It may be hard to quantify exactly how much wastewater is being recycled, but its benefits are clear
The benefits of wastewater reuse are well known. Where water resources are stressed, it can be a lifeline, increasing the supply of available water, maximizing its use, and allowing business and industry to operate in harmony with communities. It can nurture surrounding ecosystems and agriculture.
As we seek to quantify the need for reuse, several figures stand out. For example:
- 80% of the planet’s wastewater is inadequately treated or not treated at all, creating a global ecological and public health threat.
- 36% of the world’s population lives with water scarcity.
- Demand for water is projected to climb to 55% by 2050.
Water reuse presents a single, elegant solution to both climbing demand and pollution. It’s an entry point to a circular economy that increases both sustainability and climate resilience.
Do the numbers justify wastewater reuse financially? While economic feasibility studies place many proposed reuse projects in the marginal or unfeasible categories, a Spanish research team cautioned that traditional assessments underestimate the feasibility of reuse.
Studies generally focus on internal costs, while external economic impacts, like those from environmental improvement and increased resource availability (say, increased tourism due to a cleaner beach), are given only cursory attention.
The team studied 13 reuse plants in Spain with both methods. When they used the internal benefit analyses, only a portion of projects were economically viable. When external benefits were considered, all were.
How Big Is Wastewater Reuse?
Because of advances being made on the national and local levels, it’s difficult to put a number on how widely wastewater recycling is being adopted. Here are some individual examples:
- On the national scale, Israel touts a national wastewater reuse rate of nearly 90%. The Shafdan reuse facility, Israel’s largest, treats 97 million GPD (367,000 m3/d) of Tel Aviv’s municipal wastewater and pipes it to farms in the Negev Desert.
- In industry, a paper mill in Durban, South Africa, has been treating and reusing enough water to fill 13 Olympic-sized swimming pools every day since 2001.
- On the municipal scale, Los Angeles’ Operation Next plans to recycle 100% of its 580 million GPD (2.2 million m3/d) wastewater capacity by 2035, with plans for capacity increases.
Direct potable reuse, which highly purifies wastewater for drinking, also is growing. The city of Windhoek, Namibia, treats and reuses its domestic wastewater to supply 5.5 million GPD (21,000 m3/d) of drinking water, which accounts for 35% of the supply for the city’s 400,000 inhabitants.
Decentralized Wastewater Reuse
While showing the largest reuse projects grabs attention, thinking too big may be a trap. Today, decentralized treatment is frequently the best option, yet it is overlooked all too often. Decentralized wastewater treatment and reuse is characterized by smaller plants sited where they’re required, radically shrinking CAPEX and OPEX while increasing water quality and operational efficiency.
Let’s look at one example scenario in which decentralized wastewater treatment and reuse can be a lifeline. Small Bahamian islands may have beautiful beaches and blue seawater, but they are increasingly parched, and improper wastewater treatment — or in too many cases, no wastewater treatment — can ruin the aquatic ecosystems and beaches that support tourism.
At the Sandals resort on Great Exuma cay in the Bahamas, a Seven Seas Water Group project treats 400,000 GPD (3,780 m3/d) of resort wastewater for safe irrigation of the golf course while keeping pollution out of the surrounding waters. The project also features a desalination plant to provide drinking water.
A Focus on Sustainability
In a world where demand for fresh water is increasing and supply is diminishing, recycling wastewater is growing in importance. It plays a key role in plans to meet the United Nation’s Sustainable Development Goal 6, “Clean Water and Sanitation.”
Contact Seven Seas Water Group. Our wastewater solutions treat billions of gallons per year in plants around the globe, and our experts can help identify your wastewater reuse opportunities.
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