As Tennessees Oldest Town, Jonesborough boasts a lot of history. But an old town also means an old infrastructure, and in Jonesboroughs case, an aging water system is leaking not just water, but money, too.
The water fund is one place where evidence of leaks in the water system first showed up.
Its Town Recorder Abbey Millers job to compare information on how much water is pumped into the system from the treatment plant and how much usage the town bills. In an ideal situation, that difference should be minimal and explainable.
The difference in there, we should be able to account for, Miller said. Thats what were struggling with.
Water loss can happen in a lot of different ways, and the ability to determine just how much water a system is losing is a long process in itself, especially to get the most accurate amount, officials said.
We have to look at what volume our customer base is using, what the fire departments use, including to flush hydrants, and we have to calculate the volumes to be accurate in finding out what youre producing in the treatment plant and what gets accounted for, said Town Administrator Bob Browning.
The town is also concerned about the large amount of water loss, as well the financial impact that could have.
Were already having to pay to process the water, Miller said. If its finished water were losing, its already gone through the treatment plant and then its getting lost out there.
One cause could be old meters in the system, however, Miller said one meter employee said the amount of water unaccounted for is too large to be a meters fault.
Water loss through old meters can cause an 8 percent loss just in accounting when meters dont calibrate usage accurately, Browning said.
That impacts the system financially, when youre not billing for what is actually used, he said.
Undetected water leaks also cause losses of both water and town money.
Materials in Jonesboroughs system range from certain types of PVC pipe, cast iron, ductile iron pipe and galvanized pipe. Each pipe handles water pressure differently, and that can cause problems when fixing leaks.
Most recently, the town has stuck to using ductile iron pipe, which handles much higher pressures. But a large amount of the PVC pipe remains in the system, and can burst if exposed to such water pressure as the iron pipes can handle. Pressure-reducing valves can often help, through, Browning said
Sometimes, because of pressure differences in the varying materials used to build the pipes, fixing one leak causes another one somewhere else the water line.
We have fixed a lot of leaks, but the problem is, were just moving them around, Browning said.
The town has brought in engineers to work on designing a hydraulically zoned system, a move that could help control the pressure more accurately and allow leaks to be pinpointed and fixed.
A lot of the system problems stemmed from the installation of the reservoir at Persimmon Ridge in 2006, which increased the height and pressure of the towns system, Browning said.
Positives occurred from that update the ability to take on the Lowes project, for example.
However, the change also increased the pressure, and we knew we would have line breaks, Browning said. We found 150 leaks a month when we shifted over.
The town has already repaired enough leaks to reduce the capacity at which the water treatment plant must operate to keep water going to customers.
After repairing leaks, the plant operates at about 80 percent, down from full capacity, Browning said.
The leaks dont show up on the surface and are mostly underground, requiring leak detectors to narrow down the area.
But thats a lot of ground to cover and many different types of pipes to check out.
The Jonesborough system stretches from Fall Branch, to Unicoi and Greene counties, and all the way to the Johnson City limits.
Were spread out, Browning said. We inherited the old Limestone system and made a lot of fixes and improvements. Some of the pipe quality was different, and some of it held up a whole lot better.
Officials are conducing a comprehensive study on the system, and Browning called it a high priority project.
Its a big deal, he said. It has financial implications for us long range. Right now, the plant operates at 80 percent, but it could be 60 or 70 percent. Theres also implications if you have to turn around and do an expansion before you should have to.