Ciasem River is directly impacted by residential activities at the upstream part, and potentially increasing the risk for leachate inflow. Therefore, this study aimed to analyze the impact of leachate input from Bantargebang IWMS on water quality and coliform bacteria abundance in Ciasem River. Analysis was carried out descriptively by comparing monitoring data with water quality standards according to the river designation. The results showed that all water quality parameters met the quality standards for landfill leachate water. However, certain parameters did not meet the quality standards for class II surface water, namely TDS, Ammonia, Nitrite, Manganese, Iron, Copper, Zinc, and Detergent. The analysis of coliform bacteria abundance was consistent with the quality standards. Based on the correlation test results, the increase in coliform bacteria abundance was impacted by TDS and ammonia content.