Trenchless Technology Center
Louisiana Tech University

Water Environment Research Foundation

About This Web Portal

This web portal has been established to provide sewer agencies and property owners the most current information on sewer lateral condition assessment and inspection techniques, repair and rehabilitation methods, legal and financial issues, and a forum for resolving related issues.

Millions of sewer laterals exist throughout the U.S. and many of them are defective. Sewer laterals are designed to convey sanitary wastewater only (i.e., domestic sewage), however, defective laterals typically allow the entry of extraneous water, inflow and infiltration (I/I), into sewer systems. It is important to understand that while defective laterals in one neighborhood may generate only a moderate amount of I/I, this amount becomes an integral component of the total I/I in the sewer system and may significantly contribute to sanitary sewer overflows, increase the cost of wastewater conveying and treatment, or cause costly damage to private property through sewer backups (see “Why is Infiltration and Inflow (I/I) an issue?” in I/I Issue web page).

The defects that are responsible for most problems associated with laterals are usually related to the aging condition of these pipes and include the presence of cracks, missing or deteriorated joint materials, root infiltration from boulevard trees, settlements due to poorly compacted or nonexistent bedding materials (initial construction practice deficiency), separated joints, damage from installation of other utilities in right of way (since original lateral date of installation), etc.

In addition to explaining the main reasons and options for lateral condition assessment and lateral rehabilitation, the web portal also aims at explaining legal and financial issues, as well as bringing attention to other important issue related to sewer laterals such as cross-bores (intersections of one underground utility or structure by a second utility, which present an extremely serious problem because they can cause the damage to private property, the loss of property, and the loss of lives – see Cross-Bores).

About Terminology

In the web portal, terms “lateral” and “sewer lateral” are used interchangeably to denote pipes that connect individual properties (residential houses) and public sewer network (sewer mainlines in the street or sewer easement pipes). The term “private sewer lateral” denotes privately owned portion of sewer laterals, which, depending on the sewer agency, may extend (a) from the house to the property line, (b) from the house to the mainline excluding the connection to the mainline, or (c) from the house to the mainline including the connection to the mainline (see FAQ in Discussion Forum , as well as "Private Sewer Lateral – Definition and Why It Is Important" in Legal/Financial Issues ). Basic terminology related to sewer laterals is shown in figure below:

     Sewer lateral showing basic terminology


The primary source of information for this web site is the publication:
     WERF, 2006. Methods for Cost-Effective Rehabilitation of Private Lateral Sewers, WERF 02-CTS-5, Alexandria, VA, 436p.

However, the information presented at this web site is not limited to the state-of-knowledge presented in that report; this information is being continuously updated to reflect the ongoing changes in the applicable trenchless methods and products for lateral inspection and repair offered on the U.S. market. Other relevant references are shown on those web pages where they were useful for preparing the displayed contents.



Copy Right: TTC Louisiana Tech University
Ruston, LA