Ammoniacal Nitrogen Values for the Wairau Plain
Under anaerobic aquifer conditions nitrate nitrogen changes its form and is converted chemically to ammoniacal nitrogen (NH3+ and NH4+). Its presence is commonly associated with decomposing plant, animal and human waste or older, evolved groundwaters.
The distribution of ammoniacal nitrogen in the above figure clearly marks the edges of the main aquifer systems beneath the Wairau Plain at Riverlands, Rārangi and south of New Renwick Road. Several of the high values represent closed landfills rather than natural conditions, such as in the Taylor Pass area.
