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

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

Marlborough Water Hardness & Quality Report (2026)

Water Hardness

soft

~0–59 mg/L

Soft

estimated · not lab-verified

Source

reservoir

pH Level

7.3

neutral = 7.0

Lead

0.009 mg/L

✓ Below action level

TDS

341 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 Marlborough, your appliances are currently losing 4% efficiency due to mineral buildup.

Appliance	In Marlborough	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 Marlborough compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Marlborough, Massachusetts	≈ 0–59 mg/L	0 ppt	🟢 Soft	reservoir
Hudson, Massachusetts	101.5 mg/L	6 ppt	🟡 Moderately Hard	reservoir
Ashland, Massachusetts	≈ 120–179 mg/L	3.2 ppt	🟠 Hard	groundwater
Framingham Center, Massachusetts	≈ 0–60 mg/L	0 ppt	🟢 Soft	reservoir
Maynard, Massachusetts	≈ 0–60 mg/L	33.9 ppt	🟢 Soft	groundwater

National Benchmark

How Marlborough compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Marlborough	≈ 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 Marlborough's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 341 mg/LpH: 7.3

The Marlborough Department of Public Works Water Division serves approximately 38,499 residents in Marlborough, Middlesex County, Massachusetts. Water is sourced through purchases from the Massachusetts Water Resources Authority (MWRA), which draws from the Quabbin and Wachusett Reservoirs, as well as local Lake Williams and Millham Reservoir. Treatment employs chloramines, hypochlorite, ozone, and UV light for multi-barrier disinfection, with surface water as the primary type.

The Sudbury and Assabet River watersheds lie within a glacial drift landscape underlain by metamorphic bedrock from the Carboniferous Period, including schists and gneisses of the Marlboro Formation. Overlying unconsolidated sands and gravels deposited during the last Ice Age filter water through these formations, contributing very low dissolved mineral content. This geology yields characteristically soft water with minimal calcium and magnesium dissolution, though road salt and urban runoff can introduce ions like chloride in variable amounts.

Soft water in Marlborough means negligible scale buildup, sparing water heaters, dishwashers, and coffee makers from mineral deposits. Soap lathers easily and skin feels less dry post-shower. A water softener is not recommended and could over-mineralize the already low mineral levels, potentially corroding pipes. Water quality scores 80/100; however, two contaminants exceeded EPA health guidelines in past samples, including lead in some homes, and PFAS concerns exist — filtration is advised.

Geology & Source: Sudbury and Assabet River watersheds; glacial till and metamorphic bedrock — schists and gneisses of the Marlboro Formation (Carboniferous); Ice Age unconsolidated sands and gravels yield low mineral content — soft water

Other Massachusetts Water Reports

Hudson

101.5 mg/L

🟡 Moderately Hard

Ashland

≈ 120–179 mg/L

🟠 Hard

Framingham Center

≈ 0–60 mg/L

🟢 Soft

Maynard

≈ 0–60 mg/L

🟢 Soft

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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 Marlborough's water safe to drink?

Yes. Marlborough'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 Marlborough?

Marlborough'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 Marlborough compare to the USA average?

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