Usually RO Treatment would ...

Usually RO Treatment would work in this situation or bioremediation methods with denitrification using aerobic bacteria but we would need to know the influent level and the effluent target to provide the best water treatment system in this case. Do you know what the source of the elevated Nitrogen is in the borehole? Source control is very important when it comes to elevated Nitrogen levels to prevent eutrophication or excess nutrient enrichment for receiving waterbodies that cause dissolved oxygen to be depleted and cause massive fish kills and public health impacts with such water impairment. Prevention is always the best method!