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Community Water System · PWS NN0436019

Seba Dalkai Boarding School BIA

Winslow, Navajo Nation 86047 - drinking water served from groundwater sources to 250 people, tracked in EPA SDWIS and UCMR5.

250
People served
191
EPA violations
97
Health-based
Untested
UCMR5 result

The verdict

EPA records 191 drinking-water violations at Seba Dalkai Boarding School BIA, 51% of them health-based - above the Navajo Nation per-system average.

191
Total EPA violations on record
51%
Health-based (MCL / treatment failure)
250
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Seba Dalkai Boarding School BIA

Seba Dalkai Boarding School BIA is a federal-owned community water system that delivers drinking water to 250 residents in Winslow, Navajo Nation through 20 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 191 total violations for this system , of which 97 (51%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 58 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is TTHM, recorded in 80 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 Navajo Nation, EPA tracks 170 public water systems serving 167,275 people, with 29,535 cumulative violations and 1,366 health-based violations on record. About 100% of systems in the state carry at least one violation, and state-wide the average per system is 173.7 violations. Statewide, 13 of 13 UCMR5-tested systems have reported PFAS detections (100%).

Seba Dalkai Boarding School BIA's 191 violations sit above the Navajo Nation average.

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
250
Total Violations
191
Health-Based Violations
97
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Federal
Connections
20
School/Daycare
Yes
MCL Violations
97
Monitoring Violations
58
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
TTHM MCL 80 2021
Coliform (TCR) MR 25 2012
Coliform (TCR) MCL 17 2012
TTHM MR 12 2022
Total Haloacetic Acids (HAA5) MR 12 2022
Public Notice Other 9 2021
Revised Total Coliform Rule RPT 4 2025
Lead and Copper Rule MR 4 2008
Revised Total Coliform Rule Other 3 2016
Stage 2 Disinfectants and Disinfection Byproducts Rule MR 3 2013
Revised Total Coliform Rule MON 2 2025

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 Seba Dalkai Boarding School BIA.

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 NN0436019 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Navajo Nation Drinking Water Authority

Navajo Nation'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 NN 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
2025 Revised Total Coliform Rule RPT 4 SDWIS / NN0436019 / 8000
2025 Revised Total Coliform Rule MON 2 SDWIS / NN0436019 / 8000
2022 TTHM MR 12 SDWIS / NN0436019 / 2950
2022 Total Haloacetic Acids (HAA5) MR 12 SDWIS / NN0436019 / 2456
2021 TTHM MCL 80 SDWIS / NN0436019 / 2950
2021 Public Notice Other 9 SDWIS / NN0436019 / 7500
2016 Revised Total Coliform Rule Other 3 SDWIS / NN0436019 / 8000
2013 Stage 2 Disinfectants and Disinfection Byproducts Rule MR 3 SDWIS / NN0436019 / 0600
2012 Coliform (TCR) MR 25 SDWIS / NN0436019 / 3100
2012 Coliform (TCR) MCL 17 SDWIS / NN0436019 / 3100
2008 Lead and Copper Rule MR 4 SDWIS / NN0436019 / 5000

How Seba Dalkai Boarding School BIA Compares

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

Metric Seba Dalkai Boarding School BIA Navajo Nation avg Federal benchmark
Total violations 191 173.7 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 97 8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 100% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 250 984 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 170 regulated public water systems in Navajo Nation.

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 Seba Dalkai Boarding School BIA water safe to drink? ▼
Seba Dalkai Boarding School BIA (PWS ID: NN0436019) has 191 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 250 people using Groundwater sources.
How many people does Seba Dalkai Boarding School BIA serve? ▼
Seba Dalkai Boarding School BIA serves 250 people in Winslow, Navajo Nation. It is a Federal-owned system using Groundwater water sources with 20 service connections.
What type of violations does Seba Dalkai Boarding School BIA have? ▼
Seba Dalkai Boarding School BIA has 191 total violations: 97 health-based violations (MCL exceedances or treatment failures), 58 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Seba Dalkai Boarding School BIA water? ▼
No PFAS testing data is available for Seba Dalkai Boarding School BIA under the EPA's UCMR5 monitoring program.
What water source does Seba Dalkai Boarding School BIA use? ▼
Seba Dalkai Boarding School BIA 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.