West Zone concessionaire Maynilad Water Services Inc. (Maynilad) is looking to purify used water to make it potable, similar to what is now being done in Singapore, South Africa, Namibia, and the United States.
“Water is a scarce resource. Given the growing population’s increasing demand for water plus the strain on existing sources due to climate change, we should consider using previously untapped sources—including used water—to augment supply. There are now reliable and effective treatment technologies that make it a viable option,” said Maynilad President and CEO Ramoncito S. Fernandez.
Maynilad is planning to utilize some of its new Modular Treatment Plants (ModTP) for this purpose—instead of purifying raw water drawn directly from rivers, it will purify the already-treated used water that are just discharged to rivers by its Sewage Treatment Plants (STP).
“The treated used water discharged by STPs is actually a more reliable water source than raw river water because it is climate independent; the quality is controlled and less variable,” said Maynilad Quality, Sustainability and Resiliency head Roel S. Espiritu. “If we use the river directly as source, trash and other pollutants thrown into it by surrounding communities could drastically change the river water’s quality. This could affect the volume output of a ModTP, which has to adjust its treatment parameters with sudden shifts in the raw water quality.”
Maynilad treats raw water from Laguna Lake in a similar way, as it uses a sewage treatment method for initial purification of the lake water before it passes through several more treatment processes for full conversion to drinking water. The company has been tapping Laguna Lake as alternative raw water source since 2010, which enabled it to reduce over-reliance on Angat Dam and serve customers in the south.
The ModTPs of Maynilad use treatment technology from Israel—a known global leader in water innovation—featuring a multi-stage process that includes Pressurized Media Filtration, Ultrafiltration, Reverse Osmosis, and Chlorine Disinfection to convert used water to drinking water.
“By including used water to our supply source options, we have enhanced capability to generate more water whenever existing supplies run short,” added Fernandez.
Maynilad is working with local government units, the Department of Health and other government agencies to ensure that the used water treated by Maynilad’s ModTP is potable. The company is also conducting a series of market research activities to establish social acceptance among consumers of water reuse.