Analysis of diverse methods of water quality evaluation according to practical application

The South Korean government has developed various policies and systems with the aim of improving water quality and restoring the health of aquatic ecosystems. Evaluation of whether a target water quality has been achieved may produce different results depending on the systems and policies used, which can undermine the reliability of the results. This study aimed to identify a scientific and systematic water quality evaluation method to enable the government to implement rational policies and systems. We used data from the “Youngbon A” location to evaluate target water quality according to the total maximum daily load of pollutants in the Youngsan River watershed, and applied existing and new evaluation methods to verify the validity of each method and identify the optimal choice. We found that different evaluation methods produced different results in terms of meeting the target water quality. For the point of “Youngbon A”, manifesting great fluctuation in the level of water quality due to increasing inflow of pollutants, the level of water quality evaluation, calculated by removing part of the upper outlying values of water quality attributable to increased inflow of pollutants, was derived as reasonable measurement.