Open 24/7 for emergencies
Backflow testing in Alexandria: City homes report to Virginia American Water through BSI Online; the Fairfax County side reports to the County.
Get your price in writing
Send this and the office calls or texts you back to set a time.
We’ll call or text this number about your request. By sending it you agree to our terms and privacy policy.
Rather talk now? (703) 997-9757
5.0 stars across 1,131 reviews
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 Alexandria
Two homes with Alexandria on the envelope can answer to different backflow rules. Inside the City, the water company is Virginia American Water. On the Fairfax County side, in Kingstowne, Rose Hill, Huntington or Fort Hunt, it’s Fairfax Water for nearly everyone, and the County runs the testing. Oddly, it’s the same water: Virginia American Water buys the City’s supply from Fairfax Water, whose program manual leaves a wholesale buyer to run its own program. Your water bill tells you which side you’re on, and in 22311, which is split, it’s the fastest way to know.
Inside the City, start with the letter. Virginia American Water’s test or inspect letter lists each device: one marked Residential Dual Check never gets a gauge, only the five-year look, and anything else is testable every year. Questions about a testable device go to BSI Online, the backflow records firm the utility works with; dual checks go to Virginia American Water’s own cross connection staff.
On the county side, even the month changes with the street. Fairfax County ties each property to a testing month through its tax map grid, and that’s the month the test has to happen, every year. Most of Kingstowne is grid 91, due in July; Huntington is grid 83, October; Rose Hill is mostly grid 82, September; more than half of Fort Hunt is grid 102, April; most of Lincolnia comes due in February. Fail there, and the County’s clock is 10 business days to fix the device and test it again.
A dual check even means something different across the line. Virginia American Water may allow one where the hazard is low and has it checked every five years; Fairfax County calls it the device it most often finds installed in error and wants a testable assembly on every in-ground sprinkler system. Fort Hunt is about 98 in 100 single-family homes, so a county notice there usually means sprinklers or a pool on a private yard. More on the Fairfax County program.
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 |
|---|---|---|---|---|
| City of Alexandria | 1970 | condo and apartment buildings, about 5 in 10 | gas, about 6 in 10 | The building’s fire line, tested by the association. |
| Rose Hill | 1969 | single-family houses, about 7 in 10 | gas, about 7 in 10 | A sprinkler system or pool added later, where there is one. |
| Franconia | 1986 | townhouses, about 5 in 10 | electricity, about 6 in 10 | Mostly the association’s sprinklers, plus any yard system an owner added. |
| Fort Hunt | 1963 | single-family houses, nearly all | gas, about 8 in 10 | A sprinkler system or pool added later, where there is one. |
| Kingstowne | 1994 | townhouses, about 5 in 10 | gas, about 7 in 10 | Mostly the association’s sprinklers, plus any yard system an owner added. |
| Woodlawn | 1976 | townhouses, about 4 in 10 | electricity, about 6 in 10 | A sprinkler system or pool added later, where there is one. |
| Lincolnia | 1982 | single-family houses, about 4 in 10 | gas, about 7 in 10 | Sprinklers added by an owner, pools and hot tubs. |
| Mount Vernon | 1967 | single-family houses, about 7 in 10 | gas, about 7 in 10 | A sprinkler system or pool added later, where there is one. |
By the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
When it’s time
Inside the City, the reminder about a testable device can come from BSI Online rather than the water company, because BSI keeps Virginia American Water’s backflow records. It isn’t junk mail: after repeated requests, the utility can disconnect service.
In a condo building the fire sprinkler line and its device are usually the association’s to test, not yours. Hand the notice to the manager before you book anyone.
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.
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
Virginia American Water, the City’s water company, wants testable devices tested every year and the results reported through BSI Online. Residential dual checks, which can’t be tested, are inspected, repaired or replaced every five years. Source.
Fairfax County’s Cross Connection Program wants testable backflow devices on lawn sprinklers, fire sprinklers, pools and hot tubs tested every year by a tester on the County’s Authorized Vendor List. The tester files the report and the County emails you when it’s in; nothing after 14 days, and the County asks you to check with them. Source.
Each property gets its own testing month from the County’s tax map grid, and the report is due before that month ends. A device that fails has to be repaired or replaced and retested within 10 business days of the failed test, and one taken off for the winter goes back on before the testing month. 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.
A City result is reported through BSI Online for Virginia American Water; a county one goes on Fairfax County’s own test report, from a tester on its vendor list. A tester guessing from the address can file in the wrong place, so ask which they’ll use.
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.
Zabi helped us with a complex plumbing problem. He explained clearly the problem and gave us various repair options. He is courteous, professional and highly experienced. We recommend him!
Questions
No. City homes answer to Virginia American Water, which tracks testable devices through BSI Online and dual checks on a five-year cycle. County-side homes answer to Fairfax County, where the tester files and the month follows the tax map grid. Same water, different paperwork.
A small backflow device with no test cocks, so there’s nothing to hook a gauge to. Virginia American Water allows one where the hazard is low and wants it inspected, repaired or replaced every five years. Anything else your letter lists is testable and due every year.
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 Alexandria 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.