TigerStream 2: Sediment Basin Research, Megan Armstrong

Abstract: Highway construction projects disturb existing vegetation, leaving soil vulnerable to erosion from environmental factors such as rainfall and wind. Rainfall induced soil erosion is transported via stormwater runoff and is deposited into receiving waterways. To minimize downstream impacts, sediment basins are employed on construction sites to capture, detain, and remove sediment from stormwater runoff. While standardized sediment basin design guidance exists, further research is necessary to optimize designs and ensure that guidance is backed by engineering principles. To better understand the performance of sediment basins, intermediate-scale experiments were conducted to examine performance impacts based on a sediment basin’s volumetric and geometric properties. Additionally, various treatment methods were evaluated to assess their effects on sediment capture, including baffles, silt-fence serpentine baffles, a level spreader, and chemical flocculants. Three trapezoidal basins—Basin A (2L:1W) with a volume of 0.4 m3 (15.3 ft³), Basin B (10L:1W) with a volume of 0.4 m3 (13.5 ft³), and Basin C (2L:1W) with a volume of 0.2 m3 (7.0 ft³)—were designed and evaluated in a controlled environment. Basins A and B, reflecting typical volumetric sediment basin designs with coir baffle treatment and a skimmer, captured 88% of introduced sediment. The inclusion of coir baffles enhances sediment capture by up to 10%. Basin C achieved 91% sediment retention using a single coir baffle and chemical flocculants. This study indicated using a reduced basin volume along with chemical flocculants may provide equivalent or greater sediment capture compared to typical basin designs with larger volumes, providing substantial cost savings.

Bio: Megan is a Ph.D. student in Auburn University's Department of Civil and Environmental Engineering under the advisement of Dr. Michael A. Perez. She also works as an engineering intern for Fagan Consulting, LLC under the advisement of Barry Fagan. Further, she currently serves as the technical connection between Auburn University and Fagan Consulting as they work on an SBIR project that entails developing a small-scale, portable electrical flocculation device to help meet stormwater quality goals. She obtained her master's degree from Auburn University in the summer of 2023 in civil engineering after defending her thesis project titled: "Optimization of Sediment Basin Configurations." She graduated Magna Cum Laude from Mississippi State University in the summer of 2021 with a bachelor’s degree in biological engineering with an environmental emphasis.