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Hilmar-Irwin, CA Tap Water Quality 2026

Water quality report for Hilmar-Irwin, CA — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Hilmar-Irwin's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Hilmar County Water District PWSID: CA2410012 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead was not detected and no violations are open. PFAS was sampled but not enough times for a compliance determination.

B

Hilmar-Irwin earns a B for water quality

Graded on violations and lead, with state inspection findings. PFAS not tested.

Lead: not detected
PFAS sampled, too few results to judge
15 violations since 2015, 14 health-based
No violations currently open
Hilmar-Irwin's lead level vs. all California community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: Not detected — 0% of the federal action level
✓ Lower lead than % of California utilities
Population Served
5002
~1684 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
15 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
0% of EPA action level
Not detected
Action level: 15 ppb
Lead was not detected at the 90th percentile — the result fell below the laboratory detection limit. That is not the same as an absence of lead in every tap, and older homes with lead service lines can still show higher readings.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Nitrate MCL EXCEEDANCE 13.2 MG/L 10 mg/L 2025 Archived
Nitrate MCL EXCEEDANCE 28 MG/L 10 mg/L 2025 Archived
Nitrate MCL EXCEEDANCE 18.2 MG/L 10 mg/L 2025 Archived
Nitrate MCL EXCEEDANCE 11.3 MG/L 10 mg/L 2025 Archived
Nitrate MCL EXCEEDANCE 11.5 MG/L 10 mg/L 2025 Archived
Nitrate MCL EXCEEDANCE 10.6 MG/L 10 mg/L 2025 Archived
Nitrate MCL EXCEEDANCE 16.2 MG/L 10 mg/L 2024 Archived
Nitrate MCL EXCEEDANCE 11.7 MG/L 10 mg/L 2024 Archived
Nitrate MCL EXCEEDANCE 11.6 MG/L 10 mg/L 2024 Archived
Nitrate MCL EXCEEDANCE 31 MG/L 10 mg/L 2024 Archived
Nitrate MCL EXCEEDANCE 11.9 MG/L 10 mg/L 2024 Archived
Nitrate MCL EXCEEDANCE 15.9 MG/L 10 mg/L 2024 Archived
Nitrate MCL EXCEEDANCE 12.2 MG/L 10 mg/L 2024 Archived
Nitrate MCL EXCEEDANCE 14.7 MG/L 10 mg/L 2023 Archived
Nitrate MONITORING AND REPORTING — 10 mg/L 2019 Resolved
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

15 violations are on record since 2015, of which 14 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Hilmar County Water District
PWSID CA2410012
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 5,002
Service connections 1,684
Systems serving this area 1
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Hilmar-Irwin tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open.
Does Hilmar-Irwin water have PFAS? ▼
It was sampled, but no sampling point had enough results for a compliance determination.
Who supplies water to Hilmar-Irwin? ▼
Hilmar County Water District (PWSID CA2410012). Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2026-02-27. No significant deficiencies were recorded.

What Should Hilmar-Irwin Residents Do?

1
Read your annual water report
Your supplier publishes a Consumer Confidence Report each July covering the prior year.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

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