Water hardness in Rahway
4.4 gpg moderately hard
Tap water in Rahway is moderately hard: 4.4 gpg (75 mg/L · 4.2 °dH · 7.5 °fH).
Source: Rahway 2023 Annual Drinking Water Quality Report (Veolia) (2023) · data checked 2026-11-02
Rahway is served by Veolia Water New Jersey through the Rahway system. The 2023 annual report lists hardness of 75 mg/L as CaCO₃, in the moderate band. A single value is given, so seasonal changes are not shown. Some spotting on glassware is possible, but heavy scale is unlikely.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 4.4 gpg |
|---|---|
| Utility | Veolia Water New Jersey (Rahway System) |
How Rahway compares
- Tap water in Rahway is 52 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1127 of 1372 in the United States (1 = hardest); 18 % of these cities have softer water.
- In New Jersey it is number 31 of 34 cities; the regional median is 6.4 gpg.
Ranking of the hardest and softest water in the United States →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Rahway
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 4 °dH |
| AEG / Electrolux | 2 |
| Beko | 1st |
| Hoover | S1 |
| LG | H1 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Rahway water hard or soft?
It is moderately hard: 75 mg/L as CaCO₃ (4.4 gpg, 4.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Rahway safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Rahway water?
4.4 gpg, equal to 4.2 °dH, 7.5 °fH or 75 mg/L calcium carbonate.
What dishwasher salt setting should I use in Rahway?
For 75 mg/L (4.2 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Rahway?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Rahway 2023 Annual Drinking Water Quality Report (Veolia) (2023). Method: figure published by the water supplier. Rahway 2023 Annual Drinking Water Quality Report (Veolia) · Outdated figure? Tell us