Deloro mine site slated for cleanup

The Deloro gold mine site north of Belleville, Ont., is expected to receive immediate attention under a federal-provincial agreement to clean up toxic dumps in Ontario. Over the next five years, the governments will spend $91.25 million cleaning up “orphan” sites, in lieu of those responsible for the contamination, who either cannot be identified or are unable to pay the required amount.

Environment officials estimate there are 30-50 high-risk orphan sites across Ontario.

In the late 1800s, gold and arsenic were mined at Deloro by dozens of individual interests. From 1907 to 1961, the Deloro Mining and Reduction Co. fed the on-site smelter with silver and cobalt concentrates shipped from mines near Cobalt, Ont. During that time, up to 600 workers were employed at the site.

Although Deloro is usually thought of as a gold mine, in fact a greater quantity of arsenic was produced there over the years, says Chris Ramshaw, a spokesman for Environment Ontario in Kingston. Now, about 10,000 tonnes of calcium arsenite lie in heaps along the Moira River, a source of drinking water for the surrounding communities.

According to Ramshaw, there is some debate about whether the site is crown land, or the property of Ericson Construction, a holding company. Although Ericson took responsibility for property when Deloro was bought in the ’70s, the company has yet to provide any funding for cleanup.

Since 1981, Environment Ontario has been extracting arsenic from the local groundwater at an on-site treatment plant. Ramshaw says the program has been successful in lowering contamination in the Moira River to safe drinking levels during the winter, but summer concentrations average about 0.2 milligrams per litre.

Ramshaw said the government would need about $5-10 million for a thorough cleanup at Deloro. The process would involve covering over the whole site, so that the arsenic-rich heaps would no longer be exposed to the atmosphere.

According to ministry officials in Toronto, no other mine sites have been considered for cleanup funding at this stage.