Date of Award:
Master of Science (MS)
Civil and Environmental Engineering
Jeffery S. Horsburgh
In many urban areas, stormwater runoff can threaten the ecological health of streams and downstream water bodies. Due to the increased impervious nature of urban landscapes, runoff is more “flashy” and as a result, high concentrations of pollutants can be transported in shorter periods of time than in more natural environments. One pollutant of concern is dissolved organic matter (DOM). DOM is important within aquatic ecosystems, but excess amounts can cause depletion in dissolved oxygen concentrations and can negatively affect aquatic organisms. This study investigated changes in DOM quantity and sources within the Northwest Field Canal (NWFC), an urban water conveyance located in Logan, Utah, USA that receives runoff during storm events. DOM was monitored at upstream and downstream locations within the canal and at selected stormwater outfalls within the study reach. During storm events, DOM concentrations were rapidly elevated to values orders of magnitude greater than in baseflow measurements, and were greater at the downstream site than at the upstream site, triggered by contributions from outfalls discharging into the canal. Changes in DOM composition during storm events confirmed that DOM is more terrestrially derived, whereas it is normally more microbially derived during baseflow conditions in the canal. These results provide better understanding of the composition of DOM in the canal system and may provide crucial information for future management of stormwater runoff that can potentially lead to the improvements of water quality in downstream water bodies.
Mihalevich, Bryce A., "Resolving Spatial and Temporal Variability in Dissolved Organic Matter Characteristics within Combined Agricultural and Stormwater Conveyances" (2017). All Graduate Theses and Dissertations. 6264.