1994-5: Mulwala (NSW) Murray River. Pesticide: Molinate

Molinate was the most commonly applied herbicide to rice crops in southern New South Wales in 1994-1995. It was detected in irrigation drains after application to rice fields at levels up to 0.7 mg/L (Bowmer et al 1998). Molinate was detected on two occasions in the Mulwala supply offtake on the Murray river, at 0.0072 and 0.0005 mg/L (7.2 and 0.5 μg/L). Over a 55-day period of monitoring supply water in the irrigated areas, molinate was found in 90% of the analysed samples, with a maximum concentration of 0.0036 mg/L (3.6 μg/L) (Bowmer et al 1998). The high frequency of molinate detection was due to samples being taken in early summer, when the herbicide is used in rice crops.