Buying a Home With a Well or Septic System: Inspections You Shouldn’t Skip

If you’re shopping for more land in western Loudoun, parts of Prince William or areas of Fairfax like Clifton and Great Falls, you’ll likely see homes with a private well and septic system instead of public water and sewer. These systems work well when cared for, but repairs can be expensive. A few extra inspections can save you from a costly surprise.

Inspections to order

Inspection	What it checks	Why it matters
Septic inspection	Tank condition, baffles, sludge level, distribution box, drainfield	Drainfield failure is the most expensive problem
Well water test	Bacteria such as coliform and E. coli, plus nitrates, lead, pH and hardness	Safe drinking water and treatment needs
Well flow or yield test	How much water the well delivers	Enough water for showers, laundry and irrigation
Well equipment check	Pump, pressure tank and wiring	Pumps and tanks wear out over time

What a good septic inspection includes

• Locating the tank and opening it, often with pumping so the inspector can see inside.
• Checking inlet and outlet baffles and the tank for cracks.
• Looking for wet spots, odors or lush green patches over the drainfield.
• Reviewing permits and the system design on file with the health department.
• Asking how many bedrooms the system was approved for. This matters if the listing claims more.

Some homes have an alternative onsite sewage system with pumps or treatment units. Virginia requires these to be maintained by a licensed operator with regular inspections, so ask the seller for maintenance records and contracts.

Budgeting: a worked example

Say you’re buying a $900,000 home on two acres. You spend $1,200 on septic, well and water tests on top of a standard inspection (illustrative cost). The septic inspection finds a cracked baffle, a modest repair, but also a drainfield that is still working well. You negotiate a credit for the baffle and plan to pump the tank every three to five years. Without the inspection, you’d have no idea whether a far larger drainfield repair was coming.

Common mistakes

• Relying on the general home inspection alone.
• Testing water only for bacteria and skipping other common contaminants.
• Not checking the approved bedroom count on the septic permit.
• Planting trees or parking vehicles over the drainfield after you move in.
• Pouring grease, wipes or harsh chemicals down drains, which harms the system.

Living with a well and septic system

• Pump the septic tank on the schedule your inspector recommends, often every three to five years.
• Spread out laundry loads so you don’t flood the system in one day.
• Fix running toilets and dripping faucets quickly.
• Keep a map of where the tank and drainfield are.
• Test well water regularly, and after flooding or any change in taste, color or smell.
• Keep chemicals, fuel and fertilizer away from the wellhead.

Owners who follow these habits usually get many years from their systems. Keep the records, because the next buyer will ask for them.

Questions to ask the seller

• When was the septic tank last pumped, and who did it?
• Has the system ever backed up or been repaired?
• When was the well drilled, and how deep is it?
• Has the water been tested, and do you have the results?
• Is there any water treatment equipment, such as a softener or filter, and is it included?
• Are there maintenance contracts that transfer with the home?

Ask your agent to request these answers in writing during the inspection period, since Virginia sellers are not required to volunteer much.

Frequently asked questions

Will my lender require a water test?

Many do, especially for FHA and VA loans. Ask your lender early so the test is done in time.

Should I also test for radon?

Yes. Read Radon Testing in Northern Virginia. Well water can also be tested for radon.

What else should I know about inspections?

See my Home Inspection Guide and Contingencies Explained.