What Is Backflow Prevention and Does Your Home Need It?

Backflow prevention isn't the most glamorous plumbing topic, but it's one of the most important — especially if you have an irrigation system, a swimming pool with an auto-fill line, or any connection between your home's plumbing and an outside water source. In New York State, it's also a regulatory requirement for many residential properties.

Here's what backflow is, why it matters, and what Rochester-area homeowners need to know.

What Is Backflow?

Your home's plumbing is designed to move water in one direction: from the municipal supply into your home and out through the drain. Backflow happens when water flows in the wrong direction — from your home's plumbing back into the public water supply. This can happen due to a sudden drop in water pressure in the supply line, such as when a water main breaks nearby or when firefighters draw large volumes of water from a hydrant.

When backflow occurs, contaminated water — water that has been in contact with fertilizers, pesticides, pool chemicals, or other non-potable sources — can be pushed back into the public drinking water supply. This is why municipalities take it seriously.

What Is a Backflow Preventer?

A backflow preventer is a mechanical device installed on your water line that allows water to flow in only one direction. It physically prevents the reversal of flow, protecting both your household water and the public supply from contamination. There are several types — pressure vacuum breakers, double check valves, and reduced pressure zone assemblies — and the right type depends on the specific application and local code requirements.

Does Your Rochester-Area Home Need One?

If your property has any of the following, New York State law or local municipal code likely requires a backflow preventer that is tested annually:

• An in-ground irrigation or sprinkler system

• A swimming pool or hot tub with an auto-fill connection

• An outdoor hose bib used with a chemical injector or fertilizer sprayer

• A boiler with a direct water connection

• Any secondary water supply connection

Many homeowners with irrigation systems aren't aware the testing requirement exists until they receive a notice from their municipality. Annual testing documentation is required in most jurisdictions and must be submitted to the local water authority.

What Does Annual Testing Involve?

Testing a backflow preventer requires a certified tester — not just any plumber, but one specifically certified by New York State for backflow testing. The process involves isolating the device, attaching test equipment to measure the differential pressure across the valve, and verifying that it meets the required standard. John Lockwood Plumbing employs NYS certified backflow testers and can handle testing, documentation, and any repairs or replacements the device needs.

Testing typically takes 30 to 60 minutes and should be scheduled in spring, before irrigation systems are activated for the season.

What Happens If You Don't Get It Tested?

Beyond the regulatory compliance issue, an untested backflow preventer may have failed without your knowledge. A device that isn't working isn't protecting your water supply — or the community's. In some municipalities, failure to submit testing documentation can result in a fine or, in extreme cases, shutoff of your water service.

The testing itself is straightforward and not expensive. It's one of those maintenance items that's easy to stay on top of once you've set up a routine.

John Lockwood Plumbing provides backflow installation, testing, and certification throughout Rochester, Canandaigua, and the surrounding area. Call (585) 265-0736 to schedule your annual test.