PlainWater
States → EPA Region 8 — Tribal Water Systems

Community Water System · PWS 085690004

Arapahoe Comm Water System

Ethete, EPA Region 8 — Tribal Water Systems 82520 - drinking water served from groundwater sources to 3,100 people, tracked in EPA SDWIS and UCMR5.

3,100
People served
585
EPA violations
22
Health-based
Untested
UCMR5 result

The verdict

EPA records 585 drinking-water violations at Arapahoe Comm Water System, 4% of them health-based.

585
Total EPA violations on record
4%
Health-based (MCL / treatment failure)
3,100
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Arapahoe Comm Water System

Arapahoe Comm Water System is a native american-owned community water system that delivers drinking water to 3,100 residents in Ethete, EPA Region 8 — Tribal Water Systems through 438 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 585 total violations for this system , of which 22 (4%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 553 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 21 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 8 — 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
3,100
Total Violations
585
Health-Based Violations
22
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Native American
Connections
438
School/Daycare
No
MCL Violations
21
Monitoring Violations
553
Treatment Tech Violations
1

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 21 2004
Coliform (TCR) MCL 21 2004
Nitrate-Nitrite MR 12 2019
Nitrate MR 11 2004
Benzene MR 9 2011
Carbon tetrachloride MR 9 2011
1,2-Dichloroethane MR 9 2011
1,1-Dichloroethylene MR 9 2011
Vinyl chloride MR 9 2011
cis-1,2-Dichloroethylene MR 9 2011
1,2-Dichloropropane MR 9 2011
Ethylbenzene MR 9 2011
CHLOROBENZENE MR 9 2011
o-Dichlorobenzene MR 9 2011
Styrene MR 9 2011
Tetrachloroethylene MR 9 2011
DICHLOROMETHANE MR 9 2011
trans-1,2-Dichloroethylene MR 9 2011
1,1,2-Trichloroethane MR 9 2011
1,2,4-Trichlorobenzene MR 9 2011
Trichloroethylene MR 9 2011
Toluene MR 9 2011
1,1,1-Trichloroethane MR 9 2011
Xylenes, Total MR 9 2011
p-Dichlorobenzene MR 9 2011
Endrin MR 8 2011
Toxaphene MR 8 2011
Diquat MR 8 2011
Endothall MR 8 2011
Glyphosate MR 8 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 Arapahoe Comm Water 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 085690004 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

EPA Region 8 — Tribal Water Systems Drinking Water Authority

EPA Region 8 — 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 08 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 E. COLI MR 1 SDWIS / 085690004 / 3014
2020 Gross Alpha, Excl. Radon and U MR 4 SDWIS / 085690004 / 4000
2020 Radium-226 MR 3 SDWIS / 085690004 / 4020
2020 Radium-228 MR 3 SDWIS / 085690004 / 4030
2020 Combined Uranium MR 3 SDWIS / 085690004 / 4006
2020 Revised Total Coliform Rule MON 1 SDWIS / 085690004 / 8000
2020 Combined Radium (-226 and -228) MR 1 SDWIS / 085690004 / 4010
2019 Nitrate-Nitrite MR 12 SDWIS / 085690004 / 1038
2017 TTHM MR 1 SDWIS / 085690004 / 2950
2017 Total Haloacetic Acids (HAA5) MR 1 SDWIS / 085690004 / 2456
2016 Groundwater Rule TT 1 SDWIS / 085690004 / 0700
2011 Benzene MR 9 SDWIS / 085690004 / 2990
2011 Carbon tetrachloride MR 9 SDWIS / 085690004 / 2982
2011 1,2-Dichloroethane MR 9 SDWIS / 085690004 / 2980
2011 1,1-Dichloroethylene MR 9 SDWIS / 085690004 / 2977

How Arapahoe Comm Water System Compares

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

Metric Arapahoe Comm Water System EPA Region 8 — Tribal Water Systems avg Federal benchmark
Total violations 585 - SDWA compliance, any non-zero count is a recorded breach
Health-based violations 22 - Indicates a contaminant exceeded a federal MCL
PFAS detection None - EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 3,100 - 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 8 — 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 Arapahoe Comm Water System water safe to drink? ▼
Arapahoe Comm Water System (PWS ID: 085690004) has 585 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 3,100 people using Groundwater sources.
How many people does Arapahoe Comm Water System serve? ▼
Arapahoe Comm Water System serves 3,100 people in Ethete, EPA Region 8 — Tribal Water Systems. It is a Native American-owned system using Groundwater water sources with 438 service connections.
What type of violations does Arapahoe Comm Water System have? ▼
Arapahoe Comm Water System has 585 total violations: 22 health-based violations (MCL exceedances or treatment failures), 553 monitoring/reporting violations, and 1 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Arapahoe Comm Water System water? ▼
No PFAS testing data is available for Arapahoe Comm Water System under the EPA's UCMR5 monitoring program.
What water source does Arapahoe Comm Water System use? ▼
Arapahoe Comm Water 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. 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.