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States → EPA Region 9 — Tribal Water Systems

Community Water System · PWS 093500302

Rock Springs Community - NTUA

Fort Defiance, EPA Region 9 — Tribal Water Systems 86504 - drinking water served from groundwater sources to 1,574 people, tracked in EPA SDWIS and UCMR5.

1,574
People served
67
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 67 drinking-water violations at Rock Springs Community - NTUA.

67
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
1,574
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Rock Springs Community - NTUA

Rock Springs Community - NTUA is a native american-owned community water system that delivers drinking water to 1,574 residents in Fort Defiance, EPA Region 9 — Tribal Water Systems through 410 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 67 total violations for this system , of which 0 (0%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 38 monitoring and reporting violations are on file. The most recent violation on record dates to 2016.

The most frequently cited contaminant at this system is Toluene, recorded in 9 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
1,574
Total Violations
67
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Native American
Connections
410
School/Daycare
No
MCL Violations
0
Monitoring Violations
38
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Toluene MR 9 2016
Di(2-ethylhexyl) phthalate MR 5 2016
Coliform (TCR) MR 3 2015
Barium MR 2 2011
Thallium, Total MR 2 2011
Cadmium MR 1 2011
Chromium MR 1 2011
CYANIDE MR 1 2011
Mercury MR 1 2011
Selenium MR 1 2011
Antimony, Total MR 1 2011
Beryllium, Total MR 1 2011
Xylenes, Total MR 1 2001
Total Polychlorinated Biphenyls (PCB) MR 1 2001
DICHLOROMETHANE MR 1 2001
Combined Radium (-226 and -228) MR 1 2008
Total Haloacetic Acids (HAA5) MR 1 2014
TTHM MR 1 2014
Gross Alpha, Excl. Radon and U MR 1 2008
Arsenic MR 1 2011
Nitrate MR 1 2011
Consumer Confidence Rule Other 1 2002
Fluoride MR 1 2011

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 Rock Springs Community - NTUA.

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 093500302 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
2016 Toluene MR 9 SDWIS / 093500302 / 2991
2016 Di(2-ethylhexyl) phthalate MR 5 SDWIS / 093500302 / 2039
2015 Coliform (TCR) MR 3 SDWIS / 093500302 / 3100
2014 Total Haloacetic Acids (HAA5) MR 1 SDWIS / 093500302 / 2456
2014 TTHM MR 1 SDWIS / 093500302 / 2950
2011 Barium MR 2 SDWIS / 093500302 / 1010
2011 Thallium, Total MR 2 SDWIS / 093500302 / 1085
2011 Cadmium MR 1 SDWIS / 093500302 / 1015
2011 Chromium MR 1 SDWIS / 093500302 / 1020
2011 CYANIDE MR 1 SDWIS / 093500302 / 1024
2011 Mercury MR 1 SDWIS / 093500302 / 1035
2011 Selenium MR 1 SDWIS / 093500302 / 1045
2011 Antimony, Total MR 1 SDWIS / 093500302 / 1074
2011 Beryllium, Total MR 1 SDWIS / 093500302 / 1075
2011 Arsenic MR 1 SDWIS / 093500302 / 1005

How Rock Springs Community - NTUA Compares

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

Metric Rock Springs Community - NTUA EPA Region 9 — Tribal Water Systems avg Federal benchmark
Total violations 67 - SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 - Indicates a contaminant exceeded a federal MCL
PFAS detection None - EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 1,574 - 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 Rock Springs Community - NTUA water safe to drink? ▼
Rock Springs Community - NTUA (PWS ID: 093500302) has 67 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,574 people using Groundwater sources.
How many people does Rock Springs Community - NTUA serve? ▼
Rock Springs Community - NTUA serves 1,574 people in Fort Defiance, EPA Region 9 — Tribal Water Systems. It is a Native American-owned system using Groundwater water sources with 410 service connections.
What type of violations does Rock Springs Community - NTUA have? ▼
Rock Springs Community - NTUA has 67 total violations: 0 health-based violations (MCL exceedances or treatment failures), 38 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Rock Springs Community - NTUA water? ▼
No PFAS testing data is available for Rock Springs Community - NTUA under the EPA's UCMR5 monitoring program.
What water source does Rock Springs Community - NTUA use? ▼
Rock Springs Community - NTUA 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.