TWIN LAKES RESORT water quality, CA

At a glance

Recent tests are below federal safety limits

No lead reported

Lead service lines

No lead reported in inventory

This utility's inventory reports no confirmed lead service lines and a low share of unclassified lines.

From the utility's published inventory · See details below
Not fluoridated

Fluoride

Not added

CDC's My Water's Fluoride listing does not report this system as fluoridating its drinking water.

Per CDC My Water's Fluoride · See details below

Past 5 years: 14 health-based violations on file, all marked Resolved or Archived. See compliance history below.

Risk classification follows EPA's published values for safe drinking water, with caution and concern bands reviewed by a clinician. Past resolved violations do not influence this card. See methodology.

Lead service line inventory

Utility reports no confirmed lead service lines

TWIN LAKES RESORT reports 0 confirmed lead service lines, 149 non-lead, 0 unknown (total 149) in the EPA SDWIS service line inventory (2026Q1).

0 confirmed lead service lines
0 galvanized requiring replacement (LCRI treats these as lead)
0 unknown (0.0% of total)
149 confirmed non-lead (100.0%)
149 total service lines in the system

What to do if your service line might be lead

Ask your utility to check the service-line classification for your specific address. Many utilities provide a public address-lookup tool linked from the inventory page.
Get on the replacement queue. Under the LCRI, utilities must replace all lead and galvanized-requiring- replacement lines within 10 years (clock generally starts November 2027). Some prioritize requests.
Until the line is replaced: flush the tap 30 seconds after long stagnation, use cold water for drinking and cooking, and consider an NSF/ANSI 53 lead-rated tap filter.
Talk to your clinician about a blood lead test for anyone in the home, especially a pregnant person or a child under 6. Lead in drinking water guide.

Inventory data sourced from TWIN LAKES RESORT ( retrieved May 24, 2026 ; curator confidence: high ). Confirmed against the original source automatically each month; see methodology.

Lead and copper test results

The most recent measurement per contaminant from EPA's Lead and Copper Rule sampling.

Why only lead and copper, and not arsenic, nitrate, or others?

EPA's bulk SDWIS download is the only nationwide per-system sample data they publish, and it only includes the Lead and Copper Rule table. Values for other regulated contaminants (TTHMs, nitrate, arsenic, etc.) appear on this page only when they trigger a violation. For the full per-system contaminant suite, see the utility's annual Consumer Confidence Report (link further down the page).

Most recent measurements per contaminant (Lead and Copper Rule) . Sorted by risk: concern first, then caution, then unrated, then safe.
Contaminant	Most recent	Date	Risk
Lead PB90	0 mg/L	December 31, 2024	Below regulatory thresholds Lead has no safe level (MCLG=0). LCR action level is 0.015 mg/L for the 90th-percentile sample; the LCRI (Oct 2024) lowers the action level to 0.010 mg/L effective Nov 2027. Caution at any detection above LOD; concern anchored to the future LCRI value (0.010 mg/L) for forward consistency. Learn more about Lead. Source.

Data from EPA SDWIS (Lead and Copper Rule sample table) , last refreshed May 24, 2026.

Fluoride

Per CDC My Water's Fluoride

TWIN LAKES RESORT does not add fluoride to its drinking water.

This system has not reported adding fluoride to its water on CDC's My Water's Fluoride listing. Natural fluoride may still be present at trace levels from the source water; the utility's annual water quality report has the latest measured concentration.

Source: CDC My Water's Fluoride, listed under Twin Lakes Resort (San Diego County). Verify on CDC's site .

Area context

San Diego County, CA (2020 data)

Community water systems: 23 of 73 add fluoride
Population on fluoridated water: 2,693,967 of 2,955,559 (91.1%)

California statewide (2020 data)

Population on fluoridated water: 21,879,582 of 38,051,212 (57.5%)
Community water systems adding fluoride: 417 of 3,057

Data from CDC My Water's Fluoride (per-system status) , last refreshed May 19, 2026.

Data from CDC Water Fluoridation Reporting System (state and county aggregates) , last refreshed May 16, 2026.

Recorded contaminant measurements (from violations)

When this system exceeded a regulatory limit and EPA recorded the measured value, that value is shown here. These are not routine sample results: they are the values the violation was triggered on.

Measured values from recorded violations . Most recent first.
Period	Contaminant	Measured	Federal MCL	Status
April 1, 2025	Arsenic	11.7UG/L	0.01 UG/L	Health-based
January 1, 2025	Arsenic	12UG/L	0.01 UG/L	Health-based
October 1, 2024	Arsenic	11.7UG/L	0.01 UG/L	Health-based
July 1, 2024	Arsenic	11.7UG/L	0.01 UG/L	Health-based
April 1, 2024	Arsenic	12UG/L	0.01 UG/L	Health-based
January 1, 2024	Arsenic	12UG/L	0.01 UG/L	Health-based
October 1, 2023	Arsenic	12UG/L	0.01 UG/L	Health-based
July 1, 2023	Arsenic	12UG/L	0.01 UG/L	Health-based
January 1, 2023	Arsenic	12UG/L	0.01 UG/L	Health-based
October 1, 2022	Arsenic	12UG/L	0.01 UG/L	Health-based
July 1, 2022	Arsenic	12.5UG/L	0.01 UG/L	Health-based
April 1, 2022	Arsenic	12UG/L	0.01 UG/L	Health-based
January 1, 2022	Arsenic	11.2UG/L	0.01 UG/L	Health-based
July 1, 2021	Arsenic	12.2UG/L	0.01 UG/L	Health-based

Data from EPA SDWIS (violation records) , last refreshed May 24, 2026.

Compliance history

EPA-recorded violations against this system over the last 5 years.

How to read this section

Health-based violations are when a measured limit was exceeded; the measured concentration is shown alongside the EPA federal limit where SDWIS published it. Monitoring and reporting items are paperwork issues (missed sample dates, late filings) that do not themselves indicate unsafe water.

14 resolved health-based violations in the last 5 years

All 14 health-based violations in the last 5 years are marked Resolved or Archived. Past violations do not represent current water quality.

Health-based violations in the last 5 years
Period start	Contaminant	What happened	Measured level	Status
April 1, 2025	Arsenic	Maximum Contaminant Level Violation, Average	11.70 UG/L MCL 0.010 UG/L	Resolved
January 1, 2025	Arsenic	Maximum Contaminant Level Violation, Average	12 UG/L MCL 0.010 UG/L	Resolved
October 1, 2024	Arsenic	Maximum Contaminant Level Violation, Average	11.70 UG/L MCL 0.010 UG/L	Resolved
July 1, 2024	Arsenic	Maximum Contaminant Level Violation, Average	11.70 UG/L MCL 0.010 UG/L	Resolved
April 1, 2024	Arsenic	Maximum Contaminant Level Violation, Average	12 UG/L MCL 0.010 UG/L	Resolved
January 1, 2024	Arsenic	Maximum Contaminant Level Violation, Average	12 UG/L MCL 0.010 UG/L	Resolved
October 1, 2023	Arsenic	Maximum Contaminant Level Violation, Single Sample	12 UG/L MCL 0.010 UG/L	Resolved
July 1, 2023	Arsenic	Maximum Contaminant Level Violation, Single Sample	12 UG/L MCL 0.010 UG/L	Resolved
January 1, 2023	Arsenic	Maximum Contaminant Level Violation, Single Sample	12 UG/L MCL 0.010 UG/L	Resolved
October 1, 2022	Arsenic	Maximum Contaminant Level Violation, Single Sample	12 UG/L MCL 0.010 UG/L	Resolved
July 1, 2022	Arsenic	Maximum Contaminant Level Violation, Single Sample	12.50 UG/L MCL 0.010 UG/L	Resolved
April 1, 2022	Arsenic	Maximum Contaminant Level Violation, Single Sample	12 UG/L MCL 0.010 UG/L	Resolved
January 1, 2022	Arsenic	Maximum Contaminant Level Violation, Single Sample	11.20 UG/L MCL 0.010 UG/L	Resolved
July 1, 2021	Arsenic	Maximum Contaminant Level Violation, Single Sample	12.20 UG/L MCL 0.010 UG/L	Resolved

4 monitoring and reporting item s (paperwork) , 1 still open · these are not health risks

Monitoring and reporting items in the last 5 years
Period start	Relates to	Item	Status
July 1, 2024	Arsenic	Monitoring, Check/Repeat/Confirmation	Resolved
April 1, 2023	Arsenic	Monitoring, Check/Repeat/Confirmation	Resolved
January 1, 2023	Nitrate	Monitoring, Regular	Resolved
October 1, 2021	Lead and Copper Rule	Follow-up Or Routine LCR Tap M/R	Addressed

23 older violation s (5-10 years ago) · 20 health-based, 3 paperwork , 1 still open

Violations 5-10 years ago (23 total)
Period start	Relates to	Item	Measured level	Status
April 1, 2021	Arsenic	Maximum Contaminant Level Violation, Single Sample	11.60 UG/L MCL 0.010 UG/L	Resolved
January 1, 2021	Arsenic	Maximum Contaminant Level Violation, Average	11.80 UG/L MCL 0.010 UG/L	Resolved
July 1, 2020	Arsenic	Maximum Contaminant Level Violation, Average	11.60 UG/L MCL 0.010 UG/L	Resolved
April 1, 2020	Arsenic	Maximum Contaminant Level Violation, Average	11.40 UG/L MCL 0.010 UG/L	Resolved
January 1, 2020	Arsenic	Maximum Contaminant Level Violation, Average	11.30 UG/L MCL 0.010 UG/L	Resolved
October 1, 2019	Arsenic	Monitoring, Check/Repeat/Confirmation	—	Resolved
July 1, 2019	Arsenic	Maximum Contaminant Level Violation, Average	11.02 UG/L MCL 0.010 UG/L	Resolved
April 1, 2019	Arsenic	Maximum Contaminant Level Violation, Average	11 UG/L MCL 0.010 UG/L	Resolved
January 1, 2019	Arsenic	Maximum Contaminant Level Violation, Average	11.20 UG/L MCL 0.010 UG/L	Resolved
October 1, 2018	Arsenic	Maximum Contaminant Level Violation, Average	11.30 UG/L MCL 0.010 UG/L	Resolved
April 1, 2018	Arsenic	Maximum Contaminant Level Violation, Average	12 MG/L MCL 0.010 MG/L	Resolved
January 1, 2018	Arsenic	Maximum Contaminant Level Violation, Average	12 MG/L MCL 0.010 MG/L	Resolved
October 1, 2017	Arsenic	Maximum Contaminant Level Violation, Average	12 MG/L MCL 0.010 MG/L	Resolved
July 1, 2017	Arsenic	Maximum Contaminant Level Violation, Average	11.75 MG/L MCL 0.010 MG/L	Resolved
April 1, 2017	Arsenic	Maximum Contaminant Level Violation, Average	0.012 MG/L MCL 0.010 MG/L	Resolved
April 1, 2017	Arsenic	Monitoring, Check/Repeat/Confirmation	—	Resolved
January 1, 2017	Arsenic	Maximum Contaminant Level Violation, Average	0.011 MG/L MCL 0.010 MG/L	Resolved
January 1, 2017	Arsenic	Maximum Contaminant Level Violation, Average	0.011 MG/L MCL 0.010 MG/L	Resolved
December 23, 2016	Public Notice	Public Notification Violation for NPDWR Violation	—	Addressed
October 1, 2016	Arsenic	Maximum Contaminant Level Violation, Average	0.011 MG/L MCL 0.010 MG/L	Resolved
October 1, 2016	Arsenic	Maximum Contaminant Level Violation, Average	0.011 MG/L MCL 0.010 MG/L	Resolved
July 1, 2016	Arsenic	Maximum Contaminant Level Violation, Average	0.011 MG/L MCL 0.010 MG/L	Resolved
July 1, 2016	Arsenic	Maximum Contaminant Level Violation, Average	0.011 MG/L MCL 0.010 MG/L	Resolved

Data from EPA SDWIS (violation records) , last refreshed May 24, 2026.

Where to see every contaminant this utility tested for

EPA's bulk SDWIS dataset gives MyTapWater.us per-system measured values for lead and copper, plus violation records for everything else. To see every regulated contaminant this utility tested for in the past year (TTHMs, HAA5, nitrate, arsenic, fluoride, chromium, etc.) with measured values, read the utility's Consumer Confidence Report (CCR).

Every community water system is required by EPA to publish a CCR annually, by July 1, listing every contaminant they sampled, the measured value, the federal limit, and any health-based exceedances. Most utilities post the report online; some mail it with your bill.

How to find TWIN LAKES RESORT's CCR:

Search the web for "TWIN LAKES RESORT consumer confidence report" . The PDF is usually on the utility's own website.
Or call the utility directly. Their phone number is in the contact section below.

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Contact this utility

Public administrative contact information for this water system, as filed with the EPA. Use this to ask about your service line, request your home's lead status, or report a water quality issue.

Administrator: GONZALEZ, GEORGINA
Phone: 619-283-6432
Email: lbtwinlakes@gmail.com
Mailing address: 7140 University Ave
Suite 102
LA MESA, CA 91942

Where this page's data comes from

Bundle released 2026-Q2, regenerated May 24, 2026. Each section above also shows its own source date so you can tell at a glance how fresh that part of the page is.

EPA SDWIS bulk download — last refreshed May 24, 2026 (system info, violations, lead and copper samples).
Lead service line inventory — last refreshed May 24, 2026 (from the utility's reported inventory).
CDC My Water's Fluoride — last refreshed May 19, 2026 (per-system Yes/No fluoridation status).
CDC Water Fluoridation Reporting System — last refreshed May 16, 2026 (state and county fluoridation aggregates).

Every value on this page is cross-verified before publication; read our methodology for the verification steps and corrections process.