Use a home distillation system to filter nitrates out of drinking water. Distillers boil the water and collect the steam, which is safe to drink because nitrates and mineral contaminants stay in the boiling tank.
Filter drinking water with a reverse-osmosis filter. These filters use high pressure to force the water through a thin polyimide membrane, which collects and blocks the contaminated water and releases clean water.
Remove nitrates with an ion exchange filter. Ion exchange filters are the most efficient, because they don't use much energy. Ion exchange filters work by adsorption, a chemical process in which nitrate ions adhere to beads of resin that have been charged with chloride. The nitrate ions are exchanged for the chloride ions.