Smithtown Water Hardness & Quality Report (2026)
Water Hardness
2.8 grains per gallon
Source
reservoir
pH Level
7
neutral = 7.0
Lead
0.007 mg/L
✓ Below action level
TDS
135 mg/L
Est. Daily Cost
$0.13
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 Smithtown, your appliances are currently losing 6% efficiency due to mineral buildup.
| Appliance | In Smithtown | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 8 yrs | 8.5 yrs | -6% |
| Washing Machine | 11.8 yrs | 12 yrs | -2% |
| Water Heater | 13.7 yrs | 15 yrs | -9% |
Regional Water Comparison
How Smithtown compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Smithtown, New York | 48 mg/L | 6.9 ppt | 🟢 Soft | reservoir |
| Hauppauge, New York | ≈ 120–179 mg/L | 1121.6 ppt | 🟠 Hard | groundwater |
| Nesconset, New York | 17 mg/L | 7.3 ppt | 🟢 Soft | reservoir |
| Saint James, New York | ≈ 120–179 mg/L | 5.3 ppt | 🟠 Hard | reservoir |
| Kings Park, New York | 36 mg/L | 0 ppt | 🟢 Soft | groundwater |
National Benchmark
How Smithtown compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Smithtown | 48 mg/L | 🟢 None |
| USA National Avg | 151 mg/L | 🟠 Moderate |
| Scarsdale Top Rated | 0.02 mg/L | 🟢 None |
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What Makes Smithtown's Water Unique?
Local geology and source profile
Smithtown Water District and St. James Water District serve the Town of Smithtown in Suffolk County, New York, primarily zip codes 11787 and 11788. Both utilities source supply from groundwater wells tapping the Upper Glacial and Magothy aquifers beneath Long Island. Treatment occurs at district facilities providing wellhead disinfection and corrosion control, with no surface water reservoirs or rivers involved. The system meets all EPA standards as detailed in the 2024 Drinking Water Quality Report.
The watershed encompasses recharge areas of central Suffolk County, where precipitation infiltrates sandy glacial outwash plains into the unconfined Upper Glacial aquifer and the semi-confined Magothy aquifer below. Geology features Pleistocene glacial sands and gravels overlying Cretaceous Raritan clays, with no significant carbonate rock formations such as limestone. This siliceous geology imparts a naturally soft water character — only 48 mg/L — as groundwater dissolves minimal hardness ions during recharge.
Soft water minimises scale buildup on fixtures, extending the life of water heaters, dishwashers, and washing machines without limescale interference. Soap and detergents lather efficiently, reducing usage, and no softening equipment is needed. Routine maintenance focuses on corrosion prevention, as low-mineral water can be slightly aggressive toward metal pipes; pH-balanced treatment helps mitigate this. The 2024 report confirms lead at 90th percentile ND (range ND–4.5 ppb) and copper at 0.26 ppm, with no PFAS exceedances and all contaminants within MCLs.
Geology & Source: Long Island Pleistocene glacial sands and gravels — Upper Glacial and Magothy aquifers over Cretaceous Raritan Formation; siliceous, carbonate-poor geology yields naturally soft water
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Frequently Asked Questions
Is Smithtown's water safe to drink?
Do I need a water softener in Smithtown?
How does Smithtown compare to the USA average?
Data Sources & Methodology
Water quality data for Smithtown 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.