not realized. ?
The city manager and public works director have worked diligently to improve city infrastructure and realize substantial savings. The performance contract supports this vision by enabling infrastructure improvements without using capital dollars, reserve funds, raising taxes, rates or user fees, or issuing revenue bonds.
In the State of Tennessee, performance contracts are procured under the Professional Services law and are awarded on the basis of recognized competency and integrity. Energy savings performance contracts ? entered into with qualified energy services companies (ESCOs) ? include both engineering services and equipment, with the purpose to reduce energy costs in public facilities.
Kingsport ? A Leader in Water Loss Management
Potentially fewer than two dozen cities across the United States currently have in place these types of advanced leak detection and AMR systems. Kingsport is one of an even smaller group that actively uses its water loss management program effectively. The city consistently logs and repairs leaks, prioritizes water infrastructure damage, and analyzes leak data to proactively manage its distribution system.
The State of Tennessee has adopted legislative requirements that require municipalities to conduct annual audits of water infrastructure, usage and losses. Once the state selects a water audit format, utilities may be required to put together action plans outlining the steps each will take to improve water infrastructure. As water becomes scarcer and water rates increase, other states may soon follow suit, making water loss management more vital to the health and prosperity of communities across the country. ?
Improving water infrastructure is a valuable way for municipalities to reduce costs and take the next step toward sustainability. Water and energy are interconnected, underscoring the importance of reducing both to realize greater energy efficiency. It takes large amounts of water to produce energy and conversely, substantial amounts of energy to distribute water. Leak detection and AMR systems are two key options that water utilities now have available to improve distribution systems while saving energy, increasing billable usage, and reducing operational and maintenance costs.
Identifying a comprehensive water loss management program through performance contracting provides municipalities with a responsible way to achieve environmental and community goals. Performance contracting also allows cities the opportunity to apply for federal grants, stimulus funds or low interest loans within the contract structure to realize further savings. Municipalities can customize performance contract offerings to include facility upgrades, renewable energy technologies and educational components.
Kingsport sets an example for other municipalities across the nation on what a successful water loss management system can mean for a community. Innovative financing options can help upgrade aging city infrastructure, reduce real and apparent water loss, lower operational and maintenance costs, and create a more sustainable environment. Through creative planning and a vision, other municipalities can learn what Kingsport has learned ? sustainability can be a reality for any community through water technology. ?
Craig Hannah, P.E., serves on Johnson Controls water technology team. Hannah volunteers on the AWWA Water Loss Control and Customer Metering Practices Committees, and his research has been published in numerous industry publications. He earned a bachelor of science degree in aerospace engineering from Texas A&M University and a master of history degree from Texas Tech University.
