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

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

Brentwood Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

neutral = 7.0

Lead

0.006 mg/L

✓ Below action level

TDS

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

Appliance	In Brentwood	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 Brentwood compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Brentwood, New York	≈ 120–179 mg/L	6.7 ppt	🟠 Hard	reservoir
North Bay Shore, New York	174 mg/L	8.3 ppt	🟠 Hard	reservoir
Central Islip, New York	≈ 0–60 mg/L	5.5 ppt	🟢 Soft	reservoir
Bay Shore, New York	≈ 120–179 mg/L	8.1 ppt	🟠 Hard	reservoir
Hauppauge, New York	≈ 120–179 mg/L	1121.6 ppt	🟠 Hard	groundwater

National Benchmark

How Brentwood compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Brentwood	≈ 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 Brentwood home

Shop water softeners on Amazon.com →

Shop Now

What Makes Brentwood's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 98 mg/LpH: 6

The Suffolk County Water Authority (SCWA) is the primary utility serving Brentwood, New York, in Suffolk County on Long Island, supplying over 500,000 customers across the county. Brentwood's water comes exclusively from groundwater — local wells in the Upper Glacial and Magothy aquifers drawn from more than 70 well fields. There are no surface water treatment plants; treatment is focused on disinfection and corrosion control at well stations, serving residential, commercial, and industrial areas in Brentwood and surrounding communities.

Brentwood's supply relies on the Long Island aquifer system, with the Upper Glacial aquifer comprising Pleistocene glacial outwash sands and gravels, and the underlying Magothy aquifer consisting of Cretaceous sands and clays. These unconsolidated formations overlie Raritan Formation clays. Glacial deposits incorporate carbonate-rich limestone and dolomite fragments from upstate sources, and shell beds in the coastal plain geology contribute soluble calcite, imparting a hard, mineralized character typical of Long Island's sedimentary aquifer system.

Hard water in Suffolk County leads to significant limescale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and lifespan. Appliances like coffee makers and faucets develop white deposits, increasing energy costs by up to 30% due to scale insulation. Regular vinegar descaling and installing scale-inhibiting filters are recommended. A water softener is highly recommended to prevent damage and extend appliance life; SCWA meets lead and copper rules via orthophosphate corrosion inhibitors and uses granular activated carbon (GAC) treatment at wells with PFAS detections.

Geology & Source: Long Island aquifer system — Upper Glacial aquifer (Pleistocene glacial outwash sands/gravels) and Magothy aquifer (Cretaceous sands/clays); limestone, dolomite fragments and shell carbonates in glacial till produce hard water

Other New York Water Reports

North Bay Shore

174 mg/L

🟠 Hard

Central Islip

≈ 0–60 mg/L

🟢 Soft

Bay Shore

≈ 120–179 mg/L

🟠 Hard

Hauppauge

≈ 120–179 mg/L

🟠 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 Brentwood's water safe to drink?

Yes. Brentwood'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 Brentwood?

At ≈ 120–179 mg/L (Hard), Brentwood'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 Brentwood compare to the USA average?

The USA national average is 151 mg/L. Brentwood (≈ 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 Brentwood 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.