Sewer Laterals

Sewer laterals are connections in sewer pipeline construction that are common whenever installing new pipe or improving current sewer pipeline systems for both public and private construction projects. Sewer lateral connections are the actual material and methods used to join a sewer line coming from a private property (sewer lateral) to the public sewer main line. Three most common sewer lateral connections are wye connection, saddle connection, and cut-in-wye connection.

The most common type of sewer lateral connections to sewer main pipelines are wye connections. Wye sewer lateral connections are manufactured in the shape of the alphabet letter "y". This type of connection is installed whenever there is a new sewer pipeline installation requiring new sewer laterals to individual properties. Unlike pressurized water pipeline systems, sewer and storm drainage systems are designed using gravity flow wherever possible. The "y" shape is more favorable to the gravitational flow pattern of sewer systems by directing flow of sewage into the same direction as the flow in the public sewer main line. Therefore, sewer main lines are less likely to have any clogs or backup. ye connections are made by attaching wye material to the ends of sewer main line pipe as the main line is being installed. Wye connections are installed at designed and required locations for the new laterals. Sewer wye connections are available in various types of material including polyvinyl chloride (PVC) and vitrified clay pipe (VCP) material, but typically, these sewer lateral wye materials are made of the same material as the sewer main line (i.e. a VCP sewer main will have a VCP material wye sewer lateral connection as well).

Sewer saddles are another type of lateral connection. This type of connection is used when public sewer lines are existing, and a property owner requires a new sewer lateral connection be made to the existing sewer pipeline main. As the name implies, it is saddle-like in that it connects to the outside of a sewer main pipeline. The saddle connection is made by first coring a hole into the sewer main line pipe. Then, a pipe layer connects the saddle over the hole and secures the saddle to the outside of the main in various ways depending on type of pipe being installed. Like sewer wye connections noted above, sewer saddle connections are also available in PVC and VCP material, usually matching the same material as the sewer pipeline main.

Cut-in-wye connections are also used when public sewer mains are existing, and a property owner requires a new lateral connection be made to the existing sewer main line pipe, but the public sewer Agency does not want or allow the saddle connection. Instead, the Agency may require a wye connection installed in the already existing sewer pipeline main. This requires the sewer contractor to literally cut out a section of existing sewer pipeline main and install a wye connection with repair couplings typically of the same size and material as the sewer pipeline main. This type of connection often requires existing sewer flows to be rerouted around the area of work with pumps and hoses, also known as sewer bypass.

Types of public sewer materials used for sewer lateral connection are determined by public agencies who own the sewer pipeline mains. Materials for private sewer lines are determined by plumbing codes and the owner's choice of materials from these codes to install a sewer lateral. In any case, material verification and inspection by public agency are generally required whenever connecting a new sewer lateral to a City or Agency-owned sewer main. Lastly, since connection methods vary as described above, be sure to know which method is acceptable to ensure the correct installation of a new sewer lateral connection.

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Published on February 27, 2011 | Comments: 0

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