Announced 13 days in advance due to delays in Student Services processing.
School of Civil and Environmental Engineering
Ph.D. Thesis Defense Announcement
GREEN INFRASTRUCTURE DESIGN: PERFORMANCE OF VEGETATED FILTER STRIPS OPTIMIZED FOR INFILTRATION AND SORPTIVE AMENDMENTS
By A. LYNNAE STYPULKOWSKI
Advisor:
Dr. SUSAN BURNS
Committee Members: Dr. J. DAVID FROST (CEE), Dr. SHENG DAI (CEE), Dr. JENNIFER GLASS (EAS), Dr. TERRY STURM (CEE)
Date and Time: APRIL 17, 2024. 10 AM EST
Location: (Hybrid) SEB 122 and Zoom https://gatech.zoom.us/j/96247109251
Complete announcement, with abstract, is attached.
ABSTRACT
Urbanization causes degradation in the natural ability of a watershed to mitigate
stormwater runoff, which results in increased water volume and pollutant loads
discharging to natural waterways. To minimize that impact, the design of green
infrastructure for stormwater control mimics the pre-construction hydrology of a
developed area using best management practices (BMPs) designed with three
primary goals: minimizing runoff flowrate to reduce flooding and erosion; maximizing
pollutant deposition to reduce discharge to natural waterways including
groundwater; and increasing groundwater recharge and with an added filtration
component.
Because stormwater BMP permitting can result in differences in prioritized design
parameters, inconsistent efficiency measurements, and an extremely wide range of
quantification methods, this work focused on bringing uniformity to the design and
performance of the vegetated slope that is designed for stormwater control. In this
study, an analytical model was developed to incorporate both overland flow and soil
infiltration in the BMP’s partially saturated soils to optimize designs for lower
stormwater discharge volumes and longer residence time. Additionally, field and
laboratory studies were performed to study the transport and deposition of solid
phase contaminants (soil and rubber) to quantify solids deposition profiles
throughout the length of a vegetated slope. Dissolved heavy metal transport through
the vegetated slope was evaluated based on the adsorption characteristics of the
deposited sediment profile of the BMP. Results showed that the flow rate could be
reduced by up to 19% in silty sandy soils in unsaturated conditions when accounting
for infiltration. Further, 99% of solids were deposited in the first 2 meters of a
vegetated slope, which agreed well with modeled trapping efficiencies based on
particle diameter and density. Adsorption analysis showed that Piedmont soils
sorbed relatively small concentrations of heavy metals; however, incorporating even
small percentages (by mass) of a highly sorbent component (activated carbon) in
the soil regime increased both infiltration and adsorptive capacity, substantially
increasing the filter strip’s performance.