Surface water quality in Manitoba with respect to six chemical parameters, water body and sediment type and land use

Surface waters at 425 sites in Manitoba were analyzed for total dissolved solids, nitrate-nitrogen, dissolved organic matter, cadmium, lead and copper. Regional differences in chemical parameters were found for various areas of the province and for some bottom sediment types. Sites were classified according to predominant type of land use: minimal, cropland, livestock, mining, recreation, forest logging, hydroelectric development and urban effluent. The highest mean values of total dissolved solids, cadmium and copper were associated with mining, although the highest absolute values for copper were found in cottage and recreational areas due to the use of copper sulphate to control algal blooms. Urban effluents and agriculture significantly elevated total dissolved solids and nitrate. Elevated dissolved organic matter was most associated with land clearing and urban effluents. The relative significance of the various human activities differed with geographical region. Streams were the most vulnerable to contamination, particularly on the Precambrian Shield. Water quality problems exist in some areas in the province, and management must take into account the regional characteristics of surface waters, as well as address the varying nature and intensity of contamination generated by human land uses.

Keywords:

• mining
• sewage
• cottages
• land clearing
• agriculture
• nutrients

Acknowledgments

I would like to thank Bryan Martel for assistance with the field sampling, and the University of Winnipeg and Environment Canada for funding. I would also like to thank anonymous reviewers who contributed valuable suggestions for the manuscript.