Is Desalination Sustainable?

Nov 13, 2023
 by Seven Seas News Team

Reverse osmosis is the most cost-efficient and widely used technology for desalinating seawater, and technological advances have resulted in a significant reduction in energy consumption.

Technological advancements mean desalination processes require less energy for the same result

As we delve into the sustainability of desalination, let’s first explore the pivotal role seawater desalination plays in ensuring an adequate and secure water supply, which is one of the biggest hurdles to development in many regions of the world. Water is vital for life on our planet, and the availability of sustainable sources of fresh water is increasingly limited. Population expansion, changing water-use patterns, and climate change pose significant threats to those resources.

One problem is aquifer degradation from overextraction of fresh groundwater, as well as saltwater intrusion caused by rising sea levels. Another is contamination of surface waters by the discharge of agricultural, industrial, and municipal wastewater, which further reduces the quality of fresh water.

If we hope to achieve the United Nations Sustainable Development goal of clean water and sanitation for all by 2030, we must manage our water resources more sustainably.

Seawater Desalination Is Key

Desalinating seawater is one of the most viable means of supplying fresh water for an expanding population and for ensuring water resilience as the climate changes. However, some environmental advocates are concerned about the ecological impacts that desalination facilities can have. When contemplating desalination, developers must take into account site selection, environmental consequences, compliance with local regulations, and more.

Reverse osmosis is the most cost-efficient and widely used technology for desalinating seawater. Technological advances like energy recovery systems have resulted in a significant reduction in energy consumption, a reduction that is likely to continue improving.

Building Environmentally Sustainable Desalination Plants

While Seven Seas Water Group’s desalination and Water-as-a-Service® (WaaS®) solutions are designed to address common water challenges, including access to safe drinking water in water-scarce regions or developing countries with limited capital, the company also ensures that this is achieved without compromising the environment.

At Seven Seas, sustainability is an integral part of our mission: Ensuring a clean water supply for all. We’re focused on building sustainability into our water treatment technologies, and wherever possible are deploying renewable energy sources, reducing energy consumption and its associated greenhouse gas emissions. Our desalination plants use energy recovery devices (ERDs) to maximize efficiency, and water recycling is integrated into our designs wherever possible, maximizing every drop and reducing the environmental impact associated with wastewater discharge.

Our sustainability efforts have earned us a five-star GRESB rating, as well as silver and gold U.S. Resiliency Council ratings for our resilient plant design, due to their ability to withstand earthquakes and h3 winds.

Desalination plants can be designed to mitigate water-related challenges while maintaining a steadfast focus on reducing their ecological footprint, as demonstrated by the following examples.

Seawater Desalination on St. Maarten

The Caribbean region has long grappled with water supply challenges. Severe droughts have reduced supplies of fresh water, while demand has surged because of population growth and a thriving tourism sector.

On the island of St. Maarten, an aging desalination plant’s daily output fell hundreds of thousands of gallons below its initial capacity. Not only did the plant require refurbishment, but a new facility had to be built to meet escalating demand.

Seven Seas provided a state-of-the-art seawater reverse osmosis (SWRO) plant with a capacity of 1 million GPD (3,785 m3/d) through a WaaS® agreement. This build-own-operate-transfer arrangement required no initial investment, and the new facility was up and running in less than five months, with Seven Seas experts responsible for its operation and maintenance.

Seven Seas also renovated a plant at Cay Bay, elevating its capacity by nearly a million GPD. The SWRO technology led to a 30% reduction in energy consumption, minimizing the plant’s carbon footprint and enhancing its environmental sustainability.

Complete Water Cycle Solution for Turks and Caicos Islands

The Leeward Estates complex in Turks and Caicos encompasses residential areas, a resort, and a mega-yacht marina. The developer required a comprehensive water management solution that could be implemented in phases to align with the expansion of the development, reducing initial capital outlay requirements.

Given the water scarcity in Turks and Caicos, the primary source of drinking water is seawater treated with reverse osmosis desalination. For the Leeward Estates project, the developer also wanted to include treatment of wastewater for nonpotable reuse, for a more cost-effective approach to obtaining irrigation water.

Across the region, a substantial portion of wastewater is discharged without proper treatment, leading to significant damage to coral reefs and affecting tourism. In contrast, Leeward Estates wastewater is treated to produce a dependable, economical supply of safe irrigation water while also safeguarding the local environment.

Seven Seas installed a modular SWRO plant, delivering 250,000 GPD (946 m³/d) of desalinated water, with 50,000 GPD of recycled wastewater from modular membrane bioreactor treatment.

Leading the Way in Sustainable Desalination

In an era where water is ever scarcer, seawater desalination offers hope for addressing this challenge, particularly through eco-friendly methods and innovative technologies.

Seven Seas stands at the forefront of this effort, not only by providing advanced desalination solutions but also by integrating environmental sustainability. The company’s commitment to energy efficiency, renewable energy compatibility, and responsible water recycling sets a high standard for the industry.

If you are looking to bolster water security while also safeguarding the planet, contact Seven Seas to learn more about how our desalination technologies can build resilience without harming the environment.