IMPROVING THE QUALITY OF DRAINAGE WATER FROM NSW CANELANDS

THE NSW sugar industry after a 3.5 year SRDC/CRC Sugar funded study of surface water quality adjacent to canelands in north-east coastal NSW has emerged from having little direct awareness of physiochemical, nutrient and pesticide water quality in major drains adjacent to cane lands to a position of knowledge. The project targeted six of the many natural and constructed drains in the region, two in each of three mill areas (Condong; Tweed/Brunswick Catchments: Broadwater; Richmond Catchment: Harwood; Clarence Catchment). Automated water quality 'stations' were installed and maintained at the discharge end of the six main drains to continuously measure pH, electrical conductivity (EC), dissolved oxygen (DO), temperature, stream height and velocity. In addition, monthly water samples were collected close by and analysed onsite for DO and in a laboratory for suspended solids, pH, EC, chloride, nutrients (N and P) and pesticides (atrazine, diuron, 2,4-D, glyphosate, chlorpyrifos). Growers with farms adjacent to the drains operated as focus groups to discuss and respond progressively to the results from their respective drains, while a range of strategies were used during the study to inform other canegrowers and the wider community of the project's findings. The interactive nature of the study helped to raise awareness and change practices that subsequently led to measurable improvements in water quality, particularly for pesticide residues. There are sound reasons to establish locally relevant water quality criteria rather than to rely on generic guidelines that are different across the nearby state border with coastal south-east Queensland.