Hard water in Madison, NJ

Tap water hardness
138mg/L
8.1gpg
Hard

Reported by Southeast Morris County MUA · October 2025

NJ typical
80 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

Madison water measures 138 mg/L (8.1 gpg) of hardness, hard by USGS standards. The number comes from Southeast Morris County MUA, dated October 2025.

Madison on the hardness scale, with nearby cities
060120180240300360+NJ typical 80Mountainside: 100 mg/LMountainside 100Chatham: 105 mg/LChatham 105Summit: 133 mg/LSummit 133New Providence: 133 mg/LNew Providence 133Short Hills: 133 mg/LShort Hills 133Florham Park: 137 mg/LFlorham Park 137Morristown: 148 mg/LMorristown 148Whippany: 148 mg/LWhippany 148Morris Plains: 148 mg/LMorris Plains 148Troy Hills: 208 mg/LTroy Hills 208Madison 138mg/L as calcium carbonate060120180240300360+NJ 80Chatham: 105 mg/LChatham 105Summit: 133 mg/LSummit 133New Providence: 133 mg/LNew Provid. 133Florham Park: 137 mg/LFlorham Pa. 137Morristown: 148 mg/LMorristown 148Whippany: 148 mg/LWhippany 148138 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Madison sits 58 mg/L above the typical New Jersey figure of 80. Of the 10 nearest cities we track, 6 have softer water and 4 have harder. The range nearby runs from 100 mg/L in Mountainside to 208 in Troy Hills.

What 138 mg/L means at home

Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.

Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.

Soap and detergent need a little more to lather, and soap scum shows up in the tub.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

At 138 mg/L most of the trouble is scale, and only a few things deal with it.

Ion-exchange water softener

The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.

Salt-free conditioner

No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.

Reverse osmosis or carbon filter

Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.

Softener size for Madison

3 people × 75 gallons a day × 8.1 gpg = 1,818 grains a day. A 24,000-grain unit regenerates about every 13 days.

Size it for your household

EPA record for Madison's water system

Madison Water Dept · PWSID NJ1417001

No health-based violations since 2016

Serves about 15,820 people from groundwater.

Health-based
0
Monitoring or reporting
12
Open now
2

EPA lists Madison Water Dept as the system serving Madison. The hardness figure above comes from a different system's report, which TapWaterData uses for Madison.

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Madison water hard?

Yes. It measures about 138 mg/L (8.1 grains per gallon), which the USGS classes as hard.

What is the water hardness in Madison in grains per gallon?

About 8.1 gpg. One grain per gallon equals 17.1 mg/L, so 138 mg/L divided by 17.1 gives 8.1.

What size water softener do I need in Madison?

For 3 people using 75 gallons each per day, 8.1 gpg works out to about 1,818 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.

Has the Madison water system had EPA violations?

EPA records show no health-based violations for Madison Water Dept since 2016. There were also 12 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 227 cities in New Jersey

Hardness data: TapWaterData US Water Hardness (utility report, October 4, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.