Outfalls, often designed as submerged multiport diffusers are gaining increased acceptance as effective means for the disposal of treated municipal or industrial wastewater, stormwater and combined sewer overflows, cooling water, and brine effluents from desali-nation plants into coastal waters and estuaries. The main objectives of the Committee are to advance the science and technology of all aspects of coastal wastewater discharges from outfalls and their design, and to facilitate communication between the diverse groups of practitioners in the field. The Committee recognizes the considerable potential for integra-ted systems of wastewater treatment and disposal that consider the response of the receiving waters and their natural assimilative capacity. The design and siting of submarine outfalls is a complex task that relies on many disciplines including oceanography, civil and environmental engineering, marine biology, construction, economics, and public relations. These diverse disciplines are rarely brought together in a single group and the strength of the Joint Committee is the linkage of the expertise of IWA, which is more oriented towards wastewater treatment and water quality issues (e.g. bacteria modeling, nutrient transforma-tion, algae growth, sedimentation and flocculation processes), with the expertise of IAHR, which is more oriented towards hydraulics and fluid mechanics (e.g. jets and plumes, stratified flows, coastal flows, mixing and transport processes, physical and numerical mo-deling, wave forcing, pipe scouring, internal manifold hydraulics).