Water Hardness in Onset, MA

Q: Do I need a water softener in Onset, MA?

At a citywide weighted average of 30 PPM, Onset has relatively soft water. A water softener is generally not necessary.

Q: How many water systems serve Onset, MA?

Onset, Massachusetts has 35 matched water systems across 2 zip codes.

Massachusetts · 2 zip codes · 35 matched water systems

25 PPM

1.5 GPG

Soft

0Soft60120180300+

Verified — Annual Water Quality Report

City avg (weighted): 30 PPM

Dataset updated March 9, 202635 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology

System used for this reading

Brockton Water Department

MA4044000

Water source: surface water

Serves: 105,643

USGS environmental estimate: 35 PPM

Source context

How this city reading is built

This city reading is a weighted rollup across 35 matched water systems and 2 ZIP codes. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.

Source basis

17 verified treated-water sources

35 matched systems total for this city; treated-water reports are prioritized when available.

Water source profile

Primarily groundwater

Groundwater commonly picks up calcium and magnesium after contact with rock and soil. This profile is weighted by known population served across matched systems.

Data recency

March 9, 2026

Dataset rebuilt March 9, 2026; individual utility reporting years can vary.

Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.

Water Systems in Onset

These systems are matched to Onset, MA. Citywide readings are useful for comparison, but the system serving a specific address may differ from the city average.

35 water systems

PWSID is the public water system identifier. Data Source shows whether the hardness value comes from a treated-water report, USGS monitoring, or a local estimate; source year is shown when available.

Water System	Source	Hardness	Pop. Served	Data Source
Brockton Water Department MA4044000	surface water	25 PPM Soft USGS estimate: 35 PPM	105,643	Verified — Annual Water Quality Report
Falmouth Water Dept MA4096000	surface water	37 PPM Soft	97,551	Estimated — Nearby Data
Dennis Water District MA4075000	groundwater	46 PPM Soft	65,000	Estimated — Nearby Data
Upper Cape Regional Water Cooperative MA4261024	groundwater	17 PPM Soft	56,250	Estimated — Nearby Data
Centerville Osterville Marstons Mills Wd MA4020002	groundwater	33 PPM Soft	50,000	Estimated — Nearby Data

Brockton Water Department

MA4044000

Soft

25 PPMsurface water105,643 servedVerified — Annual Water Quality Report

Source water: 35 PPM

Falmouth Water Dept

MA4096000

Soft

37 PPMsurface water97,551 servedEstimated — Nearby Data

Dennis Water District

MA4075000

Soft

46 PPMgroundwater65,000 servedEstimated — Nearby Data

Upper Cape Regional Water Cooperative

MA4261024

Soft

17 PPMgroundwater56,250 servedEstimated — Nearby Data

Centerville Osterville Marstons Mills Wd

MA4020002

Soft

33 PPMgroundwater50,000 servedEstimated — Nearby Data

Showing the first 5 systems. Expand to review all matched systems.

Zip Codes in Onset, MA

0253236 0255825

What This Means For You

Recommendations are based on the displayed hardness reading. Confirm your tap reading before sizing or buying treatment equipment.

Your Water Is Soft

Your water hardness is in the soft range. You likely don't need a water softener. Enjoy your naturally soft water!

Know your water hardness?

If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Onset, MA.

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Frequently Asked Questions

How hard is the water in Onset, MA?

The citywide weighted average water hardness in Onset, MA is 30 PPM (1.8 GPG), classified as soft. This is based on 35 matched water systems. The gauge highlights Brockton Water Department, a verified treated-water system, because individual systems can differ from the citywide average.

Do I need a water softener in Onset, MA?

At 30 PPM, the citywide average is relatively soft. A water softener is generally not necessary.

Is hard water in Onset, MA safe to drink?

Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.

How many water systems serve Onset, MA?

Onset, Massachusetts is served by 35 matched water systems across 2 zip codes.

Learn More About Your Water

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