If you live in St. Peters, your water supplier publishes an annual water quality report that lists what was tested in the public supply and what was found. The document can look dense, but the same handful of terms appear again and again. Knowing what they mean helps you decide whether a softener, a filter, or a closer look at your water is the next step.
Where to find the report
Look for the report on the supplier's website, or ask the utility for a printed copy. Most reports arrange results in tables. Each row names a substance, the level detected, a range if one is given, and the standard that applies. Read the notes at the bottom as well, since they often explain the sampling period and any violations or follow-up steps.
Hardness
Hardness describes the calcium and magnesium dissolved in water. It is why tap water in St. Peters can leave spots on glassware, scale in kettles, and a film on tile. Public reports in the area describe the water as hard, which is why softening comes up so often here. Hardness is reported in a unit that may differ from the scale on your softener's control display, so check how the report and the equipment match before you change any setting.
Chloride and sodium
Chloride and sodium are dissolved minerals that can show up in local water from natural sources and runoff. Reports in the area note high chloride and sodium, so these rows deserve a careful read. Sodium matters in one more way if you soften. A softener swaps hardness minerals for sodium, so the water leaving the unit carries more sodium than it did before. If your household follows a sodium-restricted diet, talk with your own clinician about which figures apply to you.
Disinfection byproducts: TTHMs and HAA5
Water is disinfected to control germs, and the disinfectant can react with natural organic matter to form byproducts. Two groups appear in many reports. TTHMs, or total trihalomethanes, and HAA5, or five haloacetic acids, are usually listed as group results taken at several points in the distribution system. Their levels can vary with season, treatment practices, and where the sample was taken. Softening and disinfection byproducts are separate problems. A softener is not designed to remove them, so the report is the place to see them and the right place to ask the utility about any trend.
Other terms you may see
- Detected level: the highest or average amount found in the sampling period.
- Range: the lowest and highest results when more than one sample was taken.
- Standard or limit: the regulatory threshold the substance is compared against.
- Turbidity: how cloudy the water is, which relates to particles in the supply.
- Chlorine residual: the disinfectant left in the water as it travels through pipes.
- Violations and notices: any required public notices and what the utility did about them.
Private wells near St. Peters
A public report does not describe a private well. If your home draws from a well, you need your own testing. Shallow wells and septic-dense areas can carry coliform bacteria, which is commonly checked with a lab sample. Deeper aquifers can hold naturally occurring radium and uranium. Groundwater in some alluvial areas near the former Weldon Spring chemical and ordnance site has a documented uranium hotspot, so well owners in that part of St. Charles County should test for uranium specifically rather than relying on general assumptions.
Turning the report into a plan
- Note the hardness result and whether the report calls the water hard.
- Read the chloride and sodium rows, and decide how much sodium you want to add if you soften.
- Check the TTHM and HAA5 rows and any notes that describe a trend.
- Look for violations, notices, or follow-up items, and call the utility with questions.
- If you own a private well, schedule lab testing for the substances that matter in your area.
- Bring the report and your test results to any decision about softening or filtration, so the equipment you choose matches the water you actually have.