The symposium on Biological Monitoring of Water and Effluent Quality was held at the Virginia Polytechnic Institute and State University, Blacksburg, Va., 2—4 Nov. 1975. The symposium was sponsored by ASTM Committee D19 on Water. R. E. Sparks, K. L. Dickson, G. F. Westlake, and John Cairns, Jr., presided as session chairmen. John Cairns, Jr., K. L. Dickson, and G. F. Westlake, Virginia Polytechnic Institute and State University served as editors of this publication.