Measurement of Biochemical Oxygen Demand (BOD) has long been the basic means for determining the degree of water pollution. It is one of the most important measurements made in the operation of a sewage treatment plant. By comparing the BOD of incoming sewage and the BOD of the effluent water leaving the plant, the efficiency and effectiveness of sewage treatment can be judged. If water of a high BOD value is admitted to a river, the bacteria in the river will oxidize the organic matter, consuming oxygen from the river faster than it dissolves back in from the air. If this happens, fish will die from lack of oxygen. Thus, it is essential that a sewage treatment plant remove as much as possible of the BOD of the sewage water passing through it. To check sewage treatment effectiveness and to study and control organic-matter pollution, millions of BOD tests are performed in the United States.
Meets WA Department of Ecology Criteria for Wastewater Treatment Plant Operators and will earn Wastewater CEU.