Water Quality Standards

Chloride in drinking-water originates from natural sources, sewage and industrial effluents, urban run-off containing de-icing salt, and saline intrusion.
The main source of human exposure to chloride is the addition of salt to food, and the intake from this source is usually greatly in excess of that from drinking-water.
Excessive chloride concentrations increase rates of corrosion of metals in the distribution system, depending on the alkalinity of the water. This can lead to increased concentrations of metals in the supply.
No health-based guideline value is proposed for chloride in drinking-water. However, chloride concentrations in excess of about 250 mg/litre can give rise to detectable taste in water (see Acceptability aspects).