Backflow Prevention Assemblies

To protect the water system, backflow prevention assemblies (devices that prevent the backflow of water) are required for all connections that may present a potential source of contamination of the public water system. There are two kinds of assemblies installed:

  • External backflow assemblies are used to protect the public water system from possible contamination resulting from the customer’s premises.
  • Internal backflow assemblies are used to protect the customers from potentially hazardous cross connections within their own drinking water system.

Backflow Prevention Assemblies used to protect the public water system

  • To keep the drinking water safe, SAWS reviews and stamps the utility plans of each new customer for compliance with cross-connection control/backflow prevention requirements. SAWS inspects the installation, repair or replacement of external backflow prevention assemblies, and monitors and enforces the annual testing requirements for those assemblies.

Backflow Prevention Assemblies used to protect the customer’s drinking water system

Intitial permitting and inspection for backflow assemblies, including new installations, repairs and replacements, are administered through the City of San Antonio Development Services Department, 1901 S. Alamo, 210-207-1111.