How does Riverhead's water compare to the national average?

The USA national average is 151 mg/L. Riverhead (≈ 120–179 mg/L) is 1 mg/L softer than average.

Riverhead Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

groundwater

pH Level

6.2

neutral = 7.0

Lead

0.008 mg/L

✓ Below action level

TDS

95 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

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 Riverhead, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Riverhead	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 Riverhead compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Riverhead, New York	≈ 120–179 mg/L	15.7 ppt	🟠 Hard	groundwater
Hampton Bays, New York	≈ 120–179 mg/L	5.4 ppt	🟠 Hard	groundwater
Manorville, New York	≈ 120–179 mg/L	7.3 ppt	🟠 Hard	reservoir
Mastic, New York	≈ 120–179 mg/L	8.1 ppt	🟠 Hard	reservoir
Ridge, New York	≈ 180+ mg/L	7.8 ppt	🔴 Very Hard	groundwater

National Benchmark

How Riverhead compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Riverhead	≈ 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 Riverhead home

Shop water softeners on Amazon.com →

Shop Now

What Makes Riverhead's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 95 mg/LpH: 6.2

The Town of Riverhead Water Department provides drinking water to roughly 15,000 people across a 200-square-mile area on eastern Long Island in Suffolk County, New York. Their supply comes entirely from 12 groundwater wells that tap into the Upper Glacial and Magothy aquifers. Unlike many communities, Riverhead doesn't have surface water treatment plants; the well water goes straight into the distribution system after disinfection at the wellheads. This groundwater originates from the Long Island groundwater system.

The water's hardness comes from the local geology. The aquifers consist of loose sands, gravels, and clays deposited during the Pleistocene glacial period, sitting atop older Cretaceous sands and clays from the Raritan and Magothy Formations. Within these layers, you'll find limestone fragments and shell fragments that dissolve over time, releasing calcium and magnesium into the water supply.

Homeowners in Riverhead often notice limescale buildup, which can reduce the efficiency and lifespan of appliances like water heaters, dishwashers, and coffee makers. You might also see white deposits on faucets and showerheads, and it can take more soap to get things clean. To combat this, regularly descaling with vinegar and using high-efficiency detergents can help. For a more permanent solution to prevent scaling and improve cleaning, installing a whole-house water softener is recommended. The water typically has a pH between 7.0 and 8.0.

Geology & Source: Pleistocene glacial deposits and Cretaceous formations; unconsolidated sands, gravels, clays, limestone fragments, and shell fragments lead to hard water.

Other New York Water Reports

Hampton Bays

≈ 120–179 mg/L

🟠 Hard

Manorville

≈ 120–179 mg/L

🟠 Hard

Mastic

≈ 120–179 mg/L

🟠 Hard

Ridge

≈ 180+ mg/L

🔴 Very Hard

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 Riverhead's water safe to drink?

Yes. Riverhead's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Riverhead?

At ≈ 120–179 mg/L (Hard), Riverhead's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.

How does Riverhead compare to the USA average?

The USA national average is 151 mg/L. Riverhead (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Riverhead is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

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.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

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.

Measured

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.

Modelled

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.

Calculated

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.