Sewer Backup Prevention
Although the County has a rigorous maintenance program for cleaning and repairing sanitary sewer mains, obstructions still occur for a variety of reasons. It is important that property owners ensure that their structures are protected from sewer backups, as they can be expensive to remediate and have adverse public health implications. The DPU wants to actively work with its customers to determine their risks associated with sewer backups and any mitigating measures that could be taken.
Do I Need a Backwater Valve?
The national plumbing code requires that structures with plumbing fixtures located below the elevation of the next upstream sewer manhole be equipped with backwater valves to prevent sewer backups into structures. In 2011, a DPU mapping study of Los Alamos and White Rock identified 2,438 properties that appear to meet this condition. These customers were sent letters notifying them of this possible condition. Maps showing these properties are available on this page.
Section 710.1 of the Uniform Plumbing Codes states the following. Backflow Protection. Fixtures installed on a floor level that is lower than the next upstream manhole cover, or the public or private sewer, shall be protected from backflow of sewage by installing an approved type of backwater valve. Fixtures on such floor level that are not below the next upstream manhole cover shall not be required to be protected by a backwater valve. Fixtures on floor levels above such elevation shall not discharge through the backwater valve. Cleanouts for drains that pass through a backwater valve shall be clearly identified with a permanent label stating "backwater valve downstream."
Whose Responsibility Is It?
Prevention of sewer backups is a shared responsibility. Backwater valves, when required by the plumbing code, are to be installed, owned and maintained by the property owner. Failure to comply with applicable plumbing codes could result in increased liability exposure on the part of property owners. DPU will work with customers to determine the applicability of this code provision and their potential risk. You are encouraged to contact us if you have any questions or concerns so that we can work together to ensure your property is protected.
