Abstract
To evaluate characteristics of water quality in Jeju, a study was implemented for Han stream and retention ponds. Inflow water quality of retention ponds was heavily dependent on precedent rainfall, and no pesticide was detected due to the little artificial pollution sources. A smooth settling efficiency curve was noticed because heavy particles were already settled down in front of the retention pond. There were weak relationships between retention time and water quality, and this can be attributable to high concentration of pollutants influx at peak inflow. In addition, as Han stream retention pond has a role of groundwater recharge, inflow control based on water quality as well as quantity is needed to maximize pollutant removal at the retention ponds.
