Triazine, organophosphate and pyrethroid (TOP) pesticide data from river water collected at various sites within the Humber catchment area as part of the Land Ocean Interaction Study project (LOIS).. Water samples were collected weekly and during storm periods between 1994 and 1996. The unfiltered samples were extracted on the day of collection using solid-phase-extraction (SPE), the SPE cartridges stored overnight at 4 degreesC and then transported to the Institute of Freshwater Ecology (IFE), Wareham for elution, drying and Gas Chromatography (GC) analysis. Pesticides measured were Atrazine, Cyanazin, Desmetryn, Fenitrothion, HCH gamma, Malathion, Parathion, Permethrin, Prometryn, Simazine, Terbutryn. The sampling and extraction of the pesticides was carried out by the LOIS team at York University and the elution and sample preparation for GC analysis was done at IFE.