A lateral is a section of smaller pipe that transports sewage from a customer’s property to SASD’s main sewer line in a street or a utility easement (see our 3D Sewer Diagram for a good visual). The lateral consists of a customer-owned upper lateral and an SASD-owned lower lateral. The upper lateral is the responsibility of the property owner to maintain, while SASD is responsible for the lower lateral. The length of the lower lateral may vary from a few feet to many feet depending on how your property was developed by the builder. The lower lateral begins at the SASD cleanout and is typically shorter.
When is lower lateral cleaning necessary?
SASD owns and maintains 1,500 miles of lower lateral pipes. Not all lower laterals require cleaning, but some lower laterals have conditions that require ongoing maintenance activity—usually cleaning—at specific frequencies to ensure the flow from the customer’s home or business is not obstructed. This is important because blockages could cause a sewer overflow or even a messy backup into the structure.
How is lower lateral cleaning done?
The crews that do this type of cleaning use special “Minuteman” trucks equipped with various types of high pressure jetting nozzles. If roots or debris are found to be causing any kind of obstruction, the crews will clean the lower lateral using special “hydrovac” trucks equipped with a large water tank, a water pump, and a hydraulic hose for pressurized spraying.
Lower laterals can also be cleaned with rodding machines. These machines use a cable with a cutter attachment on the end to cut the roots and knock the debris loose. The debris then gets pushed into the main line, where the flow pushes it through the system to larger pipes and, eventually, to the treatment plant.
After cleaning, a Television Inspection (TVI) is done to ensure the lower lateral is free of debris.
What are the impacts to customers?
Most lower laterals are in front yards, which usually make the impacts minimal. Sometimes, however, lower laterals are located in backyards. If rodding is necessary, our crews have to get the rodding machine—which is about the size of a lawn mower but much heavier—into customers’ backyards. In those cases, our crews use mats to protect the lawn.