The purpose of this document is to establish a consisten method for building and operating the mesocosms systems. Secondly, this document serves to transfer and promulgate the technology, knowledge and experience gained from the past 11 years of research to other researchers. The objectives of this document are four fold. Firstm the design modifications of the Replicated Modular Estuarine Mesocosm (RMEM) shall be described as they relate to the original design concept by Lauth et al. Secondly, a detailed, step-by-step process for the construction of one RMEM unit and its accompanying support equipment and facilities will be provided. Thirdly, a standard operating procedure (SOP) will be presented. Human heath, environmental health and safety issues will be discussed in that section. The final section will include maintenance and troubleshooting guidelines.