Maynilad Water Services, Inc., the water concessionaire for Metro Manila's West Zone, has set aside roughly P10 billion to rehabilitate and modernize its La Mesa water treatment facilities in Quezon City, a move intended to shore up water supply reliability as El Niño brings the threat of drier conditions. El Niño, a recurring climate pattern that typically brings below-normal rainfall to the Philippines, can reduce inflows into the Angat-Ipo Dam system, the raw water source feeding these facilities.

Speaking at a press briefing on Tuesday, Maynilad Vice-President and Head of Water Supply Operations Ronaldo C. Padua said the work is aimed at expanding the system's storage capacity. "We are preparing our system so that we can increase the (capacity) of our reservoirs. It is important (to upgrade our system) to increase the availability of water or the volume of water available from our sources," he said.

According to the company, the investment covers improvements to water treatment processes, recovery and augmentation systems, and additional raw water storage. At full capacity, the combined recovery and augmentation systems are designed to deliver between 125 million and 179 million liters of water per day (MLD).

Raw water storage at La Mesa is also being expanded to 200 million liters by December, up from the currently reported capacity of 133 million liters. The additional storage is meant to serve as a buffer during periods of reduced water inflows from the Angat-Ipo Dam system, which supplies raw water to the treatment facilities. That buffer is where El Niño becomes a practical concern: when inflows tighten, stored raw water gives the plant room to keep treating and delivering water. The December target for reaching the 200-million-liter capacity is a milestone worth tracking, since it marks when the added cushion is expected to be in place.

A key element of the project involves converting former sludge lagoons into reservoirs for untreated water. Maynilad said Lagoons 3 and 4 together provide a combined storage capacity of about 133 million liters, equivalent to roughly two-thirds of the planned total.

The company is likewise upgrading La Mesa Water Treatment Plant 1 to raise its capability to handle raw water turbidity from about 300 nephelometric turbidity units (NTU) to a peak design level of 2,000 NTU. Turbidity measures the cloudiness of water caused by suspended particles. The higher design ceiling is intended to allow the treatment plant to operate under a wider range of raw water conditions, particularly when sediment levels increase, giving operators more room to keep processing water as source conditions shift.

The rehabilitation program also covers improvements to sedimentation, filtration, sludge management, and monitoring and control systems, along with the replacement of aging equipment. "Maynilad's continuing rehabilitation and process improvements at La Mesa include enhancements to sedimentation, filtration, sludge management, monitoring and control systems, as well as the replacement of aging equipment and other facility improvements," the company said in a separate statement.

Maynilad provides water and wastewater services in the West Zone of the Greater Manila Area, covering portions of 11 Metro Manila cities and parts of Cavite province. That service footprint is why the condition of the La Mesa facilities matters well beyond Quezon City: the upgrades determine how reliably raw water drawn from the Angat-Ipo system can be treated and delivered to homes and businesses across the West Zone while drier conditions put pressure on source inflows.

Metro Pacific Investments Corp., which holds a majority stake in Maynilad, is one of three Philippine units of Hong Kong-based First Pacific Co. Ltd., alongside Philex Mining Corp. and PLDT Inc. Hastings Holdings, Inc., a unit of PLDT Beneficial Trust Fund subsidiary MediaQuest Holdings, Inc., has an interest in BusinessWorld through the Philippine Star Group, which it controls. — Ashley Erika O. Jose