“Jiwan and Riley (1993) detected atrazine in around 6% of groundwater samples at five sites in alluvial aquifers under the Liverpool Plains in the north-west of NSW. In the lower Namoi Valley, atrazine concentrations from less than 0.1 to 5.8ug/L were found in groundwater (Boey & Cooper 1996). The most vulnerable sites for ground water contamination by atrazine are often in floodplain areas where shallow perched water tables exist (Boey & Cooper 1996)”.
Source: p134 Pesticide Use in Australia. A Review Undertaken by the Australian Academy of Technological Sciences and Engineering.