If your Arnold home runs on a private well, a bacteria test belongs near the top of your list. Bacteria in well water are not visible, have no taste or smell, and do not change how water looks in a glass. A clear sample tells you nothing about bacteria, so the only dependable way to know is to collect a sample and send it to a lab.
What the test looks for
Total coliform is a broad group of bacteria found in soil, plants, and animal waste. Its presence in a well suggests that surface water or other outside material may be reaching the well or its plumbing. E. coli is a specific type within that group that is usually associated with human or animal waste. Labs typically report each one as present or absent in the sample, so you will read a simple yes or no rather than a number to compare against a chart.
Why some Arnold wells deserve closer attention
Private wells around Arnold vary in depth, age, and construction. Shallow wells and older wells can have worn casings, cracked well caps, or seals that no longer fit tightly, and each gap gives surface water another route in. Heavy rain, runoff, or flooding can carry surface water toward a well site. If your well is shallow, older, or has been through a storm, add a bacteria test to your routine rather than waiting for a problem to show up.
Testing is also worth doing after any repair to the pump, pressure tank, or piping, because work on the system can open a path for bacteria.
How to collect a sample
- Get a sample bottle from a state-certified lab. Do not use a bottle from another source or reuse an old container.
- Do not rinse the bottle or touch the inside of the bottle, the lid, or the cap.
- Remove any hose, screen, or aerator from the tap you plan to use, and wipe the outlet with alcohol. Let it air dry before sampling.
- Follow the lab's flushing instructions, then fill the bottle to the marked line without letting the bottle touch the faucet.
- Label the bottle with the date and time, and keep it cool as the lab directs.
- Deliver the sample within the time window the lab sets, since holding times affect the result.
Reading the result
A negative result means coliform and E. coli were not found in that sample on that day. A positive result means the water has bacteria in it, and you should act promptly. The lab report usually lists what it found and may include recommendations. Your county or state health office can also explain your options and next steps.
Next steps after a positive result
- Inspect the well cap, casing, and any vents or openings for cracks, gaps, or damaged seals.
- Look at the area around the well for surface runoff, low spots, or drainage paths that may carry water toward it.
- Ask a licensed well contractor to inspect the system and recommend a disinfection procedure.
- Retest after any repair or disinfection to confirm the result has changed.
Keeping a record
Save each lab report with its sample date. Over time, these reports show whether your well is staying consistent or changing after storms, repairs, or seasonal shifts. Keep them with your notes on maintenance so you can connect any change to a specific event.