Well drilling and maintenance

Well drilling gives you permanent, independent access to groundwater — the only water source on a homestead that does not depend on rain, rivers, or the municipal grid. The difference between a well that serves you for decades and one that fails in year three comes down to three decisions made before a single foot of hole is drilled: choosing the right drilling method for your geology, selecting casing and pump components sized for your depth, and committing to a maintenance schedule that catches problems before they become failures.

This page covers all three decisions in enough detail to let you work intelligently with a licensed driller, evaluate bids, specify equipment, and maintain the system yourself. For hand pump selection and installation alongside a submersible pump, see Wells — Drilling, Digging, and Hand Pumps, which also covers the Bison Pump, Simple Pump, and Flojak options in detail.

Choosing a drilling method

The geology under your property determines which method is practical. Using the wrong technique wastes money — and in some cases simply will not work.

Rotary drilling

Direct mud rotary is the dominant method for residential drilled wells. A rotating drill bit cuts through soil and rock while circulating drilling fluid (water and bentonite clay) carries cuttings to the surface and stabilizes the borehole walls. Practical depths range from 50 to 1,000+ feet (15–305 m) with no geological upper limit.

Best for: Consolidated formations — fractured rock, shale, limestone, granite
Typical production rate: 5–15 feet (1.5–4.6 m) per hour in soft rock; 1–3 feet (0.3–0.9 m) per hour in hard granite
Requires: Licensed contractor with a rotary rig (typically a diesel truck-mounted unit)
Cost tier: Moderate to significant investment depending on depth; approximately $25–$65 per foot ($82–$213 per m) for drilling alone, rising to $60–$100 per foot ($197–$328 per m) in hard granite formations

Air rotary replaces drilling fluid with compressed air. It drills faster in hard, stable rock and avoids contaminating the formation with drilling mud — which matters for yield and water quality. Air rotary is standard in the southeastern and northeastern U.S. where crystalline bedrock is common.

Drilling fluid and your aquifer

Bentonite clay in mud rotary drilling fluid can seal fractures and reduce initial well yield. A thorough well development step (pumping at high rate until water runs clear) is essential after mud rotary drilling. If your contractor doesn't include well development in the bid, add it — or specify air rotary to avoid the issue entirely.

Cable-tool (percussion) drilling

An older method that drives a heavy chisel-like bit into the formation with a rhythmic up-and-down action. Slower than rotary (2–10 feet / 0.6–3 m per day) but gentler on the formation. Still the preferred method in areas with cobblestones, boulders, or unstable gravel layers that collapse around a rotary bit.

Best for: Unconsolidated formations with boulders; soft rock alternating with hard zones
Depth capability: Effectively unlimited; many cable-tool wells exceed 500 feet (152 m)
Advantage: Better formation development; less risk of formation damage; drillers can still find and adjust to formation changes in real time
Cost tier: Moderate investment; slower means higher day-rate costs, but can be cheaper than rotary in challenging geology

Driven point wells

A perforated steel tip (the "drive point" or "sand point") is driven into the ground by hammering, pulling shallow groundwater from sandy or gravelly unconsolidated formations. No drilling rig required.

Join 1.25-inch (3.2 cm) or 2-inch (5 cm) galvanized steel pipe in 4-foot (1.2 m) sections using threaded couplings.
Attach the drive point — a pointed, screen-slotted steel tip — to the bottom section.
Drive the assembly downward using a post driver, slide hammer, or fence post weight. Do not strike directly on the pipe threads.
Add sections as you descend. Drive until the point is at least 5 feet (1.5 m) below the water table, confirmed by water rising in the pipe.
Install a pitcher pump or suction jet pump at the surface.

Hard limits: Maximum practical depth is 25–30 feet (7.6–9 m). Usable only in sand and gravel — dense clay or rock stops a drive point immediately. Contamination risk is high because the aquifer is shallow. Test the water before drinking and at least every six months thereafter.

Field note

Before hiring a driller, pull the county well completion reports for properties within a half-mile (0.8 km) of your site. Most state geological surveys post these online. Look for the static water level (depth to water when pump is off) and total well depth. Those two numbers bracket your likely drilling cost — and tell you whether a submersible or jet pump is appropriate before you ever call a contractor.

Bored and augered wells

A mechanical auger bores a large-diameter hole (18–48 inches / 46–122 cm) in unconsolidated soil to shallow depths, typically 20–50 feet (6–15 m). The large diameter provides substantial storage volume inside the casing. Hand augering is limited to about 30–40 feet (9–12 m) in soft soil. Machine boring reaches 50–100 feet (15–30 m) in the right conditions.

Best for: Areas with high water tables in clay or mixed soils, where a large storage volume compensates for modest yield
Not suitable for: Bedrock, consolidated rock, or sites deeper than 50 feet (15 m)
Cost tier: Affordable to moderate investment, much less than rotary drilled wells

Casing: materials, dimensions, and depth ratings

The casing keeps the borehole from collapsing and blocks surface contamination from entering the well.

PVC Schedule 40 vs. Schedule 80

Schedule 40 PVC has a wall thickness of approximately 0.109 inches (2.8 mm) for 4-inch pipe. It is adequate for wells shallower than 100 feet (30 m) in stable, non-caving formations. Its lower cost makes it the default for shallow residential wells, but its yield strength is roughly one-fifth that of steel.

Schedule 80 PVC has a wall thickness of approximately 0.154 inches (3.9 mm) — 41% thicker. Use it for wells deeper than 100 feet (30 m), formations with collapse risk, or anywhere the pipe must resist lateral soil pressure during installation. Schedule 80 is the current best practice recommendation for residential drilled wells in most states.

Both grades are NSF/ANSI 61 certified for drinking water contact and resist corrosion indefinitely. PVC does not leach into water under normal groundwater conditions.

Steel casing

Galvanized or black steel was the residential standard before PVC became widely available. It provides crush strength that PVC cannot match — useful in deep wells in unstable formations or where heavy equipment loads are expected at the surface. The downside: steel corrodes in acidic groundwater (pH below 6.5) or water high in dissolved oxygen, chlorides, or sulfates. Corrosion products (iron, manganese) enter the water and eventually compromise well integrity. Modern installations typically use steel only for the surface casing — the outer sleeve covering the top 20 feet (6 m) — then transition to Schedule 80 PVC below.

Stainless steel (304 or 316 grade) resists corrosion in virtually all groundwater environments. Type 316 adds molybdenum for extra resistance to chloride-heavy water. Stainless is the specification for municipal production wells and is worth considering for deep residential wells in aggressive groundwater chemistry. The cost is a significant investment compared to PVC, but stainless casing can outlast the property deed.

Surface casing and grouting

Regardless of primary casing material, the top 20 feet (6 m) of every drilled well requires:

Steel surface casing installed concentric with the primary casing, creating an annular space between them.
Neat cement grout pumped into the annular space under pressure, from the bottom up. Grout seals the path that surface runoff, soil bacteria, and agricultural chemicals could otherwise travel down to reach the aquifer.
The casing must extend at least 12 inches (30 cm) above finished grade so that surface water drains away from the wellhead.

Most states mandate this grouting procedure by regulation. A contractor who skips it is cutting a corner that will eventually contaminate your water.

Pump selection: depth, flow, and power

Match the pump type to well depth first, then to your flow requirement.

Submersible pumps

A submersible pump sits submerged in the water at the bottom of the well and pushes water up through the drop pipe to the surface. It is the standard pump for residential drilled wells deeper than 25 feet (7.6 m).

Depth range: 25–400+ feet (7.6–122+ m)
Flow rates: 3–20 GPM (11–76 L/min) depending on pump model and well yield
Power draw: 500–1,500 watts (0.5–1.5 kW) for residential 1/2 to 1.5 HP pumps
Sizing rule: Select a pump flow rate no higher than the well's tested yield. A 2 GPM (7.6 L/min) well paired with a 10 GPM (38 L/min) pump will pump the well dry and damage the pump. Always ask the driller for the completed well's pump test results before purchasing a pump.
Power vulnerability: A submersible pump is useless without electricity. For off-grid resilience, pair it with a solar-powered pressure system or install a hand pump alongside it.

Jet pumps

A jet pump sits at the surface and creates suction to pull water up the drop pipe. Available in two configurations:

Shallow-well jet pump: Uses a single drop pipe and ejector at the pump itself. Maximum practical lift is 25 feet (7.6 m) — physics limits suction-based lift regardless of pump horsepower.

Deep-well jet pump: Uses two pipes — a pressure pipe and a return pipe — with the ejector set downhole. Extends usable depth to about 110 feet (33.5 m). Less efficient than a submersible at comparable depths; power draw is typically 800–2,000 watts.

Jet pumps are easier to service because the mechanical components are at the surface. They are a reasonable choice for shallow wells (under 80 feet / 24 m) where serviceability outweighs efficiency.

Hand pumps for grid-down operation

A hand pump provides mechanical water access with no electricity dependency. The critical depth threshold is 25 feet (7.6 m): above that, a suction-type pitcher pump or cast-iron farm pump works. Below that, you need a force pump with the cylinder set below the water table.

For deep wells, the Bison Pump and Simple Pump (both rated to 350 feet / 107 m) can be installed alongside an existing submersible pump in a dual-pipe configuration. See Wells — Drilling, Digging, and Hand Pumps for detailed specifications and installation guidance on both.

Field note

The cylinder depth determines hand pump effort. A pump set 200 feet (61 m) down requires significant arm force per stroke. Before installing a deep hand pump, ask the supplier to specify the pounds of force required per stroke at your depth — and test it yourself if possible. A pump that only a strong adult can operate is not a family water supply.

Static water level and seasonal monitoring

The static water level is the depth to the water surface in your well when no pumping is occurring. Your driller's completion report lists this measured immediately after drilling. It is your baseline.

Track it annually. A rising static level over years suggests improved aquifer recharge. A falling level signals either aquifer depletion (drought, over-pumping by neighboring wells) or a mechanical problem with your well.

How to measure static water level without a meter:

Lower a weighted string into the well casing until you feel the weight stop. Mark the string at the top of the casing.
Raise the string and measure from the mark to the wet portion. The length of dry string above water is your static water level.
Record the date, recent weather (drought or wet season), and any changes in pump behavior.

For continuous monitoring, a well sounder (a battery-powered electronic meter with a probe on a calibrated cable) gives accurate readings in minutes — an affordable tool for any property owner who runs their own water system.

Drawdown is how far the water level drops during active pumping. A normal drilled well recovers to static level within 30–60 minutes after pumping stops. If recovery slows noticeably over a season, something is changing — either the aquifer is stressed or the well screen is plugging.

Seasonal maintenance schedule

A private well requires no licensed contractor for most routine tasks. The following schedule keeps problems small.

Annual tasks (spring, after frost)

Visual inspection: Walk the wellhead. The well cap must fit snugly with no cracks. Check that the casing still extends at least 12 inches (30 cm) above grade — frost heave can shift it. Confirm that the ground still slopes away from the casing.
Well cap seal: Replace the cap if the foam gasket is cracked or if anything could have bypassed the seal (a cap that was left loose, vermin damage, flooding).
Shock chlorination: Disinfect the well once per year regardless of test results (see procedure below).
Water test: Submit a sample to a certified state lab for total coliform, E. coli, and nitrates at minimum. Many county health departments offer free or low-cost testing.
Pump inspection: Listen for unusual sounds during pump operation (grinding, cycling too rapidly). Check pressure tank pre-charge (should be 2 PSI below pump cut-in pressure, typically 28 PSI for a 30/50 switch). A waterlogged pressure tank short-cycles the pump and burns it out prematurely.

Every 3–5 years

Full water chemistry panel: arsenic, lead, iron, manganese, hardness, pH, sulfates, and any contaminants specific to your region (check your state's agricultural extension service for local priorities)
Measure static water level and compare to your baseline
Inspect pitless adapter for leaks (the underground fitting that directs water from the casing to the horizontal line heading to your home)

After any of these events

Event	Immediate action
Flooding within 50 feet (15 m) of wellhead	Do not use; shock-chlorinate; retest before resuming
Nearby chemical spill or tank failure	Test for VOCs, petroleum, and relevant compounds
Well repair or pump replacement	Shock-chlorinate before returning to service
Extended non-use (6+ months)	Flush until water runs clear; test bacteria
Muddy or turbid water after heavy rain	Check well cap integrity; test for coliform

Shock chlorination procedure

Shock chlorination disinfects the well and distribution plumbing using concentrated chlorine solution. Do this annually and after any contamination event.

What you need: Unscented household bleach (5.25–8.25% sodium hypochlorite), a clean bucket, a garden hose, and pool test strips.

Calculate the well water volume. Multiply the casing diameter area by the water column height.
For a 6-inch (15 cm) diameter casing: area = 0.196 sq ft (0.018 m²)
Water column = total well depth minus static water level
Example: 300-foot (91 m) well, static water at 80 feet (24 m) = 220 feet (67 m) of water column × 0.196 = 43 gallons (163 L) in the casing
Mix the chlorine dose: 1 quart (946 mL) of 5.25% bleach per 100 gallons (378 L) of water in the well. For the example above: approximately 0.43 quarts (407 mL). Round up.
Pour the chlorine solution into the well. Use a clean funnel through the well cap port, or temporarily remove the cap.
Circulate. Run a hose from an outdoor spigot back into the top of the casing and recirculate water for 15–20 minutes. This mixes the chlorine throughout the water column and ensures it contacts the casing walls.
Run every fixture. Open every faucet, shower, and toilet until you smell chlorine — this charges the entire distribution system with treated water.
Wait 12–24 hours. Do not use any water during this period.
Flush thoroughly. Run water until chlorine odor is gone. Use pool test strips to confirm chlorine level drops below 1 ppm before resuming normal use. Discharge this flush water away from wells, septic systems, and water features — high chlorine concentrations kill septic bacteria.
Retest. Submit a bacteria sample 5–7 days after flushing. Do not consider the well safe until you receive a clear result. For detailed water testing protocols, see Water Testing.

Chlorine and your plumbing

Shock chlorination at the concentrations used for well disinfection (50–200 ppm) will temporarily discolor water and may cause rubber gaskets or old iron fittings to degrade if left in contact for more than 48 hours. Flush completely within 24 hours of introduction. If you have rubber-seated pressure-reducing valves or older well system components, isolate them during the treatment period.

Well rehabilitation

When a well's yield declines significantly from its original production — typically more than 30% — the cause is usually one of three things: mechanical plugging, mineral fouling, or aquifer depletion. Each has a different fix.

Diagnosing yield loss

Before calling a rehabilitation contractor, run a simple pump test yourself:

Note the static water level (depth to water when pump is off).
Run the pump at normal household demand for one hour.
Measure the water level after the hour. If it has dropped more than 30–40 feet (9–12 m) from static, your yield is reduced from the well's original capacity.
Turn the pump off and time recovery back to static level. Longer-than-normal recovery confirms reduced yield.

Surging

Surging uses alternating pressure waves to dislodge clay particles, silt, and biofouling from the well screen and the formation immediately surrounding it. A licensed driller runs a surge block (a close-fitting plunger-like device on the drill string) up and down through the water column, forcing water in and out of the screened interval. The loosened debris is then bailed or pumped out.

Surging is the least aggressive rehabilitation method and the first one to try. It costs an affordable to moderate rate for a contractor visit and successfully restores yield in many cases where the well screen has gradually plugged with fine sediment.

Acidization

For wells with mineral scaling (iron deposits, calcium carbonate, manganese oxide), acid treatment dissolves the scale from the casing perforations and the surrounding formation. The standard acid is a glycolic-acid or hydrochloric-acid solution, introduced into the well and allowed to react for a specified soak period before being pumped out and flushed. Neutralization and proper disposal of the spent acid are required.

This method is most effective in limestone aquifers where carbonate scaling is common, and in any well with heavy iron biofouling (the orange-brown slime deposit often visible on fixtures). Wells treated with acid frequently recover to 70–90% of their original capacity.

Hydrofracturing

Hydrofracturing (also called hydrofracking — not to be confused with oil/gas hydraulic fracturing) applies high-pressure water directly to the rock formation in bedrock wells to open existing fractures and create new pathways for groundwater. A specialized packer system isolates the target zone in the well; water is then injected at pressures of 500–1,500 PSI (34–103 bar).

Hydrofracturing is specifically for bedrock drilled wells in consolidated rock. It does not work in sand, gravel, or unconsolidated formations. Success rates are 70–90% for appropriate candidates, with typical yield increases of two to ten times original production.

The procedure requires a licensed contractor with specialized equipment. It is a moderate to significant investment but costs far less than drilling a new well. If your drilled well is in granite, schist, or limestone and its yield has declined substantially, get a hydrofracturing quote before abandoning the well.

Field note

When your well yield drops, the cheapest question you can ask is: have your neighbors noticed the same thing? If two or three wells in your area are all declining at the same time, the aquifer is stressed — likely from drought or increased regional pumping. No amount of rehabilitation fixes an aquifer that isn't recharging. The right response there is storage capacity: a cistern sized for drought conditions, fed by the well during wet periods.

Permitting and legal requirements

Well drilling is regulated in all 50 U.S. states. Permit requirements, setback distances, and construction standards vary but share a common framework:

Permit before drilling: Required in virtually every jurisdiction. Fees range from inexpensive to affordable depending on state.
Licensed driller: Virtually all states require a licensed contractor; DIY rotary or cable-tool drilling is illegal in most jurisdictions.
Setbacks: Minimum separation from septic systems (typically 50–100 feet / 15–30 m), fuel storage, animal waste areas, and property lines.
Completion report: The driller files a well completion report with the state detailing depth, geology, casing specifications, and pump test results. Request a copy — it is your baseline document for every future maintenance decision.

Contact your state's Department of Natural Resources, Health Department, or Water Resources agency for current requirements. The NGWA (National Ground Water Association) also maintains a state-by-state regulatory directory.

Well drilling and maintenance checklist

With your well producing reliable water, the next priority is ensuring you can use it when the grid is down. A solar-powered pump controller or a properly installed hand pump means the water keeps flowing regardless of power availability — see the Energy foundation for sizing a solar system around your pump's wattage requirements.