The Commonwealth Government is in the process of developing a National Carp Control Plan (NCCP) that is examining options to control carp. One of the strategies being considered is the release of a variant of the Cyprinid Herpes Virus (CyHV-3). The plan is national but its primary focus is on the Murray-Darling Basin (MDB), where it is estimated that carp represent more than 80 percent of the total fish biomass. The River Murray provides between 40 to 90 percent of Adelaide’s water supply, with rural townships such as Renmark and Berri completely reliant on the river. This is also the case for numerous other rural towns in Victoria and New South Wales. If the virus is released and works effectively, the result will be a number of mass fish mortality events, which would be likely to have a substantial impact on water quality, depending on the nature of the clean-up operation. Preliminary research was conducted by SA Water to assess impacts to water quality from decomposing carp carcasses. The research had an emphasis on water quality parameters associated with water treatment, such as dissolved oxygen, pH, dissolved organic carbon (DOC), ammonia, alkalinity, suspended solids, FEEM (Fluorescence Excitation Emission Matrices; protein identification) and turbidity. There were six treatments which included four carp biomass loads of 0.2, 0.5, 2.0 and 5.0 kg m-3. The carp concentrations represented the range of uncertainty associated with published carp density estimates. The results from this study are presented and discussed in the perspective of treating contaminated water to an acceptable standard based on the Australian Drinking Water Guidelines and current water treatment technology.