The study was conducted to monitor pesticide residues in groundwater of two agriculturally intensive regions of Alberta, to determine the occurrence of pesticide residues in soil and groundwater of an experimental plot in southern Alberta, and to investigate the influence of land management factors and soil depth on pesticide residues in soil. A total of 440 groundwater samples were collected in three years (2013-2015) and analyzed for the presence of 142 pesticides using Liquid-liquid Extraction (LLE) in combination with Gas Chromatography- Mass Selective Detector (GC-MSD) and Gas Chromatography - Tandem Mass Spectrometry (GC-MS/MS). Ten herbicides, seven insecticides, and six fungicides were detected. Herbicides 2,4-D, MCPA, and clopyralid were the most frequently detected, and the only pesticides consistently detected every year in both regions. Pesticides were detected more frequently in summer and fall compared to spring. 4.5% of the samples were contaminated with more than one pesticides. No pesticides exceeded the Guidelines for Canadian Drinking Water Quality. Similarly, a total of 213 groundwater samples (December 2014-November 2015) and 61 soil samples (in December 2014) in duplicates were analysed from the experimental plots in Lethbridge. Soil samples were collected at various depths (0-75 cm) and analyzed for the presence of 130 pesticides. A linear mixed effect model was fitted to determine the effect of soil depth, cropping systems and manure amendments on pesticide concentration in soil. In groundwater, bentazone, 2,4-D, and MCPA occurred most frequently and pesticide detection frequency varied seasonally with greater detections in July and September compared to other months. 37 different pesticide compounds were detected, and DDT isomers, 2,4-D, difenoconazole, MCPA and trans-heptachlor epoxide accounted for 85% of all detections. p,p’-DDE, 2,4-D, p,p-DDT, difenoconazole and MCPA occurred throughout the soil column and all of these except p,p-DDT were detected in underlying groundwater. Bentazone was found in groundwater throughout the year but not in soil. A greater number and higher concentrations of pesticides were found in soil. However, not all of them leached to groundwater. Soil depth and cropping system were significantly associated with total pesticide and total DDT concentration in the soil. Manure amendments had no affect pesticide concentrations. / May 2017

Source water protection is a key component of the multiple barrier approach to drinking water. The management of contamination within source water ecosystems is associated with many benefits but also several challenges. By its very nature, source water protection is site specific and requires the cooperation of numerous watershed stakeholders to ensure sufficient financial resources and social will. This work focused on two critical aspects of source water protection: 1) The facilitation of effective communication to promote cooperation among watershed stakeholders and aid in public education programs. A drinking source water quality index presents a potential communication and analysis tool to facilitate cooperation between diverse interest groups as well as represent composite source water quality. I tested the effectiveness of the Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) in capturing expert assessments of surface drinking source water quality. In cooperation with a panel of drinking water quality experts I identified a core set of parameters to reflect common Canadian surface source water concerns. Based upon existing source water guidelines, drinking source water target values were drafted for use in the index corresponding to two basic treatment levels. Index scores calculated using the core parameter set and associated source water target values were strongly correlated with expert assessments of source water quality. Amended with a modified index calculation procedure to accommodate parameters measured at different frequencies within any particular study period, the CCME WQI provides a valuable means of monitoring, communicating, and understanding surface source water quality. 2) The application of source water protection strategies to the appropriate spatial scale in order to manage contaminants of concern in a cost effective manner. Using data gathered from 40 Canadian rivers across 4 western Canadian ecozones I examined the spatial scales at which landuse was most closely associated with drinking source water quality metrics. Linear mixed effects models revealed that different spatial areas of landuse influence drinking source water quality depending on the parameter and season investigated. Microbial risk, characterized using E. coli measures, was only associated with landuse at the local spatial scale. Turbidity measures exhibited a complex association with landuse suggesting that the landuse areas of greatest influence can range from the local to the watershed scale. Total organic carbon concentrations were only associated with landuse characterized at the entire watershed scale. The validated CCME WQI was used to provide a composite measure of seasonal drinking source water quality but did not provide additional information beyond the analyses of individual parameters. These results suggest that entire watershed management is required to safeguard drinking water sources with more focused efforts at targeted spatial scales to reduce identified risk parameters. The source water protection tools and knowledge that I present have immediate application within Canada. Practitioners must be aware of the limitations of the CCME WQI however it provides a validated means of communicating complex source water quality information to non-specialized end users. Combined with the scale dependency of landuse-source water relationships that I elucidated, water quality managers can target contaminant reduction strategies in a more cost-effective manner and relay water quality status and trends to concerned groups. / Graduate

The objective of this study was to develop water quality guidelines for poultry reared under South African conditions and production systems. This was achieved by a modeling approach that was based on a survey of water used by poultry producers throughout the country. Potentially hazardous constituents identified were – Sodium, Magnesium, Chloride, Sulphate, Nitrate, Calcium and Phosphorus. Three experiments were conducted to test these constituents’ effects on poultry production. Experiment 1 examined the influence of different levels of magnesium, sodium, sulphate and chloride in the drinking water of layers and the effect thereof on their production. The study showed that 12 different combinations of Mg, Na, Cl and SO4 had no significant effect on growth, food and water intake, and egg production or egg quality. Poultry producers in areas with naturally high levels of these minerals in their ground water can therefore continue to function successfully if the concentrations present are up to 250 mg/l of Mg, 500 mg/l of Cl, 500 mg/l of SO4 and 250 mg/l of Na. Experiment 2 examined the effect of elevated levels of NaNO3 in the drinking water of layers and broilers. No negative effects on broiler production and growth were observed. The only mineral ion to show a significant effect on performance was nitrate, with lower nitrate concentrations in well water being associated with better performance. Experiment 3 examined the effects of Ca and P in the drinking water on egg production, egg quality, bone integrity and shell strength. The results showed that water can be a valuable asset to increase eggshell integrity, but waterline maintenance may be increased because of the tendency of calcium to precipitate. Water should be seen as a dietary source of minerals (Ca + P) and should be taken into consideration when nutrient specifications are set for feed formulations to be used in the various poultry production systems. The preceding results served as basis for developing a modeling approach to water quality guidelines for poultry. / Thesis (PhD (Animal Science))--University of Pretoria, 2008. / Animal and Wildlife Sciences / unrestricted