Two historic gold mines that were claimed to be the most contaminated have now been remediated.
In a joint statement Environment Minister Dr Nick Smith and Conservation Minister Maggie Barry sited the elimination of contamination from the Prohibition mine site at Waiuta and Alexander, also in the Reefton goldfield.
Dr Smith said they were cleaned up in the past 18 months in projects jointly funded by the Department of Conservation (DOC) and the Ministry for the Environment’s contaminated sites remediation fund.
The two projects cost $3.6 million to complete.
He said the Prohibition and Alexander mine sites were acutely toxic. Their levels of arsenic were among the highest recorded anywhere in the world at 400,000 parts per million on land, or 500 times the safe level, and in water at 300 parts per million, or 33,000 times the safe limit for drinking water.
“The Prohibition mine site was contaminated from the operation of a roasting plant from 1935 to 1951, when arsenic bearing ore was roasted to release gold. The sites also have high levels of mercury and cyanide. The mining company has long gone and DOC inherited the site in 1987,” Ms Barry said.
“The Alexander processing plant that produced the high levels of arsenic operated between 1934 and 1936. The mine closed in 1943,” she added.
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