The sequence batch reactor at the Ilugin Sewage Treatment Plant in Pasig City. As of 2021, the East Zone has a total of 41 Sewage Treatment Plants (STPs), with a total wastewater treatment capacity of 410 million liters per day (MLD).
MANILA, Philippines — After 25 years of operations, Manila Water Company, Inc. has made huge headway in growing its wastewater services in the East Zone concession area. From a single sewage treatment plant in 1997, Manila Water now operates 41 treatment facilities, increasing the company’s wastewater treatment capacity by 1,025%, from 40 million liters per day (MLD) at the start of operations to 410 MLD at present.
For the years left in its franchise, the water company will be building 13 additional STPs as it continues to fulfill its mandate of providing sewerage and sanitation services to help improve the conditions of the water environment in the metropolis and thereby safeguard public health, in addition to providing clean and potable water to the millions of customers in the concession area.
“Covering almost all of our customers’ needs for proper sewerage and sanitation is half of our mandate, equally important to our goal of providing them clean and potable water,” said Manila Water Operations Group Director for East Zone Arnold Jether A. Mortera.
Manila Water targets to have a total of 53 UW facilities with 1,322 (MLD) treatment capacity which will cover 99% of its concession area.
“This translates to a total of 885 kilometers of sewer network to serve 7.4 million population in the East Zone, our service area,” Mortera added.
Rapid and effective sewer coverage expansion since 1997
A year after it managed the East Zone concession, Manila Water began planning the wastewater management system, which took three years before construction of STPs that started in 2000. By 2005, it had completed and started the operations of additional 29 STPs, doubling its treatment capacity from 40 MLD to 80 MLD. This involved upgrading of the existing communal septic tanks to the separate system using a decentralized approach that used pre-existing sewer network. These are in areas in Makati, Quezon City, Taguig, Pasig, Cainta, and Mandaluyong.
In 2008, Manila Water started operations of 2 septage treatment plants, which treated wastewater coming from sources that had individual septic tanks through desludging trucks. The North Septage Treatment Plant located in San Mateo served the north area of eastern Metro Manila with a 0.586 MLD capacity. The South Septage Treatment Plant in FTI Taguig served the south area of eastern Metro Manila with a 0.813 MLD capacity. Together they increased the total treatment capacity to 83 MLD. Desludging of these individual septic tanks was done every 5 years.
A year later, the water company started operations of combined sewer-drainage treatment plants, providing an incremental capacity of 52 MLD by 2014 bringing the total capacity to 135 MLD. These were the Capitolyo STP in 2009, Olandes STP in 2010, Poblacion STP in 2012, and Pinagsama STP in 2014. Operations of large facilities started in 2016 with the Marikina North STP and Taguig North STP, with a combined capacity of 175 MLD. By 2017, 40 STPs were operational, with a total capacity of 310 MLD that served more than 1.6 million users. This rapid and effective sewer coverage expansion resulted in an immediate environmental impact in the areas.
Wastewater management strategies
Wastewater is a general term that includes all “used water” discharged by households and commercial and industrial establishments.
The wastewater management of Manila Water includes the collection of sewage and septage from households and establishments to conveyance, full treatment, and safe disposal of by-products.
In recent years, Manila Water undertook a major project to ensure compliance to DENR Administrative Order (DAO) 2016-08 that included new parameters in biological nutrient removal (BNR) on nitrogen and phosphorus. This entailed the diversion of flows from 11 smaller treatment plants to larger facilities and operational adjustment to 27 others. Last year, the DAO was amended to DAO 2021-19, raising the standards for 6 parameters including NH3-N and P. By June 2021, all of MANILA WATER’s 41 STPs have complied with this amended order, which resulted in 4,708 tons of nutrients per year.
To achieve efficiency, the water company strategically employs an Operations Central Monitoring System to oversee all activities. It also implements technologies in wastewater management, including among many, the use of Geotube® dewatering technology made of specially engineered textile that efficiently drains off liquid from wet solid materials into clear effluent water.
A community endeavor
Building the wastewater management system takes a whole community, according to Mortera. “To continue building wastewater infrastructure and improving the sewer network until all our customers have access to sewerage services is a community endeavor,” Mortera said.
As challenges arise, the water company works with stakeholders in tackling the impact that result from the construction projects. For example, since the work is mostly done underground, the projects impact traffic flow and road use. The water concessionaire also deals with land availability since building treatment facilities require big land areas.
“To our customers, they can ask how they can avail of Manila Water’s sewage treatment services by connecting to our sewer lines. The more households connecting to these sewer lines, the better our work with achieving our goal,” Mortera said. “They can also avail of Manila Water’s septic tank cleaning services at no extra cost.”
To encourage customers to cooperate towards achieving these goals, the company initiated ‘Toka Toka’, the first and only advocacy in the Philippines focused on wastewater management. Now running for 10 years, Toka Toka encourages everyone to take part through (four) 4 ownable acts: (1) connecting to sewer lines; (2) proper solid waste disposal; (3) availing of Manila Water’s desludging services; and (4) supporting the campaign by sharing the advocacy with the community. Toka Toka now counts hundreds of partners in local government units and national government agencies who help spread the advocacy through their respective offices and communities.
Notwithstanding the challenges, Manila Water is committed to complete the wastewater management system to 99% coverage while relying heavily on the cooperation of the communities it serves.