development of improved wastewater treatment facilities to reduce color and cod in dye-containing effluents is a problem of serious concern for both the textile and carpet industries. existing biological treatment facilities reduce bod to acceptable levels but are generally unsuccessful in reducing cod and color. although previous studies have indicated that microbial populations would not significantly reduce the color of commercial dyes in dyehouse effluents, all of these studies sampled only the treatment facilities of the mills as a source of organisms which might have decolorizing potential. a wide variety of environmental sources were sampled for populations which could grow in dyebath solutions and decolorize the dyestuffs. carpet mill samples consisting of disperse dyes, acid dyes and disperse-acid mixtures were recalcitrant to microbial degradation. textile dyes, however, could be decolorized by microbial populations. of the textile dye samples analyzed, 70 showed significant reduction. these suggest that microbial populations might be successfully incorporated into the design of treatment facilities for dye-containing effluents