Once your well reaches the productive zone, the driller has to give the water somewhere to enter the casing. There are two main ways to do that: a manufactured screen, or perforations cut into the casing itself.
Perforated casing (the cheaper option)
Perforated casing is just regular well casing with slits or holes cut into it where the producing zone will be. Slot sizes typically range from .060" to .250", depending on the formation. It's the default in coarser formations — gravel, cobbles, fractured rock.
Perforations work great when the water-bearing material is coarse enough not to fall through the slots. Coarse sand, gravel, sand-and-gravel mix, fractured bedrock — all good candidates.
Cost: typically rolled into the per-foot drilling rate. No separate line item.
Stainless wire-wrap screen (the better option for fines)
A wire-wrap screen is a manufactured stainless-steel cylinder with a continuous V-shaped wire wrapped around vertical rods. It gives much higher inflow area than perforations, with very precise slot openings (often .010" to .060") that hold back fine sand and silt.
Screens are needed when the production zone is fine sand, silty sand, or silt — material that would migrate through perforations and either pump sand into the system or collapse the well over time.
Cost: roughly $2,200 for a typical 20-foot section in a 6" domestic well in Utah (2026), installed.
How drillers decide
Two signals:
- Lithology in the production zone. If the layers between static water level and total depth show "fine sand", "silty sand", or "silt", a screen is the safer build. If they show "coarse sand", "gravel", "cobbles", or "rock", perforations are usually fine.
- Neighbor wells. If nearby wells in similar formations went with perforations and they've been pumping clean for years, that's a strong signal you can do the same.
What our calculator does
The Utah Water Well Cost Calculator reads the structured driller logs of nearby wells, identifies the lithology in the likely production zone, and tells you whether a screen is likely needed. If it is, the $2,200 adder is included in the cost estimate so you're not surprised at quote time.
Other completion options
- Open-hole completion — in stable bedrock, sometimes the driller leaves the production zone uncased entirely. Water enters through fractures. Common in granite, limestone, sandstone formations.
- Gravel pack with screen — for very fine formations, a graded gravel pack is placed around the screen to prevent fines migration. Adds about $500–$1,500 to the screen cost.