HENNIKER, New Hampshire Tap Water Quality

3,921 people served · 4 water systems

Fair

HENNIKER, New Hampshire is a small town with 3,921 residents served by 4 public water systems. Water service covers ZIP code 03242.

HENNIKER has documented several EPA health-based violations in the last five years. Residents may want to review which contaminants triggered the exceedances and consider point-of-use filtration for sensitive uses.

EPA reporting identifies Fluoride among the regulated contaminants associated with HENNIKER's recent health-based violations. Each contaminant has different sources, health implications, and recommended mitigation steps — links to the full EPA reference for each are listed alongside the violation history below.

Last updated: 2026-05-18 · Source: EPA SDWIS

Location

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Centered on ZIP-code centroids of water systems serving this city.

ZIP Codes Served

03242

Health-Based Violations (Last 5 Years)

EPA Maximum Contaminant Level exceedances reported by water systems serving HENNIKER. Each entry explains the contaminant, the health risk, and recommended precautions, and links to a full guide.

Fluoridechemical

EPA Code 1025 · Maximum Contaminant Level Exceedance

violations

EPA Limit

4.0 mg/L

Last Reading

4.1 MG/L

First Reported

Jul 2022

Most Recent

Jul 2022

What this violation means

Fluoride at the optimal level (~0.7 mg/L) reduces tooth decay, which is why most US utilities add it. The MCL of 4.0 mg/L exists to protect against skeletal fluorosis from naturally high-fluoride groundwater, while the EPA's secondary standard of 2.0 mg/L addresses dental fluorosis in children.

Recommended precautions

→Reverse osmosis removes fluoride; standard carbon filters do NOT.
→If your child uses fluoride toothpaste and drinks fluoridated water, supervise brushing to limit ingestion.
→Bone meal supplements often contain fluoride and should be used cautiously.

Read the complete guide to Fluoride

Source: EPA Safe Drinking Water Information System (SDWIS). Health-based violations only. Older violations may have been resolved; check your utility's most recent Consumer Confidence Report for current status.

Water Systems Serving HENNIKER

WILSONS MHP

PWSID: NH0753010

30 served

EPSOM VILLAGE WATER DISTRICT

PWSID: NH0771010

800 served

WOOD HILL VILLAGE

PWSID: NH1123020

91 served

4 violations

COGSWELL SPRINGS WATER WORKS

PWSID: NH1121010

3,000 served

What Can You Do?

✅ Request your utility's annual Consumer Confidence Report (CCR) — required by law.
✅ Use an NSF-certified water filter if violations involve lead, arsenic, or PFAS.
✅ Run cold water for 30 seconds before drinking if you have older plumbing (reduces lead).
✅ Check back monthly — we update data from the EPA every 30 days.

About this data

This overview reflects EPA SDWIS data published as of 2026-05-18. It covers active Community Water Systems (CWS) that exceeded federal Maximum Contaminant Levels during the past five-year EPA reporting window. For up-to-the-minute information, request a current Consumer Confidence Report from your utility, or review the EPA's public dashboard.

Frequently Asked Questions

Is HENNIKER, New Hampshire tap water safe to drink?▼

This city's water had several EPA violations in the last 5 years.

How many EPA violations does HENNIKER have?▼

HENNIKER has 4 EPA health-based water violations in the last 5 years across 4 water systems serving 3,921 people.

What contaminants have been found in HENNIKER water?▼

The following EPA-regulated contaminants have been detected: 1025. View details about each contaminant, health effects, and recommended precautions above in the violations table.

Should I use a water filter in HENNIKER?▼

Using an NSF-certified water filter is recommended if your area has violations involving lead, arsenic, or PFAS. For other contaminants, consult your local water utility. Check the annual Consumer Confidence Report (CCR) for detailed guidance.

What should I do if there are violations in HENNIKER?▼

Request your water utility's annual Consumer Confidence Report (CCR), which is required by the EPA. Follow the utility's guidance on boil water advisories. Run cold water for 30 seconds before drinking if you have older plumbing. Use an NSF-certified filter if needed based on your water system's violations.