Hardness
Very hard average418.6mg/L as CaCO₃
System average; range 131–930
USGS hardness classes
About 24.5 grains per gallon. Use a current home measurement for softener settings.
2025View source
- 1Your water
- 2Your home
- 3Your system
Ventura County Water Quality Report
Showing utility report
City of Oxnard Water
2025 utility report; each result retains its measurement period
Results for City of Oxnard Water in Ventura County. Confirm the supplier and system on your bill.
Your water at a glance
See the amount, the comparison and what it means. “Below” refers to the stated benchmark, not zero risk.
Disinfectant residual
Reported level below MRDL1.51mg/L
Total chlorine residual average; range 0.06–3
MRDL: 4 mg/L
Match the filter to the disinfectant used by this utility.
2025View source
TTHMs
Reported level below benchmark22.17µg/L (ppb)
Greatest locational running annual average; range 9.5–36
Report MCL: 80 µg/L
A system result does not measure the water at an individual home.
2025View source
HAA5
Reported level below benchmark3.7µg/L (ppb)
Greatest locational running annual average; range 1.6–7.3
Report MCL: 60 µg/L
A system result does not measure the water at an individual home.
2025View source
Fluoride
Below report benchmark0.66mg/L
Printed system average; range needs clarification
California MCL: 2 mg/L
The printed average falls outside the printed range. Confirm that row with the utility.
2025View source
Lead
90th percentile below action level5.5µg/L (ppb)
90th percentile; 50 sampled sites
Report action level: 15 µg/L
Three sampled sites exceeded 15 µg/L. The 90th percentile does not rule out higher lead at a particular tap.
2024View source
Your provider needs its own report.
Continue with your home details for general filtration guidance. We will not use another utility’s numbers as your result.
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A city report cannot establish a well’s water quality. Well-water treatment depends on your test results and site conditions.
Explore well-water systems →Water hardness by provider
The figures below are provider-specific. They are not a countywide average.
| Utility | Hardness | Hardness source |
|---|---|---|
| 418.6 mg/L · Very hard average | 2025 |
View Full Water ReportOpen the measured results, dates, comparisons and original utility report.
The numbers behind your report
Selected results with the original sampling dates and measurement basis. Open the utility report for every parameter, notice and footnote.
Open the complete utility report ↗
| What was measured | Reported amount | Sample year / source date | How to read it |
|---|---|---|---|
| Hardness | 418.6 mg/L as CaCO₃System average; range 131–930 | 2025View source ↗ | Very hard averageAbout 24.5 grains per gallon. Use a current home measurement for softener settings. |
| Disinfectant residual | 1.51 mg/LTotal chlorine residual average; range 0.06–3 | 2025View source ↗ | Reported level below MRDLMatch the filter to the disinfectant used by this utility. |
| TTHMs | 22.17 µg/L (ppb)Greatest locational running annual average; range 9.5–36 | 2025View source ↗ | Reported level below benchmarkA system result does not measure the water at an individual home. |
| HAA5 | 3.7 µg/L (ppb)Greatest locational running annual average; range 1.6–7.3 | 2025View source ↗ | Reported level below benchmarkA system result does not measure the water at an individual home. |
| Fluoride | 0.66 mg/LPrinted system average; range needs clarification | 2025View source ↗ | Below report benchmarkThe printed average falls outside the printed range. Confirm that row with the utility. |
| Lead | 5.5 µg/L (ppb)90th percentile; 50 sampled sites | 2024View source ↗ | 90th percentile below action levelThree sampled sites exceeded 15 µg/L. The 90th percentile does not rule out higher lead at a particular tap. |
| Nitrate as nitrogen | 1.88 mg/LSystem average; range 0.44–7 | 2025View source ↗ | Reported average below benchmarkNitrate requires treatment selected for that specific contaminant. |
| PFHxS | 0.69 ng/L (ppt)UCMR5 average; range 0.43–0.86 | 2025View source ↗ | DetectedThis is one PFAS compound, not a total for all PFAS. Match any treatment claim to the specific compound. |
In drinking water, ppm ≈ mg/L, ppb ≈ µg/L and ppt ≈ ng/L. Calculated hardness in grains per US gallon (gpg) = mg/L as CaCO₃ ÷ 17.118, rounded to one decimal. ND means below the reporting limit, not zero.
MCL is an enforceable contaminant limit; MRDL is a disinfectant limit. A PHG is a health goal, not the legal limit. Lead/copper action levels use system sampling percentiles, not a safe-tap threshold. TTHM/HAA5 comparisons use locational running annual averages.
PFAS results are compound-specific. Source monitoring, entry-point samples and tap tests are different. Notification and response levels in a utility report are not maximum contaminant levels; do not infer a compliance violation from a single value. EPA PFAS benchmarks and implementation ↗
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Source water. A blend of City groundwater, United Water Conservation District supply, and imported water through Calleguas Municipal Water District.
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More about your local water
What this means for your home
Oxnard’s 2025 hardness average is 418.6 mg/L, in the very hard category.
Use this report when City of Oxnard Water is on your bill. Ventura County has other municipal systems, water districts, and private wells. Oxnard’s blend and measurements do not describe every address in the county.
A useful local question
What does Oxnard’s hardness result mean for a Ventura County home?
The utility average supports reviewing a softener for scale control in the Oxnard system. Confirm the supplier and measure incoming hardness before sizing. Homes supplied by another utility or a private well need their own results.
Sources and methodology
We keep each utility’s results separate, show the reported sample year, and distinguish averages, maxima and tap-sampling percentiles. Hardness classifications use USGS ranges. Missing data stays unknown.
Different name on your water bill?
These local providers publish separate reports. Follow the matching utility link; the measurements above do not describe these systems.
- City of Oxnard Water ↗2025 utility report; each result retains its measurement period
- USGS hardness classification
- EPA PFAS benchmarks and implementation
Sources checked November 15, 2026
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