Water hardness in Oxnard
22.8 gpg very hard
Tap water in Oxnard is very hard: 22.8 gpg (390 mg/L · 21.8 °dH · 39 °fH).
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA5610007 (2026-07) · data checked 2026-10-19
Range across supply zones: 270–460 mg/L.
The Oxnard figure comes from State Water Resources Control Board lab results for the Oxnard Water Department. The median of 1,615 finished-water results from 2021 to 2026 is 390 mg/L as CaCO3 (22.8 gpg), with a range of 270.4 to 460 mg/L. That is very hard water. Scale builds fast on heaters and fixtures, and a softener is worth serious consideration.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 22.8 gpg |
|---|---|
| Utility | Oxnard Water Dept |
How Oxnard compares
- Tap water in Oxnard is 152 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 65 of 1372 in the United States (1 = hardest); 95 % of these cities have softer water.
- In California it is number 17 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Camarillo, 16 km away (4.4 gpg).
- Nearest city with clearly harder water: Santa Paula, 22 km away (32 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 Oxnard
| Brand | Setting for this water |
|---|---|
| Bosch | H06 |
| Miele | 22 °dH |
| AEG / Electrolux | 5 |
| Beko | 6th |
| Hoover | S3 |
| LG | H4 |
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 Oxnard water hard or soft?
It is very hard: 390 mg/L as CaCO₃ (22.8 gpg, 21.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Oxnard 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 Oxnard water?
22.8 gpg, equal to 21.8 °dH, 39 °fH or 390 mg/L calcium carbonate.
What dishwasher salt setting should I use in Oxnard?
For 390 mg/L (21.8 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Oxnard?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: California SWRCB Division of Drinking Water, EDT lab results, system CA5610007 (2026-07). Method: own measurement. California SWRCB Division of Drinking Water, EDT lab results, system CA5610007 · Outdated figure? Tell us