Cross sectional concentration data for selected organic contaminants in river waters near the confluence of the Mississippi River and the Illinois, Missouri, and Ohio Rivers, June 1989 and May-June 1990

Water samples were collected upstream and downstream from the confluence of the Ohio River and Mississippi River to study mixing of the river waters. Samples collected in June 1989 on the Mississippi River were analyzed for alachlor, atrazine, 2-chloro-2',6'-diethylacetanilide, cyanazine, desethyl-atrazine, desisopropylatrazine, 2,6-diethylaniline, 2-hydroxy-2',6'-diethylacetanilide, metolachlor, simazine, trimethyltriazinetrione, tris(2-chloroethyl) phosphate, and tris(chloroisopropyl) phosphate. Samples collected upstream and downstream from the confluence of the Ohio River and Mississippi River in May-June 1990 were analyzed for trimethyltriazinetrione, tris(2-chloroethyl) phosphate, and tris(chloroisopropyl) phosphate. Concentration data for six to fifteen locations across the rivers are presented in tabular form for two sites in 1989 and six sites in 1990.