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Community Water System · PWS MT0004987

Hidden Valley Colony

Gildford, Montana 59525 - drinking water served from groundwater sources to 80 people, tracked in EPA SDWIS and UCMR5.

80
People served
156
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 156 drinking-water violations at Hidden Valley Colony - above the Montana per-system average.

156
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
80
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Hidden Valley Colony

Hidden Valley Colony is a private-owned community water system that delivers drinking water to 80 residents in Gildford, Montana (Hill County) through 2 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 156 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 154 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 Simazine, recorded in 6 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%).

Hidden Valley Colony's 156 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
80
Total Violations
156
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
2
County
Hill
School/Daycare
No
MCL Violations
0
Monitoring Violations
154
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Simazine MR 6 2019
Di(2-ethylhexyl) phthalate MR 6 2019
Picloram MR 6 2019
Hexachlorocyclopentadiene MR 6 2019
Atrazine MR 6 2019
Heptachlor MR 6 2019
Combined Radium (-226 and -228) MR 6 2019
2,4,5-TP MR 6 2019
Benzo(a)pyrene MR 6 2019
Pentachlorophenol MR 6 2019
Chlordane MR 6 2019
BHC-GAMMA MR 6 2019
Methoxychlor MR 6 2019
Endrin MR 6 2019
Dalapon MR 6 2019
Di(2-ethylhexyl) adipate MR 6 2019
OXAMYL MR 6 2019
Dinoseb MR 6 2019
Heptachlor epoxide MR 6 2019
2,4-D MR 6 2019
HEXACHLOROBENZENE MR 6 2019
Gross Alpha, Excl. Radon and U MR 6 2019
Toxaphene MR 6 2019
Carbofuran MR 6 2019
LASSO MR 6 2019
Nitrate-Nitrite MR 4 2024
Consumer Confidence Rule Other 2 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 Hidden Valley Colony.

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 MT0004987 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
2024 Nitrate-Nitrite MR 4 SDWIS / MT0004987 / 1038
2020 Consumer Confidence Rule Other 2 SDWIS / MT0004987 / 7000
2019 Simazine MR 6 SDWIS / MT0004987 / 2037
2019 Di(2-ethylhexyl) phthalate MR 6 SDWIS / MT0004987 / 2039
2019 Picloram MR 6 SDWIS / MT0004987 / 2040
2019 Hexachlorocyclopentadiene MR 6 SDWIS / MT0004987 / 2042
2019 Atrazine MR 6 SDWIS / MT0004987 / 2050
2019 Heptachlor MR 6 SDWIS / MT0004987 / 2065
2019 Combined Radium (-226 and -228) MR 6 SDWIS / MT0004987 / 4010
2019 2,4,5-TP MR 6 SDWIS / MT0004987 / 2110
2019 Benzo(a)pyrene MR 6 SDWIS / MT0004987 / 2306
2019 Pentachlorophenol MR 6 SDWIS / MT0004987 / 2326
2019 Chlordane MR 6 SDWIS / MT0004987 / 2959
2019 BHC-GAMMA MR 6 SDWIS / MT0004987 / 2010
2019 Methoxychlor MR 6 SDWIS / MT0004987 / 2015

How Hidden Valley Colony Compares

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

Metric Hidden Valley Colony Montana avg Federal benchmark
Total violations 156 131.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 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 80 492 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 Hidden Valley Colony water safe to drink? ▼
Hidden Valley Colony (PWS ID: MT0004987) has 156 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 80 people using Groundwater sources.
How many people does Hidden Valley Colony serve? ▼
Hidden Valley Colony serves 80 people in Gildford, Montana. It is a Private-owned system using Groundwater water sources with 2 service connections.
What type of violations does Hidden Valley Colony have? ▼
Hidden Valley Colony has 156 total violations: 0 health-based violations (MCL exceedances or treatment failures), 154 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Hidden Valley Colony water? ▼
No PFAS testing data is available for Hidden Valley Colony under the EPA's UCMR5 monitoring program.
What water source does Hidden Valley Colony use? ▼
Hidden Valley Colony 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.