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Efficient Ultra Pure Water Production

The production of electricity at the USVI Water & Power Authority (WAPA) Randolph Harley Power Plant in the US Virgin Islands depends on a reliable supply of ultra-pure water. WAPA’s existing system was dated and inefficient resulting in costly production of make-up water.

Seven Seas Water partnered with WAPA to provide 550,000 GPD (2,081m3/d) of ultra-pure water under a Build-Own-Operate (BOO) arrangement for 20 years. The plant was up and running in a mere 97 days meeting the EPA’s discharge mandate.

From a seawater reverse osmosis permeate; Seven Seas Water’s system utilizes brackish water reverse osmosis that produces high-purity water at 5 μS/cm, and electro deionization that produces ultra-pure water at 0.06 μS/cm. Each process step is operating at 90% recovery. The plant is sized so all components are 100% redundant to meet their estimated nominal production requirement of 235,000 GPD (889 m3/d).

Seven Seas Water managed all aspects of the project with no upfront capital requirements from WAPA and is currently responsible for 24/7/365 operations of the ultra-pure water plant.