Bertrand Creek is a small transboundary watershed with mixed land use that provides a good case study to compare the impacts of urban and agricultural activities on water resources. Located in southeastern Langley, it encompasses the city of Aldergrove and an agricultural area that extends from south of Aldergrove to the Canada - US international border. The main goal of this study was to determine land use impacts on water quality. Water samples were analyzed for nutrients and dissolved

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... s and results were linked to land use through a GIS. Streambed sediments were analyzed for trace metals and bioavailability of metals was measured along Bertrand Creek using the diffusive gradients in thin films (DGT) technique. Land use didn't seem to be correlated to groundwater quality but results indicated that nitrate contamination in the Abbotsford aquifer is a concern. Well depth appeared to have a significant influence in the quality of groundwater and only wells <15 m deep exceeded the drinking water quality guidelines for NO₃ - N. Surface water analysis indicated high concentrations of nitrate and phosphorus, especially on Howes Creek. Correlation with land use data showed that high concentrations of manganese in surface water and concentrations of copper, lead and zinc in sediments were positively correlated to the extent of impervious surfaces. Nitrate - N concentrations were influenced by agricultural activities particularly during the wet season. It is therefore important that stormwater and agricultural best management practices be exercised, including the increase of riparian buffer areas, improved manure management and storage techniques and the construction of stormwater detention ponds, particularly at sites that receive direct runoff from heavily used roads. Despite the importance of the streams in this watershed to aquatic life there appears to be a significant lack of water quality studies and monitoring. The results of the present study warrant further research in the water [...]