Reed beds for the remediation and recycling of nursery runoff water

The water reform process of recent years has brought about dramatic regulatory changes regarding the access to, and pollution of, water resources in Australia. This has caused intensive irrigation users, such as the nursery and greenhouse industries, to look for ways of reducing both the quantity of water used and the discharge of nutrient-laden runoff to the environment. One of the simplest ways for nursery operators to achieve these two aims is to collect and recycle their irrigation runoff. Two issues that need to be overcome with this approach are: (i) the development of algal blooms in nutrient enriched storage dams, and (ii) the spread of plant diseases. A constructed wetland may provide a relatively inexpensive, low -maintenance solution to these problems. This article describes the findings of a three year monitoring study on the north coast of New South Wales into the use of subsurface flow constructed wetlands (reed beds) for the removal of nutrients and plant pathogens from nursery runoff. Suggestions for designing and constructing reed bed treatment systems for nursery irrigation runoff are also presented.