The government has been asked by environmentalists to check on claims that millions of tons of untreated silt have been dumped on an underwater pit on Manila Bay.

Romy Munda, engaged in the coastal clean-up of the bay, said he was disturbed by reports that the multi-billion program for desilting and widening Pasig River led to the dumping of untreated silt on an underwater pit near the mouth of the river.

Munda claimed this is a cause of concern since untreated silt could compromise the quality of water in the bay, which has been classified by the Department of Environment and Natural Resources (DENR) as Class SB, which makes it appropriate for contact recreation, swimming and skin-diving.

DENR recently released the classification of the waters of Manila Bay and raised the total number of classified water bodies nationwide to 632.

Since the Pasig River Rehabilitation Commission (PRRC), an agency under DENR, started the process of restoring the integrity of the waterway in 2008, it had contracted Baggerwerken Decloedt Zn (BDC), a Belgian company, to dredge about 17 kilometers of the river and use phytoremediation and bioremediation to treat the silt for disposal elsewhere.

Phytoremediation and bioremediation measures would eat up 30 percent of the budget for the rehabilitation program and this was purportedly dispensed with by the DENR.

The original project was covered by a 17 million euro supersubsidy from the Belgian government but the cost has since allegedly ballooned to more than P4.5 billion as Manila secured official development assistance from Brussels.

Munda expressed surprise about this move, claiming it could violate existing accords to which the Philippines is a signatory.

In particular, Munda noted that dumping of untreated waste in Manila Bay would violate the provisions of the 1972 London Treaty on Marine Pollution, which bans the disposal of untreated waste on maritime routes.

The accord was ratified by the Philippine government in 1976 and should be in force now, Munda added.