CITY FIXES SEWER LINES WITH TV, FELT

Television cameras, felt and several gallons of water are the essential tools used to repair broken sewer pipes in Cape Girardeau.

The Public Works Department is using a process called Insituform to repair more than 950 feet of damaged sewer lines. Crews are expected to finish the project by Monday.

Using the new process prevents digging up streets and rerouting traffic, said Steve Cook, environmental services coordinator for the department.

Repairs are being made to 8- and 10-inch sewer lines at Lyndhurst and Huntington drives, Thomas Drive and West Mount Drive. Repairs on North Kingshighway have been completed.

Most broken lines run through yards, under streets and creek beds, as well as behind storage buildings. Some of the lines have as many as six breaks per line, Cook said.

The three-step Insituform process uses television cameras to find the breaks and clear out the lines. The second step uses a white, felt tube that resembles an inside-out sock. The tube is forced into the manhole with water and turned inside out so the smooth side becomes the interior.

In the final step, the water is heated to 180 degrees and thermosetting resin is cured to create a 3/8-inch liner in the pipe.

"We invert the liner to create the new pipe," said Greg Grapenthin, a crew member. "When the work starts the water is at ground temperature. We usually work as long as temperatures are above freezing and we have access to water."

Cold weather doesn't really affect the process, but it does slow it down, said crew superintendent Bill Bull.

The repair process will cost the city about $76,000 but Cook said it was the most cost effective method. The alternative would have been to tear up the streets and go underground to repair the sewer lines.

"A resident doesn't notice any change," Cook said. "They may notice a truck sitting around and a tripod apparatus with a white tube in the manhole versus seeing the street all torn up."

The repairs will be finished in one day using Insituform, but using any other method the work could last several days, Bull said.