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HIDDEN VALLEY/MASON

PWS ID: NH2372020 · MOULTONBOROUGH, New Hampshire 03254

HIDDEN VALLEY/MASON serves 298 people in MOULTONBOROUGH, New Hampshire using Groundwater water sources. It has 121 recorded EPA violations, including 15 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: HIDDEN VALLEY/MASON

HIDDEN VALLEY/MASON is a private-owned community water system that delivers drinking water to 298 residents in MOULTONBOROUGH, New Hampshire (Carroll County) through 119 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 121 total violations for this system , of which 15 (12%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 101 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 11 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 New Hampshire, EPA tracks 2,453 public water systems serving 1,242,123 people, with 155,970 cumulative violations and 29,649 health-based violations on record. About 90% of systems in the state carry at least one violation, and state-wide the average per system is 63.6 violations. HIDDEN VALLEY/MASON's 121 violations sit above the New Hampshire average. Statewide, 23 of 51 UCMR5-tested systems have reported PFAS detections (45.1%). 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
298
Total Violations
121
Health-Based Violations
15
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
119
County
Carroll
School/Daycare
No
MCL Violations
11
Monitoring Violations
101
Treatment Tech Violations
4

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 11 2011
Nitrite MR 5 1996
Revised Total Coliform Rule RPT 4 2016
Revised Total Coliform Rule TT 4 2016
Lead and Copper Rule MR 2 2024
Nitrate MR 2 1994
1,2,4-Trichlorobenzene MR 2 1994
Endrin MR 2 1994
cis-1,2-Dichloroethylene MR 2 1994
BHC-GAMMA MR 2 1994
Xylenes, Total MR 2 1994
Methoxychlor MR 2 1994
DICHLOROMETHANE MR 2 1994
Toxaphene MR 2 1994
Glyphosate MR 2 1994
Vinyl chloride MR 2 1994
1,1-Dichloroethylene MR 2 1994
Simazine MR 2 1994
trans-1,2-Dichloroethylene MR 2 1994
Di(2-ethylhexyl) phthalate MR 2 1994
1,2-Dichloroethane MR 2 1994
Carbon tetrachloride MR 2 1994
Hexachlorocyclopentadiene MR 2 1994
1,2-Dichloropropane MR 2 1994
Carbofuran MR 2 1994
Trichloroethylene MR 2 1994
1,1,2-Trichloroethane MR 2 1994
LASSO MR 2 1994
Benzene MR 2 1994
2,4-D MR 2 1994

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/MASON.

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 NH2372020 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

New Hampshire Drinking Water Authority

New Hampshire'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 NH 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 Lead and Copper Rule MR 2 SDWIS / NH2372020 / 5000
2016 Revised Total Coliform Rule RPT 4 SDWIS / NH2372020 / 8000
2016 Revised Total Coliform Rule TT 4 SDWIS / NH2372020 / 8000
2011 Coliform (TCR) MCL 11 SDWIS / NH2372020 / 3100
1996 Nitrite MR 5 SDWIS / NH2372020 / 1041
1994 Nitrate MR 2 SDWIS / NH2372020 / 1040
1994 1,2,4-Trichlorobenzene MR 2 SDWIS / NH2372020 / 2378
1994 Endrin MR 2 SDWIS / NH2372020 / 2005
1994 cis-1,2-Dichloroethylene MR 2 SDWIS / NH2372020 / 2380
1994 BHC-GAMMA MR 2 SDWIS / NH2372020 / 2010
1994 Xylenes, Total MR 2 SDWIS / NH2372020 / 2955
1994 Methoxychlor MR 2 SDWIS / NH2372020 / 2015
1994 DICHLOROMETHANE MR 2 SDWIS / NH2372020 / 2964
1994 Toxaphene MR 2 SDWIS / NH2372020 / 2020
1994 Glyphosate MR 2 SDWIS / NH2372020 / 2034

How HIDDEN VALLEY/MASON Compares

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

Metric HIDDEN VALLEY/MASON New Hampshire avg Federal benchmark
Total violations 121 63.6 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 15 12.1 Indicates a contaminant exceeded a federal MCL
PFAS detection None 45.1% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 298 506 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,453 regulated public water systems in New Hampshire.

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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is HIDDEN VALLEY/MASON water safe to drink? ▼
HIDDEN VALLEY/MASON (PWS ID: NH2372020) has 121 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 298 people using Groundwater sources.
How many people does HIDDEN VALLEY/MASON serve? ▼
HIDDEN VALLEY/MASON serves 298 people in MOULTONBOROUGH, New Hampshire. It is a Private-owned system using Groundwater water sources with 119 service connections.
What type of violations does HIDDEN VALLEY/MASON have? ▼
HIDDEN VALLEY/MASON has 121 total violations: 15 health-based violations (MCL exceedances or treatment failures), 101 monitoring/reporting violations, and 4 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in HIDDEN VALLEY/MASON water? ▼
No PFAS testing data is available for HIDDEN VALLEY/MASON under the EPA's UCMR5 monitoring program.
What water source does HIDDEN VALLEY/MASON use? ▼
HIDDEN VALLEY/MASON 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.

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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.

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