Particular elements can, even at trace levels, impact product quality, deposit formation, and regulatory compliance. Characterization of trace and ultra-trace level constituents in aqueous and/or organic matrices has often required the need to employ more than one analytical technique. In recent years, improvements in ICP-MS technologies have made it a preferred technique for multi-element trace level characterization in a variety of matrices. Coupling ICP-MS with various liquid chromatography techniques has enabled a unique capability to speciate organo-metallics at ppb levels. This paper will show how ICP-MS has been successfully used to measure ppb levels in refinery effluent streams. It will demonstrate how hyphenated ICP-MS techniques assisted in development of bioremediation options for selenium removal in wastewater treatment plants.