The Onkaparinga Catchment Water Management Board (OCWMB) is responsible for an area of approx. 920 square km which includes the Onkaparinga Catchment in the Adelaide Hills and the Noarlunga and Willunga sedimentary embayments south of Adelaide, South Australia. Under the requirements of the South Australian Water Resources Act 1997, the OCWMB has prepared a five-year management plan to guide the management of water resources within its area. One of the goals of the management plan is to maintain and, if possible, enhance the quality of surface and groundwaters. The OCWMB has established a partnership with the Department for Water Resources to design an ongoing program to monitor the water quality within the shallow groundwater system throughout the catchment area. The objectives of the first stage of the program are to identify areas where the shallow groundwater aquifers are potentially threatened by point-source pollution, and to establish an ongoing sampling program to monitor changes in groundwater quality. Land-use activities such as unsewered residential areas, abattoirs, waste depots and wineries within the OCWMB area were selected as possible point-source pollution threats. The aquifer systems vary throughout the catchment, ranging from a fractured basement rock system dominating the northern and central areas to multiple sedimentary aquifer systems within the Noarlunga and Willunga Embayments. Using total well depth and aquifer type as criteria, existing shallow boreholes located down gradient of areas considered to be at risk were selected as potential sample points. Sampling commenced during March 2001 and analyte suites were tailored to measure contaminants expected from the targeted land uses.