Lone Pine Oasis
PWSID: CA1400037
This system has no unresolved violations. The most recent violation on record was 2022-10-01.
This system has more violations on record than 99% of water systems in California.
Violation trend: 0.8 per year over the last 5 years, down from 18.0 per year in the previous 5.
System Details
| Population Served | 49 |
| Service Connections | 48 |
| Water Source | Groundwater |
| System Type | Transient Non-Community |
| Owner | Private |
| Status | Active |
| City | Valley Center |
| EPA ZIP on File | 92082 |
Lead & Copper Testing
| Contaminant | Level | EPA Action Level | Status |
|---|---|---|---|
| Lead (90th percentile) | 0.0050 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0026 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0026 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0000 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0000 mg/L | 0.015 mg/L | Below Action Level |
Violation History (175 total)
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 1005 | MCL Measured: 10.80 UG/L (EPA limit: 0.010 mg/L) | 2022-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 10.80 UG/L (EPA limit: 0.010 mg/L) | 2022-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 10.80 UG/L (EPA limit: 0.010 mg/L) | 2022-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 10.80 UG/L (EPA limit: 0.010 mg/L) | 2022-10-01 | Yes | Acknowledged |
| 4109 | MR | 2020-10-01 | Major | Returned to Compliance |
| 4109 | MR | 2020-10-01 | Major | Returned to Compliance |
| 4109 | MR | 2020-10-01 | Major | Acknowledged |
| 4109 | MR | 2020-10-01 | Major | Returned to Compliance |
| 4109 | MR | 2020-10-01 | Major | Acknowledged |
| 4006 | MCL Measured: 23.00 PCI/L (limit: 20.00 PCI/L) | 2020-04-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 23.00 PCI/L (limit: 20.00 PCI/L) | 2020-04-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 23.00 PCI/L (limit: 20.00 PCI/L) | 2020-04-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 23.00 PCI/L (limit: 20.00 PCI/L) | 2020-04-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 24.00 PCI/L (limit: 20.00 PCI/L) | 2020-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 24.00 PCI/L (limit: 20.00 PCI/L) | 2020-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 24.00 PCI/L (limit: 20.00 PCI/L) | 2020-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 24.00 PCI/L (limit: 20.00 PCI/L) | 2020-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 26.00 PCI/L (limit: 20.00 PCI/L) | 2019-10-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 26.00 PCI/L (limit: 20.00 PCI/L) | 2019-10-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 26.00 PCI/L (limit: 20.00 PCI/L) | 2019-10-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 26.00 PCI/L (limit: 20.00 PCI/L) | 2019-10-01 | Yes | Acknowledged |
| 5000 | MR | 2019-10-01 | Returned to Compliance | |
| 5000 | MR | 2019-10-01 | Returned to Compliance | |
| 5000 | MR | 2019-10-01 | Returned to Compliance | |
| 5000 | MR | 2019-10-01 | Returned to Compliance | |
| 4006 | MCL Measured: 22.00 PCI/L (limit: 20.00 PCI/L) | 2019-07-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 22.00 PCI/L (limit: 20.00 PCI/L) | 2019-07-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 22.00 PCI/L (limit: 20.00 PCI/L) | 2019-07-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 22.00 PCI/L (limit: 20.00 PCI/L) | 2019-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0250 MG/L (limit: 0.0100 MG/L) | 2018-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0250 MG/L (limit: 0.0100 MG/L) | 2018-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0250 MG/L (limit: 0.0100 MG/L) | 2018-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0250 MG/L (limit: 0.0100 MG/L) | 2018-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0400 MG/L (limit: 0.0100 MG/L) | 2018-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0400 MG/L (limit: 0.0100 MG/L) | 2018-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0400 MG/L (limit: 0.0100 MG/L) | 2018-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0400 MG/L (limit: 0.0100 MG/L) | 2018-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0480 MG/L (limit: 0.0100 MG/L) | 2018-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0480 MG/L (limit: 0.0100 MG/L) | 2018-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0480 MG/L (limit: 0.0100 MG/L) | 2018-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0480 MG/L (limit: 0.0100 MG/L) | 2018-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 25.00 PCI/L (limit: 20.00 PCI/L) | 2018-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 25.00 PCI/L (limit: 20.00 PCI/L) | 2018-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 25.00 PCI/L (limit: 20.00 PCI/L) | 2018-01-01 | Yes | Acknowledged |
| 4006 | MCL Measured: 25.00 PCI/L (limit: 20.00 PCI/L) | 2018-01-01 | Yes | Acknowledged |
| 5000 | MR | 2017-10-01 | Returned to Compliance | |
| 5000 | MR | 2017-10-01 | Returned to Compliance | |
| 5000 | MR | 2017-10-01 | Returned to Compliance | |
| 5000 | MR | 2017-10-01 | Returned to Compliance | |
| 1005 | MCL Measured: 0.0520 MG/L (limit: 0.0100 MG/L) | 2017-10-01 | Yes | Acknowledged |
Showing 50 of 175 historical violations.
Understanding This Water System's Record
Lone Pine Oasis is a transient non-community water system that draws from groundwater sources and serves a population of 49 in Valley Center, California. This page shows its complete compliance history as reported to the EPA's Safe Drinking Water Information System (SDWIS), the federal database that tracks every public water system in the United States.
What Do These Violations Mean?
Health-based violations mean the system exceeded an EPA maximum contaminant level (MCL) or failed to provide required treatment. These indicate potential health risks from contaminants like lead, arsenic, bacteria, nitrates, or disinfection byproducts. Non-health-based violations involve monitoring, reporting, or procedural requirements — the system missed a testing deadline or failed to notify customers, but contaminant levels were not necessarily unsafe.
What Should You Do?
Your water utility is required to publish an annual Consumer Confidence Report (CCR) that details test results and any violations. If your system has active health-based violations, consider a certified water filter rated for the specific contaminants involved. The contaminant guides on this site explain health risks and filter options for common pollutants. For the most current results, contact your water utility directly — EPA data can lag weeks or months behind real-time testing.