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Community Water System · PWS MT0004873

Rainbow Estates

Bismarck, Montana 58501 - drinking water served from groundwater sources to 30 people, tracked in EPA SDWIS and UCMR5.

30
People served
909
EPA violations
6
Health-based
Untested
UCMR5 result

The verdict

EPA records 909 drinking-water violations at Rainbow Estates, 1% of them health-based - above the Montana per-system average.

909
Total EPA violations on record
1%
Health-based (MCL / treatment failure)
30
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Rainbow Estates

Rainbow Estates is a private-owned community water system that delivers drinking water to 30 residents in Bismarck, Montana (Dawson County) through 14 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 909 total violations for this system , of which 6 (1%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 893 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 Endrin, 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.

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%).

Rainbow Estates's 909 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
30
Total Violations
909
Health-Based Violations
6
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
14
County
Dawson
School/Daycare
No
MCL Violations
0
Monitoring Violations
893
Treatment Tech Violations
6

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Endrin MR 21 2020
Methoxychlor MR 21 2020
Toxaphene MR 21 2020
Dalapon MR 21 2020
Di(2-ethylhexyl) adipate MR 21 2020
OXAMYL MR 21 2020
Simazine MR 21 2020
Di(2-ethylhexyl) phthalate MR 21 2020
Dinoseb MR 21 2020
Carbofuran MR 21 2020
Atrazine MR 21 2020
LASSO MR 21 2020
Heptachlor MR 21 2020
Heptachlor epoxide MR 21 2020
2,4-D MR 21 2020
Benzo(a)pyrene MR 21 2020
Chlordane MR 21 2020
Hexachlorocyclopentadiene MR 21 2020
Pentachlorophenol MR 21 2020
2,4,5-TP MR 21 2020
BHC-GAMMA MR 21 2020
Picloram MR 21 2020
HEXACHLOROBENZENE MR 21 2020
1,2,4-Trichlorobenzene MR 18 2020
cis-1,2-Dichloroethylene MR 18 2020
Xylenes, Total MR 18 2020
DICHLOROMETHANE MR 18 2020
Vinyl chloride MR 18 2020
1,1-Dichloroethylene MR 18 2020
trans-1,2-Dichloroethylene MR 18 2020

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 Rainbow 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 MT0004873 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
2025 Consumer Confidence Rule Other 10 SDWIS / MT0004873 / 7000
2024 Lead and Copper Rule MR 10 SDWIS / MT0004873 / 5000
2023 E. COLI MR 6 SDWIS / MT0004873 / 3014
2023 Revised Total Coliform Rule TT 6 SDWIS / MT0004873 / 8000
2022 Nitrate-Nitrite MR 7 SDWIS / MT0004873 / 1038
2020 Endrin MR 21 SDWIS / MT0004873 / 2005
2020 Methoxychlor MR 21 SDWIS / MT0004873 / 2015
2020 Toxaphene MR 21 SDWIS / MT0004873 / 2020
2020 Dalapon MR 21 SDWIS / MT0004873 / 2031
2020 Di(2-ethylhexyl) adipate MR 21 SDWIS / MT0004873 / 2035
2020 OXAMYL MR 21 SDWIS / MT0004873 / 2036
2020 Simazine MR 21 SDWIS / MT0004873 / 2037
2020 Di(2-ethylhexyl) phthalate MR 21 SDWIS / MT0004873 / 2039
2020 Dinoseb MR 21 SDWIS / MT0004873 / 2041
2020 Carbofuran MR 21 SDWIS / MT0004873 / 2046

How Rainbow Estates Compares

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

Metric Rainbow Estates Montana avg Federal benchmark
Total violations 909 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 6 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 30 492 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 Rainbow Estates water safe to drink? ▼
Rainbow Estates (PWS ID: MT0004873) has 909 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 30 people using Groundwater sources.
How many people does Rainbow Estates serve? ▼
Rainbow Estates serves 30 people in Bismarck, Montana. It is a Private-owned system using Groundwater water sources with 14 service connections.
What type of violations does Rainbow Estates have? ▼
Rainbow Estates has 909 total violations: 6 health-based violations (MCL exceedances or treatment failures), 893 monitoring/reporting violations, and 6 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Rainbow Estates water? ▼
No PFAS testing data is available for Rainbow Estates under the EPA's UCMR5 monitoring program.
What water source does Rainbow Estates use? ▼
Rainbow 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.