Chloride is usually ingested as sodium chloride (common salt). The contribution to the diet from drinking water is, therefore, small in comparison. Chloride has high electrical conductivity and will greatly increase the aggressiveness of the water towards metals. Localised pinholing of metals due to corrosion can occur with very high concentrations of chloride. High chloride levels can, therefore, lead to increased metal concentrations in water as a result of corrosion.
High chloride concentrations can have an effect on the taste of drinking water and levels are set with this in mind.