How hard is the water in Highland Park, NJ?

Tap water hardness
63mg/L
3.7gpg
Moderately hard

Reported by Highland Park W Dept · August 2025

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

Tap water in Highland Park has about 63 mg/L of hardness, which is 3.7 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Highland Park W Dept, dated August 2025.

Highland Park on the hardness scale, with nearby cities
060120180240300360+NJ typical 80New Brunswick: 66 mg/LNew Brunswick 66Milltown: 66 mg/LMilltown 66Sayreville: 66 mg/LSayreville 66Rutgers University-Busch Campus: 100 mg/LRutgers University-Busch Campus 100Middlesex: 100 mg/LMiddlesex 100South Plainfield: 102 mg/LSouth Plainfield 102Metuchen: 108 mg/LMetuchen 108Franklin Center: 111 mg/LFranklin Center 111Somerset: 169 mg/LSomerset 169East Franklin: 235 mg/LEast Franklin 235Highland Park 63mg/L as calcium carbonate060120180240300360+NJ 80New Brunswick: 66 mg/LNew Brunsw. 66Milltown: 66 mg/LMilltown 66Rutgers University-Busch Campus: 100 mg/LRutgers Un. 100Metuchen: 108 mg/LMetuchen 108Somerset: 169 mg/LSomerset 169East Franklin: 235 mg/LEast Frank. 23563 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 63 mg/L, Highland Park is 17 mg/L below the typical New Jersey figure of 80. None of the 10 nearest cities we track has softer water. The range nearby runs from 66 mg/L in New Brunswick to 235 in East Franklin.

What 63 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 Highland Park

3 people × 75 gallons a day × 3.7 gpg = 828 grains a day. A 24,000-grain unit regenerates about every 28 days.

Size it for your household

EPA record for Highland Park's water system

Highland Park W Dept · PWSID NJ1207001

1 health-based violation since 2016

Serves about 14,000 people from surface water.

Health-based
1
Monitoring or reporting
2
Open now
0
20162017201820192020202120222023202420252026Total trihalomethanes (TTHM)'16'18'20'22'24'26Total trihalomethanes (TTHM)
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Total trihalomethanes (TTHM)a disinfection byproduct12016Resolved

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 Highland Park water hard?

Somewhat. It measures about 63 mg/L (3.7 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Highland Park in grains per gallon?

About 3.7 gpg. One grain per gallon equals 17.1 mg/L, so 63 mg/L divided by 17.1 gives 3.7.

What size water softener do I need in Highland Park?

For 3 people using 75 gallons each per day, 3.7 gpg works out to about 828 grains a day. A 24,000-grain softener covers that with a regeneration about every 28 days.

Has the Highland Park water system had EPA violations?

EPA records show 1 health-based violation for Highland Park W Dept since 2016, involving Total trihalomethanes (TTHM). There were also 2 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, August 6, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.