ASEANO Project Report: Mapping of Sources and Concentration of Plastic Waste in the Imus River Watershed
PUBLICATION DATE:
Tuesday, April 19, 2022
PUBLICATION TYPE:
Reports
STATUS:
Only Available Online
DESCRIPTION:
The sources of plastic wastes and areas of expected high levels of plastic waste generation were mapped in the Imus River Watershed in the Province of Cavite, in the Philippines. Different sources of plastic waste were identified, and used to estimate the magnitude of plastic waste generation. Information on the major sources of plastic waste were obtained from the 10-Year Solid Waste Management Plan of the seven cities and municipalities located within the boundaries of the watershed. Remote sensing technology was used to identify the coordinates of different potential sources. For higher resolution, Google Imagery was used in preparing base maps which were imported and georeferenced in ArcMap. A 7-day waste characterization study in three selected barangays was conducted to determine the average amount of plastic waste generated per household. This data served as inputs for a hotspot analysis in ArcGIS to identify plastic waste generation hotspots within the watershed. The Imus River system traverses seven cities and municipalities that include parts of Tagaytay City, Silang, and Amadeo in the upland areas, a large part of the densely populated and urbanized cities of Dasmariñas and Imus City in the central hilly areas, and portions of the lowland City of Bacoor and the coastal Municipality of Kawit. It has a total drainage area of 11,259.80 hectares. A total of 222 barangay communities were identified within the boundaries of the watershed with a total population of 1,351,057. The major sources of waste in the watershed were primarily households, followed by commercial, institutional, and industrial establishments. The total number of commercial, institutional, and industrial establishments identified was 778, and a total of 54 waste storage facilities were found in the watershed. From the 7-day characterization study in three selected barangay communities, an average of 113.03 kg of plastics was generated daily by the households in Barangay Burol 1, Dasmariñas City; 9.17 kg/day in Barangay Mabolo 1, Bacoor City; and 29.29 kg/day in Barangay Maitim 2nd Central, Tagaytay City. An average of 0.17 Kg/day per household of plastics were generated in the watershed and 0.05 Kg/day per capita. A cluster of high plastic waste generating barangays was identified in Dasmariñas City, where various tributaries of the Imus River converge. This combination is likely to create a significant hotspot for waste leakage. Clusters of low plastic waste generating barangays were identified in parts of Imus, Kawit, and Bacoor. These cold spots should not be ignored, as increasing plastic waste generation could exceed capacity and push them into future leakage hotspots.
RELATED PUBLICATIONS
PEMSEA eBulletin - September 2025
Dear PEMSEA community,
Sail through fresh news and stories this September!
In Jakarta, check out the PNLG Forum 2025, where more than 200 participants from nine countries gathered to showcase innovation and collaboration for coastal action, and read about Guimaras Governor Ma. Lucille Ledesma-Nava taking her oath as PNLG President for 2025–2028.
In Manila, know more about the GEF Regional Project Oversight Training which convened Operational Focal Points from Cambodia, Indonesia, Lao PDR, the Philippines, Thailand, and Viet Nam, in collaboration with PEMSEA and the Philippines’ DENR.
In Busan, look back at the 20th anniversary of the Total Pollutant Loading Management System (TPLMS), joined by representatives from MOF, KMI, academic institutions, civil society groups, and discussions from Ms. Nancy Bermas, Regional Project Manager, GEF/UNDP/ASEAN Integrated River Basin Management (IRBM) Project.
In China, read about PEMSEA Resource Facility Executive Director Aimee Gonzales’ presentation on integrated coastal management at the ICM and Maritime Economy Session, and her participation in the 11th Management Committee meeting of the China–PEMSEA Coastal Management Cooperation Center with officials from the Ministry of Natural Resources.
In the Philippines, know more about the MOF/PEMSEA ODA Project on Reducing Marine Plastics in the East Asian Seas Region Regional Steering Committee’s approval of pilot projects to reduce marine plastics in its six sites, and the 7,000 volunteers mobilized for the International Coastal Cleanup.
Taking the global stage, learn how Orange Omengan, Communications and Knowledge Management Specialist of the IRBM Project, connects science with community realities through compelling visual storytelling with the IRBM Project at the GEF IW:LEARN webinar.
To wrap up the month, explore opportunities to join PEMSEA by visiting the careers section.
PEMSEA eBulletin - August 2025
Dear PEMSEA community,
Catch the wave of news and stories this August!
Explore how PEMSEA is working with LGUS and local stakeholders across the region to advance sustainable coastal and ocean governance. Read about the recent visit to Dipolog City, where PEMSEA Executive Director Aimee Gonzales and Communications Officer Klyra Orbien met with local officials to review progress and discuss the next steps under the MOF/PEMSEA ODA Project on Reducing Marine Plastics in the East Asian Seas.
Learn about how cities are implementing nature-based solutions through the Southeast Asia Conference on Nature-based Solutions in Singapore, where Ms. Gonzales introduced the PEMSEA Network of Local Governments (PNLG) as a vital platform for building resilience in coastal cities.
Discover insights from PEMSEA’s presentation at the FASPS D.R.I.P. Series: Discussions on Results and Innovations of Projects brown bag session, where the team introduced PEMSEA and shared project progress, initiatives, and latest updates.
From Malaysia, see how the Regional Project Management Unit of the Integrated River Basin Management (IRBM) Project advanced work in the Kedah River Basin through high-level discussions, a Water-Energy-Food-Ecosystem (WEFE) Nexus workshop, and a field visit.
Finally, check out PEMSEA’s latest consultancy opportunity on Business Development and Resource Mobilization!
Proceedings of the Seventeenth East Asian Seas Partnership Council Meeting
The 17th East Asian Seas (EAS) Partnership Council (PC) Meeting was held on 22-23 July 2025 at Seda Vertis North, Quezon City in the Philippines (UTC+8).
Onsite participants of the meeting included the EAS PC Chair and Co-Chair; the Intergovernmental Session Chair and Co-Chair; the Technical Session Chair and Co-Chair; the Executive Director of the PEMSEA Resource Facility (PRF); Country partners from Cambodia, China, Indonesia, Japan, Lao PDR, Philippines, RO Korea, Timor Leste, and Vietnam; Non-Country Partners from the Conservation International Philippines (CI PH), Ipieca GISEA, Korea Institute for Ocean Science and Technology (KIOST), Korea Maritime Institute (KMI), Korea Marine Environment Management Corporation (KOEM), and the National Marine Hazard Mitigation Service (NMHMS).
Online participants included country partners from Singapore and RO Korea; Non-Country Partners from the ASEAN Center for Biodiversity (ACB), International Environmental Management of Enclosed Coastal Seas Center (EMECS), Korea Maritime Institute, Oil Spill Response Limited (OSRL), and the Plymouth Marine Laboratory (PML). The meeting was also attended by online observers from UNDP Philippines, Tokai University, and the Department of Environment and Natural Resources (DENR).
Regional Baseline Assessment on Marine Plastics in the East Asian Seas Region (Philippines and Timor-Leste)
As part of Component 1 of the MOF/PEMSEA ODA project on the Reducing Marine Plastics in East Asian Seas Region, a Plastic Analysis and Characterization Study (PACS) was conducted to provide essential data to guide project decisions and establish 10-year marine plastic management strategies and action plans, which will be developed, adopted, and implemented by local governments and stakeholders. This regional baseline assessment on marine plastics includes the conduct of PACS and Knowledge, Attitude, and Practice (KAP) Survey, specifically focusing on key coastal areas in the six cities and municipalities in the Philippines: Bulan, Calbayog, Daanbantayan, Dipolog, Puerto Princesa, and Tandag; and four municipalities in Timor-Leste: Atauro, Dili, Liquiçá, and Manatuto. These components are designed to understand the specific dynamics of plastic waste generation and local community behaviors towards waste management.
The regional synthesis identified persistent challenges across the plastic waste value chain, including high plastic waste generation, weak segregation, limited collection coverage, low recovery performance, inadequate disposal systems, and continued plastic leakage. Addressing these issues requires targeted interventions across all stages of the solid waste management system. Key recommendations focus on reducing single-use plastics through local policy and behavior change, improving segregation by providing bins and strengthening implementation, and expanding collection through additional vehicles and better route planning. Recovery must be enhanced by upgrading facilities and linking communities to recycling markets, while safe disposal options should be developed or improved to reduce open dumping and burning.
Baseline Assessment Report on Marine Plastics in the Six ODA Project Sites in the Philippines
This Baseline Assessment Report of MOF/PEMSEA ODA project on the Reducing Marine Plastics in East Asian Seas Region includes both the Plastic Analysis and Characterization Study (PACS) and a Knowledge, Attitude, and Practice (KAP) Survey, specifically targeting key coastal areas in six Philippine sites: the municipalities of Bulan and Daanbantayan, and the cities of Calbayog, Dipolog, Puerto Princesa, and Tandag. These assessments aim to uncover the specific dynamics of plastic waste generation and local community behaviors toward waste management, supporting the development of data-driven interventions to address marine plastic pollution effectively.
The findings of the synthesized national baseline assessment provide valuable insights that can assist local government units, national government agencies, and relevant stakeholders in developing targeted policies and interventions. These strategies are aimed at improving solid waste management practices and reducing marine plastic pollution in coastal cities and municipalities.