Chile annually produces 2 million tons of kraft mill pulp using pine and eucalyptus as raw materials. In spite of the primary and secondary treatment processes installed in almost all of the industries, the discharged effluents still contain color, affecting light transmission in aquatic systems. At present, 75 tons of color is produced daily by industrial processes that require 57,000 m(3)/d of fresh water for processing. This chapter evaluates a tertiary treatment with Eichhornia crassipes that is used to remove color and organic compounds from kraft mill effluent. E. crassipes removed 46-75% of organic matter and 11-17% of total phenolic compounds. Under experimental conditions, E. crassipes was able to remove around 8.5% and 23.6% of color when the assays were done with 50% and 10% kraft mill effluent, respectively.