During September 1995, the Australian Geological Survey Organisation and the Australian Institute of Marine Science took part in a joint survey aboard the 'Lady Basten' to monitor the dispersion, fates and effects of Produced Formation Water (PFW) discharged from the Harriet 'A' production platform on the North West Shelf.
The AGSO component of the work involved using Continuous Geochemical Tracer (CGT) analysis of specific light hydrocarbons (C1-C6, benzene and toluene) to map the shape and extent of the discharged PFW plume in surface waters at 2 m. depth.
Hydrographic parameters including water temperature, dissolved oxygen, pH, salinity and turbidity were also continuously profiled. Four hydrocarbon vertical profiles were completed at various distances from the platform and several surface water samples collected for isotopic analysis. The profIling was conducted at speeds of 2 to 8 knots resulting in a typical data-point spacing of 180 metres. A total of 993 line kilometres of geochemical and hydrographic data were collected during the survey period in a tidal range which varied from 1.5 to 3.0 metres.
