The report is indicative of the co-operative efforts of the three states bordering the tidal section of the Delaware River to study and evaluate pollution in the Delaware River estuary. The states are Delaware, New Jersey, and Pennsylvania. The report is presented in two parts. Part one describes the tests performed, co-ordinates the data and evaluates the results of the extensive studies of the dispersion of simulated pollution discharges into the Delaware River estuary. Part two contains a potential application of the findings of the model studies to the results of a number of prototype pollution surveys of the river estuary.