Impervious surfaces associated with urban development cause increased runoff intensity during precipitation events. Green stormwater infrastructure such as rain gardens and bioswales can increase retention capacity, slow down runoff, and reduce flooding. Understanding the hydrologic impacts of onsite factors can elucidate whether or not the green infrastructure mitigates flooding. This study aimed to quantify the hydrologic effects of these rain gardens and bioswales at a community garden in Kent to understand if the gardens helped mitigate flooding issues in this area using a combination of onsite data collection and high resolution stormwater modeling. To achieve this, we compared the current condition to the previous higher impervious surface coverage condition. Probes monitoring water depth, conductivity, and temperature inside three storm system sumps were deployed on site, as well as rain gauges to cross reference with rainfall data obtained through NOAA radars. The previous condition was modeled using publicly sourced LiDAR data produced before the construction of the rain garden to create predictive simulation models of the hydrologic characteristics of the site when it was covered with a larger proportion of impervious area. This comparison elucidates the impact of this community garden on the local urban hydrology and flooding issues of the area, which can inform future management and stormwater mitigation decisions. 

Anaerobic digestion is a biological method of treating wastewater. Waste, such as food scraps, oils, and manure, is converted to acetate among other biodegradable organic matter in the absence of oxygen. Acetate is converted to biogas later in the digestion process, which may be captured as a renewable energy source. This study aims to determine how different dosages of substrate affect biomethane generation of anaerobic archaic culture. To explore this hypothesis, six serum bottles are filled with 30 milliliters of material from anaerobic. They are then injected with different acetate dosages. To determine the methane generation rates, gas from the headspace of each bottle was injected into a Gas Chromatography Flame Ionization Detector (GC-FID) instrument that detected the concentration of methane. Three measurements for each bottle were taken at one-hour intervals for five runs and are averaged in the results. The GC-FID rendered a graph between time and methane concentration from these measurements. The results of this study will help improve the understanding of anaerobic digester activity in response to different acetate concentrations, which is critical in establishing stable, large-scale digestion operations. 

Anaerobic digestion is a biological process that converts waste into biomethane, a renewable energy source. Acetate conversion is the last step of anaerobic digestion and is the most likely to fail in methane production. Understanding the microorganisms responsible for this process, and the conditions they thrive in, can help to increase success of that final step. Previous studies have concluded that changing the acetate feeding conditions of a digester will select for different microbial species. Starting with established lab-scale acetate-fed digesters, this study aimed to identify the present species through DNA extraction and sequencing. Samples were extracted over the course of a week from digesters that varied in feeding schedule. Statistical analysis of the DNA sequences was then completed to determine the diversity in archaeal and bacterial species, and the richness of those species. The variance between digesters was visualized using Principal Coordinate Analysis (PCoA). This data confirmed that digesters operated under different feeding conditions establish different microbial communities. Next steps will include comparing the community composition to acetate consumption kinetics. These results will help advance the understanding of conditions required to ensure stabilized biomethane energy production from anaerobic digestion.