Surface waters are generally colored by natural organic materials such as humic, fulvic and tannic acids. These compounds result from the decay of vegetative materials and are generally related to condensation products of phenol-like compounds; they have conjugated carbon/carbon double bonds. When the series of double bonds extend upwards of twenty, the color absorption shows up in the visible spectrum. Ozone is attracted to breaking organic double bonds. As more of these double bonds are eliminated, the color disappears. Surface water can usualy be decolorized when treated with 2 to 4 ppm of Ozone.