Hard water in Summit, NJ
Reported by NJ American Water - Short Hills · October 2025
- NJ typical
- 80 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
Tap water in Summit has about 133 mg/L of hardness, which is 7.8 grains per gallon. On the USGS scale that counts as hard. The number comes from NJ American Water - Short Hills, dated October 2025.
Summit sits 53 mg/L above the typical New Jersey figure of 80. Of the 10 nearest cities we track, 6 have softer water and 2 have harder. The range nearby runs from 100 mg/L in Mountainside to 138 in Madison.
What 133 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 133 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.
3 people × 75 gallons a day × 7.8 gpg = 1,750 grains a day. A 24,000-grain unit regenerates about every 13 days.
EPA record for Summit's water system
No health-based violations since 2016
Serves about 217,230 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 1
- Open now
- 0
TapWaterData ties Summit to this system. EPA's service-area records do not name Summit, so check the utility printed on your water bill.
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 Summit water hard?
Yes. It measures about 133 mg/L (7.8 grains per gallon), which the USGS classes as hard.
What is the water hardness in Summit in grains per gallon?
About 7.8 gpg. One grain per gallon equals 17.1 mg/L, so 133 mg/L divided by 17.1 gives 7.8.
What size water softener do I need in Summit?
For 3 people using 75 gallons each per day, 7.8 gpg works out to about 1,750 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.
Has the Summit water system had EPA violations?
EPA records show no health-based violations for NJ American Water - Short Hills since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- Chatham105 mg/LModerately hard
- Mountainside100 mg/LModerately hard
- New Providence133 mg/LHard
- Short Hills133 mg/LHard
- Madison138 mg/LHard
- Vauxhall109 mg/LModerately hard
- Florham Park137 mg/LHard
- Westfield100 mg/LModerately hard
- Kenilworth100 mg/LModerately hard
- Garwood100 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, October 8, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.