4 minute read
Water Loss and the Aging Infrastructure
By TRWA Circuit Ride James Smith
In one of my first jobs as an operator, I remember being told that the water system’s water loss of 11 percent for the month and 15 percent for the year was acceptable. Thirty-five years later, these standards are still cited as acceptable average water loss for a system. That same water system I worked for all those years ago still has some of the old original pipes in the ground, which hinders their ability to stay under that 11 percent monthly goal. Water loss may also occur due to loss of pressure in the distribution system for various other reasons, including water main breaks, equipment failures, and loss of power.
To understand how a system is losing pressure, water systems need to figure out where their water loss is going. There are typically two categories of water loss: apparent loss consists of accounting errors, inaccurate meters, and illegal connections; real loss consists of leaks on water lines, storage tank overflows, and flushing of dead-end mains.
To determine which of these categories is affecting pressure, systems need to look at customer use and patterns. Residential meters may need to be replaced when they roll over or when they reach nine to 10 years old, depending on the area and the system’s water chemistry. Meter replacement programs can be implemented by reviewing each meter on the system and replacing the oldest first and so on. If a system can’t afford to replace all the meters at once, I advise setting up a change out program. At the system I mentioned before, the team looked at the cost and saw that we could afford changing out 10 meters a month, so we started doing so.
There may be some setbacks when implementing system-wide change outs. Once a system starts the program, especially if done incrementally, it may take time to see water loss volumes decrease. Additionally, after replacement with the new meters, some customers may call about a higher water bill. The system may need to explain that the water consumed may not have increased, but that the new meter is accurately accounting for the water used. Doing a consumer-education campaign in the area before meters are replaced may help to abate some of the confusion.
Another issue causing water loss is deferred maintenance. In too many water systems, the infrastructure is overworked and/or maintenance is under-budgeted. The systems are stressed, and the finances and resources are limited. In order to save the water system in the long-term, system stakeholders have a responsibility to continue working and replacing old and outdated water lines, and other key components of the system. There are multiple grants and loans offered for rural systems to work on their infrastructure. TRWA is a resource to learn about how to apply for those funds. Neglecting a system’s lines is only of benefit in the shortterm; the water loss will continue and likely worsen.
Leak detection and line repair are tough. Sometimes, multiple operators and managers just cannot find the leak (unless you’re Charlie, the leak detection dog who stars in this issue). Despite the difficulty, every system should still be aggressively involved in leak detection and line repairs, and if the line is bad enough, line replacement. To help those of us without super-hearing, sometimes an operator can close valves and isolate an area of the system during nighttime hours. Once the operator waits a few minutes or longer, they can slowly open the valve and listen for water rushing or filling the downstream side of the pipe. There are several other techniques and tricks to help a team detect leaks as they perform routine checkups.
Water systems should also practice mapping. The system map should be large enough to show the entire system, so that all staff and board members can refer to it at any time. The map should additionally show all water lines, valves, storage tanks, and water meters. This map should also have historical data on it such as colored top pins to mark all meters and, importantly, all the leaks that have occurred from day one updated each time a new leak is found. This helps the decision-makers in a system by providing a visualization of the system’s leaks. This visual can spur discussion of line replacement if the leaks in an area are obviously chronic or unfixable.
Obviously, water systems must get the most out of the life expectancy of new water lines and make sure they are installed and bedded and also pressure tested properly. The additional practices of meter replacement, robust, ongoing maintenance, and a visual mapping program help prevent water loss on a large scale. If your system is not currently implementing these programs, there’s no time like the present to begin.
If you are interested in any of the member benefits discussed in this article, contact us at 512-472-8591 or email membership@trwa.org.
