Setauket-East Setauket Water Hardness & Quality Report (2026)
Water Hardness
6.9 grains per gallon
Source
reservoir
pH Level
7.8
neutral = 7.0
Lead
0.005 mg/L
✓ Below action level
TDS
243.1 mg/L
Est. Daily Cost
$0.31
energy & soap waste
Source: USGS Water Quality Portal · 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 Setauket-East Setauket, your appliances are currently losing 16% efficiency due to mineral buildup.
| Appliance | In Setauket-East Setauket | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 5.7 yrs | 8.5 yrs | -33% |
| Washing Machine | 9.2 yrs | 12 yrs | -23% |
| Water Heater | 10.9 yrs | 15 yrs | -27% |
Regional Water Comparison
How Setauket-East Setauket compares to its nearest neighbours
| City | Hardness | PFAS (ppt) | Risk | Source |
|---|---|---|---|---|
| ▶ Setauket-East Setauket, New York | 118 mg/L | 5.7 ppt | 🟡 Moderately Hard | reservoir |
| East Setauket, New York | 177 mg/L | 8.4 ppt | 🟠 Hard | reservoir |
| Stony Brook, New York | 87.5 mg/L | 4.3 ppt | 🟡 Moderately Hard | reservoir |
| Centereach, New York | 112.5 mg/L | 5.4 ppt | 🟡 Moderately Hard | reservoir |
| Saint James, New York | 109.5 mg/L | 5.3 ppt | 🟡 Moderately Hard | reservoir |
National Benchmark
How Setauket-East Setauket compares to the USA average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Setauket-East Setauket | 118 mg/L | 🟡 Low |
| USA National Avg | 150 mg/L | 🟠 Moderate |
| Badger Top Rated | 8.5 mg/L | 🟢 None |
Bring Badger-quality water to your Setauket-East Setauket home
Shop water softeners on Amazon.com →
What Makes Setauket-East Setauket's Water Unique?
Local geology and source profile
Setauket-East Setauket, New York, in Suffolk County — a Suffolk County community adjacent to Stony Brook and Port Jefferson on the north shore of Long Island — receives its water from the Suffolk County Water Authority (SCWA) or local Three Village water districts, drawing from the Long Island Aquifer (Magothy-Ronkonkoma aquifer, north-central Suffolk County) through the north Long Island distribution.
The moderately hard 118 mg/L hardness and TDS of 243.1 mg/L are consistent with the north-central Suffolk SCWA communities — between the central Suffolk (Farmingville: 101 mg/L) and east-central Suffolk (Mastic: 169.5 mg/L) hardness values, reflecting the Setauket area's moderate Magothy aquifer calcareous zone. The Long Island Aquifer (Magothy) at north-central Suffolk is developed in Cretaceous Magothy Formation (calcareous sand — moderate carbonate content), Pleistocene Ronkonkoma outwash (slightly calcareous), and upper Cretaceous Lloyd formation (slightly calcareous).
At 118 mg/L, Setauket-East Setauket's water is moderately hard — scale builds in kettles and appliances over months, dishwashers benefit from rinse aid, and faucet aerators need periodic cleaning. Quarterly descaling is appropriate. The PFAS level of 5.7 ppt warrants a certified drinking water filter — Stony Brook University and the Brookhaven National Laboratory (Suffolk County — PFAS legacy), and the Long Island north shore PFAS background from the Grumman-Bethpage complex contribute to Setauket's readings.
Geology & Source: Setauket-East Setauket in Suffolk County draws from the Suffolk County Water Authority on the Long Island Aquifer (Suffolk County, north-central Long Island) — the Long Island Aquifer at north-central Suffolk is developed in Pleistocene Ronkonkoma Aquifer sand and Cretaceous Magothy Formation (calcareous) — New York Suffolk County Long Island Aquifer system produces moderately hard water at 118 mg/L with TDS 243.1 mg/L.