Date of Award
Thesis - Restricted
Master of Science (MS)
Civil, Construction, and Environmental Engineering
To understand winter urban hydrological activity one must look closely at the nuances associated with winter. Snowflakes are generally more efficient at removing pollutants from the atmosphere than rainfall, leading to increased wet deposition of pollutants during winter conditions. Winter precipitation does not necessitate an immediate hydrological event. Days, weeks, even months may pass before meltwater is produced. Snowpacks formed at the sides of roads act as reservoirs, collecting wet deposition associated with snowfall events and dry deposition associated with industrial activities and traffic volumes found in urban settings. Heavy chloride loads, the result of "bare pavement" policies adopted to ensure public safety, and other pollutants associated with deicing chemicals collect in the snowpack. When a melt does occur, pollutants are not released homogeneously. Fifty to 80 percent of specific chemical constituents may be released from the snowpack within the first 25 to 30 percent of the snowpack water volume. This preferential release (acid pulse, first flush, or chemical pulse) is accompanied by an entrapment process where specific pollutants remain in the snowpack, increasing in concentration, until the final five to 20 percent of the melt occurs. Compounding the fact that pervious surfaces are limited in urban settings, during the winter the soil pore water may become frozen, preventing infiltration further. Decreased meltwater-soil interaction prevents mineralization of the meltwater, allowing pollutants to enter the urban receiving water body, in more concentrated toxic forms. The bulk of snowpack, snowmelt, and runoff correlation investigations involve studies conducted at rural sites or in the laboratory. The purpose of this research is to monitor pollution during the winter at an urban site. Snowpack and snowmelt samples were collected and analyzed. The effect of increased chloride levels on the partitioning of metals and polycyclic aromatic hydrocarbons (PAHs) between the particulate and dissolved phases are investigated. And finally, the photo-degradation of cyanide complex solutions is explored. Results of the chemical analysis along with conclusions are presented. Further research needs are also identified.
Muehring, Deron L., "Pollution by Urban Snowmelt and Its Impact on Receiving Waters" (1997). Master's Theses (1922-2009) Access restricted to Marquette Campus. 4638.