Tb. Arie Rukmantara, Jakarta – The environmental damage caused by PT Freeport Indonesia's Grasberg mine in Papua province is much worse than earlier reported by the government, an environment watchdog says.

The Indonesian Forum for Environment (Walhi) alleged Wednesday that the subsidiary of the US based Freeport McMoran mining company had committed more violations of national environmental regulations than the government was holding to account for.

"Our study found the company's (disposal of its) total suspended solids also violated the country's regulations," Walhi deputy director Farah Sofa said.

The government in March announced Freeport violated Indonesian environmental regulations over its management of mine acid drainage and for failing to get a license to dispose of its tailings into a river.

It also said Freeport's power plant, managed by PT Puncak Jaya Power, failed to meet air pollution standards.

Walhi's report said the joint mine operation by Freeport and Australian miner Rio Tinto had violated a 2001 government regulation on water quality management and pollution control by not preventing dissolved copper from polluting the Aijkwa River, where Freeport deposited its tailings.

"The lower Aijkwa River (was found to) contain 28 to 42 micrograms a liter of dissolved copper. That is twice as high as the maximum limit the government set at 20 micrograms a liter," the report says.

The report is based on a year's study of unreleased documents about the mine Walhi obtained from an environmental auditing company, geologists and environmentalists.

The report says the river estuary and sea waters are also being contaminated by dissolved copper to levels that exceed tolerable standards.

Walhi's energy and mining campaign manager, Torry Kuswardono, said Freeport's total tailings were estimated to amount to more than a billion tons. Piled up along the 230,000-square kilometer modified Aijkwa Deposition Area, they were endangering many species living in the area, he said.

"Freeport's tailings have made some 35 percent of fish and shellfish populations in the river estuary vanish. At present, about 30 percent of the species living there have been contaminated and are threatened with extinction," he said.

Torry said Walhi publicized the report to convey "a message" to Rio Tinto stockholders, who are expected to attend the company's annual shareholders meeting in Melbourne on Thursday. "Hopefully, they will question Rio Tinto's policies," Torry said.

Rio Tinto owns 40 percent of the Grasberg operation.

"We would also like to give additional data to members of the House of Representatives working committee on Freeport, who will visit the Grasberg mine Thursday," Torry said.

Walhi demanded the government take immediate legal action against Freeport, or at least seriously review the company's operations.

"We are no longer talking about closing down the operation. Should the government refuse to take legal action, we urge them to establish an independent panel to formulate a future plan for the Freeport mine, which is more environmentally friendly," Torry said.

"The panel's duty should also include calculating the compensation Freeport must pay for destroying the environment," he said.

Freeport spokesman Siddharta Mursjid said he could not comment on Walhi's report because he had not yet seen it. He said Freeport's operations were in compliance with the government's 1997 environmental impact analysis (AMDAL).

"All I can say is that we are aware that every action carries a risk, but the risk of our operation was estimated in an AMDAL. And we have always carried out our operations according to the AMDAL," he told The Jakarta Post.