Restoring an old water well is possible in many cases, but the process starts with figuring out whether the well is worth saving. A professional inspection, including a downhole camera survey, reveals the condition of the casing, screen, and surrounding formation. From there, restoration typically involves cleaning out accumulated sediment and mineral buildup, repairing or lining damaged casing, disinfecting the well, installing a new pump, and testing the water. Most residential well rehabilitations cost between $2,000 and $10,000 or more, depending on the well’s depth, condition, and what needs to be replaced.
Evaluating Whether the Well Can Be Saved
Before spending money on rehabilitation, you need to know what you’re working with. A licensed well contractor can run a downhole camera through the well to inspect the casing for cracks, corrosion holes, and collapse. They’ll also check whether the well is straight enough to accept a pump and whether the screen (the slotted section at the bottom that lets water in) is still intact. If the casing has collapsed entirely or the well has shifted so far out of alignment that equipment can’t pass through, restoration may not be practical.
The well’s yield matters too. A contractor can measure the static water level (how high the water sits when nothing is pumping) and perform a basic pump test to see how many gallons per minute the well produces. If the aquifer has dropped significantly since the well was originally drilled, even a perfect rehabilitation won’t give you enough water. For a typical household, you’ll need roughly one gallon per minute for each fixture in the home, including faucets, toilets, showers, and water-using appliances like dishwashers and washing machines. A house with two bathrooms, a kitchen, a washing machine, and an outdoor spigot might need 10 to 12 gallons per minute.
State regulations vary, but most require that any structural work on a well be done by a licensed water well contractor. In Tennessee, for example, anyone who constructs, reconstructs, or repairs a water well must follow the state’s Wells Act, and the driller must file a completion report within 60 days. Some states require a Notice of Intent before work begins. Check with your local health department or state water resources agency for the rules where you live.
Cleaning Out Sediment and Mineral Buildup
Years of sitting idle allow sediment, silt, iron deposits, and biological slime to accumulate inside the well casing and clog the well screen. This buildup chokes off the flow of water from the surrounding aquifer. Cleaning it out is usually the first and most impactful step in restoration.
Physical cleaning methods include wire brushing (using a stiff brush lowered on a drill rig), surging, high-pressure jetting, and hydrofracturing. Surging uses a plunger or compressed air to force water back and forth through the screen, loosening debris. High-velocity jetting, where water is blasted through a rotating nozzle lowered into the well, is generally considered the most effective approach. When the well’s own water is recirculated for jetting, removing the dislodged sediment before reuse allows the cleaning solution to penetrate deeper into the formation and produce better results.
For heavy mineral scale, chemical treatment may be necessary. A contractor may use muriatic acid (an industrial-grade hydrochloric acid solution at about 30 percent concentration) to dissolve calcium and mineral encrustation on the screen, casing, and gravel pack. Phosphoric acid is a milder option that works on iron and manganese deposits but is less effective against biological buildup. Glycolic acid targets biological accumulations specifically. These acids are pumped into the well, allowed to react with the deposits, then pumped back out. Your contractor will handle the neutralization and disposal, which is important because improper discharge of acid or phosphorus-containing solutions can harm nearby water bodies.
Repairing or Lining Damaged Casing
If the camera inspection reveals cracks, corrosion holes, or deteriorated joints in the casing, water from shallow soil layers or surface runoff can leak into the well and contaminate your supply. The fix is usually installing a liner: a smaller-diameter casing inserted inside the existing one.
Most contractors use 4-inch or 5-inch PVC pipe for domestic well liners. In wells with caving conditions, bends, or very deep installations, steel casing may be a better choice because PVC may not hold up to the stress. The liner is lowered into the well with a seal on the bottom end, positioned at least 10 feet below the problem area. The seal traps any water or sediment that enters above the damaged zone within the space between the old casing and the new liner, keeping it out of your water supply.
For a permanent installation, the space between the inner liner and the outer casing should be sealed with cement or bentonite grout. Some contractors install seals on both ends of the inner casing to prevent contaminated water from spilling over the top of the liner and back into the well. Once a liner is in place, the well’s effective diameter is smaller, which may affect the type of pump you can install.
Disinfecting the Well
After cleaning and repairs, the well needs to be disinfected before you draw water from it. Shock chlorination kills bacteria introduced during the work and any organisms that have colonized the well during its dormant years.
The standard method is pouring household liquid chlorine bleach (unscented, with no additives) directly into the well. The amount depends on depth: roughly half a gallon to one gallon for wells under 100 feet, and one to one and a half gallons for wells between 100 and 200 feet. These are approximate amounts. Cloudy water or hand-dug wells with larger diameters need more. After adding the bleach, you run water through the system until you smell chlorine at every faucet, then let it sit for at least 12 to 24 hours. Afterward, you flush the system by running water through an outdoor spigot (away from septic systems, gardens, and streams) until the chlorine smell is gone.
Choosing and Installing a New Pump
Old wells that have been sitting idle almost always need a new pump. The type depends on your well’s depth and water level. For wells where the water level is within 25 feet of the surface, a shallow well jet pump installed above ground will work. Between 25 and 90 feet, you can use either a convertible jet pump in a deep-well configuration (two pipes instead of one) or a submersible pump lowered into the well itself. Beyond 90 feet, a deep well submersible pump is the standard choice.
The key measurement for pump sizing is the “pumping water level,” which is the depth to the water while the pump is actively running. This is always deeper than the static level because drawing water temporarily lowers the water table around the well. Your contractor should have this number from the pump test, or it may be on the original well driller’s report if you can locate it. The pump’s flow rate in gallons per minute should match your household demand. Count every fixture: each faucet, toilet, shower, and water-using appliance equals roughly one gallon per minute of needed capacity.
A pressure tank is installed alongside the pump to maintain consistent water pressure in the house and prevent the pump from cycling on and off with every small draw. Your contractor can size the tank based on the pump’s output and your household needs.
Testing the Water
Once the well is cleaned, repaired, disinfected, and pumping, you need to confirm the water is safe. Wait at least one to two weeks after shock chlorination before collecting a sample, so residual chlorine clears and you get a true reading of the well’s baseline water quality.
At minimum, test for total coliform bacteria, nitrates, total dissolved solids, and pH. These four parameters should be checked annually going forward. Beyond the basics, your testing should reflect what’s happening around the property. If the well is near agricultural land, add nitrite and pesticides. Near old mining operations, test for metals and corrosion indicators. If there’s a landfill, gas station, junkyard, or dry cleaner in the vicinity, test for volatile organic compounds, sulfate, chloride, and metals. Your local health department can tell you which contaminants are common in your area’s groundwater.
If the water comes back positive for coliform bacteria after disinfection, a second round of shock chlorination may be needed. Persistent contamination can indicate a structural problem, like a failed casing seal, that is allowing surface water into the well.
Safety During Restoration
Old wells pose real physical dangers. An uncapped or poorly capped well is a fall hazard, especially for children. Wells can also accumulate dangerous gases. Methane, carbon dioxide, and hydrogen sulfide can collect in the well bore and displace oxygen. OSHA classifies wells as confined spaces, and deaths from oxygen-deficient atmospheres in wells are documented, including a case in Pennsylvania where three people died from carbon monoxide exposure inside a well. Never lean into or enter an old well yourself. This is work for licensed professionals with the right equipment and atmospheric monitoring tools.
If you discover an old well on your property and decide not to restore it, most states require proper abandonment. This typically involves filling the well with cement or bentonite grout to prevent it from becoming a conduit for surface contamination to reach groundwater. A licensed contractor files the decommissioning report with the state.