A water well is any type of excavation created to remove water from an underground aquifer (a geologic formation or series of formations that contain enough water to supply wells and springs). Wells created using traditional digging methods (pick and shovel or backhoe) are typically wide holes only 10'-30' deep. Driven wells are created by driving a small diameter pipe into soft earth (gravel or sand) and are generally 30'-50' deep.
The most common method of well construction in the United States today is drilling, which requires a fairly complicated and expensive drill rig, usually mounted on a large truck. Drilled wells are typically 100'-400' deep but can be 1,000' or more. The U.S. Geological Survey provides an overview of types of wells and the Environmental Protections Agency provides some more water well-related information.
- Prices for drilling a water well are typically quoted by the foot, and vary significantly depending on the type and difficulty of the material being drilled through (sand, solid rock, clay, etc.).
- Drilling the well hole, installing the casing (a tubular lining that prevents the well hole from collapsing) and adding a well cap (a tight-fitting, vermin-proof top seal) typically costs $15-$30 per foot, or $1,500-$3,000 for a 100' deep well, and $6,000-$12,000 for a 400' well. (However, if the geological conditions are especially difficult or access is extremely limited, drilling can cost $30-$50 a foot or more.) For example, the sustainable Arizona homesteaders at ByExample.com report paying $6,750 to have well drilled 280' deep, or about $24/foot.
- A complete water system is typically designed (and a total price quoted) after the well is successfully drilled and the well's depth and water yield is known. A well pump to bring the water to the surface, a pressurized storage tank or tanks (if the well's yield is not enough to meet peak demand), underground piping to take the water to the house, electrical wiring to power the system, a control panel and other items can add $2,000-$8,000 or more to the total cost, depending on the size of pump and the distance to the house.
- This brings the typical total for drilling a well and setting up a private water delivery system to $3,500-$20,000 or more, but an especially deep and difficult well with a complex water system can cost $20,000-$50,000 or more, depending on depth, water yield and system complexity.
- A great deal depends on local geological conditions. For example, Cushing & Sons Well Drilling in New Hampshire estimates an average cost of $5,000 for a complete water well system in that area, while a Colorado landowner reports costs of $14,000 to drill a 600' well (about $23-$24/foot) and another $7,000-$8,000 for a constant pressure pump system with a 70' water line to the house, or $21,000-$22,000 total.