If you draw water from a private well in or around Lake St. Louis, a lab report is only as useful as the sample behind it. Many results come back questionable not because the water is bad, but because the sample was collected, labeled, or shipped in a way the lab could not fully trust. A chain of custody form is the paper trail that records who handled a sample from the moment it was filled until the lab opened it. Knowing what goes on that form, and why, helps you get a result you can act on.

What the form does

The form travels with the sample bottles. It lists the sample identity, the source, the date and time of collection, the tests requested, and each person who handled the bottles along the way. Labs use it to confirm that the bottles they receive match the description and that nothing was swapped or changed before analysis. Some labs include the form in the kit. Others ask you to fill out their own version online. Either way, the details matter, and a missing signature or vague location can delay or limit your report.

Gather your details first

  • The exact service address and the sampling location on the property
  • Whether the well is shallow, such as a river-bottom well, or a deeper bedrock well, if your records show it
  • Any water softener, filter, or other treatment unit that sits ahead of the tap you plan to use
  • Recent plumbing work, pump service, or well disinfection, with dates if you have them
  • The tests you want, written down so the request on the form matches your kit

Sampling point matters a great deal. For most well tests, collect from an outdoor or utility tap close to the wellhead, before any softener, filter, or aerator. If you want to know how treatment changes the water, the lab can run a second set after the treatment unit, but label each set clearly so the two results are never mixed up.

Collect the sample cleanly

  1. Wash your hands and dry them. Avoid touching the inside of the bottle or cap.
  2. Remove any aerator or screen from the tap and wipe the outlet with a clean cloth.
  3. Let the water run until it is steady, then fill the bottles as the kit directs.
  4. Do not rinse bottles that contain a preservative. Rinsing can wash it out.
  5. Cap each bottle tightly and label it right away with the sample ID, date, time, and your initials.
  6. Write the same details on the chain of custody form, then sign and date it.

Keep the custody record intact

Every handoff needs a signature. If you collect the sample and drive it to a drop-off point, you sign when you leave it. If a courier or the lab's receiving staff takes it, they sign when they receive it. Keep your copy of the form and any tracking or receipt information. If a signature is missing at any step, call the lab before you assume the sample will be analyzed. Ask them, not a neighbor or an online forum, what they will accept.

Shipping and holding times vary by test and by lab. Some samples must be kept cool and delivered within a set window. Read the instructions that came with the kit, and do not leave bottles sitting in a hot vehicle while you run other errands.

Why Lake St. Louis wells deserve careful records

Lake St. Louis sits in St. Charles County, and the water supply in the area draws on a mix of river water and groundwater. Private wells nearby can show heavy iron and manganese staining in river-bottom wells, a rotten-egg smell from deeper bedrock wells, nitrates linked to agricultural runoff or septic systems, coliform and E. coli contamination, and naturally occurring radium in the deep eastern Missouri bedrock aquifers. The former Weldon Spring cleanup site also lies within the wider service area. Current municipal radium readings are within limits, but that does not describe a private well. Because the stakes of a misread sample are real, a clean custody record is worth the extra minute it takes.

Common mistakes to avoid

  • Filling bottles from a faucet that has a softener, filter, or aerator in front of it
  • Leaving the sampling location vague, such as just writing kitchen sink
  • Forgetting to note a recent rain event, pump repair, or disinfection, which can affect results
  • Mixing bottles from different taps into one bag without separate labels
  • Signing the form before the sample is actually sealed and labeled

When to call the lab

Call the lab before you collect if the instructions are unclear, if you are unsure which tests fit your well, or if you do not know whether a treatment unit sits ahead of your sampling point. Ask about hold times, preservatives, and what happens if a signature is missing. A short call at the start prevents a repeat sample later, and it gives you a record you can trust when you decide what to do next with the results.