Removing the salt and other minerals from sea water has always been an expensive process, due to the cost of both building and operating plants. Seven Seas Water handles the process for Caribbean municipalities, as well as hotels and other private facilities.

The company, which is based on the island of St. Thomas, designs, builds and operates its own facilities in locales where fresh water is both expensive and scarce, bringing in a continuous cash flow for investors.

The $20 million round was led by TPG Growth and Element Partners, according to VentureWire (subscription required). Virgin Green Fund, Advent-Morro Equity Partners and CEO Doug Brown also participated.