Comparative discharges of fresh and waste water along the California coast

Abstract

As the population of California grows, the discharge of domestic and industrial waste water and power-plant cooling water into coastal waters continuously increases. About 0.75 × 106 m3 of industrial waste water, 3.75 × 106 m3 of domestic waste water, and 26.5 × 106 m3 of thermal effluent are discharged daily into California's nearshore waters. These waters do not have an infinite capacity to break down and disperse the pollutants. Waste water discharged near shore may remain there for considerable time and have a significant effect on water quality and marine life. The low population and wet climate of the northern coastal region have led to small discharges of waste water but very large inputs of fresh water to the ocean. Southward along the Pacific Coast the climate becomes more arid, and population increases. This combination leads to a large excess of waste-water over fresh-water discharge. Many individual waste-water discharges exceed the average daily discharge of most of the rivers which enter the coastal waters.