A Case Study on Emergency Response Planning using SWMM: Evaluating the Transport of Biological Agents under Different Rainfall Scenarios and Urban Surfaces
Citation:
Yuan, L., A. Mikelonis, AND E. Yan. A Case Study on Emergency Response Planning using SWMM: Evaluating the Transport of Biological Agents under Different Rainfall Scenarios and Urban Surfaces. 2023 EPA International Decontamination Research and Development Conference, Charleston, SC, December 05 - 07, 2023.
Impact/Purpose:
This study highlights the workflow of SWMM spore contamination model construction. It demonstrates the potential use of SWMM for emergency planning and remediation by evaluating spores washoff from urban surfaces under different precipitation conditions. The poster will be of interest to emergency responders and stormwater practitioners.
Description:
The U.S. Environmental Protection Agency’s Storm Water Management Model (SWMM) was used to evaluate the potential concentrations and migration pathways of spores spread by urban stormwater following a hypothetical biological agent terrorist attack or accidental pathogen release at the U.S. Coast Guard Base Elizabeth City, North Carolina, using a 6-hour natural rainfall event on Dec. 8, 2021 and two design storms (2-year and 100-year return period events). The SWMM model was built using data from a digital elevation model (DEM), land use and land cover (LULC) map, soil map, urban drainage system engineering files, and a point-scale field study that measured spore concentrations in natural stormwater runoff from different urban surfaces: asphalt, grass, and concrete. The model was calibrated using an exponential washoff function and the observed spore concentrations from the field study. The calibrated model was then used to simulate spore concentrations in runoff under different rainfall scenarios, including a natural rainfall event and two design storms. The results showed that concrete surfaces generated higher average spore concentrations (175%, p < 0.05) than asphalt surfaces, both in the simulated scenario and in the field experiment. The calibrated washoff coefficient (c1) and exponent (c2) were 0.01 and 1.00 for asphalt, 0.05 and 1.45 for grass, and 2.45 and 1.00 for concrete, respectively. This study highlights the workflow of SWMM spore contamination model construction. It demonstrates the potential use of SWMM for emergency planning and remediation by evaluating spore washoff from urban surfaces under different rainfall conditions.