Toxic chemicals pouring from mines, says expert

By ANNE BESTON environment reporter

The Government should be doing more to protect the countryside against toxic contamination from mines, according to an Auckland scientist.

Dr Richard Anstiss has completed an investigation into contamination from a coalmine on the West Coast.

He said he was not surprised by the levels of toxic chemicals found in streams near the Stockton coalmine, owned and operated by state-owned Solid Energy, but believed the amount of pollution from coal and gold mining was higher than the Government wanted to acknowledge.

"I think the amount coming out of those mines is more than what is acceptable," he said.

Dr Anstiss is an environmental geo-chemist who teaches at the Auckland University of Technology. He is director of the Trace Element Research Group which investigates contaminated sites.

He said there was not enough independent research into contamination from mines.

His investigation at Stockton mine was based on data collected in 1996.

It has been peer-reviewed and will be published in a Royal Society of New Zealand journal this month.

A study of streams flowing from the Stockton mine, 35km northeast of Westport, found high levels of toxic chemicals.

Of 18 water sampling sites, 17 showed levels of chemical contamination well over Ministry of Health drinking water standards.

The peak level for nickel in some streams was up to 36.5 times the maximum allowable for drinking water.

Arsenic peaks were 4.2 times the ministry standard and lead levels were 3.4 times over the standard.

The average concentration of nickel in streams was eight times over the ministry's standard.

Dr Anstiss said the chemicals had a range of toxic effects and tended to accumulate in the environment and the animal and plant life of the local regions.

That meant the chemicals could reach humans through consumption of water or fish.

But Solid Energy technical manager Mark Pizey said streams which take run-off from the mining operations on the Stockton plateau were not used for drinking water or irrigation.

The streams had naturally-raised trace element concentrations due to the geology of the area as well as historic and current mining activities.

Since Dr Anstiss and his team carried out the field work in 1996, the company had made "significant advances" in the monitoring and management of water discharged from the Stockton plateau, Mr Pizey said.

But Dr Anstiss is sceptical. "I don't believe the situation would have changed much," he said.

He also believes that Stockton mine is just one of dozens of both coal and gold mines in New Zealand which are "hosing out" toxic material.

"Obviously you can't have a mining industry and have no pollution whatsoever - but it's a question of whether you have a little or whether you have heaps."

That was a political decision, not a scientific one, he said.

Chronic, longer-term localised contamination problems such as those found near the Stockton mine had to be given priority even if that meant less commercially oriented solutions.

Dr Anstiss said transparent monitoring systems had to be introduced rather than the "piecemeal" approach carried out now in which local and regional governments were responsible for regulating mining in their areas.

Small councils lacked resources and expertise to monitor complex pollution issues and often only the mining company had the data on how much leakage there was from mines.

Dr Anstiss said that in small communities, companies had a lot of influence.

"Responsibility for mining has devolved to local councils but that has led to a lack of transparency."

He said scientists were willing to help companies by advising on how chemicals could be removed before they entered the environment.