Two structures built by Marcopper have caused untold suffering to the people of Marinduque for more than two decades - The Maguilaguila Siltation Dam that burst in 1993 and has forever polluted the Mogpog River, and the Tapian Pit, a 130-ha wide and 320-m deep hole. In 1996, a leak in its drainage tunnel caused a fracture that discharged 1.4 million cubic meters of tailings along 27 kms of the Boac River and coastal areas.
The Maguilaguila Siltation Dam was re-engineered after the disaster with the construction of an overflow, just a channel dug through the top of the dam to allow water to escape when the water level behind the dam is elevated. At present the dam's catchment reservoir is already heavily silted and awaits another catastrophic collapse.
Two days ago, photos taken by Army CAFGU operatives of the little known Makulapnit Dam Tunnel of Marcopper, also called Makulapnit Diversion Tunnel, has alarmed local netizens. The pictures published on Facebook show water gushing out in rapid speed from multiple fractures inside the tunnel.
The matter has been reported by Boac's planning officer, Luna Manrique to the Department of Environment and Natural Resources (DENR).
A team from the DENR composed of representatives from the Mines and Geosciences Bureau (MGB), Environmental Management Bureau (EMB) and DENR-PENRO is set to arrive in Marinduque on Monday, Jan. 23, to inspect the site and assess the situation.
Location of the Makulapnit Dam Tunnel also known as Makulapnit Diversion Tunnel. Tunnel leading to where?
Progressive erosion had significantly altered the steep slope of the Maguilaguila waste dam causing unchecked siltation along its stream channels since 1993. This has aggravated the siltation problem in the lowlands of Mogpog resulting in flash floods.
The Maguilaguila siltation dam's catchment reservoir is already heavily silted and is contributing to its imminent collapse.
Is Marcopper's Makulapnit Dam ready to burst?
Leaks found in abandoned Marcopper Dam
Bagong banta: Pagguho ng lupa sa gitnang bahagi ng Maguila-guila Siltation Dam o 'Subsidence'