This study assessed the effect of an application of mycorrhizal fungi to stormwater filter media on urban bioswale soil and stormwater in an infiltration-based bioswale aged 20 years with established vegetation. The study tested the use of commercially available general purpose biotic soil blend PermaMatrix® BSP Foundation as a treatment to enhance Earthlite™ stormwater filter media amelioration of zinc, copper, and phosphorus in an ecologically engineered structure designed to collect and infiltrate urban stormwater runoff before it entered the nearby Willamette River. These results show that the application of PermaMatrix® BSP Foundation biotic soil amendment to Earthlite™ stormwater filter media contributed to the reduction of extractable zinc in bioswale soil (-24% and -26%), as compared to the control, which received a treatment of Earthlite™ stormwater filter media only, and experienced an increase in extractable zinc levels (23% and 39%). The results presented also show evidence that after establishment mycorrhizal treatment demonstrated lowered levels of phosphorus in bioswale soil (-41%) and stormwater (-100%), in contrast to the control, which had increased phosphorus levels. The treatment contributed to reductions between 67% and 100% in every metric detected in stormwater after an establishment period of 17 weeks, while the bioswale with no mycorrhizal treatment had increases between 50% and 117%. Treatment also appeared to enhance the reduction of ammonium and nitrates, while contributing to a greater increase in soil pH.

Access to safe drinking water is an important health factor in many developing countries. Studies have shown that unsafe drinking water and poor sanitation practices leads to diarrheal disease, which is one of the leading causes of death of children under five in developing countries. Provision and proper use of household water filters have been shown to effectively improve health. This thesis is focused on the refinement and validation of algorithms for data collected from pressure transducer sensors that are used in household water filters (the Vestergaard Frandsen LifeStraw Family 2.0) deployed in Rwanda by the social enterprise DelAgua Health. Statistical and signal processing techniques were used to detect the use of the LifeStraw water filters and to estimate the amount of water filtered at the time of usage. An algorithm developed by Dr. Carson Wick at Georgia Institute of Technology was the baseline for the analysis of the data. The algorithm was then refined based on data collected in the SweetLab at Portland State University, which was then applied to field data. Laboratory results indicated that the mean error of the improved algorithm is 11.5% as compared with the baseline algorithm mean error of 39%. The validation of the algorithm with field data yielded a mean error of 5%. Errors may be attributed to real-world behavior of the water filter, electronic noise, ambient temperature, and variations in the approximation made to the field data. This work also presents some consideration of the algorithm applied to soft-sided water backpacks.

Stream ecosystems have experienced significant negative impacts from land use, resource exploitation, and urban development. Statistical models allow researchers to explore the relationships between these landscape variables and stream conditions. Weighting the relevant landscape variables based on hydrologically defined distances offers a potential method of increasing the predictive capacity of statistical models. Using observations from three grouped watersheds in the Portland Metro Area (n=66), I have explored the use of three different weighting schemes against the standard method of taking an areal average. These four different model groups were applied to four stream temperature metrics: mean seven-day moving average maximum daily temperature (Mean7dTmax), number of days exceeding 17.8 °C (Tmax7d>17.8), mean daily range in stream temperature (Range_DTR), and the coefficient of variation in maximum daily temperature (CV_Tmax). These metrics were quantified for the 2011 dry season. The strength of these model groups were also examined at a monthly basis for each of the four months within the dry season. The results demonstrate mixed effectiveness of the weighting schemes, dependent on both the stream temperature metric being predicted as well as the time scale under investigation. Models for Mean7dTmax showed no benefit from the inclusion of distance weighted metrics, while models for Range_DTR consistently improved using distance weighted explanatory variables. Trends in the models for 7dTmax>17.8 and CV_Tmax varied based on temporal scale. Additionally, all model groups demonstrated greater explanatory power in early summer months than in late summer months.

Reducing the rates of greenhouse gas (GHG) emissions is critical in combatting global climate change. Carbon dioxide (CO2) and methane (CH4) are the two most important carbon-based GHGs, for their atmospheric warming potential. Wetlands such as the Florida Everglades play major roles in the global carbon cycle, as varying hydrologic conditions lead to differential production rates of these two GHGs. This study measured CO2 and CH4 emissions in a re-created Everglades ridge-and-slough wetland, where water levels were controlled to reflect natural flood patterns. As expected, lower elevations were flooded longer and produced more CH4, while higher elevations produced more CO2. Since CH4 has a relatively high global warming potential, CO2 production would need to be 70 times that of CH4, to balance their GHG output. The average ratio of CO2 to CH4 across elevations was 22.0 (mol:mol), indicating that future water management within wetlands should consider GHG production potential.

Densification and submergence of floating crude oil is proposed as a novel oil spills treatment method. Surface application of dry granular materials (e.g., quartz sand, limestone) on top of a floating oil layer increases the density of the floating oil phase/granule mixture and leads to formation of relatively large and stable aggregates with significant amounts of captured oil. The aggregates separate from the floating hydrophobic phase and settle by gravity. Implementation of this method will reduce the impact radius of a spill and its mobility, preventing direct contamination of beaches, coastal flora and fauna. The major objective of this research was to examine interactions of particles with hydrophobic liquid-water interface from different perspectives. The important characteristics of the process, such as oil removal efficiencies, optimal particle-to-oil ratios and particle size ranges, were experimentally defined. A series of experiments was conducted to investigate aggregation and dissolution rate constants of the submerged hydrophobic liquids in salt water and deionized water, and to study the impact of the surface porosity of the granular particles on oil capture efficiencies. In addition to crude oil (South Louisiana crude, MC 252), aggregation volumes of quartz sand with other hydrophobic liquids (alkanes and aromatics) were analyzed in relation to wetting characteristics and physical properties of the liquids. A classification of the main types of oil-particle aggregates was developed based on the formation characteristics of the aggregates. Moreover, under specific conditions, depending on the application rates of the granular materials, unique interactions of the particles with the hydrophobic liquid-water interface were observed and defined (bowl formation and roping). These concepts can be utilized to control surface mobility of floating oils, especially during the initial stages of an oil spill, while the oil layer is intact, and when other treatment methods may not be suitable near coastal areas, where transport of floating oils can significantly impact coastal ecosystems.

Kosovo is a disputed territory, in conflict with Serbia, the country it declared independence from in 1999. The two states share water resource, in the form of the Ibër river. Kosovo is facing issues of water scarcity and the water it has access to is heavily polluted with untreated wastewater metallurgy waste.Kosovo does not only have poor relations with Serbia, there are also conflict within Kosovo with communities of both Kosovo Albanian majority and Serb majority. These communities have shown different willingness to cooperate over the water management of the Ibër river basin. Cooperating over shared water resources have in other cases been used as a way to improve on relations in conflict affected societies, through environmental peacemaking. In this case study, the environmental and socio-political conditions for environmental peacemaking is investigated through interviews of municipal and regional stakeholders, involved in the management of the Ibër river basin. Interviews were conducted with two municipal employees and one representative from the regional river basin authority in Kosovo. These interviews were complemented with a comprehensive literature review. The findings were analysed, using a conceptual framework developed to analyse and compare different cases of environmental peacemaking. The conceptual framework consists of six elements: resource scarcity, interdependence, lack of environmental sustainability, mutual interests, shared values, and power (a)symmetries. External actions and interests was also included as an element to reveal in what way external actors can intervene and assist in improving relations through environmental peacemaking initiatives. The analysis concluded that the Ibër river basin is in a need of transboundary management to improve on the water quality in a more effective and efficient way. The resource scarcity that is currently facing the stakeholders could be used as a cooperative trigger between the different actors. And while there is a lot of complexity to within the socio-political conditions, the interviewees express the need and interest for increased cooperation. This indicates that increased collaboration could be possible, but most likely there would be a need for external interventions to create an ongoing dialogue, that in turn can build trust between the conflicting parties. / <p>Remote presentation on Teams</p>

Narragansett Bay, Rhode Island, is a valuable natural resource that suffers summer hypoxic events resulting from over a century of cultural eutrophication. Current efforts to reduce nitrogen loading from wastewater treatment facilities discharging into the Bay and its tributaries hold the promise of working towards ecological restoration. But, the efficacy of these efforts may be limited, or undone, if future changes in climate or land use increase nutrient and sediment loads to the Bay. This study developed a SWAT model of the upper Narragansett Bay watershed to simulate water quantity and quality. The baseline model was calibrated and validated to accurately reflect watershed behavior. I then used the model to simulate water quantity and quality under an altered climate, with an IPCC projected increase in temperature of 3°C and a 10% increase in precipitation by 2080. A second scenario incorporated projected 2080 land use in the absence of climate change. The third scenario combined the climate change and land use change alterations to examine cumulative impacts. A comparison of scenario outputs against the baseline simulation highlighted the expected impacts climate change and land use change will have on the watershed. Both climate change and land use change demonstrated impacts on surface runoff, water yield, PET and ET, streamflow, and loading of sediment, organic N, organic P and nitrate. Climate impacts were much greater than land use impacts, but land use impacts displayed greater regional variation. The results of the combined simulation indicate that future climate and land use change will likely negatively impact the Bay and undermine current efforts at restoration. However, the results also highlight the potential to utilize land use to mitigate some of the impacts of climate change.

Vernal pools are small, ephemeral wetlands lacking an inlet or outlet. These wetlands, also known as seasonal pools, are found in a wide range of biomes, and their characteristics vary based on location. While the vegetation of western U.S. pools, and amphibians of eastern U.S. pools have been extensively studied, many aspects of vernal pools have not been fully characterized. In particular, although the general seasonal wetting and drying cycle is understood qualitatively, few studies have attempted to quantify the hydrological regime of vernal pools in New England. As water level variation drives many, if not all, of the characteristics unique to these systems, more research on this aspect of vernal pool functioning is needed. The primary objective of this study was to gain a better understanding of vernal pool hydrology through the study of a complex of three pools in South Deerfield, MA. The water level in the South Deerfield pools has been monitored since 2009. For this study, the most recently recorded water year (1 October 2017 to 30 September 2018) was used to characterize the water level fluctuations in the Middle Pool. Water level was monitored manually (weekly intervals) and with pressure transducers (4-hour intervals) in permanently installed wells. The effects of precipitation and evapotranspiration on water level were quantified with a water balance analysis. This analysis also estimated changes in storage by estimated inflow from the uplands and outflow via deep seepage. Water level changes in the Middle Pool were consistent with qualitative descriptions and trends described in earlier studies in the region. We found that the countervailing effects of precipitation and evapotranspiration were the primary drivers of water level fluctuations throughout the year. However, the estimate of storage derived as a water balance residual was not representative of water level in the vernal pools. The storage estimate derived for the Middle Pool was more successful at estimating the water level during spring transition, the high water period most important to amphibian breeding.

Groundwater accounts for approximately 99% of the available freshwater on Earth, and is an important resource for irrigation, potable water, and domestic use in the United States. However, the overuse of groundwater has led to aquifer depletion in several basins across the USA, resulting in storage reduction, contamination, salt water intrusion, and depletion of surface waters. To properly manage groundwater for the future, there is a need for well-informed Groundwater Management Plans (GWMPs) in order to prevent further depletion and erosion of the resource. Previous studies have focused on groundwater management relative to groundwater laws, regulations, and institutional arrangements. This study analyzed GWMPs to better understand how allowable yields are set, how interconnected groundwater conditions are addressed, and how groundwater systems are managed when information on the system is lacking through planning. The findings of this study delineate how groundwater management goals are set across the United States and provides recommendations to inform future GWMPs.

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