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Backflow testing in Sterling, from Sterling Park’s older yards to the 1990s streets of Cascades and Lowes Island, done the way Loudoun Water wants it.
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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 Sterling
Across Loudoun County, the typical owner’s house was built in 2003. In the Sterling Census place, around Sterling Park, it’s 1979. That gap shapes what a backflow test here turns up. On a newer Loudoun street the device is often a few years old and came with the house. In Sterling it’s more likely one an owner added long after the house went up, or an original that has sat through thirty winters or more.
More than four homes in ten in the Sterling Census place, and about four in ten in Sugarland Run, went up before 1980, when a lawn sprinkler system usually wasn’t part of a new house. If yours has one, a later owner put it in, and the device sits wherever their installer chose: beside the foundation, in the basement where the sprinkler line leaves the house, or in a box in the yard. Know where yours is before the tester comes.
Countryside, Cascades and Lowes Island are younger but not new: about eight homes in ten in Countryside, and most in Cascades and Lowes Island, were built in the 1980s and 90s. Where the sprinklers came with the house, the PVB by the foundation may still be the original. A device that age usually fails on one worn part rather than the whole body, so it can be rebuilt right where it stands. One that can’t is replaced, and the new one is tested when it goes in.
Loudoun Water takes the report from the tester, not from you. When your tester files on Loudoun Water’s online test report, a copy is emailed to you and to the utility automatically, so if nothing reaches your inbox after the test, ask for it. The rest of Loudoun Water’s rules are on our Loudoun County backflow page.
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 |
|---|---|---|---|---|
| Sterling | 1979 | single-family houses, about 5 in 10 | electricity, about 5 in 10 | A sprinkler system or pool added later, where there is one. |
| Lowes Island | 1996 | single-family houses, about 6 in 10 | gas, about 7 in 10 | Mostly the association’s sprinklers, plus any yard system an owner added. |
| Cascades | 1996 | townhouses, about 4 in 10 | gas, about 8 in 10 | Sprinklers added by an owner, pools and hot tubs. |
| Sugarland Run | 1983 | single-family houses, about 6 in 10 | gas, about 5 in 10 | Sprinklers added by an owner, pools and hot tubs. |
| Dulles Town Center | 1998 | condo and apartment buildings, about 5 in 10 | gas, about 9 in 10 | The building’s fire line, tested by the association. |
| Arcola | 2017 | townhouses, about 5 in 10 | gas, about 8 in 10 | Mostly the association’s sprinklers, plus any yard system an owner added. |
| Oak Grove | 2005 | townhouses, about 8 in 10 | gas, about 9 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
If a past owner put in a sprinkler system and nobody turns it on now, the device still owes Loudoun Water a yearly test as long as it’s connected. The one way off that list is to have the supply cut and permanently capped by a plumber or a certified irrigation contractor. Paying every spring to test zones you’ll never water? Ask about capping it.
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
Loudoun Water wants testable backflow devices tested every year by a certified tester. A device that fails has 30 days from Loudoun Water’s notice to be repaired and retested, and one taken off for the winter is retested when it goes back on. 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.
Loudoun Water’s test sheet has a line for the gauge’s calibration date, and the utility checks it. A kit has to be calibrated at least once a year, never more than 12 months apart, and a test run on one past its date is void, so the device has to be tested over. Ask when you book; it’s a one-line answer.
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.
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Questions
Yes. Loudoun Water’s program has testers send in failed reports too, and then the passing one once the device is repaired and retested. Its repair deadline runs from its own notice, not from the test date, and the quickest way to close it out is a repair and retest on the same visit, where the device allows one.
Loudoun Water says a device that comes out and gets swapped for a new one has to be installed by a master plumber, and the new one is tested before it counts. Its test sheet asks for the old device’s serial number beside the new one’s, so the utility’s records follow the swap.
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 Sterling 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.