Water hardness in Oro Valley
8.9 gpg hard
Tap water in Oro Valley is hard: 8.9 gpg (153 mg/L · 8.6 °dH · 15.3 °fH).
Source: Oro Valley Water Utility - Water Quality page (2026) · data checked 2026-11-02
Range across supply zones: 36–270 mg/L.
Oro Valley Water Utility publishes hardness values from 36 to 270 mg/L, and we compute a median of 153 mg/L (page updated 2026). The spread is wide, which usually points to different supply sources or wells across the service area. We have not confirmed the mix, so check the utility's page for your neighborhood.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 8.9 gpg |
|---|---|
| Utility | Oro Valley Water Utility |
How Oro Valley compares
- Tap water in Oro Valley is close to the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 699 of 1372 in the United States (1 = hardest); 49 % of these cities have softer water.
- In Arizona it is number 10 of 12 cities; the regional median is 13 gpg.
Ranking of the hardest and softest water in the United States →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Oro Valley
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 9 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| LG | H2 |
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 Oro Valley water hard or soft?
It is hard: 153 mg/L as CaCO₃ (8.9 gpg, 8.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Oro Valley 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 Oro Valley water?
8.9 gpg, equal to 8.6 °dH, 15.3 °fH or 153 mg/L calcium carbonate.
What dishwasher salt setting should I use in Oro Valley?
For 153 mg/L (8.6 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Oro Valley?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Oro Valley Water Utility - Water Quality page (2026). Method: computed from supplier's calcium and magnesium. Oro Valley Water Utility - Water Quality page · Outdated figure? Tell us