Phase II/V (Nitrate/Nitrite, Inorganics, Organics)
Nitrates and nitrites are nitrogen-oxygen chemical units that combine with various organic and inorganic compounds. They come from the breakdown of nitrogen compounds in the soil, where flowing ground water picks them up. High levels of nitrates and nitrites in groundwater are usually due to human activities but can sometimes be found naturally in groundwater. The major sources of nitrates and nitrites in drinking water are runoff from fertilizer use, sewage – especially leakage from septic tanks – and erosion of natural deposits.