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Public water system record

Hilmar County Water District

Serves Hilmar-Irwin, Merced County, CA · 5,504 people served

Federal records show 14 health-based violations and 1 monitoring/reporting issue for Hilmar County Water District in the last ten years. The most serious issue in this window was a Nitrate violation that EPA lists as archived, not resolved.

  • CA2410012
  • HILMAR
  • CA
  • 5,504 served

System profile

Source water Groundwater
ZIP 95324
EPA system ID CA2410012

Verify this system on EPA ECHO →

Health-based violations, last 10 years
14
Resolved
0
Unresolved
0
Archived by EPA
14
Any acute record
Yes
Monitoring issues, last 10 years
1

Key facts

  • Hilmar County Water District draws water from 3 wells (1 of them for emergency, seasonal or other part-time use).
  • Highest measured level in the last 10 years: Nitrate, 31 mg/L, federal limit 10 mg/L (3.1 times the limit), 2024.
  • Most recent formal enforcement: compliance order (no penalty) by California, October 2024.
  • Record on file since 1981, with 3 health-based violations before October 19, 2016.
  • Lead pipe inventory: 0 lead and 388 unknown out of 1,700 service lines.

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Health-based violations

Since October 2016

Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.

Contaminant Rule family Start date Status Acute
Nitrate
Contaminant limit exceeded
Measured 13.2 mg/L, federal limit 10 mg/L (1.3 times the limit)
 330 Nov 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 28 mg/L, federal limit 10 mg/L (2.8 times the limit)
 330 Oct 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 18.2 mg/L, federal limit 10 mg/L (1.8 times the limit)
 330 Jul 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 11.3 mg/L, federal limit 10 mg/L (1.1 times the limit)
 330 Mar 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 11.5 mg/L, federal limit 10 mg/L (1.2 times the limit)
 330 Feb 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 10.6 mg/L, federal limit 10 mg/L (1.1 times the limit)
 330 Jan 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 16.2 mg/L, federal limit 10 mg/L (1.6 times the limit)
 330 Dec 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 11.7 mg/L, federal limit 10 mg/L (1.2 times the limit)
 330 Jul 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 11.6 mg/L, federal limit 10 mg/L (1.2 times the limit)
 330 May 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 31 mg/L, federal limit 10 mg/L (3.1 times the limit)
 330 Apr 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 11.9 mg/L, federal limit 10 mg/L (1.2 times the limit)
 330 Mar 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 15.9 mg/L, federal limit 10 mg/L (1.6 times the limit)
 330 Feb 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 12.2 mg/L, federal limit 10 mg/L (1.2 times the limit)
 330 Jan 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes
Nitrate
Contaminant limit exceeded
Measured 14.7 mg/L, federal limit 10 mg/L (1.5 times the limit)
 330 Jan 1, 2023 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 Yes

Monitoring and reporting issues

Since October 2016

Missed tests or reports, not contaminants found above a limit.

Issue Start date Status
Nitrate
Monitoring and reporting
 Jan 1, 2019 Resolved

Full record since 1981

EPA's records for Hilmar County Water District go back to 1981. Before October 19, 2016 they list 3 health-based violations (3 archived by EPA without a recorded fix) and no monitoring or reporting violations.

Violations that began in Health-based Monitoring and reporting
1980s 3 0
October 19, 2016 to 2019 0 1
2020s 14 0

Most recent health-based violation before October 19, 2016: Nitrate (acute), began July 1983, Archived.

Show all 3 health-based violations before October 19, 2016
Contaminant Start date Status
Nitrate (acute)
Contaminant limit exceeded
 Jul 1, 1983 Archived
Nitrate (acute)
Contaminant limit exceeded
 Aug 1, 1982 Archived
Nitrate (acute)
Contaminant limit exceeded
 Jan 1, 1981 Archived

Enforcement actions

California regulators took 2 formal enforcement actions against Hilmar County Water District between 2020 and 2024. The most recent was a compliance order (no penalty) in October 2024.

Date By Action Violations covered
Oct 2, 2024 California Compliance order (no penalty) 14 violations (14 health-based): Nitrate
Mar 10, 2020 California Compliance order (no penalty) 1 violation: Nitrate

What the violations mean

Nitrate

14 incidents

Nitrate exceeded the federal limit

High nitrate is especially dangerous for infants under 6 months and can cause blue baby syndrome

Where the water comes from

Hilmar County Water District draws water from 3 wells (1 of them for emergency, seasonal or other part-time use).

Annual water quality report

Hilmar County Water District must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.

Where the state allows it, systems serving fewer than 10,000 people may publish the report in a local newspaper or news site instead of mailing it, and must provide a copy on request.

Find a posted report with EPA's Consumer Confidence Report search

Testing your own water

To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by California.

Certified drinking water labs by state EPA guidance for private wells