Part I of this study describes the results of ozonation and biodegradation studies on three different types of water samples. The results indicate that ozonation improves the biodegradation of the organics in these samples. Part II describes activated carbon adsorption studies on one type of the water sample, the water collected from a river containing organics originating from human activities as well as natural vegetative degradation. Activated carbon adsorption isotherms were obtained before and after ozonation and after biodegradation. These showed that ozonation does not change, consistently, the adsorptivity of organics, however, biodegradation markedly improves adsorptivity. Continuous column studies indicate that granular carbon adsorption removes Total Organic Carbon according to the adsorptive equilibrium indicated by the isotherm studies and preozonation was shown to have little effect on organic removal. Activated carbon is also shown to be an excellent adsorbent for organic halogens and polycyclic aromatic hydrocarbons. A shock loading of orthochorophenol is shown to be adsorbed completely after the adsorbents appeared to reach adsorptive saturation by non–halogenated organics.