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Which MD Counties Require Homeowners To Test Their Backflow Preventers?

Clean, healthy water is important for both your family and the entire community. One of the most significant dangers to a public water system is backflow, or contaminated water entering the potable water system. Special devices called backflow preventers are used to stop contaminated water from flowing back into the public water system, and they are required on most new or recently remodeled homes in Maryland. For homes with testable backflow preventers, they should be inspected and tested annually — and in Anne Arundel County and Montgomery County, this is required by law.

How Does Backflow Contaminate Water Systems?

Without a backflow preventer, any loss of pressure in the public water supply or your home’s main water line could allow contaminated water to enter the potable water system. This can happen in a variety of ways. One of the most common is through a submerged hose. If a hose is placed in a bucket of contaminated water and a water main nearby breaks, the fluid in the bucket could be siphoned into the public water system.

Another common way contamination occurs is when the pressure of the public water system is reduced due to a fire nearby, which creates a significant demand on the system. When this happens, any pumps for a boiler, a chilled water system, or chemical tank in a building could overcome the public water pressure and force contaminated water into the public supply. Backflow preventers are designed to eliminate the chances of this happening by closing check valves or allowing air into the line to prevent siphoning.

Have more questions about backflow preventers? Contact Water Doctor online or give us a call at 301-953-2846!

Which MD Counties Require Backflow Preventer Testing?

In most areas of Maryland, backflow preventers are required on all new homes, as well as those that have been recently remodeled. They are also required for all residential irrigation and sprinkler systems. There are several types of backflow preventers, including:

  • Testable backflow preventers: The most common testable designs include reduced pressure zone models and dual check valve models. Both should be tested annually by a professional to ensure they are functioning correctly.
  • Non-testable backflow preventers: Typically, these models are dual-check valve designs that have a fixed five-year design life, after which they should be replaced.
  • Vacuum breakers: Designed for hose bibbs, laundry tubs, and some appliances, these simple devices prevent siphoning by allowing air into the line. They typically last for many years without the need for replacement.

Schedule Backflow Preventer Testing Today!


Choose Water Doctor for Backflow Preventer Testing in MD

When you need to have your backflow preventer tested, you can count on our team at Water Doctor for fast, professional service. As a licensed plumbing contractor, we have the credentials required to provide full inspection and testing of all common backflow prevention devices. Since 1979, our team has been providing comprehensive water quality testing and treatment services throughout Maryland, and we serve both residential and commercial customers.

To schedule an appointment for backflow preventer testing, call us today at 301-953-2846 or contact us online!

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Anne Arundel | Howard | Baltimore | Frederick | Montgomery | Carroll | Charles | Calvert | Queen Anne's | Harford