Bowmer et al. (1995) reviewed and reported on the pesticide monitoring that has been carried out in these irrigation areas. Supply water from the rivers was of high quality and generally few pesticides were detected. Just a few channels contained low levels of atrazine (0.08ug/L & 0.2 ug/L); endosulfan sulphate (0.02ug/L); molinate (7.2 ug/L & 0.5 ug/L); and 2,4-D (0.5 ug/L). Water supplying farms in the Willbriggie district, which had been mixed with MIA drainage water, contained higher concentrations of some pesticides and more frequent detections. Molinate was detected in 90% of samples over 55-days in spring and early summer, up to a maximum concentration of 3.6ug/L and atrazine in 20% of samples, up to 0.35ug/L.
Source: P129 Pesticide Use in Australia. A Review Undertaken by the Australian Academy of Technological Sciences and Engineering.