Buying a house with a well and a septic system: a checklist

A house with a private well and a septic system comes with its own water supply and its own wastewater treatment. Nobody else tests the water or maintains the tank: after closing, that is your job. The inspections on this page are how you find out what you are taking on while you can still negotiate.

Rules differ a lot by state and county, so treat this as a checklist to adapt, and call the county health department early.

The checklist

Step	Who does it
Ask the seller for well records, water tests and treatment equipment details	You or your agent
Ask for septic records: permit drawing, pumping and repair receipts	You or your agent
Check what the county or state requires at sale	County health department
Ask your lender what it requires	You
Test the water at a certified lab	You or your inspector
Have the well inspected	Licensed well contractor
Have the septic system inspected	Septic service provider
Find any unused wells on the property	Seller, well contractor

Built from EPA's homebuyer guide to septic systems and the homebuyer guides of Minnesota's Department of Health, Iowa's State Hygienic Laboratory and Oregon State University.

1. Collect the records

For the well, Iowa’s state laboratory suggests asking for construction logs and the well’s type, age, depth, capacity and yield, plus any water quality and maintenance records: repairs, shock chlorination and the age of the pump³. Minnesota’s Department of Health suggests asking the seller²:

• When was the water last tested, and what for?
• Are there any water treatment systems in place?
• Have there been water quality issues in the past?
• Are there any well records available?

If there is treatment equipment, such as a softener, filter or reverse osmosis unit, find out why it was installed, whether it works and whether there are maintenance records. Poorly maintained equipment can affect water quality³.

For the septic system, ask for the “as built” drawing, which you can also request from the local health department, and for pumping and maintenance records¹. The county office that issues septic permits can provide a map of the system and tell you what type it is⁴. Find out whether it has pumps, filters or special treatment, and what that kind of system costs to maintain⁴.

2. Check what the law and your lender require

There is no single national rule. Three examples show how much it varies:

• Oregon requires the well water to be tested for bacteria and nitrate at sale and the results reported to the state. The tests don’t have to pass⁴.
• Minnesota requires sellers to disclose every known well on the property and whether it is in use. The state doesn’t require a water test at sale, but some counties do, and many property transfers require a compliance inspection report for the septic system².
• Lenders can add their own conditions⁴. Iowa’s state laboratory tells buyers using FHA or VA loans that they must have the water tested for total coliform and E. coli, lead, nitrate and nitrite³. EPA notes that a septic inspection may be required by local or state government or by your mortgage lender¹.

Ask the county health department and your lender what applies to you before you set your inspection deadlines.

3. Test the water early

Iowa’s state laboratory advises testing as part of the home inspection and sending samples to the lab as soon as possible, so results don’t delay the closing³.

What to test for:

• The yearly basics. EPA recommends testing private wells for total coliform bacteria, nitrates, total dissolved solids and pH⁵.
• Once for the property. Minnesota recommends testing at least once for arsenic, lead and manganese, in addition to coliform bacteria and nitrate, and says testing is even more important if young children will drink the water².
• Local problems. Your health department can tell you which other contaminants are common in the area’s groundwater⁵.

Use a laboratory certified for drinking water testing⁵. Our well water testing guide covers how to find one, how to take the sample and what the results mean, and the planner below builds a test list for your situation.

Well water test planner Tick what applies to your home and get the tests public health agencies suggest, and why.

A bad result is not automatically a reason to walk away. Minnesota points out that there may be cost-effective ways to remove or reduce a contaminant², and our guide explains what to do after a positive coliform test. It is, however, a reason to get a quote for the fix before you agree on the price.

4. Have the well inspected

Minnesota warns that wells are not typically looked at as part of a home inspection, and suggests asking your inspector to check for obvious problems such as cracks, or contacting a licensed well contractor². Iowa goes further: a certified well contractor should inspect the condition of the well, confirm it meets regulations and address any problems³.

Things you can look at yourself on a first visit:

• The cap and casing. Minnesota describes a newer well as having a weather-proof cap, 12 inches of casing above the ground and a tag with a unique well number². EPA lists a cracked, corroded or damaged casing and a broken or missing cap among the things to watch for⁵.
• The ground around it. It should slope away from the well so runoff drains away⁵.
• What is nearby. Penn State recommends keeping the area within 100 feet of a well free of pollution sources⁶. Note where the septic tank and drain field are in relation to the well.
• Old or unusual wells. Older wells may be dug or buried and lack these features. If you can’t find the well, Minnesota says to contact a licensed well contractor².

Ask about unused wells too. Minnesota’s advice to sellers is to seal any unused wells on the property².

5. Have the septic system inspected

EPA’s advice is direct: have the system inspected by a septic system service provider before you buy¹. According to EPA, the inspector should check¹:

• Pumping and maintenance records
• The age of the system
• Sludge and scum levels in the tank
• Signs of leakage, such as low water levels in the tank
• Signs of backup, such as staining in the tank above the outlet pipe
• The condition of the tank and the inlet and outlet pipes
• The drain field, for signs of failure such as standing water
• The distribution box, to see that the drain lines receive equal flow
• Available records, to confirm the system complies with local rules on function and location

Oregon State University’s well water program adds practical advice: have the tank pumped, and while it is empty ask the pumper to check the inlet and outlet baffles and look for cracks or holes⁴. Look at the drain field as well. Wet ground, odors or very lush growth can signal a problem⁴, and EPA lists a strong odor and bright green, spongy grass over the drain field among the signs of a malfunction¹.

What it can cost if something is wrong

• Routine septic service. EPA’s guide says an inspection with pumping as needed typically costs $250 to $500, based on nationwide industry estimates from 2017¹. Our guide to how often to pump a septic tank has more recent pumping prices.
• Septic repair or replacement. EPA says this can cost thousands to tens of thousands of dollars¹. Oregon State puts a new drain field at $5,000 to $10,000 or more⁴.

County septic officials can explain the likely repair costs in your area⁴. If an inspection finds a problem, get a written quote from a local contractor and use it in the negotiation.

After you move in

• Test the water every year⁵, and keep the results with the well records.
• Have the septic system inspected every three to five years and pumped when the inspection says so¹. Our septic pumping calculator estimates the interval for your tank and household.
• Keep a file: the well log, water test results, inspection reports, contractor invoices and equipment manuals⁶. The next buyer will ask you for it.