LAND CAPABILITY ASSESSMENT FOR RECYCLED WATER IRRIGATION SCHEMES

摘要

Recycled water irrigation became common practice during the extended dry period from 1997 to 2009. The practice was recognised to be an alternative wastewater disposal strategy and was encouraged by state environment protection policies. These policies were given increased status by the need to control nutrient pollution of waterways in the mid-90s as a means of reducing the incidence of blue-green algae blooms.To provide assistance, government agencies prepared guidelines that specified acceptable and unacceptable levels of wastewater and soil parameters. Unfortunately these were sometimes used as "how to do manuals". Such guidelines, while useful, cannot eliminate the need for a thorough investigation of the site and careful analysis of the complex interactions that can occur in biological systems.The use of simple spreadsheet models that use readily available information, default values and "desk top" analyses without onsite investigations and ground-truthing can result in misleading results. There is no guarantee that this information is representative of a site or wastewater stream. Guidelines and manuals are no substitute for a systems approach based on a detailed investigation and the application of sound scientific and engineering principles.