Influence of long-term sewage irrigation on the distribution of organochlorine pesticides in soil-groundwater systems

► HCH, DDT and Endosulfan compounds are main OCPs in the study area. ► Over-exploitation of groundwater has changed the flow field of groundwater. ► Positive correlations occurred between OCPs content in soil and in groundwater. ► Sewage irrigation influenced the distribution of OCPs in soil-groundwater systems. ► Groundwater flow and current pesticide use were two major influence factors.