In recent years considerable progress has been made on quantifying the impacts on groundwater quality of various point and diffuse sources of contamination associated with Australian rural industries, In extensive industries, the effects of grazing, clearing native vegetation, fertilisers, and pesticides are understood in some areas where research has been undertaken; and the paper summarises some of the research results, For intensive rural industries, such as feedlots, piggeries, dairies and cheese factories, waste management is the key to groundwater quality protection. Observations on the sources of contaminants and their fate in groundwater are described. The increasing intensity of rural production, shown by the rapid expansion of beef feedlots, growth in the area of irrigation within the dairy industry, and accelerating sales of nitrogenous fertilisers indicate that the risk of contamination of groundwater resources is increasing, and the effectiveness of protection strategies will be challenged. A sound basis is needed and in progress of being developed to address point and diffuse sources in perspective within a region.