Drinking water treatment involves the removal of contaminants and the inactivation of microbes that can cause harm to human health. The goal of water treatment is to produce pure water that will reduce or eliminate potential adverse health effects. Microbial pathogens are among the most common contaminants in water, and most of them can be attributed to human waste. The process of removing these substances usually involves using reactive chemical agents such as chlorine. These treatments also remove suspended solids, including bacteria, algae, fungi, and viruses.

The initial steps of water treatment are the same for all types of sources. Surface water must be pumped from the source and screened through steel bars that are about one inch apart. Then it must be filtered and disinfected to eliminate contaminants. Some methods use finer screens to remove leaves, sediment, and other particles. During this process, the wastewater is diluted and then discharged back into the water supply. However, the final step of water treatment is the removal of large debris before discharge.

Before entering the final treatment stage, surface water must be filtered. Often, filtration is used to remove fine particles, such as leaves and other organic matter. In some cases, water is filtered several times. The process is called sedimentation. It is the process of separating dissolved particles from larger ones and removing the rest. Depending on the source, this process may be repeated as necessary to remove the remaining contaminants from the water.

In a second step, surface water is screened. This removes dissolved solids by neutralizing the negative charge on suspended solids. This helps remove bacterial and other harmful microorganisms that remain in the water. The next step is to apply chemical coagulants. These chemicals are applied in a rapid mixing process, allowing them to disperse in the water. Powdered activated carbon is a good absorbent of synthetic contaminants and other taste-causing chemicals.

There are many types of water treatment. Pretreatment involves removing dissolved chemicals and bacteria from the water. The resulting water is then screened through a series of screens. Typically, the filtration process involves sand filtration and the addition of chemical products to control the growth of bacteria. This step is the most important part of the entire process, and it is the most important step in ensuring that the water is safe for human consumption. This process is a crucial step in drinking-water treatment.

Summary:
Water treatment is the process of removing biological and chemical contaminants from the water. The water is flash-mixed with a polymer or coagulant, then passed into a flocculation basin. The slow turning of the water mixes the chemicals and forms a "floc" at the bottom of the basin. The floc settles at the bottom of the basin, making the whole process more effective.