Water hardness in Rolla
14.5 gpg very hard
Tap water in Rolla is very hard: 14.5 gpg (249 mg/L · 13.9 °dH · 24.9 °fH).
Source: Rolla PWS 2025 Annual Water Quality Report (Missouri DNR) (2025) · data checked 2026-11-02
Rolla reports 249 mg/L in its 2025 annual water quality report filed with Missouri DNR (PWS MO3010700), which is very hard. The report gives a single figure and no range. Scale on heaters and fixtures is likely.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 14.5 gpg |
|---|---|
| Utility | City of Rolla Water (PWS MO3010700) |
How Rolla compares
- Tap water in Rolla is 61 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 378 of 1372 in the United States (1 = hardest); 72 % of these cities have softer water.
- In Missouri it is number 6 of 32 cities; the regional median is 10.3 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 Rolla
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 14 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| Hoover | S2 |
| 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 Rolla water hard or soft?
It is very hard: 249 mg/L as CaCO₃ (14.5 gpg, 13.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Rolla 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 Rolla water?
14.5 gpg, equal to 13.9 °dH, 24.9 °fH or 249 mg/L calcium carbonate.
What dishwasher salt setting should I use in Rolla?
For 249 mg/L (13.9 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Rolla?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Rolla PWS 2025 Annual Water Quality Report (Missouri DNR) (2025). Method: figure published by the water supplier. Rolla PWS 2025 Annual Water Quality Report (Missouri DNR) · Outdated figure? Tell us