This frontier study investigated the timely development of pulsed ultraviolet light (PUV) and pulsed-plasma gas-discharge (PPGD) technologies for the destruction of harmful Cryptosporidium oocysts and other problematical microorganisms in water. This constitutes the first study to report on the use of these pulsed power electrotechnologies (PPET) for the destruction of chlorine resistant Cryptosporidium oocysts, which have caused waterborne illness outbreaks worldwide. By accumulating energy over relatively long time periods, and by dissipating this energy in ultrashort pulses, the energy remains constant thus offering a radically new approach to energy delivery that have been shown to be orders of magnitude more efficient compared to using conventional decontamination approaches. Critical inter-related factors affecting the effective and repeatable decontamination performance of PUV and PPGD were identified during this study. The PUV approach proved superior to the PPGD system for treating similar artificially spiked samples in water, which is a positive finding considering the fact that commensurate toxicological investigations carried out in this study revealed that PPGD-treated water produced unwanted toxic end-points. This innovative, technology-driven, project generated critical data that will narrow the gap between the underpinning science/engineering and operational use in future scaled-up water treatment plant studies. It will add considerably to critical data facilitating microbiological predictive modeling and will also impact positively on public health by safeguarding water quality and supplies.