Mehlville Water Hardness & Quality Report (2026)
Water Hardness
3.9 grains per gallon
Source
river
pH Level
8.4
neutral = 7.0
Lead
0.006 mg/L
✓ Below action level
TDS
513.7 mg/L
Est. Daily Cost
$0.18
energy & soap waste
Source: See methodology section below · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Mehlville, your appliances are currently losing 9% efficiency due to mineral buildup.
| Appliance | In Mehlville | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 7.4 yrs | 8.5 yrs | -13% |
| Washing Machine | 11.1 yrs | 12 yrs | -8% |
| Water Heater | 12.9 yrs | 15 yrs | -14% |
Regional Water Comparison
How Mehlville compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Mehlville, Missouri | 67 mg/L | 6.8 ppt | 🟡 Moderately Hard | river |
| Concord, Missouri | ≈ 180+ mg/L | 6 ppt | 🔴 Very Hard | river |
| Oakville, Missouri | ≈ 120–179 mg/L | 3.7 ppt | 🟠 Hard | river |
| Affton, Missouri | 67 mg/L | 6.3 ppt | 🟡 Moderately Hard | river |
| Lemay, Missouri | ≈ 120–179 mg/L | 5.8 ppt | 🟠 Hard | river |
National Benchmark
How Mehlville compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Mehlville | 67 mg/L | 🟡 Low |
| USA National Avg | 151 mg/L | 🟠 Moderate |
| Scarsdale Top Rated | 0.02 mg/L | 🟢 None |
Bring Scarsdale-quality water to your Mehlville home
Shop water softeners on Amazon.com →
What Makes Mehlville's Water Unique?
Local geology and source profile
Mehlville, in St. Louis County, Missouri, receives its water supply from American Water's Missouri-American Region, serving St. Louis County and St. Charles County. The utility sources raw water from the Missouri River and Meramec River, treated at regional facilities including the Howard Bend and Meramec treatment plants. Daily production averages 180 million gallons, distributed through an extensive network to residential, commercial, and industrial customers in the suburban area surrounding Mehlville.
The Missouri-Meramec watershed spans over 15,000 square miles, draining Mississippian-age limestone-dominated bedrock including the Ste. Genevieve and Salem Formations, as well as the Burlington Limestone and Warsaw Formation. These soluble carbonates naturally dissolve calcium and magnesium ions into river water as it flows through karst terrain. Glacial till and loess overburden further enhance mineral leaching, and alluvial aquifers along the river valleys provide minor groundwater blending, yielding a mineralized profile typical of Midwestern river systems.
Hard water causes scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan. White deposits on fixtures and soap scum are common, increasing detergent use and cleaning needs. Regular deliming of appliances and flushing heaters is advised; a whole-home water softener is highly recommended to protect plumbing and extend equipment life. Water quality meets EPA standards with typical pH 7.5–8.5 and lead and copper rule compliance through corrosion control. Testing covers over 150 contaminants with no MCL exceedances; treatment involves coagulation, sedimentation, filtration, and chloramination.
Geology & Source: Missouri and Meramec River watersheds; Mississippian Burlington Limestone, Warsaw Formation, Ste. Genevieve and Salem Formations — karst carbonate dissolution with glacial till and loess overburden yields hard river supply
Other Missouri Water Reports
Report an Issue
Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.
All reports are reviewed by our team. Thank you for supporting data quality!
Frequently Asked Questions
Is Mehlville's water safe to drink?
Do I need a water softener in Mehlville?
How does Mehlville compare to the USA average?
Data Sources & Methodology
Water quality data for Mehlville is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.
Water Hardness
Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.
pH
Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.
TDS — Total Dissolved Solids
Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.
PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances
EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.
Lead
Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.
Appliance Lifespan
Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.