Many industrial operations produce phenolic wastes which are objectionable to receiving waters by conventional biological treatment, It has been established that some actinomycetes, especially Streptomyces species, are capable of decomposing a wide variety of aromatic compounds, including phenols, The.purpose of this investigation was to determine the growth characteristics of an aquatic actinomycete and to evaluate its potential for degrading o-chlorophenol. Results of the investigation showed that this Streptomyces species has two growth stages, primary and secondary. In the primary stage, growth was restricted to the bottom or subsurface of both liquid and solid media, Secondary growth occurred extensively on the medium surface, Orthochlorophenol degradation was evaluated by adding it in different concentrations to the developing cultures of the organism. The rate of degradation was increased by increasing the dose of o-chlorophenol up to a concentration of 400 milligrams per liter, Growth inhibition was clearly evident at a concentration of 500 milligrams per liter. / Master of Science