Sodium & Chloride

Sodium and chloride are very common in nature and can occur naturally at low levels in ground water. Sources such as road salt, fertilizers, sewage, water softener discharge and salt water intrusion in coastal environments can increase ground water concentrations significantly. The Maximum Contaminant Level (MCL) for chloride in Connecticut water supplies is 250 milligrams per liter (mg/L) and the notification level for sodium is 100 mg/L. While the chloride MCL is not health based, chloride is typically found with elevated sodium levels. Elevated levels of sodium, coupled with dietary intake, can potentially affect those on a sodium-restricted diet. Additionally, elevated levels of chloride and sodium can increase the corrosivity of the drinking water supply and may affect building plumbing.