How Water Treatment Plants Ensure Safe Drinking Water | Treatment Methods

Water, the fundamental element for sustaining life, is a vital resource supporting all organisms inhabiting Earth. Providing clean and safe water is an inherent right of every individual. However, Natural water reservoirs sometimes exhibit contamination due to the presence of impurities and toxic substances. Therefore, the significance of water treatment facilities is essential in ensuring high-quality standards for the water distributed to communities.

This article examines the intricate procedure of water purification in Water Treatment Plants and analyses its importance in ensuring clean and safe water for all individuals.

Water Treatment Plants
Water Treatment Plants

Treatment of Water Supplies and the Need for Water Treatment Plants

The water sources, likely groundwater, lakes, and river reservoirs, are subjected to various pollution sources, including natural and human-induced factors. Natural contaminants in water systems contains many substances, such as organic matter, algae, and suspended particulates. Human activities may release various substances into water bodies, such as chemicals, heavy metals, and disease-causing microorganisms. Because of this, these pollutants can seriously endanger the health of those who drink contaminated water if the problem is unsolved.

Facilities for water purification are crucial for maintaining public health. They serve as an initial defence against diseases transmitted through the water and contaminants in water sources. Without a doubt, water quality would deteriorate without treatment facilities, threatening people and the environment.

Why are Water Treatment Plants crucial?

Available raw water must be treated before they are supplied to the public. They not only make sure that there is access to clean water, but they also deal with many other crucial issues. Treatment facilities contribute significantly to environmental protection and sustainable development by successfully removing pollutants and dangerous substances. The main reasons for water treatment processes are given below:

a) Public Health Protection

Providing access to clean, safe water is essential for public health. Diseases like Cholera, dysentery, and giardiasis can spread because of contaminated water distribution. Water treatment plants ensure public health by effectively removing or neutralizing microorganisms.

b) Conservation of Environment

Water treatment facilities protect human health and preserve the environment, among many other advantages. Untreated water discharged into rivers and lakes that contain chemicals and toxins can harm aquatic life and disturb ecosystems. These treatment processes successfully reduce the harmful effect on the environment by applying water treatment procedures before discharge.

c) Industrial and Agricultural Support

It has been demonstrated that access to clean water improves several facets of civilization, including production methods, the standard of commodities, and agricultural productivity. This has a big impact on encouraging economic growth and general development.

d) Recreational Activities

Water bodies frequently function as places of recreation for swimming, boating, and fishing. Water treatment facilities play a crucial role in ensuring the health and safety of those accessing recreational spaces by successfully preventing waterborne diseases and fostering the community’s overall welfare.

Methods of Purification of Water in Water Treatment Plants

The process in Water Treatment Plants includes a sequence of distinct stages; each intended to target particular pollutants and preserve the overall integrity of the water. Now, let us look at each stage thoroughly, providing a more comprehensive analysis.

1. Screening in Water Treatment

The first phase in the process of treating raw water is called screening, and it consists of passing the water through big screens to remove material that is visible to the naked eye. This debris includes things like leaves, twigs, and stones. These physical barriers prevent large particles from entering the treatment plant; as a result, it protects the plant equipment and makes subsequent treatment operations easier.

Screens used in Water Treatment Plant
Image of Screening (Source: All about civil)

2. Plain Sedimentation in Water Treatment

The second phase in the process is known as plain sedimentation. In this case, the water is let to remain stationary in a big basin or tank for an extended time. Because the water is not being stirred, gravity causes the larger particles and suspended matter to move downward to the bottom, creating a sludge layer. After that, the water that is clearer at the top is carefully collected so that it may undergo additional filtration.

Sedimentation Tank
Sedimentation Tank Photo by Mike van Schoonderwalt

3. Sedimentation Aided with Coagulation in Water Treatment

Chemical coagulants, which include Aluminium Sulphate (often referred to as alum) or ferric chloride, are frequently introduced into the water before the commencement of the sedimentation process. This method aids in maximizing the efficiency of mud separation.

The coagulants act by neutralizing the negative charges that remain on the surface of the tiny particles. Consequently, the tiny particles accumulate, resulting in floc formation characterized by increased size and weight. During the sedimentation process, the flocs exhibit enhanced settling rates, facilitating the removal of a substantial quantity of pollutants effectively.

4. Filtration in Water Treatment

The water undergoes filtration by being passed through a diverse range of filtering mediums to collect and remove smaller particles and any residual contaminants and flocs. Filtration is a crucial stage throughout the process. The filtering media layers may consist of sand, activated carbon, and multimedia filters, among other possible components. Filtration significantly enhances the quality of water by further reducing the presence of pollutants.

Filtration in Water Treatment
Image of Sand Filtration (Source: iStock)

5. Disinfection in Water Treatment

Even though disinfection is the final stage in the water treatment process, it is still one of the most important steps. Even though the water has been purified using the processes that have gone before, it’s still possible that some harmful microorganisms are present.

Disinfection, which eliminates these potentially harmful microorganisms, ensures that the water has been treated and is safe for human consumption. The most often used disinfectants are ozone, chlorine, and chloramine, all of the chlorine family members. Through the process of disinfection, it is possible to eliminate potentially hazardous bacteria and maintain the quality of the water throughout the distribution process.

 UV Water Disinfection method
Image of UV Water Disinfection method (Source: Eurowater)

6. Aeration in Water Treatment

A remedy for the problem of unwanted gases and organic compounds that are volatile existing in the water is to subject it to the process of aeration. This procedure helps to enhance water’s taste and odour by introducing air into the water. It also increases the release of undesirable gases, including Hydrogen Sulphide, which is a byproduct of the process.

7. Softening in Water Treatment

The presence of calcium and magnesium ions in water can result in water hardness, which can give rise to a range of problems, including pipe scaling and reduced soap efficiency. The process of softening water involves ion exchange, wherein calcium and magnesium ions are substituted with sodium ions by applying specific ion exchange resins. The process mentioned earlier yields water that has been softened, hence enhancing its suitability for a wide range of uses.

Softening in Water Treatment
Image of Water softening process (

8. Miscellaneous Treatments

Water treatment facilities may utilize supplementary treatment methods to meet specific water quality standards in addition to the primary treatment procedures. There exist several treatment alternatives that can be considered, such include:

i. Fluoridation

Fluoridation refers to the addition of controlled amounts of fluoride to the water supply of a given community, aiming to reduce the risk of dental caries and enhance oral health. This initiative proves particularly advantageous in developing better dental care within the populations we serve to.

ii. Recarbonation

After eliminating impurities, the water will undergo a recarbonation process, including introducing more carbon dioxide. The method aids in maintaining the structural integrity of pipes and infrastructure by regulating the pH level of the water and mitigating corrosion inside the distribution systems.

iii. Desalination

Desalination is an advanced technique employed on saline or brackish water sources to extract salt and other minerals, generating fresh and drinkable water. This technique is particularly advantageous in regions experiencing water scarcity, where their survival heavily depends on other water resources.


In brief, the treatment of water is essential for both the maintenance of public health and the protection of the environment. Water treatment facilities are responsible for removing potentially harmful contaminants, toxic substances, and pathogens from the water supply provided in different areas. A thorough set of purifying stages facilitates the attainment of this aim.

The processes in Water Treatment Plants have been developed to ensure the supply of clean and safe water suitable for many applications, including but not limited to drinking water, household use, industrial activities, and agricultural needs.

Frequently Asked Questions

1. What is the significance of the Water Treatment Process?

The process of water treatment is essential in order to remove pollutants and toxins from naturally occurring water sources, hence ensuring the protection of both the public health and the environment. Unquestionably, the absence of treatment for water can give rise to substantial health hazards and cause damage to the ecology.

2. What are the fundamental stages involved in the Water Treatment Process?

The fundamental stages involved in the water treatment process includes screening, plain sedimentation, sedimentation aided with coagulation, filtration, disinfection, aeration, softening, and additional miscellaneous treatments such as fluoridation, recarbonation, and desalination.

3. What is the significance of disinfection in the context of water treatment?

The process of disinfection plays an important role in water treatment process by effectively reducing potentially dangerous microbes and pathogens that may still present even after the initial treatment processes. Evidently, this process guarantees that the water that has undergone treatment is safe for human consumption.

4. What is the mechanism behind water softening?

The process of water softening entails the substitution of calcium and magnesium ions with sodium ions via ion exchange resins. As a result, it reduces the hardness and decreases propensity for scale accumulation. This phenomenon confers advantages to both domestic appliances and industrial operations.

5. What is the significance of desalination?

Desalination plays an important role in areas subjected to water scarcity, as it facilitates the transformation of seawater or brackish water into potable water. This process offers a sustainable solution to populations grappling with restricted access to water resources, therefore ensuring a safe and reliable water supply.