Countries & Cities With The Most Water Pollution & Contamination (& Worst Tap Water & Drinking Water)

Level of water pollution and water contamination of a city is one of the factors that contributes to how sustainable or green a city is.

Some countries and cities around the world have higher levels of water pollution and contamination than others.

Reasons or causes for pollution differ in each different geographic location (i.e. water pollution problems are localized)

This guide outlines some of the cities and countries with the greatest levels of water pollution and contamination.

We also look at some of the top water polluting countries i.e. the biggest water polluting offenders

(Note – this guide contain general information only, and not professional advice)


Summary – Countries & Cities With The Most Water Pollution & Contamination

Water pollution and contamination in different cities and countries can involve pollution to fresh water, or ocean pollution/contamination

Although ocean pollution is important to address, fresh water pollution is arguably more important to address because we depend on fresh water so heavily for so many things in society (drinking water being a major use of fresh water)

Fresh water pollution and contamination also contributes to global water problems like water stress and scarcity, as well as a number of other water issues 

There’s many different ways that water pollution and contamination can occur, and ultimately, each local geographic area has their own causes, effects, problems and solutions to consider

What we see below in this guide is that water pollution and contamination is not specific to particular country or city – it happens almost everywhere – and, each location has different causes of pollution or contamination … it can even happen at the public water supply pipe level via leaching of chemicals and compounds into treated drinking water in developed and high income countries.

So, it doesn’t discriminate.

In addition to different causes in different locations, different water sources in these locations (cities, towns, regions) can be degraded from pollution and contamination in different % shares i.e. one body of water might be 100% adequate for drinking, whilst another body of water might be of completely inadequate quality for drinking

The biggest water polluting countries in the world right now (according to some reports) are China, the United States, India, Japan, Germany, Indonesia, Brazil

Something that we haven’t examined in this guide that we probably could expand on is the top water polluters within major geographic areas – agricultural producers/farms, companies, and other parties.

This might help address the problem of water pollution/contamination in a local area on a deeper level


Firstly, Be Aware There Are Different Types Of Water Sources

There’s two main types of water sources in the world:


Saltwater/marine water


Freshwater can be for drinking water and household use, or it can also be used for uses such as irrigation in agriculture, and for industry applications.

It can come from groundwater reservoirs and dams, or surface water sources such as rivers and lakes.

Saltwater is the world’s oceans and other highly saline water sources.

This guide is mainly concerned with fresh water pollution and contamination.


Types Of Water Pollutants & Causes Of Water Pollution

There are many different types of water pollutants, and water pollutants can often be found in different types of waste products and materials.

The general types of water pollutants, their sources and how they usually pollute water sources are summarised in this guide.

The specific causes of water pollution though can differ depending on the country or city.

The listed guides below outline some of the causes of water pollution in different parts of the world.


Countries & Cities With The Most Water Pollution lists the cities with the most water pollution in no particular order:

(We’ve also outlined some of the causes of pollution for some places in brackets)

– Africa, Central & South America

Johannesburg, South Africa [waste water and untreated sewage from small amount of filtration available] 

Algiers, Algeria [drought and overuse]

Harare, Zimbabwe [industrial discharge from factories]

Port Au Prince, Haiti [natural disasters]

Bogota, Colombia [industrial waste water]

Mexico City, Mexico [overuse of groundwater, natural drought, and the risk of flooding from natural disasters]

Tunis, Tunisia [industrial dumped wastewater and chemical byproducts]


– United States Cities

Jacksonville, FL [cleaning chemicals]

Omaha, NE [agricultural chemicals like fertilizer, pesticides, and herbicides]

Reno, NV [dry cleaning wastewater and the agricultural chemicals]

Houston, TX [nuclear power plant and factory waste]

Riverside, CA [power plants and industrial activity contribute to industrial dumping and toxic run off]

Las Vegas, NV [chemical waste and radiation pollution]

Pensacola, FL [Freshwater – factory wastewater and runoff, agricultural runoff from nearby farms, and leaking chemical storage containers. Ocean water – oil spills]


– Asia and the Middle East

Ulan Baatar, Mongolia [mining waste]

Vientiane, Laos [agricultural waste]

Dhaka, Bangladesh [household and sewage waste, industrial dumping, natural disasters, and oil spills]

Jakarta, Indonesia [Industrial and factory waste, and open defecation]

Manila, Philippines [Fresh water – Agricultural dumping, industrial dumping, and household garbage. Ocean – oil spills]

Kabul, Afghanistan [Open defecation, Leaky septic systems and politics]

New Delhi [drought, open defecation, a lack of sanitation and water treatment, and domestic sewage]


Read more about where water pollution occurs in these cities, the biggest causes of the water pollution, types of pollutants, how widespread water pollution is there, and health risks here (


Countries & Cities With The Most Water Contamination lists the 25 countries in the world with the most unsafe or contaminated tap water (in no particular order):

(We’ve also outlined some of the causes of contamination for some places in brackets)

Ukraine [industrial and agricultural run-off, and poor infrastructure]

The Bahamas






Cuba [sewage waste]

Puerto Rico [urine, hazardous waste, and runoff]

Taiwan [trace amounts of arsenic]

Costa Rica [some bodies of water have toxic industrial waste]

Argentina [industrial influences, urbanization, and harmful agriculture]



United Arab Emirates



The Maldives [heavy toxic metals]

Belize [oil based lead paint from rooves collecting water]


Panama [agricultural runoff]


Dominican Republic

Moldova [nitrates, ammoniac, and fluorine]

… Reasons for unsafe tap water and contaminated water range, but might include sewage discharge in the water, industrial waste, agricultural waste, arsenic or lead from water pipes, a lack of water treatment infrastructure, other hazardous waste, runoff, and bacteria and water borne diseases.


The US isn’t safe from water supply contamination.

These cities and areas have had allegations of water supply contamination recently:






Washington DC

Brady, Texas


Dos Palos, California

Charleston, West Virginia

Newburgh, Upstate New York



Cities & Countries With The Worst Tap Water & Drinking Water

Read more in this guide about the cities and countries with some of the worst tap water and drinking water.


Biggest Water Polluting Countries also lists the biggest water polluting countries in the world.

These are (in no particular order):

7 Biggest Water-Polluting Countries


United States







How Much Of The World’s Freshwater Sources Are Contaminated Or Polluted? (What %?)

There’s no one number that expresses what % or exactly how much of the world’s freshwater sources are contaminated or polluted.

This is however various reports and stats on water pollution and contamination in various countries, cities and regions around the world:


Some 80 percent of the world’s wastewater is dumped—largely untreated—back into the environment, polluting rivers, lakes, and oceans. (


In Developing Countries

70 percent of industrial wastes are dumped untreated into waters, polluting the usable water supply (


In the US

… potentially harmful contaminants—from arsenic to copper to lead—have been found in the tap water of every single state (


In the US

Surface water from freshwater sources … accounts for more than 60 percent of the water delivered to American homes. … nearly half of rivers and streams and more than one-third of lakes are polluted and unfit for swimming, fishing, and drinking (


Omaha, Nebraska

Manganese was found at levels more than forty percent the legal amount in Omaha water samples.

Atrazine and nitrates also surpass the legally safe amounts that can be present in water. (



Indonesian water makes up 6% of the water in the whole world.

However, these water resources degrade by at least 15% and up to 35% every year. (



Over 21 percent of the country’s diseases stem from the water supply (



80 percent of the drinking water in the country’s villages is not safe for consumption.

“The quantities of nitrates, ammoniac, and fluorine are two or even three times higher than the norm (



Almost 90% of underground water in cities are affected by pollution and as well as 70% of China’s rivers and lakes ( 


Beijing, China

In Beijing, one of China’s largest cities, almost 40 percent of the water was so dirty in 2015 that it couldn’t be used for any purpose. (


Vientiane, Laos

The percent of the water that has been polluted in Vientiane is just over 72% (


Jakarta, Indonesia

Because of open defecation, around 90% of the groundwater in Jakarta is polluted with E. coli bacteria.

Three percent of child deaths annually occur from pollution in this river. (


Kabul, Afghanistan

Water pollution percentage comes in at 85%, which is incredibly high.

Of the water used for drinking, 81% is still polluted. (


Mexico City, Mexico

There are 19 million people living in Greater Mexico City. 23% of the wells in the region don’t meet the national standards for bacteria presence. (


Manila, Philippines

50% of the rivers in the Philippines are considered biologically dead, and unfortunately, the Marilao River is one of them. (


Note that marine water pollution and contamination is a separate issue altogether from freshwater contamination/pollution.

Also, note the difference between access to clean water, and water pollution/contamination.

A certain number of people in a country or city may not have access to clean drinking water, but that isn’t always because of water pollution/contamination.

It can be for a range of reasons such as water scarcity, lack of money, poor political management of water systems and issues, poor water infrastructure and other reasons.

Furthermore, note that some some contaminated and polluted water can be treated and cleaned to become safe for use or drinking water, but some can’t.

It depends on the type and severity of pollution/contamination, and how good/capable the water treatment technology is in that city or region, as to whether water can be treated and cleaned.


Difference Between Water Pollution & Water Contamination

In the context of this article:

We are referring to water pollution as the broader issue that causes a degradation of water quality

And, water contamination being a particular case of pollution that makes that water not suitable for human, animal or plant consumption, or sometimes even contact


Read this resource for a more technical difference between the two (


Countries With Worst Access To Drinking Water Or Clean Water Supplies

Various factors can be assessed to determine how good a city or country’s water supply is, such as accessibility of drinking water, availability when needed and levels of contamination. 

Read more about the places in the world with the worst clean water supplies in this resource

There’s still billions of people in the world without access to clean water.


Causes Of Water Pollution In Major Countries 

According to, some of the causes of water pollution in major countries are

China [Pearl River is contaminated with industrial runoff and wastewater from nearby factories]

United States [Pesticides are one of the biggest pollutants in the United States]

India [open defecation can be a pollutant, and, sewage treatment plants in operation aren’t maintained well]

Japan [ground water is polluted, and eutrophication is a problem in some water sources]

Germany [in many German rivers, 257 toxic compounds were found, and many in high levels. E coli is also an issue]

Indonesia [bathing and washing in water can lead to contamination]

Brazil [landfills lead to higher levels of soil toxicity and polluted groundwater, and, waste is dumped directly into some water sources]


They note agriculture is the biggest cause of water pollution in developed countries (usually from pesticides, fertilizers and agricultural chemical run off), with factories and fuel emissions also playing a major part.

In developing countries, lack of adequate waste management (sewage, waste water etc), and waste from agriculture contribute to water pollution.

You can read more here about the other causes of water pollution.


Solutions To Water Pollution & Contamination

You can read this guide which outlines some of the general and also specific solutions for addressing water pollution and contamination.
















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