Sanitizing Polluted Water: A Complex Challenge

Water is essential for life, but it is also vulnerable to pollution. Water pollution occurs when harmful substances, often chemicals or microorganisms, contaminate water bodies, degrading water quality and making it toxic to humans and the environment. This widespread issue is jeopardizing our health, killing more people annually than war and other forms of violence combined. Polluted water is challenging to sanitize due to the diverse nature of contaminants, which can include chemicals, waste, plastic, and other pollutants. While boiling and chemical disinfection can kill most germs, they may not be effective against all parasites and other microorganisms. Additionally, boiling and disinfection methods do not remove heavy metals, salts, and most chemicals. The vulnerability of water to pollution and the varying effectiveness of sanitation methods highlight the urgency of addressing water pollution to protect human health and the environment.

Why is polluted water hard to sanitize?

Polluted water contains harmful substances

Water is known as a "universal solvent," able to dissolve more substances than any other liquid on Earth. This means that toxic substances from farms, towns, and factories readily dissolve and mix with water, causing pollution. The agricultural sector is the biggest consumer of freshwater resources, with farming and livestock using about 70% of the Earth's surface water supplies. However, it is also a serious water polluter. In the United States, agricultural pollution is the top source of contamination in rivers and streams.

Domestic sewage is another major source of water pollution, as it contains pathogens (disease-causing microorganisms) and putrescible organic substances. Sewage can promote algae growth, which can eventually result in "dead zones" where aquatic life cannot survive due to a lack of oxygen. Microplastics are often found in marine wildlife and can become concentrated in humans who consume seafood.

Inadequate management of urban, industrial, and agricultural wastewater means the drinking water of millions of people is contaminated or chemically polluted. Groundwater, which is a source of drinking water for many, can become polluted when contaminants like pesticides, fertilizers, and waste leached from landfills make their way into an aquifer.

To sanitize polluted water, it is recommended to use bottled, boiled, or treated water to avoid getting sick. Boiling water is the best way to kill germs, but chemical disinfectants like chlorine bleach, iodine, or chlorine dioxide tablets can also be used.

Boiling water is not always possible

Additionally, boiling water is not effective at removing all types of contaminants. While it is an excellent way to kill germs and bacteria, boiling does not remove heavy metals, salts, or most other chemicals. This is a significant limitation, as chemical pollution is a widespread issue, with agricultural pollution being the top source of contamination in rivers and streams.

In some cases, boiling water may not be possible due to a lack of resources or time constraints. For instance, in areas without access to a heat source or fuel, boiling large quantities of water may not be feasible. Similarly, in emergency situations, such as natural disasters, boiling water may not be an option due to the urgency of the situation.

Furthermore, boiling water can be unsafe for certain materials. For example, submerging glass bottles in boiling water can cause them to break or develop microfractures, which can be dangerous. In such cases, alternative sanitization methods, such as chemical washes or UV light treatment, may be more suitable.

Overall, while boiling water is a simple and effective method of sanitization in many cases, it is not always possible or practical. It is important to consider the specific circumstances and choose the most appropriate method to ensure safe and effective sanitization.

Boiling water does not remove all contaminants

Boiling water is an effective way to kill most germs, bacteria, viruses, and other pathogens. However, boiling water does not remove all contaminants and is not a foolproof method of water purification.

Firstly, boiling water is not effective in addressing gross levels of contamination, such as raw sewage or high turbidity. In such cases, boiling water may be impaired in its effectiveness due to particulate matter, and alternate water sources must be used.

Secondly, boiling water will not remove heavy metals, salts, or most chemicals. Lead and heavy metals can find their way into water supplies through old, corroded pipes, and boiling will not eliminate these contaminants.

Thirdly, boiling water is not a form of sterilization, but rather pasteurization. While pasteurization kills organisms harmful to humans, it does not kill all organisms present. For example, boiling water may not be sufficient to kill certain parasites, such as Cryptosporidium and Giardia, which are resistant to chlorine and iodine-based disinfectants.

Finally, boiling water is not always practical or accessible in emergency situations, such as natural disasters or interruptions to regular water service. In these cases, bottled water or other methods of water disinfection, such as chemical tablets or liquid drops, may be necessary. It is important to follow the instructions and recommendations provided by local authorities and health departments to ensure safe water for drinking, cooking, and personal hygiene.

Water sources are often far from home

Water treatment plants play a crucial role in ensuring that the water we receive at home is safe to use. The water is collected, filtered, cleaned, treated with chemicals, and stored in tanks. Fluoride is added to prevent tooth decay. After treatment, the water is sent to a pump station, which pressurizes it and sends it through the city's water mains. From there, it enters an underground supply pipe leading to each home.

While modern water treatment methods have improved significantly, the delivery process still relies on ancient systems. This means that water sources are often far from the end user, and the journey from the treatment plant to our homes can be lengthy. This distance can also impact the quality of the water, as it increases the potential for contamination along the way.

Water pollution is a significant issue, and our water sources are vulnerable to a variety of pollutants. Toxic substances from farms, towns, and factories can easily dissolve into and mix with water, causing degradation. Agricultural pollution, for instance, is the top source of contamination in rivers and streams in the United States.

To address water pollution, it is essential to understand your local watershed and take steps to protect your source water. This includes learning about the unique qualities of the water in your area, such as its source, wastewater treatment processes, and stormwater flow. By building awareness and taking collective action, we can work towards preventing water contamination and reducing our contribution to this global issue.

Water is vulnerable to pollution

Water is known as a "universal solvent", meaning it can dissolve more substances than any other liquid on Earth. This is why it is so vulnerable to pollution. Toxic substances from farms, towns, and factories readily dissolve into and mix with water, causing pollution.

Agricultural pollution is a leading cause of water degradation worldwide. Farming and livestock production use about 70% of the Earth's surface water supplies, and they also contaminate them. In the United States, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and the third main source in lakes. It is also a major contributor to contamination in estuaries and groundwater. Every time it rains, fertilizers, pesticides, and animal waste from farms and livestock wash nutrients and pathogens, such as bacteria and viruses, into our waterways.

Nutrient pollution, caused by excess nitrogen and phosphorus in water or air, is the number-one threat to water quality worldwide. It can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife. Chemical dumping from farms, towns, and factories is one of the main causes of eutrophication of water. The UN states that more than 80% of the world's sewage finds its way into seas and rivers untreated.

Water pollution is a widespread problem that jeopardizes our health. Unsafe water kills more people each year than war and all other forms of violence combined. It is a leading cause of diseases such as diarrhoea, cholera, dysentery, typhoid, and poliomyelitis, which kill more than 500,000 people worldwide annually.

Frequently asked questions