Halcyon Water System
EPA ID: CA4000501 · 110 people served · 1 ZIP code
ZipCheckup's reading of EPA records for Halcyon Water System (CA4000501): 2 violations recorded with unresolved status in the SDWIS data used. In the federal compliance data used here, Halcyon Water System has 2 violations listed as open; the utility serves approximately 110 people.
Data: EPA SDWIS
Service Area Map
Coverage area for Halcyon Water System Source: EPA SDWIS service area boundaries.
Service area boundary
Demographics of ZIP Codes Served
The ZIP codes associated with Halcyon Water System have a median household income of $75,012 and about 6,812 residents live in those ZIP codes (Census; not the number of people this system supplies). Approximately 65% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Halcyon Water System's water is classified in EPA records as a groundwater source. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in California
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Halcyon Water System (EPA ID: CA4000501) is a community water system in California that serves approximately 110 people from groundwater sources.
This system serves ZIP code 93445 in Oceano.
Violation History
Status breakdown for accepted records with record years 2021-2026: 1 resolved, 19 archived, 0 addressed, and 2 unaddressed. Under this source contract, current noncompliance is the sum of addressed and unaddressed records. Archived and resolved records are excluded from current noncompliance.
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| January 1, 2026 | Selenium | Non-health-based | Archived |
| October 1, 2025 | Selenium | Non-health-based | Archived |
| July 1, 2025 | Selenium | Non-health-based | Archived |
| January 1, 2025 | Selenium | Non-health-based | Archived |
| October 17, 2024 | LEAD AND COPPER RULE REVISIONS | Health-based | Unaddressed (current) |
| October 17, 2024 | LEAD AND COPPER RULE REVISIONS | Non-health-based | Unaddressed (current) |
| October 1, 2024 | Selenium | Non-health-based | Archived |
| July 1, 2024 | Selenium | Non-health-based | Archived |
| April 1, 2024 | Selenium | Non-health-based | Archived |
| January 1, 2024 | Nitrate | Non-health-based | Resolved |
| July 1, 2023 | Nitrate | Non-health-based | Archived |
| April 1, 2023 | Nitrate | Non-health-based | Archived |
| January 1, 2023 | Nitrate | Non-health-based | Archived |
| January 1, 2023 | Nitrate | Non-health-based | Archived |
| October 1, 2022 | Nitrate | Non-health-based | Archived |
| October 1, 2022 | Nitrate | Non-health-based | Archived |
| July 1, 2022 | Nitrate | Non-health-based | Archived |
| January 1, 2022 | Nitrate | Non-health-based | Archived |
| October 1, 2021 | Nitrate | Non-health-based | Archived |
| July 1, 2021 | Nitrate | Non-health-based | Archived |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Nitrate | Monitoring & Reporting | 13 | No |
| Selenium | Other Violation | 7 | No |
| LEAD AND COPPER RULE REVISIONS | Treatment Technique, Monitoring & Reporting | 2 | Yes |
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Ask your water utility whether running cold water for 2 minutes is enough to flush your plumbing before drinking.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by CA or modeled from parcel and building-footprint data.
- 93445 - Oceano
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View available EPA compliance records for Halcyon Water System (CA4000501) on EPA.gov.
Frequently Asked Questions
Is Halcyon Water System water safe to drink?
The accepted 2026Q2 ECHO snapshot shows 1 current health-based noncompliance record for Halcyon Water System. Review the utility's current notices and EPA record. This system-level compliance history cannot determine conditions at a specific tap.
How many people does Halcyon Water System serve?
Halcyon Water System serves approximately 110 people across 1 ZIP code in California.
Where does Halcyon Water System get its water?
The primary water source is groundwater.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Halcyon Water System (CA): 1 Health Violation. https://zipcheckup.com/water-system/ca4000501/
@misc{zipcheckup-water-system-ca4000501,
author = {{ZipCheckup}},
title = {{Halcyon Water System (CA): 1 Health Violation}},
year = {n.d.},
url = {https://zipcheckup.com/water-system/ca4000501/}
}
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Halcyon Water System (EPA ID: CA4000501) - request the latest Consumer Confidence Report or ask about specific contaminants.