MANILA --The Department of Environment and Natural Resources (DENR) is open to considering technologies for cleaning up Manila Bay and its tributaries.

Inventors and other parties with technologies may propose these to DENR for possible use in the cleanup, said DENR Undersecretary Jonas Leones.

“Work involved is so big,” he said, highlighting importance of technologies and help of all sectors in cleaning up effectively in the shortest time possible.

Among the project's priorities is addressing flow of solid waste and untreated effluents into Manila Bay and its tributaries to reduce level of coliform bacteria in these water bodies.

Leones said the work will also involve dredging activities to remove silt and trash below the surface of water there.

"The entire Manila Bay will be dredged," he said.

He also said there'll be dredging of all Manila Bay tributaries.

"We must dredge because even if effluents flowing into Manila Bay pass treatment, this water body will still be polluted due to silt and trash underneath," he noted.

Accumulation of silt and trash over the years already reduced water-carrying capacity, affected water flow and worsened water pollution in Tullahan River which is among Manila Bay's tributaries, Leones noted.

He said divers who checked conditions in Manila Bay's middle portion last week reported a 4.0 meter-high silt and trash beneath surface of water there.

"To really clean up Manila Bay, silt and trash must be removed and disposed properly," he said.

Cleaning up, relocating Manila Bay's informal settlers and educating the public on solid waste management are major activities for rehabilitating this water body.

According to experts, bioremediation is an eco-friendly and cost-effective natural technology which uses micro-organismal metabolism to remove contaminants in water.

Dredging technologies help improve removal of silt and trash in water bodies, they noted.

In 2008, the SC ordered 13 agencies to clean up, rehabilitate and preserve Manila Bay.

Those agencies are the environment, agriculture, public works, interior, education, health and budget departments, Metropolitan Waterworks and Sewerage System, Local Water Utilities Administration, Metropolitan Manila Development Authority, Philippine Coast Guard, Philippine National Police-Maritime Group and Philippine Ports Authority. (PNA)