Town will buy equipment for needed inspections
By Ann McCreary
A video camera mounted on wheels was lowered into a manhole in Twisp recently and took a trip through a town sewer pipe.
The camera transmitted images to a screen above ground, where an operator used a joystick to guide the camera on its wheeled carrier through the sewer.
During its journey, the device discovered a large root wad that had broken through the walls of the sewer line, which is exactly what the equipment is intended to do — find potential problems before they cause real trouble.
The sewer tour was a demonstration of closed circuit television (CCTV) inspection equipment that Twisp’s Public Works department plans to purchase in order to conduct a complete inspection of the town’s sewer system — for the first time.
“Our system has never been inspected,” said Andrew Denham, Twisp Public Works director. “The system was installed in 1975. Those concrete sewers have a 50-year life span so we’re nearing the end of that life span,” Denham said.
“We’re being proactive,” he said. The town recently experienced a backup in a sewer line that goes under the Methow River, he said. “It would be very serious if it backed up and overtopped the manhole and went into the river.”
Fortunately, that didn’t happen. That kind of mishap would bring the attention of state and federal environmental agencies and probably result in a fine, he said.
Denham said the town will purchase the inspection equipment, which costs $35,000–$70,000, as part of a state grant that will fund a general sewer plan and biosolids management plan for Twisp.
The CCTV camera can pan, tilt and zoom to examine the condition of the sewers, find obstructions such as roots and grease, and locate lateral connections. It can travel up to 600 feet. Most manhole covers are about 300 feet apart, according to Twisp public works officials.
“We’re going to end up owning a very high-tech remote control camera that we’ll be able to use for investigative work for year to come,” Denham said. “To have an outside agency come in and do that work would be far more expensive than buying the materials.”
After a complete inspection of the sewer system is conducted, Denham said he’ll be able to develop a capital facilities plan with a prioritized list of maintenance and repairs that will address the long-term needs of the system.
“A water system plan was completed about two years ago,” Denham said. After the sewer plan is completed, “Twisp can have an integrated plan.”