The oxidation of harmful organic compounds contained in aqueous waste effluents known as super critical water oxidation, SCWO, has been worked out since the 1980s. This highly efficient end of the pipe process operates at pressures and temperatures above 221 bar and 374 degrees C, the critical point of water. R&D experience and the technological state including economical and regulatory aspects are reviewed and further R&D needs are discussed in this article. Future applications are also seen in coupling supercritical CO2 extraction with oxidation to treat contaminated materials and in Supercritical water gasification, SCWG, to convert biomass and organic wastes to hydrogen.