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

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

Windham Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

groundwater

pH Level

7.3

neutral = 7.0

Lead

0.007 mg/L

✓ Below action level

TDS

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

Appliance	In Windham	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 Windham compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Windham, New Hampshire	≈ 120–179 mg/L	7.7 ppt	🟠 Hard	groundwater
Pelham, New Hampshire	≈ 0–60 mg/L	4.7 ppt	🟢 Soft	groundwater
Derry, New Hampshire	18 mg/L	12.8 ppt	🟢 Soft	reservoir
Derry Village, New Hampshire	≈ 120–179 mg/L	12.8 ppt	🟠 Hard	reservoir
Londonderry, New Hampshire	≈ 0–60 mg/L	6 ppt	🟢 Soft	groundwater

National Benchmark

How Windham compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Windham	≈ 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 Windham home

Shop water softeners on Amazon.com →

Shop Now

What Makes Windham's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 210 mg/LpH: 7.3

Pennichuck Water Works supplies roughly 3.5 million gallons daily to the Hardwood area of Windham, NH, drawing from groundwater. This supply comes from bedrock wells that tap into the local fractured aquifer. Treatment takes place at wellhead facilities, focusing on disinfection and corrosion control, with no surface water sources like reservoirs or rivers utilized. The Windham service area includes both residential and commercial zones, though private wells are more common outside the municipal service area.

The local geology is part of New Hampshire's Merrimack Belt, featuring Devonian Littleton Formation schists, Ordovician Clough Conglomerate, and igneous intrusions such as the Kinsman Quartz Monzonite. These crystalline rocks weather slowly, releasing minerals into the groundwater, particularly through fractures. This process results in a moderately mineralized and hard water supply, which can also pick up natural contaminants like arsenic and radon from the granitic bedrock.

This moderately hard water can lead to limescale buildup in appliances like water heaters, dishwashers, and coffee makers, potentially reducing their efficiency by 20-30% and increasing energy costs. You might notice laundry feels stiffer, and soap doesn't lather as well. Simple measures like regular vinegar descaling, installing low-flow fixtures, and flushing your water heater annually can help manage these effects. For homes experiencing persistent issues like spots on dishes or dry skin, especially given the variability common with well water, installing a water softener is a worthwhile consideration.

Geology & Source: Merrimack Belt igneous and metamorphic rocks; fractured schists, granites, and quartz monzonite yield hard water.

Other New Hampshire Water Reports

Pelham

≈ 0–60 mg/L

🟢 Soft

Derry

18 mg/L

🟢 Soft

Derry Village

≈ 120–179 mg/L

🟠 Hard

Londonderry

≈ 0–60 mg/L

🟢 Soft

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 Windham's water safe to drink?

Yes. Windham'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 Windham?

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

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