High nitrates in freshwaters from intensive agriculture are a problem all around the world. ESR, New Zealand are reducing high nitrate levels in shallow groundwater before the groundwater discharges to, and impacts, streams and rivers. They are using a denitrifying wood chip permeable wall, which is widely used in fine-grain groundwater systems and evaluating how it can be applied in a very fast-flowing, heterogeneous alluvial gravel aquifer. These aquifers are widespread through NZ, are economically important with large volumes of groundwater used for irrigation and food processing, but are vulnerable to contamination by nitrate.

свернуть