Surface water and sediments from the St. Lawrence River system (Quebec region) were analysed for genotoxicity using nonlinear SOS Chromotest parameters, as well as for their chemical concentrations of polycyclic aromatic hydrocarbons and heavy metals. Additionally, sediments chlorobenzenes, polychlorinated biphenyls, organochlorinated pesticides, ammonia and nitrites concentrations were determined. Organic contaminants were extracted dichloromethane. For surface water, fifteen extracts of filtered water and seven of particulates, and for sediments, one extract of pore water and three of particulates proved to be weakly genotoxic. All but one of the genotoxic responses observed in the surface water were obtained from samples taken from the highly industrial portion of the St. Lawrence River system, with the strongest responses observed in Lake St-Louis. Surface water genotoxicants partitioning favors the particulate fraction. Bottom particulates genotoxicity was one thousand fold weaker than suspended particulates. Additionally, whole sediments were extracted with a 10% dimethylsulfoxide-saline solution. Genotoxicity of hydrophilic contaminants was detected in all extracts. The observed distributions of genotoxicity values did not correlate with observed concentrations of demonstrated SOS inducers, mutagens and/or carcinogens, nor with the presence of other toxic chemicals.

Bioretention systems are best management practices (BMPs) that make use of the biogeochemical processes within a forest-type ecosystem to provide at-source stormwater retention and pollutant removal. Laboratory studies and field monitoring have shown great potential for water quantity and quality control through the use of bioretention, but reported nutrient removal has been inconsistent between these systems. In particular, the processes involved in the cycling of phosphorus within bioretention systems are not clearly understood. Some studies report high phosphorus removal from bioretention systems, while phosphorus leaching was observed in other systems. Phosphorus is a macronutrient required by all forms of life. It is also an important water pollutant, as it controls algal growth in most freshwater environments. High phosphorus loadings to these aquatic ecosystems can lead to eutrophication, which has significant ecological, environmental and economical impacts. The Bioretention Phosphorus Removal Model (BPRM), an event-based one-dimensional finite difference model, was developed to simulate phosphorus removal in bioretention systems. The model includes four completely-mixed layers to simulate hydrologic processes as well as both soluble and particulate phosphorus transport in a bioretention system. Model processes include evapotranspiration, infiltration, overflow, exfiltration to native soils, underdrain discharge, soluble phosphorus sorption and vegetative uptake, and particulate phosphorus capture. Monitoring data collected by the Toronto and Region Conservation Authority (TRCA) at a bioretention system installed on Seneca College’s King City campus, in Ontario, Canada, was used to evaluate the performance of BPRM. The model was found to overestimate total underdrain discharge volumes, but total phosphorus concentration and mass predictions were found to be useful for design purposes. BPRM correctly predicted phosphorus leaching from the Seneca College bioretention system for all storm events considered but one. The model can be used by practitioners to evaluate the potential for phosphorus leaching in a bioretention system. A detailed sensitivity analysis revealed that BPRM phosphorus transport predictions are particularly sensitive to the drainage properties of bioretention soils, which highlights the importance of hydrologic transport processes for water quality control in bioretention systems. Modelling results suggested that soluble phosphorus desorption from bioretention soils was responsible for phosphorus leaching from the Seneca College bioretention system. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-09-25 17:00:03.173

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<p>This study forms part of a broader project co-funded by the Water Research Commission (WRC), and CSIR Parliamentary Grant (PG) and Strategic Research Panel (SRP) research grants, aimed at surveying selected water resources within the 19 Water Management Areas in South Africa. Furthermore, it aims at determining the concentrations of Hg and MeHg in various environmental compartments collected from priority water resources, to identify the potential Hg hotspots, and to assess the degree of compliance with national and international guidelines. Mercury concentrations in the environment have increased globally and this has caused much anxiety in terms of the adverse effects it has on aquatic ecosystems, their organisms, and the communities they sustain. Human health risks associated with the consumption of fish elevated containing Hg concentrations have received minimal attention particularly in South Africa. It is imperative that any potential adverse impacts of Hg on aquatic ecosystems, and the subsequent impacts on human health, be investigated.</p>

The status of the Baynespruit bacteriological water quality is very alarming - E-coli concentrations have far exceeded the allowable limit of both local and international guidelines for more than a decade, namely 2000-2010. Concentrations of indicator bacteria have been recorded as high as 2419000 cfu/100 ml, whereas guideline levels of E-coli for recreational contact are about 130 cfu/100 ml. In this study, statistical analyses were carried out on data from two sampling points to clarify the seasonal changes and the variability of the pollution. Cross-correlation analyses showed that there was no significant correlation between E-coli concentrations and rainfall in the uMsunduzi catchment. There was also only a weak correlation between the two sampling points which suggests the existence of unregulated sources of pathogenic water pollution between the sampling locations that are independent of the effect that rainfall has on dilution and dispersion of pollution. The data indicates that the population living along the Baynespruit has about a 2% risk of contracting gastrointestinal illness as a result of the pollution in the stream. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.

The growth of industrialization has increased waste pollution, especially water pollution. Industries and individuals produce pollutants that are discharged into waters. Uncontrolled water pollution results in health hazards to human beings, animals and other living things. Thus there is a need to impose water pollution control measures which can reduce pollution to an extent where very little pollutants are discharged into waters. Many states have enacted statutes for controlling water pollution, as they believe this is the best way to impose measures to achieve the safety of waters. Legislations impose measures, such as a permit and its conditions, that must be respected to discharge pollutant or trade effluent into waters, otherwise the discharger becomes a polluter and liable to criminal sanctions. Statutes create offences and penalties for water polluters. They provide fines or imprisonment, or both, and severely punish a subsequent offender. In most countries, a continuing offence is criminalised. Corporations, as well as corporate officers, are punished for the offence of polluting waters or other environmental crimes. This is because environmental law does not allow corporate officers to hide behind the legal structure of the corporation. Some measures such as remediation or clean-up orders are implemented before a prosecution is engaged, in order to ensure the protection of the environment. Environmental audit or service orders emphasise the protection of the environment and may prevent future pollution of waters. Environmental service orders rectify one of the criticisms of fine or imprisonment, in that they fail to restore the environment to its previous condition. Most environmental crimes are caused not by a deliberate intention or negligence, but by poor or ineffective management systems. As a result, environmental audit orders may be used to detect and correct an inappropriate management system. Environmental law should be a user-friendly and prosecution must be used as a last resort. This dissertation examines offences and penalties for water pollution in South Africa, the United Kingdom, the United States of America and Australia and offers a comparative analysis and recommendations for South Africa. These countries have been selected not only because they are developed and tend to have best laws, but they are also located in different continents. The examination and analysis of how they provide offences and penalties for water pollution gives a chance to South Africa to find recommendations on how it may improve its legislation and maintain its water quality. / Thesis (LL.M)-University of KwaZulu-Natal, Pietermaritzburg, 2008

Microorganisms are increasingly used in toxicological studies to determine potential environmental impacts of xenobiotic compounds. A multi-stage laboratory model was developed to facilitate the examination of environmental impacts of selected pollutants on fundamental cycling processes inherent to aquatic ecosystems, namely, the degradation of organic substances and nitrogen transformations under aerobic conditions. A microbial association representative of riverine ecosystems was enriched for, isolated and cultured within the model. Characterisation of the microbial association were undertaken. Scanning electron microscopy and bright field microscopy revealed that a diverse heterogenous community of microorganisms had established within the model. Successional metabolic events, namely organic carbon catabolism, ammonification of organic nitrogen and the process of nitrification were differentiated in time and space with the microbial association integrity still being retained. The establishment of a microbial association within the model was primarily dependent on: dilution rates, specific growth rates and interactions between microorganisms and the prevailing environmental conditions. Growth-rate independent populations of microorganisms established within the model and were thought to contribute significantly to the metabolic processes within the model. Nitrifying activity was identified as a rate-limiting process within the model. Following separation of metabolic events, the ecotoxicological impacts of phenol and 2,4-dichlorophenol on the association were assessed. The biological oxidation of ammonia through to nitrate (nitrification) was found to be a sensitive indicator of perturbation. The model was found to be suitable for testing both acute and chronic intoxication by pollutant compounds as well as for biodegradation testing and the possible evaluation of ecotoxicological impacts of wastewater treatment plants. The main disadvantages of the model arose from its operational complexity, its empirical nature and its impracticality for screening large numbers of compounds. A bioassay based on the inhibition of ammonium oxidation was developed in order to fulfil the requirements for a simple and rapid test protocol for the initial screening of perturbant compounds. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.

We hypothesized that populations exposed to chronic levels of genotoxins for many generations in situ will accumulate latent heritable genetic damage leading to increases in mutational load and decreased population fitness. Common pulmonate snails (Lymnaea stagnalis) were collected from three sites that differed in pollution level [Manitoulin Island (reference), Beauharnois (moderate pollution), and Varennes (highly polluted)]. These organisms have a rapid generation time and are capable of self-fertilization. Fitness indicators were clutch size, survival (hatching to day 30) and growth (length from hatching to day 90). Recessive deleterious mutations that have accumulated through time are masked as snails preferentially outcrossed, but are expressed when snails self-fertilize. Results obtained by comparing fitness components of snails derived from selfing and outcrossing experiments showed that in sites with higher levels of pollution inbreeding depression increased for clutch size and survival. Results for growth rate were similar to those for clutch size and survival in the two least polluted sites, but not for the most polluted site, due possibly to biased mortality of smaller snails at this site. After correction for size biased mortality, the growth estimates showed patterns similar for the two polluted sites when compared to the reference site. This study suggests that long-term in situ exposure to genotoxic pollution may effect population fitness due to the accumulation of latent heritable genetic damage.