Sodium and Chloride in Household Drinking Water
Sodium and chloride, which together compose common table salt, often occur naturally in groundwater as it dissolves minerals underground. Higher levels of sodium and chloride in household water, however, often come from manmade sources such as road salt, industrial wastes, sewage, fertilizers, or water softeners. In coastal areas, sodium and chloride can also enter groundwater via salt water intrusion into fresh water aquifers. In high enough concentrations, salt water intrusion can render groundwater unsuitable for drinking, cooking, or irrigating.