Methodology · 2026 grading period
How Grades Work
Our report card grades water treatment providers the way a county report card grades a school: a single letter for overall fit, built from weighted marks in four subjects. This page explains what the letters mean, how the criteria are weighted, and where editorial judgment comes in.
What each grade means
| Grade | Meaning |
|---|---|
| A+ | Exceptional across all four criteria. Fast, direct response; genuine in-home testing at no cost; straight answers on cost before commitment; and deep, verifiable roots in St. Charles County. Reserved for a standout, and issued once this period. |
| A / A- | Excellent on most criteria with only minor gaps. A provider a county homeowner can call with confidence. |
| B+ / B | Solid and credible. Established products and a professional sales process, typically delivered through a dealership or national structure rather than a county-based operation. |
| B- | Still a reasonable choice, with more of the experience depending on which dealer or office covers your address. Local fit is harder to predict in advance. |
| C range | Mixed fit for this county on our criteria. Worth a look only with careful questions about response, testing, and cost structure. No provider on the current card falls here. |
| D / F | Poor fit on our rubric. We would not feature a provider graded here. No provider on the current card falls in this range. |
| N/A | Not graded. Used for options that fall outside a provider relationship, such as big-box self-install equipment, where our four criteria cannot be applied fairly. |
Criteria and weights
Every graded provider is scored on the same four subjects. Weights reflect what county homeowners tell us matters most after the sale, not just during it.
- Response 30% How quickly and directly a homeowner in the county can reach a human, get a visit scheduled, and get follow-up after installation. A local phone line that gets answered outranks a national queue.
- Testing 25% Whether the provider tests your actual water before recommending equipment, what the test covers (hardness, iron, chlorine, and well-specific issues), and whether it costs you anything.
- Pricing clarity 25% Willingness to explain cost structure in plain terms before an in-home commitment: how quotes are built, what is included, and what ongoing costs look like. We grade the clarity of the process, not the price itself.
- Local presence 20% Ownership, staffing, and service footprint in and around St. Charles County: St. Charles, St. Peters, O'Fallon, Wentzville, Lake St. Louis, Cottleville, and the surrounding towns. Companies rooted here score higher than territories serviced from elsewhere.
Editorial judgment statement
Grades on this site are the editorial judgment of St. Charles Water Ratings, applied through the weighted criteria above. They are an assessment of fit for St. Charles County homeowners. They are not derived from complaint databases, regulatory actions, user-submitted reviews, or any claim about another company's conduct. A B or B- on this card is not an accusation; it means a provider scored lower than our top pick on criteria that reward county-level roots and transparency. Reasonable people can weigh these factors differently.
Where we state facts about a provider, such as ownership structure, service model, or product design, we keep them general and verifiable. We do not publish pricing figures, customer counts, or performance statistics we cannot support.
Review cadence and compensation
Grades are assigned per grading period and reviewed when a provider's local situation materially changes. The current card covers the 2026 period and was last reviewed on July 13, 2026.
This site features sponsored placements, and we may be compensated when you request a quote through our forms. Compensation does not change the criteria or the weights described above; the full disclosure appears in the footer of every page.