Reclaimed water for drinking? The concept generates a gather mixed response. On one hand are people who are ready to embrace this new concept because it helps them save the environment. On the other hand, are people who get that icky factor just by the thought of it.
Can water truly be reclaimed? Can it have purified from mere sewage to pure drinking water? The answer is yes. Not only is it purified to the best standards but it is also a breakthrough in water conservation.

How is Wastewater converted into Drinking Water -The Process

Is reclaimed water safe for drinking
Result after each step to obtain drinkable reclaimed water(Right to left)

1. Primary treatment

The first step of water reclamation is passing the sewage through an initial and advanced primary treatment. In this step, all the large particles are separated from water. Next, the water enters sedimentation tanks where certain chemicals make the primary sludge settle towards the bottom (hence the name sedimentation) and scum is made to rise to the top. The water is then separated. By now, 80% of the solid waste has been removed. At this stage, the wastewater is clean enough to be discharged into the oceans. In fact, all sewage treatment plants perform this process. The difference is that there water treatment stop at this very step but here, the purification is taken to the next level.

2. Secondary Treatment

This is another wave in the purification process. Here, certain bacteria are added to the wastewater to ingest organic solids. This produces a secondary sludge which usually deposits at the bottom.
Water water reclamation treatment plant to produce Tertiary Effluent water
Water reclamation treatment plant to produce Tertiary Effluent water

3. Tertiary Treatment

The third step filters all the remaining solids from the water, injects chlorine to disinfect it and finally removes the salt. The water which passes tertiary treatment is fit for agriculture and irrigation purposes.

4. Microfiltration

The tertiary treatment is not the end of it. Tertiary-treated water undergoes advanced water technology. This involves microfiltration that strains out any remaining solids the water may be contaminated with. 


Planet Earth has now around 500 “dead zones,” the equivalent to the territory of the United Kingdom.

Read more facts : Water pollution UK

5. Reverse Osmosis

The most important step is this – reverse osmosis. It applies pressure to water on one side of a membrane and allows pure water to pass through. All the virus, bacteria, protozoa, and pharmaceuticals are left behind. Finally, the water is disinfected using ultra-violet light (UV) or ozone and hydrogen peroxide.

6. Introduction to groundwater

The water is then introduced into groundwater reservoirs where it is further purified by layer after layer of soil. After a span of half a year, the water is sent to drinking water supplies. This is done mainly to relieve public anxiety and their reluctance about drinking recycled water.

“I have been drinking reclaimed water for over 6 months now. Initially, I must say I was a little skeptical. But now I can proudly say that I have made the right choice. It tastes similar to regular freshwater and I haven’t had any health issues since I started consuming it.”
Emily, Singapore
Emily, Singapore

Countries which supply reclaimed water for drinking purposes

Once drawn from groundwater, the recycled water goes through the standard water purification process. You see the elaborate purification process that follows? It makes reclaimed water fit for human consumption.

1. San Diego

While many are still stuck in a dilemma, San Diego has stopped contemplating and is already drinking recycled water. The city used to import 85% of its water from North California and the Colorado River. The water could be contaminated by disposals from Las Vegas but it was treated for drinking purposes.  

And then the restrictions on North California water were imposed. Colorado river also faced a severe drought. Seeing that it couldn’t rely on these water supplies, San Diego, which was already recycling sewage water for irrigation, invested another $11.8 million into an IPR study to use reclaimed water for drinking purposes. Today, its Advanced Water Purification Facility produces 1 million gallons of purified water each day. This is economical as well as eco-friendly.

2. Orange County, California

Orange County in California took a bold step to deal with its growing population and salt intrusion into the groundwater. It started supplying reclaimed water for drinking purposes. This was no easy task but the government decided to invest in a grand $480 million state-of-the-art water reclamation facility. It costs approximately $29 million a year to operate. But before supplying reclaimed water, a stringent purification process must be adhered to. So, after advanced water treatment, they divert half of the recycled water into the aquifer to create a barrier against saltwater intrusion. What happens to the other half? It is diverted to a percolation pond for where the soil further filters it. This natural filtration takes time but the water is ready to be consumed in about 6 months. By this year, the facility is expected to produce 85 million gallons a day.

3. Singapore

Singapore has no natural aquifers (that means no groundwater for drinking) and a small sized landmass. Providing a clean water supply to its people has always remained a problem for the country. However, the solution came out in 2003 when Singapore opened its first plant to produce “NEWater”, i.e. recycled drinking water.

The water was purified by advanced membrane techniques which includes micro-filtration, reverse osmosis and UV disinfection. After it is thoroughly treated, the water diverted towards the reservoirs.

NEWater passed more than 65,000 scientific tests and exceeds World Health Organization (WHO) drinking water standards. Research suggests that it is clean enough to be used for the electronics industry and also to be bottled as drinking water. Because of the breakthrough technology used, it is expected to produce 2.5% of Singapore’s total daily consumption this year.

4. Namibia

Africa has a reputation for being fry but Namibia, which lies towards its south is more arid than any other place in the entire continent. However, people in Namibia have been drinking recycled water ever since 1969. Over 35% of drinking water in Windhoek, the capital city of Namibia, comes from its water reclamation plants. Till date, the country has known no negative or adverse health impacts which are associated with the consumption of recycled water.

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