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Back Flow

Long Island Back Flow Testing & Repair

New York State Certfied Back Flow Testers | Sales and Installation; from 1/2" to 8"

old water meter

Old water meter before replacement 

8 inch backflow
8" Backflow valve during repairs
back flow
Old water meter
back flowReplaced old water meter and installated new back flow valve.


Redundant Backflow Valves Side by Side so Valves can be serviced without water shutdown

meter bank
New meter bank and backflow valves. The meter bank was prefabricated to reduce the time this apartment building was without water.

What is backflow?

What is backflow?

Backflow is the undesirable reversal of the flow of water from its intended direction in any pipeline or plumbing system. Backflow is dangerous because it can allow drinking water in plumbing systems to become contaminated and unusable.

What is a backflow preventer?

Backflow preventers are mechanical plumbing devices installed in a plumbing system to prevent water from flowing backward in the system. A properly installed, tested and maintained backflow preventer at the service entrance to a building or property can reliably prevent the backflow of water of an unknown quality from flowing back into the community water system.

Is it really important to prevent backflow?

Absolutely. The New York Division of Water requires all public water systems in the Commonwealth to operate an on-going program to protect the public water supply from contamination from possible cross connections. The most effective method for the water utility to meet this requirement is to require customers to install a backflow preventer on the main supply line to their property or facility, thus protecting the community water system from any cross connections that may be present inside a customer's plumbing system. All water users benefit from an active, on-going cross connection control program that includes the installation of backflow preventers.

Why does the customer have to pay for and install the backflow preventer?

The backflow preventer is installed to protect the public water supply against possible hazards in the customer's plumbing system. The actual or potential cross connection belongs to the property owner and not to regulatory officials or the water utility. Once the water goes beyond the meter, water quality could be altered. The water utility does not want the water back, nor do the water customers want to purchase used water. If a backflow preventer is required to keep the water safe, then the person who created the cross connection (actual or potential) should purchase, install and maintain the backflow preventer.