10 Causes of Water Pollution in the Philippines

In this article we are going to explore on the causes of water pollution in the Philippines. The Philippines is a country comprised of 7,107 islands in Southeast Asia in the western Pacific.

The country is surrounded by water: the Luzon Strait, the South China Sea, the Sulu Sea, the Celebes Sea and the Philippine Sea.

According to the United Nations, uncontrolled, rapid population growth has contributed to extreme poverty, environmental degradation and pollution in the Philippines.

Water pollution is seen when dangerous chemicals and microorganisms reach waterways, so that they contaminate bodies of water such as rivers, lakes, seas, and oceans. The quality of water thus deteriorates and becomes toxic for both humans and the environment.

Water pollution is a major problem in the Philippines, according to Water Environmental Partnership Asia (WEPA), water pollution’s effects cost the Philippines approximately $1.3 billion annually.

The government continues to try to clean up the problem, implementing fines to polluters as well as environmental taxes, but many problems have not been addressed.

Around 50 of the 421 rivers in the Philippines are now considered to be “biologically dead,” supplying sufficient oxygen for only the most hardy species to survive there.

How severe is Water pollution in Philippines?

In an Asia Development Bank report, the Philippines’ regional group  which includes Cambodia, Indonesia, Laos, Malaysia, Myanmar, Thailand and Vietnam has made gains in improving water security.

However, the region is home to a sixth of the global population and the poorest people in the world. With agriculture consuming a staggering 80 percent of the region’s water, the region is a global hotspot for water insecurity.

Due to water pollution in the Philippines, the country is likely to face a shortage of water for sanitation, drinking, agriculture and industrial purposes in the next ten years.

Causes of Water Pollution in the Philippines.

Causes of Water Pollution in the Philippines

Annually there has been an estimate of 2.2 million metric tons of organic water pollution that occur in the Philippines.

With each type of pollutant having different toxic and adverse effects on human health, animals and the environment, result in high economic costs for both the population and government entities.

Water pollution in the Philippines has been discovered to be caused by several factors which we have listed and discussed below. Some of the factors include:

  • Plastic Pollution
  • Unlawful Dumping of Waste in Water Bodies
  • Untreated Raw Sewage
  • Wastewater from Industries
  • Nutrient  Pollution
  • Agrochemical Pollution.
  • Domestic Wastewater
  • Heavy Metal Contamination
  • Run off from Rain and Groundwater
  • Oil Spillage
  • Sediment
  • Rapid Development

1. Plastic Pollution

According to research in the Science Advances journal of the AAAS released in April 2021, the Philippines is home to 28% of the world’s rivers that are polluted by plastic.

Which makes the country one of the biggest plastic pollutants on the planet, with 0.28 to 0.75 million tons of plastic escaping into the waters each year from coastal locations in Manila Bay together with hundreds of thousands of tons of plastic waste that are dumped in the country’s rivers.

In the 2021 research from Oxford University, Our World in Data, showed that Asian rivers contain 81% of all the plastic that reaches the oceans, with the Philippines accounting for about 30% of that total.

In addition, the Pasig River’s share of plastic is over 6%, with the remainder coming from other rivers including Agusan, Jalaur, Pampanga, Rio Grande de Mindanao, Tambo in Pasay, Tullahan, and Zapote.

The 27 km Pasig river that runs through the nation’s capital was once a vital commerce route but the river has now been polluted due to inadequate sewage systems and urbanization.

Locals collect rubbish from the banks of the river every morning, filling bags in their never-ending quest to clean up a stream that is also a key source of plastic waste. Pasig River is known as the most Polluted river in the Philippines, it is majorly polluted with plastics.

Pasig River the most Polluted river in the Philippines

Also data shows that both biodiversity and the quality of water in the streams that feed into Laguna de Bay the Philippines’ largest lake – are deteriorating.

A significant factor in the country’s declining species diversity is plastic waste which makes its way to the ocean where it is consumed by birds and other sea life. 

During the process of degradation, plastic particles acquire new chemical and physical characteristics that may increase the risk of becoming hazardous to living things.

Fishermen have complained that plastics are suffocating the coral reefs which has an impact on the ecosystem as a whole as well as causing a decrease in fish yields.

2. Unlawful Dumping of Waste in Water Bodies

In the Philippines’ poorest communities, waste is rarely collected, and sometimes not at all, resulting in unlawful dumping. This waste ultimately enters into the maritime ecosystem and has detrimental effects on both the fishing industry and environmental tourism.

The Pasig River and the Marilao River are examples of rivers polluted by this factor. This is as a result of the cities growing population which invariably leads to urbanization. As many locals are seen to empty the waste on the following water.

3. Untreated Raw Sewage

Due to a lack of sufficient and effective sewage treatment infrastructure, only about 10% of the sewage in the Philippines is properly treated.

Much of this waste is directly discarded into waterways, particularly in low income urban areas that lack sufficient infrastructure to support proper treatment of this waste.

Such waste can spread disease-causing organisms and can cause waterborne diseases, such as gastroenteritis, diarrhea, typhoid, cholera, dysentery, and hepatitis.

An estimated 58% of the groundwater in the Philippines has been contaminated with coliform bacteria and should be treated. The Pasig River too is also polluted by untreated domestic and industrial sewage.

4. Wastewater from Industries

Specific pollutants vary by each industry, but common industrial pollutants include chromium, cadmium, lead, mercury and cyanide the metal varies according to industry. Such pollutants are dumped directly into water bodies on a daily basis.

Marilao River is an example, it is defiled by various waste coming mainly from fur and textile factories which flows past Bulacan province in Philippines.

Nowadays, almost no oxygen is present in the river so no life form can exist therein. Marilao River is thus one of the 50 dead Philippines’ rivers.

5. Nutrient  Pollution

Nutrient pollution is a major concern. Nutrients such as nitrogen and phosphorus can result in the eutrophication, or over-enrichment of a water body, triggering dense plant growth and the death of animal life from lack of oxygen.

There have been numerous reports of fish die-offs in Laguna de Bay as a result of this factor.

Key sources of nutrients include run-off from farmland treated with fertilizers as well as detergents and untreated sewage in domestic wastewater.

UN Environment has been studying concentrations of nitrogen in the lake as well as nutrients entering Manila Bay to the west of the city as part of the Global Nutrient Cycle Project.

The project, funded by the Global Environment Facility, is developing policies and practices to reduce the impact of nutrients on ecosystems.

Serious pollution in a lake next to the mega-city of Manila is forcing a rethink by development planners to protect water quality and fish stocks.

For example in the Laguna de Bay which is the Philippines’ largest lake, and supplies Metro Manila’s 16 million people with a third of their fish.

It also supports agriculture, industry and hydro-power generation, and is a welcome getaway for rest and recreation for many Filipinos. Millions more live around its 285-kilometre shoreline.

But the lake’s importance has placed it in peril from a host of problems, including pollution from untreated sewage and industrial waste, over-fishing and the sedimentation and illegal reclamation that are eroding its capacity.

Laguna de Bay Lake in the Philippines

6. Agrochemical Pollution

According to the report, water pollution from agrochemical runoff is more widespread in the Philippines than previously thought. 

Decades of agrochemical use in the Philippines and Thailand has polluted water sources in the country and are directly posing risks to human health and the environment,

 “Agrochemical use in the Philippines And Thailand and its consequences to the environment” provides an overview on how the staggering increase in the use of synthetic farm chemicals in the past few decades has not resulted in a similar increase in crop yields, and worse, cause substantial environmental damage to the country’s water sources.

“This model of agricultural growth is fatally flawed because of declining crop yields and massive environmental impacts.

Aside from causing land degradation and losses in soil fertility, The Pampanga River, Philippines is an example of the river polluted due to surface runoff of organochlorine pesticides residues.

6  Domestic wastewater

Wastewater from households can contain organics which are decomposed naturally in the sewage by bacteria and other microorganisms, the dissolved oxygen content of the water is depleted.

This endangers the quality of lakes and streams, where high levels of oxygen are required for fish and other aquatic organisms to survive. Manila’s notorious Pasig River is an example.

7. Heavy Metal Contamination

The rivers in the capital city of Manila have received some attention lately. For instance, the Marilao River which runs through the Bulacan Province and into Manila Bay was on the 10 Most Polluted Rivers in the World list.

The river is contaminated with several kinds of heavy metals and chemicals from tanneries, gold refineries, dumps and textile factories.

8. Run off from Rain and Groundwater

According to government monitoring data, up to 58% of the groundwater tested was contaminated with coliform, and approximately one third of illnesses monitored during a five-year period were caused by water-borne sources.

The type of pollution is known as Non-point sources of water pollution. This type of pollution can contain some of the same toxic chemicals that industrial wastewater contains.  

Recently, researchers at the Benguet State University have found pesticide residues of organophosphates, organochlorines and pyrethroids in soil and vegetables grown in certain municipalities.

Pesticide exposure causes health problems, and both acute and chronic toxic effects have been reported in the Philippines.

Also in the process of Fracking  that is the extraction of oil or natural gas from rock. The technique uses large amounts of water and chemicals at high pressure to crack the rock.

The fluid created by fracking contains contaminants that can pollute underground water supplies. Example of some rivers affected in the Philippines are Naguillan, Upper Magat, and Caraballo rivers.

8. Oil Spillage

Oil pollution can occur when oil tankers spill their cargo. However, oil can also enter the sea through factories, farms, and cities, as well as through the shipping industry. These can include spills from oil and other chemicals.

For instance, a large oil spill from a tanker carrying 800,000 litres of industrial oil that sank off the coast of Oriental Mindoro province in southwest Philippines is threatening the biodiversity of 21 nearby marine protected areas and the livelihoods of Filipinos working in the fishing and tourism sectors.

This has been known as the largest oil spill in the Philippines which also affected some parts of the Pasig River.

9. Sediment

To halt rapid sedimentation, authorities have drawn up plans to build small dams on tributaries to filter out debris and reduce the amount of soil entering the lake. Reforestation along parts of the shore has also been considered.

The Laguna Lake Development Authority is the principal body working towards the sound ecological governance and sustainable development of the lake. The Authority drew up a 10-year master plan in 2016. Education is an important part of its work.

10. Rapid Development

According to Water Environment Partnership in Asia (WEPA), 32% of the Philippines’ land mass approximately 96,000 square kilometers is used for agriculture.

The primary crops are palay (rice), corn, sugar cane, fruit, root crops, vegetables and trees (for rubber). Increased population, urbanization, agriculture and industrialization have all reduced the quality of water in the Philippines.

The Philippines as a developing nation that has experienced a rapid rise in urbanization and industrialization as its population has grown rapidly.

Unfortunately, this rapid development has come at a price of increased water pollution, with 47% of all surveyed water bodies in the country having good water quality, 40% having only fair water quality, and 13% having poor water quality.

According to Water.Org a global non-profit organization that aims to deliver water and sanitation to the world, although the Philippines’ economy is registering rapid growth, it still faces massive obstacles in terms of access to water and sanitation due to the high level of water pollution.


The Philippines currently registers the fastest economic development among its ASEAN peers but this rapid development, along with an increasing level of urbanization, is leading to the pollution of waters with toxins coming from plants and farms, as well as tons and tons of plastic, which can all contaminate the soil and seep into water ending up in the world’s oceans.

The government is aware of this issue and for several years has been taking action to deal with it by restoring Manila Bay, among other areas, and has ambitious plans to restore rivers across the country.

There are a number of actions that the nation of the Philippines can take to address its national problems associated with water pollution.

The people of the Philippines need to be made aware of the health and economic impacts of water pollution, and they should be encouraged to be become involved in decision making processes that affect water management policies.

Stakeholders across all sectors also need to work together in order to prioritize and adopt actions affecting water quality.


Environmental Consultant at Environment Go! | + posts

Ahamefula Ascension is a Real Estate Consultant, Data Analyst, and Content writer. He is the founder of Hope Ablaze Foundation and a Graduate of Environmental Management in one of the prestigious colleges in the country. He is obsessed with Reading, Research and Writing.

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