Here's what a standard home inspection says about a private well: the pump turned on, water came out. That's roughly it. The inspector isn't a well contractor, doesn't test the water beyond maybe a courtesy bacteria sample, and won't tell you that the "excellent well!" in the listing is a 40-year-old, 2-gallon-per-minute marginal producer with a pump on borrowed time and arsenic in the aquifer.
Everything about the well is knowable before closing — and every item on this list is negotiating leverage. A failing well system is a $5,000–$25,000 problem. Here are the twelve points, in the order a pro would check them.
The Paper Trail (Points 1–3)
1. The well log (drilling report). The well's birth certificate: depth, casing, static water level, and the driller's yield test (gallons per minute) on completion day. Most states keep these in a searchable online database — find it yourself in ten minutes; don't rely on the seller's memory. No log anywhere? Price in uncertainty.
2. Age of everything. Well age (drilled wells live 30–50+ years, but components don't), pump install date (10–15 year lifespan — the failure signs), pressure tank age (7–15 years). A 13-year-old pump isn't a dealbreaker; it's a line item in your negotiation.
3. The service history — or the absence of one. Ask for maintenance records, past water tests, shock chlorination dates, repairs. Most sellers have nothing, which tells you two things: budget for deferred maintenance, and notice how valuable the records you keep will be when you sell someday.
The Water (Points 4–6)
4. The full laboratory panel — paid for by you, sampled by you (or your inspector), never seller-supplied. This is the one place not to economize. The Tap Score Full Panel Well Test covers the FHA/VA-style essentials — bacteria, nitrates, lead, arsenic — plus the metals, minerals, and chemistry that reveal what treatment the house actually needs. (FHA/VA/USDA loans require a water test; conventional loans don't, which is exactly why you should.)
5. Read results against the house's equipment. Softener present? Then hardness is high — is the softener working and staying? UV system? Then the well has a bacteria history — when was the bulb changed? Treatment equipment is a confession of the water's problems; make sure the confession and the lab report agree.
6. Location and setbacks. Wellhead distance from the septic tank and drain field (most codes: 50–100 feet), from livestock areas, fuel tanks, and the road (salt). Downhill from any of these is worse than the same distance uphill.
The System (Points 7–10)
7. A real flow/yield test — the sputter test scaled up. Have your inspector (or a well contractor, ~$150–$400 for a proper well inspection — worth it on any well older than 15 years) run water at a steady clip for 30–60 minutes while watching pressure and recovery. A well that delivers 5 GPM for an hour is healthy; one that fades in 20 minutes is a low-yield well wearing makeup. The seller running the dishwasher before your visit doesn't count as a test.
8. Wellhead condition. Casing 12+ inches above grade, intact vermin-proof cap (a $40 fix — but a cracked cap plus a clean bacteria test means the test got lucky), ground sloping away, no well pit (pits are code violations in most states now and a red flag for both flooding and freezing).
9. Pressure system behavior. Watch a full pump cycle: smooth climb to cut-out, no short cycling, no chattering switch, tank air charge correct. Five minutes at the pressure tank tells you more than an hour of tap-running.
10. The electrical. Wiring condition at the switch and control box, a dedicated breaker, and — bonus points — an amp reading on the pump against its nameplate. High amps = a pump working too hard = your first year's surprise expense.
The Context (Points 11–12)
11. The neighborhood aquifer. Ask neighbors (they'll tell you): anyone's well gone dry? Deepened recently? New irrigation or development drawing on the same water? County water departments and state geological surveys publish groundwater trends for many areas.
12. The escrow math. Total the findings: pump age past 10 years (–$1,500 future), no records (–uncertainty), hardness needing a softener (–$1,000), arsenic needing treatment (–$500–$2,000), marginal yield (–$3,000+ for storage). These are normal negotiation items — if you know before closing.
Your Action Plan
- Before the offer: pull the well log from the state database; eyeball the wellhead and setbacks.
- In your inspection contingency: independent water test (full panel) + well system inspection with yield test. Both, explicitly, in writing.
- Negotiate with the findings like any roof or furnace issue.
- Day one as owner: shock chlorinate (you don't know what's down there — here's how), replace filter cartridges, and start the service history the last owner never kept.
And that last point is where the WellKept app enters on move-in day: log the well's vitals from the well log (depth, yield, static level), the lab results, the equipment ages you learned during inspection — and from then on, every filter change, test, and repair. You inherited a well with no history. The next owner of this house won't — and until then, you'll be the rare well owner who knows exactly what's underground, what it tested at, and what's due next. Download it free the week you get the keys.
Frequently Asked Questions
What should I test well water for when buying a house? At minimum the FHA-style panel: total coliform bacteria, E. coli, nitrates, lead, and arsenic. A full panel adds iron, manganese, hardness, pH, sodium, and regional risks (radon, uranium, VOCs, PFAS). Always use an independent lab test you sample yourself — never rely on a seller-provided result.
Who pays for a well inspection when buying a home? Typically the buyer, as part of the inspection contingency — $150–$400 for a dedicated well inspection with a yield test, plus $150–$300 for a comprehensive lab panel. Both are negotiating instruments: documented deficiencies routinely return many times that cost in credits or repairs.
What is a good well yield for a house? 5+ gallons per minute sustained is comfortable for a typical family; 3–5 GPM is workable; under 3 GPM is low-yield and deserves either a price adjustment or a storage-tank plan. The number must come from a sustained 30–60 minute test, not a quick faucet check — marginal wells pass short tests.
Should I shock chlorinate a well after buying a house? Yes — it's cheap insurance against whatever the previous owner's maintenance habits left behind, and the right moment to inspect the wellhead, replace filter cartridges, and establish your baseline water test. Do it in the first month, then retest bacteria two weeks later.
Can you get a mortgage on a house with a well? Yes — wells are routine for lenders. FHA, VA, and USDA loans require a passing water test (bacteria, nitrate, and often lead) and minimum setback distances from septic systems; conventional loans usually don't require testing, which shifts the burden of due diligence entirely onto you.