Chemistry and microbiology of a sewage spill in South San Francisco Bay

During three weeks of September 1979, the breakdown of a waste treatment plant resulted in the discharge of a large volume (1.5×10⁷m³) of primary-treated sewage into a tributary of South San Francisco Bay, California. Chemical and microbial changes occurred within the tributary as decomposition and nitrification depleted dissolved oxygen. Associated with anoxia were relatively high concentrations of particulate organic carbon, dissolved CO₂, CH₄, C₂H₄, NH ₄ ⁺ , and fecal bacteria, and low phytoplankton biomass and photosynthetic oxygen production. South San Francisco Bay experienced only small changes in water quality, presumably because of its large volume and the assimilation of wastes that occurred within the tributary. Water quality improved rapidly in the tributary once normal tertiary treatment resumed.