Water hardness in Platteville
18.8 gpg very hard
Tap water in Platteville is very hard: 18.8 gpg (322 mg/L · 18 °dH · 32.2 °fH).
Source: Wisconsin DNR Drinking Water System portal (Platteville Waterworks) (2026) · data checked 2026-10-20
Range across supply zones: 321–326 mg/L.
Platteville, Wisconsin, is supplied by Platteville Waterworks. The Wisconsin DNR portal lists 322 mg/L as CaCO₃, within a narrow range of 321 to 326 mg/L. That is very hard water, and it appears stable across the reported samples. Scale on water heaters and kettles is the usual result.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 18.8 gpg |
|---|---|
| Utility | Platteville Waterworks |
How Platteville compares
- Tap water in Platteville is 108 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 187 of 1372 in the United States (1 = hardest); 86 % of these cities have softer water.
- In Wisconsin it is number 109 of 448 cities; the regional median is 14.3 gpg.
- Nearest city with clearly softer water: Dubuque, 30 km away (5.8 gpg).
- Nearest city with clearly harder water: Benton, 19 km away (25.7 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Platteville
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 18 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| LG | H3 |
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 Platteville water hard or soft?
It is very hard: 322 mg/L as CaCO₃ (18.8 gpg, 18 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Platteville 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 Platteville water?
18.8 gpg, equal to 18 °dH, 32.2 °fH or 322 mg/L calcium carbonate.
What dishwasher salt setting should I use in Platteville?
For 322 mg/L (18 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Platteville?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Wisconsin DNR Drinking Water System portal (Platteville Waterworks) (2026). Method: figure published by the water supplier. Wisconsin DNR Drinking Water System portal (Platteville Waterworks) · Outdated figure? Tell us