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Public water system record

Willow Park Marina

Serves an area of Contra Costa County, CA · 380 people served

Federal records show 20 health-based violations and no monitoring/reporting issues for Willow Park Marina in the last ten years. The most serious issue in this window was a Arsenic violation that EPA lists as archived, not resolved.

  • CA0707507
  • OAKLEY
  • CA
  • 380 served

System profile

Source water Groundwater
ZIP 94561
EPA system ID CA0707507

Verify this system on EPA ECHO →

Health-based violations, last 10 years
20
Resolved
0
Unresolved
0
Archived by EPA
20
Any acute record
No
Monitoring issues, last 10 years
0

Key facts

  • Willow Park Marina draws water from 2 wells.
  • Highest measured level in the last 10 years: Arsenic, 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit), 2021.
  • Most recent formal enforcement: compliance order (no penalty) by California, February 2021.
  • Lead pipe inventory: 0 lead and 0 unknown out of 166 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
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 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.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 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.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Apr 1, 2025 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 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.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Oct 1, 2024 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 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.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 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.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 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.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Oct 1, 2023 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Jul 1, 2023 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Apr 1, 2023 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 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.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Oct 1, 2022 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Jul 1, 2022 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Apr 1, 2022 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Jan 1, 2022 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Oct 1, 2021 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 330 Jul 1, 2021 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
 330 Apr 1, 2021 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No
Arsenic
Contaminant limit exceeded
Measured 0.012 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
 330 Jan 1, 2021 Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
 No

Enforcement actions

California regulators took 1 formal enforcement action against Willow Park Marina in 2021. The most recent was a compliance order (no penalty) in February 2021.

Date By Action Violations covered
Feb 26, 2021 California Compliance order (no penalty) 20 violations (20 health-based): Arsenic

What the violations mean

Arsenic

20 incidents

Arsenic exceeded the federal limit

Long-term arsenic exposure is linked to cancer and cardiovascular effects

Where the water comes from

Willow Park Marina draws water from 2 wells.

Annual water quality report

Willow Park Marina 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.

Systems serving 500 or fewer people may meet the rule by telling customers the report is available on request, so you may need to ask Willow Park Marina for a copy.

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