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Community Water System · PWS NH1851010

Williamsburg

Nashua, New Hampshire 03064 - drinking water served from groundwater sources to 928 people, tracked in EPA SDWIS and UCMR5.

928
People served
46
EPA violations
0
Health-based
Untested
UCMR5 result

The verdict

EPA records 46 drinking-water violations at Williamsburg - below the New Hampshire per-system average.

46
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
928
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Williamsburg

Williamsburg is a private-owned community water system that delivers drinking water to 928 residents in Nashua, New Hampshire (Hillsborough County) through 371 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 46 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 46 monitoring and reporting violations are on file. The most recent violation on record dates to 2010.

The most frequently cited contaminant at this system is Nitrate, recorded in 2 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 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%).

Williamsburg's 46 violations sit below 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
928
Total Violations
46
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
371
County
Hillsborough
School/Daycare
No
MCL Violations
0
Monitoring Violations
46
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Nitrate MR 2 1993
Xylenes, Total MR 2 1993
p-Dichlorobenzene MR 2 1993
1,1-Dichloroethylene MR 2 1993
trans-1,2-Dichloroethylene MR 2 1993
1,2-Dichloroethane MR 2 1993
1,1,1-Trichloroethane MR 2 1993
1,2-Dichloropropane MR 2 1993
Trichloroethylene MR 2 1993
1,1,2-Trichloroethane MR 2 1993
Tetrachloroethylene MR 2 1993
CHLOROBENZENE MR 2 1993
Benzene MR 2 1993
Toluene MR 2 1993
Styrene MR 2 1993
1,2,4-Trichlorobenzene MR 2 1993
Chlorine MR 2 2010
cis-1,2-Dichloroethylene MR 2 1993
Carbon tetrachloride MR 2 1993
Ethylbenzene MR 2 1993
DICHLOROMETHANE MR 2 1993
Vinyl chloride MR 2 1993
o-Dichlorobenzene MR 2 1993

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 Williamsburg.

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 NH1851010 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
2010 Chlorine MR 2 SDWIS / NH1851010 / 0999
1993 Nitrate MR 2 SDWIS / NH1851010 / 1040
1993 Xylenes, Total MR 2 SDWIS / NH1851010 / 2955
1993 p-Dichlorobenzene MR 2 SDWIS / NH1851010 / 2969
1993 1,1-Dichloroethylene MR 2 SDWIS / NH1851010 / 2977
1993 trans-1,2-Dichloroethylene MR 2 SDWIS / NH1851010 / 2979
1993 1,2-Dichloroethane MR 2 SDWIS / NH1851010 / 2980
1993 1,1,1-Trichloroethane MR 2 SDWIS / NH1851010 / 2981
1993 1,2-Dichloropropane MR 2 SDWIS / NH1851010 / 2983
1993 Trichloroethylene MR 2 SDWIS / NH1851010 / 2984
1993 1,1,2-Trichloroethane MR 2 SDWIS / NH1851010 / 2985
1993 Tetrachloroethylene MR 2 SDWIS / NH1851010 / 2987
1993 CHLOROBENZENE MR 2 SDWIS / NH1851010 / 2989
1993 Benzene MR 2 SDWIS / NH1851010 / 2990
1993 Toluene MR 2 SDWIS / NH1851010 / 2991

How Williamsburg Compares

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

Metric Williamsburg New Hampshire avg Federal benchmark
Total violations 46 63.6 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 0 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 928 506 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 Williamsburg water safe to drink? ▼
Williamsburg (PWS ID: NH1851010) has 46 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 928 people using Groundwater sources.
How many people does Williamsburg serve? ▼
Williamsburg serves 928 people in Nashua, New Hampshire. It is a Private-owned system using Groundwater water sources with 371 service connections.
What type of violations does Williamsburg have? ▼
Williamsburg has 46 total violations: 0 health-based violations (MCL exceedances or treatment failures), 46 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Williamsburg water? ▼
No PFAS testing data is available for Williamsburg under the EPA's UCMR5 monitoring program.
What water source does Williamsburg use? ▼
Williamsburg 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.