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States → EPA Region 9 — Tribal Water Systems

Community Water System · PWS 090400242

SCUA Upper Peridot

San Carlos, EPA Region 9 — Tribal Water Systems 85550 - drinking water served from groundwater sources to 275 people, tracked in EPA SDWIS and UCMR5.

275
People served
404
EPA violations
4
Health-based
Untested
UCMR5 result

The verdict

EPA records 404 drinking-water violations at SCUA Upper Peridot, 1% of them health-based.

404
Total EPA violations on record
1%
Health-based (MCL / treatment failure)
275
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: SCUA Upper Peridot

SCUA Upper Peridot is a native american-owned community water system that delivers drinking water to 275 residents in San Carlos, EPA Region 9 — Tribal Water Systems through 106 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 404 total violations for this system , of which 4 (1%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 300 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 Coliform (TCR), recorded in 102 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

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.

Population Served
275
Total Violations
404
Health-Based Violations
4
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Native American
Connections
106
School/Daycare
No
MCL Violations
2
Monitoring Violations
300
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 102 2016
Consumer Confidence Rule Other 15 2022
Lead and Copper Rule MR 13 2011
Arsenic MR 11 2011
Nitrate MR 10 2022
Revised Total Coliform Rule RPT 10 2023
E. COLI MR 6 2019
Total Polychlorinated Biphenyls (PCB) MR 4 2004
1,2-DIBROMO-3-CHLOROPROPANE MR 4 2004
Cadmium MR 3 2004
Chromium MR 3 2004
CYANIDE MR 3 2008
Fluoride MR 3 2004
Mercury MR 3 2004
Selenium MR 3 2004
BHC-GAMMA MR 3 2004
Methoxychlor MR 3 2004
Toxaphene MR 3 2004
Carbofuran MR 3 2004
Atrazine MR 3 2004
LASSO MR 3 2004
Heptachlor MR 3 2004
Heptachlor epoxide MR 3 2004
2,4-D MR 3 2004
2,4,5-TP MR 3 2004
Pentachlorophenol MR 3 2004
1,2,4-Trichlorobenzene MR 3 2004
cis-1,2-Dichloroethylene MR 3 2004
ETHYLENE DIBROMIDE MR 3 2004
DICHLOROMETHANE MR 3 2004

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 SCUA Upper Peridot.

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 090400242 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
2024 Public Notice Other 2 SDWIS / 090400242 / 7500
2024 Groundwater Rule TT 2 SDWIS / 090400242 / 0700
2024 LEAD AND COPPER RULE REVISIONS RPT 2 SDWIS / 090400242 / 5200
2023 Revised Total Coliform Rule RPT 10 SDWIS / 090400242 / 8000
2022 Consumer Confidence Rule Other 15 SDWIS / 090400242 / 7000
2022 Nitrate MR 10 SDWIS / 090400242 / 1040
2019 E. COLI MR 6 SDWIS / 090400242 / 3014
2016 Coliform (TCR) MR 102 SDWIS / 090400242 / 3100
2011 Lead and Copper Rule MR 13 SDWIS / 090400242 / 5000
2011 Arsenic MR 11 SDWIS / 090400242 / 1005
2008 CYANIDE MR 3 SDWIS / 090400242 / 1024
2007 Gross Alpha, Excl. Radon and U MR 2 SDWIS / 090400242 / 4000
2007 Combined Uranium MR 1 SDWIS / 090400242 / 4006
2007 Combined Radium (-226 and -228) MR 1 SDWIS / 090400242 / 4010
2004 Total Polychlorinated Biphenyls (PCB) MR 4 SDWIS / 090400242 / 2383

How SCUA Upper Peridot Compares

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

Metric SCUA Upper Peridot EPA Region 9 — Tribal Water Systems avg Federal benchmark
Total violations 404 - SDWA compliance, any non-zero count is a recorded breach
Health-based violations 4 - Indicates a contaminant exceeded a federal MCL
PFAS detection None - EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 275 - 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 SCUA Upper Peridot water safe to drink? ▼
SCUA Upper Peridot (PWS ID: 090400242) has 404 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 275 people using Groundwater sources.
How many people does SCUA Upper Peridot serve? ▼
SCUA Upper Peridot serves 275 people in San Carlos, EPA Region 9 — Tribal Water Systems. It is a Native American-owned system using Groundwater water sources with 106 service connections.
What type of violations does SCUA Upper Peridot have? ▼
SCUA Upper Peridot has 404 total violations: 4 health-based violations (MCL exceedances or treatment failures), 300 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in SCUA Upper Peridot water? ▼
No PFAS testing data is available for SCUA Upper Peridot under the EPA's UCMR5 monitoring program.
What water source does SCUA Upper Peridot use? ▼
SCUA Upper Peridot 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. 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.