Backflow Prevention


The Hooksett Village Water Precinct maintains an aggressive backflow prevention program to help protect its customers from unwanted contamination.  Backflow is when water flows in the opposite direction from normal due to a change in pressures.  During backflow, contaminants may enter your building and the water system through cross-connections.  Cross-connections may occur anywhere that the drinking water plumbing is in contact with potential sources of contamination.

Cross-connections can occur in many residential, commercial and institutional settings and must be adequately protected with air gaps in the plumbing or special backflow prevention devices.  These devices must be approved by the Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California.  Devices that are granted approval by the Foundation are extremely dependable at preventing flow reversals.

The backflow prevention program is mandated by the U.S. Environmental Protection Agency and the N.H. Department of Environmental Services.  There are over 300 backflow devices in the Precinct.  About half of those are located at commercial, institutional or multi-family residential properties in fire sprinkler systems or domestic drinking water applications.  The remaining devices are located in irrigation systems serving commercial, institutional and residential properties.

Backflow devices are owned and maintained by the customer.  Testing is required, at a minimum, once or twice per year depending on the type of device used.  Testing is performed by our certified backflow testers and subcontractors, and billed to the customer.  Scheduled appointments for the testing are usually not necessary, since commercial properties are tested during normal business hours and most residential properties have irrigation system protection devices located on the outside of the building.

All properties with irrigation systems and all commercial and industrial buildings require protection.  The lack of the proper backflow device at your property could impact the health of your family, employees or neighbors.  Please contact us if you have any questions about the need for devices, or for additional information on cross-connection control and backflow prevention for your home or business.

Credits:  Portions of the above information were adapted from the web pages of the Pennichuck Corporation and Manchester (NH) Water Works.


HVWP Cross-Connection Control Program Bylaw

HVWP Backflow Device Policy for New Irrigation Systems

HVWP Backflow Device Policy for Existing Non-Compliant Irrigation Systems

USC List of Approved Backflow Prevention Devices

HVWP Summary of Device Types Required & Customer Responsibilities
Backflow Preventer Selection Guide (used with permission from Sprinkler Warehouse)
Town of Lincoln’s “Cross Connections in Household Plumbing”
Watts’ “Stop Backflow News! Case Histories and Solutions”
NESC Backflow Prevention Device Illustrations