However, high levels of turbidity may interfere with disinfection . If high turbidity were to interfere with disinfection, microbes could cause short-term effects, such as diarrhea, cramps, nausea, or headaches. Sodium and Hardness Although sodium and hardness do not have MCLs, they are of interest to many consumers who are concerned about sodium intake. Hardness is the sum of polyvalent cations present in the water, generally magnesium and calcium. The cations are usually naturally-occurring.
Sodium refers to the salt present in the water and is generally naturally occurring.