Floodwater moves fast and leaves a mess in its wake. For homes that rely on a private well and a septic drainfield, that mess can put drinking water at risk and can overwhelm wastewater treatment. This guide gives clear actions for private well flood recovery and septic drainfield recovery after flood. You will find what to test, how shock chlorination works, what to avoid with your drainfield while the soil stays saturated, and when to bring in a licensed pro. I also link to CDC and EPA guidance for exact procedures and safety notes. If stormwater reached the living space, our team can help with extraction, drying, and sanitation right away.
Immediate steps after flooding
Stop using your well for drinking, cooking, or brushing teeth until you have disinfected the system and a certified lab says the water is safe. Use bottled water or boil water for a full minute at a rolling boil for any use that may reach your mouth. The CDC gives this rule for any flooded well because floodwater can carry sewage and many kinds of bacteria. You can review their recommendations on the CDC well disinfection page.
Look at your well cap and casing once water drops. If the cap was under floodwater, assume the well is contaminated. Keep the power off to the pump until a contractor checks wiring and controls for damage. Remove visible debris around the well head so grit does not drop into the casing. Heavy damage calls for a licensed well contractor before any chlorination attempt. State health and extension sources echo this path for safety and for success during private well flood recovery.
Shift your attention to your septic system right away. If the drainfield area still looks saturated or has standing water, do not send any wastewater to the system. Toilets, showers, laundry, and dishwasher use should be paused. The EPA warns that a saturated soil field cannot treat wastewater. Using it during that time can push sewage to the surface or back into the house. Review the EPA page on septic systems after a flood for what to avoid until the soil dries.
If floodwater reached the inside of your home, call for rapid water removal and sanitation to cut mold risk and protect surfaces. Our water damage restoration team responds day or night. If the flooding came from a severe storm, we also provide storm damage restoration to secure the property and set a drying plan.
Testing your well after a flood
Plan testing before you start any shock chlorination. After a flood, the key tests are total coliform and E. coli. These indicate if bacteria from sewage have reached your supply. Many states also recommend nitrate testing, since levels can rise after heavy rain. The CDC explains these test choices and provides timing advice for post flood recovery. See their guidance for private well flood recovery on the CDC page.
Contact your local health department or a certified lab for sample bottles and a simple set of instructions. Ask for an accredited lab for drinking water. Labs usually provide a sterile bottle and a short form. They also explain transport timing since the bacteria sample has a short hold time. If you cannot find a lab list on your county page, a state health department page often carries a directory. The Minnesota Department of Health publishes clear steps for flooded well testing and gives a detailed walkthrough that many homeowners find helpful. You can read it on the Minnesota DOH flooded wells page. Iowa also publishes easy test guidance on the Iowa DNR private wells site and through Iowa State University Extension.
Many homeowners wonder about timing. If you disinfect the well, the CDC advises waiting seven to ten days after shock chlorination before collecting a bacteria sample. This delay gives the chlorine time to flush out so the lab result reflects the true water quality. If the sample comes back positive for total coliform or E. coli, repeat disinfection and test again. Continue until you receive a clean report. Keep the bottled or boiled water routine in place the whole time.
If a pump, casing, or cap looks damaged, or if the well was submerged and you see sand or silt in your water, schedule an inspection with a licensed well contractor before you sample. Damaged equipment can recontaminate water or fail during disinfection. For some shallow dug wells that draw from near surface water, chlorination often does not hold. In those cases a contractor may suggest deeper construction or other solutions.
Shock chlorination basics
Shock chlorination is the standard method to disinfect a flooded private well. It uses a strong chlorine solution to kill bacteria in the well and in the home plumbing. The CDC and state health departments lay out the steps. Follow those steps closely to protect your pump, your plumbing, and yourself. A good place to start is the CDC how to disinfect page. The Minnesota Department of Health also lists bleach amounts for different well sizes and gives clear reminders on safety gear and contact times on their flooded well page.
Begin with safety. Cut power to the pump at the breaker before you open any part of the system. Do not turn power back on until wiring and controls look dry and intact. Wear gloves and eye protection when handling bleach. Work in a well ventilated space. Never mix chlorine with other cleaners. Keep children and pets away during the process.
Prepare the well. Clear debris from the well cap area. If the cap seal looks damaged, plan to replace it. The amount of bleach you need depends on well depth and casing diameter, and also on whether the well was under floodwater. A deeper or larger diameter well needs more solution. State tables give the exact amount for your well type. Do not guess. Follow a state table or ask a licensed well contractor to calculate the dose. The Alabama Cooperative Extension provides a readable summary for homeowners on flooded wells and shock chlorination that may help as you plan.
Use unscented household bleach. Dilute it in clean water before adding it to the well so that it spreads evenly. Pour the solution into the well. Then circulate the chlorinated water through the well and the entire plumbing system. One way is to attach a hose to an outdoor faucet and run water back into the well to mix the solution. Then go to indoor taps one at a time. Run cold water until you smell chlorine. Do this on each line, including showers, tubs, and laundry sinks. Run hot water too so the water heater gets the solution. Bypass any softeners and filters before you start so you do not damage cartridges and media. The CDC and several state guides call out these steps so you can reach every part of the plumbing.
Let the system sit with chlorine for at least twelve hours. Many state guides say eight to twelve hours at minimum. Longer contact often gives better results. Do not use the water during this period for drinking, cooking, bathing, or laundry. After the contact time, flush the system until the chlorine smell fades. Use an outdoor hose away from lakes, streams, and ponds. Do not discharge chlorinated water directly to surface water. Avoid soaking lawns and gardens with heavily chlorinated water. Spread the flushing over time, and over different areas of the yard, to protect plants. The Minnesota Department of Health describes safe disposal practices on their flooded well page.
Wait seven to ten days after the flush before taking a bacteria sample. Collect the sample from a clean indoor tap using the lab instructions. Keep the sample cool and deliver it quickly. If the lab finds bacteria again, repeat shock chlorination and test once more. If repeated attempts do not clear the problem, hire a licensed well contractor to inspect the system for structural issues, hidden biofilm, or dead end plumbing runs that can harbor bacteria.
Do not attempt to disinfect if you suspect electrical damage, pump failure, or a cracked casing. Hire a pro. Repairs inside the well usually require special tools, training, and safety practices.
Septic drainfield recovery tips
Floods push water into the drainfield and the surrounding soil. Treatment relies on unsaturated soil below the trenches. When that zone fills with water, treatment stops. Wastewater sent to the field during this period can rise to the surface or spill back toward the house. It can also wash out solids and push silt into the field. That is why the EPA says to stop using the system until the soil drains and the water table drops. Review their do and do not advice on the EPA septic after flood page.
Cut household water use to the lowest possible level. Skip laundry. Delay dishwashing. Shorten showers or bathe at a safe location outside the home. Flush toilets only when needed. This reduction protects the system and lowers the chance of a sewage backup. Keep floodwater and stormwater away from the drainfield area. Redirect roof leaders and yard drainage. Do not drive heavy equipment over the field. Do not dig or add soil to the trenches. Wait for the area to dry and for groundwater to recede before any service or pumping.
Do not pump the septic tank while the field or yard is saturated. Pumping at that time can cause the tank to lift or shift. It can also break inlet and outlet pipes. The EPA and many state agencies flag this risk for flooded sites. When the field has drained and the soil firms up, schedule an inspection and a pump out. Ask the contractor to check for silt, sediment, or structural damage. Lift stations and pump chambers may also need cleaning and service.
Watch for warning signs as the soil begins to dry. Look for slow drains, gurgling, or sewage odors. Look for wet spots or surface ponding over the drainfield. Those signs can mean that silt clogged the drains or that the field cannot accept water yet. A licensed septic contractor can diagnose these issues and guide the next steps. Additives do not fix flood damage. Good practice is inspection, cleaning, and careful use as the system recovers.
If sewage entered your home during the flood, clean and disinfect hard surfaces with a bleach solution. The EPA suggests a ratio of half a cup of household bleach per gallon of water for general disinfection. Porous materials that soaked up sewage often need removal and disposal for health reasons. Large sewage losses carry hazards like gases and pathogens. For heavy contamination, call trained cleanup crews. Our team handles sewage cleanup and structural drying, with the protective gear and sanitation steps needed. You can reach us anytime through our water damage restoration page.
Protect plumbing and equipment
Many homes run water through softeners, filters, or reverse osmosis units. Floodwater can foul this equipment. Before chlorination, bypass or disconnect these systems so bleach does not damage media and cartridges. After disinfection and once tests are clean, service filters and the softener before placing them back in line. The CDC backs this practice in its flooded well guidance. Iowa State University Extension gives similar direction for post flood checks of treatment equipment. You can review those notes on the ISU Extension page.
Prevent backflow during the flood. Plug basement floor drains with test plugs if you have them. Close any drain traps that might allow floodwater to enter the plumbing. Disconnect garden hoses so floodwater does not siphon back into the system. If you have a sump that discharges near the well or drainfield, extend that discharge farther away during recovery so it does not recycle water into the sensitive area.
Handle bleach with care. Keep the liquid away from aluminum and some stainless steel fittings to avoid corrosion. Do not mix bleach with ammonia or acids at any time. Ventilate spaces during flushing. Keep windows open. Use fans to push air out. Collect and redirect flushing water to lawn areas in small sessions. Do not dump chlorinated water into streams, ponds, or storm drains. The Minnesota Department of Health lists disposal cautions and can guide you on local rules. Their page on flooded wells remains a strong reference for these actions.
If mold has started on damp surfaces inside, act fast. Mold can grow within two days on porous material after wetting. Dry the building quickly and remove unsalvageable materials. We share practical tips on our page about types of mold and how wet conditions lead to growth. For deep cleaning and drying, contact our crew for help. You can also browse more tips on our articles page.
When to call a professional
Some conditions call for licensed help at once. If the pump will not start, cycles strangely, or trips breakers, call a well contractor. If you see a broken cap, a cracked casing, or a well that was scoured by moving water, do not run the pump. If your water turns cloudy or gritty as the flood recedes, stop using it and call a contractor. These are classic red flags noted by state health departments and cooperative extension sources.
Call a licensed septic contractor if the drainfield shows persistent wet spots after the rest of the yard dries. Call if you smell sewage near the field or house. Call if sewage backed into tubs or floor drains during or after the flood. Call if your tank or pump chamber likely filled with silt or if you lost power to a lift station for an extended period. The EPA notes that sewage handling carries hazards. Trained contractors have the tools and protocols to pump safely, clean components, and check for damage.
If floodwater rose into living areas, professional water removal and sanitation can prevent secondary damage and cut health risks. Our crews can extract standing water, set drying equipment, remove unsalvageable materials, and apply disinfectants that meet health guidance. Reach out at any hour through our water damage restoration page or get rapid help on our storm response page.
FAQs on well and septic recovery
How long until I can drink my well water
Do not drink it until you disinfect and then receive a clean lab result for total coliform and E. coli. The CDC recommends waiting seven to ten days after shock chlorination before sampling so that the test reflects true water quality. Review the timing on the CDC page.
Can I disinfect my well myself
Many homeowners can, if the well and pump are intact. Follow CDC and your state health department steps. Use unscented bleach, protect yourself, and reach every tap. If the well was submerged, the pump is damaged, or the casing is cracked, hire a licensed well contractor. See the Minnesota DOH flooded wells guide for a clear walkthrough.
What should I test for after a flood
Test for total coliform and E. coli. Consider nitrate. Some areas may also suggest other tests if fuel, pesticides, or industrial chemicals were present in floodwater. Ask your local health department or certified lab. The CDC lists these choices on its well disinfection page.
Is a shallow dug well safe after flooding
Dug wells can be hard to disinfect because they draw from near surface water. Many state guides say repeated contamination is common. A licensed well contractor can discuss options, such as deeper construction. The Alabama Cooperative Extension gives a plain language discussion on flooded wells.
Do I need to bypass my water softener during chlorination
Yes. Bypass or disconnect softeners and filters before you add chlorine. After you flush and receive clean results, service filters and resin before use. The CDC and ISU Extension both call for this step. See ISU Extension guidance on private wells after flooding.
Can I use chlorinated flush water on my lawn
Use caution. Do not send large volumes of highly chlorinated water to one spot. Spread it out and flush in shorter sessions. Keep it away from streams and ponds. The Minnesota Department of Health gives disposal advice on its flooded well page.
Should I pump my septic tank right away
No, not if the soil is still saturated. Pumping in saturated conditions can float or damage the tank. Wait until the drainfield area drains and firms up, then schedule an inspection and pump out. The EPA explains this risk on its page about septic systems after a flood.
What if my water is still cloudy after flushing
Stop using it and call a licensed well contractor. Cloudiness or grit can signal damage or infiltration of silt. The contractor can inspect the casing, screen, and pump and may advise a deep cleaning or repair.
Can I pour bleach into my well without calculating a dose
No. Overdosing can damage parts and does not guarantee better results. Underdosing can fail to disinfect. Follow a state table or a contractor calculation. The Minnesota Department of Health provides dose tables by well size on its flooded well page.
How often should I test my well after recovery
After you receive a clean result, test again if you notice a change in taste, color, or odor. Many agencies suggest routine bacteria testing twice per year for private wells. Ask your local health department for a schedule. The CDC provides ongoing testing advice on its well page.
Printable checklist for homeowners
Keep this short list on the fridge to guide your next steps during private well flood recovery and septic drainfield recovery after flood.
- Do not drink or cook with well water until you disinfect and receive a clean test. Use bottled water or boil for a full minute. See the CDC well page.
- If the drainfield is saturated, pause all heavy water use. Do not pump the tank until the soil dries. See the EPA septic after flood guide.
- Contact your local health department or a certified lab for bacteria sampling kits and instructions.
- If the well was submerged or equipment looks damaged, schedule a licensed well contractor inspection.
- Bypass filters and softeners before shock chlorination. Wait seven to ten days after disinfection before sampling.
- For sewage in the home, disinfect hard surfaces, discard porous items that soaked up waste, and call trained pros for heavy cleanup. Visit our water damage page for rapid help.
Flood recovery for wells and septic systems takes patience, clean steps, and good timing. Stop using your drinking water until tests are clean. Pause septic use while the field is wet. Disinfect with the right dose and reach every tap. Flush safely to protect streams and soil. Test again until you have two clean results if your state suggests it. If pumps fail or sewage backs up, call licensed help. If floodwater entered the building, our water damage restoration team is ready day or night. For storm response and board up, visit our storm restoration page. You can also reach our office quickly through our contact page for a prompt call back. With careful steps and the right help, your water can be safe again and your septic system can return to service.