MANILA - Former Environment secretary Gina Lopez said Monday open-pit mining would be a "financial liability" to the government as an inter-agency council studied the lifting of a ban she put in place against the practice.

Lopez, whose appointment to the environment post was rejected by lawmakers, said when a company halts operations, its open pit will be filled with water, which will later turn toxic.

"We’d have to detox that open pit water forever. Who is going to do that? The government? Each open pit is a financial liability to government for life because no matter if the mining company commits to take care of that open pit, will they take care of it forever?," she told reporters.

"It is a financial liability for life, and is it right that our taxpayers money, meant for our people, for food, for education, for our people, be used to address open pit? But if the mining company goes, what choice do we have?" she added.

Before she stepped down last May, Lopez also ordered several mines shut or suspended and threatened to cancel dozen other contracts.

Lopez said mining sometimes works to the "detriment" of host communities.

"The existence of open pits destroy the economic potential of the place. It destroys it. Once you put it there, what can you do there? Can you invest there?" she said.

"The existence of open pits violates the constitutional rights of our people to a clean and healthy environment…For whatever law or whatever legal thing they say, it is a violation of our constitutional rights," she added.