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

The USA national average is 151 mg/L. Durham (≈ 0–59 mg/L) is 121 mg/L softer than average.

Durham Water Hardness & Quality Report (2026)

Water Hardness

soft

~0–59 mg/L

Soft

estimated · not lab-verified

Source

reservoir

pH Level

8.1

neutral = 7.0

Lead

0.002 mg/L

✓ Below action level

TDS

213 mg/L

Est. Daily Cost

$0.08

energy & soap waste

Source: See methodology section below · Updated 2026

soft~0–59 mg/LSoft · 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 Durham, your appliances are currently losing 4% efficiency due to mineral buildup.

Appliance	In Durham	Soft Water City	Efficiency Loss
Kettle	8.2 yrs	8.5 yrs	-4%
Washing Machine	11.5 yrs	12 yrs	-4%
Water Heater	14.4 yrs	15 yrs	-4%

Regional Water Comparison

How Durham compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Durham, New Hampshire	≈ 0–59 mg/L	0 ppt	🟢 Soft	reservoir
Dover, New Hampshire	≈ 0–60 mg/L	0 ppt	🟢 Soft	groundwater
Somersworth, New Hampshire	≈ 0–60 mg/L	0 ppt	🟢 Soft	reservoir
Rochester, New Hampshire	≈ 0–60 mg/L	0 ppt	🟢 Soft	reservoir
Portsmouth, New Hampshire	≈ 0–60 mg/L	140 ppt	🟢 Soft	reservoir

National Benchmark

How Durham compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Durham	≈ 0–59 mg/L	🟢 None
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Durham's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 213 mg/LpH: 8.1

The UNH-Durham Water System is a public water utility jointly operated by the University of New Hampshire and the Town of Durham Public Works Department. Serving about 16,000 residents in Durham, New Hampshire, the system draws from combined surface water sources. These sources are treated at facilities located at 28 Waterworks Road. The utility covers Strafford County in New Hampshire's seacoast region. The water originates in the New England Uplands, an area characterized by Precambrian metamorphic bedrock like gneiss and schist, covered by glacial till and stratified drift. This crystalline bedrock terrain, with its limited carbonate minerals, results in naturally soft water, typical for the region.

Homeowners in Durham will find that the naturally soft water means fewer issues with scale buildup in appliances and less soap scum. You'll likely use less detergent and soap compared to areas with hard water. Appliances like water heaters, dishwashers, and washing machines should run efficiently without the need for extra softening equipment. While soft water generally means a lack of hardness-related problems, the primary concern for plumbing can be corrosion. However, the UNH-Durham Water System addresses this through pH adjustment and disinfection during its treatment process, which includes filtration and sodium hypochlorite disinfection. The system consistently meets EPA standards, achieving a perfect quality score with no reported violations, and no known health risks are associated with its soft character.

Geology & Source: New England Uplands metamorphic terrain; gneiss and schist produce naturally soft water

Other New Hampshire Water Reports

Dover

≈ 0–60 mg/L

🟢 Soft

Somersworth

≈ 0–60 mg/L

🟢 Soft

Rochester

≈ 0–60 mg/L

🟢 Soft

Portsmouth

≈ 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 Durham's water safe to drink?

Yes. Durham's water meets all federal safety standards. The hardness is ≈ 0–59 mg/L (Soft), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Durham?

Durham's water is soft at ≈ 0–59 mg/L. A water softener is generally not necessary, though a carbon filter can improve taste and remove any remaining chlorine.

How does Durham compare to the USA average?

The USA national average is 151 mg/L. Durham (≈ 0–59 mg/L) is 121 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 Durham 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.