Water hardness in Mesa
16 gpg very hard
Tap water in Mesa is very hard: 16 gpg (274 mg/L · 15.3 °dH · 27.4 °fH).
Source: City of Mesa 2025 Consumer Confidence Report (2025) · data checked 2026-10-19
Range across supply zones: 205–274 mg/L.
3 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| City Zone | 12 | 205 | very hard |
| Eastern Zone | 16 | 274 | very hard |
| Southern Zone | 16 | 274 | very hard |
Mesa's 2025 report gives different averages by zone: about 12 gpg in the City Zone and 16 gpg in the Eastern and Southern zones. The page shows the median of 273.9 mg/L (16.0 gpg). The report gives these as approximate zone averages. The supply is Salt and Verde river water, and an ion-exchange softener is the usual fix for scale.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 16 gpg |
|---|---|
| Utility | City of Mesa Water Resources |
How Mesa compares
- Tap water in Mesa is 77 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 319 of 1372 in the United States (1 = hardest); 77 % of these cities have softer water.
- In Arizona it is number 1 of 12 cities; the regional median is 13 gpg.
- Nearest city with clearly softer water: Queen Creek, 26 km away (12 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 Mesa
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 4 |
| 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 Mesa water hard or soft?
It is very hard: 274 mg/L as CaCO₃ (16 gpg, 15.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Mesa 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 Mesa water?
16 gpg, equal to 15.3 °dH, 27.4 °fH or 274 mg/L calcium carbonate.
What dishwasher salt setting should I use in Mesa?
For 274 mg/L (15.3 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Mesa?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: City of Mesa 2025 Consumer Confidence Report (2025). Method: figure published by the water supplier. City of Mesa 2025 Consumer Confidence Report · Outdated figure? Tell us