Sodium & Chloride (Secondary Maximum Contaminant Levels 250 mg/l for each)
The compound known as "salt" consists of the elements sodium and chloride. Substantially higher levels of sodium and chloride tend to imply contamination by activities of man including road salt storage, use of road salts, and discharges from water softeners. Typical background levels of sodium and chloride for pristine locations in New Hampshire are generally less than 20 mg/L and 30 mg/L respectively.
EPA has not developed a health based drinking water standard for sodium intake from drinking water, as it is usually a minor source of exposure in the diet. The EPA has recommended that sodium levels not exceed 20mg/L for those people on a “no salt” diet. Since sodium and chloride can cause a salty taste to the water, secondary (or aesthetic) drinking water standards of have been developed by the EPA of 250 mg/L
For more information, please refer to the NH DES fact sheet:
WD-DWGB-3-17 Sodium and Chloride in Drinking Water