What Affects Well Drilling Cost

Depth is the primary driver of well drilling cost. Contractors charge per foot drilled, and you pay for every foot whether they find water at 80 feet or 350 feet. There is no way to know the required depth before drilling begins, so the depth on any quote is an estimate. The best free evidence is the well logs of neighboring wells: most states keep a public database of driller logs searchable by address or parcel, showing how deep each well went and where water was found. Ask each driller what depth they are quoting to, what their per-foot rate is, and what happens if they reach that depth without enough water.

The geology underneath your property determines how hard and slow drilling is. Unconsolidated sand and gravel drill fastest but usually need casing to the full depth to stop the hole collapsing. Consolidated rock such as granite or basalt drills slowest and wears bits faster, though the open borehole below the casing often stands on its own. Many drillers quote one rate for overburden (soil, sand, clay) and a higher one for rock, so ask for both and for the depth at which they expect to hit rock. The neighboring well logs show that depth too.

Well drilling requires a large truck-mounted drill rig that needs clear access to the drilling site. If the site has limited road access, the contractor may need to bring smaller equipment or clear a path. Remote rural properties far from the driller's base add travel time. Hillside or sloped properties need the rig leveled. In dense suburban lots, setback rules from septic systems, property lines and structures may leave only one small area where the well can go. Site access is usually quoted as a separate mobilization or access line after the driller has seen the property, so make sure every quote you compare either includes it or names it.

Most states require a well construction permit or a notice of intent before work begins, and some counties add their own. The fee is set by the agency, not the driller, and is published on that agency's fee schedule; drillers usually file the paperwork and pass the fee through. The permit also fixes the required setbacks from septic systems, property lines and contamination sources. After drilling, many jurisdictions require a water quality test from a state-certified laboratory before the well is approved for drinking water. Your state drinking water program lists certified labs, and the lab's own price list is the figure to budget with.

Well casing is the pipe that lines the borehole to prevent collapse and keep surface water out. Residential wells are most often 6-inch casing, in PVC or steel; some jurisdictions or unstable formations require steel. How far the casing goes depends on the geology: through the overburden and seated into rock in a bedrock well, or the full depth plus a screen in a sand-and-gravel well. Some drillers include casing in their per-foot rate and others bill it as its own line, so read quotes carefully before comparing totals. Larger 8-inch and 10-inch casing is used for high-yield irrigation wells rather than household supply.

The pump and water system are separate from the drilling cost but just as necessary. A shallow well (roughly 25 feet or less to water) can use an above-ground jet pump; deeper wells use a submersible pump set inside the casing. The pump is sized to the well yield (gallons per minute) and the depth. On top of the pump, budget for a pressure tank, a well cap and pitless adapter, the trench and water line to the house, and the electrical circuit. Many homeowners get these quoted by both the driller and a local pump installer or plumber.