Well and septic in Fairfax CountyWhat is due, what to check before you buy, and what to have ready to sell
Pick what the house has. See when the tank is due to be pumped and the water due to be tested.
Big lots, their own water and sewer· Great Falls, Fairfax County
Rules: Fairfax County’s own pages and the Code of Virginia, October 30, 2026. Pictures: artist’s renderings of real places.
The checker
Is the septic tank due? Is the water tested?
Not sure what the house has? Type the address into the Fairfax Lot Check: it shows septic tank, drain field and well records on the county’s map. Fairfax County rules only; nothing you pick is saved or sent.
Pick what you are doing and what the house has. See what is due, and your to-do list.
Updated October 30, 2026Rules read on Fairfax County’s pages and the Code of Virginia, October 30, 2026A 30-second checker, plus a 5-minute read
Quick answer
Thousands of Fairfax County homes run on their own septic tank and well, most of them on the big lots of Great Falls, Oakton, Fairfax Station and Clifton. The county requires the septic tank to be pumped at least every 5 years, and the Health Department tells well owners to test the water every year.1 Virginia doesn’t require a septic inspection at sale and the seller makes no promises about the system, so the checking is up to the buyer.5 Since July 1, 2026, a septic inspector has 10 business days to deliver the report.7 Use the checker above to see what is due.
Well and septic in Fairfax County, in six numbers
County rules and records, 2026
Records are septic tanks and wells on the county’s map, read October 30, 2026.
Where
Where Fairfax homes run on well and septic.
Septic tank and well records on the county’s map, by ZIP code.
In shortMost of the county is on public sewer, but 28% of its land lies outside the sewer service area. Great Falls has the most septic tanks and wells; Clifton has more wells than tanks.
Septic tanksWells
Records on the county’s map, not homes: one house can have a tank and a well, and the parcel count includes land without a house. Only the Fairfax County part of each ZIP code. Read October 30, 2026.
How it works
Tank, drain field, well.
What is in the yard, and what each part needs.
In shortTank, drain field, well. The tank needs pumping every 5 years; the well water needs a test every year.
The rules
What Fairfax County and Virginia require.
The rules behind the checker, with the source for each.
In shortOne county rule (pump every 5 years), one yearly habit (test the well) and one state trap (a repair waiver ends at sale).
Pump every 5 years
Chapter 68.1 of the County Code requires every septic tank to be pumped at least once every 5 years. The contractor enters each pump-out in PLUS, so you can check the date.1
Alternative systems: a yearly check
A system with added treatment is inspected every year by a licensed operator and sampled every 5 years; the operator sends the report to the Health Department.1
Waivers end at sale
A state waiver that let an owner repair a failing system without added treatment is recorded and ends when the home is sold, with a few exceptions such as foreclosure and estates.6
Test the well every year
For bacteria and chemicals, and again after any change in the water’s smell, taste or look. The Health Department takes samples on request.1
Adding a bedroom
On a well or septic, the Health Department reviews a building permit for an addition or alteration first: the system has to handle the added bedroom.4
New well or system: the fees
A new well permit is $500 (one-time). A new septic system permit is $200 county plus $215 state plus $10 (one-time); an alternative system adds a $200 plan review (one-time).2
Buying
Buying a house on well and septic, step by step.
From before the offer to settlement.
In shortVirginia leaves the checking to the buyer. Give the septic report 10 business days, test the water, and ask about waivers.
- 1Before you offer
Find out what the house has
Type the address into the Fairfax Lot Check for septic, drain field and well records, and ask the seller for pump-out receipts, well tests and any repair permits.
- 2In the contract
Leave room for the septic report
The inspector has 10 business days to deliver the written report unless both sides agree otherwise in writing. Set your inspection period to fit, or agree on a faster report.7
- 3Before the contract is accepted
Watch for a waiver disclosure
If the system was repaired under a state waiver from added treatment, the seller must hand you a separate written disclosure. The waiver ends at sale, and the added treatment can fall to you.6
- 4
- 5Before settlement
Settle what is due
If the 5-year pump-out is due, ask the seller to pump it, and check that the contractor entered it in PLUS.1
Public sewer
Can you switch to public sewer?
It depends on two things: the sewer service area and the distance to a main.
In shortOnly inside the approved sewer service area, with a main close enough. You pay for any extension.
Inside the approved sewer service area, with a county sewer main within 300 feet of a single-family home: sewer counts as available. A licensed plumber gets the permit to connect, and the county’s connection charges are paid first.3
A sewer line can be extended up to 400 feet across the service area line (and no deeper than a 12-foot manhole). The owner who asks pays for the extension.3
The Board of Supervisors must expand the service area. It might for a failing system that the Health Department confirms is a real health risk; it has historically not done it for new homes or redevelopment.3
Switching to sewer also means closing the old septic system properly; the Health Department handles abandoning a septic field.3
Selling
Selling a house on well and septic.
What to have ready before you list.
In shortA fresh pump-out record and a recent water test answer the first two questions a buyer asks.
Pump before you list, if it’s due
A pump-out record in PLUS from the last 5 years answers a buyer’s first question, and it is the county rule anyway.1
A waiver? Disclose it first
If the system was repaired under a state waiver, give the buyer the separate written disclosure before you accept a contract. Late, and the buyer can end the contract.6
Test the well
A recent lab report for bacteria and chemicals saves a week in the buyer’s inspection period.1
Gather the records
Permits for the system and well, pump-out receipts, repair records. Find older permits and your free plat: pull your permit history.
Questions
What people ask about well and septic.
How often do you have to pump a septic tank in Fairfax County?
At least once every 5 years. Chapter 68.1 of the County Code requires it for every septic tank, and the contractor enters the pump-out in the county's PLUS system. If you don't know when it was last pumped, the Health Department says it is time.
How do I find out when a septic tank was last pumped?
Ask the seller for the receipt, and look up the property in PLUS, the county's permit and records system, where the pump-out contractor enters each pump-out. The Health Department has a short video on how to check it.
Does Fairfax County require a septic inspection when a house is sold?
No. Neither the county nor Virginia requires one at sale. Virginia's disclosure statement says the owner makes no representations about the wastewater system and the buyer should do their own checking before settlement, so most buyers hire a septic inspector.
How long does a septic inspection take in Virginia?
Since July 1, 2026, the inspector's written report is due within 10 business days of the start of the inspection unless both sides agree otherwise in writing. That is about two weeks on the calendar, so set your inspection period to fit.
Should I test the well water before buying a house?
Yes. The Health Department tells well owners to test every year for bacteria and chemicals, and after any change in smell, taste or look. A test before you buy tells you what you are getting. The Health Department takes water samples on request.
Can I connect a house on septic to public sewer in Fairfax County?
Only if the house is in the approved sewer service area and a sewer main is close enough: within 300 feet of a single-family home counts as available, and a line can be extended up to 400 feet across the service area line. You pay for the extension. Farther out, the Board of Supervisors must expand the service area, which it has historically not done for new homes or redevelopment.
What is a septic waiver, and why does it matter when buying?
When a failing system is repaired, the owner can get a state waiver from added treatment or pressure dosing. The waiver ends when the home is sold, so the buyer may have to add that treatment. The seller must disclose it in writing before a contract is accepted.
Can I add a bedroom to a house on septic?
Only after the Health Department reviews it. In Fairfax County, a building permit for an addition or alteration goes to the Health Department when the home is on a well or septic, because the system has to handle the added bedroom.
Your next step
Looking at a house on a big lot, or selling one?
Tell me what you are after: room and privacy in Great Falls or Clifton, or selling a house on well and septic. I will check the records with you and set the inspection period so the septic report fits. I answer in English or Arabic, with real numbers, not a pitch.
اقرأ دليل شمال فرجينيا بالعربية ←
وكيلك العقاري الموثوق في شمال فرجينيا.
Keep exploring
Your next pages.
Fairfax Lot Check
Type an address: septic, well, stream buffer, marine clay and more.
TownGreat Falls
Where the most septic tanks and wells in the county are.
ToolIn-law suites in Fairfax County
On septic, a suite starts with the Health Department.
GuideNew Virginia laws
The 2026 septic inspection law, and 21 more.
Keep reading
- ToolFairfax Lot CheckType a Fairfax County address: the stream buffer, marine clay, easements, historic district, zoning and sewer or septic for that lot, from the county's own maps.
- Living hereNew Virginia laws for homeowners22 new laws from the 2026 session in plain words: deed fraud alerts, roof insurance, backyard cottages, the 14-day rent notice, each with its start date.
- ToolIn-law suites in Fairfax CountyCan your house have an in-law suite or a backyard cottage? Fairfax rules and the November 17, 2026 vote, plus Loudoun, Prince William and Arlington.
- CheckWhat to fix before sellingTap what your house has: see what to fix, what to make shine and what to skip. Staging, pre-listing inspections and selling as is.