How hard is the water in Middlesex, NJ?

Tap water hardness
100mg/L
5.8gpg
Moderately hard

Reported by NJ American Water - Raritan · October 2025

NJ typical
80 mg/L
EPA health violations since 2016
1
Softener for 3 people
24k grain
Data
Utility report

Middlesex water measures 100 mg/L (5.8 gpg) of hardness, moderately hard by USGS standards. The number comes from NJ American Water - Raritan, dated October 2025.

Middlesex on the hardness scale, with nearby cities
060120180240300360+NJ typical 80Dunellen: 100 mg/LDunellen 100Bound Brook: 100 mg/LBound Brook 100Finderne: 100 mg/LFinderne 100Rutgers University-Busch Campus: 100 mg/LRutgers University-Busch Campus 100North Plainfield: 100 mg/LNorth Plainfield 100Martinsville: 100 mg/LMartinsville 100Plainfield: 100 mg/LPlainfield 100South Plainfield: 102 mg/LSouth Plainfield 102Franklin Center: 111 mg/LFranklin Center 111Somerset: 169 mg/LSomerset 169Middlesex 100mg/L as calcium carbonate060120180240300360+NJ 80Dunellen: 100 mg/LDunellen 100Bound Brook: 100 mg/LBound Brook 100Finderne: 100 mg/LFinderne 100Rutgers University-Busch Campus: 100 mg/LRutgers Un. 100South Plainfield: 102 mg/LSouth Plai. 102Franklin Center: 111 mg/LFranklin C. 111100 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 100 mg/L, Middlesex is 20 mg/L above the typical New Jersey figure of 80. None of the 10 nearest cities we track has softer water. The range nearby runs from 100 mg/L in Dunellen to 169 in Somerset.

What 100 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

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

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Middlesex

3 people × 75 gallons a day × 5.8 gpg = 1,316 grains a day. A 24,000-grain unit regenerates about every 18 days.

Size it for your household

EPA record for Middlesex's water system

Middlesex Water Company · PWSID NJ1225001

1 health-based violation since 2016

Serves about 233,376 people from surface water.

Health-based
1
Monitoring or reporting
9
Open now
0

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

20162017201820192020202120222023202420252026Lead and Copper Rule'16'18'20'22'24'26Lead and Copper Rule
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Lead and Copper Rulecorrosion control and lead sampling12019Resolved

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 Middlesex water hard?

Somewhat. It measures about 100 mg/L (5.8 grains per gallon), which the USGS classes as moderately hard.

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

About 5.8 gpg. One grain per gallon equals 17.1 mg/L, so 100 mg/L divided by 17.1 gives 5.8.

What size water softener do I need in Middlesex?

For 3 people using 75 gallons each per day, 5.8 gpg works out to about 1,316 grains a day. A 24,000-grain softener covers that with a regeneration about every 18 days.

Has the Middlesex water system had EPA violations?

EPA records show 1 health-based violation for Middlesex Water Company since 2016, involving Lead and Copper Rule. There were also 9 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 6, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.