If you live on a private well in Wentzville or the country around it, the most useful document for choosing a water test may already be in a folder in your house or at the county office. It is the well construction record, sometimes called the well log or driller's log. It shows how the well was built, what layer of ground it draws from, and where the water was first found. Read it before you order any test, because it can point you toward the right questions.
Why the record matters in this area
Wentzville sits in St. Charles County, and the groundwater under the area is not uniform. Homes near river bottoms may draw from alluvial wells, which are often shallower and more exposed to surface activity. Other homes draw from deeper bedrock wells. Public water reports for Wentzville describe very hard water, and the private well profiles that ring the city describe a different set of concerns depending on the aquifer. River-bottom wells are more often associated with iron, manganese, hardness, a rotten-egg sulfur smell, and bacterial or nitrate risk from farm runoff and septic systems. Deep bedrock wells are more often associated with very high hardness and naturally occurring radium. The well record helps you figure out which group your well probably belongs to.
What to look for in the record
- The date the well was drilled and the name of the drilling company listed on the form.
- The total depth of the well.
- The depth where the casing ends and whether the casing extends above the ground.
- The material noted at the water-bearing zone, such as sand, gravel, limestone, or shale.
- The static water level and the pumping level, if either was recorded.
- The type and depth of the grout or seal around the casing.
- Any water notes from the time of drilling, including color, odor, or sediment.
- A sketch or site map showing the well's distance from the septic tank, drain field, livestock areas, fuel storage, and property lines.
How the record shapes your test plan
A shallow well with sand or gravel listed at the water zone deserves a closer look at bacteria, nitrate, iron, manganese, and sulfur. If the record shows the well is close to a septic tank or drain field, nitrate and bacteria testing matter more, because those are the sources most often tied to nearby wells. If the record shows a deep well drawn from rock, hardness is likely to be a central issue, and a radium test is a reasonable question to ask a lab. Radium is a naturally occurring radioactive element found in some rock layers, and only a lab test can measure it. Testing for it does not tell you what to do, but it does tell you whether the question applies to your well.
A record that matches your well's location and depth still does not replace a water sample. It only helps you choose which tests to request. Water quality can change over time, so the record is a starting point, not a final answer.
When the record is missing or incomplete
Older wells may have no record at all, and some records are incomplete or hard to read. Start by asking the previous owner whether they have any papers from the well, and check your closing documents for mention of a well report. If the record cannot be found, the state agency that licenses well drillers may have a copy on file, or you can ask a local office about how to request one. A missing record is not a reason to skip testing. In that case, the sample itself becomes the main source of information, and a broader test panel may be the more practical choice.
Check the well and its surroundings
While you have the record in hand, walk the property with it. Compare what you see with what the record describes.
- Confirm the well cap is intact, with a screened vent that is not damaged or clogged.
- Look for signs of water pooling near the wellhead or casing.
- Check that the casing extends above the ground as the record describes, and that the ground slopes away from it.
- Note any septic lines, drain fields, livestock pens, or fuel tanks that sit closer to the well than you expected.
- Look for cracks or gaps in the concrete pad or seal around the well.
Anything that does not match the record is worth noting when you talk with a lab or the person who collects your sample.
A simple order of operations
- Find the well construction record, or confirm that none exists.
- Write down the depth, casing depth, water-bearing material, and location of the well.
- Make a simple sketch of nearby sources such as the septic system, livestock areas, and fuel storage.
- Decide which tests fit the pattern, and ask the lab about any tests that match the aquifer.
- Keep a copy of the record with your test results, so the next person who looks at the well has the full picture.
A well record is not glamorous, but it is one of the few documents that tells you what your well was built to do. Using it before testing helps you ask better questions and avoid guessing about which problem you are trying to solve.