Grand County says it plainly: 'A lender may require that a well be inspected for the purposes of real estate transaction' — testing of the water for coliform bacteria and nitrates plus a visual wellhead inspection. The county doesn't mandate it, but its Environmental Health lab runs coliform/E. coli and nitrate tests with results within 48 hours of drop-off.

County requirement	None — the county frames well inspection and testing at sale as something 'a lender may require': water tested for coliform bacteria and nitrates, plus a visual inspection of the wellhead and surrounding area.
County lab services	Total coliform/E. coli and nitrate testing through the county's own laboratory, results within 48 hours of sample drop-off; fees per the county fee schedule, payable online.
Fuller panels	For testing beyond coliform/nitrate the county forwards samples to the CDPHE lab in Denver for a courier fee. Note (per the county page, checked July 2026): CDPHE chemistry testing has been suspended during an investigation since December 2024 — the county currently accepts coliform and nitrate samples only.
Statewide filing	Every Colorado well sale needs the free DWR change-of-owner filing so the well permit follows the property. source ↗

Details to confirm with the county

We couldn't confirm the following from Grand County's official pages. Check these with the county before you rely on them:

• Exact county lab fee amounts — published in the fee schedule document rather than on the page.

Verified July 2026 · Source: Grand County — Private Well Water