New Hampshire Tap Water Quality Rankings 2026: 12th in Nation | WaterQ
New Hampshire ranks 12th out of 50 states for drinking water quality, earning an overall grade of B with an average score of 88. The state's drinking water infrastructure serves a population of 797,358 across its 99 water systems. Although New Hampshire performs relatively well nationally, the state recorded 3,802 violations, suggesting areas that require regular oversight.
Key Findings for New Hampshire
Reviewing EPA SDWIS data for 2026, here's what defines New Hampshire's water quality landscape:
- Due to the region's characteristic granite bedrock geology, naturally occurring contaminants such as arsenic can dissolve into underground water sources supplying local wells.
- With many residents served by small rural water systems, monitoring and maintaining infrastructure can be more challenging than in large municipal networks.
- The forested New England landscape can lead to organic matter in surface water sources, which sometimes reacts with chlorine during treatment to form disinfection byproducts.
Most Common Contaminants in New Hampshire
Here's what New Hampshire residents should know about the contaminants most relevant to their water:
Arsenic
Naturally occurring arsenic is common in the granite bedrock geology of New Hampshire and can leach into groundwater aquifers. Exposure to elevated levels over time can pose health risks, making regular testing crucial for groundwater-sourced systems.
Disinfection Byproducts
When water systems treat surface water containing organic matter from forested watersheds with chlorine, disinfection byproducts can form. These chemical byproducts are monitored by the EPA to ensure they remain within safe limits.
Lead
While lead rarely occurs naturally in source water, it can leach into drinking water from older plumbing fixtures or service lines. This is a common issue in older housing stock throughout New England.
New Hampshire's Best and Worst Cities for Water Quality
To see the specific water testing results and violation histories for individual municipalities across the state, please explore the detailed city-by-city breakdown on our New Hampshire state page. This data helps residents track the performance of their local utility provider. Explore the full breakdown on our New Hampshire water systems page.
What New Hampshire Residents Should Do
Given New Hampshire's 12th place ranking, here's what matters most for residents:
- Look up your local water utility's consumer confidence report (CCR) and search its historical EPA violation record.
- If your household relies on a private well, schedule regular testing for naturally occurring minerals like arsenic and common bacteria.
- Consider installing a certified water filtration system tailored to target the specific contaminants identified in your area.
- Check your home's internal plumbing for lead solder or brass fixtures, especially if your house was built before 1986.
Frequently Asked Questions
How does New Hampshire water quality compare to other states?
New Hampshire ranks 12th out of 50 states for drinking water quality. It holds an overall grade of B with an average score of 88, placing it in the upper tier of states nationwide. However, the state still recorded 3,802 violations across its 99 water systems, indicating room for local improvement.
What are the most common contaminants in New Hampshire tap water?
Common concerns in the region include naturally occurring arsenic leaching from the granite bedrock geology and disinfection byproducts formed when organic matter from forested areas reacts with treatment chemicals. Lead can also be a concern due to older plumbing infrastructure in residential areas.
Is it safe to drink tap water in New Hampshire?
Generally, yes, as New Hampshire receives a solid B grade, indicating relatively good water quality across most of its systems. However, with 3,802 registered violations, residents should verify their local utility's performance and consider testing if using a private well.
Source: EPA SDWIS 2026 Compliance Data and WaterQ National Database. For more information on our ranking process, visit our state rankings page.