01 · The problem
What is happening
A 2021 study in Science Advances estimated that a large share of global riverine plastic emissions come from many small and medium urban rivers, and identified the Philippines — and rivers in Metro Manila, including the Pasig — as major contributors. Single-use sachets, widely used for small quantities of household goods, are hard to collect and recycle. Gaps in waste collection, especially in informal settlements along waterways, mean waste enters rivers and drainage channels, worsening flooding and marine pollution.
High severity. Serious, widespread effects requiring sustained action. Severity is descriptive editorial metadata summarising documented effects. It is not a measured index or a score.
02 · Causes
Why it is happening
- 01
Gaps in waste collection
Informal settlements and dense neighbourhoods may lack regular collection.
- 02
Single-use sachets and packaging
Low-value, multilayer packaging has little recycling value.
- 03
Proximity of settlements to waterways
Homes built along rivers and creeks make direct discharge more likely.
- 04
Heavy rainfall
Monsoon and typhoon rains flush waste from streets into rivers.
03 · Impacts
Who and what it affects
- 01
Marine pollution
Plastic entering Manila Bay harms marine life and fisheries.
- 02
Worsened urban flooding
Waste clogs waterways and drains.
- 03
Health risks
Waste accumulation creates breeding sites for disease vectors.
04 · Solutions
Documented approaches
Ecological Solid Waste Management Act implementation
Segregation at source, barangay-level materials recovery facilities and collection.
Expected effectIncreases capture of waste before it reaches waterways.
Extended producer responsibility
The Philippines' 2022 EPR law requires large companies to recover plastic packaging.
Expected effectShifts responsibility for packaging waste to producers.
River rehabilitation
Clearing waterways, relocating at-risk settlements and building esplanades along the Pasig River.
Expected effectReduces direct dumping and improves water quality.
05 · Key indicators
What can be measured
- Research finding
- Philippines identified as a major source of riverine plastic emissions2021
Meijer et al., Science Advances. Model-based estimates carry significant uncertainty.
06 · Sources
Where this comes from
- [1]More than 1000 rivers account for 80% of global riverine plastic emissions into the oceanScience Advances (Meijer et al.) · Apr 2021doi.org(opens in a new tab)
- [2]Department of Environment and Natural ResourcesRepublic of the Philippinesdenr.gov.ph(opens in a new tab)
- [3]What a Waste 2.0: A Global Snapshot of Solid Waste Management to 2050World Bank · Sept 2018openknowledge.worldbank.org(opens in a new tab)
Links open the publishing organisation's site. Some point to the publisher's main page, where the named report or dataset can be found.