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Community Water System · PWS MT0004250

Oak Ridge Estates

Billings, Montana 59101 - drinking water served from groundwater sources to 200 people, tracked in EPA SDWIS and UCMR5.

200
People served
373
EPA violations
7
Health-based
Untested
UCMR5 result

The verdict

EPA records 373 drinking-water violations at Oak Ridge Estates, 2% of them health-based - above the Montana per-system average.

373
Total EPA violations on record
2%
Health-based (MCL / treatment failure)
200
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Oak Ridge Estates

Oak Ridge Estates is a private-owned community water system that delivers drinking water to 200 residents in Billings, Montana (Yellowstone County) through 81 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 373 total violations for this system , of which 7 (2%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 353 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 29 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Montana, EPA tracks 2,263 public water systems serving 1,112,267 people, with 297,270 cumulative violations and 25,922 health-based violations on record. About 95% of systems in the state carry at least one violation, and state-wide the average per system is 131.4 violations. Statewide, 28 of 45 UCMR5-tested systems have reported PFAS detections (62.2%).

Oak Ridge Estates's 373 violations sit above the Montana 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
200
Total Violations
373
Health-Based Violations
7
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
81
County
Yellowstone
School/Daycare
No
MCL Violations
7
Monitoring Violations
353
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Lead and Copper Rule MR 29 2014
TTHM MR 15 2006
Total Haloacetic Acids (HAA5) MR 15 2006
Coliform (TCR) MR 14 2006
1,2,4-Trichlorobenzene MR 13 2008
cis-1,2-Dichloroethylene MR 13 2008
DICHLOROMETHANE MR 13 2008
p-Dichlorobenzene MR 13 2008
Vinyl chloride MR 13 2008
1,1-Dichloroethylene MR 13 2008
trans-1,2-Dichloroethylene MR 13 2008
1,1,1-Trichloroethane MR 13 2008
Carbon tetrachloride MR 13 2008
1,2-Dichloropropane MR 13 2008
Trichloroethylene MR 13 2008
1,1,2-Trichloroethane MR 13 2008
Tetrachloroethylene MR 13 2008
CHLOROBENZENE MR 13 2008
Ethylbenzene MR 13 2008
o-Dichlorobenzene MR 13 2008
1,2-Dichloroethane MR 13 2008
Toluene MR 13 2008
Styrene MR 13 2008
Consumer Confidence Rule Other 13 2023
Xylenes, Total MR 13 2008
Benzene MR 13 2008
Nitrate-Nitrite MR 7 2003
Coliform (TCR) MCL 7 2005

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 Oak Ridge Estates.

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 MT0004250 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Montana Drinking Water Authority

Montana'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 MT 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
2023 Consumer Confidence Rule Other 13 SDWIS / MT0004250 / 7000
2014 Lead and Copper Rule MR 29 SDWIS / MT0004250 / 5000
2008 1,2,4-Trichlorobenzene MR 13 SDWIS / MT0004250 / 2378
2008 cis-1,2-Dichloroethylene MR 13 SDWIS / MT0004250 / 2380
2008 DICHLOROMETHANE MR 13 SDWIS / MT0004250 / 2964
2008 p-Dichlorobenzene MR 13 SDWIS / MT0004250 / 2969
2008 Vinyl chloride MR 13 SDWIS / MT0004250 / 2976
2008 1,1-Dichloroethylene MR 13 SDWIS / MT0004250 / 2977
2008 trans-1,2-Dichloroethylene MR 13 SDWIS / MT0004250 / 2979
2008 1,1,1-Trichloroethane MR 13 SDWIS / MT0004250 / 2981
2008 Carbon tetrachloride MR 13 SDWIS / MT0004250 / 2982
2008 1,2-Dichloropropane MR 13 SDWIS / MT0004250 / 2983
2008 Trichloroethylene MR 13 SDWIS / MT0004250 / 2984
2008 1,1,2-Trichloroethane MR 13 SDWIS / MT0004250 / 2985
2008 Tetrachloroethylene MR 13 SDWIS / MT0004250 / 2987

How Oak Ridge Estates Compares

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

Metric Oak Ridge Estates Montana avg Federal benchmark
Total violations 373 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 7 11.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 62.2% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 200 492 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,263 regulated public water systems in Montana.

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 Oak Ridge Estates water safe to drink? ▼
Oak Ridge Estates (PWS ID: MT0004250) has 373 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 200 people using Groundwater sources.
How many people does Oak Ridge Estates serve? ▼
Oak Ridge Estates serves 200 people in Billings, Montana. It is a Private-owned system using Groundwater water sources with 81 service connections.
What type of violations does Oak Ridge Estates have? ▼
Oak Ridge Estates has 373 total violations: 7 health-based violations (MCL exceedances or treatment failures), 353 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Oak Ridge Estates water? ▼
No PFAS testing data is available for Oak Ridge Estates under the EPA's UCMR5 monitoring program.
What water source does Oak Ridge Estates use? ▼
Oak Ridge Estates 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.