This book represents the proceedings of the first major international meeting dedi­ cated to discuss environmental aspects of produced water. The 1992 International Pro­ duced Water Symposium was held at the Catamaran Hotel, San Diego, California, USA, on February 4-7, 1992. The objectives of the conference were to provide a forum where scientists, regulators, industry, academia, and the enviromental community could gather to hear and discuss the latest information related to the environmental considerations of produced water discharges. It was also an objective to provide a forum for the peer review and international publication of the symposium papers so that they would have wide availability to all parties interested in produced water environmental issues. Produced water is the largest volume waste stream from oil and gas production activities. Onshore, well over 90% is reinjected to subsurface formations. Offshore, and in the coastal zone, most produced water is discharged to the ocean. Over the past several years there has been increasing concern from regulators and the environmental commu­ nity. There has been a quest for more information on the composition, treatment systems and chemicals, discharge characteristics, disposal options, and fate and effects of the produced water. As so often happens, much of this information exists in the forms of reports and internal research papers. This symposium and publication was intended to make this information available, both for open discussion at the conference, and for peer review before publication.