Taiwan in facing the international trend of carbon reduction has enhanced more local enterprises to engage in carbon disclosure and carbon neutrality in order to transform into the method of green production. The purpose of this study is to demonstrate the voluntary carbon disclosure of wastewater treatment plants by conducting the first phase of carbon inventories operations for various departments
as a demonstration of ESG in according with environmental and net zero policies. Research method: the functions of Wastewater treatment plant not only treat wastewater but also serve as carbon neutralization and environmental education centers in the future. The AHP framework is used to assess the carbon reduction of wastewater treatment departments however the CCR is used as an efficiency assessment tool to replace the lack of two-by-two comparisons in the AHP. Three experts familiar with carbon reduction and inventory operations were invited to evaluate major and minor assessment criteria in the assessment hierarchy including "operation efficiency", "maintenance efficiency", "administrative system", "laboratory department" and "management department" by using questionnaires and the CCR model of the Data Envelopment Analysis (DEA) method. The results of this study shows that the θ value of "operation department" is 1, the θ value of "maintenance department" is 0.625956, the θ value of "maintenance department" is 0.5516287 and the θ value of "laboratory department" is 0.625682. As the result, units with a performance value of 1 are worthy of emulation by other units and units with performance scores below 1 are required to make improvements in the sub-assessment criterion for carbon inventory and disclosure compliance.
