Public Utilities
Absolutely "NO RETURNS"

None of us want dirty or contaminated water returned into Portsmouth's water system. To help prevent contamination Public Utilities conducts a very active "cross-connection" program approved by the State Health Department.

A "cross-connection" is improperly designed or installed plumbing that can allow contaminated water to flow backwards, from a home or business, into the public water supply. This condition is called "backflow". Portsmouth's program seeks to correct cross-connections throughout the City and eliminate the potential for backflow by conducting inspections of the plumbing of new and existing businesses and industries.

A good example of a cross-connection is the typical home garden hose. We use them to water lawns, fill pools, and even mix and spray chemicals. Normally, city water pressure ensures that water only flows one way through the hose, but what would happen if there were a sudden loss of pressure? The water would begin to run back towards the city water mains. This type of backflow is called "back siphonage". Backflow can also occur if you leave your hose tap open and the hose under pressure (charged). When the sun shines on a charged hose the water in it warms and expands. This expansion can cause pressure in the hose to be greater than the city pressure. This can result in the backflow of hose water and garden chemicals from the hose end sprayer into your homes water system and even the city water system.

What You Can Do At Home

Using a hose bib vacuum breaker can prevent backflow. These small and inexpensive devices are one of the most effective measures you can take to protect our water supply. They are easy to install and can be found in most local hardware stores for around $6 each.

For additional information on Portsmouth's Cross Connection Control Program contact the Water Quality Division at 539-2201.

A typical hose bib vacuum breaker (installation is very simple - just screw it on!)

AT A GLANCE

Portsmouth's trained Water Quality Technicians conduct 2,000 inspections of new and existing businesses and industries yearly to identify and correct potential cross-connections. Over 15,000 devices have been installed by Portsmouth's businesses and industries as part of a cooperative effort to prevent backflow.