Well water testing in Rockingham County, New Hampshire

Last verified: 2026-10-25 · 7 sources · What we couldn't verify

Arsenic and radon are the big issues: in state lab data, 31% of Rockingham County wells tested were over 5 µg/L arsenic and 32% over the 2,000 pCi/L radon advisory. The state lab charges $95-$120 for its standard analysis and accepts overnight-mailed samples; NHDES offers free PFAS sampling for prioritized wells.

NHDES says private wells are the main drinking-water source for about 46% of New Hampshire's population (~520,000 people). There is no statewide testing or treatment requirement, but some towns require testing for a certificate of occupancy - in 2021 NHDES listed Derry, Salem, Windham and Chester (all Rockingham County towns) among them. Check with your town for current rules.^[2]

Free and low-cost testing programs

Labs that serve the county

NHDES's lab list was last updated 9/20/2024. Accreditation is per test, so confirm with NHDES's Accredited Laboratory Search (NHELAP: (603) 271-2998 / (603) 271-5314, nhelap@des.nh.gov) that a lab is accredited for every test you need.^[1]

Local contaminants of concern

• Major concern Arsenic. 31% of Rockingham County private wells tested at the state lab (2006 - Aug 2020) exceeded 0.005 mg/L (5 µg/L) arsenic, versus 25% statewide.^[2]
• Major concern Radon in water. 32% exceeded the 2,000 pCi/L radon testing advisory (30% statewide).^[2]
• Moderate concern Sodium and chloride (road salt). 55% exceeded 20 mg/L sodium (34% statewide) and 7% exceeded 250 mg/L chloride (3% statewide).^[2]
• Moderate concern Lead and copper (plumbing). In stagnant (first-draw) samples, 12% exceeded 0.015 mg/L lead and 10% exceeded 1.3 mg/L copper. Flushed samples: 1% for each.^[2]
• Moderate concern PFAS. NHDES says PFAS have affected private wells throughout New Hampshire, especially in the south, and recommends all private well owners test for PFAS (at minimum PFOA, PFOS, PFHxS and PFNA). No Rockingham-specific rate was found; see the NHDES PFAS Sampling Dashboard.^[5][1]
• Moderate concern Iron and manganese. 14% exceeded 0.3 mg/L iron and 6% exceeded 0.30 mg/L manganese.^[2]
• Lower concern Uranium. 4% exceeded the uranium limit (4% statewide). The source table prints the limit as "30 mg/L"; the EPA standard is 30 µg/L, so this is likely a units typo in the source.^[2]
• Lower concern Nitrate / nitrite and bacteria. 1% exceeded 10 mg/L nitrate and 0% exceeded 1 mg/L nitrite. No county bacteria rate was in the source; NHDES still recommends testing bacteria, nitrate and nitrite every year.^[2][1]

These are wells whose owners chose to test at the state lab (EPHT combined NHDES/NH Public Health Laboratories data set); private-lab results are not included.

A county rate can't tell you what's in your well. Only a test can. See what to test for.

Typical cost

Prices are from the published lists cited, as of the last-verified date. Confirm before ordering.

How often to test

• Every year: bacteria (total coliform and E. coli), nitrate and nitrite.^[1]
• Every 3-5 years: arsenic, chloride, copper and lead (stagnant and flushed), fluoride, hardness, iron, manganese, pH, radon, sodium, uranium, and PFAS (PFHxS, PFNA, PFOA, PFOS).^[1]
• PFAS: if a first test finds none and budget is tight, NHDES says waiting longer is acceptable if nearby land use does not change.^[1]
• Home buyers: test before buying if the seller has no recent test. After installing treatment: test treated water, then every 3-5 years.^[1]

How to collect a sample

Steps from the NH state lab's Standard Analysis kit (private labs have their own instructions):

1. If you recently disinfected the well, make sure all chlorine is gone. Use a clean indoor cold-water faucet that does not leak; do not touch the inside of bottles or caps.
2. Let water sit in the pipes at least 6 hours (overnight is best), then immediately fill the small "First Draw for Lead/Copper" bottle.
3. Remove the aerator if possible, clean the faucet rim with dilute bleach (1 capful per cup of water), and run the water for 1 minute.
4. At a gentle stream, fill the sterile bacteria, nitrate/nitrite and non-sterile bottles. For radon, slowly fill the glass vial to a crown, cap it, and check upside down for bubbles (refill if any).
5. Keep samples cold (not frozen) and deliver ASAP: bacteria within 30 hours, radon and nitrate/nitrite within 48 hours.

Source^[3]. General steps: How to test your well water.

After you get results

NHDES recommends entering your results into its Be Well Informed web tool for health information and the type of treatment that addresses each result, then contacting treatment vendors with that report.^[1][2]

What we couldn't verify

• Prices and mail-in policies for Eurofins Portsmouth, New England Radon and Seacoast Analytical Services.
• Whether Granite State Analytical accepts shipped samples (it offers online kit orders, drop-off and house calls).
• Current (2026) list of towns requiring well testing for occupancy - the source is a 2021 NHDES presentation.
• Rockingham-specific PFAS and bacteria rates.
• The NHDES guidance PDF (r1) blocks automated downloads; we read its text through a search-index copy, not a direct download.

Sources

1. NH Department of Environmental Services: Water Testing Guidance for Private Well Users (April 2026; lab list updated 9/20/2024)
2. B. Kernen, NHDES (hosted by City of Portsmouth): Private Wells in Portsmouth (presentation, Sept. 1, 2021; EPHT combined NHDES/NH PHL data 2006 - Aug 2020)
3. NH DHHS Public Health Laboratories: Water Test Submittal Form & Water Testing Guide / Sample Collection Instructions
4. NH DHHS: Water Analysis Laboratory Program
5. NHDES PFAS Response: Private Wells (PFAS testing)
6. NHDES PFAS Response: PFAS Removal Rebate Program for Private Wells
7. Granite State Analytical: Residential Services (test packages and prices)

All sources accessed on or before 2026-10-25.

More useful links

• NHDES private wells page (links to the Be Well Informed tool)

All New Hampshire county guides