How does Oxnard's water compare to the national average?

The USA national average is 151 mg/L. Oxnard (285 mg/L) is 134 mg/L harder than average.

Oxnard Water Hardness & Quality Report (2026)

Water Hardness

285mg/L

Very Hard

16.6 grains per gallon

Source

reservoir

pH Level

7.6

neutral = 7.0

Lead

0.005 mg/L

✓ Below action level

TDS

209.6 mg/L

Est. Daily Cost

$0.76

energy & soap waste

Source: See methodology section below · Updated 2026

285mg/L as CaCO₃Very Hard

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Oxnard, your appliances are currently losing 38% efficiency due to mineral buildup.

Appliance	In Oxnard	Soft Water City	Efficiency Loss
Kettle	1.5 yrs	8.5 yrs	-82%
Washing Machine	3.1 yrs	12 yrs	-74%
Water Heater	5 yrs	15 yrs	-67%

Regional Water Comparison

How Oxnard compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Oxnard, California	285 mg/L	0 ppt	🔴 Very Hard	reservoir
Port Hueneme, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
Camarillo, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
Ventura, California	≈ 180+ mg/L	6.1 ppt	🔴 Very Hard	reservoir
Santa Paula, California	≈ 180+ mg/L	0 ppt	🔴 Very Hard	groundwater

National Benchmark

How Oxnard compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Oxnard	285 mg/L	🔴 High
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Oxnard's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 209.6 mg/LpH: 7.6

The City of Oxnard Public Works Department supplies drinking water to approximately 200,000 residents in Ventura County, California. The utility blends three sources: imported surface water from the Calleguas Municipal Water District (CMWD), which delivers State Project Water via the Metropolitan Water District of Southern California (MWDSC) treated at the Joseph Jensen Filtration Facility; groundwater from the Oxnard Plain aquifers via city wells; and desalinated local groundwater. The United Water Conservation District (UWCD) contributes Santa Clara River diversions for aquifer replenishment, with distribution through blending stations citywide.

The primary watershed encompasses the Santa Clara River, draining from the Santa Ynez Mountains through Ventura County to the Pacific Ocean across alluvial plains and coastal sediments. Local supply relies on the Oxnard Forebay and Pressure Areas of the Oxnard Plain groundwater basin, a shallow unconsolidated aquifer recharged by river percolation and rainfall. These formations, rich in calcareous materials from Pleistocene marine deposits, impart a hard character to the groundwater, while imported supplies from Sierra Nevada granitic watersheds carry moderate mineralization. The desalter targets brackish zones influenced by seawater intrusion, yielding softer contributions to the blend.

At 285 mg/L, Oxnard's water is classified very hard, promoting significant scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and increasing energy costs. Soap lathering is poor, leading to residue on dishes, skin dryness, and faded laundry. Regular descaling of fixtures, installing sediment filters, and flushing heaters annually are recommended; a water softener is strongly advised given the very hard classification. Oxnard's water meets state and federal standards per the latest Consumer Confidence Report; fluoride averages near 0.5 ppm from blended sources and pH is neutral to slightly alkaline. Lead and Copper Rule compliance is maintained through corrosion control.

Geology & Source: Oxnard Plain coastal alluvial aquifer — Quaternary sediments over Pleistocene marine deposits; limestone and dolomite fragments dissolve calcium and magnesium; blended with Sierra Nevada granitic State Water Project imports and desalinated

Other California Water Reports

Port Hueneme

≈ 120–179 mg/L

🟠 Hard

Camarillo

≈ 120–179 mg/L

🟠 Hard

Ventura

≈ 180+ mg/L

🔴 Very Hard

Santa Paula

≈ 180+ mg/L

🔴 Very Hard

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Frequently Asked Questions

Is Oxnard's water safe to drink?

Yes. Oxnard's water meets all federal safety standards. The hardness is 285 mg/L (Very Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Oxnard?

At 285 mg/L (Very Hard), Oxnard's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 38%.

How does Oxnard compare to the USA average?

The USA national average is 151 mg/L. Oxnard (285 mg/L) is 134 mg/L above the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Oxnard is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.