The private sewer lateral is the part of the sewer that runs from the house to the public sewer main, which is located under the street, alley, or in an easement behind the house.
The maintenance and repair of the private sewer lateral is the responsibility of the property owner. But many owners give little thought to this system until a sewage back up occurs, usually due to a damaged or root-clogged pipe, or an offset joint. Repairing damages caused by a sewage backup can cost thousands of dollars; an expense seldom covered by homeowner's insurance policies. Local water utilities in our area offer insurance coverage that can be added to your water bill as a hedge against expensive lateral sewer repairs.
A professional home inspection will cover the interior and exterior of the major mechanical and structural systems of a house such as the HVAC system, Hot water tank, roofing and exterior cladding, soffits, gutter systems, electrical system, built-in appliances, doors, windows, fireplaces and flues, crawl space and attic ventilation and the plumbing system but will rarely include an inspection of the building's sewer (known as the private sewer lateral or side sewer).
For a few hundred dollars, a licensed plumber can visually inspect the private sewer lateral using a video recording system that will show if there are any cracks or breaks in the pipe or offsets, and whether there are any root intrusions from nearby trees, hardened grease, or egg shells, the most common causes of lateral sewer blockage. Repair costs can be several hundred dollars and replacement costs can run into the thousands.
If a private sewer lateral problem is discovered as part of the home inspection prior to closing, the buyer has an opportunity to negotiate with the seller to cover the cost of cleaning or repairs.
Additionally, with a private sewer lateral inspection you'll also learn if the lateral has a cleanout and if that cleanout is fitted with an Overflow Protection Device.
If there is no cleanout, one should be installed. This will provide easy access to your private sewer lateral for cleaning and maintenance. Installing an Over Flow Protection device is an inexpensive way to prevent sewage from backing up into your home. The device allows sewage back-ups to spill outside rather than from a drain inside your house.
Installation of the Over Flow Protection device (which is available at many plumbing supply stores) is relatively simple, but must be done according to your local sanitary district specifications. It's recommended that a licensed plumber install the device since elevation and location are critical for the device to function properly.
Source: The Central Contra Costa Sanitary District PIPELINE, Fall 2009