||Wilson, JE, Brown, S, Schreier, H, Scovill, D and Zubel, M. 2008. Arsenic in groundwater wells in Quaternary deposits in the lower Fraser Valley of British Columbia. Canadian Water Resources Journal. 33:397-412.
|Abstract/Description or Keywords
||Elevated arsenic (As) concentrations levels have been found in private groundwater wells in the Lower Fraser Valley of British Columbia (BC) in a regional survey. Forty-three percent of the 98 tested wells showed total As concentrations above the 0.010 mg/L Maximum Acceptable Concentration (MAC) and another 40% were above 0.0003mg/L, a level of concern because of possible long-term lifetime exposure that could result in increased risk of negative health effects. There is clear evidence that As in this region is of natural origin and likely associated with marine and glaciomarine deposits. Arsenic was predominantly found in deep wells, and was positively correlated with variables reflective of marine environments such as B, Na, K, Mo, Cl, PO4, pH and specific conductance. Sixty-seven percent of the samples located in the marine and glaciomarine deposits of the Salish and Capilano formation had As concentrations above the MAC. In contrast, only 28% of all samples in the Fort Langley Formation and 16% of the samples on glaciofluvial sediments of the Vashon and Sumas Drift Formation had As concentrations above the MAC. Arsenic was predominantly found in aquifers that are classified as confined and of low vulnerability, while wells in unconfined glaciofluvial deposits showed little evidence of As.