New sewer mains were constructed using tunnelling, microtunnelling and HDD, while aged mains were rehabilitated by sliplining, cured-in-place pipe (CIPP) lining, fold and form lining and casting PVC corrosion resistant liners in place.
The Department of Public Works launched the use of trenchless methods more than 15 years ago and has saved the city more than $US80 million in construction costs.
The sewers ranged from 6–120 inches in diameter and newly constructed mains are up to 150 inches.
City Engineer Gary Lee Moore said driving and traffic in Los Angeles was a major consideration for the sewer upgrade project.
“Our engineers recognised this challenge and found a way to keep people moving while also accomplishing the important work of renewing the sewer system,” he said.
Materials used in the upgrade included vinylester resin CIPP, high density polyethylene slipliner, fold and form, PVC cast in place liner and fibreglass reinforced pipe.
