Old Jamestown Water Hardness & Quality Report (2026)
Water Hardness
~120–179 mg/L
Hardestimated · not lab-verified
Source
river
pH Level
7.8
neutral = 7.0
Lead
0.003 mg/L
✓ Below action level
TDS
259.6 mg/L
Est. Daily Cost
$0.40
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 Old Jamestown, your appliances are currently losing 20% efficiency due to mineral buildup.
| Appliance | In Old Jamestown | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 6.8 yrs | 8.5 yrs | -20% |
| Washing Machine | 9.6 yrs | 12 yrs | -20% |
| Water Heater | 12 yrs | 15 yrs | -20% |
Regional Water Comparison
How Old Jamestown compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Old Jamestown, Missouri | ≈ 120–179 mg/L | 4.7 ppt | 🟠 Hard | river |
| Florissant, Missouri | ≈ 120–179 mg/L | 5.1 ppt | 🟠 Hard | river |
| Spanish Lake, Missouri | ≈ 180+ mg/L | 4.2 ppt | 🔴 Very Hard | river |
| Ferguson, Missouri | ≈ 120–179 mg/L | 4.2 ppt | 🟠 Hard | river |
| Hazelwood, Missouri | ≈ 120–179 mg/L | 6.3 ppt | 🟠 Hard | river |
National Benchmark
How Old Jamestown compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Old Jamestown | ≈ 120–179 mg/L | 🟠 Moderate |
| USA National Avg | 151 mg/L | 🟠 Moderate |
| Scarsdale Top Rated | 0.02 mg/L | 🟢 None |
Bring Scarsdale-quality water to your Old Jamestown home
Shop water softeners on Amazon.com →
What Makes Old Jamestown's Water Unique?
Local geology and source profile
Old Jamestown, Missouri, is served by the City of St. Louis Water Division, which supplies water to unincorporated areas of St. Louis County including Old Jamestown. The utility operates two major treatment plants: the Howard Bend Plant, sourcing from the Missouri River, and the Chain of Rocks Plant, sourcing from the Mississippi River. This mixed surface water supply serves over 1.2 million people across the metropolitan region, with Old Jamestown receiving treated river water distributed through extensive pipelines. The system maintains compliance with state and federal standards as reported in annual Consumer Confidence Reports.
The watershed encompasses the upper Missouri and Mississippi Rivers, draining vast agricultural and urban lands across Missouri and surrounding states. Water percolates through Ordovician and Mississippian limestone and dolomite formations — including the Burlington and Joachimi Limestones and Ordovician karst structures such as the Potosi and Gasconade Dolomites — which dominate the regional geology. These soluble carbonate rocks dissolve readily, releasing calcium and magnesium during river flow and groundwater recharge. Karst features amplify mineral leaching, shaping the moderately hard to hard water profile typical of St. Louis County supplies.
Hard water in this supply leads to scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan. Kettles and faucets may develop limescale deposits, while laundry feels stiff without softeners. Periodic vinegar descaling and annual water heater element checks are recommended; a water softener helps prevent glassware spotting and extends plumbing life. The 2025 City of St. Louis Water Quality Report confirms EPA compliance for pH (typically 7.5–8.5), lead, and copper, with no MCL violations; treatment includes coagulation, sedimentation, filtration, and chloramination.
Geology & Source: St. Louis County — Missouri River via Howard Bend Treatment Plant and Mississippi River at Chain of Rocks Plant; Ordovician Potosi and Gasconade Dolomites and karst limestone dissolve calcium and magnesium, imparting hard character
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 Old Jamestown's water safe to drink?
Do I need a water softener in Old Jamestown?
How does Old Jamestown compare to the USA average?
Data Sources & Methodology
Water quality data for Old Jamestown 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.