| Abstract/Description or Keywords |
The Fraser River flows through a vast portion of the southern half of British Columbia, from the Rocky Mountains to the Pacific Ocean. The water quality monitoring site at Hansard, located on a sparsely populated stretch of the Fraser River northeast from Prince George, is the second of five long-term monitoring stations on the Fraser River. Of the remaining four sites, one is upstream, at Red Pass, and the other three are located downstream, at Stoner, Marguerite, and Hope. Water quality indicators measured at this site are compared with those at the nearest upstream site, located at Red Pass. The water in this reach of the river is used for drinking, irrigation, recreation and industry, and sustains significant fish and wildlife resources. The Fraser River from Tete Jaune Cache to Greater Vancouver has been designated a B.C. and Canadian Heritage River. Human activities occurring upstream from this site that could impact water quality include the Yellowhead Highway and the Canadian National Railway, which run alongside the river most of the way from the headwaters to Hansard, forestry, mining, and agricultural activities, as well as the discharge of treated municipal effluent from McBride. The water quality trends identified below have not yet been confirmed by statistical analysis. CONCLUSIONS: • Flows are typical of water bodies in the plateau area of British Columbia, with peaks occurring during the Spring through Summer periods and low flows taking place during the winter. • Several metals had occasional values that exceeded the guidelines for the protection of aquatic life, but also appeared to be correlated with turbidity and were likely not of biological concern. These included aluminum, arsenic, cadmium, chromium, cobalt, copper, iron, silver and zinc. • Total alkalinity has on one occasion been below the guideline that indicates that there is low sensitivity to acidic inputs. • Increasing trends through time were not noted for any variables. • Apparent colour values seem to fluctuate with turbidity and regularly exceeded the drinking water guideline for true colour; however, this is to be expected since true colour is measured on a filtered sample (i.e., turbidity removed). True colour values were lower than apparent colour values, as expected; however, values seem to fluctuate with turbidity and regularly exceeded the drinking water guideline. • Turbidity levels and fecal coliform concentrations would require that drinking water supplies should as a minimum perform partial treatment of the supply. If this level of treatment is applied, Trihalomethane formation should be minimized in thee finished water. • Dissolved oxygen levels were generally acceptable; however, some extremes in temperature above guidelines have been recorded. These generally last for only short periods of time. RECOMMENDATIONS: Monitoring should be continued for the Fraser River at Hansard. It is the control station upstream from the first major population centre (Prince George) and industrial waste discharges (pulp mills) on the Fraser River. Water quality indicators that are important for future monitoring are: • flow, water temperature, specific conductivity, pH, • total dissolved phosphorus, total dissolved nitrogen, periphyton chlorophyll-a, • dissolved oxygen, fecal coliforms, adsorbable organic halides (AOX), chloride, • colour (true and total absorbance), turbidity, hardness, dissolved aluminum, total and dissolved or extractable cobalt, copper, lead, nickel, and zinc. • Low-level cadmium, hexavalent and trivalent chromium, and silver. |
