The New Hampshire Department of Environmental Services, (NHDES), recommends that private wells are tested every three to five year for Arsenic, Chloride, Copper, Fluoride, Hardness, Iron, Lead, Manganese, pH, and Sodium. They recommend wells to be tested every year for bacteria and nitrates. There are more stringent testing requirements for public water supplies.

NHDES has developed fact sheets about different contaminants. Use the below links to retrieve information about the contaminant you’re looking for:

ArsenicArsenic in New Hampshire Well Water – NHDES Factsheet WD-DWGB  3-2

The EPA enforceable MCL (Maximum Contamination Level) for Arsenic is of 10 parts per billion (ppb, ug/l). In New Hampshire, drilled wells have about a 20% probability of having a concentration higher than that, especially in the NH seacoast area.  Arsenic has no smell or taste, so the only way to know what level is in your water is to have it tested at an accredited laboratory such as Seacoast Analytical Services.

Sodium and Chloride:   Sodium and Chloride in Drinking Water – NHDES Factsheet WD-DWGB 3-17

There are currently no health-based standards (primary drinking water standards) for sodium or chloride under the Federal Safe Drinking Water Act. However, the EPA and the American Heart Association recommends sodium levels 20 mg/L for people whose doctors prescribe a “no salt diet.”

Fluoride: Flouride in Drinking Water – NHDES Factsheet WD-DWBG 3-5

The CDC recommends a concentration of less than 1.1 mg/l for New Hampshire residents. [1.1 mg/L is the same as 1.1 parts per million parts (ppm)].

Hardness Hardness in Drinking Water  NHDES Factsheet WD-DWGB 3-6

The simple definition of water hardness is the amount of dissolved calcium and magnesium in the water. Hard water is high in dissolved minerals, both calcium and magnesium. Hardness is not harmful to you, but you may want to treat for it so it does not cause problems with scaling in your plumbing fixtures. 

Iron and/or Manganese Iron and Manganese in Drinking Water – NHDES Factsheet WD-DWGB 3-8

Although concentrations in NH’s drinking water is found not to be harmful to your health, many people opt to treat for iron and manganese due to staining and other unpleasant aesthetic issues.

Nitrate/Nitrite Nitrate and Nitrite in Drinking Water – NHDES Factsheet WD-DWGB 3-9

Nitrates and nitrites are chemical compounds that naturally occur in soil, water, plants, and the human body. Nitrate is found in inorganic fertilizers and nitrite can be found in cured meats. Nitrites in your water is very dangerous, especially if ingested by infants.


If you want to get your water tested, please contact Seacoast Analytical Services or our Epping office at 603-679-5299.