The city of Los Angeles, CA, recently completed 1 million feet of sewer that has been constructed or rehabilitated using trenchless technologies.
The city has an aggressive sewer rehabilitation program to manage and renew its 6,700-mile wastewater sewer system. Always pursuing new, better technologies to protect the city’s aging infrastructure as a valuable resource, the city has embraced trenchless sewer construction methods.
“Angelenos spend a lot of time driving, and traffic in this city is legendary,” said City Engineer Gary Lee Moore. “Our engineers recognized this challenge and found a way to keep people moving while also accomplishing the important work of renewing the sewer system.
“Renewing our world-class wastewater system is essential to the Bureau of Sanitation’s mission of protecting public health and the environment,” said Bureau of Sanitation Director Enrique C. Zaldivar. “Trenchless construction methods offer a win-win because we are able to get the work done with fewer impacts to our partners in the community.”
The city has carried out its mandate to protect the health and safety of its residents while also avoiding more than a million feet of trench, thereby reducing traffic impacts and inconvenience to adjacent homes and businesses. Also, trenchless methods of sewer repair are often less expensive than traditional sewer replacement. Since the launch of trenchless methods more than 15 years ago, the city has saved more than $80 million in construction costs. Traditional open-cut sewer rehabilitation costs approximately $125 per linear foot, and trenchless methods average about $30 per linear foot. Especially in these difficult budget times, that savings is vital to the program’s success.
Because the city is at the forefront of this trenchless trend, other agencies nationwide and abroad have sought information about the results Los Angeles is seeing. The city has implemented leading edge methods and has worked with manufacturers to develop techniques to rehabilitate large, non-circular sewers, live and in place.
The city has been creative in developing and copyrighting a proprietary software package, SMARTS (Sewer Management Automated Repair Tracking System) program. SMARTS is used to prepare plans for the Secondary Sewer Renewal Program that rehabilitates an average of 60 miles of 8- to 16-inch pipe each year. This program produces a reduced format design and bidding package, usually with no drawings, that significantly reduces the cost and time of preparing plans and specifications. This program employs state-of-the-art GIS technology, electronic vault plan retrieval, and sewer video to bring all of the necessary information for the design of sewer rehabilitation projects to the engineer’s desktop.