We measured organochlorine pesticides (OCPs) in sediment cores (collected in two independant ponds) to study the relationships between sediment deposits characteristics and organic contaminants, and the temporal trends of OCPs were reconstructed since 1940s in the Eure River watershed, major tributary of the Seine estuary (France).The analysis of particulate OCPs from the sediment cores (MAR16-02 and DAM17-02) was performed using microwave-assisted extraction, with toluene:acetone mixture for extraction. Following the microwave-assisted extraction, a gas chromatograph (7890B, Agilent, US) coupled to a mass spectrometer (MS; 7000C) was used to measure the concentrations.