VANCOUVER/WARSAW - Polish miner KGHM KGH.WA said on Friday it was considering its next step after British Columbia said it would not issue an environmental certificate for its Ajax copper and gold mine in the province's interior.

The proposed mine aims to produce 109 million pounds of copper a year and 99,000 ounces of gold. It is located some 10 kilometres (6.2 miles) from the city of Kamloops, in central British Columbia, and is on the traditional territories of four Indigenous communities.

British Columbia said on Thursday the adverse effects of the project would outweigh any benefit. The province's decision follows a seven-year joint review by provincial and federal regulators, which found that the project would have 53 residual and cumulative adverse effects, 21 of which were considered of moderate to high magnitude.

"KGHM Ajax (...) will consider taking further steps, which could include using an appeal measure," the Polish miner said in a statement released on Friday.

Canada's environment minister Catherine McKenna separately recommended against the project on Thursday, saying it was likely to cause "significant adverse environmental effects and cumulative effects to Indigenous heritage."

A final federal decision will come down to Prime Minister Justin Trudeau's cabinet. No timeline was given for that decision.

In its statement, British Columbia said because the 1,700-hectare open pit mine would be so close to the city, and in particular an elementary school, it would present an "unacceptable risk."

It also noted that the area was of "high importance" to local First Nation groups and its development would have a significant effect on their heritage and right to use the land for traditional purposes.

KGHM has said the mine would create 1,800 construction jobs and 500 full-time positions, along with significant tax benefits for the city and province.

It entered into a joint venture to develop the project in 2010 with Abacus Mining AME.V which owned the rights and in 2012 increased its stake in the Ajax project to 80 per cent from 51 per cent.

Shares in KGHM fell by 0.05 per cent at 6:27 a.m. ET.