Nitrate In Drinking Water In New Hampshire
What residents of New Hampshire need to know about nitrate in drinking water — including how it enters water, which utilities have documented violations, and what steps to take.
Source: EPA SDWIS, New Hampshire Department of Environmental Services (NHDES), CDC · Last reviewed: 2025-01-01
Quick Answer
Is nitrate in drinking water a real concern in New Hampshire?
Moderate — New Hampshire has limited commercial agriculture. The primary nitrate concern is septic systems near private wells in suburban communities, particularly in areas with older or high-density septic infrastructure.
Is this mostly a public-water issue, a private-well issue, or both?
Primarily private well users in suburban communities with high septic system density; agricultural sources are limited compared to farming-intensive states.
What is the main reason residents should care?
New Hampshire's rural and suburban landscape has a high density of private wells and septic systems. Older or failing septic systems near wells are the dominant nitrate pathway, rather than agricultural sources.
Key Facts
| EPA Nitrate MCL | 10 mg/L as N |
| Primary source | Septic system effluent near private wells in suburban communities |
| Relative risk | Lower than agricultural states — limited commercial row-crop farming in NH |
| NHDES resources | Provides private well testing guidance and certified lab referrals |
| State oversight | New Hampshire Department of Environmental Services (NHDES) |
Why This Matters in New Hampshire
New Hampshire has limited commercial row-crop agriculture, which means the agricultural nitrate pathways common in Midwest states are less relevant. However, New Hampshire's many rural and suburban communities have high densities of private wells and septic systems. Older septic leach fields failing near shallow wells can elevate nitrate in private water sources. New Hampshire's granite bedrock produces naturally acidic groundwater, and some areas have shallow water tables that are more susceptible to surface contamination. NHDES monitors public water systems for nitrate compliance and provides private well testing guidance, including subsidized testing programs for some households.
Critical — Infants Under 6 Months
Do not use tap water that exceeds 10 mg/L nitrate-nitrogen to prepare infant formula or feed infants under six months. Boiling will concentrate nitrate — do not boil. Use bottled water or a certified reverse osmosis system (NSF/ANSI 58) until the issue is resolved.
New Hampshire Utilities With Nitrate Violation Records
The utilities listed below have at least one nitrate violation on record in EPA's SDWIS database. Violations may be open or resolved — see individual utility pages for current status and risk level.
How Nitrate Gets Into Drinking Water
Agricultural fertilizer and manure runoff
Nitrogen-based fertilizers and animal waste applied to New Hampshire cropland can leach into groundwater or run off into surface water supplies. This is the dominant nitrate pathway in most agricultural regions.
Septic system effluent
Failing or poorly sited septic systems release nitrogen-rich wastewater near drinking water wells. Rural areas with high well density and aging septic infrastructure face elevated risk.
Concentrated animal feeding operations (CAFOs)
Large livestock facilities generate significant waste. Lagoon leaks and overapplication of manure to nearby fields can create localized nitrate hotspots in groundwater.
Natural geological deposits
In some regions, naturally occurring nitrogen compounds in soil and bedrock contribute background nitrate levels to groundwater independent of agricultural activity.
Who Should Pay Closest Attention
Private well users in New Hampshire's suburban communities — particularly in communities with older septic systems, shallow water tables, or high septic density — should test for nitrate annually. NHDES provides resources on locating state-certified testing labs.
Households with infants under six months
Pregnant residents
Private well owners in agricultural areas
Households near livestock operations or CAFOs
Rural residents on shallow groundwater wells
Households with older or failing septic systems nearby
How to Check Your Situation in New Hampshire
- 1
Identify your water utility. Use the ZIP lookup below or browse the New Hampshire utility directory on this site.
- 2
Read your utility's page on this site to see its current risk level and any open nitrate violations.
- 3
Review your utility's most recent Consumer Confidence Report (CCR) — mailed annually or available on the utility's website. It must disclose any MCL exceedances.
- 4
If you are on a private well, arrange testing at a New Hampshire Department of Environmental Services (NHDES)-certified lab. Your state health department maintains a list of certified labs. Annual testing is recommended in agricultural areas.
- 5
If you have an infant under six months, use bottled water or a certified RO system (NSF/ANSI 58) immediately as a precautionary measure — do not wait for test results if you are in a high-risk area.
- 6
If your utility issues a nitrate exceedance notice, follow their guidance and do not use tap water for infants until the issue is resolved.
Treatment Options
Carbon filters and boiling do not remove nitrate. Only the options below are effective.
NSF/ANSI Standard 58 — Reverse Osmosis
RO systems certified to NSF/ANSI 58 reduce nitrate by 85–95% at the point of use. Under-sink installation required. The most practical residential option for nitrate concerns.
Distillation
Distillation units effectively remove nitrate along with most other dissolved contaminants. Suitable for drinking and cooking water — not whole-house use.
Anion Exchange
Ion exchange systems designed for nitrate removal exchange nitrate ions for chloride on a resin bed. Effective as a point-of-entry system; requires periodic regeneration and monitoring.
Carbon filters do NOT remove nitrate
Standard pitcher filters, faucet filters, and under-sink carbon units — including those certified NSF/ANSI 42 or 53 — do not remove nitrate. Do not use these for nitrate reduction.
Frequently Asked Questions
Related Pages
Nitrate — National Overview
All U.S. utilities with nitrate records
New Hampshire State Overview
All utilities and water quality data
Lead in Drinking Water
A separate but common concern
Reverse Osmosis Guide
Removes 85–95% of nitrate
Well Water Guide
Private well testing and safety
All Contaminants
Complete reference library
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.