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States → EPA Region 9 — Tribal Water Systems

Community Water System · PWS 090600158

Viejas Community System

Alpine, EPA Region 9 — Tribal Water Systems 91901 - drinking water served from groundwater sources to 9,600 people, tracked in EPA SDWIS and UCMR5.

9,600
People served
181
EPA violations
3
Health-based
1 PFAS
UCMR5 result

The verdict

EPA records 181 drinking-water violations at Viejas Community System, 2% of them health-based, and UCMR5 testing detected 1 PFAS compound.

181
Total EPA violations on record
2%
Health-based (MCL / treatment failure)
9,600
People served by this system
1
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Viejas Community System

Viejas Community System is a native american-owned community water system that delivers drinking water to 9,600 residents in Alpine, EPA Region 9 — Tribal Water Systems through 230 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 181 total violations for this system , of which 3 (2%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 138 monitoring and reporting violations are on file. The most recent violation on record dates to 2008.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 17 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 24.3 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

EPA Region 9 — Tribal Water Systems has thousands of regulated public water systems tracked by EPA under the Safe Drinking Water Act.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
9,600
Total Violations
181
Health-Based Violations
3
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Native American
Connections
230
School/Daycare
No
MCL Violations
3
Monitoring Violations
138
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 17 2007
Nitrate MR 4 2007
CYANIDE MR 3 2005
ETHYLENE DIBROMIDE MR 3 2004
Coliform (TCR) MCL 3 2008
Lead and Copper Rule MR 3 2005
Arsenic MR 2 2005
Chromium MR 2 2005
Cadmium MR 2 2005
Fluoride MR 2 2005
Mercury MR 2 2005
Selenium MR 2 2005
Beryllium, Total MR 2 2005
Asbestos MR 2 1998
Endrin MR 2 1998
BHC-GAMMA MR 2 1998
Toxaphene MR 2 1998
Atrazine MR 2 1998
Heptachlor MR 2 1998
Heptachlor epoxide MR 2 1998
2,4-D MR 2 1998
2,4,5-TP MR 2 1998
Pentachlorophenol MR 2 1998
cis-1,2-Dichloroethylene MR 2 2004
Total Polychlorinated Biphenyls (PCB) MR 2 1998
1,2-DIBROMO-3-CHLOROPROPANE MR 2 1998
Xylenes, Total MR 2 2004
Chlordane MR 2 1998
o-Dichlorobenzene MR 2 2004
p-Dichlorobenzene MR 2 2004

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 116 samples detected PFAS.

Contaminant Date Result MRL Status
PFBS 6/4/2024 24.30 ppt 3.00 ppt Detected
PFOA 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFHpA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 6/4/2024 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 6/4/2024 <7.00 ppt 7.00 ppt Not Detected
PFTA 6/4/2024 <8.00 ppt 8.00 ppt Not Detected
PFHpS 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFPeS 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
NFDHA 6/4/2024 <20.00 ppt 20.00 ppt Not Detected
PFEESA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFMBA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFNA 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFMPA 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFHxS 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
4:2 FTS 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFBA 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
ADONA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 6/4/2024 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFUnA 6/4/2024 <2.00 ppt 2.00 ppt Not Detected
PFHxA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFDoA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFDA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFOS 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFPeA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFMPA 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFPeA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFMBA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFEESA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
NFDHA 6/4/2024 <20.00 ppt 20.00 ppt Not Detected
PFBA 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFHpS 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFNA 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFPeS 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
HFPO-DA 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
ADONA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 6/4/2024 <5.00 ppt 5.00 ppt Not Detected
PFHxA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFDoA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFDA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFOS 6/4/2024 <4.00 ppt 4.00 ppt Not Detected
PFHxS 6/4/2024 <3.00 ppt 3.00 ppt Not Detected
PFHpA 6/4/2024 <3.00 ppt 3.00 ppt Not Detected

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 Viejas Community System.

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 090600158 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

EPA Region 9 — Tribal Water Systems Drinking Water Authority

EPA Region 9 — Tribal Water Systems's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find 09 regulator via EPA SDWIS

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
2008 Coliform (TCR) MCL 3 SDWIS / 090600158 / 3100
2007 Coliform (TCR) MR 17 SDWIS / 090600158 / 3100
2007 Nitrate MR 4 SDWIS / 090600158 / 1040
2007 Total Haloacetic Acids (HAA5) MR 1 SDWIS / 090600158 / 2456
2005 CYANIDE MR 3 SDWIS / 090600158 / 1024
2005 Lead and Copper Rule MR 3 SDWIS / 090600158 / 5000
2005 Arsenic MR 2 SDWIS / 090600158 / 1005
2005 Chromium MR 2 SDWIS / 090600158 / 1020
2005 Cadmium MR 2 SDWIS / 090600158 / 1015
2005 Fluoride MR 2 SDWIS / 090600158 / 1025
2005 Mercury MR 2 SDWIS / 090600158 / 1035
2005 Selenium MR 2 SDWIS / 090600158 / 1045
2005 Beryllium, Total MR 2 SDWIS / 090600158 / 1075
2005 Barium MR 2 SDWIS / 090600158 / 1010
2005 Thallium, Total MR 2 SDWIS / 090600158 / 1085

How Viejas Community System Compares

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

Metric Viejas Community System EPA Region 9 — Tribal Water Systems avg Federal benchmark
Total violations 181 - SDWA compliance, any non-zero count is a recorded breach
Health-based violations 3 - Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound - EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 9,600 - Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across all regulated public water systems in EPA Region 9 — Tribal Water Systems.

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 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Viejas Community System water safe to drink? ▼
Viejas Community System (PWS ID: 090600158) has 181 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 9,600 people using Groundwater sources.
How many people does Viejas Community System serve? ▼
Viejas Community System serves 9,600 people in Alpine, EPA Region 9 — Tribal Water Systems. It is a Native American-owned system using Groundwater water sources with 230 service connections.
What type of violations does Viejas Community System have? ▼
Viejas Community System has 181 total violations: 3 health-based violations (MCL exceedances or treatment failures), 138 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Viejas Community System water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in Viejas Community System's water supply: PFBS. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Viejas Community System use? ▼
Viejas Community System 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.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

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

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.