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Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Industrial development within Canada's boreal zone has increased in recent decades. Forest management activities, pulp and paper operations, electric power generation, mining, conventional oil and gas extraction, nonconventional oil sand development, and peat mining occur throughout the boreal zone with varying impacts on water resources. We review impacts of these industries on surface water, groundwater, and wetlands recognizing that heterogeneity in the dominance of different hydrologic processes (i.e., precipitation, evapotranspiration, groundwater recharge, and runoff generation) across the boreal zone influences the degree of impacts on water resources. Through the application of best management practices, forest certification programs, and science-based guidelines, timber, pulp and paper, and peat industries have reduced their impacts on water resources, although uncertainties remain about long-term recovery following disturbance. Hydroelectric power developments have moved toward reducing reservoir size and creating more natural flow regimes, although impacts of aging infrastructure and dam decommissioning is largely unknown. Mineral and metal mining industries have improved regulation and practices, but the legacy of abandoned mines across the boreal zone still presents an ongoing risk to water resources. Oil and gas industries, including non-conventional resources such as oil sands, is one of the largest industrial users of water and, while significant progress has been made in reducing water use, more work is needed to ensure the protection of water resources. All industries contribute to atmospheric deposition of pollutants that may eventually be released to downstream waters. Although most industrial sectors strive to improve their environmental performance with regards to water resources, disruptions to natural flow regimes and risks of degraded water quality exist at local to regional scales in the boreal zone. Addressing the emerging challenge of managing the expanding, intensifying, and cumulative effects of industries in conjunction with other stressors, such as climate change and atmospheric pollution, across the landscape will aid in preserving Canada's rich endowment of water resources. [ABSTRACT FROM AUTHOR]

Over the past decade, plastic pollution has been documented throughout the Laurentian Great Lakes basin. Here, we demonstrate the application of a published ecological risk assessment and management framework for microplastics in aquatic environments by comparing proposed thresholds for risk to monitoring data from the Great Lakes region. Our results suggest that there may be measurable risks from microplastics to aquatic communities in parts of the Great Lakes where current concentrations are relatively high. For example, 89% of surface water samples collected across the region exceed the proposed risk thresholds for food dilution toxicity. However, all sediment samples remain below the proposed risk thresholds. Accordingly, we suggest that an appropriate and necessary next step for management may include convening a working group of local experts to develop an ecological risk assessment and management framework for the region comprising thresholds of concern for microplastics in surface water and sediment. Ultimately, microplastic pollution should be addressed in the Great Lakes Water Quality Agreement to ensure coordinated and sustained efforts are taken by the governments of Canada and the United States to reduce their release and impact. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Fisheries & Aquatic Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Process water treatment has become a critical issue for Canada’s oil sands industry. Continuous recycling of tailings pond water (TPW) has contributed to a decline in water quality that has consequences for bitumen recovery, water consumption, and reclamation efforts. Potential roles for water treatment were assessed through a review of process water quality and toxicity data from two long-term oil sands operations. Target pollutants were identified according to exceedances of environmental and industrial water quality guidelines. From 1980 to 2001, the salinity of TPW increased at a rate of 75 mg/L per year. Recent increases in hardness, sulphate, chloride, and ammonia have raised concerns over scaling and corrosion. Naphthenic acids released during bitumen extraction are the primary source of toxicity in TPW. Biodegradation of naphthenic acids has been demonstrated in pond experiments; however, recalcitrant compounds may contribute to chronic toxicity in reclaimed environments. Water treatment objectives established in this review provide benchmarks for the selection of candidate water treatment technologies. Le traitement des eaux de procédé est devenu une question très importante pour l’industrie canadienne des sables bitumineux. Le recyclage continu de l’eau des parcs à résidus (TPW) contribue à diminuer la qualité de l’eau, ce qui impacte la récupération du bitume, la consommation d’eau et les efforts de remise en état. Les rôles potentiels du traitement de l’eau ont été évalués par un examen de la qualité de l’eau de procédé et des données de toxicité pour deux exploitations à long terme de sables bitumineux. Les polluants ciblés ont été identifiés selon les excédents aux lignes directrices environnementales et industrielles sur la qualité de l’eau. Entre 1980 et 2001, la salinité de la TPW a augmenté à un rythme de 75 mg/L par an. Les récentes augmentations en dureté, en sulfates, en chlorures et en ammoniac ont soulevé des inquiétudes quant à l’incrustation et la corrosion. Les acides naphténiques libérés durant l’extraction du bitume sont la principale source de toxicité dans la TPW. La biodégradation des acides naphténiques a été démontrée dans des expériences dans les parcs à résidus; toutefois, les composés récalcitrants peuvent contribuer à une toxicité chronique dans les environnements remis en état. Les objectifs du traitement de l’eau établis dans cette revue fournissent des points de référence pour la sélection des technologies de traitement des eaux. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Fisheries & Aquatic Sciences is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Presents a study of spatial and temporal variation of distributed water quality in municipal drinking water utilities in Quebec. Key parameters responsible for the differences between the groups of utilities; Capacity of studied utilities to handle the acute disease risk associated with microorganisms; Parameters upon which it may be possible to act to achieve better water quality in each of the utility groups; Comparisons of the characteristics of water quality at the source; Chlorination conditions in the plant; Water quality from the entrance to the extremity of the distribution system.

Examines the scaled chrysophytes preserved in modern and fossil sediment samples from lakes in Ontario. Evaluation of the changes in water quality; Determination of chrysophyte distributions using redundancy analysis; Introduction of a multi-indicator reconstruction model.

Thousands of lakes in northeastern Ontario, Canada, have been acidified by sulphur deposition associated with emissions from the Sudbury area metal smelters. However, water quality improvements including increased pH and reduced sulphate concentrations have followed large reductions in Sudbury emissions that were implemented, beginning in the 1970s. Substantial decreases in Ca concentrations accompanied these other changes in lakewater chemistry. Monitoring of 38 lakes 20–128 km from Sudbury showed declines in Ca concentrations, averaging 2.7 µeq·L[sup –1] ·year[sup –1] , over the period 1981–1999. Declines were particularly apparent during the 1990s, averaging 3.8 µeq·L[sup –1] ·year[sup –1] . Paleolimnological reconstructions of the long-term Ca patterns in six lakes suggest that general lakewater Ca declines occurred through much of the 20th century. Comparison of recent measured Ca concentrations in 16 lakes with diatom-inferred pre-industrial Ca concentrations indicates that overall decreases in Ca have been large, averaging 74.6 µeq·L[sup –1] or 46%. Long-term Ca patterns may reflect a combination of factors including climatic changes, forest harvesting activities, and leaching by acid deposition, the effects of which we can not separate. Calcium declines have biological implications that will need to be considered in the development of appropriate targets as these lakes continue to recover from acidification.Des milliers de lacs du nord-est de l'Ontario, Canada, ont été acidifiés par les dépôts de soufre provenant des émissions des fonderies de la région de Sudbury. Cependant, les réductions importantes des émissions depuis les années 1970 ont entraîné une amélioration de la qualité de l'eau et, en particulier, un accroissement du pH et une diminution des concentrations de sulfates. Des réductions importantes des concentrations de Ca ont accompagné ces changements dans la chimie des eaux des lacs. Le suivi de 28 lacs situés à des distances de 20 à 128 km de Sudbury indique des déclins dans les concentrations de Ca d'en moyenne 2,7 µeq·L[sup –1] ·année[sup –1] de 1981 à 1999, particulièrement durant les années 1990 où les taux étaient en moyenne de 3,8 µeq·L[sup –1] ·année[sup –1] . Des reconstitutions paléolimnologiques de l'évolution à long terme du Ca dans six des lacs laissent croire que le déclin général du Ca dans l'eau des lacs s'est poursuivi pendant presque tout le vingtième siècle. Une comparaison des concentrations récentes de Ca dans 16 lacs avec les concentrations estimées d'après les peuplements de diatomées avant l'ère industrielle montre que le déclin de Ca a été important, en moyenne de l'ordre de 74,6 µeq·L[sup –1] ou de 46%. Cette évolution à long terme du Ca peut être le reflet d'une combinaison de facteurs, dont les effets ne peuvent être séparés, en particulier les changements climatiques, les activités de coupe des forêts et le lessivage dû aux précipitations acides. Les déclins du Ca ont des implications biologiques qu'il sera nécessaire de considérer dans la définition d'objectifs appropriés, à mesure que ces lacs se rétablissent de l'acidification.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]