Aligned with the advancement plan of the Ministry of Environment to regulate organic matter, research on the transformation of total organic carbon (TOC) in public sewage treatment facilities to determine the limits of allowance for organic matter in wastewater discharged from workplaces is in process. However, since TOC emission standards have a great impact on industries, it is essential to establish organic emission standards according to the type of industry. In this study, we have investigated wastewater emission scale 1 production site of synthetic resin and other plastic manufacturing facilities located in Yeosu National Industrial Complex. We have compared and evaluated the organic pollution indices of the mixed raw wastewater generated from each process wastewater, intermediate treatment, and effluent water after final treatment. The rate of oxidation of BOD and COD_Mn was 50% or less depending on the production process and the treatment process. The use of BOD and COD_Mn in such a wastewater treatment plant may underestimate the organic matter evaluation due to the low oxidizing power of the degradable organic material. This phenomenon is also observed in the J public sewage treatment plant, where the wastewater discharged from various workplaces in Yeosu National Industrial Complex is collected and processed. Therefore, it is necessary to use TOC as an organic matter index item of industrial wastewater. Additionally evaluation of the pollution loading of each production process and TOC monitoring can contribute to the efficient operation of wastewater treatment plant.