Patrolling the pipes
Chris Carillo maneuvers a long, skinny hose with a camera on its nose down through a manhole in front of Lanza’s restaurant in Kings Beach.
Carillo, a maintenance worker for the North Tahoe Public Utility District, is checking the sewer line for grease buildup and water infiltration. He and other maintenance workers daily inspect North Tahoe’s sewer system for roots, cracks, debris, sags in the line and grease ” with television cameras that offer them an intimate glimpse of the pipes’ health.
Like the Tahoe City Public Utility District, North Tahoe used to contract out sewer camera inspections, but bought a camera of its own last year.
“We have probably caught things we couldn’t with contractors,” said North Tahoe Public Utility operations manager Rob Hopkins. “It has probably prevented a couple of sewer spills from happening. We can just pick up and go. It just allows us to verify things.”
The camera cost the district $23,000, but has already paid for itself, Hopkins said.
North Tahoe inspects all 88 miles of its sewer system about twice each year, and more often for the pipes subject to problems, Carillo said.
Tahoe City doesn’t have its own camera crew, but has contracted with private crews since 1992 to inspect and clean the district’s 180 miles of pipe line each year or two.
North Tahoe’s sewer system has been in place since the 1960s and has pipes made of asbestos-cement, clay and plastic. The Tahoe City Public Utility District’s sewer system is also more than 40 years old and some older pipes are subject to numerous cracks.
“Our main concern is to try and keep groundwater out of the sewer system,” said Cris Connolly, North Tahoe Public Utility District’s operations crew chief.
Maintaining a tight system helps keep operating costs down. Additionally, too much extra water in the sewer system can cause it to overload, said Tony Laliotis, Tahoe City utility superintendent.
“Slowly but surely we’ve been tightening up our system,” Laliotis said.
The biggest problem that sewer pipes face in this area is root infiltration and grease clogs.
Particularly in restaurant-dense areas like the commercial cores of Kings Beach and Tahoe City, grease solidifies in the pipe lines as it cools, and blocks the passageway “just like your arteries,” said Cindy Gustafson, the Tahoe City assistant general manager.
To combat major grease buildup, the North Tahoe utility district inspects restaurants to ensure they have proper grease traps in place. Connolly said the rules on grease interceptors are getting stricter.
“There’s been grease buildup as big if not bigger than softballs,” Connolly said.
Aspen trees pose another problem because their roots, in search of water and nutrients, find their way into the pipeline.
“Whenever you have roots coming in, you know you have water coming in,” Connolly said.
When sewer cameras do find problems in the pipes, the districts fix the most pressing issues first. Cracks are sealed with a chemical grout. If grease and roots are the problem, the districts bring in a supercharged hydrocleaning device and vacuum to clear the passageway.
The high-pressure machine shoots out 80 gallons per minute of water at 2,500 pounds per square inch to break the grease buildup free or slice away the tree roots.
“It would cut your hand,” Laliotis said of the stream of water.
Then a special vacuum sucks up the debris so that it doesn’t travel deeper into the system and cause repeated blockages.
But when pipelines finally need replacing, it can be much more costly than cleaning. According to the North Tahoe Public Utility District, the cost of replacing a line runs up to $1.5 million per mile of pipe.
Because the cost of construction increases about 15 percent each year, replacing the lines becomes more pricey with each passing year, Hopkins said.
But the North Tahoe Public Utility District aims to replace an average of 1,100 feet of sewer lines each year.
– Kara Fox contributed to this report
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