Biogeochemical Cycling of Nutrient Elements in Stormwater Retention Ponds

Student: Tyler Roberts

Major: Geology

Mentor: Dr. Vijay Vulava

Department: Geology

Biogeochemical Cycling of Nutrient Elements in Stormwater Retention Ponds 

Coastal development has led to increased impervious ground cover, impeding the natural infiltration of rainwater, resulting in more flooding events. Stormwater retention ponds (SWPs) have become the best management practice (BMP) holding runoff to reduce flooding and slow discharge into natural water bodies. SWPs accumulate contaminants as stormwater runoff flows through the urban watershed. Contaminants found in the SWPs are dependent on the land usage of the surrounding watershed with potential sources of contamination including fertilizers from residential or agricultural areas as well as petroleum by-products from regions with high volumes of automobile traffic. The contamination in water is present in physical (sediment, nanoparticles, other particulate matter, etc.), chemical (nutrients, trace metals, complex organic chemicals, etc.), and biological (pathogens) forms. Their fate in the environment is governed by complex physical and biogeochemical processes (contaminant chemistry, sorption, degradation, transformation processes, and transport). This project was designed to test our conceptual model that outlines all hydrological, physical, and biogeochemical processes that occur in SWPs. The focus was to create an environmental systems analysis of nitrogen (N) and phosphorus (P), two major nutrient elements that cause algal blooms in SWP systems in the low country of South Carolina. The specific objectives included (i) quantifying total concentrations of N and P in the water column, bed sediment, groundwater, algal mats, and floating vegetation and (ii) measuring inflows and outflows of N and P in the SWP by sampling water in surface runoff and groundwater flows. A freshwater SWP located at the Stono Preserve was used as the primary site for sample collection with sample processing and analysis occurring at Dr. Vulava's research lab in SSMB.