Cook Inlet, Alaska, located adjacent to Anchorage, Alaska's largest population center has received the area's raw waste discharges for five decades. A program of field measurements and data analysis was carried out to examine the effects of the raw discharge on the Inlet's low temperature, silt laden, highly mixed waters. The physical characteristics studied included temperature, suspended sediments, tidal currents and tidal dispersion. Chemical characteristics included measurements of pH, dissolved oxygen, salinity and nutrients such as silica, nitrogen and phosphorus. The biological characteristics studied were bacteria, plankton and benthic organisms. The study indicated that some pollution had occurred near the outfalls but the Inlet as a whole was extremely low in all ususal pollution indicators. Becasue of the high tidal mixing and heavy sediment concentrations the inlet water presents a very hostile environment and could easily receive additional waste loads with no detrimental effects.