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RANCHO SANTA TERESA MW CO.

PWS ID: CA3700918 · RAMONA, California 92065

RANCHO SANTA TERESA MW CO. serves 102 people in RAMONA, California using Groundwater water sources. It has 186 recorded EPA violations, including 75 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: RANCHO SANTA TERESA MW CO.

RANCHO SANTA TERESA MW CO. is a private-owned community water system that delivers drinking water to 102 residents in RAMONA, California (San Diego County) through 38 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 186 total violations for this system , of which 75 (40%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 97 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Combined Uranium, recorded in 52 violations (MCL, health-based). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across California, EPA tracks 7,249 public water systems serving 42,404,883 people, with 153,308 cumulative violations and 63,983 health-based violations on record. About 89% of systems in the state carry at least one violation, and state-wide the average per system is 21.1 violations. RANCHO SANTA TERESA MW CO.'s 186 violations sit above the California average. Statewide, 447 of 694 UCMR5-tested systems have reported PFAS detections (64.4%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
102
Total Violations
186
Health-Based Violations
75
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
38
County
San Diego
School/Daycare
No
MCL Violations
75
Monitoring Violations
97
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Combined Uranium MCL 52 2019
Revised Total Coliform Rule MON 28 2022
Coliform (TCR) MCL 18 2015
Nitrate MR 18 2022
Nitrate MCL 5 2024
Coliform (TCR) MR 4 2009
Lead and Copper Rule MR 3 2021
1,2,4-Trichlorobenzene MR 2 2016
Xylenes, Total MR 2 2016
DICHLOROMETHANE MR 2 2016
o-Dichlorobenzene MR 2 2016
p-Dichlorobenzene MR 2 2016
1,1-Dichloroethylene MR 2 2016
1,2-Dichloroethane MR 2 2016
trans-1,2-Dichloroethylene MR 2 2016
1,1,1-Trichloroethane MR 2 2016
1,1,2-Trichloroethane MR 2 2016
Tetrachloroethylene MR 2 2016
Benzene MR 2 2016
Ethylbenzene MR 2 2016
Public Notice Other 2 2023
Gross Alpha, Excl. Radon and U MR 2 1981
Trichloroethylene MR 2 2016
Toluene MR 2 2016
Styrene MR 2 2016
CHLOROBENZENE MR 2 2016
Carbon tetrachloride MR 2 2016
Vinyl chloride MR 2 2016
1,2-Dichloropropane MR 2 2016
cis-1,2-Dichloroethylene MR 2 2016

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records — or to file a complaint, request a Consumer Confidence Report, or check current monitoring status — go directly to the federal and state regulators that enforce the Safe Drinking Water Act for RANCHO SANTA TERESA MW CO..

Federal Source of Truth

EPA SDWIS — Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID CA3700918 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

California Drinking Water Authority

California State Water Resources Control Board — Division of Drinking Water is the primacy agency that licenses and inspects RANCHO SANTA TERESA MW CO. under EPA-delegated authority.

Open CA regulator portal

Source: California State Water Resources Control Board — Division of Drinking Water

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2024 Nitrate MCL 5 SDWIS / CA3700918 / 1040
2023 Public Notice Other 2 SDWIS / CA3700918 / 7500
2022 Revised Total Coliform Rule MON 28 SDWIS / CA3700918 / 8000
2022 Nitrate MR 18 SDWIS / CA3700918 / 1040
2021 Lead and Copper Rule MR 3 SDWIS / CA3700918 / 5000
2019 Combined Uranium MCL 52 SDWIS / CA3700918 / 4006
2016 1,2,4-Trichlorobenzene MR 2 SDWIS / CA3700918 / 2378
2016 Xylenes, Total MR 2 SDWIS / CA3700918 / 2955
2016 DICHLOROMETHANE MR 2 SDWIS / CA3700918 / 2964
2016 o-Dichlorobenzene MR 2 SDWIS / CA3700918 / 2968
2016 p-Dichlorobenzene MR 2 SDWIS / CA3700918 / 2969
2016 1,1-Dichloroethylene MR 2 SDWIS / CA3700918 / 2977
2016 1,2-Dichloroethane MR 2 SDWIS / CA3700918 / 2980
2016 trans-1,2-Dichloroethylene MR 2 SDWIS / CA3700918 / 2979
2016 1,1,1-Trichloroethane MR 2 SDWIS / CA3700918 / 2981

How RANCHO SANTA TERESA MW CO. Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric RANCHO SANTA TERESA MW CO. California avg Federal benchmark
Total violations 186 21.1 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 75 8.8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 64.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 102 5,850 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 7,249 regulated public water systems in California.

Federal MCL reference — Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is RANCHO SANTA TERESA MW CO. water safe to drink? ▼
RANCHO SANTA TERESA MW CO. (PWS ID: CA3700918) has 186 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 102 people using Groundwater sources.
How many people does RANCHO SANTA TERESA MW CO. serve? ▼
RANCHO SANTA TERESA MW CO. serves 102 people in RAMONA, California. It is a Private-owned system using Groundwater water sources with 38 service connections.
What type of violations does RANCHO SANTA TERESA MW CO. have? ▼
RANCHO SANTA TERESA MW CO. has 186 total violations: 75 health-based violations (MCL exceedances or treatment failures), 97 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in RANCHO SANTA TERESA MW CO. water? ▼
No PFAS testing data is available for RANCHO SANTA TERESA MW CO. under the EPA's UCMR5 monitoring program.
What water source does RANCHO SANTA TERESA MW CO. use? ▼
RANCHO SANTA TERESA MW CO. uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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