Hard water in Somerset, NJ
Reported by Franklin Township Dept of Public Works · July 2025
- NJ typical
- 80 mg/L
- EPA health violations since 2016
- 2
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in Somerset carries roughly 169 mg/L of dissolved calcium and magnesium, or 9.9 grains per gallon. That is hard water. The number comes from Franklin Township Dept of Public Works, dated July 2025.
At 169 mg/L, Somerset is 89 mg/L above the typical New Jersey figure of 80. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 63 mg/L in Highland Park to 235 in East Franklin.
What 169 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 169 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 × 9.9 gpg = 2,228 grains a day. A 24,000-grain unit regenerates about every 10 days.
EPA record for Somerset's water system
2 health-based violations since 2016
Serves about 57,150 people from surface water.
- Health-based
- 2
- Monitoring or reporting
- 32
- Open now
- 3
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Lead and Copper Rulecorrosion control and lead sampling | 2 | 2021 | Resolved |
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 Somerset water hard?
Yes. It measures about 169 mg/L (9.9 grains per gallon), which the USGS classes as hard.
What is the water hardness in Somerset in grains per gallon?
About 9.9 gpg. One grain per gallon equals 17.1 mg/L, so 169 mg/L divided by 17.1 gives 9.9.
What size water softener do I need in Somerset?
For 3 people using 75 gallons each per day, 9.9 gpg works out to about 2,228 grains a day. A 24,000-grain softener covers that with a regeneration about every 10 days.
Has the Somerset water system had EPA violations?
EPA records show 2 health-based violations for Franklin Township Dept of Public Works since 2016, involving Lead and Copper Rule. There were also 32 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- East Franklin235 mg/LVery hard
- Rutgers University-Busch Campus100 mg/LModerately hard
- Franklin Center111 mg/LModerately hard
- New Brunswick66 mg/LModerately hard
- Highland Park63 mg/LModerately hard
- Bound Brook100 mg/LModerately hard
- Middlesex100 mg/LModerately hard
- Franklin Park235 mg/LVery hard
- Manville100 mg/LModerately hard
- Milltown66 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, July 31, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.