Reverse osmosis replaces thermal process and transforms water treatment
In the heart of the Caribbean lies the United States Virgin Islands (USVI), a paradise blessed with abundant rain but challenged by its unique climate, geology, and terrain in accessing safe drinking water. To tackle this vital issue, the territory embraced desalination, venturing into various methods to meet its water needs.
The U.S. Virgin Islands holds a unique distinction – it’s one of the few places where all four major desalination processes have been implemented at a commercial scale: distillation, freezing, electrodialysis, and reverse osmosis. By the 1980s, the Virgin Islands’ Water and Power Authority (WAPA) had come to rely on desalination for 80% of its public water supply, highlighting the crucial role of desalination in this tropical paradise.
Desalination Plants Needed to Be Modernized
Over time, the older desalination plants, initially built around energy-intensive thermal desalination, struggled with soaring energy costs. In contrast, reverse osmosis was becoming increasingly cost-effective and energy-efficient. As the outdated thermal plants began to show their age, the time was ripe for a desalination revolution, led by reverse osmosis.
While modern reverse osmosis plants offered efficiency, they also came with significant upfront costs and complex long-term operations and maintenance (O&M) requirements. Here, Seven Seas Water Group’s Water-as-a-Service® (WaaS®) financing emerged as a game-changer. It eliminated these obstacles by providing new plants without an initial cost, with the Seven Seas team handling the vital long-term O&M.
The St. Croix Story
The journey began on the island of St. Croix in 2009, when WAPA decided to refurbish its aging thermal desalination equipment. Seven Seas swiftly deployed a temporary seawater reverse osmosis (SWRO) plant, capable of delivering 500,000 gallons daily. To WAPA’s delight, the plant exceeded expectations, providing freshwater below cost estimates.
Impressed by the SWRO plant’s performance, WAPA expanded its scope to 1.5 million gallons per day. Remarkably, within just 92 days, Seven Seas was delivering the full volume of water, solidifying WAPA’s trust. This marked the beginning of a fruitful partnership.
St. Thomas’ Emergency Solution
As plans to replace St. Thomas’ thermal desalination units with a 2.2 million gallons per day facility were underway, a crisis emerged due to a breakdown. In a mere 29 days, Seven Seas commissioned emergency capacity, and in an additional 19 days, had completed the full scope of this water treatment project, comprised of eight containerized units delivering 2 million gallons daily. This swift response demonstrated Seven Seas’ commitment.
Today, St. Thomas and St. John benefit from a permanent Harley seawater reverse osmosis facility, delivering 3.3 million gallons daily. St. Croix boasts the Richmond SWRO facility, providing 2.2 million gallons daily, alongside the original 1.5 million-gallon plant.
With quick deploy containerized units in place on St. Croix and St. Thomas, WAPA and Seven Seas began coordinating efforts to build permanent facilities on both islands.
Providing Ultrapure Water to Power the Virgin Islands
In a significant step forward, Seven Seas implemented brackish water reverse osmosis (BWRO) and electrodeionization (EDI) on St. Croix and St. Thomas. Together, these systems produce 850,000 gallons daily of ultrapure water for boiler feed water and scrubbers in the territory’s power plants.
Seven Seas’ achievements in the Virgin Islands exemplify how modernized desalination systems can swiftly revolutionize water access. WaaS® financing, paired with long-term O&M, is the driving force behind this transformative journey. For your own system’s transformation, contact the experts at Seven Seas. Together, we can secure a cleaner, brighter future, drop by drop.
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