Slide 2.   Wash-down water from dairy operations throughout Australia often directly or indirectly deliver high organic sediment, nutrient, and microorganism loads to natural receiving waters or to irrigation canals.  In this farm in Victoria, owned and operated by Chris and Ann Hunter, as is common, water is first held in an effluent pond for settling and some anaerobic digestion of organics.  However, effluent is also used to irrigate pasture and crop land.  Solids, nutrients, and organisms are seldom perfectly retained, and sometimes enter irrigation return flows or natural waters via runoff.  PAM has been tested successfully in the US and Australia to reduce movement in irrigation water of organic solids, nutrients and organisms.  Strategies for application of PAM technology to dairying, concentrated animal operations and pastures are the subject of current research interest for protection of surface and groundwater resources.