If your water looks cloudy, leaves specks on fixtures, or clogs an aerator in your Wentzville home, a simple jar test can show whether solid material is moving through your plumbing. It is a homeowner check, not a lab test. It shows what settles out of a sample, but it cannot tell you what is dissolved in the water.
Public reports describe Wentzville tap water as very hard, and homes here draw on a mix of river water and groundwater. Private wells around the town are a different case. River-bottom alluvial wells and deep bedrock wells can both behave differently from city supply, and private wells are unregulated with no annual report to read. If you are on a private well, sediment matters more because nothing upstream is filtering the water before it reaches your fixtures.
What you need
- A clear glass jar with a lid
- A fresh sample from a cold tap
- A dark sheet of paper or a black cup to set behind the jar
- A notebook to record what you see at each check
How to run the test
- Run the cold tap for a while so the sample comes from the line, not from the faucet's outlet.
- Fill the jar, cap it, and shake it gently.
- Set the jar on a table out of direct sun and leave it undisturbed.
- Check it after a few minutes, again after an hour, and again the next morning.
- Write down the layers, colors and any clearing at each check.
Reading the layers
- Sand or grit is heavy and drops to the bottom within minutes. It often points to a sediment issue in the well or the line.
- Silt or fine clay forms a soft layer that settles slowly and may keep the water cloudy for hours.
- Rust-colored flakes can be iron particles. Iron is common in some river-bottom wells, so note whether the color appears more in the hot or the cold line.
- Dark or black specks may be manganese or organic matter. Do not assume which one from color alone.
- Floating bits are often organic debris or small air bubbles.
- Milky water that clears from the bottom up usually holds air, not sediment. Let it sit before you judge it.
Hardness is not sediment
Hard water usually shows up as white scale on faucets, showerheads and glassware, not as a layer that settles in the jar. If your jar is clear but your fixtures are crusty, the mineral content is the more likely cause. A jar test will not measure hardness, so do not read a clear sample as a sign that the water is soft.
What the jar cannot tell you
A jar tells you about particles you can see. It does not tell you about bacteria, nitrate, radium, lead or other dissolved substances, and it does not tell you the health status of the water. Those questions need a lab. For a private well, ask a lab about coliform bacteria, nitrate and, where the geology suggests it, radium. Ask the lab which sampling point to use so your result reflects the water you actually drink, whether that is before or after a tank or filter.
When to move from the jar to a lab
- Sediment appears after heavy rain or a period of flooding near the well
- The water turns cloudy or changes color suddenly with no clear cause
- Work has been done on the pump, pressure tank, casing or line
- You see sediment in the jar and also notice a change in taste or odor
- You are planning to install equipment and want to know what it needs to remove
Keep the results with your records
Save your jar notes with the date, weather and any recent work on the system. If the same layer shows up week after week, that pattern is more useful than a single sample. Bring the notes to a qualified water professional before you choose a filter or treatment, so the equipment matches what the water actually contains rather than what a fixture looks like.