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Backflow testing in Woodbridge, from Lake Ridge to Leesylvania: we test the device, fix it if it fails and make sure Prince William Water gets the report.
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Our plumbing team in front of three of our vans.
Licensed and insuredVirginia Class A contractor #2705192276
24/7 emergency serviceOften same-day, and we will tell you honestly when we can get there.
Our own plumbers, our own trucksNobody here is a subcontractor with a magnet on the door
The price is settled before the workYou see the number in writing before anything is taken apart
What it costs
How many devices you have and what kind they are decide the number, so there isn’t one figure that fits every house. You get one flat price per device when you book, before anyone comes out.
Yearly backflow test
One flat price per device, given when you book
Repair or rebuild after a failed test
Priced in writing before any work
New backflow preventer, installed
Priced in writing before any work
A device that fails is priced in writing before any work. Most can be rebuilt with new springs, seats or rubber parts; a body cracked by a freeze gets replaced. Either way it’s tested again afterward, which Virginia requires.
The national numbers, and what moves a price up or down, are in our backflow testing cost guide.
What’s different in Woodbridge
Prince William Water’s test report form is made for the tester to send in, and most testers do. The utility still puts the job on you: the owner gets a copy of the approved results and is responsible for the forms reaching its Cross Connection Coordinator. So after a test in Woodbridge, ask whether the report went in and keep your copy. If a second notice shows up anyway, that copy and its date settle it.
Where the devices are depends on when the street went in. Leesylvania and County Center are the newest ground with a Woodbridge address, about eight homes in ten built since 2000, and that’s where lawn sprinklers put in by the builder, with a PVB standing beside the foundation, turn up most. In Dale City, where about four homes in ten predate 1980, sprinklers were usually added later by an owner, so whether your house has a device at all depends on who lived there before you.
Lake Ridge is more than four homes in ten townhouses. A townhouse row rarely has its own sprinkler system; the grass out front usually belongs to the association, and so does the device that waters it. If a notice there is addressed to you, a past owner most likely added sprinklers to the yard, and it’s worth a walk around the foundation before you book.
The county rule that catches people comes in the fall. Prince William County code puts a backflow device on every lawn sprinkler system, and a system winterized with antifreeze instead of compressed air can only have an RPZ on it. A PVB with antifreeze behind it is a code problem, so ask your irrigation company how they winterize before the first freeze. Our Woodbridge and Prince William backflow guide has more on the notice and the county rules.
Neighborhood by neighborhood
Census figures for the owner-occupied homes in each place, and what usually brings the test notice to houses like these.
| Place | Median home built | Most homes are | Heated with | What usually needs the test |
|---|---|---|---|---|
| Dale City | 1983 | single-family houses, about 7 in 10 | gas, about 7 in 10 | Sprinklers added by an owner, pools and hot tubs. |
| Lake Ridge | 1985 | townhouses, about 4 in 10 | electricity, about 5 in 10 | Mostly the association’s sprinklers, plus any yard system an owner added. |
| Woodbridge | 1976 | single-family houses, about 4 in 10 | gas, about 5 in 10 | A sprinkler system or pool added later, where there is one. |
| Leesylvania | 2006 | single-family houses, about 4 in 10 | gas, about 6 in 10 | Lawn sprinklers the builder put in, and their device. |
| Potomac Mills | 1988 | single-family houses, about 6 in 10 | electricity, about 7 in 10 | Sprinklers added by an owner, pools and hot tubs. |
| County Center | 2006 | townhouses, about 4 in 10 | gas, about 6 in 10 | Mostly the association’s sprinklers, plus any yard system an owner added. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
About a third of Leesylvania’s homes and close to half in the Woodbridge Census place are rented, and the notice goes to the address. If you rent the house out, ask your tenants to pass along anything from Prince William Water: a device that misses its date is the owner’s to sort out.
A letter from the water utility with a date on it means there’s a testable device on your line, usually on the lawn sprinklers, and its test is due.
On an RPZ, a little water when the pressure jumps can be normal. A steady stream from the opening underneath means a check valve isn’t sealing, and it won’t pass.
Before the first hard freeze
A device that sits full of water all winter is the most common reason it fails the spring test. Around here, get this done by the end of October.
On most houses it’s outside by the foundation: a brass valve on two pipes standing out of the ground, with a cap on top. That’s a PVB. An RPZ or double check may sit in a basement or a box in the ground instead.
Turn off the valve that feeds the sprinklers, usually in the basement or utility room just past the main shutoff. Leave the rest of the house on.
Most systems here get blown out with compressed air so nothing sits in the lines or the device. If yours hasn’t been, that’s the step that matters.
Set the device’s two shutoff handles and its little test cocks about halfway, near 45 degrees, so no pocket of water stays trapped inside to freeze.
An insulated cover helps a PVB through the winter. On an RPZ, never block the relief valve opening underneath: it has to be able to dump water.
Some owners bring the device inside for the winter. Check the rules first: Loudoun Water wants a device that came off tested again when it goes back on, and Fairfax County wants it back on before your testing month.
Not sure it was drained, or saw water coming from the cap when the sprinklers ran? Call us. We’ll look at it, and if it cracked, you get the reason and a price before anything gets replaced.
Who sends the notice
Prince William Water mails a notice when a device comes due each year. Its test report form is made for the tester to send in, but the owner gets a copy of the approved results and is responsible for getting the forms to the utility’s Cross Connection Coordinator. Source.
County code says every lawn sprinkler system needs a backflow device, and a system winterized with antifreeze can only use an RPZ. Source.
Our Virginia Class A contractor license, 2705192276, is on the side of the van.
Choosing a tester
Questions to ask anybody who offers to test it, us included.
Because Prince William Water holds the owner responsible for the paperwork, the tester’s follow-through matters more here than in most places. Ask who sends the results form, get your own copy, and check that the device’s location and serial number are on it.
Since January 1, 2023, Virginia only accepts tests from a DPOR-certified Backflow Prevention Device Worker, and some places keep a list of their own on top. Ask to see the certificate before the gauge goes on.
Some utilities take it from the tester and some want it from you. Ask which, and keep a copy either way, so you can show the date if a second notice turns up.
Ask for the reason and a written price before anything gets taken apart, and whether the retest is part of it. A failed device runs on a deadline, so a tester who can also fix it saves you a second trip.
Two of our crew going over a work order before the day's calls.
From our Google reviews
5.0 stars across 1,131 reviews. Read them on our reviews page.
Tyson was wonderful; professional, very knowledgeable, thorough and fast. He was great at telling me about what was needed, and I very much appreciated that. For the next plumbing problem we have, I will have SwiftPro on speed dial.
Where we work
Next door to Woodbridge: Manassas, Annandale, Fairfax, Bristow and Centreville.
Questions
The utility’s results form is built for the tester to send in, but Prince William Water makes the owner responsible for it reaching its Cross Connection Coordinator. Ask your tester to confirm it went in, and keep the copy of the approved results you’re given.
Only behind an RPZ. Prince William County code allows antifreeze winterization with one device type, the RPZ, so a system with a PVB gets blown out with air instead. Not sure which you have? The PVB is the one standing up out of the ground with a cap on top.
One flat price per device, given when you book, before anyone comes out. How many devices you have, and whether one needs a repair, is what moves it. Our cost guide has the national numbers.
About 30 minutes a device. The water is off for a few of those minutes while the gauge readings are taken.
Ready when you are
Call, or send the form at the top. Have the notice handy: how many devices it lists and the date on it are what we need.
SwiftPro Heating, Cooling & Plumbing
4230 Lafayette Center Dr N, Chantilly, VA 20151
44679 Endicott Dr, Suite 211, Ashburn, VA 20147
Virginia Class A contractor license #2705192276
SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Woodbridge and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 1,131 reviews on Google, Angi, Yelp, the BBB and Facebook. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
From SwiftPro Heating, Cooling & Plumbing in Chantilly. Housing figures are the Census Bureau’s American Community Survey, 2020 to 2024, for each place named; permit, water and sewer facts link to each office’s own page and were checked in September and October 2026.