CLEVELAND, Tenn.-Cleveland Utilities will tackle the worst of its sewer line inflow and infiltration problems with a little outside help this September.
In a 4-0 vote in a Thursday afternoon meeting, the utility board approved a $350,000 agreement with Littlejohn Engineering Services to help Cleveland Utilities address the biggest problem spots of its 204 miles of sanitary sewer line.
"Sewer line rehabilitation is not an option," said Cleveland Utilities General Manager Tom Wheeler.
Inflow and infiltration -- unwanted water flow into the sewer system -- typically come from rainwater entering through broken pipes and damaged manholes, Wheeler said.
The utility manager noted environmental and economic reasons for efficient sewer maintenance: excessive infiltration can result in overflows and the extra water costs just as much to treat as actual sewage.
Littlejohn Engineering will target its approach, said Chattanooga branch manager Scott McDonald in a presentation.
The company will use field inspections, closed-circuit cameras and nontoxic smoke as part of its systematic review of the utility's worst inflow problem areas, McDonald said.
Craig Mullinax, manager of Cleveland Utilities' water division, added that $1.25 million already was set aside for line rehabilitation and manhole repair in the current budget.
Littlejohn Engineering will focus much of its effort in southern Bradley County, in an area roughly defined by Chattanooga Pike, Varnell Road and Blackburn Road, according to McDonald.
The area comprises only about 11 percent of the total system but is responsible for nearly 23 percent of its inflow and infiltration problems, according to a study conducted by Littlejohn.
The oldest portions of the sewer line infrastructure were not necessarily the most vulnerable to infiltration, McDonald said. Poor quality materials from the 1980s and 1990s often resulted in more problems than with clay pipe work completed in the 1940s, he said.
Wheeler said the sewer system experienced nearly 60 overflows after only three-quarters of an inch of rain 35 years ago; today, 3 inches of rain might result in five overflows.
Paul Leach is based in Cleveland. Email him at firstname.lastname@example.org.