CITY OF LOS ANGELES
DEPARTMENT OF PUBLIC WORKS

LATERAL ROOT NOTIFICATION PROGRAM

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It is important that property owners inspect, maintain, repair and/or replace private lateral sewer pipes to help reduce sewer overflows and protect their lateral from further damage.

City Sewers

Tree Root Notification Program

The City of Los Angeles operates and maintains the largest wastewater collection system in the United States. This includes more than 6,600 miles of public sewers serving a residential population of about four million people in a 550- square mile service area. There are also some 11,000 miles of private sewer lateral pipes or laterals throughout the City. Laterals are sewer pipes that extend from building structures to street sewers.

Laterals are sewer pipes that extend from building structures to street sewers. It is the responsibility of property owners to operate and maintain their private lateral sewer pipes.

 ILLUSTRATION OF SEWER LINE LATERALS

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CLOSE ILLUSTRATION

Photo shows tree roots that have grown into a sanitary sewer line and clogged and broke the pipe

Tree roots in sewer pipes cause damage and are the reason why many sewers backup. Roots can enter sewer pipes through cracks or loose joints. Over half of tree roots in the City’s sewer system enter through defective private lateral sewer pipes.

The City maintains its sewers by: (1) routinely removing roots using a chemical treatment process; (2) systematically inspecting street sewers using Closed Circuit Television technology to identify structural defects; and (3) planning and implementing capital improvement projects to repair, rehabilitate or replace structurally deficient sewers.

What Causes Roots to Grow in Pipes?

Roots are attracted to water vapor that escapes through cracks or loose joints in sewer pipes. This means roots will move towards and penetrate through cracks, loose joints or any openings in sewer pipes. This happens even in the winter when trees appear to be dormant.

Once inside, roots will continue to grow and fill the pipe to create a root mass that can become matted with grease, paper and other solid matter. This is what eventually causes a clogged sewer.

As roots continue to grow within a pipe, they begin to expand and exert pressure at their point of entry. This can result in a pipe rupture. A ruptured sewer pipe can be costly to fix or replace.

Signs that a sewer is blocked include slow flowing drains, gurgling sounds from a toilet bowl and wet areas around washing machine floor drains. A pipe that is not cleared will become completely blocked and may rupture.

Pipes Susceptible to Root Damage

Certain pipe material is more resistant to root intrusion than others. Vitrified clay pipes, for example, are more susceptible to root penetration and damage when compared with Schedule 40 ABS and PVC DWV pipes that have fewer and more tightly fitted joints.

What Can Be Done to Combat the Tree Root Problem?

The most common method to remove roots from sewer pipes is to use augers and saws augmented with commercial herbicides that kill roots. Do not, however, use copper sulfate and sodium hydroxide because although these chemicals kill roots, they do not prevent regrowth. They also damage the environment when they flow into our oceans.

A more up-to-date method used to clear pipes is to pump a mixture of water, an herbicide and foaming agent, through the pipe.

Do consult a plumber or sewer contractor before deciding which remedy to use. Consult the Yellow Pages under the heading “Sewer” or “Plumbing” for information on companies that perform CCTV pipe inspection and root control. It is always a good idea to get two or three quotes for any work that must be considered. Hire a licensed plumber or contractor.

For further information:

City of Los Angeles
Department of Public Works
Bureau of Sanitation
Wastewater Engineering Service Division
Lateral Root Notification Program
2714 Media Center Drive
Los Angeles, CA 90065
(323) 342-1566
Email:sewer.root@lacity.org

Other useful contact information:
Sewer Customer Service: (323) 342-6006