Backflow Testing

Protect your water system from contamination

If you’ve received a backflow test letter in the mail or are concerned that your backflow prevention device might need to be repaired, you should call a reliable plumbing company right away. Water Doctor of Washington Plumbing Services offers backflow replacement and testing for clients in Southwest Washington.

Now serving Lewis, Thurston, Cowlitz, Clark, and Mason Counties.

What is a Backflow Device?

A mechanical backflow device prevents wastewater from flowing back into your plumbing and up through your sink or toilet, in a process known as backflow.

If your backflow prevention device is damaged, nonpotable water could enter your home, damage your property and contaminate your drinking water. This is why it’s crucial to call a plumber for backflow replacement as soon as you learn there is a problem with your device.

Why backflow testing important?

Since backflow devices are comprised of internal seals, springs, and other moving parts, they can break down or corrode over time. Backflow testing is crucial to ensuring that your device is in working order.

What is backflow?

Backflow is the reversal of water flow from its normal or intended direction. When a customer is connected to a water utility the intention is for water to flow from the water utility to the customer. However, the flow can reverse leading to potentially contaminated water from the customer flowing back into the water distribution system. This situation can be dangerous as it could contaminate the water supply. There are two kinds of backflow, back siphonage, and back pressure.

What is backpressure backflow?

When downstream water pressure exceeds the positive pressure of the incoming water supply then backpressure backflow can occur. Boiler pressure among other things can cause this effect. Proper installation of a backflow prevention device will prevent contamination of the water source from backpressure backflow.

What is back-siphonage backflow?

Back siphonage backpressure is cause by negative pressure or a vacuum created by the supply piping. The effect created is like drinking water through a straw. This can occur when there is a draw on water from the supply line, such as nearby fire-fighting or broken water main.

What can you Expect?

Our Certified Backflow Assembly Tester will test your backflow prevention valves. If a valve fails the test, we will repair and retest it. We then file all the paperwork required by the state of Washington.

We can just place you on our worry-free automatic testing schedule whenever you’d like.

Request an Appointment

Backflow Test Request Form

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Backflow Blog

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Backflow Service Area

Established in 1965 as Rainwater, and later as Water Doctor in 1997, our company has a long-standing tradition of serving the community. In 2023, we combined to form Water Doctor of Washington. As a local, family-owned business headquartered in Chehalis, WA, we are your trusted source for water treatment and plumbing solutions in Washington State.

This map indicates our Backflow service area.