TapWaterGuide
Worldwide water safety reference
Safe California, United States · Last reviewed:

Is Tap Water Safe to Drink in Oxnard?

Yes, tap water in Oxnard is safe to drink. The city blends imported state water with local groundwater that historically ran salty and nitrate-affected, and its GREAT reverse-osmosis program has markedly improved both quality and taste. Served water meets all standards.

Hardness
Hard
pH
7.3–8.0
TDS
400–700 mg/L
EPA Status
Compliant
Soft
Moderate
Hard
Very Hard

Water Source

The City of Oxnard blends imported State Water Project water delivered through the Calleguas Municipal Water District with local Oxnard Plain groundwater from United Water Conservation District facilities and city wells, polished by reverse osmosis at the city's GREAT program desalter.

EPA Compliance Status

Meets all federal Safe Drinking Water Act standards and California limits.

Notable Contaminants & Context

  • High natural salinity and total dissolved solids in Oxnard Plain groundwater — worsened historically by seawater intrusion from decades of agricultural overpumping — are reduced by blending and reverse osmosis
  • Nitrate from the plain's long farming history affects parts of the aquifer and is blended or treated below limits
  • Disinfection byproducts are monitored and kept within limits

Water Quality Data

Key contaminants detected vs. regulatory limits. All values from the most recent published report — Source: City of Oxnard Water Division 2024 CCR.

Contaminant Detected Limit Status
Chlorine (total) 1.0 mg/L 4.0 mg/L
Fluoride 0.7 mg/L 4.0 mg/L
Lead (90th percentile) 1.9 µg/L 15.0 µg/L
Nitrate (as N) 3.4 mg/L 10.0 mg/L
TTHM (Total Trihalomethanes) 18.2 µg/L 80.0 µg/L
HAA5 (Haloacetic Acids) 12.4 µg/L 60.0 µg/L
Chromium-6 0.06 µg/L 0.02 µg/L

✓ = below limit   ⚠ = above health goal   ✗ = exceeds guideline

How It Compares

Oxnard's water was long known as some of the hardest, most mineral-heavy in Ventura County; the GREAT program's desalting flipped that trajectory, and quality today is better than its old reputation suggests.

Tips

  • Taste has improved since RO blending began, but a pitcher filter still helps in higher-TDS neighborhoods
  • The city's annual report shows the current imported-versus-local blend
  • Softeners are common for appliances; safety doesn't require one

Frequently Asked Questions

Sources & References

The safety rating and guidance on this page draw on the following sources. See our full methodology.