A proposal to expand a coal mine near Campbell River on Vancouver Island has raised concerns that existing arsenic and sulphate levels already in a local watershed will only get worse.

Quinsam Coal wants to expand its underground mine into an area of higher-sulphur coal.

But a new study of the Quinsam River watershed points to the mine as the source of high arsenic levels in lake sediments, the report's author, UBC professor Dr. William Cullen, told a public meeting in Campbell River on Tuesday night.

The study found arsenic levels in the sediments of nearby Long Lake sediments 30 times higher than provincial guidelines in some places, said Cullen. It also found unnaturally high sulfate levels, both of which the study traced back to the Quinsam coal mine.

Stan Goodrich of the Campbell River Environmental Committee said the company can't be allowed to make the problem worse, when it has failed to address existing arsenic levels.

"If you look at the Canadian Water Network's report, you will see that because the sulphates are still high, that means the arsenic is still coming into the system unabated. And that kind of bothers me," said Goodrich.

Cullen said the company has known about the problem for years and has done little to correct it, and the company's application to expand the mine doesn't propose any improvements.

"At the moment, they can't control what's happening around this particular area, so there's no indication really, that they will be able to do so in the future."

"The whole thing is a bit vague," said Cullen.

The City of Campbell River and the Strathcona Regional District representative have also voiced concerns about the proposed mine expansion.

Officials from the company and the Ministry of Environment and the Ministry of Energy, Mines and Petroleum Resources were invited, but did not send representatives to the meeting.

The Ministry of Energy, Mines and Petroleum Resources is now reviewing the mine's expansion application.

The mine was originally opened in 1986 as an open pit coal mine, but converted to an underground mine in 1994, when remediation efforts at the site were begun.

The Canadian Water Network, which sponsored the study, is a federally-funded program set up to bring science into decision-making processes surrounding water resources.