Backflow prevention: Why you should care

February 10, 2017

Some homes have them, many businesses have them, and most if not all industrial, foodservice, and manufacturing facilities have them…or they should! And few people pay any attention to them until they either make a wet mess on the floor, or fail completely. What are they? ‘They’ are backflow preventers, and they are an important tool used to protect the quality of your drinking water. A backflow preventer keeps potentially harmful contaminants from being siphoned into the drinking water supply should a decrease in water pressure occur.

Cross-contamination of water supplies have happened for many decades, often with fatal consequences, but it wasn’t until World War II that an organized effort to prevent it began. A Navy supply ship docked in southern California was found to have harbor water in its potable water tanks. An investigation determined that a cross-connection between the dock water system and the harbor caused the storage tanks to fill with undrinkable water.  Concerned officials approached the University of Southern California and asked for their help in devising a way to keep this from happening, and thus was born the backflow preventer. Properly installed and maintained, it provides redundant protection against back-siphonage.  Small businesses may have multiple devices, maybe one at the ice machine and another at a soda dispenser, for instance, They might look similar to this one.


You likely have devices designed to protect against backflow in your home, and you may not even know it! If you have a water meter in your home, chances are there is a check valve built into the meter itself. Your bathtub likely has one built in….see that overflow hole under the bath spout? That serves as an air gap, which separates the water fill from the water in the tub, so you don’t end up with ice cubes that taste like Junior’s Mr. Bubble. If you heat your home with hot water or steam, your boiler likely has its own backflow prevention device installed on the water feeder line, which keeps the black, smelly water in your boiler and radiators from creeping into your home’s water supply and ending up in the washer with your white bedsheets. Occasionally you may see a few drops of water coming out of the vent. This may be normal: if there was a great drop in city water pressure, if the fire department opened a hydrant close by, or if some work was done to your plumbing system, the pressure drop may be enough to activate the safety mechanism in the valve. This is just the valve doing its’ job, and it should stop shortly. If it doesn’t stop dripping, the valve may be fouled. Call Adirondack Mechanical for service, and we’ll clean it or replace it if necessary.  It may look like this one.9dYour outside hose faucets and laundry tub spouts likely have a vacuum breaker built right in as well. If they don’t, these are inexpensive and easy to install. This device allows a small amount of air to enter the line above the hose to force water in the hose to drain out, thus eliminating a possible cross-connection. It just screws onto the threads where you would attach your hose. It looks like this.8a-tif

These are easy ways to prevent household chemicals such as insecticides, lawn or pool chemicals, detergents, etc. from accidentally getting sucked into your house’s water system and possibly contaminating your family’s drinking water. There’s usually no service required to keep them operating well. A wise move is to NOT submerge the end of any hose in any bucket, basin, or pool. If you leave an air gap — a space of air between the outlet of the hose and the water level in the container — you have created a simple and very effective backflow preventer

Larger devices such as those in a restaurant, factory, or medical clinic, however, require annual testing by a certified backflow prevention technician. New York state law mandates a test report be submitted annually to the organization supplying the water to the facility, verifying the device passes the test. If the device fails the test, it can often be cleaned or repaired, but occasionally it must be replaced by a certified backflow prevention technician. Adirondack Mechanical has certified backflow prevention technicians with the training and materials to properly test, maintain, and repair all your backflow prevention devices. We submit a completed test report to the municipal water department to satisfy state requirements, and deliver one to you for your records. Call our office at 883-3077 to schedule the service or annual testing of your backflow preventers today!

Watch as a large backflow preventer is repaired and tested….