The focus of the National Water Act (Act 36 of 1998) is on the sustainable utilization of our water resources. This is to be achieved through the implementation of an integrated resource protection approach, which is aimed at ensuring that a balance is maintained between the protection and utilization of our countries water resources. This approach sets Resource Quality Objectives (RQOs) that define acceptable levels of water resource protection. The acceptable risk of damage to the ecological integrity of a water resource will play an important role in the setting of these objectives, e.g. for a water resource of lower importance a higher risk would be acceptable with the subsequent setting of RQOs at less stringent levels. A desktop Resource Directed Measures (RDM) determination has already been performed for the Luvuvhu River in the Northern Province. There was decided to evaluate a facet of this desktop study, namely the Present Ecological Status (PES), by utilising the South African Scoring System version 4 (SASS4) and the Integrated Habitat Assessment Method (IHAS) biomonitoring techniques. It was then possible to compare the desktop determined PES to the PES determined from the information provided by the biomonitoring techniques. Ultimately, SASS4 verified the reliability of the RDM methodology Further, to facilitate the introduction of Ecological Risk Assessment (ERA) into South Africa there was looked at how and where SASS4 and IHAS would fit into the various phases of the ERA process. SASS4 serves as an indication of the extent of an impact, and in conjunction with an ERA, would provide the means with which to determine causality. A retrospective ERA based on data obtained from SASS4 and a concomitant habitat assessment method will thus provide a valuable tool for the protection of our water resources. / Prof. G.J. Steyn

This research develops an algorithm for solving a class of multiple objective decision problems. These problems are characterized by continuous policy variables, nonlinear constraints, and nonlinear criterion functions. Our underlying philosophy is that of the Gestalt psychologists-- we cannot separate the problem and its solution from the environment in which the problem is placed. The decision maker is necessarily a part of this environment, thus implying that he, as an individual, must be part of the solution of the problem. Another central assumption in this research is that there is not an "optimal" answer to the problem, only "satisfactory" solutions. The reasons for this are based partly on the insensitivities of the body to minute changes and to the insensitivity of our preferences within certain ranges of acceptance. In addition, we assure that the individual is capable of solving decision situations involving a maximum of about 10 goals and that he operates upon them in some sort of serial manner as he searches for a satisfactory alternative. The serial manner is a reflection of his current ranking of the goals. Based on these assumptions we have developed a cyclical interactive algorithm in which the decision maker guides a search mechanism in attempting to find a satisfactory alternative. Each cycle in the search consists of an optimization phase and an evaluation phase, after which the decision maker can define a new direction of search or terminate the algorithm. The optimization phase is based on a linearization technique which has been quite effective in terms of the problems we have attempted to solve. It is capable of solving general nonlinear programming problems with a large number of nonlinear constraints. Although the constraint set must be convex in order to guarantee the location of a global optimum, we can use the method on concave sets recognizing that we may find only a local optimum. An extensive synthetic case study of a water pollution decision problem with 6 conflicting goals is provided to demonstrate the feasibility of the algorithm. Finally, the limitations of the research are discussed. We tentatively conclude that we have developed a method applicable to our research problem and that the method can be applied to "real world" decision situations.

Magister Scientiae (Integrated Water Resource Management) / Chemical pollution of freshwater is a worldwide environmental problem; eutrophication, heavy metals and salinity are amongst the most widely used indicators of pollution. The aim of this study was to assess the status of nutrients, heavy metals and salinity, and the seasonal variation int he Bottelary River. / South Africa

No description available.

Concern over sediment toxicity has increased the need for toxicity test information with organisms that inhabit sediments. Oligochaetes are exposed to toxicants through feeding and direct body contact with aquatic sediments. Chronic testing with oligochaetes has historically focused on tubificids with test lengths of one year or more to encompass several generations. Most naidid oligochaetes have generation times of three to seven days and could provide chronic information in a matter of weeks. The cosmopolitan distributed naidid, Pristina leidyi, was evaluated for use as a toxicity test organism. Results of research conducted includes culture methods, effects of temperature on reproduction, growth rates in a reference sediment, acute toxicity tests, and chronic toxicity tests.

Critical water resources, such as groundwater, are undergoing a period of intense and global environmental change, driven by climate change, anthropogenic impacts and exploitation, and perturbations to interactions of fundamental processes that are affected by hydrological, mineralogical and biogeochemical factors. Arsenic contamination is a significant threat to these water resources and the populations who depend on them, yet there are few studies directly linking water quality with changes in hydrology and geochemistry in sediments on varying scales. My research explores environmental variability in hydrology and redox processes that regulate soluble arsenic concentrations at the pore scale (µm to mm), and develops methods of upscaling these mechanistic studies to understand heterogeneity in groundwater arsenic levels and their impacts on public health at larger scales (a couple of meters to hundreds of kilometers). Specifically, my research examines the interaction of redox processes in the Earth’s subsurface that drive the release of arsenic into groundwater. Naturally-occurring, or geogenic, arsenic contamination is the main source of arsenic release into groundwater that affects human health, with possible anthropogenic exacerbation of this natural contamination. Throughout this dissertation, I have developed a suite of data-driven approaches to understand and quantify the highly variable factors that underlie the mechanisms of geogenic arsenic release into groundwater and its migration in the environment. In Chapter 1, I investigate the effects of hydrologic perturbations on formerly uncontaminated aquifers that release arsenic due to increased groundwater pumping in the Red River Delta, Vietnam. To compare the effect of hydrologic processes to measured groundwater arsenic concentrations, I used Monte Carlo simulations in an end-member mixing model and quantified fraction of different recharge sources into an aquifer based on stable water isotopes. I find that changing flow patterns due to groundwater abstraction have increased the extent of arsenic release into groundwater and also changed the location of where arsenic contamination originates. In Chapter 2, I characterize iron mineralogy associated with arsenic release through sampling of sediment cores across a lateral redox gradient in Vietnam with extensive spectroscopy measurements. Through hierarchical cluster analysis on this data set of X-ray absorption spectroscopy (XAS) measurements of borehole cuttings paired with dissolved groundwater measurements, I reveal signatures of iron mineral reduction that could cause or exacerbate arsenic release. This was upscaled to other deltaic aquifers in South and Southeast Asia based on groundwater data to identify aquifers at risk of arsenic release. I showed that the extent of older and previously pristine aquifers that have been contaminated may have been misclassified and thus underrepresented in deltaic aquifers throughout South and Southeast Asia, disrupting the assumption that older and deeper aquifers are oxidized and thus guarded against arsenic release. In Chapter 3, I use process-based reactive transport modeling of a laboratory-scale experiment to mechanistically explain the infiltration of contaminated water into uncontaminated aquifers and find that arsenic contamination cannot be explained by the commonly invoked mechanism of iron reducing bacteria only, but instead relies on sulfate reduction and complexation of aqueous arsenic in solution. The role of sulfate reduction in mobilizing arsenic in groundwater is in stark contrast to and undermines the previous use of sulfate reduction as strategy for arsenic remediation. Finally, in Chapter 4, I quantitatively examine the processes that release arsenic across different arsenic-impacted aquifers, based on the relationships between redox status of iron and arsenic mineralogy and groundwater concentrations. Synthesis of X-ray absorption spectra of the deltaic aquifers of Southeast Asia and the glacial aquifer system in the Northern United States shows that arsenic release occurs in similar geochemical environments in both systems, and is highly generalizable via statistical and unsupervised machine learning approaches. This dissertation demonstrates that common assumptions behind geogenic arsenic release must be tested: from which aquifers are low in arsenic to the commonly assumed mechanism of arsenic release by iron reducing bacteria. These findings also reveal that the extent of anthropogenic impact on geogenic arsenic contamination is detectable: from changes in recharge sources to changes in mineralogy that affect arsenic concentrations and human health. The next step is to use these data driven and machine learning approaches to quantify the vulnerability of affected aquifers, to mitigate the risk of those currently reliant on contaminated groundwater, to reduce the risks of future contamination and, ultimately, to protect human health.

Syftet med detta examensarbete är att studera vilka vattenföroreningar som uppstår i samband med tunnelbyggen, vilka krav som miljömyndigheterna ställer i sammanhanget och vilka reningsåtgärder som har vidtagits för att möta dessa krav samt att föreslå ytterligare reningsåtgärder. Arbetet har utförts som en jämförande litteraturstudie av befintlig dokumentation för tolv olika tunnelbyggen. Vid ett tunnelbygge används stora mängder kylvatten till bergborrningsmaskiner. Detta vatten avleds tillsammans med inläckande grundvatten och släpps efter rening ut till en recipient. Föroreningarna i vattnet från tunneln består i huvudsak av olja, suspenderade partiklar och lösta kväveföreningar. I dagsläget används mekanisk rening för att reducera mängden olja och suspenderade partiklar i vattnet. Kväveutsläppet minskas framförallt genom förebyggande åtgärder för att undvika kvävehaltigt sprängämnesspill. Dagens reningsmetoder ger en betydande minskning av utsläppen. Utsläpp av förorenat vatten från ett tunnelbygge kan ge upphov till temporär miljöpåverkan i recipienten. Miljömyndigheternas krav på begränsningar av utsläpp från tunnelbyggen har i de flesta fall kunnat efterföljas väl. Medianhalten för suspenderat partikulärt material i renat vatten från olika tunnelbyggen varierade mellan 210 mg/l och 485 mg/l. Uppmätta medianvärden för oljehalt varierade mellan 0.28 mg/l och 1.3 mg/l. Medianhalten för olika kväveföreningar i varierade mellan 3.2 mg/l och 100 mg/l. Detta betyder att mellan 0.3 % och 9 % av det kväve som ursprungligen fanns i sprängämnet har hamnat i processvattnet. Enstaka mätvärden för totalkväve, olja och suspenderat material kan visa på upp till 100 ggr högre halt än medianvärdet. l examensarbetet jämförs mängden utsläppta föroreningar till vatten från de olika tunnelbyggena med utsläpp till vatten från vägar, båtar och jordbruk. Ett tunnelbygge leder till utsläpp av samma storlek som det årliga utsläppet från en enstaka bondgård, en motorbåt eller dagvattnet från en kortare motorvägsträcka, med avseende på kväveläckage, oljeutsläpp respektive innehåll av suspenderade partiklar. l examensarbetet beskrivs existerande reningsåtgärder och ges förslag på ytterligare åtgärder som kan vidtas för att minska utsläppen av vattenföroreningar från tunnelbyggen. De föreslagna åtgärderna behandlar optimering av reningsanläggningar, förbättrade kontrollprogram och utsläppsförebyggande insatser. En diskussion förs om möjligheten att förbättra miljöövervakningen vid utsläpp av tunnelvatten genom att ersätta dagens stickprovtagningar med automatiserad kontinuerlig flödesproportionell mätning. / The aim of this thesis is to study which types of water pollution are released during tunnel construction, what demands do the environmental protection authorities have regarding such pollution, what has been done to meet those demands, and finally to suggest additional treatment measures. The work has been performed as a literature study comparing twelve different tunnel projects. When a tunnel is built a lot of water is used to chill the rock-drilling equipment. This water is diverted together with water that originates from an inflow of groundwater, and is released to a recipient after treatment. The water pollution originating from the tunnels consists mainly of oil, suspended material and dissolved nitrogen compounds. Mechanical water treatment measures are used today to reduce the amount of oil and suspended material in the water. Measures are currently taken to limit the accidental release of nitrogen from undetonated explosives to the water. Water treatment today considerably reduces the discharge of pollutants. Discharge of polluted water from tunnel construction can cause temporary environmental effects in the recipient. The demands from the environmental protection authorities for reduction of pollution from tunnel construction have mostly been met. The median content for suspended material in treated water from different tunnel projects varies between 210 mg/l and 485 mg/l. Median content for oil varies between 0.28 mg/l and 1.3 mg/l. The median content for dissolved nitrogen compounds in the water varies between 210 mg/l and 485 mg/l. This means that between 0.3 % and 9 % of the original nitrogen content in the explosives was released in the water. Occasional measurements of nitrogen, oil and suspended material can reach a hundred times higher than the median value. In this thesis, a comparison is made between the amount of pollutants that is discharged into water from tunnel construction and the discharge from roads, boats and agriculture. The total amount of water pollution from a tunnel project is of the same magnitude as the annual discharge from a single farm, a motorboat or the runoff from a short stretch of motorway, regarding nitrogen leakage, oil pollution and content of suspended material respectively. The thesis describes existing water treatment measures and suggestions are made about possible improvements to reduce emissions from tunnel constructions. The suggestions deal with optimisation of water treatment systems, improved surveillance programs and prevention of pollution discharge. A proposal is made about improving environmental surveillance by replacing the currently used random sampling with continuous sampling that is in proportion to discharge.

<p>Osnovni cilj teze bio je razvoj nove i inovativne senzorske metode za merenje neorganskih parametara u površinskim vodama i vodama zatvorenih bazena. Kolorimetriski fiber-optički senzor (KFOS) je osposobljen za merenje pet parametara u površinskoj vodi (ortofosfata, ukupnog hlora, hroma (VI), nitrita i sulfata) i za merenje dva parametra u bazenskim vodama (rezidualnog hlora i ukupnog hlora). Pored prilagođavanja nove metode urađena je i analiza kvaliteta reke Dunav u Novom Sadu na osnovu čega su odabrani parametri za merenje sa KFOS metodom.</p> / <p>The main goal of the thesis was to develop a new and innovative sensor method for measuring inorganic parameters in surface waters and waters of indoor pools. The Colorimetric Fiber Optic Sensor (CFOS) is capable for measuring five parameters in surface water (orthophosphate, total chlorine, chromium (VI), nitrite and sulfate) and for measuring two parameters in pool water (residual chlorine and total chlorine). In addition to adjusting the new method, an analysis of the quality of the Danube River in Novi Sad was performed and based on which parameters for measuring with the KFOS method were selected.</p>

A behavioral model for acute responses in bivalves, was developed using time series analysis for use in a real-time biomonitoring unit. Stressed bivalves closed their shell and waited for the stressful conditions to pass. Baseline data showed that group behavior of fifteen bivalves was periodic, however, individuals behaved independently. Group behavior did not change over a period of 20 minutes more than 30 percent, however, following toxic exposures the group behavior changed by more than 30 percent within 20 minutes. Behavior was mathematically modeled using autoregression to compare current and past behavior. A logical alarm applied to the behavior model determined when organisms were stressed. The ability to disseminate data collected in real time via the Internet was demonstrated.

Growth of mussels under laboratory conditions was examined under various food regimes in different water types and temperatures. Growth was less than would be useful as an indicator and comparisons with field exposures were of minimal value. The effects of organophosphates on bivalves were examined via toxicity tests, tissue concentration, and by controlling exposure through the use of physical constraints. Upper temperature tolerance of both bivalve species was examined with respect to different acclimation temperatures and organophosphate exposures. Deviations from control exposures occurred at some temperatures. Copper effectively lowered the mean heat coma temperatures of C. fluminea at some concentrations, however, chlorine exposures did not alter heat coma temperature.