Department of Conservation to clean up contaminated Alexander River, after Waiuta on the West Coast

The Alexander River site, about 10km from Waiuta (red pointer), is on flood plain. Photo / Google Maps

Fresh from the $2.6 million clean-up of the most contaminated mine site in New Zealand, at Waiuta, the Department of Conservation has applied for consents to also tackle the nearby Alexander River site.

The remote hard-rock goldmine operated between 1924 and 1943 and included a similar ore roasting plant to the Prohibition Mine at Waiuta, near Greymouth.

DoC says there is significant arsenic, mercury and cyanide contamination of the soil.

The Alexander River site, about 10km from Waiuta, is on flood plain, and if the river changes course, toxic material could potentially be washed downstream.

The proposed clean-up will take about 16 weeks. Large tents and a decontamination suite will be set up. The most contaminated soil will be put in barrels and transported to Christchurch.

DoC says it would like to maintain the historic relics on site, especially the Edwards roaster, which was the most intact of its type.

The Waiuta clean-up took from August to November, resulting in the removal of 96 barrels of arsenic-contaminated material.

Lesser contaminated materials were placed in a low lying area on the site and then lined with mullock, the waste rock from the mine excavations.

The $2.6m Waiuta remediation was jointly funded by DoC and the Ministry for the Environment's contaminated sites remediation fund, which will also pay for the work at Alexander River.

Greymouth Star