Chemical analyses of surface water in Illinois, 1975-77--Volume II, Illinois River basin and Mississippi River tributaries north of Illinois River basin

Samples of surface water were collected and analyzed by the Illinois Environmental Protection Agency. The results from water years 1975 to 1977 are presented in three volumes. The history of sampling and analytical methods used during that period are summarized. Stream discharge data from records of the U.S. Geological Survey are included for all sites where samples were collected at gaging stations or near enough that reliable discharge estimates could be made. Volume II includes the Illinois River basin and Mississippi River tributaries north of Illinois River basin.