Water is one of the few parts of a house you can't inspect from the front walk. Pipes run behind walls, the water heater sits in a closet, and the source may be a city system or a private well that nobody has touched in years. If you are buying a home in St. Louis, the water deserves the same attention you give the roof and the foundation. This guide covers what to ask for, what to check yourself during your inspection window, and how to read what comes back.
Start by finding out where the water comes from
Your first question is the simplest one: is the home on municipal water or a private well? The answer changes everything else on this list.
- Municipal water means the home connects to a public system. Ask the seller or your agent for the most recent annual water quality report for the address or service area. These reports list what the provider tested for and what it found.
- A private well means the owner is responsible for the water. Ask for the well depth, the date of the last service, and any lab tests on file. Well water in the St. Louis area is not tested automatically, so the absence of records is itself useful information.
What to request from the seller
Sellers often have more paperwork than they realize. Ask for the following in writing:
- Any water test results for the property, with the date and the name of the lab that ran them.
- Records for a water softener, filter, or other treatment equipment, including service dates and any replacement history.
- Information about plumbing repairs, a repipe, or a water heater replacement in the last several years.
- For a well, the location of the well and septic system, and any pump or pressure tank repair records.
If the seller has no records, that does not mean the water is bad. It means you will need to test it yourself before you commit.
Check the service line and the plumbing
The water that reaches the faucet is only as clean as the pipes that carry it. Older homes in St. Louis may have plumbing materials that were common in past decades, and the pipe that runs from the street to the house is a separate question from the pipes inside the walls. Ask your water provider whether it has records on the service line material for the address. Your inspector can also tell you what the visible piping looks like at the water heater and the main shutoff, and whether there are signs of past leaks or patch repairs.
Run your own test during the inspection window
A home test kit will not replace a certified lab, but it can show you whether anything obvious needs follow-up. Keep your sampling simple:
- Collect a sample from a cold tap that the seller has not recently used to flush the system, so the reading reflects typical household water.
- Use a clean container, and follow the kit's instructions for timing and temperature.
- Test for the basics first, including hardness, chlorine, and pH, then add more specific tests if the results or the home's history raise a question.
- If the property is on a well, send a sample to a state-certified lab, which can test for bacteria and the wider set of substances that a kit cannot measure.
Do the testing before the inspection period ends, so that you still have room to negotiate, ask for repairs, or walk away.
Reading the results without panic
Lab reports use units and reference values that can look alarming to someone who has never seen them before. Read the report line by line. Note which results are listed as detected, which are below the reporting limit, and which have an official standard attached. A result above a standard is a reason to ask questions and possibly to test again. It is not a diagnosis of anything in your household, and it should not be read as a measure of how the water will taste or perform in your appliances.
If a result concerns you, call the lab and ask what the result means for the specific substance and the way you plan to use the water. Ask your local health department whether the substance is a concern for private wells in your area. Keep copies of every report, since they will be useful if you need a treatment system later or if you sell the home.
When the answer is still unclear
Some homes in St. Louis have water that tests fine on a single day and still causes problems in daily life. Staining, scale, and odor can come from plumbing, a water heater, or a treatment system rather than the source. If the seller's history and your own tests do not explain what you are seeing, get a second opinion from a licensed plumber or your inspector before you accept the house as it is. Taking a few extra days now costs far less than discovering a water problem after the closing papers are signed.