The Muntinlupa City government, Laguna Lake Development Authority (LLDA), and Maynilad Water Services will enter into an agreement to address the problem of algal bloom in Laguna Lake, which has hampered water service in Muntinlupa and resulted in fish kill.
The Muntinlupa City Council has given the go-signal for Mayor Jaime Fresnedi to enter into a memorandum of understanding for the use of solar-powered paddle wheels to implement the project “Introduction of nutrient-limiting mechanism to prevent algal bloom in Laguna Lake.”
Recently, Maynilad implemented water service interruptions in Muntinlupa and other areas along the supply chain of its Putatan Water Treatment Plant in Barangay Putatan, Muntinlupa.
The treatment plant sources raw water from Laguna Lake, processes it and supplies it to Maynilad customers.
Maynilad said algal bloom in Laguna Lake since May 31 has forced it to implement water service interruptions. It said the algal bloom affects the raw water that enters its plant.
Under a memorandum of understanding between the Muntinlupa LGU, LLDA, Maynilad and Barangay Putatan, solar-powered paddle wheels will be used to control algal bloom.
According to an advisory last year on, the LLDA said, “The observed formation of algal bloom in the lake could have been triggered by the combination of various factors such as the prolonged hot weather and calm lake condition this summer followed by the heavy influx of nutrients into the lake particularly nitrate and phosphate from the tributaries after the rainy season started this June.”
“In this regard, intense algal bloom may occur in sheltered or cove areas of the lake and that the places where the algal bloom usually accumulates will depend on the prevailing wind direction. The problem associated with algal bloom is that it uses much of the oxygen in the water column at nighttime for their respiration which could lead to shortage of oxygen available for the fish stocks in aquaculture structures, particularly in fishpens and fishcages. Fishkills or death of the fish stocks may happen if they failed to recover from stress due to insufficient supply of oxygen in the water,” it added.
It said, “Massive algal bloom collapse or die-off also usually happens when there will be a sudden drop in the water temperature of the lake from very high after a heavy rainfall or the supply of nutrients becomes exhausted. This can also result to oxygen depletion in the water and may lead to fishkills due to massive decomposition of the dead algae.”
The MOU noted that “the decaying algae exudes nauseating odor and causes oxygen depletion and turbidity in the water thereby resulting to fish kill and contamination of drinking water facilities.”
Under the agreement, Maynilad will donate paddle wheels and water quality analyzer to the Muntinlupa City government, which will be the implementing agency of the project.