Public water system record
Twin Lakes Resort
Serves Potrero, San Diego County, CA · 400 people served
Federal records show 30 health-based violations and 10 monitoring/reporting issues for Twin Lakes Resort in the last ten years. The most serious issue in this window was a Arsenic violation that EPA lists as archived, not resolved.
System profile
Source water
Groundwater
ZIP
91942
EPA system ID
CA3701793
- Health-based violations, last 10 years
- 30
- Resolved
- 0
- Unresolved
- 0
- Archived by EPA
- 30
- Any acute record
- No
- Monitoring issues, last 10 years
- 10
Key facts
- Twin Lakes Resort draws water from 3 wells (2 of them for emergency, seasonal or other part-time use).
- Highest measured level in the last 10 years: Arsenic, 12.5 µg/L, federal limit 10 µg/L (1.3 times the limit), 2022.
- Most recent formal enforcement: compliance order with a penalty by California, August 2025.
- Record on file since 1980, with 3 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 0 unknown out of 149 service lines.
Check whether Twin Lakes Resort serves your address
Health-based violations
Since October 2016Violation 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 11.7 µg/L, federal limit 10 µg/L (1.2 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 12 µg/L, federal limit 10 µg/L (1.2 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 11.7 µg/L, federal limit 10 µg/L (1.2 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 11.7 µg/L, federal limit 10 µg/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.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 12 µg/L, federal limit 10 µg/L (1.2 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 12 µg/L, federal limit 10 µg/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.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 12 µg/L, federal limit 10 µg/L (1.2 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 12 µg/L, federal limit 10 µg/L (1.2 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 12 µg/L, federal limit 10 µg/L (1.2 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 12 µg/L, federal limit 10 µg/L (1.2 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 12.5 µg/L, federal limit 10 µg/L (1.3 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 12 µg/L, federal limit 10 µg/L (1.2 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 11.2 µg/L, federal limit 10 µg/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 12.2 µg/L, federal limit 10 µg/L (1.2 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 11.6 µg/L, federal limit 10 µg/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 11.8 µg/L, federal limit 10 µg/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 |
|
Arsenic
Contaminant limit exceeded
Measured 11.6 µg/L, federal limit 10 µg/L (1.2 times the limit)
|
330 | Jul 1, 2020 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 11.4 µg/L, federal limit 10 µg/L (1.1 times the limit)
|
330 | Apr 1, 2020 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 11.3 µg/L, federal limit 10 µg/L (1.1 times the limit)
|
330 | Jan 1, 2020 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 11.02 µg/L, federal limit 10 µg/L (1.1 times the limit)
|
330 | Jul 1, 2019 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 11 µg/L, federal limit 10 µg/L (1.1 times the limit)
|
330 | Apr 1, 2019 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 11.2 µg/L, federal limit 10 µg/L (1.1 times the limit)
|
330 | Jan 1, 2019 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 11.3 µg/L, federal limit 10 µg/L (1.1 times the limit)
|
330 | Oct 1, 2018 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
|
330 | Apr 1, 2018 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
|
330 | Jan 1, 2018 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
|
330 | Oct 1, 2017 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
|
330 | Jul 1, 2017 |
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, 2017 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 0.0115 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
330 | Jan 1, 2017 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Arsenic
Contaminant limit exceeded
Measured 0.0115 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
330 | Oct 1, 2016 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Arsenic
Monitoring and reporting
|
Jul 1, 2024 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Arsenic
Monitoring and reporting
|
Apr 1, 2023 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Nitrate
Monitoring and reporting
|
Jan 1, 2023 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Lead and Copper Rule
Monitoring and reporting
|
Oct 1, 2021 |
Active
Enforcement action in place
|
|
Arsenic
Monitoring and reporting
|
Oct 1, 2019 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Arsenic
Monitoring and reporting
|
Apr 1, 2017 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Public Notice
OTHER
|
Dec 23, 2016 |
Active
Enforcement action in place
|
|
Lead and Copper Rule
Monitoring and reporting
|
Apr 14, 2009 |
Active
Enforcement action in place
|
|
Lead and Copper Rule
Monitoring and reporting
|
Jun 25, 2007 |
Active
Enforcement action in place
|
|
Lead and Copper Rule
Monitoring and reporting
|
Jul 1, 1993 | Active |
Full record since 1980
EPA's records for Twin Lakes Resort go back to 1980. Before October 19, 2016 they list 3 health-based violations (3 archived by EPA without a recorded fix) and 20 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1980s | 0 | 12 |
| 1990s | 0 | 1 |
| 2000s | 0 | 5 |
| 2010 to October 18, 2016 | 3 | 2 |
| October 19, 2016 to 2019 | 10 | 3 |
| 2020s | 19 | 4 |
Most recent health-based violation before October 19, 2016: Arsenic, began October 2016, Archived.
Show all 3 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Arsenic
Contaminant limit exceeded
Measured 0.0115 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Oct 1, 2016 | Archived |
|
Arsenic
Contaminant limit exceeded
Measured 0.0114 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
|
Jul 1, 2016 | Archived |
|
Arsenic
Contaminant limit exceeded
Measured 0.0116 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
|
Apr 1, 2016 | Archived |
Enforcement actions
California regulators took 12 formal enforcement actions against Twin Lakes Resort between 2005 and 2025. The most recent was a compliance order with a penalty in August 2025.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Aug 4, 2025 | California | Compliance order with a penalty | 11 violations (6 health-based): Arsenic, Public Notice |
| Aug 5, 2024 | California | Compliance order with a penalty | 1 violation: Lead and Copper Rule |
| Mar 4, 2024 | California | Compliance order with a penalty | 1 violation: Nitrate |
| Dec 13, 2016 | California | Compliance order (no penalty) | 26 violations (26 health-based): Arsenic |
| Jun 1, 2016 | California | Compliance order (no penalty) | 4 violations (4 health-based): Arsenic |
| Sep 11, 2015 | California | Compliance order (no penalty) | 1 violation: Total Coliform |
| Apr 17, 2014 | California | Compliance order (no penalty) | 1 violation: Total Coliform |
| Dec 15, 2009 | California | Compliance order (no penalty) | 1 violation: Total Coliform |
| Apr 24, 2009 | California | Compliance order (no penalty) | 1 violation: Lead and Copper Rule |
| Mar 11, 2009 | California | Compliance order (no penalty) | 1 violation: Total Coliform |
| Jul 5, 2007 | California | Compliance order (no penalty) | 1 violation: Lead and Copper Rule |
| Jul 27, 2005 | California | Compliance order (no penalty) | 1 violation: Consumer Confidence Rule |
What the violations mean
Arsenic
30 incidentsArsenic exceeded the federal limit
Long-term arsenic exposure is linked to cancer and cardiovascular effects
Where the water comes from
Twin Lakes Resort draws water from 3 wells (2 of them for emergency, seasonal or other part-time use).
Annual water quality report
Twin Lakes Resort 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 Twin Lakes Resort 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