| Abstract/Description or Keywords |
The St. Mary River watershed is located in the southeast corner of British Columbia. Its headwaters are located in the Purcell Mountains, and the river flows east to join the Kootenay River at Fort Steele (Figure 1). The water quality sampling station is located at Wycliffe, which is 23 km upstream from the Kootenay River and about 9 km downstream from Mark Creek. This assessment is based on up to 31 years of water quality data during 1973-2003. The main human influences on water quality in the St. Mary River watershed were the former Sullivan lead-zinc mine, concentrator and fertilizer plant at Kimberley near Mark Creek, treated sewage from Kimberley, forestry, agriculture, and residential and commercial development. The water quality trends identified below have not been confirmed by statistical analysis. CONCLUSIONS: • There were dramatic improving trends in the following water quality indicators during the 1970’s and 1980’s due to waste abatement for the Cominco operation, and for sewage from the City of Kimberley: alkalinity, ammonia, arsenic, cadmium, hardness, chromium, fecal coliforms, copper, cyanide, fluoride, iron, lead, manganese, nitrogen-ammonia and organic, pH, phosphorus, silicon, sulphate, turbidity, and zinc. • During 1999-2003, there were no further changes in water quality indicators over time, and the following were observed: o Cadmium and zinc often exceeded the aquatic life guidelines. o Copper, lead, and manganese occasionally exceeded aquatic life or drinking water (aesthetic) guidelines during higher flows and turbidity. o Nitrite exceeded the aquatic life guideline twice during low flow in 2000 and monitoring was stopped in 2001. o The water was soft to moderately hard, with a moderate to low sensitivity to acids. o Turbidity levels indicate that partial treatment (e.g., filtration) plus disinfection were needed before drinking water consumption. RECOMMENDATIONS: • Monitoring should continue until water quality guidelines for cadmium and zinc are attained consistently or until it is demonstrated that waste abatement has progressed to the point where there is no detrimental effects on aquatic life in the St. Mary River. • Nitrite monitoring should be re-implemented along with chloride to determine the appropriate aquatic life guideline for nitrite. |
