Similar term(s): nitrite ion, nirtite compound.
Nitrate [NO3-]and nitrite [NO2-] are naturally occurring ions that are part of the nitrogen cycle. Nitrate is used mainly in inorganic fertilizers, and sodium nitrite is used as a food preservative, especially in cured meats. The nitrate concentration in groundwater and surface water is normally low but can reach high levels as a result of agricultural [activity and] runoff, refuse dump runoff, or contamination with human or animal wastes.
Source: Safe Water for International Travelers Water Quality Standards;
Nitrate
Chloramination may give rise to the formation of nitrite within the distribution system, and the concentration of nitrite may increase as the water moves towards the extremities of the system.
Chloramination - Inorganic - Metabolite - Water disinfection by-product(s)