The physical, chemical and biological attributes are described for: (1) a coastal marine environment centered about a Department of Energy Strategic Petroleum Reserve (SPR) brine disposal site located 11.4 km off the southwest coast of Louisiana; and (2) the lower Calcasieu and Sabine estuarine systems that provide leach waters for the SPR project. During the study period, the daily discharge averaged 529,000 barrels of 216 0/00 brine, representing a loading of 18,000 metric tons of salt per day. The objective of this study are: (1) characterize the environment in terms of physical, chemical and biological attributes; (2) determine if significant adverse changes in ecosystem productivity and stability of the biological community are occurring as a result of brine discharge; and (3) determine the magnitude of any change observed. This report describes the methodology and significant results of the first year's monitoring effort of the West Hackberry brine disposal site. The investigative tasks, presented as separate sections, are: Physical Oceanography, Estuarine Hydrology and Hydrography, Analysis of Discharge Plume, Water and Sediment Quality, Special Pollutant Surveys, Benthos, Nekton, Phytoplankton, Zooplankton and Data Management.