Water hardness in DuPont
5 gpg moderately hard
Tap water in DuPont is moderately hard: 5 gpg (86 mg/L · 4.8 °dH · 8.6 °fH).
Source: City of DuPont 2025 Water Quality Report (2025) · data checked 2026-11-05
The only hardness figure in the City of DuPont's 2025 water quality report is 86.0 mg/L (5.0 gpg), from one sample at Hoffman Hill Well #2 taken on 7/18/2025. The city does not publish a citywide average, so other wells may differ. Treat it as a rough guide and check the latest report before sizing a softener.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 5 gpg |
|---|---|
| Utility | City of DuPont (PWS WA5320500) |
How DuPont compares
- Tap water in DuPont is 45 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 1079 of 1372 in the United States (1 = hardest); 21 % of these cities have softer water.
- In Washington it is number 8 of 27 cities; the regional median is 2.8 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 DuPont
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| 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 DuPont water hard or soft?
It is moderately hard: 86 mg/L as CaCO₃ (5 gpg, 4.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in DuPont 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 DuPont water?
5 gpg, equal to 4.8 °dH, 8.6 °fH or 86 mg/L calcium carbonate.
What dishwasher salt setting should I use in DuPont?
For 86 mg/L (4.8 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in DuPont?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: City of DuPont 2025 Water Quality Report (2025). Method: figure published by the water supplier. City of DuPont 2025 Water Quality Report · Outdated figure? Tell us