SUBMERGED TAILINGS STILL POSE RISKS
A typhoon, earthquake, or even unusually heavy rainfall, however, would not only potentially weaken the mine’s structures further. Indeed, environmental experts say anything that can cause a disturbance in the rivers of Mogpog and Boac, as well as in Calancan Bay in Sta. Cruz, could result in the submerged toxic mining wastes there to resurface and make these waters and surrounding areas unsafe.

Magalang quotes the DENR as saying that once the tailings in Boac River are disturbed, oxidation may occur and cause fish kills.

	CHILDREN In Boac, Mogpog, and Sta. Curz have been found to have elevated levels of arsenic and lead in their blood. [photo by Karol Ilagan]

In Mogpog, residents who have to cross the river already complain of chronic skin lesions and the darkening of the skin on their toes. Aside from containing silt from the 1993 dam spill, Mogpog River was also used by Marcopper “as a disposal site for the acidic liquid of the mine tailings," says environmental scientist Emelina Regis in a 2006 paper on the impact of acid mine drainage on the river and the surrounding community.

Calancan Bay, meanwhile, was the recipient of about 200 million tons of mine tailings dumped there by Marcopper between 1975 and 1991. And here in Boac, data from the Placer Dome Technical Services Ltd. (PDTS) — set up to manage the remediation arrangements after Placer Dome Inc. left — say that there are still some 703,228 cubic meters of mine tailings in the Makulapnit and Boac river system, with about 75 percent of this figure in the dredge channel. The rest are scattered throughout the two rivers.

The environment department’s Environmental Management Bureau (EMB) 2006 report on Boac River says that water samples taken from it generally passed the standards set by the DENR for acceptable levels of parameters (cadmium, dissolved copper, dissolved oxygen, and pH).

"The levels of these parameters either improved or had no significant change throughout the years 2000 to 2006,” says the report. But it noted that the concentration of lead in 2006 increased as compared to 2005 results, with two stations failing the DENR standard.

In the meantime, laboratory analysis of the samples taken in Mogpog River in 2006 indicates that “the copper content of the waters…failed to meet the acceptable limits set by the DENR under Class C (fresh) water,” says the EMB. Comparative analysis of the annual results, though, showed that the level of dissolved copper has been decreasing slowly from 2001 to 2006.

CALANCAN BAY MONITORING SUSPENDED
The EMB has continued to monitor both rivers. But since 2005, it has not been getting water samples from Calancan Bay.

Laboratory analysis done by the bureau that year had indicated that the waters of the bay “generally passed the standard set by the DENR for acceptable levels of parameters…(and have) reached and maintained the standard set by the DENR for acceptable limits for Class SB (Coastal and Marine) waters.” This led the EMB to “terminate indefinitely regular water quality monitoring in Calancan Bay to accommodate water quality monitoring in other water bodies within the region.”

Experts like environmental consultant Joel Adriano say that this may not have been a wise move. While Adriano and other experts allow the possibility of contaminated bodies of water to “self-clean,” they argue that it depends on the extent of the pollution.

“If you had polluted it too much, it has its limit, too,” says Dr. Romeo Quijano, a pharmacology and toxicology professor at the University of the Philippines, Manila. “If the source of contamination is still there, then it won’t self-heal.”

It would take a thousand years before the contaminated waterways would “equilibrate,” says Quijano, because heavy metals are highly persistent, especially if it has already been concentrated in the areas.

University of the Philippines National Poison Management and Control Center (UP NPMCC) chief Dr. Lynn Crisanta Panganiban says many of the metals in the mine waste such as arsenic, lead, cadmium, copper, and mercury cannot really be destroyed. She points out, “Iikot lang 'yan sa iba't ibang medium — sa tubig, sa hangin, at maaring pumunta sa tao mula sa isdang kinakain (It will just go around in various media — in the water, air, and eventually, to people from the fish they eat).”

So far, though, no one seems to have come up with suggestions on how to rehabilitate Mogpog River or Calancan Bay. But Marcopper, under intense public pressure following the 1996 Tapian Pit collapse, did at one time propose to haul back the tailings from the Boac riverbed to the pit; Placer Dome, for its part, was pushing for submarine tailings disposal, or pumping the tailings into the sea via an underwater pipe. Neither method, however, apparently appealed to local officials.

In Mogpog, Marcopper’s solution to prevent a repeat of the 1993 flood caused by its mine was to place sacks to raise the banks of the river. In Calancan Bay, all that fisher Paciano Rodelas remembers having been done regarding the mine wastes there was that Sta. Cruz townfolk were asked to grow plants on the mine-waste causeway “to prevent (accumulation of) dust.”