Thesis
Highway stormwater media filter drains: existing doeskin longevity evaluation
Washington State University
Master of Science (MS), Washington State University
2013
Handle:
https://hdl.handle.net/2376/104799
Abstract
The Media Filter Drain (MFD) is a Best Management Practice (BMP) used to treat highway runoff. It is a trench filled with a specific media mix that filters stormwater. The long-term efficacy of MFD at removing dissolved zinc and copper from stormwater was evaluated. Media of different ages were collected from existing MFDs at two sites, both located in Western Washington. Site A was 12 years old and Site B was 5 years old. Columns made with these media mixes received highly concentrated 'accelerated aging' synthetic copper and zinc solutions for a total estimated metal loading of 19 to 27 years. Throughout the aging process, the average removal was greater than 90% for both copper and zinc at both Sites. However, even though the MFD at Site B was younger, a slight decrease was observed in the efficacy in zinc and copper removal near the end of the long-term aging with minimum removals of 71% and 65% for zinc and copper, respectively. This site did not have any grass or other layer above the media in the field and unfiltered runoff may have resulted in higher particulate metals loading. The variability in removal rates was also evaluated based on media taken from different depths from each of the two sites (top, middle, and bottom). This was v done to evaluate where the metals might be retained to aid in design or remediation options. Little or no difference was observed with regards to the three different layers. Moreover, the location of the active ingredients in the existing MFDs was unknown and no typical vertical metal removal trend could be deduced from the column experiments. All removal efficiencies were above 71%. Based on this study, the lifespan of MFD for zinc and copper treatment is significantly greater than the initial ten year estimate. Removal rates were substantially higher than that observed in the previous study on MFDs (WSDOT, 2006). Moreover, the addition of a grass layer on top of the media mix bed may enhance the MFD's removal capacities.
Metrics
7 File views/ downloads
21 Record Views
Details
- Title
- Highway stormwater media filter drains
- Creators
- Agathe Thomas
- Contributors
- Liv M. Haselbach (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525275301842
- Language
- English
- Resource Type
- Thesis