McRAE, Ark. – Mayor Robert Sullivan inspects one of the newly-lined manholes of the McRae, Ark. wastewater collection system. Assistance from the Arkansas Rural Water Association and funding from USDA helped refurbish the manholes, solving an inflow problem and saving the community over $3,000 per year.
“We had just completed upgrades on the wastewater plant and had a contractor reline the collection system in-place,” explained Sullivan, who also manages McRae’s water and wastewater operations. “But we still had a lot of infiltration.”
Arkansas Rural Water performed an energy audit of the wastewater system, and found considerable variation in the amount of power the plant consumed. Typically, wastewater power usage is roughly constant and matches the amount of water distributed by the drinking water system. The evaluation revealed that additional water was entering the wastewater system, a process called inflow and infiltration, and McRae was paying to pump and treat this additional water.
“We discovered that roughly 22% of the utility’s annual electric bill went to pumping rain water that had entered through leaks in broken lines and manholes,” said ARWA Executive Director Dennis Sternberg.
ARWA performed a smoke test of the sewer system. A smoke test forces non-toxic artificial smoke through waste pipes under slight pressure. Any sign of smoke escaping is a potential leak and there was a large amount of visible smoke during the McRae test.
“Some of the manholes had leaks as big as your finger in them,” Sullivan said.
After inspecting McRae’s system, ARWA devised a plan to repair and rehabilitate 24 manholes to prevent future inflow and infiltration. Rural Water recommended using a contractor to make repairs and line the manholes with a material that would seal them against leaks. The Rural Water inspection and recommendations provided McRae all the paperwork they needed to quickly seek bids and find a contractor.
“They really took it from the beginning,”Sullivan said. “They got us everything we needed to move quickly.”
Rural Water also worked with the community to fund a fast, easy solution to funding the manhole repairs. McRae had used the USDA loan and grant program to fund construction of their wastewater plant, and they still had money left over from that project.
Contractors repaired the leaks and coated with manholes with a spray-on lining that sealed them from further infiltration. The rehabilitation is expected to save the utility over $3,000 dollars per year in pumping costs, plus additional saves in equipment wear and increased service life.
“The manholes were starting to deteriorate and now they’ll last another 20-30 years,” Sullivan said.
Sullivan credits the success of the project to the assistance of ARWA.
“Rural water has been one of the greatest assets we’ve had access to,” he said. “They have an expert for every field of water and wastewater. They go out of their way to help us with anything.”
“You could not find anyone better,” Sullivan said.