No description available.

Isotopic analyses of d18O and d2H of water through the hydrologic cycle have allowed hydrologists to make better interpretations related to climate and relationships between precipitation, surface water, and groundwater. In this study 394 precipitation samples 1917 surface water samples and 1405 groundwater samples across Massachusetts was used to create an isoscape for each respective water. All samples have been collected by volunteers throughout Massachusetts. A state meteoric water line: d2H = 7.7*d18O + 9.8, surface water line: d2H = 5.7*d18O – 4.2, and groundwater line: d2H = 6.5*d18O + 2.9 was created for the state of Massachusetts. The d18O isoscape for each of the above-mentioned waters shows an isotopic separation along an east-west topographic gradient where isotopes were enriched in the eastern portion of Massachusetts and depleted in the western portion of Massachusetts. Precipitation, surface water, and groundwater show unique isotopic variability. The isotopic variability of precipitation is primarily due to seasonality, moisture source and differences in topography across Massachusetts. The d18O and d2H isotopic variability of surface water is due to a biasing of precipitation as well an enrichment due to an open water system as the surface water dataset correlates with surface water type and precipitation isotopic values. The d18O and d2H isotopic variability of groundwater is due to the dampening of surface water and precipitation because of hydrogeologic processes and the biasing of surface waters that have gone through open water isotopic variability.

In January 2010, a magnitude 7.0 earthquake devastated Haiti, one of the poorest countries in the Western Hemisphere. Haiti’s weak sanitation infrastructure and limitations in the public health system made the country susceptible to the spread of waterborne diseases. Following the earthquake, cholera rapidly spread through Haiti, killing 4,672 people in 5 months and leaving thousands hospitalized (MSNBC, 2010). Cholera is an infectious diarrheal disease caused by the pathogen, Vibrio cholerae, which results in severe dehydration with a high mortality risk. The source of the epidemic was traced to the Artibonite River, the island’s longest and most essential drinking water source (Encyclopaedia Britannica. n.d.). The origin of the contamination was later discovered to be unsanitary conditions left from United Nations peacekeepers from Nepal. Eight years later, cholera cases are still prevalent, although numbers have declined recently due to aid from private organizations (Dowell, S.F. et al 2011, Katz, J.M. 2013). However, with climate-related increases in ocean water temperatures, scientists expect hurricanes to intensify and increase damage to developing countries (Center for Climate and Energy Solutions. n.d.). Natural disasters promote the spread of waterborne illness by isolating people from safe drinking water and destroying public health infrastructure such as happened with the cholera outbreak in Haiti (Funari, E. et al 2013). To prevent future waterborne disease epidemics in such areas with limited resources, it would be beneficial to improve environmental surveillance through development of rapid, reliable, and portable detection methods for waterborne pathogens. The advent of high-throughput sequencing technologies has enabled the detection and characterization of microbial communities in their natural environments, an approach known as metagenomics. Metagenomic sequencing, unlike more traditional PCR methodologies, is capable of sequencing thousands of organisms in a sample. This metagenomic shotgun sequencing approach detects the abundance of microbes and bacterial diversity in the environment (Illumina, n.d.). The Oxford Nanopore MinION is a shotgun sequencing device that is optimal for portable, rapid detection of the microbial diversity in an environmental sample (Oxford MinION, n.d.). This handheld device has enormous potential for field use in emergency preparedness and disease response, particularly in developing countries where more advanced analytical equipment may be inaccessible due to lack of facilities or damaged infrastructure. Having access to quick, infield assessment technology for rapidly emerging outbreaks would be beneficial to a disease-specific public health response. Current protocols recommend that DNA is extracted from environmental samples as rapidly as possible after collection. If cooling is available with an insulated ice chest, samples may be transported/stored for periods ranging from 6 to 24 hours. The shorter timeframes minimize unwanted shifts in microbial structure (U.S. Geological Survey, 1997, WHO, n.d.). Access to cold storage in remote areas is unlikely, and the use of liquid preservation methods could assist in maintaining quality of DNA, and hence produce more accurate data in metagenomic analyses. In the absence of cold storage facilities, infield filtration coupled with preservation techniques are necessary to maintain samples integrity for transport to laboratory facilities. This thesis aimed to develop an infield filtration and sequencing protocol, coupled with the Oxford Nanopore MinION sequencing platform, to identify the potential bacteria, viruses, protozoa, fungi, antimicrobial resistance (AMR), pathogenic strains, and virulence associated genes for use in remote locations. Five locations across Lake Warner, Massachusetts were used for method development, coupled with Millipore Sterivex filters for field filtration to determine the most effective method for sample preparation in remote locations. Additionally, a chemical preservation method was assessed using dimethyl sulfoxide, disodium EDTA, and saturated NaCl (DESS). A study by Gray et al, found that liquid preservation methods (DNAgard, RNAlater, and DESS) outperformed the card-based preservatives (FTA cards and FTA Elute cards) in terms of bacterial recovery (Gray, M.A., et al 2013). DESS was selected for investigation in this thesis because of the low cost compared to the other liquid-based preservatives. Lake Warner in Hadley, Massachusetts, which is heavily used for fishing and boating activities, flows into the Connecticut River via the Mill River. Historically, the lake experienced high Escherichia coli (E. coli) levels due to pollution from primary effluent released in the 1950s from the Amherst Wastewater Treatment Plant (Johnson, J., 2015). Similar to Vibrio cholerae, E.coli spp is a waterborne bacteria caused by fecal contamination. Although most E.coli are natural inhabitants of the gastrointestinal tract, pathogenic serotypes can result in severe complications in vulnerable populations such as kidney failure in children and the elderly adults. (Todar, K., 2012). Lake Warner was chosen for the method development because of its history of E. coli pollution and recreational traffic as well as its general accessibility for study. Designing a methodology for rapid detection of pathogenic bacteria using a metagenomic approach could help improve surveillance for environmental pathogens that pose future epidemic risk. These tools are becoming increasingly important for prediction and response to waterborne diseases as climate impacts increase the frequency, intensity, and duration of extreme weather events that damage critical infrastructure for vulnerable populations (van Aalst, M.K. 2006).

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This thesis is a part of a project run by The Department of Geography, Faculty of Science in Charles University in Prague. This project deals with processes in floodplains of the Lužnice, the Stropnice and the Blanice rivers. The research in the floodplain of the Lužnice started in the year 2008 and is focused on the interaction between groundwater and surface water. The monitored territory it is situated to the south of a locality called Halámky and its area is 0,6 km2. In this thesis mainly the outputs of the research were elaborated. The highlighted points were the interpretation of the groundwater level behaviour, the groundwater streaming orientation in the area and interaction between groundwater and surface water. The outputs of this thesis can be used in the next stages of the project.

A series of five east-west and two north-south hydrostratigraphic cross sections were drawn from drillers' logs of water wells within the southern half of Cache Valley, Utah. These cross-sections demonstrate that ground water flow to streams is restricted by a continuous low- II permeability layer, nearly 100-feet thick. This layer was correlated to the lake-bottom deposits of the Bonneville (30,000 -13,000 years ago) and Little Valley (140,000 - 90,000 years ago) cycles of the ancient Lake Bonneville. The most productive aquifers in the valley, collectively termed the principal aquifer , are in the southeast corner , approximately between Smithfield and Hyrum, and between the eastern valley margin and the valley center. Sands and gravels of the principal aquifer were deposited as alluvial fans and deltas by streams draining the Bear River Range. Ground water chemistry in the principal aquifer system is of the calcium-magnesium bicarbonate type with total dissolved solids (TDS) averaging about 300 ± 100 mg/L. TDS and the relative proportions of sodium, potassium, and chloride increase down flowpath, from recharge areas in the east to discharge areas in the west. Oxygen-18 (18O) and deuterium (D) analyses were performed on precipitation samples at three locations on the east valley benches, four surface water samples from streams entering the valley, and fourteen ground water samples from either wells or springs. Precipitation and surface water values generally plotted along the Global Meteoric Water Line (GMWL), although the precipitation values plotted significantly lower on the GMWL than the surface water values. Of the ground water samples, twelve from the principal aquifer generally clustered near the surface water data points, suggesting that water from streams, rather than infiltrating precipitation, recharges the principal aquifer. Twelve ground water samples were analyzed for tritium. The tritium values of eight samples from wells or springs in the principal aquifer suggest recharge after 1952. Two samples with tritium values dating prior to 1952 are from wells in the principal aquifer, and two are from wells west of the principal aquifer. Four samples were analyzed for 14C. Two of these wells were completed in the principal aquifer and two west of it. Correcting for partial carbon dilution, the age difference between the different areas is on the order of tens of thousands of years.

This research had two main objectives: quantify surface-water and groundwater interactions along a stream reach, and determine the hydraulic conductivity at the site where two reservoirs are proposed. The objectives of this research aim to help maintain stream ecology and increase surface water storage for recreational and industrial purposes. The stream reach, located in the Pascagoula River Basin of southeast Mississippi, begins at Lake Okatibbee and terminates at Pascagoula into the Gulf of Mexico. Four USGS continuous gauging stations provided more than forty years of stream discharge data for a hydrograph baselow-recession analysis, which determined the baseflow component within the stream. The analysis showed that baseflow decreases along the stream reach and increases again before reaching the Gulf of Mexico. Thirteen borehole samples were collected at the sites of the proposed reservoirs in George County, Mississippi to determine the hydraulic conductivity of the sediments, which showed high a hydraulic conductivity.

The population and industrial complexes of Choctaw County obtains much of its water from an aquifer system in the Tertiary age Wilcox unit of the Mississippi Embayment. Utilizing 20 years of physical chemistry (P-Chem) analysis, potentiometric groundwater records of Choctaw County public water wells as well as industrial P-Chem analysis and surface and ground water level records from an industrial complex, this study examined the changes to the hydrosphere that has taken place since 1995. Analysis of the hydrosphere shows that over the last 20 years, there has been a drop in the potentiometric surface of the Wilcox aquifer system. The analysis also shows changes in the P-Chem of the hydrosphere, changes such as a decrease in the concentration of free CO2 and chloride, and fluctuations of Alkalinity. Comparisons between groundwater records taken from the industrial complex and other locations around Choctaw County, show little variation in the physical chemistry.

Water conservation practices are being widely implemented to alleviate sediment and nutrient losses from agricultural land and unsustainable groundwater use for irrigation. Tailwater recovery (TWR) systems are conservation practices being implemented to collect and store runoff to reduce nutrient losses and provide a source of irrigation water. This collection of research is focused on evaluating TWR systems through the following actions: 1) investigate ability to reduce solids and nutrients delivery to downstream systems, 2) compare differences in solid and nutrient concentrations in surface water samples from TWR systems to irrigation water from a TWR systems; 3) determine the potential to irrigate water containing solids and nutrients; 4) quantify a water budget for TWR systems; 5) conduct cost and benefit analyses of TWR systems; and 6) analyze economic cost to reduce solids and nutrients and to retain water. Tailwater recovery systems did not significantly reduce concentrations of solids and nutrients; however, loads of solids, P, and N were significantly reduced by 43%, 32% and 44%, respectively. Mean nutrient loads per hectare available to be recycled onto the landscape were 0.20 kg ha-1 P and 0.86 kg ha-1 N. Water budget analyses show these systems save water for irrigation but were inefficient. Net present value (NPV) and benefit cost ratios were positive and >1 for producers who owned the land, but remained <1 if land was rented. However, beyond improvements to irrigation infrastructure, farms with a TWR system installed lost NPV of $51 to $328 per ha. Mean total cost to reduce solids using TWR systems ranged from $0 to $0.77 per kg, P was $0.61 to $3,315.72 per kg, and N was $0.13 to $396.44 per kg. The mean total cost to save water using TWR systems ranged from $189.73 to $628.23 per ML, compared to a mean cost of groundwater of $13.99 to $36.17 per ML. Mechanistically, TWR systems retain runoff on the agricultural landscape, thereby reducing the amount of sediment and nutrients entering downstream waterbodies and provide an additional source of water for irrigation; however, more cost-effective practices exist for nutrient reduction and providing water for irrigation.

Many types of contaminants of emerging concern (CECs), including per- and poly-fluoroalkyl substances (PFAS), have been found in leachate of operating municipal landfills. However, information on CECs in leachate of historic landfills (≥3 decades since closure, often lacking engineered liners or leachate collection systems) and the related risk posed from groundwater plumes discharging to nearby aquatic ecosystems is limited. In this study, 48 samples of leachate-impacted groundwater were collected from 20 historic landfills in Ontario, Canada. The CECs measured included artificial sweeteners (ASs), PFAS, organophosphate esters (OPE), pharmaceuticals, bisphenols, sulfamic acid, perchlorate, and substituted phenols. Several landfills, including ones closed in the 1960s, had total PFAS concentrations similar to those previously measured at modern landfills, with a maximum observed here of 12.7 μg/L. Notably elevated concentrations of several OPE, cotinine, and bisphenols A and S were found at many 30-60 year-old landfills. There was little indication of declining concentrations with landfill age, suggesting historic landfills can be long-term sources of CECs to groundwater. A full-year field study was performed on a 0.5-km reach of an urban stream receiving contaminated groundwater from nearby historic landfills. Elevated concentrations of ammonium, the AS saccharin, an indicator of old landfill leachate, and CECs (e.g., maximum total PFAS of 31 μg/L) in the shallow discharging groundwater were relatively stable across the seasons but were spatially restricted by hyporheic exchange and discharge of other groundwater. This indicates a patchy but long-term exposure for endobenthic organisms, which are rarely monitored. Stream water concentrations were more dilute, but increased markedly across the landfill stretch, and showed signs of increases in winter and after rain/snowmelt events. These findings provide guidance on which CECs may require monitoring at historic landfill sites and suggest how landfill monitoring programs could be improved to fully capture the risk to receiving water bodies. / Thesis / Master of Science (MSc) / Historic landfills are a known source of groundwater contamination. This study investigated whether these landfills contain new groups of chemicals, called contaminants of emerging concern (CECs), which are suspected to pose serious environmental and human health risks. This study found many CECs at high concentrations in most of the 20 historic landfill sites investigated, even those closed up to 60 years. A full-year investigation at one historic landfill site showed that organisms living in the sediments of a nearby stream are exposed to high concentrations all year long. Concentrations in the stream increased as it flowed past the landfill, and may be higher in winter and after rains, times monitoring is rarely done. The elevated concentrations of harmful contaminants in this water are potentially threatening the stream ecosystem. Operators of historic sites should consider testing for CECs and ensure that monitoring strategies accurately evaluate the risk posed to the environment.