Countries & Cities With The Most Water Pollution & Contamination, & Worst Clean Water Supplies

Countries & Cities With The Most Water Pollution & Contamination, & Worst Clean Water Supplies

Some countries and cities have cleaner water supplies than others.

This is a very concise guide outlining the cities and countries with the most water pollution and contamination.


The Different Types Of Water Sources

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

  • Freshwater
  • 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, dams, rivers, lakes and other water sources.

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


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

Africa, Central & South America

  • Johannesburg, South Africa
  • Algiers, Algeria
  • Harare, Zimbabwe
  • Port Au Prince, Haiti
  • Bogota, Colombia
  • Mexico City, Mexico
  • Tunis, Tunisia

United States Cities

  • Jacksonville, FL
  • Omaha, NE
  • Reno, NV
  • Houston, TX
  • Riverside, CA
  • Las Vegas, NV
  • Pensacola, FL

Asia and the Middle East

  • Ulan Baatar, Mongolia
  • Vientiane, Laos
  • Dhaka, Bangladesh
  • Jakarta, Indonesia
  • Manila, Philippines
  • Kabul, Afghanistan
  • New Delhi

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 at also lists the biggest water polluting countries in the world. These are (in no particular order):

7 Biggest Water-Polluting Countries

  1. China
  2. United States
  3. India
  4. Japan
  5. Germany
  6. Indonesia
  7. Brazil

They note agriculture is the biggest cause of water pollution in developed countries, with factories and fuel emissions also playing a part.

In developing countries, waste management (sewage, waste water etc), agriculture and a lack of dedicated water sources and water infrastructure contribute to water pollution.



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):

  • Ukraine
  • The Bahamas
  • Brazil
  • China
  • Fiji
  • Mexico
  • Russia
  • Cuba
  • Puerto Rico
  • Taiwan
  • Costa Rica
  • Argentina
  • Morocco
  • Thailand
  • United Arab Emirates
  • Peru
  • Egypt
  • The Maldives
  • Belize
  • Kenya
  • Panama
  • Nicaragua
  • Dominican Republic
  • Moldova

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:

  • Pittsburgh
  • Milwaukee
  • Flint
  • Detroit
  • Newark
  • Washington DC
  • Brady, Texas
  • Baltimore
  • Dos Palos, California
  • Charleston, West Virginia
  • Newburgh, Upstate New York



Water Pollution & Contamination In Developed vs Developing Countries

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

Laws and regulations regarding industrial waste and hazardous waste dumping tend to be stricter in developed countries.

However, trace contaminants such as pharmaceuticals, things we throw down the sink, household cleaning products, and also major pollutants like agricultural run off, run off from vehicles tend to be more of an issue in developed countries.

Read more about the causes of water pollution and contamination in developing vs developed countries in this guide.


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:

  • Worldwide – 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. (
  • Indonesia – 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. (
  • India – over 21 percent of the country’s diseases stem from the water supply (
  • Moldova – 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 (
  • China – 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 The Best & Worst 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:


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














Leave a Comment