A new subtidal ocean sewage outfall was commissioned in February 1989. This outfall replaced an old intertidal outfall, and presently discharges via a diffuser in an average depth of 15 m some 1.2 km off-shore in Bass Strait. Examination of biological communities around the old outfall prior to the change revealed distinct differences in biotic assemblages close to the outfall. An ongoing monitoring programme, implemented in 1986, has assessed not only the recovery in this intertidal area, but also the major changes to macroalgal communities on surrounding reefs, subtidal infauna populations in sandy sediments, and rocky shore communities.