The authors found that the system was not as effective at removing TP (26% reduction) and SRP (19% reduction) masses. The next two studies featured in the SI characterized the efficacy of control measures to treat pollutants from stormwater [9] or industrial wastewater [10]. Research by [PERSON] and [PERSON] [9] quantified the removal efficiency of total dissolved nitrogen (TDN) in urban runoff after converting a dry detention basin into a stormwater wetland. The TDN treatment efficiency increased from 0% to 63% after the wetland conversion. Data from high-frequency physicochemical loggers showed that the hydrologic retention time increased, dissolved oxygen, and the oxidation reduction potential decreased, creating an environment that was more conducive to nitrogen removal via denitrification. The next study, authored by [PERSON] et al. [10], studied the efficacy of a constructed wetland to treat pyroligneous liquor waste from a gasification plant. In this study, the authors inoculated the constructed wetland with arbuscular mycorrhizae fungi (AMF) and plant-growth-promoting bacteria (PGPB) to enhance interactions between plants and microflora in the rhizosphere to maximize phytoremediation. Results from the field experiment suggest that using AMF and PGPB in a constructed wetland can enhance the phytoremediation of water-quality contaminants. However, the authors found that ammonium-nitrogen concentrations increased between inflow and outflow, suggesting their wetland may act as a source of nitrogen. Both these studies highlight the versatility of wetland applications in bioremediation of pollutants from human land uses. The final two studies in the SI characterized the treatment of fecal indicator bacteria by onsite wastewater treatment systems (OWTSs) [11; 12]. [PERSON] et al. [11] developed a unique method for estimating the required thickness of saprolite (weathered rock subsoil common in Piedmont and Mountain regions) to completely remove _Escherichia coli_ from septic tank effluent in soil textures ranging from clay loam to sand. Results from their study indicated that a mean thickness of 58 cm (range: 35 to 113 cm) was required to completely filter _E. coli_ from wastewater. The authors found that the silt percentage was the best indicator to estimate the necessary thickness for safe wastewater disposal. If OWTSs are designed with inadequate separation distances, _E. coli_ in wastewater effluent may not be completely filtered and the incompletely treated effluent can pollute groundwater underlying the OWTS. If _E. coli_ is not removed within the groundwater system, it may discharge into surface water downgradient from active OWTSs. The final study, authored by [PERSON] et al. [12], compared the concentrations and exports of _E. coli_ and _Enterococcus_ spp. (henceforth referred to collectively as fecal indicator bacteria (FIB)) from watersheds served by various wastewater treatment technologies. The authors found that the watersheds with the highest density of OWTSs (approximately 0.4 systems ha\({}^{-1}\)) contained greater FIB concentrations and exports relative to the watersheds with the lowest densities; however, only differences in FIB concentrations were statistically significant. The results from this study suggest that OWTSs can affect water quality at the watershed scale, especially when watersheds contain elevated densities of OWTSs. Both the studies included in this SI emphasize the role that OWTS can play in the delivery of FIB to water resources. Inadequate filtration at the site scale can result in watershed-scale impacts, especially if there are numerous OWTSs with incomplete FIB filtration located in the same watershed. The articles included in this SI advance the study of water treatment and management of pollutants that enter water resources from agricultural, stormwater, or wastewater sources. Despite these advancements, there remains much work to improve water treatment and management.