Another contaminated site in the West Kootenay region has been identified and is being cleaned up.
Once a prolific producer of silver and lead in the 1930s, the Howard Mine north of Salmo left behind exposed quantities of mine waste, eroding into the Salmo River and contaminating the groundwater.
But according to the Crown Contaminated Sites Program 2012 biennial report, the contamination from the mine seven kilometres north of Salmo has been identified, removed and is now being remediated.
Inactive since 1938, the mine was located in a “challenging geographic location,” with an ore-processing mill built at the meeting point of Salmo River and Porcupine Creek.
“Key concerns here (were) exposed mine tailings, ongoing erosion of the tailings into the Salmo River and groundwater contamination,” read the provincial report.
Site investigations now support the development of a remediation plan to protect human health and the environment.
In 2009 a site investigation showed acid generating mine tailings containing high concentrations of arsenic, cadmium, lead and zinc existed at the site.
After mining operations ceased almost 74 years ago, most of tailings were removed by the flow of the river. However, it was determined about 8,000 tonnes of tailings remained within the floodplain and posed a risk for further erosion when the investigation was done four years ago.
One year later in 2010 another site investigation with a human health risk assessment were completed, finding that tailings in the floodplain and in areas around the mill footings had concentrations of metals that presented a potential risk.
“Metals from the tailings (were) also leaching into the groundwater,” the report stated.
The area was fenced off until work began in the fall of 2011 to remove the tailings, with additional groundwater work conducted to complete the remedial planning.
The physical remediation is expected to begin once the design-build plan is ready, the report predicted.
The goal of the Crown Contaminated Sites Program is protecting human health and the environment by returning land to a clean and usable state. A total of 82 sites have been investigated since the program began in 2003, with five new candidate sites investigated in 2011.
A scientific risk ranking method is used to help make decisions and is based on the condition of the site. Some sites have been contaminated to the extent that human health and the environment are endangered and these receive priority remediation. Others do not pose a significant risk and therefore do not need immediate attention.
In 2011/2012, site investigation and remediation province-wide cost $4 million.