Sewer rehab nears completion

Fayetteville Public Utilities has made great strides with system improvement in two major areas: less groundwater infiltration of FPU’s underground sewer lines and significantly lower inflow at FPU’s Wastewater Treatment Plant. Those two improvements alone result in less water being treated at the plant thus creating an operational-cost savings to FPU and to our customers.

FPU and its contractors, CFW, Inc. from Fayetteville, TN, and LTS Construction from Winchester, TN, have been working along city streets and avenues to continue upgrades of our sewer system as part of the Tanyard Branch and Laten Bottom basins improvements. Because of previous conditions of these two areas and other problem areas of our wastewater system, FPU was placed under a moratorium preventing new sewer service connections inside city limits.

“FPU has addressed the needed improvements included in the moratorium at its sewer lift stations, corrected overflow issues and is now continuing to upgrade sewer lines,” says FPU’s CEO and General Manager Britt Dye. “With moratorium constraints lifted as a result of system improvements, FPU is able to expand sewer services while continuing to upgrade the system.”

Crews have performed three methods of testing our sewer lines to pinpoint problem areas. FPU first inspected underground sewer lines by installing flow meters which measure the amount of water flowing through FPU sewer lines. These measurements were recorded during normal- and rainy-weather conditions to determine how much infiltration from groundwater the sewer lines were allowing to penetrate the system. FPU next performed smoke tests in search of leaks in the underground sewer system. And finally, FPU used enhanced, video-camera technology to show visual details of sewer line cracks, leaks and infiltration.

“Since sewer lines are underground, it’s more difficult to locate exact areas that need attention without conducting these types of inspections,” says FPU’s Grayson Ray, FPU’s assistant gas/water/wastewater operations superintendent. “These types of tests are done with little, if any, disturbance to yards, roads and driveways and reveal to us how we can better engineer line replacement and repairs.”

FPU estimates that it will repair or replace tens of thousands of feet of sewer lines with the planned system upgrades.

“Some of the old, clay sewer lines have been in the ground since the 1940s and 1950s,” says Ray. “They are perhaps the first, original sewer lines installed in our city and have been in operation ever since. The upgrades we are doing now will be successful improvements for FPU and our customers.”

Recently FPU used the noninvasive, pipe-bursting method to replace sewer lines with more durable and long-lasting polyethylene pipes. The procedure saves time, construction costs and has a minimal effect on customers’ yards, driveways and city streets. With the new sewer lines in place, the old clay and concrete sewer lines were burst into pieces and left underground. Rather than digging large trenches to expose a section of line, the procedure used by FPU only required portions of underground pipe to be exposed at service connections.

During the sewer rehab, some customer sewer lines were replaced to further improve system operation and correct infiltration issues.

The rehab work in the Tanyard Branch area is expected to be complete in May. The next phase of sewer line rehab is slated for the Winchester Highway area.