MANILA — The Department of Natural Resources (DENR) on Tuesday hoped the oil spill leakage could be fully controlled "within the month," just as it is still undertaking impact analysis on the spill's ecological damage.

Environment Secretary Toni Yulo-Loyzaga said it was "very difficult to say" how long the final leaks could be finally stopped but this is being processed.

"What we would like to say is at this point let’s take a look — hopefully within the month or so the leakage will probably be contained definitely and we will actually be able to say what kind of damage has been incurred in the ecosystems that are submerged in the water," Loyzaga told Palace reporters.

"When it comes to the waters on the shoreline, we will continuously test for the presence of any kind of contaminants and we will be there I think much longer than other agencies because the ecosystem impacts are actually long-term," she added.

The Philippine Coast Guard earlier said that the oil spill leakage from MT Princess Empress has already been "significantly controlled."

There is still one remaining pressure valve, however, producing a "slow intermittent release of oil" and it was not capped "due to obstructions that may compromise the ROV operations," said the PCG.

• Oil spill leaves P130-M damage in Pola, Oriental Mindoro, says mayor

Meanwhile, the DENR chief noted her agency is still working on the impact analysis to find out what ecosystems and areas are affected by the oil spill.

DENR's personnel though must go there to physically assess the damage. They are also seeking the help of experts, such as the US Nationwide Operational Assessment of Hazards, United States Agency for International Development, and other non-profit organizations, for the valuation.

"The DENR has the capacity to go down there- we have the divers, we have an [remotely operated vehicle] and we need to actually have physical confirmation of the range of the actual impact in order for us to say makaka-recover ba, gaano ba katagal," she said.

Pola, Oriental Mindoro has so far sustained around P130 million in damage from the oil spill that spread across the province's waters, according to an official.

Some 4,800 fisherfolk and their families have been affected by the oil spill, a number of whom experienced respiratory illnesses aside from losing their livelihood.

Video from PTV