El Niño, polluted Laguna Lake could form a perfect storm

SINCE 2010, the 900-square-kilometer Laguna Lake has been supplying Metro Manila with 300 million liters of potable water every day. The water from the lake, however, is far from pristine, tainted for years by untreated sewage, industrial waste, overfishing and siltation.

The Laguna Lake Development Authority (LLDA) gave the lake a ranking of “C-” for water quality and “F” for fisheries, on a scale of A to F, with F being the worst.

The problem of poor water quality looms even darker following a forecast of a serious El Niño episode that could begin as early as September and last until the first quarter of next year.

The Manila Water and Sewerage Services (MWSS) highlighted the problem during a forum last Saturday. The agency’s officials said blooms of blue-green algae or “lumot” could clog up the filtration system of the two water treatment plants put up by MWSS concessionaire Maynilad at the lake. Blue algae proliferate when temperatures rise and the flow of water slows, conditions brought about by an El Niño event.

If the treatment plants’ filters jam up, Maynilad will once again be forced to schedule water interruptions in large swaths of western Metro Manila.

The LLDA has warned that the algae buildup can also cause fish kills. That’s another serious concern since 80 percent of Metro Manila’s bangus and tilapia supply comes from the lake.

There is also the issue of turbidity, the result of decades of silt buildup in the lake. Siltation has made the lake 2 meters shallower so that a strong gust of wind is enough to stir up sediments in the lake bed, making the water murky.

Turbid water is more difficult to treat, according to Maynilad.

A new form of pollutant could further complicate Laguna Lake’s woes. A study in 2021 revealed that microplastics — minute particles of plastic waste — have contaminated the lake. The microplastics found in the lake are mostly polypropylene fibers, used in making clothing, bags and even medical masks. The microplastics come from the plastic waste dumped into the streams and other waterways that drain into Laguna Lake.

Ruffy Biazon, the mayor of Muntinlupa, the city that shares Laguna Lake with Rizal and Laguna provinces, is calling for stronger action to protect the lake as a water source.

The MWSS said it is bringing in experts from Singapore to take a look at the water treatment in Putatan, Rizal, and determine if it needs an upgrade.

Maynilad said it had installed ultrasonic equipment in its plants to control algae infestation and dredged the area around the intake pipes.

These are, however, disjointed attempts when what is needed is a long-term strategy to rehabilitate Laguna Lake.

There have been numerous plans in the past. One was the Laguna Lake Development and Rehabilitation Project, a P609-billion project proposed by a private consortium and endorsed by the LLDA.

The project covers, among other things, the dredging of 800 million cubic meters of silt and mud.

The project, unfortunately, seems to have vanished into a black hole of bureaucracy.

An extensive paper written in 2005 that lays out a framework for the sustainability of Laguna Lake may be worth looking into. The paper takes a bigger view of the problem, saying that the government’s “legalistic approach” to urbanization failed to contain “the unplanned and unregulated urban expansion as a means of preserving” Laguna Lake’s water quality.

It concluded that while Metro Manila’s urban sprawl “contributed to the deterioration of the lake’s environmental quality, “no framework has been developed to manage” the problem.

Among the paper’s recommendations is that the Metropolitan Manila Development Authority (MMDA) and the LLDA be merged into one agency that will have “both the power to regulate surface waters directly used by Metro Manila and regulate the areas outside of Metro Manila in order to ensure that whatever expansion outside of Metro Manila’s boundaries will not further deteriorate the lake.”

That makes sense today since any impact the coming El Niño will have on Laguna Lake will definitely be felt by Metro Manila.