Great Falls, VA · Serving the Potomac, MD service area
Emergency Plumber for Great Falls Homes: Sewer Service Area, Septic and Well Come First
Much of Great Falls lies outside the county sewer area, and its lots are big. Use this page to sort out your own setup before you pick up the phone.
Most of Great Falls lies outside the sewer service area
Great Falls is a low-density part of Fairfax County. Using the county's GIS layer, about 79 percent of the Great Falls census area lies outside the Approved Sewer Service Area and about 21 percent lies inside. That is the owner's arithmetic on land, not a count of homes on septic.
Fairfax County's land use plan for the Upper Potomac area says some sectors are outside that service area and planned for uses that do not require public sewer. Your own lot is what matters, and the map cannot settle it.
| Setup | First call for a backup | Plumbing scope |
|---|---|---|
| County sewer | The county if the main may be blocked, then a plumber | Drains, laterals, fixtures |
| Septic tank and field | A septic contractor | Interior plumbing only |
| Private well | A well contractor | Interior fixtures, heater, piping |
Fairfax County's Health Department, 703-246-2201, regulates septic systems and private wells, and its pages call for pumping a tank at least every five years. On septic, call a septic contractor. On county sewer, clearing a slow drain inside the house is the plumber's part.
County sewer backing up: in Fairfax the county gets the first call
Fairfax County's order is the reverse of what homeowners expect. Its Public Works page says to call the county before calling a plumber when you have a sewer backup and think the problem is in the county sewer main. The 24-hour line is 703-323-1211.
If only one fixture backs up, such as a toilet, tub or sink, the county page says you may need a plumber. County Code 65-6-1 puts the private lateral, the pipe from house to main, on the owner.
- Several fixtures backing up at once: call the county line first.
- One fixture backing up: call for a plumber.
- Keep any report the county or plumber gives you.
- Ask the plumber whether the blockage was in the lateral or the main.
A lateral that fails again and again is a different problem, covered under fixing a damaged sewer lateral.
Basement or floor wet in Great Falls?
Shut off the main if you can, then phone with your address.
Big lots, detached houses and long runs of pipe
The 2019-2023 survey puts 99.3 percent of Great Falls' 5,136 housing units in detached houses, and 95.4 percent of them are owner-occupied. Zoning is mostly the 75,000 and 36,000 square foot minimum lots of the R-E and R-1 districts, which is why driveways and service lines run long.
Distance changes the repair. A leak under a lawn or a driveway is harder to find than one inside a wall, and a longer line costs more to replace than a short one. Get the footage on paper before agreeing to a price.
- Distance from the street to the house?
- Location of the main valve and cleanout?
- Is the line under pavement or turf?
- One section, or the entire run?
A line you cannot see needs locating a leak under a lawn before anyone digs. Call 811 first. Virginia law requires a locate request before any excavation.
Great Falls on the map: Georgetown Pike and ZIP 22066
Great Falls sits across the Potomac River from Potomac, MD. The Census Bureau puts about 95 percent of its land in ZIP 22066. We check each address when you call.
Gas, electric, propane or oil: four fuels in one town
The survey estimates 42.9 percent of Great Falls homes heat with utility gas, 42.7 percent with electricity, 7.7 percent with propane and 5.1 percent with fuel oil. The heating figure describes furnaces, so check the nameplate on the tank itself.
Fairfax County says installing or replacing a gas water heater needs a permit, even a like-for-like swap. Owners may pull permits in their own name, but the county strongly recommends a licensed contractor do it. Land Development Services answers questions at 703-222-0801. Oil-fired boilers are heating work, not plumbing.
Start with whether the tank can be saved. If a gas line change is part of the job, gas piping behind the heater explains who handles what. If you smell gas, leave first and then dial 844-927-4427 for Washington Gas.
Houses from the 1970s and 1980s: what the pipes may be
About 38 percent of Great Falls homes went up in 1979 or earlier, and 26.4 percent more in the 1980s. That is a large block of houses now past 35 years old.
Age alone does not condemn a pipe. A plumber should look at the material, the number of repairs and the water quality before recommending anything. Fairfax Water lists its hardness at 5 to 10 grains per gallon, which leaves scale on heating elements and aerators.
- What is the supply pipe made of, and where does it enter the house?
- How many leaks has the house had in the past few years?
- When was the water heater last flushed?
- Is the problem one run or several?
Several repairs in the same house can point to replacing worn supply pipes. Fairfax County's frost depth is 24 inches, so buried lines belong below that.
Septic and well homes: where the plumber's work stops
Inside a septic or well house the plumbing is ordinary: heater, fixtures, supply lines and the drains leading out to the tank. Outside, the tank, the field and the pump belong to other trades.
Name your system when you phone. Skip chemical drain cleaner on a septic line until the septic contractor weighs in.
Meter problems are different. Fairfax Water owns the meter, and its after-hours line for street-side leaks is 703-698-5613. A leak after the meter belongs to the owner. A split pipe in cold weather starts with the shutoff, not the meter.
Great Falls questions on sewer service, septic and wells
Is my Great Falls house on county sewer or septic?
Much of Great Falls sits outside the county's Approved Sewer Service Area, so septic and well are common, but the map says nothing about your lot. Fairfax County's Health Department, 703-246-2201, can tell you what applies to your address.
Do you work on septic tanks and wells?
Not the tank, the field or the well. Those belong to septic and well contractors. Inside the same house, a plumber still handles the heater, fixtures and supply lines.
My sewer backs up in more than one drain. Who do I call first?
If the house is on county sewer, With several drains backing up, the county asks to hear first, at 703-323-1211 day or night. One backed-up fixture goes to a plumber.
Which ZIP code is Great Falls?
Nearly all of Great Falls, about 95 percent of its land by Census count, falls in ZIP 22066. We check the address you give.
Water where it should not be in Great Falls?
Shut the nearest valve, then phone. Mention county sewer or septic and your address.