Stormwater Runoff Water Quality Newsletter Devoted to Urban/Rural Stormwater Runoff Water Quality Management Issues

Some urban streams experience rapid depletion of dissolved oxygen (DO) associated with major stormwater runoff events. In some situations, the DO depletion can be sufficient to rapidly cause low DO that can lead to fish kills. This issue of the Newsletter is Part I of a two-part Newsletter that examines the role of aquatic sediments in causing the rapid depletion of DO in some urban and rural streams associated with stormwater runoff events that suspend sediments into the watercolumn where they exert oxygen demand. Also, focus is given to the potential for similar, rapid DO depletion in US navigable waterways (river and harbor systems) associated with the exertion of sediment oxygen demand when sediments become suspended into the watercolumn during storms and open water disposal of dredged sediments. While sediment oxygen demand is typically said to be associated with relatively slow biotic reactions (decomposition of organics), there are situations in which abiotic (inorganic) reactions play a major role in DO depletion in a waterbody watercolumn. Examples of these situations are discussed herein