A basement flood in St. Louis is stressful enough without also wondering whether the water coming out of your taps is safe. Heavy rain, a sewer backup, or water pooling against a foundation can each leave a basement soaked, but they do not all affect your household water the same way. This guide walks through a practical way to sort out what happened and whether your water needs a closer look.
Figure out where the water came from
Start by describing the flood in plain terms. Floodwater from heavy rain usually enters through walls, floors, window wells, or cracks. A sewer backup usually shows up first at floor drains, laundry tubs, or the lowest toilet or shower in the house. Write down what you saw and where, along with the date and whether the water had been standing or draining.
Those notes matter. They help you explain the situation accurately when you call your water utility, a licensed plumber, or a testing lab, and they give you a record if an insurance claim or a repair question comes up later.
Check whether your water supply is affected
Most St. Louis homes draw water from a public system, while some properties in outlying areas use a private well. The steps differ, so confirm which one you have before you do anything else.
- If you are on public water, call your water utility and ask whether any boil or do-not-drink notice applies to your address. Follow any official instruction exactly, even if the water looks clear.
- If you have a private well, treat flood water as a reason to take the well seriously. Surface water can reach a well through the ground, and a well that was submerged or had water pool around the casing should be inspected before its water is used for drinking or cooking.
- If sewage came up through your drains, assume the fixtures and drain lines are contaminated until they have been cleaned and checked, and avoid using water from those fixtures for drinking or food preparation.
Decide what to test
A home test strip or a basic meter can give you a rough sense of some conditions, but it cannot confirm that your water is safe to drink. For that, you need a certified laboratory. In most flood situations, the first test to ask about is bacteria, since that is the main concern when floodwater or sewage has been in contact with a water source.
- Ask for a total coliform and E. coli test on the water you use for drinking and cooking.
- If your home has a private well, ask the lab whether a broader panel is appropriate, based on what the flood contacted and what you know about your area.
- If the flood left visible residue, odor, or staining, note those details and share them with the lab, since they can shape which additional tests make sense.
- Retest after any repair, disinfection, or cleanup work that touches the water system, because a single clean result taken during the cleanup may not reflect the final condition.
Collect the sample the right way
A sample is only as useful as the way it was collected. Use the bottle provided by the lab, and do not rinse it or add anything to it. Remove the faucet screen or aerator first, clean the faucet with a disinfecting wipe, and let the cold tap run until the water has been running for a few minutes before filling the bottle. Keep your fingers off the inside of the cap, and follow the lab's instructions for how quickly the sample needs to reach them and how it should be stored in the meantime.
Handle cleanup carefully while you wait
Cleanup and testing often happen at the same time, so a few habits help. Never mix cleaning products, especially bleach with ammonia or other cleaners, because the fumes can be dangerous. Ventilate the space while you work, wear gloves and eye protection, and keep children and pets out of the flooded area. Discard food that touched floodwater or sewage, and do not run appliances that draw water until you have confirmed the supply is safe to use.
If anyone in your home feels unwell after the flood, contact a doctor and mention the flood, since a medical professional is the right person to evaluate symptoms. Your water test results and the notes you wrote down will help with that conversation.
What to do next
Once you know where the water came from and which supply it touched, the path forward is usually clearer. Confirm any local notice, decide which samples to send, follow the lab's collection steps, and keep your records together. A St. Louis home that has been through a flood deserves a careful check of its water, and a few organized steps now can save you guesswork later.