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States → New Hampshire

Community Water System · PWS NH0142010

Locke Lake

Nashua, New Hampshire 03064 - drinking water served from surface water sources to 2,278 people, tracked in EPA SDWIS and UCMR5.

2,278
People served
253
EPA violations
42
Health-based
Untested
UCMR5 result

The verdict

EPA records 253 drinking-water violations at Locke Lake, 17% of them health-based - above the New Hampshire per-system average.

253
Total EPA violations on record
17%
Health-based (MCL / treatment failure)
2,278
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Locke Lake

Locke Lake is a private-owned community water system that delivers drinking water to 2,278 residents in Nashua, New Hampshire (Belknap County) through 911 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 253 total violations for this system , of which 42 (17%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 208 monitoring and reporting violations are on file. The most recent violation on record dates to 2018.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 22 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. Statewide, 23 of 51 UCMR5-tested systems have reported PFAS detections (45.1%).

Locke Lake's 253 violations sit above the New Hampshire 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
2,278
Total Violations
253
Health-Based Violations
42
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Private
Connections
911
County
Belknap
School/Daycare
No
MCL Violations
42
Monitoring Violations
208
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 22 2012
Arsenic MCL 20 2018
Coliform (TCR) MR 12 2006
cis-1,2-Dichloroethylene MR 7 1995
DICHLOROMETHANE MR 7 1995
o-Dichlorobenzene MR 7 1995
1,1-Dichloroethylene MR 7 1995
trans-1,2-Dichloroethylene MR 7 1995
1,2-Dichloropropane MR 7 1995
1,1,2-Trichloroethane MR 7 1995
Nitrate MR 7 1995
1,1,1-Trichloroethane MR 7 1995
Carbon tetrachloride MR 7 1995
CHLOROBENZENE MR 7 1995
Benzene MR 7 1995
Ethylbenzene MR 7 1995
1,2-Dichloroethane MR 7 1995
p-Dichlorobenzene MR 7 1995
Toluene MR 7 1995
Trichloroethylene MR 7 1995
Vinyl chloride MR 7 1995
Styrene MR 7 1995
1,2,4-Trichlorobenzene MR 7 1995
Tetrachloroethylene MR 7 1995
Xylenes, Total MR 7 1995
Arsenic MR 3 1994
Cadmium MR 3 1994
Chromium MR 3 1994
CYANIDE MR 3 1994
Nickel MR 3 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 Locke Lake.

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 NH0142010 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
2018 Arsenic MCL 20 SDWIS / NH0142010 / 1005
2012 Coliform (TCR) MCL 22 SDWIS / NH0142010 / 3100
2012 E. COLI MR 2 SDWIS / NH0142010 / 3014
2010 Chlorine MR 2 SDWIS / NH0142010 / 0999
2006 Coliform (TCR) MR 12 SDWIS / NH0142010 / 3100
1995 cis-1,2-Dichloroethylene MR 7 SDWIS / NH0142010 / 2380
1995 DICHLOROMETHANE MR 7 SDWIS / NH0142010 / 2964
1995 o-Dichlorobenzene MR 7 SDWIS / NH0142010 / 2968
1995 1,1-Dichloroethylene MR 7 SDWIS / NH0142010 / 2977
1995 trans-1,2-Dichloroethylene MR 7 SDWIS / NH0142010 / 2979
1995 1,2-Dichloropropane MR 7 SDWIS / NH0142010 / 2983
1995 1,1,2-Trichloroethane MR 7 SDWIS / NH0142010 / 2985
1995 Nitrate MR 7 SDWIS / NH0142010 / 1040
1995 1,1,1-Trichloroethane MR 7 SDWIS / NH0142010 / 2981
1995 Carbon tetrachloride MR 7 SDWIS / NH0142010 / 2982

How Locke Lake Compares

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

Metric Locke Lake New Hampshire avg Federal benchmark
Total violations 253 63.6 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 42 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 2,278 506 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 (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 Locke Lake water safe to drink? ▼
Locke Lake (PWS ID: NH0142010) has 253 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 2,278 people using Surface Water sources.
How many people does Locke Lake serve? ▼
Locke Lake serves 2,278 people in Nashua, New Hampshire. It is a Private-owned system using Surface Water water sources with 911 service connections.
What type of violations does Locke Lake have? ▼
Locke Lake has 253 total violations: 42 health-based violations (MCL exceedances or treatment failures), 208 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Locke Lake water? ▼
No PFAS testing data is available for Locke Lake under the EPA's UCMR5 monitoring program.
What water source does Locke Lake use? ▼
Locke Lake uses Surface Water 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.