Water Recycling is Paving the Way for a Sustainable Future

Our current economic model uses a linear approach involving four processes: production, harvesting or extracting natural material; distribution; consumption; and disposal.

While this model contributed to unprecedented growth and development, it has also led to the massive generation of waste, pollution, and environmental degradation that could affect natural sources and lead to resource scarcity.

Growing demands from population growth, food production, and the effects of climate change are straining freshwater sources and increasing water scarcity. To protect our water resources and ensure sustainability for many generations, we need a new model—a circular economy in which waste is treated as a resource.

For instance, wastewater that would otherwise be discharged can be recycled or reused when treated properly and used for agricultural, commercial, or domestic purposes. Recycling water can help address water scarcity, the impacts of climate change, and the growing demands of population growth. It drives sustainability, conserves freshwater resources from surface water and groundwater, reduces environmental impact, and strengthens agricultural resilience.

Sludge from wastewater can also be turned into a valuable resource like fertilizer. Instead of being thrown in landfills, contributing to emissions and pollution, it can be processed and repurposed to support agriculture.

Countries with the most water recycling

Farmers in the United States have been irrigation their crops with water for nearly 40 years. California and Florida are the top water recyclers in the US. They use 587.76 million gallons of recycled water per day for agricultural irrigation, with the amount expected to increase.

Israel is the world leader in wastewater recycling. Nearly 90% of Israel’s wastewater is treated for reuse, and 85% of this water has been used in agricultural irrigation since the 1970s.

With the next highest wastewater recycling rate, Spain reuses about 20% of its water and applies nearly 71% to agriculture. 

Australia, China, Greece, Italy, Kuwait, Mexico, Singapore, several African nations, and others safely and effectively use recycled water to manage agricultural production and drinking water. 

Singapore is also a famous example of water recycling. The country’s high-density population of 699 residents per square kilometre contributes to its increasing water shortage. Singapore could reuse its wastewater using a state-of-the-art treatment process that combines microfiltration, reverse osmosis, and UV radiation. They call this recycled water “NEWater,” which is used for industrial applications, and a portion of it is fed into its drinking water network.

Barriers to fully embracing “NEWater” in Singapore are mainly psychological factors, also known as the “yuck factor,” which is an emotional response or attitude towards recycled or reused water. However, a 2017 study shows that 74% of Singaporeans approve of NEWater. The study notes that one reason NEWater is so well accepted among Singaporeans is its contribution to self-sufficiency and national security.

Countries at the bottom of water recycling

China’s strong focus on water treatment has led to poor water recycling. Only 10% is recycled. This low percentage is caused mainly by poor water quality, which means that even when the water is treated, it does not achieve sufficient quality for reuse.

A new study by scientists at Utrecht University and the United Nations University shows that about half of global wastewater is treated, rather than the previous estimate of 20%. Despite this promising finding, the authors warn that treatment rates in developing countries are still very low.

The graph below, based on data from Utrecht University, shows which countries treat and reuse water the most and which do not. The university suggests that the low treatment level is related to low income in the regions. So, it is no surprise that African countries fall behind in wastewater treatment.

Countries like Chad, Congo, Somalia, and Sudan treat less than 5% of their wastewater. Morocco, Algeria, South Africa, and Botswana scored a little better. They treat between 25 to 50% of their wastewater. These poor figures also mean these African countries need better wastewater treatment and infrastructure. These countries suffer extreme droughts and water scarcity so that they could benefit most from water recycling.

Barriers to wide acceptance of recycled water

While wastewater reuse is a solution for the future, barriers still exist in fully accepting and implementing water reuse and recycling on a large scale. First, it faces the issue of social acceptability. For example, a recent survey in Kuwait showed that the two main fears about “reuse” for domestic use were health risks (69%) and an aversion to such use (44%) (Medret, 2019).

Another challenge is the limited application of recycled water, mainly restricted to irrigation, groundwater recharge, or industrial uses. However, Singapore’s advanced water treatment and filtration technology has improved recycled water quality to make it safe for consumption.

Another drawback of recycled water is its high salinity content, which can harm crop and soil quality, and inadequate filtration of emerging pollutants known as micropollutants can be “micropollutants,” identified as endocrine disruptors.