With BOD, What You See Is Often Not What You Get: The Difficulty With Accurate Testing For BOD In Industrial Stormwater Runoff

By Rob Chapler, PE, StormwateRx LLC

Biochemical oxygen demand (BOD) is a measure of the amount of dissolved oxygen used by microorganisms to break down organic material in a sample of water. As they do so, these microorganisms deplete the amount of dissolved oxygen in the water, which can be deadly for aquatic species like fish that rely on dissolved oxygen to live. Because of this hazard to aquatic life, BOD is considered an adverse pollutant in natural waterways where healthy ecosystems are protected. Several states have identified BOD as a pollutant-of-concern related to runoff of stormwater from areas that are associated with industrial activities, and, as a result, have specified water quality limits or objectives for BOD in stormwater discharges from industrial facilities.