Who actually requires a well test when you sell a Colorado home

Last reviewed: July 9, 2026

Ask three people whether Colorado requires a well water test when you sell a house and you’ll get three answers. The county says one thing, the buyer’s lender says another, and the internet says both. Here’s the actual structure, with sources — because the honest answer is: it depends on three separate layers, and each one is checkable.

Layer 1: Your county (usually no — with real exceptions)

Colorado has no statewide law requiring a private well test at property transfer. Counties set their own rules, and most set none for wells. El Paso County’s public health lab says it as plainly as anyone: “In a real estate transaction it is the lender who determines what testing is required.”

But “usually no” is not “always no”:

• Jefferson County requires a well water sample (total coliform and nitrate) before it will issue a construction, repair, or Use (transfer of title) septic permit in the Indian Hills/Parmalee Gulch area — and has a separate raw-water testing rule for parcels created before June 3, 1966.
• Pueblo County carries a $25 bacteriological water test on its septic Transfer of Title fee schedule, charged “when required” — the water test rides the septic program.
• Several mountain counties (Grand, Summit) don’t mandate testing but run their own labs and spell out what lenders typically ask for.

The pattern to notice: where county well testing exists, it usually rides the septic transfer program. If your sale triggers a septic transfer-of-title inspection, that’s the moment a water-test rider can appear. (Selling with a septic system too? Our sister site covers every county’s septic transfer rules at septictransfer.com.)

Layer 2: The buyer’s lender (the usual driver)

When a well test happens at a Colorado closing, it’s most often because the buyer’s financing requires it:

• FHA requires well testing only in specific cases — when the appraiser can’t confirm the property meets HUD’s minimum property requirements, or something in the file flags the well. It is not automatic on every FHA loan, despite what listing-side lore says.
• VA loans need evidence the water is safe and the well produces adequately; USDA rural loans have similar water-quality evidence rules.
• Even conventional buyers’ underwriters sometimes ask, especially when an appraisal notes a well in poor repair.

The full breakdown — including HUD’s well-to-septic distance standards and who’s allowed to pull the sample — is in our FHA and VA well requirements guide.

Layer 3: The state filing everyone forgets (always yes)

Whatever happens with testing, every Colorado well sale needs one piece of state paperwork: the Division of Water Resources change-of-owner filing, which updates the well permit to the new owner. It’s free, it’s quick, and title companies file it “in many cases” — which means sometimes nobody does, and the permit quietly stays in the old owner’s name. The well permit transfer guide walks through the forms and how to check whether yours was ever filed.

So what should a seller actually do?

1. Check your county’s page on this site — it tells you whether any county requirement exists, where the nearest lab is, and what it costs where the county publishes it.
2. Ask the buyer’s agent what loan the buyer is using. FHA/VA/USDA means plan for a water test; get it scheduled early, because labs take days and a failed bacteria test takes longer to fix than most closing extensions.
3. Confirm the DWR filing at closing — or file it yourself in ten minutes.

If you’d rather hand the sampling and paperwork to someone who does this weekly, that’s what the form below is for: it goes to a local well professional serving your county, not a call center.