United States Department of Transportation
i
Vegetated Biofilter for Post Construction Storm Water Management for Linear Transportation Projects – Dormant Grass Test Supplement
-
2010-12-01
[PDF-7.68 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
TRIS Online Accession Number:1329776
-
Edition:Technical Report Supplement
-
Corporate Publisher:
-
Abstract:The vegetated biofilter is a low impact development technique that can be integrated into stormwater management of linear transportation systems and capitalize on the natural environment to mitigate stormwater. In the project report (USFHWA/OH-2010/7), the behavior of a 4 ft (1.2 m) wide by 14 ft (4.3 m) long prototype vegetated biofilter slope under simulated storm events at various pollutant concentrations, slopes, and flow rates was evaluated. This supplement discusses the behavior of the same prototype during dormant or winter conditions at slopes and flow rates as follows: 8:1, medium; 4:1, medium; and 2:1, medium. Tests were conducted using methods similar to that of the original study. The influent pollutant concentration during the simulated storm events was at the “medium” level, which included medium concentration during the first part and low concentration in the trailing portion of the event. The pollutants included the same seven metals, soil, and oil used in the original study. In addition chlorides were added in the influent to simulate and measure the effects of salt used for pavement winter maintenance on the biofilter. The prototype vegetated biofilter foreslope under dormant conditions provided fair to excellent performance in removal of pollutants (seven metals, suspended material, and oil and grease) from a medium concentration simulated storm water runoff. Over 80 percent removal was achieved for all constituents except iron (75%), zinc (58%) and chlorides (negligible). TSS removal declined from a summer condition average removal of about 95% to 80% for the dormant condition. Results at slopes of 8:1, 4:1, and 2:1 did not indicate declining performance with increasing slope. Vegetation coverage was about 60 % for the dormant tests contrasted to an average 83% during the summer tests, which contributed to the reduction in removals. Within the parameters of this study, findings indicated that the foreslope portion of the vegetated biofilter even during a dormant condition significantly reduces the quantity of pollutants in the runoff.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
