Well Casing: What It Is and How to Keep It Sound
Well casing lines and protects your well. Learn how it protects water quality and the signs of casing trouble.
Quick Answer
Well casing is the pipe lining the drilled hole that keeps the well open and blocks surface contamination. It typically extends about 12 inches above grade (per local code), with ground sloping away. Cracks, corrosion, or a low casing are contamination pathways; have a licensed contractor repair them.
What the casing does
The casing is the pipe that lines your well from the surface down. It holds the borehole open, keeps loose soil and shallow groundwater out, and works with the grout seal around it to stop surface contaminants from reaching your drinking water. A sound casing is central to a safe, reliable well.
| Condition | Why it matters |
|---|---|
| Casing below grade | Surface water can pool and seep in |
| Cracks or holes | Direct pathway for contaminants |
| Corrosion | Weakens the barrier over time |
| Loose or failed seal at the top | Lets debris and water enter |
Keep the casing proud and the grade sloped
- Inspect the visible casing each year for cracks, rust, and dents.
- Make sure nothing is piled against the casing and the vent stays clear.
- Confirm the ground still slopes away after landscaping or heavy weather.
- Call a licensed contractor if you see damage or suspect a failed seal.
Casing repair and any work below the surface require a licensed well contractor. Do not try to patch or extend casing yourself, because an improper repair can create exactly the contamination pathway you are trying to prevent.
Frequently asked questions
- How high should well casing stick out of the ground?
- It typically extends about 12 inches above grade, but follow your local code. The ground should slope away so water drains away from the wellhead.
Sources & references
- Private Ground Water Wells — CDC, accessed October 29, 2026
- Protect Your Home’s Water: Private Wells — US EPA, accessed October 29, 2026
This guide is documentary research and general information, not a laboratory analysis or professional assessment of your specific well. See our disclaimer.