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Chelmsford Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

groundwater

pH Level

7.5

neutral = 7.0

Lead

0.009 mg/L

✓ Below action level

TDS

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

ApplianceIn ChelmsfordSoft Water CityEfficiency 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 Chelmsford compares to its nearest neighbours

CityHardnessPFAS (ppt)RiskSource
Chelmsford, Massachusetts≈ 120–179 mg/L124.6 ppt🟠 Hardgroundwater
Lowell, Massachusetts≈ 0–60 mg/L12.5 ppt🟢 Softreservoir
Westford, Massachusetts81.5 mg/L77.5 ppt🟡 Moderately Hardmixed
Tyngsboro, Massachusetts≈ 0–60 mg/L14.3 ppt🟢 Softreservoir
Dracut, Massachusetts≈ 0–60 mg/L39.4 ppt🟢 Softreservoir

National Benchmark

How Chelmsford compares to the USA average

BenchmarkHardnessAppliance Risk
Chelmsford≈ 120–179 mg/L🟠 Moderate
USA National Avg151 mg/L🟠 Moderate
Scarsdale Top Rated0.02 mg/L🟢 None

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What Makes Chelmsford's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 243 mg/LpH: 7.5

The Chelmsford Water District serves approximately 35,000 residents across 23 square miles in Middlesex County, Massachusetts. Water is sourced from 20 groundwater wells, including the Bomil Well Field with four gravel-packed wells and two bedrock wells in the Merrimack River Basin, recharged by Cold Spring Brook and Stony Brook. Treatment at the main plant on Watershed Lane involves air stripping, filtration, and disinfection with hypochlorite before distribution.

The supply originates within the Merrimack River watershed, where glacial deposits of sand, gravel, and till overlie fractured bedrock of the Merrimack Belt, including Devonian schists, quartzites, and igneous intrusions. Natural leaching of alkaline earth minerals from glacial limestone erratics and bedrock weathering imparts a hard character to the groundwater. This mineralized, post-glacial aquifer system yields water typical of New England valley fills, with subsurface rock-water interactions dominating the water chemistry.

Hard water leads to scale buildup in pipes, water heaters, dishwashers, washing machines, and coffee makers, where mineral deposits insulate heating elements and clog valves. Maintenance tips include installing sediment pre-filters, flushing water heaters annually, and using vinegar soaks for faucets. A water softener is recommended for households experiencing soap scum, dry skin, or appliance issues. The district reports 6 contaminants above EPA health-based guidelines, with treatment via air stripping, filtration, and hypochlorite disinfection ensuring compliance; annual Consumer Confidence Reports detail full monitoring results.

Geology & Source: Merrimack River Basin — glacial till and stratified drift aquifer over Devonian Merrimack Belt schists, quartzites, and granites; calcium and magnesium leaching from glacial limestone erratics and fractured bedrock produces hard water

Other Massachusetts Water Reports

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Frequently Asked Questions

Is Chelmsford's water safe to drink?
Yes. Chelmsford'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 Chelmsford?
At ≈ 120–179 mg/L (Hard), Chelmsford'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 Chelmsford compare to the USA average?
The USA national average is 151 mg/L. Chelmsford (≈ 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 Chelmsford 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

pH

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.